阅读说明：本技术 一种节流装置 (Throttling device ) 是由 刘雄 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种节流装置,它由第一旁流管、第二旁流管、节流机构、第一单向阀、第二单向阀、第三单向阀、第四单向阀、第三旁流管、第五单向阀、常开电磁阀组成；第一单向阀出口端与第一旁流管相连,第一单向阀入口端依次通过第五十八管道、第二单向阀入口端、第二单向阀出口端与第二旁流管相连；第三单向阀入口端与第二旁流管相连,第三单向阀出口端依次通过第四单向阀出口端、第四单向阀入口端与第一旁流管相连；其特点是：在运行过程中,用一个节流机构就能实现制热、制冷、室外换热器交替化霜等多种功能的节流工作；工作更稳定、可靠；结构简单,成本低廉；本发明适用于工业和民用的空气源热泵,特别适用于低温环境的场合。(The invention discloses a throttling device, which consists of a first bypass pipe, a second bypass pipe, a throttling mechanism, a first check valve, a second check valve, a third check valve, a fourth check valve, a third bypass pipe, a fifth check valve and a normally open electromagnetic valve, wherein the first bypass pipe is connected with the second bypass pipe; the outlet end of the first check valve is connected with the first bypass pipe, and the inlet end of the first check valve is connected with the second bypass pipe through a fifth eighteenth pipeline, the inlet end of the second check valve and the outlet end of the second check valve in sequence; the inlet end of the third one-way valve is connected with the second bypass pipe, and the outlet end of the third one-way valve is connected with the first bypass pipe through the outlet end of the fourth one-way valve and the inlet end of the fourth one-way valve in sequence; the method is characterized in that: in the operation process, the throttling work with multiple functions of heating, refrigerating, outdoor heat exchanger alternative defrosting and the like can be realized by using one throttling mechanism; the work is more stable and reliable; the structure is simple, and the cost is low; the invention is suitable for industrial and civil air source heat pumps, and is particularly suitable for occasions in low-temperature environments.)

1. The throttling device comprises a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first check valve (23), a second check valve (24), a third check valve (25) and a fourth check valve (26), and is characterized in that: the throttling device also comprises a third bypass pipe (55), a fifth one-way valve (28) and a normally open electromagnetic valve (7);

the outlet end of the first check valve (23) is connected with a first bypass pipe (56), and the inlet end of the first check valve (23) is connected with a second bypass pipe (57) through a fifth eighteenth pipeline (58), the inlet end of a second check valve (24) and the outlet end of the second check valve (24) in sequence;

the inlet end of the third check valve (25) is connected with the second bypass pipe (57), and the outlet end of the third check valve (25) is connected with the first bypass pipe (56) through the outlet end of the fourth check valve (26) and the inlet end of the fourth check valve (26) in sequence;

the outlet end of the throttling mechanism (6) is connected with a fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26);

one end of the normally open electromagnetic valve (7) is connected with the third bypass pipe (55), and the other end of the normally open electromagnetic valve (7) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through a fifty-fourth pipeline (54);

the inlet end of the fifth check valve (28) is connected with a fifty-eighth pipeline (58), and the outlet end of the fifth check valve (28) is connected with the third bypass pipe (55).

2. A throttle device according to claim 1, characterized in that the inlet end of a sixth one-way valve (29) is connected to the third bypass pipe (55) through said normally open solenoid valve (7), and the outlet end of said sixth one-way valve (29) is connected to a fifty-fourth pipe (54).

3. A throttle device according to any one of claims 1-2, characterized in that one end of a bypass flow capillary is connected to one end of the normally open solenoid valve (7), and the other end of the bypass flow capillary is connected to the other end of the normally open solenoid valve (7).

4. A restriction device according to any one of claims 1-2, wherein an inlet side of the reservoir (11) is connected to a conduit between the outlet side of the third one-way valve (25) and the outlet side of the fourth one-way valve (26); the outlet end of the liquid reservoir (11) is connected with a pipeline at the inlet end of the throttling mechanism (6).

5. A restriction device according to claim 3, characterized in that an inlet side of the reservoir (11) is connected to the conduit between the outlet side of the third non return valve (25) and the outlet side of the fourth non return valve (26); the outlet end of the liquid reservoir (11) is connected with a pipeline at the inlet end of the throttling mechanism (6).

6. A throttle device according to any one of claims 1-2, characterized in that an economizer (10) is mounted on the inlet end pipe of the throttle means (6).

7. A throttle device according to claim 3, characterized in that an economizer (10) is mounted on the inlet end pipe of the throttle means (6).

8. A restriction device according to claim 4, characterized in that an economizer (10) is arranged in the conduit between the inlet end of the restriction device (6) and the outlet end of the reservoir (11).

9. A restriction device according to claim 5, characterized in that an economizer (10) is arranged in the conduit between the inlet end of the restriction device (6) and the outlet end of the reservoir (11).

10. The throttling device comprises a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first check valve (23), a second check valve (24), a third check valve (25) and a fourth check valve (26), and is characterized in that: the throttling device also comprises a third bypass pipe (55) and a normally open electromagnetic valve (7);

the outlet end of the first check valve (23) is connected with a first bypass pipe (56), and the inlet end of the first check valve (23) is connected with a second bypass pipe (57) through a fifth eighteenth pipeline (58), the inlet end of a second check valve (24) and the outlet end of the second check valve (24) in sequence;

the inlet end of the third check valve (25) is connected with the second bypass pipe (57), and the outlet end of the third check valve (25) is connected with the first bypass pipe (56) through the outlet end of the fourth check valve (26) and the inlet end of the fourth check valve (26) in sequence;

the outlet end of the throttling mechanism (6) is connected with a fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26);

one end of the normally open electromagnetic valve (7) is connected with the third bypass pipe (55), and the other end of the normally open electromagnetic valve (7) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through a fifty-fourth pipeline (54).

Technical Field

The invention relates to a throttling device for an air source heat pump, and belongs to the technical field of refrigeration.

Background

The invention patent with patent number 201110355046.1, granted at 12/10/2014 by the applicant of the present invention, provides an air conditioning and refrigerating device, the system composition of which is shown in fig. 4, and the air conditioning and refrigerating device can be used as an air source heat pump which can absorb heat from outdoor air and continuously supply heat and defrost when in practical application. As shown in fig. 4, the air-source heat pump has at least two sets of outdoor heat exchangers, namely a first outdoor heat exchanger 4 and a second outdoor heat exchanger 5; when the first outdoor heat exchanger 4 needs defrosting, the first four-way valve 70 is switched; and the second four-way valve 80 is not switched, the second outdoor heat exchanger 5 still works normally, heat is absorbed from outdoor air, one part of the absorbed heat is supplied to the first outdoor heat exchanger 4 for defrosting, and the other part of the absorbed heat can continue to supply heat through the heater 3.

Similarly, when the second outdoor heat exchanger 5 needs defrosting, the second four-way valve 80 switches; and the first four-way valve 70 is not switched, the first outdoor heat exchanger 4 still works normally, heat is absorbed from outdoor air, one part of the absorbed heat is supplied to the second outdoor heat exchanger 5 for defrosting, and the other part of the absorbed heat can continue to supply heat through the heater 3.

During operation, the heater 3 is always at condensing pressure, with no risk of freezing; however, compared with a conventional air source heat pump (as shown in fig. 5), the system is provided with two sets of outdoor heat exchangers, namely a first outdoor heat exchanger 4 and a second outdoor heat exchanger 5, wherein the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are respectively provided with two electronic expansion valves, namely a first electronic expansion valve 7 and a second electronic expansion valve 8; in the working process, the refrigerant flow passing through the first outdoor heat exchanger 4 and the refrigerant flow passing through the second outdoor heat exchanger 5 are respectively regulated and controlled by the first electronic expansion valve 7 and the second electronic expansion valve 8, because the two electronic expansion valves can mutually influence each other in the regulation and control process, compared with the conventional system shown in fig. 5, the regulation and control requirement of the controller is more complex, the time for the unit to reach the stable operation state is longer, and particularly, the normal operation of the unit is recovered after the unit is defrosted.

Disclosure of Invention

The invention aims at an air source heat pump which can absorb heat from outdoor air and can continuously supply heat and defrost, and provides a throttling device which can realize the throttling work of heating, refrigerating, defrosting alternatively of an outdoor heat exchanger and other functions by using a throttling mechanism in the operation process and has a simple structure.

In order to overcome the problems of the prior art, the technical scheme for solving the technical problems is as follows:

1. the throttling device comprises a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first check valve (23), a second check valve (24), a third check valve (25) and a fourth check valve (26), and is characterized in that: the throttling device also comprises a third bypass pipe (55), a fifth one-way valve (28) and a normally open electromagnetic valve (7);

the outlet end of the first check valve (23) is connected with a first bypass pipe (56), and the inlet end of the first check valve (23) is connected with a second bypass pipe (57) through a fifth eighteenth pipeline (58), the inlet end of a second check valve (24) and the outlet end of the second check valve (24) in sequence;

the inlet end of the third check valve (25) is connected with the second bypass pipe (57), and the outlet end of the third check valve (25) is connected with the first bypass pipe (56) through the outlet end of the fourth check valve (26) and the inlet end of the fourth check valve (26) in sequence;

the outlet end of the throttling mechanism (6) is connected with a fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26);

one end of the normally open electromagnetic valve (7) is connected with the third bypass pipe (55), and the other end of the normally open electromagnetic valve (7) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through a fifty-fourth pipeline (54);

the inlet end of the fifth check valve (28) is connected with a fifty-eighth pipeline (58), and the outlet end of the fifth check valve (28) is connected with the third bypass pipe (55).

2. The throttling device comprises a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first check valve (23), a second check valve (24), a third check valve (25) and a fourth check valve (26), and is characterized in that: the throttling device also comprises a third bypass pipe (55) and a normally open electromagnetic valve (7);

the outlet end of the first check valve (23) is connected with a first bypass pipe (56), and the inlet end of the first check valve (23) is connected with a second bypass pipe (57) through a fifth eighteenth pipeline (58), the inlet end of a second check valve (24) and the outlet end of the second check valve (24) in sequence;

the inlet end of the third check valve (25) is connected with the second bypass pipe (57), and the outlet end of the third check valve (25) is connected with the first bypass pipe (56) through the outlet end of the fourth check valve (26) and the inlet end of the fourth check valve (26) in sequence;

the outlet end of the throttling mechanism (6) is connected with a fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26);

one end of the normally open electromagnetic valve (7) is connected with the third bypass pipe (55), and the other end of the normally open electromagnetic valve (7) is connected with a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through a fifty-fourth pipeline (54).

Compared with the prior art, the invention has the beneficial effects that:

1. when the air conditioner runs, the throttling work with multiple functions of heating, refrigerating, outdoor heat exchanger alternative defrosting and the like can be realized by using one throttling mechanism according to the requirement;

2. the work is more stable and reliable;

3. the structure is simple, and the cost is low;

4. the invention is suitable for industrial and civil air source heat pumps, and is particularly suitable for occasions in low-temperature environments.

Drawings

FIG. 1 is a schematic view of the throttle device of the present invention;

FIG. 2 is a schematic structural view of example 1 of the present invention;

FIG. 3 is a schematic structural view of embodiments 2 to 5 of the present invention;

FIG. 4 is a prior art schematic;

FIG. 5 is a schematic view of a prior art structure;

FIG. 6 is a schematic structural view of a modified version of the throttling device of the present invention;

fig. 7 is a schematic structural diagram of embodiment 6 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example 1

Fig. 1 is a schematic structural diagram of the throttling device of the present invention, and the whole throttling device comprises the following components: the first bypass pipe 56, the second bypass pipe 57, the throttle mechanism 6, the first check valve 23, the second check valve 24, the third check valve 25, the fourth check valve 26, the third bypass pipe 55, the fifth check valve 28, and the normally open solenoid valve 7.

The connection relationship of each component is as follows: the outlet end of the first check valve 23 is connected with a first bypass pipe 56, and the inlet end of the first check valve 23 is connected with a second bypass pipe 57 through a fifth eighteen pipeline 58, the inlet end of the second check valve 24 and the outlet end of the second check valve 24 in sequence; the inlet end of the third check valve 25 is connected with the second bypass pipe 57, and the outlet end of the third check valve 25 is connected with the first bypass pipe 56 through the outlet end of the fourth check valve 26 and the inlet end of the fourth check valve 26 in sequence; the outlet end of the throttling mechanism 6 is connected with a fifty-eighth pipeline 58, and the inlet end of the throttling mechanism 6 is connected with a pipeline between the outlet end of the third one-way valve 25 and the outlet end of the fourth one-way valve 26; one end of the normally open electromagnetic valve 7 is connected with a third bypass pipe 55, and the other end of the normally open electromagnetic valve 7 is connected with a pipe between the outlet end of the third one-way valve 25 and the outlet end of the fourth one-way valve 26 through a fifty-four pipe 54; the inlet end of the fifth check valve 28 is connected to a fifty-eighth line 58 and the outlet end of the fifth check valve 28 is connected to a third bypass line 55.

Fig. 2 shows an air source heat pump which can absorb heat from outdoor air and can continuously supply heat and defrost by using the throttling device shown in fig. 1, and is used for occasions with heating and cooling requirements.

The whole equipment comprises the following components: a compression mechanism 1, a first four-way valve 70, a second four-way valve 80, a first outdoor heat exchanger 4, a second outdoor heat exchanger 5, a user heat exchanger 3, a seventh check valve 21, an eighth check valve 22, and a throttle device 100.

The air source heat pump can realize the functions of heating, absorbing heat from outdoor air and alternately defrosting and refrigerating in the operation process.

The workflow under each function is as follows.

(1) Heating function

When the heat pump works normally, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers and are used as evaporators for absorbing heat from the environment; the user side heat exchanger 3 serves as a condenser for heating a user.

The throttle mechanism 6 works normally for throttling, and an electronic expansion valve is usually used. The normally open solenoid valve 7 is opened and the normally closed solenoid valve 8 is closed.

In operation, a high pressure node 71 of first four-way valve 70 communicates with a first direction change node 72 of first four-way valve 70, and a second direction change node 74 of first four-way valve 70 communicates with a low pressure node 73 of first four-way valve 70. The high pressure node 81 of the second four-way valve 80 communicates with a first commutation node 82 of the second four-way valve 80 and a second commutation node 84 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant enters a sixty-th pipeline 60 and is divided into two paths; the first path sequentially passes through a sixteenth pipeline 60, a high-pressure node 71 of a first four-way valve 70, a first reversing node 72 of the first four-way valve 70, an inlet end of an eighth one-way valve 22 and an outlet end of the eighth one-way valve 22, and enters a fifty-first pipeline 51;

the second path sequentially passes through a sixteenth pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a first reversing node 82 of the second four-way valve 80, an inlet end of a seventh one-way valve 21 and an outlet end of the seventh one-way valve 21 and also enters a fifty-first pipeline 51;

two paths of refrigerant are mixed in a fifty-first pipeline 51, enter a user heat exchanger 3 and supply heat for a user, refrigerant gas in the refrigerant gas is changed into liquid after releasing heat, the refrigerant liquid passes through a third bypass pipe 55, a normally open electromagnetic valve 7, a fifty-fourth pipeline 54 and the inlet end of a throttling mechanism 6 after coming out of the user heat exchanger 3, enters the throttling mechanism 6 and is throttled, and the throttled refrigerant enters a fifty-eighth pipeline 58 and is divided into two paths after coming out of the outlet end of the throttling mechanism 6;

the first path sequentially passes through the inlet end of the second one-way valve 24, the outlet end of the second one-way valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, the sixty-seventh pipeline 67, the second reversing node 84 of the second four-way valve 80 and the low-pressure node 83 of the second four-way valve 80, and enters the sixty-fifth pipeline 65;

the second path sequentially passes through the inlet end of the first check valve 23, the outlet end of the first check valve 23, the first bypass pipe 56, the first outdoor heat exchanger 4, the sixty-fourth pipeline 64, the second reversing node 74 of the first four-way valve 70, the low-pressure node 73 of the first four-way valve 70 and also enters the sixty-fifth pipeline 65; the two paths are mixed in a sixty-five pipeline 65, then return to the inlet end of the compression mechanism 1, enter the compression mechanism 1 and are compressed again, and a cycle is completed.

(2) Heat absorption and alternative defrosting function from outdoor air

When the electromagnetic valve works under the function, the normally open electromagnetic valve 7 and the normally closed electromagnetic valve 8 are closed. The throttle mechanism 6 works normally and the user heat exchanger 3 does not work. The two groups of outdoor heat exchangers alternately defrost. The working processes are respectively as follows.

1) When the first outdoor heat exchanger 4 is defrosted, the second outdoor heat exchanger 5 operates normally to absorb heat from the outdoor air

At this time, the second four-way valve 80 does not operate and maintains the state during the heating function;

the first four-way valve 70 is switched, and the communication relationship among the four nodes is as follows: the high pressure node 71 of the first four way valve 70 communicates with the second commutation node 74 of the first four way valve 70 and the first commutation node 72 of the first four way valve 70 communicates with the low pressure node 73 of the first four way valve 70.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant sequentially passes through a sixty-th pipeline 60, a high-pressure node 71 of the first four-way valve 70, a second reversing node 74 of the first four-way valve 70, a sixty-fourth pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26, the outlet end of the fourth check valve 26, the inlet end of the throttling mechanism 6, the outlet end of the throttling mechanism 6, a fifty-eighth pipeline 58, the inlet end of the second check valve 24, the outlet end of the second check valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, a sixty-seventh pipeline 67, a second reversing node 84 of the second four-way valve 80 and a low-pressure node 83 of the second four-way valve 80, and enters the sixty-fifth pipeline 65; and then returning to the inlet end of the compression mechanism 1, entering the compression mechanism 1 and being compressed again, and completing one cycle.

2) When the second outdoor heat exchanger 5 is defrosted, the first outdoor heat exchanger 4 normally operates to absorb heat from the outdoor air

At this time, the first four-way valve 70 does not operate, and the state during the heating function is still maintained;

the second four-way valve 80 is switched, and the communication relationship among the four nodes is as follows: the high pressure node 81 of the second four-way valve 80 communicates with a second commutation node 84 of the second four-way valve 80 and the first commutation node 82 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant sequentially passes through a sixty-th pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a second reversing node 84 of the second four-way valve 80, a sixty-seventh pipeline 67, the second outdoor heat exchanger 5, a second bypass pipe 57, an inlet end of a third check valve 25, an outlet end of the third check valve 25, an inlet end of a throttling mechanism 6, an outlet end of a throttling mechanism 6, a fifty-eighth pipeline 58, an inlet end of a first check valve 23, an outlet end of a first check valve 23, a first bypass pipe 56, a first outdoor heat exchanger 4, a sixty-fourth pipeline 64, a second reversing node 74 of a first four-way valve 70 and a low-pressure node 73 of the first four-way valve 70, and enters a sixty-fifth pipeline 65; and then returning to the inlet end of the compression mechanism 1, entering the compression mechanism 1 and being compressed again, and completing one cycle.

(3) Refrigeration function

When the air conditioner works normally, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers and are used as condensers to emit condensation heat generated by refrigeration to the environment; the user side heat exchanger 3 serves as an evaporator to refrigerate a user.

The throttle mechanism 6 works normally for throttling. The normally open solenoid valve 7 is closed and the normally closed solenoid valve 8 is opened.

In operation, the high pressure node 71 of the first four-way valve 70 communicates with the second commutation node 74 of the first four-way valve 70, and the first commutation node 72 of the first four-way valve 70 communicates with the low pressure node 73 of the first four-way valve 70. The high pressure node 81 of the second four-way valve 80 communicates with a second commutation node 84 of the second four-way valve 80 and the first commutation node 82 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant enters a sixty-th pipeline 60 and is divided into two paths; the first path sequentially passes through a sixty-th pipeline 60, a high-pressure node 71 of a first four-way valve 70, a second reversing node 74 of the first four-way valve 70, a sixty-fourth pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of a fourth check valve 26 and the outlet end of the fourth check valve 26, and enters an inlet pipeline of the throttling mechanism 6;

the second path sequentially passes through a sixty-th pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a second reversing node 84 of the second four-way valve 80, a sixty-seventh pipeline 67, the second outdoor heat exchanger 5, a second bypass pipe 57, an inlet end of a third check valve 25, an outlet end of the third check valve 25 and also enters an inlet-end pipeline of the throttling mechanism 6; the two paths are mixed in the pipeline at the inlet end of the throttling mechanism 6, and then enter the throttling mechanism 6 to be throttled into a low-temperature low-pressure gas-liquid two-phase mixture, and after the mixture comes out from the pipeline at the outlet end of the throttling mechanism 6, the mixture sequentially passes through a fifth eighteenth pipeline 58, the inlet end of a fifth one-way valve 28, the outlet end of the fifth one-way valve 28, a third bypass pipe 55, the user heat exchanger 3, a fifty-first pipeline 51, a normally closed electromagnetic valve 8, a first reversing node 82 of a second four-way valve 80, a low-pressure node 83 of the second four-way valve 80 and a sixty-fifth pipeline 65, returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 and is compressed again, and a cycle is completed.

Example 2

The restriction device shown in fig. 1 can be further improved by adding a sixth non-return valve 29 to the solution shown in fig. 1; as shown in fig. 3, the connection relationship of the sixth check valve 29 in the system is as follows: the inlet end of the sixth check valve 29 is connected with the third bypass pipe 55 through the normally open electromagnetic valve 7, and the outlet end of the sixth check valve 29 is connected with the fifty-fourth pipeline 54.

The benefit of adding the sixth one-way valve 29 is: when the scheme shown in fig. 2 works under the refrigeration function, the normally open solenoid valve 7 can not work, i.e. is not electrified, and still keeps an open state; therefore, the working environment of the normally open electromagnetic valve 7 can be improved, and the long-time electrification of the normally open electromagnetic valve can be avoided when the normally open electromagnetic valve operates under the refrigeration function.

After the sixth check valve 29 is added, the normally open electromagnetic valve 7 is electrified for a short time only when the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are alternately defrosted in winter, and is not electrified and does not work when working under the refrigeration and heating functions, so that the fault rate of the normally open electromagnetic valve 7 can be reduced, and the service life of the normally open electromagnetic valve is prolonged.

Example 2 the protocol described is applicable to all protocols of all examples of the invention.

Example 3

The throttling device shown in fig. 1 can be further improved by adding a bypass capillary in the solution shown in fig. 1; the connection relationship of the bypass capillary in the system is as follows: one end of the bypass flow capillary is connected with one end of the normally open solenoid valve 7, and the other end of the bypass flow capillary is connected with the other end of the normally open solenoid valve 7.

The benefits of adding a side-stream capillary are: when the defrosting device works under the function of absorbing heat from outdoor air and alternately defrosting, continuous heating defrosting can be realized. In practical application, the length and the drift diameter of the capillary tube are reasonably selected, so that the time of alternative defrosting can be controlled, and the heat for defrosting and the heat supply quantity at the same time can be adjusted; the capillary length is generally calculated theoretically and then verified experimentally.

After the scheme of example 1 and fig. 2 is added with the bypass capillary, the working flow under the refrigeration function and the heating function is the same as that of example 1, and the working flow under the outdoor air heat absorption and defrosting alternation function is different, which is specifically as follows.

When the outdoor air defrosting device works under the function of absorbing heat and alternately defrosting outdoor air, the normally open electromagnetic valve 7 and the normally closed electromagnetic valve 8 are both closed. The throttle mechanism 6 works normally; the two groups of outdoor heat exchangers are alternatively defrosted, and simultaneously, the user heat exchanger 3 also works. The working processes are respectively as follows.

1) When the first outdoor heat exchanger 4 is defrosted, the second outdoor heat exchanger 5 operates normally to absorb heat from the outdoor air

At this time, the second four-way valve 80 does not operate and maintains the state during the heating function;

the first four-way valve 70 is switched, and the communication relationship among the four nodes is as follows: the high pressure node 71 of the first four way valve 70 communicates with the second commutation node 74 of the first four way valve 70 and the first commutation node 72 of the first four way valve 70 communicates with the low pressure node 73 of the first four way valve 70.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant enters a sixty-th pipeline 60 and is divided into two paths; the first path sequentially passes through a sixty-th pipeline 60, a high-pressure node 71 of a first four-way valve 70, a second reversing node 74 of the first four-way valve 70, a sixty-fourth pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of a fourth check valve 26 and the outlet end of the fourth check valve 26, and enters an inlet pipeline of the throttling mechanism 6;

the second path sequentially passes through a sixteenth pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a first reversing node 82 of the second four-way valve 80, an inlet end of a seventh one-way valve 21, an outlet end of the seventh one-way valve 21, a fifty-first pipeline 51, a user heat exchanger 3, a third bypass flow pipe 55, a bypass flow capillary pipe and a fifty-fourth pipeline 54 and also enters an inlet end pipeline of the throttling mechanism 6; the refrigerant and the first path of refrigerant are mixed in a pipeline at the inlet end of the throttling mechanism 6, then enter the throttling mechanism 6 and are throttled into a low-temperature low-pressure gas-liquid two-phase mixture, and the low-temperature low-pressure gas-liquid two-phase mixture flows out of a pipeline at the outlet end of the throttling mechanism 6, sequentially passes through a fifty-eighth pipeline 58, the inlet end of a second one-way valve 24, the outlet end of the second one-way valve 24, a second bypass pipe 57, a second outdoor heat exchanger 5, a sixty-seventh pipeline 67, a second four-way valve 80, a second reversing node 84 and a low-pressure node 83 of the second four-way valve 80, and then enters a sixty-fifth pipeline 65; and then returning to the inlet end of the compression mechanism 1, entering the compression mechanism 1 and being compressed again, and completing one cycle.

2) When the second outdoor heat exchanger 5 is defrosted, the first outdoor heat exchanger 4 works normally, and when heat is absorbed from outdoor air, the first four-way valve 70 does not act, and the state of the heating function is still maintained;

the second four-way valve 80 is switched, and the communication relationship among the four nodes is as follows: the high pressure node 81 of the second four-way valve 80 communicates with a second commutation node 84 of the second four-way valve 80 and the first commutation node 82 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant enters a sixty-th pipeline 60 and is divided into two paths; the first path sequentially passes through a sixty-th pipeline 60, a high-pressure node 71 of a first four-way valve 70, a first reversing node 72 of the first four-way valve 70, an inlet end of an eighth one-way valve 22, an outlet end of the eighth one-way valve 22 and a fifty-first pipeline 51, enters the user heat exchanger 3 for heating a user, refrigerant gas in the user heat exchanger is changed into liquid after releasing heat, and the refrigerant liquid passes through a third bypass pipe 55, a bypass capillary pipe and a fifty-fourth pipeline 54 after coming out of the user heat exchanger 3 and then enters an inlet pipeline of the throttling mechanism 6;

the second path sequentially passes through a sixty-th pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a second reversing node 84 of the second four-way valve 80, a sixty-seventh pipeline 67, the second outdoor heat exchanger 5, a second bypass pipe 57, an inlet end of a third check valve 25, an outlet end of the third check valve 25 and also enters an inlet-end pipeline of the throttling mechanism 6;

the refrigerant and the first path of refrigerant are mixed in an inlet pipeline of the throttling mechanism 6, then enter the throttling mechanism 6 and are throttled into a low-temperature low-pressure gas-liquid two-phase mixture, and the low-temperature low-pressure gas-liquid two-phase mixture flows out of an outlet pipeline of the throttling mechanism 6, sequentially passes through a fifty-eight pipeline 58, an inlet end of a first one-way valve 23, an outlet end of the first one-way valve 23, a first bypass pipe 56, a first outdoor heat exchanger 4, a sixty-four pipeline 64, a first four-way valve 70, a second reversing node 74 and a low-pressure node 73 of the first four-way valve 70, and then enters a sixty-five pipeline 65; and then returning to the inlet end of the compression mechanism 1, entering the compression mechanism 1 and being compressed again, and completing one cycle.

Example 3 the protocol described is applicable to all protocols of all examples of the invention.

Example 4

As shown in fig. 3, the restriction device shown in fig. 1 may be further modified by adding a reservoir 11 to the arrangement shown in fig. 1; the connection of the reservoir 11 in the system is as follows:

the inlet end of the liquid reservoir 11 is connected with a pipeline between the outlet end of the third one-way valve 25 and the outlet end of the fourth one-way valve 26; the outlet end of the liquid reservoir 11 is connected with the pipeline at the inlet end of the throttling mechanism 6.

For larger heat pump units, the presence of the reservoir 11 allows a good adaptation of the refrigerant circulation flow during operation of the heat pump system.

Example 4 the protocol described is applicable to all protocols of all examples of the invention.

Example 5

As shown in fig. 3, the throttle device shown in fig. 1 can be further improved by adding an economizer 10 to the arrangement shown in fig. 1; the connection of the economizer 10 in the system is as follows.

1) The inlet end of the high pressure side of the economizer 10 is connected with a pipeline between the outlet end of the third check valve 25 and the outlet end of the fourth check valve 26; the outlet end of the high-pressure side of the economizer 10 is connected with a pipeline at the inlet end of the throttling mechanism 6; the inlet end of the auxiliary throttling mechanism 9 is connected with a pipeline at the high-pressure side of the economizer 10 or a pipeline at the high-pressure side of the economizer 10, and the outlet end of the auxiliary throttling mechanism 9 is connected with a middle air supplement port of the compression mechanism 1 sequentially through the inlet end at the low-pressure side of the economizer 10 and the outlet end at the low-pressure side of the economizer 10.

2) When a liquid reservoir 11 is also added to the throttling device shown in fig. 1, the economizer 10 is installed on a pipe between the inlet end of the throttling mechanism 6 and the outlet end of the liquid reservoir 11; the connection of the economizer 10 in the system is as follows:

the inlet end of the high-pressure side of the economizer 10 is connected with the outlet end of the liquid reservoir 11; the outlet end of the high-pressure side of the economizer 10 is connected with a pipeline at the inlet end of the throttling mechanism 6; the inlet end of the auxiliary throttling mechanism 9 is connected with a pipeline at the high-pressure side of the economizer 10 or a pipeline at the high-pressure side of the economizer 10, and the outlet end of the auxiliary throttling mechanism 9 is connected with a middle air supplement port of the compression mechanism 1 sequentially through the inlet end at the low-pressure side of the economizer 10 and the outlet end at the low-pressure side of the economizer 10.

During the working process, the economizer has the functions of utilizing the intermediate-pressure refrigerant to supercool the high-pressure liquid refrigerant entering the throttling mechanism 6 and realizing air-supplementing and enthalpy-increasing.

For severe cold and cold regions with low environmental temperature, the economizer is used for supplementing air and increasing enthalpy, so that the performance of the heat pump can be improved.

The protocol described in example 5 also applies to all protocols of all examples of the invention.

Example 6

The throttling device shown in fig. 1 can be further improved when used for a purely heating air source heat pump, and the further improvement scheme is shown in fig. 6, and the difference between the scheme shown in fig. 6 and the scheme shown in fig. 1 is as follows: the solution shown in fig. 6 has the fifth non return valve 28 removed. The whole throttling device comprises the following components: the first bypass pipe 56, the second bypass pipe 57, the throttle mechanism 6, the first check valve 23, the second check valve 24, the third check valve 25, the fourth check valve 26, the third bypass pipe 55, and the normally open solenoid valve 7.

The connection relationship of each component is as follows: the outlet end of the first check valve 23 is connected with a first bypass pipe 56, and the inlet end of the first check valve 23 is connected with a second bypass pipe 57 through a fifth eighteen pipeline 58, the inlet end of the second check valve 24 and the outlet end of the second check valve 24 in sequence; the inlet end of the third check valve 25 is connected with the second bypass pipe 57, and the outlet end of the third check valve 25 is connected with the first bypass pipe 56 through the outlet end of the fourth check valve 26 and the inlet end of the fourth check valve 26 in sequence; the outlet end of the throttling mechanism 6 is connected with a fifty-eighth pipeline 58, and the inlet end of the throttling mechanism 6 is connected with a pipeline between the outlet end of the third one-way valve 25 and the outlet end of the fourth one-way valve 26; one end of the normally open electromagnetic valve 7 is connected with the third bypass pipe 55, and the other end of the normally open electromagnetic valve 7 is connected with a pipe between the outlet end of the third check valve 25 and the outlet end of the fourth check valve 26 through a fifty-four pipe 54.

As shown in fig. 7, the air source heat pump which can absorb heat from outdoor air and can continuously supply heat and defrost is used in the occasion with heating demand by using the throttling device shown in fig. 6.

The whole equipment comprises the following components: a compression mechanism 1, a first four-way valve 70, a second four-way valve 80, a first outdoor heat exchanger 4, a second outdoor heat exchanger 5, a user heat exchanger 3, a seventh check valve 21, an eighth check valve 22, and a throttle device 100.

The air source heat pump can realize the functions of heating and heat absorption from outdoor air to alternatively defrost in the operation process.

The workflow under each function is as follows.

(1) Heating function

When the heat pump works normally, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers and are used as evaporators for absorbing heat from the environment; the user side heat exchanger 3 serves as a condenser for heating a user.

In operation, the throttle mechanism 6 operates normally for throttling, typically using an electronic expansion valve. The normally open solenoid valve 7 is opened.

In operation, a high pressure node 71 of first four-way valve 70 communicates with a first direction change node 72 of first four-way valve 70, and a second direction change node 74 of first four-way valve 70 communicates with a low pressure node 73 of first four-way valve 70. The high pressure node 81 of the second four-way valve 80 communicates with a first commutation node 82 of the second four-way valve 80 and a second commutation node 84 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant enters a sixty-th pipeline 60 and is divided into two paths; the first path sequentially passes through a sixteenth pipeline 60, a high-pressure node 71 of a first four-way valve 70, a first reversing node 72 of the first four-way valve 70, an inlet end of an eighth one-way valve 22 and an outlet end of the eighth one-way valve 22, and enters a fifty-first pipeline 51;

the second path sequentially passes through a sixteenth pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a first reversing node 82 of the second four-way valve 80, an inlet end of a seventh one-way valve 21 and an outlet end of the seventh one-way valve 21 and also enters a fifty-first pipeline 51;

two paths of refrigerant are mixed in a fifty-first pipeline 51, enter a user heat exchanger 3 and supply heat for a user, refrigerant gas in the refrigerant gas is changed into liquid after releasing heat, the refrigerant liquid passes through a third bypass pipe 55, a normally open electromagnetic valve 7, a fifty-fourth pipeline 54 and the inlet end of a throttling mechanism 6 after coming out of the user heat exchanger 3, enters the throttling mechanism 6 and is throttled, and the throttled refrigerant enters a fifty-eighth pipeline 58 and is divided into two paths after coming out of the outlet end of the throttling mechanism 6;

the first path sequentially passes through the inlet end of the second one-way valve 24, the outlet end of the second one-way valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, the sixty-seventh pipeline 67, the second reversing node 84 of the second four-way valve 80 and the low-pressure node 83 of the second four-way valve 80, and enters the sixty-fifth pipeline 65;

the second path sequentially passes through the inlet end of the first check valve 23, the outlet end of the first check valve 23, the first bypass pipe 56, the first outdoor heat exchanger 4, the sixty-fourth pipeline 64, the second reversing node 74 of the first four-way valve 70, the low-pressure node 73 of the first four-way valve 70 and also enters the sixty-fifth pipeline 65; the two paths are mixed in a sixty-five pipeline 65, then return to the inlet end of the compression mechanism 1, enter the compression mechanism 1 and are compressed again, and a cycle is completed.

(2) Function of absorbing heat from outdoor air and alternatively defrosting

When operating in this function, the normally open solenoid valve 7 is closed. The throttle mechanism 6 works normally and the user heat exchanger 3 does not work. The two groups of outdoor heat exchangers alternately defrost. The working processes are respectively as follows.

1) When the first outdoor heat exchanger 4 is defrosted, the second outdoor heat exchanger 5 operates normally to absorb heat from the outdoor air

At this time, the second four-way valve 80 does not operate and maintains the state during the heating function;

the first four-way valve 70 is switched, and the communication relationship among the four nodes is as follows: the high pressure node 71 of the first four way valve 70 communicates with the second commutation node 74 of the first four way valve 70 and the first commutation node 72 of the first four way valve 70 communicates with the low pressure node 73 of the first four way valve 70.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant sequentially passes through a sixty-th pipeline 60, a high-pressure node 71 of the first four-way valve 70, a second reversing node 74 of the first four-way valve 70, a sixty-fourth pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26, the outlet end of the fourth check valve 26, the inlet end of the throttling mechanism 6, the outlet end of the throttling mechanism 6, a fifty-eighth pipeline 58, the inlet end of the second check valve 24, the outlet end of the second check valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, a sixty-seventh pipeline 67, a second reversing node 84 of the second four-way valve 80 and a low-pressure node 83 of the second four-way valve 80, and enters the sixty-fifth pipeline 65; and then returning to the inlet end of the compression mechanism 1, entering the compression mechanism 1 and being compressed again, and completing one cycle.

2) When the second outdoor heat exchanger 5 is defrosted, the first outdoor heat exchanger 4 normally operates to absorb heat from the outdoor air

At this time, the first four-way valve 70 does not operate, and the state during the heating function is still maintained;

the second four-way valve 80 is switched, and the communication relationship among the four nodes is as follows: the high pressure node 81 of the second four-way valve 80 communicates with a second commutation node 84 of the second four-way valve 80 and the first commutation node 82 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant sequentially passes through a sixty-th pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a second reversing node 84 of the second four-way valve 80, a sixty-seventh pipeline 67, the second outdoor heat exchanger 5, a second bypass pipe 57, an inlet end of a third check valve 25, an outlet end of the third check valve 25, an inlet end of a throttling mechanism 6, an outlet end of a throttling mechanism 6, a fifty-eighth pipeline 58, an inlet end of a first check valve 23, an outlet end of a first check valve 23, a first bypass pipe 56, a first outdoor heat exchanger 4, a sixty-fourth pipeline 64, a second reversing node 74 of a first four-way valve 70 and a low-pressure node 73 of the first four-way valve 70, and enters a sixty-fifth pipeline 65; and then returning to the inlet end of the compression mechanism 1, entering the compression mechanism 1 and being compressed again, and completing one cycle.

The arrangement of fig. 7 can be further modified if it is necessary to add a reverse cycle hot air defrosting function for use in special situations (e.g., emergency defrosting).

The first improvement scheme is as follows: a normally closed solenoid valve 8 and a defrost capillary are added.

At this time, the connection mode of the normally closed electromagnetic valve 8 in the system is shown in fig. 2; the normally closed electromagnetic valve 8 is in a closed state under the heating and outdoor air heat absorption alternate defrosting functions; and is in an open state under the reverse circulation hot air defrosting function.

The defrosting capillary tube is used for throttling the refrigerant of the system under the reverse cycle hot gas defrosting function, and the connection relationship of the defrosting capillary tube in the system is as follows: defrosting capillary one end links to each other with normally open solenoid valve 7 one end, and the defrosting capillary other end links to each other with the normally open solenoid valve 7 other end.

At this time, the working flow of the heat pump system under the reverse cycle hot defrosting function is as follows:

in the working process, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers and are used as condensers, and frost on the outer surfaces of the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 is simultaneously melted by using heat absorbed from heating return water; the user side heat exchanger 3 is used as an evaporator and absorbs heat from the heating return water.

When the throttle mechanism 6 works, the throttle mechanism does not work; the defrost capillary tube is used for refrigerant throttling. The normally open solenoid valve 7 is closed and the normally closed solenoid valve 8 is opened.

In operation, the high pressure node 71 of the first four-way valve 70 communicates with the second commutation node 74 of the first four-way valve 70, and the first commutation node 72 of the first four-way valve 70 communicates with the low pressure node 73 of the first four-way valve 70. The high pressure node 81 of the second four-way valve 80 communicates with a second commutation node 84 of the second four-way valve 80 and the first commutation node 82 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant enters a sixty-th pipeline 60 and is divided into two paths; the first path sequentially passes through a sixty-th pipeline 60, a high-pressure node 71 of a first four-way valve 70, a second reversing node 74 of the first four-way valve 70, a sixty-fourth pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26 and the outlet end of the fourth check valve 26, and enters a fifty-fourth pipeline 54;

the second path sequentially passes through a sixteenth pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a second reversing node 84 of the second four-way valve 80, a sixteenth pipeline 67, the second outdoor heat exchanger 5, a second bypass pipe 57, an inlet end of a third check valve 25, an outlet end of the third check valve 25 and also enters a fifty-fourth pipeline 54; the two paths are mixed in a fifty-fourth pipeline 54 and then enter a defrosting capillary tube to be throttled into a low-temperature low-pressure gas-liquid two-phase mixture, and the low-temperature low-pressure gas-liquid two-phase mixture flows out of the defrosting capillary tube, sequentially passes through a third bypass pipe 55, the user heat exchanger 3, a fifty-first pipeline 51, a normally closed solenoid valve 8, a first reversing node 82 of a second four-way valve 80, a low-pressure node 83 of the second four-way valve 80 and a sixty-fifth pipeline 65, returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 and is compressed again, and a cycle is completed.

Similarly to embodiment 2, in order to avoid the action of the normally open solenoid valve 7 under the reverse cycle hot air defrosting function, a sixth check valve 29 can be added to the system, and the advantage of this is that: in the modification of the scheme shown in fig. 7, when the reverse-cycle hot air defrosting function is operated, the normally open solenoid valve 7 can be not operated, i.e. not electrified, and still keeps an open state.

After the sixth check valve 29 is added, the normally open electromagnetic valve 7 is electrified in a short time only when the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are alternately defrosted in winter, and is not electrified and does not work when working under the heating and reverse circulation hot air defrosting functions, so that the failure rate of the normally open electromagnetic valve 7 can be reduced, and the service life of the normally open electromagnetic valve is prolonged.

At this time, as shown in fig. 3, the connection relationship of the sixth check valve 29 in the system is as follows: the inlet end of the sixth check valve 29 is connected with the third bypass pipe 55 through the normally open electromagnetic valve 7, and the outlet end of the sixth check valve 29 is connected with the fifty-fourth pipeline 54. The connection relationship of the defrosting capillary in the system is as follows: one end of the defrosting capillary is connected to the third bypass pipe 55, and the other end of the defrosting capillary is connected to the fifty-fourth pipe 54.

The second improvement scheme is as follows: a normally closed solenoid valve 8 is added, and an electric ball valve is used for replacing the normally open solenoid valve 7, for example: the electric ball valve with three flowers can be fully opened and closed, plays the role of an electromagnetic valve, has the function of an electronic expansion valve and is used for throttling the refrigerant, and therefore can play the role of the electronic expansion valve under the function of reverse cycle hot defrosting and is used for throttling the refrigerant; and the electromagnetic valve 7 is normally opened under the functions of heating and heat absorption from outdoor air for alternate defrosting.

At this time, the connection mode of the normally closed electromagnetic valve 8 in the system is shown in fig. 2; the normally closed electromagnetic valve 8 is in a closed state under the heating and outdoor air heat absorption alternate defrosting functions; and is in an open state under the reverse circulation hot air defrosting function.

When the heat pump system works, the working process of the heat pump system under the reverse circulation hot defrosting function is as follows:

in the working process, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers and are used as condensers, and frost on the outer surfaces of the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 is simultaneously melted by using heat absorbed from heating return water; the user side heat exchanger 3 is used as an evaporator and absorbs heat from the heating return water.

When the throttle mechanism 6 works, the throttle mechanism does not work; the normally open electromagnetic valve 7 is used for throttling the refrigerant; the normally closed electromagnetic valve 8 is opened.

In operation, the high pressure node 71 of the first four-way valve 70 communicates with the second commutation node 74 of the first four-way valve 70, and the first commutation node 72 of the first four-way valve 70 communicates with the low pressure node 73 of the first four-way valve 70. The high pressure node 81 of the second four-way valve 80 communicates with a second commutation node 84 of the second four-way valve 80 and the first commutation node 82 of the second four-way valve 80 communicates with a low pressure node 83 of the second four-way valve 80.

The working process is as follows: after being discharged from the outlet end of the compression mechanism 1, the refrigerant enters a sixty-th pipeline 60 and is divided into two paths; the first path sequentially passes through a sixty-th pipeline 60, a high-pressure node 71 of a first four-way valve 70, a second reversing node 74 of the first four-way valve 70, a sixty-fourth pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26 and the outlet end of the fourth check valve 26, and enters a fifty-fourth pipeline 54;

the second path sequentially passes through a sixteenth pipeline 60, a fifty-ninth pipeline 59, a high-pressure node 81 of a second four-way valve 80, a second reversing node 84 of the second four-way valve 80, a sixteenth pipeline 67, the second outdoor heat exchanger 5, a second bypass pipe 57, an inlet end of a third check valve 25, an outlet end of the third check valve 25 and also enters a fifty-fourth pipeline 54; the two paths are mixed in a fifty-fourth pipeline 54 and then enter the normally open solenoid valve 7 to be throttled into a low-temperature low-pressure gas-liquid two-phase mixture, and the mixture sequentially passes through a third bypass pipe 55, the user heat exchanger 3, a fifty-first pipeline 51, the normally closed solenoid valve 8, a first reversing node 82 of a second four-way valve 80, a low-pressure node 83 of the second four-way valve 80 and a sixty-fifth pipeline 65 after coming out of the normally open solenoid valve 7, returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 and is compressed again, and a cycle is completed.

In all the embodiments of the present invention, any one of the first check valve 23, the second check valve 24, the third check valve 25, the fourth check valve 26, the fifth check valve 28, the sixth check valve 29, the seventh check valve 21 and the eighth check valve 22 can be replaced by any one of a solenoid valve, a throttle mechanism (e.g., an electronic expansion valve) having a shutoff function, and a flow rate adjusting mechanism. The shell of the one-way valve body is made of copper, brass or red copper.

The valve body shells of the normally open electromagnetic valve 7 and the normally closed electromagnetic valve 8 are also made of copper, brass or red copper.

In the solutions of all the above embodiments of the present invention, the throttling mechanism 6 and the auxiliary throttling mechanism 9 can adopt any one of the following throttling members:

1) an electronic expansion valve, the brand of which can be any one of sanhua, dun' an, Eegret, Danfoss, Kale, Emerson and the like;

2) a thermostatic expansion valve; the brand may be any one of sanhua, dun' an, japan aigret, denfoss, kara, emerson, etc.; a one-way thermostatic expansion valve may be employed;

3) other throttling members, or valve sets, may be unidirectional flow.

The economizer can adopt any one of a positive displacement heat exchanger, a plate heat exchanger, a shell and tube heat exchanger or a double-pipe heat exchanger, and is made of copper, copper alloy or stainless steel; or titanium metal.