阅读说明：本技术 空调系统及空调系统的控制方法 (Air conditioning system and control method thereof ) 是由 吴永和 黄昌成 柯彬彬 于 2020-11-24 设计创作，主要内容包括：本发明提供了一种空调系统及空调系统的控制方法,空调系统包括液泵管路和具有沿冷媒流动方向依次闭环连通的压缩机、冷凝器、膨胀阀和蒸发器的压缩机管路,液泵管路包括第一管路和第二管路,第一管路的一端与蒸发器和膨胀阀之间的管路连通,另一端与冷凝器和膨胀阀之间的管路连通；第一管路包括液泵和位于液泵和冷凝器之间的储液罐；第二管路的两端分别与蒸发器的第二端和冷凝器的第一端连通,以在液泵管路工作时对压缩机进行短路；当压缩机管路工作时,控制储液罐入口与压缩机管路接通,使压缩机管路中多余的冷媒进入储液罐内,以解决现有技术中复合空调系统因压缩机管路和液泵管路对制冷剂循环量需求不同而使空调系统出现多余液态制冷剂的问题。(The invention provides an air conditioning system and a control method thereof, wherein the air conditioning system comprises a liquid pump pipeline and a compressor pipeline which is provided with a compressor, a condenser, an expansion valve and an evaporator which are sequentially communicated in a closed loop manner along the flowing direction of a refrigerant, the liquid pump pipeline comprises a first pipeline and a second pipeline, one end of the first pipeline is communicated with the pipeline between the evaporator and the expansion valve, and the other end of the first pipeline is communicated with the pipeline between the condenser and the expansion valve; the first pipeline comprises a liquid pump and a liquid storage tank positioned between the liquid pump and the condenser; two ends of the second pipeline are respectively communicated with the second end of the evaporator and the first end of the condenser so as to short-circuit the compressor when the liquid pump pipeline works; when the compressor pipeline works, the inlet of the liquid storage tank is controlled to be communicated with the compressor pipeline, so that redundant refrigerants in the compressor pipeline enter the liquid storage tank, and the problem that the redundant liquid refrigerants of the air-conditioning system are caused due to different requirements of the compressor pipeline and the liquid pump pipeline on the circulating amount of the refrigerants in the prior art is solved.)

1. The utility model provides an air conditioning system, includes compressor pipeline and liquid pump pipeline, the compressor pipeline includes compressor (1), condenser (2), expansion valve (3) and evaporimeter (4) that follow the flow direction of refrigerant closed loop intercommunication in proper order, its characterized in that, the liquid pump pipeline includes:

a first line (101), a first end of the first line (101) being in communication with a line between a first end of the evaporator (4) and a second end of the expansion valve (3), a second end of the first line (101) being in communication with a line between a second end of the condenser (2) and a first end of the expansion valve (3); the first pipeline (101) comprises a liquid pump (5) and a liquid storage tank (6), and the liquid storage tank (6) is positioned between the liquid pump (5) and the condenser (2);

a second line (102), a first end of the second line (102) being in communication with a second end of the evaporator (4), a second end of the second line (102) being in communication with a first end of the condenser (2) for short-circuiting the compressor (1) through the second line (102) when the liquid pump line is in an operating mode;

when the compressor pipeline is in a working mode, the inlet of the liquid storage tank (6) is controlled to be communicated with the compressor pipeline, so that redundant refrigerant in the compressor pipeline is stored in the liquid storage tank (6).

2. Air conditioning system according to claim 1, characterized in that said first circuit (101) further comprises:

a first solenoid valve (7), the first solenoid valve (7) is located between the liquid storage tank (6) and the condenser (2).

3. Air conditioning system according to claim 1, characterized in that said first circuit (101) further comprises:

a second solenoid valve (8), the second solenoid valve (8) being located between the liquid pump (5) and the evaporator (4).

4. The air conditioning system of claim 1,

the evaporator (4) is internally provided with a device for detecting the evaporation temperature T in the evaporator (4)_eAn evaporation temperature detection means (15); and/or

The inlet of the compressor (1) is provided with a suction temperature T for detecting the compressor (1)_sThe intake air temperature detecting means (13).

5. The air conditioning system of claim 1,

the outlet of the compressor (1) is provided with a temperature T for detecting the exhaust gas temperature of the compressor (1)_dAn exhaust gas temperature detection means (14); and/or

The condenser (2) is internally provided with a condenser temperature T used for detecting the condenser (2)_cThe condensation temperature detection means (16).

6. Air conditioning system according to claim 1, wherein a differential pressure thermometer (11) is arranged between the top and the bottom of the liquid reservoir (6), said differential pressure thermometer (11) being connected to both the top and the bottom of the liquid reservoir (6) for detecting the liquid level differential pressure P of the refrigerant in the liquid reservoir (6) and the temperature Tg of the refrigerant in the liquid reservoir (6).

7. Air conditioning system according to claim 1, wherein the top and bottom of the liquid reservoir (6) are provided with a pressure sensor for detecting a liquid level pressure difference P of the refrigerant in the liquid reservoir (6); and a temperature sensor is arranged at the outlet or the inlet of the liquid storage tank (6) and is used for detecting the temperature Tg of the refrigerant in the liquid storage tank (6).

8. Air conditioning system according to claim 1, characterized in that the liquid pump line further comprises a first one-way valve (9), the first one-way valve (9) being arranged on the second line (102), the inlet of the first one-way valve (9) being connected to the outlet of the evaporator (4), the outlet of the first one-way valve (9) being connected to the inlet of the condenser (2).

9. Air conditioning system according to claim 1, characterized in that the compressor circuit further comprises a second one-way valve (10), the inlet of the second one-way valve (10) being connected to the outlet of the compressor (1), the outlet of the second one-way valve (10) being connected to the inlet of the condenser (2).

10. Air conditioning system according to claim 1, characterized in that both ends of the expansion valve (3) are provided with filters (12).

11. A control method of an air conditioning system, characterized in that the control method of an air conditioning system is applied to the air conditioning system of any one of claims 1 to 10, and the control method of an air conditioning system includes:

when the compressor pipeline is in a working mode and the opening of the expansion valve (3) is opened to a preset opening degree, detecting the evaporation temperature Te of the evaporator (4) and the suction temperature Ts of the compressor (1);

detecting a discharge temperature Td of said compressor (1) and a condensation temperature Tc of said condenser (2) when the difference between said evaporation temperature Te and said suction temperature Ts is less than a second preset temperature T2;

when the difference between the exhaust temperature Td and the condensation temperature Tc is less than a third preset temperature T3, controlling the connection between the inlet of the liquid storage tank (6) and the compressor pipeline so as to lead the redundant refrigerant in the compressor pipeline to enter the liquid storage tank (6);

wherein T3 > T2.

12. The control method of an air conditioning system as set forth in claim 11, wherein when communication is established between the inlet of the reservoir tank (6) and the compressor line, the control method of an air conditioning system further comprises:

detecting the liquid level pressure difference P in the liquid storage tank (6), and controlling the inlet of the liquid storage tank (6) to be disconnected from the compressor pipeline when the liquid level pressure difference P rises by a preset unit pressure difference delta P;

repeating the steps starting from detecting the discharge temperature Td of the compressor (1) and the condensation temperature Tc of the condenser (2) until the difference between said discharge temperature Td and said condensation temperature Tc is greater than a fourth preset temperature T4;

wherein T4 > T3.

13. Control method of an air conditioning system according to claim 11, characterized in that in detecting the evaporation temperature Te of the evaporator (4) and the suction temperature Ts of the compressor (1), when the difference between the evaporation temperature Te and the suction temperature Ts is greater than a first preset temperature T1, the connection between the outlet of the liquid storage tank (6) and the compressor circuit is controlled to supply refrigerant to the compressor circuit, wherein T3 > T1 > T2.

14. The control method of an air conditioning system as set forth in claim 13, wherein after the communication between the outlet of the reservoir tank (6) and the compressor line, the control method of an air conditioning system further comprises:

detecting the liquid level pressure difference P of the refrigerant in the liquid storage tank (6), closing the liquid pump (5) when the liquid level pressure difference P is reduced by a preset unit pressure difference delta P, and controlling the disconnection between the outlet of the liquid storage tank (6) and the compressor pipeline;

repeating the steps starting with detecting the evaporation temperature Te of the evaporator (4) and the suction temperature Ts of the compressor (1) until the difference between the evaporation temperature Te and the suction temperature Ts is less than the second preset temperature T2.

15. The control method of an air conditioning system according to claim 11, further comprising:

detecting a liquid level pressure difference P of the refrigerant in the liquid storage tank (6) when the difference between the evaporation temperature Te and the suction temperature Ts is less than a second preset temperature T2 and the difference between the discharge temperature Td and the condensation temperature Tc is greater than a fourth preset temperature T4;

when the liquid level pressure difference P is detected to be smaller than a first preset liquid level pressure difference P1, signaling that refrigerant leakage exists in the air conditioning system and sending a corresponding alarm signal;

wherein T4 > T3.

16. The control method of an air conditioning system according to claim 12, further comprising: detecting the temperature Tg of the refrigerant in the liquid storage tank (6), obtaining the density rho of the refrigerant in the liquid storage tank (6) according to the change of the detected temperature Tg of the refrigerant in the liquid storage tank (6), and selecting the preset unit pressure difference deltaP according to the density rho of the refrigerant in the liquid storage tank (6).

Technical Field

The invention relates to the technical field of air conditioners, in particular to an air conditioning system and a control method of the air conditioning system.

Background

The modern internet big data industry develops rapidly, along with the gradual increase of the scale of a data center, the calculation speed is gradually accelerated, and the heating power of IT equipment is also gradually increased, so that the load of a machine room air conditioner is increased, and the ratio of the energy consumption to the total energy consumption of the data center is nearly 35%.

In order to reduce the energy consumption of the air conditioner of the data center machine room, in the prior art, a liquid pump is adopted to replace a compressor to drive a refrigerant in an air conditioning system to circulate in winter, the refrigerant evaporates and absorbs heat in the machine room, the heat is brought to the outside and then is condensed and released, and the effect of reducing the indoor temperature is achieved. In addition, the mode of driving the refrigerant to cool naturally by the liquid pump has lower power compared with the mode of the vapor compression refrigeration cycle, so the aim of saving energy is also achieved.

However, since the operating principles, operating pressures, temperatures, and other conditions of the compressor and the liquid pump are completely different, the compressor and the liquid pump combined air conditioning system have different demands for the refrigerant circulation amount in the operating modes of the compressor and the liquid pump combined air conditioning system, and the refrigerant circulation amount required by the compressor is small and the refrigerant circulation amount required by the liquid pump is large. When the liquid pump mode is switched to the compressor mode, if the refrigerant perfusion amount of the air-conditioning system is not adjusted, the air-conditioning system will generate redundant liquid refrigerant when the compressor runs, so that the fatal liquid impact problem of the compressor is caused.

The liquid impact means that redundant liquid refrigerant is not fully evaporated and absorbs heat, and has no position capable of being stored, and the redundant liquid refrigerant is sucked into the compressor to impact a compression cylinder of the compressor, so that abnormal sound is generated, and the mechanical failure of the compressor is seriously caused.

Disclosure of Invention

The invention mainly aims to provide an air conditioning system and a control method of the air conditioning system, and aims to solve the problem that redundant liquid refrigerants are generated in the air conditioning system due to different requirements of a compressor working mode and a liquid pump working mode on the circulating quantity of the refrigerants in the composite air conditioning system in the prior art.

In order to achieve the above object, according to one aspect of the present invention, there is provided an air conditioning system including a compressor pipeline and a liquid pump pipeline, the compressor pipeline including a compressor, a condenser, an expansion valve, and an evaporator which are sequentially in closed-loop communication in a flow direction of a refrigerant, the liquid pump pipeline including: a first pipe, a first end of which communicates with a pipe between the first end of the evaporator and the second end of the expansion valve, and a second end of which communicates with a pipe between the second end of the condenser and the first end of the expansion valve; the first pipeline comprises a liquid pump and a liquid storage tank, and the liquid storage tank is positioned between the liquid pump and the condenser; the first end of the second pipeline is communicated with the second end of the evaporator, and the second end of the second pipeline is communicated with the first end of the condenser, so that when the liquid pump pipeline is in a working mode, the compressor is short-circuited through the second pipeline; when the compressor pipeline is in a working mode, the inlet of the liquid storage tank is controlled to be communicated with the compressor pipeline, so that redundant refrigerant in the compressor pipeline is stored in the liquid storage tank.

Further, the first pipeline further comprises: the first electromagnetic valve is positioned between the liquid storage tank and the condenser.

Further, the first pipeline further comprises: and the second electromagnetic valve is positioned between the liquid pump and the evaporator.

Further, the evaporator is internally provided with a device for detecting the evaporation temperature T in the evaporator_eThe evaporation temperature detection means of (3); and/or the inlet of the compressor is provided with a device for detecting the suction temperature T of the compressor_sThe intake air temperature detecting means of (1).

Further, an outlet of the compressor is provided with a temperature T for detecting the exhaust gas temperature of the compressor_dThe exhaust gas temperature detection means of (1); and/or the interior of the condenser is provided with a device for detecting the condensation temperature T in the condenser_cThe condensation temperature detection means of (1).

Further, a differential pressure thermometer is arranged between the top and the bottom of the liquid storage tank and connected with the top and the bottom of the liquid storage tank so as to be used for detecting the liquid level differential pressure P of the refrigerant in the liquid storage tank and the temperature Tg of the refrigerant in the liquid storage tank.

Furthermore, the top and the bottom of the liquid storage tank are respectively provided with a pressure sensor for detecting the liquid level pressure difference P of the refrigerant in the liquid storage tank; and a temperature sensor is arranged at the outlet or the inlet of the liquid storage tank and is used for detecting the temperature Tg of the refrigerant in the liquid storage tank.

Furthermore, the liquid pump pipeline also comprises a first one-way valve, the first one-way valve is arranged on the second pipeline, an inlet of the first one-way valve is connected with an outlet of the evaporator, and an outlet of the first one-way valve is connected with an inlet of the condenser.

Furthermore, the compressor pipeline also comprises a second one-way valve, an inlet of the second one-way valve is connected with an outlet of the compressor, and an outlet of the second one-way valve is connected with an inlet of the condenser.

Further, both ends of the expansion valve are provided with filters.

According to another aspect of the present invention, there is provided a control method of an air conditioning system, the control method of the air conditioning system being applied to the air conditioning system described above, the control method of the air conditioning system including: when the pipeline of the compressor is in a working mode and the opening of the expansion valve is opened to a preset opening degree, detecting the evaporation temperature Te of the evaporator and the suction temperature Ts of the compressor; detecting a discharge temperature Td of the compressor and a condensing temperature Tc of the condenser when a difference between the suction temperature Ts and the evaporating temperature Te is less than a second preset temperature T2; when the difference between the exhaust temperature Td and the condensation temperature Tc is less than a third preset temperature T3, controlling the connection between the inlet of the liquid storage tank and the compressor pipeline so as to enable redundant refrigerant in the compressor pipeline to enter the liquid storage tank; wherein T3 > T2.

Further, when the inlet of the liquid storage tank is communicated with the compressor pipeline, the control method of the air conditioning system further comprises the following steps: detecting the liquid level pressure difference P in the liquid storage tank, and controlling the inlet of the liquid storage tank to be disconnected from the compressor pipeline when the liquid level pressure difference P rises by a preset unit pressure difference delta P; repeating the steps starting with the detection of the discharge temperature Td of the compressor and the condensation temperature Tc of the condenser until the difference between the discharge temperature Td and the condensation temperature Tc is greater than a fourth preset temperature T4; wherein T4 > T3.

Further, when the evaporating temperature Te of the evaporator and the suction temperature Ts of the compressor are detected, and the difference between the suction temperature Ts and the evaporating temperature Te is greater than a first preset temperature T1, the connection between the outlet of the liquid storage tank and the compressor pipeline is controlled to provide refrigerant into the compressor pipeline.

Further, after the connection between the outlet of the liquid storage tank and the compressor pipeline, the control method of the air conditioning system further comprises the following steps: detecting the liquid level pressure difference P of the refrigerant in the liquid storage tank, and when the liquid level pressure difference P is reduced by a preset unit pressure difference delta P, closing the liquid pump and controlling the disconnection between the outlet of the liquid storage tank and the compressor pipeline; repeating the steps starting with detecting the evaporating temperature Te of the evaporator and the suction temperature Ts of the compressor until the difference between the suction temperature Ts and the evaporating temperature Te is less than a second preset temperature T2; wherein T3 > T1 > T2.

Further, the control method of the air conditioning system further includes: detecting a liquid level pressure difference P of refrigerant in the liquid storage tank when the difference between the suction temperature Ts and the evaporation temperature Te is less than a second preset temperature T2 and the difference between the exhaust temperature Td and the condensation temperature Tc is greater than a fourth preset temperature T4; when the liquid level pressure difference P is detected to be smaller than a first preset liquid level pressure difference P1, a signal that the refrigerant of the air conditioning system leaks is sent out, and a corresponding alarm signal is sent out; wherein T4 > T3.

Further, the control method of the air conditioning system further includes: and detecting the temperature Tg of the refrigerant in the liquid storage tank, obtaining the density rho of the refrigerant in the liquid storage tank according to the change of the detected temperature Tg of the refrigerant in the liquid storage tank, and selecting a preset unit pressure difference delta P according to the density rho of the refrigerant in the liquid storage tank.

The air conditioning system comprises a compressor pipeline and a liquid pump pipeline, wherein the compressor pipeline comprises a compressor, a condenser, an expansion valve and an evaporator which are sequentially communicated in a closed loop mode along the flowing direction of a refrigerant, the liquid pump pipeline comprises a main circulation pipeline and a bypass pipeline, the main circulation pipeline comprises a liquid pump, an evaporator, a condenser and a liquid storage tank which are sequentially arranged along the flowing direction of the refrigerant, the bypass pipeline comprises the expansion valve, the liquid pump pipeline is divided into the main circulation pipeline and the bypass pipeline through arranging a first pipeline, and the compressor is removed from the liquid pump pipeline through arranging a second pipeline in parallel connection with the compressor. When the compressor pipeline is in a working state, the inlet of the liquid storage tank is communicated with the compressor pipeline by controlling, redundant refrigerants in the compressor pipeline are stored in the liquid storage tank, the compressor pipeline and the liquid pump pipeline of the air-conditioning system can be rapidly and accurately stored or released by a refrigerant circulation quantity difference value when being switched, the refrigerant circulation quantity of the air-conditioning system is effectively adjusted, liquid impact of the compressor is prevented, the working reliability and the safety of the compressor working pipeline are improved, and the problem that the redundant liquid refrigerants occur in the air-conditioning system due to different requirements of the compressor working mode and the liquid pump working mode on the refrigerant circulation quantity of the composite air-conditioning system in the prior art is solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic structural view of an embodiment of an air conditioning system according to the present invention.

Wherein the figures include the following reference numerals:

1. a compressor; 2. a condenser; 3. an expansion valve; 4. an evaporator; 5. a liquid pump; 6. a liquid storage tank; 7. a first solenoid valve; 8. a second solenoid valve; 9. a first check valve; 10. a second one-way valve; 11. a differential pressure thermometer; 12. a filter; 13. an intake air temperature detection unit; 14. an exhaust gas temperature detection means; 15. an evaporation temperature detection section; 16. a condensation temperature detection means; 101. a first pipeline; 102. a second pipeline.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1, the present invention provides an air conditioning system, which includes a compressor pipeline and a liquid pump pipeline, wherein the compressor pipeline includes a compressor 1, a condenser 2, an expansion valve 3 and an evaporator 4 which are sequentially communicated in a closed loop along a flow direction of a refrigerant, and the liquid pump pipeline includes: a first pipe 101, a first end of the first pipe 101 being in communication with a pipe between a first end of the evaporator 4 and a second end of the expansion valve 3, a second end of the first pipe 101 being in communication with a pipe between a second end of the condenser 2 and a first end of the expansion valve 3; the first pipeline 101 comprises a liquid pump 5 and a liquid storage tank 6, and the liquid storage tank 6 is positioned between the liquid pump 5 and the condenser 2; a second pipeline 102, a first end of the second pipeline 102 is communicated with a second end of the evaporator 4, and a second end of the second pipeline 102 is communicated with a first end of the condenser 2, so that when the liquid pump pipeline is in a working mode, the compressor 1 is short-circuited through the second pipeline 102; when the compressor pipeline is in a working mode, the inlet of the liquid storage tank 6 is controlled to be communicated with the compressor pipeline, so that redundant refrigerant in the compressor pipeline is stored in the liquid storage tank 6.

The air conditioning system is a composite air conditioning system of a compressor and a liquid pump, and is provided with a compressor pipeline and a liquid pump pipeline, wherein the compressor pipeline comprises a compressor 1, a condenser 2, an expansion valve 3 and an evaporator 4 which are sequentially communicated in a closed loop mode along the flow direction of a refrigerant, the liquid pump pipeline comprises a main circulation pipeline and a bypass pipeline, the main circulation pipeline comprises a liquid pump 5, an evaporator 4, a condenser 2 and a liquid storage tank 6 which are sequentially arranged along the flow direction of the refrigerant, the bypass pipeline comprises the expansion valve 3, the liquid pump pipeline is divided into the main circulation pipeline and the bypass pipeline by arranging a first pipeline 101, and the compressor 1 is removed from the liquid pump pipeline by arranging a second pipeline 102 in parallel with the compressor. When the compressor pipeline is in a working state, the inlet of the liquid storage tank 6 is communicated with the compressor pipeline by controlling, redundant refrigerants in the compressor pipeline are stored in the liquid storage tank 6, the compressor pipeline and the liquid pump pipeline of the air-conditioning system can be rapidly and accurately stored or released when being switched, the refrigerant circulation quantity of the air-conditioning system is effectively adjusted, liquid impact of the compressor is prevented, the working reliability and safety of the compressor working pipeline are improved, and the problem that redundant liquid refrigerants occur in the air-conditioning system due to different requirements of the compressor working mode and the liquid pump working mode on the refrigerant circulation quantity of the composite air-conditioning system in the prior art is solved.

Wherein the compressor line and the liquid pump line share a condenser 2, an expansion valve 3 and an evaporator 4.

The first pipe 101 further includes: a first electromagnetic valve 7, the first electromagnetic valve 7 is positioned between the liquid storage tank 6 and the condenser 2.

A first electromagnetic valve 7 is arranged at the inlet of the liquid storage tank 6, and when the liquid pump pipeline is in a working state, the first electromagnetic valve 7 is always opened; when the compressor pipeline is in a working state and needs to store the refrigerant into the liquid storage tank 6, the first electromagnetic valve 7 is opened to recover the refrigerant; when the compressor circuit is in operation and there is no excess refrigerant, the first solenoid valve 7 is closed.

The first pipe 101 further includes: a second solenoid valve 8, the second solenoid valve 8 being located between the liquid pump 5 and the evaporator 4.

A second electromagnetic valve 8 is arranged at the outlet of the liquid pump 5, and when the liquid pump pipeline is in a working state, the second electromagnetic valve 8 is always opened; when the compressor pipeline is in a working state and needs to store the refrigerant into the liquid storage tank 6, the second electromagnetic valve 8 is closed to prevent the liquid pump 5 from being pushed to rotate due to the pressure difference of the refrigerant in the compressor pipeline, so that the refrigerant is prevented from returning to the liquid storage tank 6; when the compressor circuit is in operation and lacks refrigerant, the second solenoid valve 8 and the liquid pump are opened to supply refrigerant to the working circuit of the compressor circuit.

Preferably, an evaporation temperature detection means 15 for detecting the evaporation temperature Te inside the evaporator 4 is provided inside the evaporator 4; and/or the inlet of the compressor 1 is provided with a suction temperature detection means 13 for detecting the suction temperature Ts of the compressor 1.

Preferably, an outlet of the compressor 1 is provided with a discharge temperature detection means 14 for detecting a discharge temperature Td of the compressor 1; and/or a condensation temperature detecting means 16 for detecting the condensation temperature Tc in the condenser 2 is provided inside the condenser 2.

Specifically, the evaporation temperature detection means 15 is provided on the middle pipe line in the evaporator 4; the condensation temperature detection means 16 is provided on the middle pipe line inside the condenser 2. In fig. 1, the positions of the evaporation temperature detection unit 15 and the condensation temperature detection unit 16 are only schematic, and the specific positions are subject to the text description.

Specifically, each temperature detection member is a temperature sensor.

Optionally, a differential pressure thermometer 11 is disposed between the top and the bottom of the liquid storage tank 6, and the differential pressure thermometer 11 is connected to both the top and the bottom of the liquid storage tank 6 for detecting a liquid level differential pressure P of the refrigerant in the liquid storage tank 6 and a temperature Tg of the refrigerant in the liquid storage tank 6.

The differential pressure thermometer 11 is a composite differential pressure temperature detection device, which integrates a differential pressure detection component, a temperature detection component and the like on one detection device, and can simultaneously detect and display the liquid level differential pressure P of the refrigerant at the top and the bottom of the liquid storage tank 6 and the temperature Tg of the refrigerant.

Optionally, the top and the bottom of the liquid storage tank 6 are respectively provided with a pressure sensor for detecting a liquid level pressure difference P of the refrigerant in the liquid storage tank 6; a temperature sensor is provided at the outlet or inlet of the liquid storage tank 6 for detecting the temperature Tg of the refrigerant in the liquid storage tank 6.

The liquid pump pipeline further comprises a first one-way valve 9, the first one-way valve 9 is arranged on the second pipeline 102, an inlet of the first one-way valve 9 is connected with an outlet of the evaporator 4, and an outlet of the first one-way valve 9 is connected with an inlet of the condenser 2. Thus, when the liquid pump pipeline in the air conditioning system is in the working mode, the refrigerant flowing from the outlet of the evaporator 4 to the inlet of the condenser 2 can be ensured not to flow into the compressor 1 from the outlet of the compressor 1.

The compressor circuit further comprises a second one-way valve 10, the inlet of the second one-way valve 10 is connected with the outlet of the compressor 1, and the outlet of the second one-way valve 10 is connected with the inlet of the condenser 2. In this way, when the compressor pipeline in the air conditioning system is in the working mode, it can be ensured that the refrigerant flowing from the outlet of the compressor to the inlet of the condenser 2 does not flow into the evaporator 4.

Preferably, both ends of the expansion valve 3 are provided with filters 12. In this way, impurities in the refrigerant passing through the expansion valve 3 can be filtered.

When a liquid pump pipeline in the air-conditioning system is in a working mode, the first electromagnetic valve 7 and the second electromagnetic valve 8 are opened, the liquid pump 5 is opened, and the refrigerant is driven to be drawn out of the liquid storage tank 6, passes through the evaporator 4, the first one-way valve 9 and the condenser 2 of the main circulation pipeline and then returns to the liquid storage tank 6 to complete circulation. In addition, the expansion valve 3 is opened, and part of the refrigerant pumped by the liquid pump 5 directly returns to the liquid storage tank 6 through a bypass pipeline, thereby completing the circulation.

When a compressor pipeline in the air conditioning system is in a working mode, the first electromagnetic valve 7 and the second electromagnetic valve 8 are closed, and exhaust gas of the compressor 1 passes through the second one-way valve 10, the condenser 2, the expansion valve 3 and the evaporator 4 and then returns to the compressor 1 to complete a refrigeration cycle.

The invention also provides a control method of the air conditioning system, which is suitable for the air conditioning system and comprises the following steps: when the compressor pipeline is in a working mode and the opening of the expansion valve 3 is opened to a preset opening degree, detecting the evaporation temperature Te of the evaporator 4 and the suction temperature Ts of the compressor 1; detecting a discharge temperature Td of the compressor 1 and a condensing temperature Tc of the condenser 2 when a difference between the suction temperature Ts and the evaporating temperature Te is less than a second preset temperature T2; when the difference between the exhaust temperature Td and the condensation temperature Tc is less than a third preset temperature T3, controlling the connection between the inlet of the liquid storage tank 6 and the compressor pipeline so as to lead the redundant refrigerant in the compressor pipeline to enter the liquid storage tank 6; wherein T3 > T2.

When the compressor pipeline is in a working mode and runs to a stable state, and the opening degree of the expansion valve 3 is adjusted to a preset opening degree, the liquid pump 5, the first electromagnetic valve 7 and the second electromagnetic valve 8 are all in a closed state at the moment, and the evaporation temperature Te of the evaporator 4 and the suction temperature Ts of the compressor 1 are detected; when the suction superheat degree (Ts-Te) is less than a second preset temperature T2, if the circulation amount of the refrigerant is excessive, the discharge superheat degree of the compressor 1 is slightly small, and the discharge temperature Td of the compressor 1 and the condensation temperature Tc of the condenser 2 are detected; when the exhaust superheat degree (Td-Tc) < T3 is detected, the liquid pump 5 and the second electromagnetic valve 8 are kept inactive, the first electromagnetic valve 7 at the inlet of the liquid storage tank 6 is controlled to be opened, so that the inlet of the liquid storage tank 6 is communicated with the compressor pipeline, and redundant refrigerant in the compressor pipeline passes through the upper part of the liquid storage tank 6 and is gradually stored downwards into the liquid storage tank 6 under the action of pressure.

The third preset temperature T3 is a factory-set minimum exhaust superheat value, and the second preset temperature T2 is a factory-set proper suction superheat value.

Specifically, the evaporation temperature Te is a temperature at which the refrigerant is evaporated from a liquid state to a gaseous state in the evaporator 4 under a certain pressure, and the evaporation temperature Te is not constant along with a pressure loss caused by the refrigerant flowing in the evaporator 4, and the temperature at the middle pipeline in the evaporator 4 is taken as the evaporation temperature Te; the condensing temperature Tc is a saturated temperature at which the refrigerant is condensed from a gaseous state to a liquid state in the condenser 2 under a certain pressure, and is not constant along with a pressure loss caused by the flow of the refrigerant in the condenser 2, and the temperature at the middle pipeline in the condenser 2 is taken as the condensing temperature Tc.

Specifically, when the inlet of the liquid storage tank 6 is communicated with the compressor pipeline, the control method of the air conditioning system further comprises the following steps: detecting the liquid level pressure difference P in the liquid storage tank 6, and controlling the disconnection between the inlet of the liquid storage tank 6 and the compressor pipeline when the liquid level pressure difference P rises by a preset unit pressure difference delta P; repeating the steps starting with the detection of the discharge temperature Td of the compressor 1 and the condensation temperature Tc of the condenser 2 until the difference between the discharge temperature Td and the condensation temperature Tc is greater than a fourth preset temperature T4; wherein T4 > T3.

When the liquid level pressure difference P is detected to be increased by the preset unit pressure difference delta P, closing a first electromagnetic valve 7 at the inlet of the liquid storage tank 6 so as to disconnect the inlet of the liquid storage tank 6 from the compressor pipeline; the steps starting from the detection of the exhaust temperature Td of the compressor 1 and the condensation temperature Tc of the condenser 2 are repeated until the exhaust superheat degree (Td-Tc) is greater than a fourth preset temperature T4, so that the recovery of excessive refrigerant in the compressor pipeline is completed, the refrigeration efficiency of the compressor pipeline is improved, and the liquid impact caused by long-time liquid-carrying operation of the compressor pipeline is prevented.

The fourth preset temperature T4 is a factory-set value of the exhaust superheat degree.

Specifically, when the difference between the suction temperature Ts and the evaporation temperature Te is greater than a first preset temperature T1 when detecting the evaporation temperature Te of the evaporator 4 and the suction temperature Ts of the compressor 1, the connection between the outlet of the liquid storage tank 6 and the compressor pipeline is controlled to provide refrigerant into the compressor pipeline, wherein T3 > T1 > T2.

When the compressor pipeline is in a working mode and runs to a stable state, and the opening degree of the expansion valve 3 is adjusted to a preset opening degree, at the moment, the liquid pump 5, the first electromagnetic valve 7 and the second electromagnetic valve 8 are all in a closed state, if the circulating amount of the refrigerant is too small at the moment, the suction superheat degree of the compressor 1 is large, and the evaporation temperature Te of the evaporator 4 and the suction temperature Ts of the compressor 1 are detected; when the suction superheat degree (Ts-Te) is detected to be more than T1, the first electromagnetic valve 7 is controlled to be kept closed, the second electromagnetic valve 8 and the liquid pump 5 are controlled to be opened, so that the inlet of the liquid storage tank 6 is disconnected with the compressor pipeline, and the outlet of the liquid storage tank 6 is connected with the compressor pipeline.

The first preset temperature T1 is a factory-set maximum superheat value of air intake.

Specifically, after the connection between the outlet of the liquid storage tank 6 and the compressor pipeline, the control method of the air conditioning system further comprises the following steps: detecting the liquid level pressure difference P of the refrigerant in the liquid storage tank 6, and when the liquid level pressure difference P is reduced by a preset unit pressure difference delta P, closing the liquid pump 5 and controlling the disconnection between the outlet of the liquid storage tank 6 and the compressor pipeline; the steps starting from detecting the evaporation temperature Te of the evaporator 4 and the suction temperature Ts of the compressor 1 are repeated until the difference between the suction temperature Ts and the evaporation temperature Te is less than a second preset temperature T2.

When the detected liquid level height difference P is reduced by the preset unit pressure difference delta P, the second electromagnetic valve 8 and the liquid pump 5 are closed, so that the outlet of the liquid storage tank 6 is disconnected from the compressor pipeline, and the refrigerant is stopped being conveyed to the compressor pipeline; and repeating the steps starting from the detection of the evaporation temperature Te of the evaporator 4 and the suction temperature Ts of the compressor 1 until the suction superheat degree (Ts-Te) is less than T2, finishing the action of filling the refrigerant into the compressor pipeline and improving the refrigeration efficiency of the compressor pipeline.

Specifically, the control method of the air conditioning system further includes: detecting a liquid level pressure difference P of the refrigerant in the liquid storage tank 6 when the difference between the suction temperature Ts and the evaporation temperature Te is less than a second preset temperature T2 and the difference between the discharge temperature Td and the condensation temperature Tc is greater than a fourth preset temperature T4; when the liquid level pressure difference P is detected to be smaller than a first preset liquid level pressure difference P1, a signal that the refrigerant of the air conditioning system leaks is sent out, and a corresponding alarm signal is sent out; wherein T4 > T3.

When the compressor pipeline is in a working state, and each parameter is in a normal range, the refrigerant amount in the liquid pump 5 and the liquid storage tank 6 and the refrigerant circulation amount in the external compressor pipeline are in a factory setting state, if the liquid level pressure difference P is detected to be less than a first preset liquid level pressure difference P1, the problem of refrigerant leakage in the compressor pipeline can be judged, and the signal needs to be fed back to the controller and a corresponding alarm signal is displayed.

The first preset liquid level pressure difference P1 is a standard reference pressure difference set by a factory, and the controller can select different first preset liquid level pressure differences P1 according to the change of the temperature Tg of the refrigerant in the liquid storage tank 6, so as to ensure that each first preset liquid level pressure difference P1 corresponds to the refrigerant with the same quality.

Specifically, the control method of the air conditioning system further includes: the temperature Tg of the refrigerant in the liquid storage tank 6 is detected, the density rho of the refrigerant in the liquid storage tank 6 is obtained according to the change of the detected temperature Tg of the refrigerant in the liquid storage tank 6, and the preset unit pressure difference delta P is selected according to the density rho of the refrigerant in the liquid storage tank 6.

The preset unit pressure difference delta P is also a factory-set value and represents the unit pressure difference amount of the change of the refrigerant in the liquid storage tank 6, the factory-set preset unit pressure difference delta P has a plurality of different values so as to correspond to the densities rho of the refrigerant in different liquid storage tanks 6, the controller can obtain the density rho of the refrigerant in the liquid storage tank 6 according to the change of the temperature Tg of the refrigerant in the liquid storage tank 6, and therefore different preset unit pressure difference delta P values are selected to ensure that each preset unit pressure difference delta P corresponds to the refrigerant with the same quality, and the quality of the change of the refrigerant in the liquid storage tank 6 is the same each time.

The density rho of the saturated liquid refrigerant changes along with the change of the temperature Tg of the refrigerant, the density rho of the saturated liquid refrigerant at the moment can be obtained according to the measured temperature Tg of the refrigerant in the liquid storage tank 6, and the liquid level height delta h of the refrigerant in the liquid storage tank 6 can be calculated by combining the measured liquid level pressure difference P of the refrigerant in the liquid storage tank 6 and a formula delta h which is P/(rhog); wherein g is the acceleration of gravity.

The actual temperature of the working medium at the air suction port and the air discharge port of the compressor is higher than the saturation temperature corresponding to the actual pressure, the air suction temperature Ts of the compressor 1 is higher than the evaporation temperature Te of the refrigerant in the evaporator 4, and the air discharge temperature Td of the compressor 1 is higher than the condensation temperature Tc of the refrigerant in the condenser 2.

Suction superheat is equal to the suction temperature Ts of the compressor 1 — the evaporation temperature Te of the refrigerant in the evaporator 4; the discharge superheat degree is equal to the discharge temperature Td of the compressor 1 — the condensation temperature Tc of the refrigerant in the condenser 2.

If the circulation amount of the refrigerant is too large, the degree of superheat of the discharge gas of the compressor 1 is small; if the circulation amount of the refrigerant is too small, the suction superheat degree of the compressor 1 becomes excessively large; the reason for ensuring a certain degree of superheat is to keep the compressor 1 in a good working condition.

The invention calculates and judges whether the refrigerant circulation quantity in the compressor pipeline is in a proper value or not through parameters such as the suction temperature and the exhaust temperature at the inlet and the outlet of the compressor 1, the evaporation temperature of the evaporator 4, the condensation temperature of the condenser 2 and the like, thereby judging whether the liquid pump 5 and the liquid storage tank 6 need to recover or pour the refrigerant or not.

In addition, the invention calculates the liquid level height in the liquid storage tank 6 through the pressure difference value of the top and the bottom of the liquid storage tank 6 and the temperature of the refrigerant in the liquid storage tank 6, uses the liquid level height as the main parameter of the refrigerant amount, and the auxiliary liquid pump 5 and the liquid storage tank 6 recover or fill the refrigerant of the air conditioning system, and judges whether the storage or the release of the refrigerant is accurate by using the operation parameters of the air conditioning system, so as to ensure the optimal refrigerant circulation amount required by the work of the air conditioning system, thereby realizing the high-efficiency and reliable operation of the air conditioning system.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

the air conditioning system is a composite air conditioning system of a compressor and a liquid pump, and is provided with a compressor pipeline and a liquid pump pipeline, wherein the compressor pipeline comprises a compressor 1, a condenser 2, an expansion valve 3 and an evaporator 4 which are sequentially communicated in a closed loop mode along the flow direction of a refrigerant, the liquid pump pipeline comprises a main circulation pipeline and a bypass pipeline, the main circulation pipeline comprises a liquid pump 5, an evaporator 4, a condenser 2 and a liquid storage tank 6 which are sequentially arranged along the flow direction of the refrigerant, the bypass pipeline comprises the expansion valve 3, the liquid pump pipeline is divided into the main circulation pipeline and the bypass pipeline by arranging a first pipeline 101, and the compressor 1 is removed from the liquid pump pipeline by arranging a second pipeline 102 in parallel with the compressor. When the air-conditioning system is switched to the compressor pipeline from the liquid pump pipeline, the inlet of the liquid storage tank 6 is communicated with the compressor pipeline by controlling, so that redundant refrigerants in the compressor pipeline are stored in the liquid storage tank 6, the compressor pipeline and the liquid pump pipeline of the air-conditioning system can be rapidly and accurately stored or released according to a refrigerant circulation quantity difference value when being switched, the refrigerant circulation quantity of the air-conditioning system is effectively adjusted, liquid impact of the compressor is prevented, the working reliability and safety of the working pipeline of the compressor are improved, and the problem that redundant liquid refrigerants occur in the air-conditioning system due to different requirements of a compressor working mode and a liquid pump working mode on the refrigerant circulation quantity of the composite air-conditioning system in the prior art is solved.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.