阅读说明：本技术 一种热交换装置及中央空调 (Heat exchange device and central air conditioner ) 是由 张立杰 张梅珊 于 2020-05-13 设计创作，主要内容包括：本发明实施例涉及一种热交换装置及中央空调,包括塔体、风机、湿帘、换热器和喷淋系统；所述塔体设置有进风口和出风口,所述进风口用于空气进入所述塔体,所述出风口用于空气排出所述塔体；所述风机用于经出风口排出所述塔体内的空气,以形成气流；沿所述气流的流动方向依次设置有湿帘和换热器,所述湿帘能够与所述气流进行热交换,所述换热器能够与中央空调换热介质循环系统连通,以使中央空调换热介质经所述换热器与所述气流进行热交换；所述喷淋系统能够将湿帘换热介质喷淋在所述湿帘上。该热交换装置可用于实现多种功能,换热效率高。(The embodiment of the invention relates to a heat exchange device and a central air conditioner, which comprise a tower body, a fan, a wet curtain, a heat exchanger and a spraying system, wherein the fan is arranged on the tower body; the tower body is provided with an air inlet and an air outlet, the air inlet is used for air to enter the tower body, and the air outlet is used for air to be discharged out of the tower body; the fan is used for discharging air in the tower body through the air outlet so as to form airflow; a wet curtain and a heat exchanger are sequentially arranged along the flowing direction of the airflow, the wet curtain can exchange heat with the airflow, and the heat exchanger can be communicated with a central air conditioner heat exchange medium circulating system so as to enable a central air conditioner heat exchange medium to exchange heat with the airflow through the heat exchanger; the spraying system can spray the wet curtain heat exchange medium on the wet curtain. The heat exchange device can be used for realizing multiple functions and has high heat exchange efficiency.)

1. A heat exchange device is characterized by comprising a tower body, a fan, a wet curtain, a heat exchanger and a spraying system; the tower body is provided with an air inlet and an air outlet, the air inlet is used for air to enter the tower body, and the air outlet is used for air to be discharged out of the tower body; the fan is used for discharging air in the tower body through the air outlet so as to form airflow; a wet curtain and a heat exchanger are sequentially arranged along the flowing direction of the airflow, the wet curtain can exchange heat with the airflow, and the heat exchanger can be communicated with a central air conditioner heat exchange medium circulating system so as to enable a central air conditioner heat exchange medium to exchange heat with the airflow through the heat exchanger; the spraying system can spray the wet curtain heat exchange medium on the wet curtain.

2. The heat exchange apparatus as claimed in claim 1, wherein the tower body includes a side wall and an upper cover, the side wall having an air inlet and the upper cover having an air outlet.

3. The heat exchange device of claim 1, wherein the heat exchanger is a surface cooler.

4. A heat exchange unit according to claim 3, wherein the surface cooler comprises a heat exchange tube and a plurality of fins, adjacent fins of the plurality of fins having a pitch of above 2.2mm, preferably above 5mm, preferably above 6mm, preferably above 7mm, preferably above 8 mm; preferably below 9 mm; preferably, the distance between adjacent fins in the plurality of fins is 2.2mm-9 mm; preferably 4-9 mm; more preferably, the spacing between adjacent fins in the plurality of fins is 6-9 mm.

5. The heat exchange device of claim 1, wherein the wet curtain heat exchange medium is water.

6. The heat exchange device according to claim 1, wherein the central air-conditioning heat exchange medium circulating system is a central air-conditioning cooling liquid circulating system, and the heat exchanger is communicated with the central air-conditioning cooling liquid circulating system; alternatively, the first and second electrodes may be,

the central air-conditioning heat exchange medium circulating system is a central air-conditioning refrigerating fluid circulating system, and the heat exchanger is communicated with the central air-conditioning refrigerating fluid circulating system; alternatively, the first and second electrodes may be,

the central air-conditioning heat exchange medium circulating system is a central air-conditioning heat preservation liquid circulating system, and the heat exchanger is communicated with the central air-conditioning heat preservation liquid circulating system.

7. The heat exchange device of claim 1, further comprising a sump for collecting the wet curtain heat exchange medium that flows down the wet curtain surface.

8. The heat exchange device according to claim 1, wherein the wet curtain is disposed at the air inlet, the heat exchanger is disposed inside the wet curtain, and air enters the tower body through the wet curtain and exchanges heat with the heat exchanger.

9. A heat exchange unit according to claim 1, wherein the tower is tetrahedral and is bounded by two oppositely disposed wet curtains and two oppositely disposed side walls.

10. A central air conditioner, characterized in that the central air conditioner comprises the heat exchange device as claimed in any one of claims 1 to 8 and a central air conditioner heat exchange medium circulating system, wherein the heat exchanger of the heat exchange device is communicated with the central air conditioner heat exchange medium circulating system; the central air-conditioning heat exchange medium circulating system is a central air-conditioning refrigerating fluid circulating system or a central air-conditioning cooling fluid circulating system or a central air-conditioning heat preservation fluid circulating system; preferably, the central air-conditioning refrigerating fluid is chilled water, the central air-conditioning cooling fluid is cooling water, and the central air-conditioning heat preservation fluid is a low-enthalpy salt solution or an antifreeze.

Technical Field

The invention belongs to the technical field of air conditioners, and particularly relates to a heat exchange device and a central air conditioner.

Background

The central air conditioner comprises four parts, namely a compressor, a condenser, a throttling device and an evaporator, wherein a refrigerant circulates in the four parts in sequence. The compressor compresses low-temperature low-pressure refrigerant gas to output high-temperature high-pressure refrigerant gas; the high-temperature high-pressure refrigerant gas flows through the condenser to give out heat to cooling water, high-temperature high-pressure refrigerant liquid is output after condensation, and the heat given out in the condensation process is carried to an outdoor cooling tower through a cooling water system and is discharged; the high-temperature high-pressure refrigerant liquid continuously flows and is converted into low-temperature low-pressure refrigerant liquid through the throttling device; the low-temperature low-pressure refrigerant liquid flows through the evaporator, absorbs heat from the environment, is converted into low-temperature low-pressure refrigerant gas, and then flows into the compressor, the two ends of the evaporator are connected with a chilled water circulating system, and the temperature of the chilled water is reduced by the evaporation and heat absorption of the refrigerant; the low-temperature chilled water is conveyed to a user end, and then is subjected to heat exchange through the fan coil to blow out cold air.

Cooling towers are used to cool cooling water, and cooling towers in the prior art generally comprise a tower body, a spraying device and a fan. When the cooling tower cools the cooling water, the cooling water is firstly sprayed to the surface of the heat dissipation device through the spraying device to be contacted with the cold air flowing through the surface of the heat dissipation device, sensible heat exchange effect is generated between the cooling water and the cold air, meanwhile, part of the cooling water is evaporated, and evaporation latent heat is also discharged to the air, so that the cooling water is cooled after the heat exchange, falls into the water tank, is conveyed to the central air conditioner through the water pump, and is used for absorbing heat released by a refrigerant at the condenser.

Disclosure of Invention

In order to solve at least one of the above technical problems, embodiments of the present invention provide a heat exchange device and a central air conditioner.

According to a first aspect of the invention, an embodiment of the invention provides a heat exchange device.

A heat exchange device comprises a tower body, a fan, a wet curtain, a heat exchanger and a spraying system; the tower body is provided with an air inlet and an air outlet, the air inlet is used for air to enter the tower body, and the air outlet is used for air to be discharged out of the tower body; the fan is used for discharging air in the tower body through the air outlet so as to form airflow; a wet curtain and a heat exchanger are sequentially arranged along the flowing direction of the airflow, the wet curtain can exchange heat with the airflow, and the heat exchanger can be communicated with a central air conditioner heat exchange medium circulating system so as to enable a central air conditioner heat exchange medium to exchange heat with the airflow through the heat exchanger; the spraying system can spray the wet curtain heat exchange medium on the wet curtain.

Further, the tower body includes lateral wall and upper cover, be provided with the air intake on the lateral wall, the upper cover is provided with the air outlet.

Further, the heat exchanger is a surface cooler.

Further, the surface cooler comprises a heat exchange tube and a plurality of fins, and the distance between adjacent fins in the plurality of fins is more than 2.2 mm.

Further, the spacing between adjacent fins in the plurality of fins is more than 5 mm.

Further, the pitch of adjacent fins among the plurality of fins is 6mm or more.

Further, the pitch between adjacent fins among the plurality of fins is 7mm or more.

Further, the spacing between adjacent fins in the plurality of fins is more than 8 mm.

Further, the spacing between adjacent fins among the plurality of fins is 9mm or less.

Further, the distance between adjacent fins in the plurality of fins is 2.2mm-9 mm.

Further, the distance between adjacent fins in the plurality of fins is 4-9 mm.

Further, the distance between adjacent fins in the plurality of fins is 6-9 mm.

Further, the wet curtain heat exchange medium is water.

Further, the central air-conditioning heat exchange medium circulating system is a central air-conditioning cooling liquid circulating system, and the heat exchanger is communicated with the central air-conditioning cooling liquid circulating system; alternatively, the first and second electrodes may be,

the central air-conditioning heat exchange medium circulating system is a central air-conditioning refrigerating fluid circulating system, and the heat exchanger is communicated with the central air-conditioning refrigerating fluid circulating system; alternatively, the first and second electrodes may be,

the central air-conditioning heat exchange medium circulating system is a central air-conditioning heat preservation liquid circulating system, and the heat exchanger is communicated with the central air-conditioning heat preservation liquid circulating system.

Furthermore, the heat exchange device also comprises a liquid collecting tank, and the liquid collecting tank is used for collecting the wet curtain heat exchange medium flowing down from the surface of the wet curtain.

Further, wet curtain sets up air intake department, the heat exchanger sets up the inboard of wet curtain, the air carries out the heat exchange with the heat exchanger after wet curtain gets into the tower body.

Furthermore, the tower body is tetrahedron and is enclosed by two wet curtains which are oppositely arranged and two side walls which are oppositely arranged.

According to a second aspect of the present invention, an embodiment of the present invention further provides a central air conditioner.

A central air conditioner comprises one of the heat exchange devices and a central air conditioner heat exchange medium circulating system, wherein a heat exchanger of the heat exchange device is communicated with the central air conditioner heat exchange medium circulating system; the central air-conditioning heat exchange medium circulating system is a central air-conditioning refrigerating fluid circulating system or a central air-conditioning cooling fluid circulating system or a central air-conditioning heat preservation fluid circulating system.

Further, the refrigerating fluid of the central air conditioner is chilled water, the cooling fluid of the central air conditioner is cooling water, and the heat preservation fluid of the central air conditioner is low-enthalpy salt solution or antifreeze fluid.

The embodiment of the invention has the following beneficial effects: the heat exchange device provided by the embodiment of the invention can selectively realize multiple functions according to requirements: the cooling tower can be used as a cooling tower in summer to cool cooling water of a central air conditioner, and has high heat exchange efficiency and high energy efficiency ratio; the heat source can be used in cold seasons, and heat and hot water can be supplied by absorbing heat from the environment; the cold source can be independently used in spring and autumn and other suitable seasons, the operation of a central air conditioning unit is not needed, and the energy consumption is reduced. In addition, the spray water in the cooling tower in the embodiment of the invention is not communicated with the condenser of the central air conditioner, the heat exchange medium (cooling liquid/refrigerating liquid/heat preservation liquid) of the central air conditioner exchanges heat with the air in the cooling tower through the heat exchanger, and the heat exchange medium of the central air conditioner circulates in a closed manner, so that the problem that the cooling water in the cooling tower in the prior art is polluted and then flows into the central air conditioning system, and the risk is brought to the central air conditioning system is avoided.

Drawings

Fig. 1 is an assembly schematic diagram of a heat exchange device according to an embodiment of the present invention.

Fig. 2 is an exploded view of a heat exchanger according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a heat exchange device according to an embodiment of the present invention, which is used as a cooling tower of a central air conditioning system or as a cooling source.

Fig. 4 is a schematic view of a heat exchange device according to an embodiment of the present invention as a heat source.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings. Those skilled in the art will appreciate that the present invention is not limited to the drawings and the following examples.

Heat exchange device

According to a first aspect of the present invention, an embodiment of the present invention provides a heat exchange apparatus 100, which is used for a central air conditioner, is connected to a central air conditioning unit M, and can be used as a cooling tower, a cold source or a heat source of the central air conditioner, and includes a tower body 1, a wet curtain 2, a fan 3, a heat exchanger 4, a spraying system 5 and a collecting tank (not shown in the figure).

The tower body 1 is provided with an air inlet 11, air enters the tower body 1 from the air inlet 11, an air outlet 12 is arranged above the tower body 1, and the air is discharged out of the tower body 1 from the air outlet 12.

The fan 3 is configured to exhaust air in the tower body 1 through the air outlet 12, for example, the fan 3 may be disposed at the air outlet 12. Under the action of the fan 3, air outside the tower body 1 enters from the air inlet 11 and is discharged from the air outlet 12 to form airflow.

The wet curtain 2 and the heat exchanger 4 are arranged in sequence along the flowing direction of the air flow, and other components can be included between the wet curtain 2 and the heat exchanger 4, which is not limited by the invention. Through this arrangement, most of the air current will contact with the heat exchanger 4 after passing through the wet curtain 2 earlier, and from this, the air current exchanges heat with the wet curtain 2 earlier, exchanges heat with the heat exchanger 4 again.

The wet curtain 2 is capable of exchanging heat with the air flow. In one embodiment, air enters the tower 1 via a wet curtain 2.

Referring to fig. 1 and 2, in one embodiment, the tower body 1 includes a side wall 13 and an upper cover 14, an air inlet 11 is disposed on the side wall 13, the wet curtain 2 is disposed at the air inlet 11, an access door is further disposed on the side wall 13, and an air outlet 12 is disposed on the upper cover 14. The tower body 1 is, for example, tetrahedral and is enclosed by two wet curtains 2 arranged opposite to each other and two side walls 13 arranged opposite to each other. The tower body 1 can also adopt other structures, such as a cylinder; the size, shape and the like of the wet curtain can be determined according to actual needs, and after reading the invention, a person skilled in the art can easily determine the structures of the tower body and the wet curtain according to the actual needs, and the invention is not limited to this.

In one embodiment, the heat exchanger 4 is disposed inside the wet curtain 2, and air enters the tower body 1 through the wet curtain 2 and then exchanges heat with the heat exchanger 4. For example, the heat exchanger 4 is disposed adjacent to the wet curtain 2, and is arranged side by side with the wet curtain 2.

The heat exchanger 4 can be communicated with a central air conditioner heat exchange medium circulating system and is used for circulating a central air conditioner heat exchange medium so as to enable the central air conditioner heat exchange medium to exchange heat with air in the heat exchange device. The central air-conditioning heat exchange medium circulating system is a central air-conditioning refrigerating fluid circulating system or a central air-conditioning cooling fluid circulating system or a central air-conditioning heat preservation fluid circulating system.

In some working conditions, the heat exchanger 4 is communicated with a central air-conditioning coolant circulation system, at this time, the central air-conditioning heat exchange medium flowing into the heat exchanger 4 is a central air-conditioning coolant, such as cooling water, and the coolant is used for taking away heat released during condensation of a refrigerant from a condenser L of the central air-conditioning unit M.

In some working conditions, the heat exchanger 4 is communicated with a central air-conditioning refrigerant fluid circulation system, at this time, the central air-conditioning heat exchange medium flowing into the heat exchanger 4 is a central air-conditioning refrigerant fluid, such as chilled water, and the refrigerant fluid is used for refrigerating a user side.

When the central air conditioning unit M is used as a heat pump unit to perform heating, the heat exchanger 4 is communicated with a central air conditioning heat preservation solution circulation system, at this time, a central air conditioning heat exchange medium flowing into the heat exchanger 4 is a central air conditioning heat preservation solution, such as a low enthalpy salt solution or an antifreeze solution, and the heat preservation solution is used for providing heat required by the evaporation of a refrigerant from an evaporator of the central air conditioning.

Under different working conditions, the heat exchanger 4 is communicated with different central air-conditioning heat exchange medium circulating systems, so that the functions of a cooling tower, a cold source or a heat source are achieved. Those skilled in the art can easily select a suitable heat exchange medium of the central air conditioner, such as water, oil, antifreeze, low enthalpy salt solution or other suitable liquid, under different working conditions according to the disclosure of the present invention, which is not limited in this respect.

Preferably, the heat exchanger 4 is a surface cooler. The surface cooler 4 includes a heat exchange tube and a plurality of fins. The composition and structure of the surface cooler can be clearly known by those skilled in the art according to the prior art, and can be implemented according to actual needs.

More preferably, the pitch between adjacent fins among the plurality of fins is 2.2mm or more, still more preferably 5mm or more, still more preferably 6mm or more, still more preferably 7mm or more, and still more preferably 8mm or more. The spacing between adjacent fins in the plurality of fins is less than 9 mm. The spacing between adjacent fins in the plurality of fins is preferably 2.2mm to 9mm, for example 2.2mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9 mm. When the distance between the adjacent fins is larger, for example, more than 6mm, the heat exchange device can be used as a heat source in cold seasons of cold regions without frosting, the distance is larger than that of the prior art, by adopting the larger distance, when the heat exchange device of the embodiment of the invention is used as a heat source in cold seasons of cold regions, under the action of the fan, the larger distance can enable solid ice crystals condensed from water vapor in the air to pass through gaps of the fins and not to be attached to the surface of the surface cooler, so that the surface problem of the surface cooler located outdoors can be avoided, a defrosting step is not needed during use, the central air conditioning system can rapidly heat, energy is saved, and the skilled person knows that even if the surface cooler located indoors has frosting easily on the surface in cold seasons, and the surface cooler is frosting easily used outdoors, however, the inventors have unexpectedly found that, because the wind generated by the fan of the heat exchange device is large, the frosting problem can be solved by only using the adjacent fins with the large spacing without complex design, so that the heat exchange device of the embodiment can be used as a heat source, and the influence of the spacing on the heat exchange efficiency is negligible. As will be understood by those skilled in the art based on the disclosure of the present specification, the distance between adjacent fins may be reasonably selected according to the climate of the area where the heat exchanger according to the embodiment of the present invention is installed and the power of the fan, in cold seasons, the area with higher air temperature may be lower than 6mm, and in areas with lower air temperature, the distance may be increased appropriately, for example, more than 6mm, or even 9 mm; if the heat exchanger of the present embodiment does not need to be used as a heat source, for example, only as a cooling tower, a smaller fin pitch, for example, 2.2mm, may be selected.

The spraying system 5 is used for spraying the wet curtain heat exchange medium on the wet curtain so as to form a liquid film of the wet curtain heat exchange medium on the surface of the wet curtain. The wet curtain heat exchange medium is water, for example.

The liquid collecting tank is arranged at the inner lower part of the tower body and is used for collecting wet curtain heat exchange media flowing down from the surface of the wet curtain.

Central air conditioner

According to a second aspect of the present invention, an embodiment of the present invention further provides a central air conditioner, which can cool or both cool and heat, the central air conditioner includes any one of the heat exchange devices 100 described above and a central air conditioner heat exchange medium circulation system, and the heat exchanger 4 of the heat exchange device 100 is communicated with the central air conditioner heat exchange medium circulation system. The central air-conditioning heat exchange medium circulating system is a central air-conditioning refrigerating fluid circulating system or a central air-conditioning cooling fluid circulating system or a central air-conditioning heat preservation fluid circulating system.

The operation of the heat exchange device according to the embodiment of the present invention will be further described below.

1. As cooling towers

Referring to fig. 3 (the wet curtain is arranged side by side with the heat exchanger 4, not shown in the figure), the valve T2 is closed, the valve T1 is opened, the central air-conditioning heat exchange medium on the evaporator Z side is chilled water, the central air-conditioning heat exchange medium on the condenser L side is cooling liquid, such as cooling water, the heat exchange device 100 is communicated with a central air-conditioning cooling liquid circulation system, the cooling liquid is driven by a cooling liquid circulation pump P1 to circulate between the surface air cooler 4 and the condenser L of the central air-conditioning unit M (shown in a dashed line), and the temperature of the cooling liquid rises after the cooling liquid absorbs heat released by the condenser L. Water is used as a wet curtain heat exchange medium and is uniformly sprayed on the wet curtain 2 through the spraying system 5, uniform water films are formed on the surface of the wet curtain, air enters the tower body through the wet curtain, the water films on the wet curtain exchange heat with the air, the air flows through the surface air cooler 4 after being cooled, the heat of the central air conditioner cooling liquid circulating in the surface air cooler 4 is absorbed, and the cooled central air conditioner cooling liquid flows into the central air conditioner unit M again to absorb the heat released by the central air conditioner refrigerant when the condenser L condenses. The hot and humid air in the tower body after absorbing the heat released by the cooling liquid of the central air conditioner is discharged to the atmosphere by the fan 3, and the spray water flows into the liquid collecting tank and is sprayed on the wet curtain again by the spraying system 5. The heat exchange device provided by the embodiment of the invention can reduce the temperature of the cooling liquid of the central air conditioner by more than 8 ℃, can greatly improve the refrigeration efficiency of the central air conditioner, and greatly improve the energy efficiency ratio. In addition, the cooling water of the central air conditioner is in closed circulation, and cannot be exposed to the environment and polluted.

2. As a cold source

Referring to fig. 3, the valve T1 is closed, the valve T2 is opened, the main central air conditioner is closed, and the heat exchange device 100 is communicated with a central air conditioner refrigerant circulation system, for example, chilled water. The central air-conditioning refrigerating fluid is driven by a refrigerating fluid circulating pump P2 to circularly flow between the surface air cooler 4 and a fan coil at a user end of the central air-conditioning, and absorbs the environmental heat at the user end of the central air-conditioning, so that the temperature is increased. Water is used as a wet curtain heat exchange medium and is uniformly sprayed on a wet curtain through the spraying system 5, an even water film is formed on the surface of the wet curtain, air enters the tower body through the wet curtain, the water film on the wet curtain exchanges heat with the air, the air flows through the surface air cooler 4 after being cooled, the heat of the central air-conditioning refrigerating fluid circulating in the surface air cooler 4 is absorbed, and the cooled central air-conditioning refrigerating fluid flows into the central air conditioner again to absorb the environmental heat at the user end of the central air conditioner. In spring, autumn and other suitable seasons, because the environment temperature is lower, the indoor temperature is limited by the air circulation efficiency, and the temperature is higher, at the moment, the indoor refrigeration can be realized only by using the heat exchange device of the embodiment of the invention as a cold source, and the energy can be greatly saved.

3. As a heat source

Referring to fig. 4 (the same system as that of fig. 3, but the operation mode is changed, and for convenience of understanding, fig. 4 is added for description), when heating is required in cold seasons, the evaporator and the condenser are switched by the switching valve, the condenser L of the central air conditioner is used as the evaporator Z, the evaporator Z is used as the condenser L, and the flow direction of the central air conditioning refrigerant is opposite to that of the central air conditioning refrigerant in cooling in summer, that is, the central air conditioning unit is used as a heat pump unit. By closing the valve T2 and opening the valve T1, the heat exchange unit 100 is in communication with a central air conditioning heat retention fluid circulation system, such as antifreeze or low enthalpy salt solution, which does not freeze when circulated to the outdoor surface air cooler 4 during cold seasons. The heat-insulating liquid of the central air conditioner is driven by a heat-insulating liquid circulating pump (namely a cooling liquid circulating pump P1 when the heat-insulating liquid is used as a cooling tower) to circularly flow between the surface air cooler 4 and the evaporator Z of the central air conditioner, and the temperature of the heat-insulating liquid is reduced after the evaporator Z releases heat. The spray system 5 is closed and the wet curtain is not in operation. Air enters the tower body under the action of the fan, heat of the air is absorbed by heat preservation liquid circularly flowing in the surface air cooler 4, cold energy is transferred to the air, the temperature of the heat preservation liquid can approach to the wet bulb temperature of outdoor air, the air in the environment provides stable low-grade heat energy for a central air conditioning system, the heat preservation liquid enters the central air conditioning evaporator Z after being heated, heat required by the evaporator Z in evaporation is provided for a central air conditioning refrigerant, and the central air conditioning refrigerant is condensed and released when circulating to the condenser L. Thus, the heat exchange device according to the embodiment of the present invention can be used as a heat source.

The heat exchange device of the embodiment of the invention firstly uses the wet curtain and the surface air cooler as the outdoor heat exchange device of the central air conditioner, and improves the open system of the central air conditioner in the prior art into the closed system, thereby at least obtaining the following technical effects:

1. the multifunctional central air conditioner can be used as a cooling tower, a cold source and a heat source, and can be randomly selected by a user to be used as one or more of the cooling tower, the cold source and the heat source according to actual conditions.

2. When the cooling tower is used as a cooling tower of a central air conditioner, the heat exchange efficiency is high, the temperature of cooling liquid of the central air conditioner is lower, the refrigeration effect is good, the energy efficiency ratio is high, and the power consumption of a system is reduced.

3. In seasons with proper indoor and outdoor temperature difference, such as spring festival and autumn, the central air conditioning unit can be turned off and directly used as a cold source, so that the power consumption is greatly reduced, the energy is saved, the emission is reduced, the abrasion of the central air conditioning unit is reduced, and the service life of the central air conditioner is prolonged.

4. When heating in cold seasons, the heat pump unit can be used as a heat source, a small amount of high-grade energy is input into the central air conditioning unit used as the heat pump unit, low-grade heat energy can be transferred to high grade in low-temperature environment, energy is saved, heating of a traditional boiler is not needed, and the heating mode is more environment-friendly.

5. In a preferred embodiment, when the heat source is used, the surface cooler does not frost, defrosting is not needed, energy is saved, and a user is ensured to have a continuous and stable heat source.

6. Can be used all year round, and improves the utilization rate of the equipment.

7. The equipment is simple in structure and convenient to maintain.

8. The heat exchange medium of the central air conditioner circulates in the closed heat exchanger, so that the technical problems that the central air conditioner is failed and inconvenient to maintain due to the fact that the central air conditioner cooling liquid of an open system in the prior art is polluted when exposed to the environment are solved.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. 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.