CN218820772U

CN218820772U - Circulating air conditioning system and spraying system

Info

Publication number: CN218820772U
Application number: CN202320066172.3U
Authority: CN
Inventors: 李罡
Original assignee: GAC Aion New Energy Automobile Co Ltd
Current assignee: GAC Aion New Energy Automobile Co Ltd
Priority date: 2023-01-06
Filing date: 2023-01-06
Publication date: 2023-04-07
Anticipated expiration: 2033-01-06

Abstract

The utility model relates to a circulated air conditioning system, including circulated air conditioner and heat pump system, the circulated air conditioner includes cold section of table and heating section, and the circulated air flows through cold section of table and heating section in proper order. The surface cooling section is used for cooling and dehumidifying the circulating air, and the heating section is used for heating the circulating air. The heat pump system comprises an evaporator and a condenser, wherein the evaporator is connected with the condenser. The evaporator absorbs heat and releases cold for cooling the surface cooling section, and the condenser releases heat for heating the heating section. The scheme realizes the cooling of the surface cooling section and the heating of the heating section through one set of heat pump system, thereby effectively reducing the energy consumption and saving the cost.

Description

Circulating air conditioning system and spraying system

Technical Field

The application relates to the field of air conditioning systems, in particular to a circulating air conditioning system and a spraying system.

Background

The circulating air conditioning system is an air conditioning system capable of realizing temperature control and dehumidification. The circulating air conditioning system generally comprises a circulating air pipeline, an air supply device and a circulating air conditioner. The circulating air pipeline is connected between the circulating air conditioner and the target device, the air supply device is installed in the circulating air pipeline and used for enabling air to circulate between the circulating air conditioner and the target device, and the circulating air conditioner is used for controlling temperature and dehumidifying the air so that the air can meet the requirement of the target device.

The circulating air conditioner is provided with a surface cooling section and a heating section, and air flows into the circulating air conditioner and sequentially passes through the surface cooling section and the heating section. When the air current was through the cold section of table, the cold section of table cooled off the air, and relative humidity risees behind the air cooling, reaches 100% back at relative humidity, and the water condensation in the air is separated out to make the absolute humidity of air reduce, thereby the cold dehumidification's of table cold section can be realized effect. The air passes through the heating section again after cold dehumidification, and the heating section heats the air, and relative humidity reduces after the air intensifies, and absolute humidity is unchangeable to the air is heated up to suitable temperature, thereby the heating section can realize the effect of hot intensification. The air then flows through the circulating air pipeline to the target device.

In the prior art, a cooling station is externally connected with a surface cooling section, and the temperature of the surface cooling section is controlled by the cooling station; the heating section is externally connected with a hot water boiler, and the temperature of the heating section is controlled by the hot water boiler. However, the disadvantage of this existing solution is that the cold and heat generated by the cooling station and the hot water boiler cannot directly act on the surface cooling section and the heating section, and need to be converted by the heat exchanger and then transmitted to the surface cooling section and the heating section, so the energy provided by the cooling station and the hot water boiler to the circulating air conditioning system is secondary energy, and the energy loss of the cooling station and the hot water boiler is also large, and the combination of the two problems results in large energy consumption of the circulating air system, which is not only harmful to environmental protection, but also increases the use cost of the circulating air system.

SUMMERY OF THE UTILITY MODEL

An object of the embodiment of the present application is to provide a circulating air conditioning system, which is used for solving the problem of large energy consumption of a circulating air system in the prior art.

The utility model provides a technical scheme as follows:

the application provides a circulated air conditioning system, includes:

the circulating air conditioner comprises a surface cooling section and a heating section, and circulating air sequentially flows through the surface cooling section and the heating section; the surface cooling section is used for cooling and dehumidifying circulating air, and the heating section is used for heating the circulating air;

the heat pump system comprises an evaporator and a condenser, wherein the evaporator is connected with the condenser;

the evaporator absorbs heat and releases cold for cooling the surface cooling section, and the condenser releases heat for heating the heating section.

Preferably, a first pipe and a second pipe are communicated between the evaporator and the surface cooling stage, wherein the refrigerant in the first pipe flows from the evaporator to the surface cooling stage, and the refrigerant in the second pipe flows from the surface cooling stage to the evaporator to form a cooling circuit; the condenser with it has third pipe and fourth pipe to communicate between the heating section, wherein the flow direction of the intraductal fluid of third is for following the condenser flows to the heating section, the flow direction of the intraductal fluid of fourth is for following the heating section flows to the condenser to constitute heating circuit.

This preferred scheme adopts the refrigerant to realize the heat transfer, helps promoting energy utilization efficiency.

As a further preferable mode, the refrigerant flowing through the cooling circuit and the heating circuit is water.

This solution has the advantage of facilitating cost control.

As a further preferred aspect, the cooling circuit is in communication with a makeup system, the makeup system comprising: an input tube in communication with the first tube; an output pipe in communication with the second pipe; the first valve is arranged on the input pipe; and the second valve is arranged on the output pipe.

The advantage of this solution is that the temperature of the refrigerant in the cooling circuit can be adjusted for normal heat exchange.

As a further preferable scheme, the first pipe is communicated with a temperature monitoring device, the temperature monitoring device is used for measuring the temperature of the fluid in the first pipe, and the temperature monitoring device is respectively in electrical communication connection with the first valve and the second valve; wherein the temperature monitoring device is configured to feed back a signal to open the first valve and the second valve when the temperature of the fluid measured by the temperature monitoring device is higher than a predetermined value.

The scheme can automatically realize the effect of supplementing the refrigerant, so that the control method of the circulating air conditioning system is simpler and more convenient.

As a further preferable mode, the cooling circuit is connected to a first pressure stabilizing system, and the first pressure stabilizing system includes: the first pressure stabilizing tube is communicated between the first tube and the second tube; the third valve is arranged on the first pressure stabilizing tube; a first pressure monitoring device in electrical communication with the third valve, the first pressure monitoring device for monitoring the pressure of the fluid within the cooling circuit; wherein the first pressure monitoring device is configured to feed back a signal to actuate the third valve to open when the pressure of the fluid in the cooling circuit is above a predetermined value.

The scheme can realize the adjustment of the pressure of the refrigerant in the cooling circuit, so that the refrigerant can exchange heat fully.

As a further preferable scheme, the heating circuit is communicated with a second pressure stabilizing system, and the second pressure stabilizing system comprises: the second voltage-stabilizing tube is communicated between the third tube and the fourth tube; the fourth valve is arranged on the second pressure stabilizing tube; a second pressure monitoring device in electrical communication with the fourth valve, the second pressure monitoring device for monitoring the pressure of the fluid within the heating circuit; wherein the second pressure monitoring device is configured to feed back a signal to actuate the fourth valve to open when the pressure of the fluid in the heating circuit is higher than a predetermined value.

As a further preferable aspect, the second voltage stabilization system further includes: the return pipe is communicated with the fourth pipe; the fifth valve is arranged on the return pipe; and the pressure regulating device is connected with the return pipe and is used for regulating the fluid pressure in the return pipe.

As a further preferable scheme, the pressure stabilizer is an expansion water tank, and the expansion water tank is communicated with the return pipe and forms a pressure stabilizing loop.

The scheme realizes the control of the pressure of the refrigerant in the heating loop, and aiming at the characteristic that the high-temperature refrigerant is difficult to directly regulate the pressure, the pressure regulating device is additionally arranged to regulate the pressure, so that the refrigerant in the heating loop can also keep normal pressure, and the heat exchange is convenient.

The present application further provides a spray coating system, including:

a spraying room;

the circulating air conditioning system in any preferable scheme is used for providing circulating air for the spraying room.

The scheme has the advantages that the circulating air conditioner realizes the function of controlling the temperatures of the cooling section and the heating section by one set of heat pump system, effectively reduces the energy consumption of the circulating air conditioner system and achieves the effect of saving the cost. Moreover, the heat pump system is a common energy supply system, has the advantages of easy debugging and use, and can not cause the circulating air conditioning system improved by the scheme to become too complex.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic diagram of a preferred embodiment of a circulating air conditioning system according to an embodiment of the present application;

description of reference numerals: 1. circulating air conditioning; 10. a filter screen; 11. a surface cooling section; 12. a heating section; 2. a heat pump system; 21. an evaporator; 22. a condenser; 23. a throttle valve; 24. a compressor; 31. a first tube; 32. a second tube; 33. a third tube; 34. a fourth tube; 41. an input tube; 42. an output pipe; 43. a first valve; 44. a second valve; 45. a temperature monitoring device; 46. a first voltage stabilization system; 461. a first voltage regulator tube; 462. a third valve; 47. a second voltage stabilization system; 471. a second voltage regulator tube; 472. a fourth valve; 473. a return pipe; 474. a fifth valve; 475. a pressure regulating device; 5. a spraying room; 51. a circulating air pipeline; 52. an air supply device.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings or orientations or positional relationships that the product of the application is usually placed in when used, and are used only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present application, it should also be noted that, unless expressly stated or limited otherwise, the terms "disposed" and "connected" are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Fig. 1 is a schematic diagram of a preferred embodiment of a painting system provided by the present application, which includes a circulating air conditioning system and a painting room 5, where the circulating air conditioning system includes a circulating air conditioner 1 and a heat pump system 2, the circulating air conditioner 1 is connected to the painting room 5 through a circulating air pipeline 51, and an air supply device 52 is disposed in the circulating air pipeline 51, and the air supply device 52 can circulate air between the painting room 5 and the circulating air conditioner 1, so that the air forms circulating air, and the temperature and humidity of the air in the painting room 5 meet the requirements of working conditions.

The preferred embodiment of the circulating air conditioner 1 provided in this embodiment includes a filter screen 10, a surface cooling section 11, and a heating section 12, and in the circulating air conditioner 1, circulating air flows through the filter screen 10, the surface cooling section 11, and the heating section 12 in sequence. The filter screen 10 can filter out impurities in the circulating air, and the impurities are prevented from being attached to the surface cooling section 11 and the heating section 12 to influence the heat exchange effect of the surface cooling section and the heating section; the surface cooling section 11 is used for cooling and dehumidifying the circulating air so as to reduce the absolute humidity of the circulating air; the heating section 12 is used for heating the circulating air to enable the temperature of the circulating air to meet requirements. The specific structures of the surface cooling section 11 and the heating section 12 can be designed by directly referring to the prior art, and the specific structures are not specifically described herein.

The heat pump system provided in this embodiment is used to provide both cooling energy to the cold surface section 11 and heat energy to the hot surface section 12. The heat pump system is generally used in the air conditioning field and widely used for heating or cooling, in this embodiment, the heat pump system 2 is the most basic heat pump, and the heat pump system 2 includes an evaporator 21, a condenser 22, a throttle 23 and a compressor 24, but it should be noted that other heat pump systems with existing structures can also be used. Specifically, the evaporator 21, the condenser 22, the throttle 23, and the compressor 24 are connected in series to form a circuit, and a fluid can flow between the evaporator 21, the condenser 22, the throttle 23, and the compressor 24. In the operation process of the heat pump system 2, when fluid flows through the evaporator 21, heat absorption can be carried out and cold energy can be released, so that the released cold energy can be used for continuously cooling the surface cooling section 11; the fluid may release heat and release heat as it passes through the condenser 22, and the released heat may be used to warm the heating section 12. The basic operation principle of the heat pump system 2 belongs to the prior art, and is not described herein. The cold released by the evaporator 21 is applied to maintain the temperature of the surface cooling section 11, so that the surface cooling section 11 can cool and dehumidify the circulating air; similarly, the heat released by condenser 22 is applied to hold heating section 12 to enable heating section 12 to thermally warm the circulating air. In this embodiment, the temperature control of the surface cooling section 11 and the heating section 12 can be simultaneously realized by using one set of heat pump system 2, and the heat pump system 2 has a good energy conversion rate, and the energy lost in the working process is less than that in the prior art, thereby effectively reducing the production cost.

Preferably, a pipeline is provided between the evaporator 21 and the surface cooling section 11, a pipeline is also provided between the condenser 22 and the heating section 12, and a refrigerant flows through the pipeline to exchange heat between the evaporator 21 and the surface cooling section 11 and between the condenser 22 and the heating section 12. Specifically, a first pipe 31 and a second pipe 32 are connected between the evaporator 21 and the surface cooling stage 11, refrigerant flows from the evaporator 21 to the surface cooling stage 11 in the first pipe 31, and refrigerant flows from the surface cooling stage 11 to the evaporator 21 in the second pipe 32, thereby forming a cooling circuit in which refrigerant can circulate between the evaporator 21 and the surface cooling stage 11. The refrigerant is preferably water in order to control costs. Similarly, a third tube 33 and a fourth tube 34 are connected between the condenser 22 and the heating section 12, refrigerant flows from the condenser 22 to the heating section 12 in the third tube 33, and refrigerant flows from the heating section 12 to the condenser 22 in the fourth tube 34, thereby forming a heating circuit for circulating refrigerant between the condenser 22 and the heating section 12. Similarly, the refrigerant circulating between the condenser 22 and the heating section 12 is also preferably water.

The cooling circuit is also connected with a replenishment system, and the replenishment system has the function that when the temperature of the refrigerant in the cooling circuit is too high, the temperature of the refrigerant in the cooling circuit is reduced by introducing low-temperature refrigerant into the cooling circuit, so that the cooling circuit can normally exchange heat with the surface cooling section 11, and the temperature of the surface cooling section 11 can be maintained at a preset value. Specifically, the replenishing system in this embodiment includes an input pipe 41, an output pipe 42, a first valve 43 and a second valve 44, wherein the input pipe 41 is connected to the first pipe 31, the output pipe 42 is connected to the second pipe 32, the first valve 43 is disposed on the input pipe 41, and the second valve 44 is disposed on the output pipe 42. The operation principle of the replenishment system is that when the refrigeration effect of the surface cooling section 11 is found to be unexpected, the first pipe 31 can be filled with low-temperature refrigerant from the outside by opening the first valve 43 and the second valve 44, and the refrigerant originally in the cooling circuit can flow out from the output pipe 42, so as to achieve the functions of replenishment and replacement of the refrigerant. The input pipe 41 is connected to the first pipe 31 for the purpose of directly participating in the heat exchange of the surface cooling section 11, and the output pipe 42 is connected to the second pipe 32 for the purpose of directly flowing out the refrigerant after heat exchange with the surface cooling section 11 without participating in the heat exchange of the condenser 22, which helps to replace the refrigerant without losing the energy of the low-temperature refrigerant charged in the cooling circuit. The specific temperature value of the refrigerant can be set according to the actual situation, and will not be described herein.

In the above solution, the make-up system may be manually operated by an operator, for example, when the humidity of the circulating air flowing out of the circulating air conditioner exceeds a predetermined value, it is proved that the heat exchange effect of the surface cooling section 11 is deteriorated, and at this time, the make-up system may be started to make up the refrigerant. The supply system can also be automatically opened or closed, in a preferred scheme of automatic opening or closing, the input pipe 41 and the output pipe 42 are externally connected with a device capable of automatically supplying the refrigerant, the first pipe 31 is connected with a temperature monitoring device 45, the temperature monitoring device 45 is in telecommunication connection with the first valve 43 and the second valve 44, and the temperature monitoring device 45 can send out an electric signal which can finally realize the control of the first valve 43 and the second valve 44. The device for automatically supplying the refrigerant can be designed by selecting any device capable of supplying fluid according to the prior art, and details are not repeated herein. The temperature monitoring device 45 can directly monitor and measure the temperature of the refrigerant in the first pipe 31, when the temperature of the refrigerant is higher than a certain preset value, the refrigerant cannot maintain the surface cooling section 11 at the preset temperature, the temperature monitoring device 45 sends an electric signal, the electric signal is converted by the main control system, and after the first valve 43 and the second valve 44 finally receive an electric signal, the first valve 43 and the second valve 44 are opened, so that an external device can charge the low-temperature refrigerant into the cooling loop through the replenishment system. When the temperature of the refrigerant in the first pipe 31 is reduced to the preset temperature, the temperature monitoring device 45 sends an electric signal again, and finally drives the first valve 43 and the second valve 44 to close, so that the primary refrigerant replenishing work is realized. The advantage of this solution is that the make-up system can be switched on and off automatically, thus making the control of the circulating air conditioning system simpler.

In addition to the problem of over-high temperature, the refrigerant in the cooling circuit has unstable pressure after long-term use, and therefore the cooling circuit is also connected with a first pressure stabilizing system 46, and the first pressure stabilizing system 46 is used for adjusting the pressure of the refrigerant in the cooling circuit and preventing the refrigerant pressure from influencing heat exchange. Specifically, the first voltage stabilizing system 46 includes a first voltage stabilizing tube 461, a third valve 462 and a first pressure monitoring device, wherein the first voltage stabilizing tube 461 is communicated between the first tube 31 and the second tube 32, the third valve 462 is arranged on the first voltage stabilizing tube 461, the first pressure monitoring device is in telecommunication connection with the third valve 462, and the first pressure monitoring device is used for monitoring the pressure of the refrigerant in the cooling circuit. The first pressure monitoring device may be a pressure gauge, and the specific installation location of the first pressure monitoring device is not shown in the drawings, but it will be understood that the first pressure monitoring device may be installed at any location where the pressure of the refrigerant in the cooling circuit can be monitored, such as the first pipe 31. When the first pressure monitoring device detects that the pressure of the refrigerant in the first pipe 31 is greater than the preset value, the first pressure monitoring device sends an electric signal, the electric signal is converted by the main control system, and finally the third valve 462 is driven to be opened, so that the first pipe 31 is directly communicated with the second pipe 32 and the refrigerant exchange is carried out, and the function of balancing the pressure of the refrigerant in the cooling circuit is achieved. The specific value of the pressure may be set according to actual conditions, and is not limited specifically herein.

Similarly, a second pressure stabilizing system 47 is connected to the heating circuit, and the second pressure stabilizing system 47 is used for balancing the pressure of the refrigerant in the heating circuit. Specifically, the second pressure stabilizing system 47 includes a second pressure stabilizing tube 471, a fourth valve 472 and a second pressure monitoring device, wherein the second pressure stabilizing tube 471 is connected between the third tube 33 and the fourth tube 34, the fourth valve 472 is connected to the second pressure stabilizing tube 471, the second pressure monitoring device is not shown in the figure, but similar to the first pressure monitoring device, the second pressure monitoring device can be installed at any position where the pressure of the refrigerant in the heating circuit can be monitored, for example, the fourth tube 34. The second pressure stabilizing system 47 is in accordance with the first pressure stabilizing system 46, the second pressure stabilizing system 47 monitors the refrigerant pressure in the third pipe 33, and when the pressure is higher than a predetermined value, the fourth valve 472 is opened, so that the third pipe 33 and the fourth pipe 34 are directly communicated, thereby achieving the function of adjusting the pressure of the heating circuit.

However, in view of the high temperature of the refrigerant in the heating circuit, there is a problem that it is still difficult to adjust the pressure of the refrigerant in the heating circuit by the above method, therefore, the second pressure stabilizing system 47 further includes a return pipe 473, a fifth valve 474 and a pressure adjusting device 475, wherein the return pipe 473 is connected to the fourth pipe 34, the fifth valve 474 is arranged on the fourth pipe 34, and the pressure adjusting device 475 can be any existing device capable of adjusting the pressure of the fluid, such as an expansion tank, or can be externally connected to a device capable of providing the refrigerant by referring to a make-up system, and the adjustment of the pressure of the refrigerant in the heating circuit is realized by adjusting the temperature of the refrigerant in the heating circuit. It should be noted that, in the embodiment of connecting the expansion tank, the expansion tank is a conventional device for adjusting the pressure of water, and the specific structure thereof can be adaptively modified and designed with reference to the prior art. The expansion water tank is connected with the return pipe 473, and the expansion water tank and the return pipe 473 form a pressure stabilizing loop to realize the function of adjusting the pressure of the refrigerant in the heating loop.

The air conditioning system with circulating air provided by the embodiment has the advantages that:

1. the energy-saving effect is obvious. In the embodiment, a set of heat pump system 2 is used for realizing two functions of refrigeration and heating, so that the problem of large energy waste caused by using a plurality of sets of equipment is effectively solved.

2. Is convenient to control. The embodiment can realize the function of automatically adjusting the temperature and the pressure of the refrigerant, and ensure that the circulating air conditioning system always works normally, so that the design of the master control system can be very simple. The specific scheme of the master control system can be designed by referring to the prior art for adaptive improvement, and is not described herein in detail.

3. The application scene is wide. Besides being applied to a spraying system, the circulating air conditioning system can also be applied to other scenes with requirements on the ambient temperature and the ambient humidity.

Therefore, the spraying system provided by the embodiment also has the advantages of convenience in control and low energy consumption.

It should be noted that the features of the embodiments in the present application may be combined with each other without conflict.

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

Claims

1. A circulating air conditioning system, comprising:

2. The circulating air conditioning system according to claim 1, wherein a first pipe and a second pipe are communicated between the evaporator and the surface cooling section, wherein the refrigerant in the first pipe flows from the evaporator to the surface cooling section, and the refrigerant in the second pipe flows from the surface cooling section to the evaporator to form a cooling circuit;

the condenser with it has third pipe and fourth pipe to communicate between the heating section, wherein the flow direction of the intraductal fluid of third is for following the condenser flows to the heating section, the flow direction of the intraductal fluid of fourth is for following the heating section flows to the condenser to constitute heating circuit.

3. The circulating air conditioning system of claim 2 wherein the refrigerant circulating in the cooling circuit and the heating circuit is water.

4. The circulating air conditioning system of claim 2 wherein the cooling circuit is in communication with a make-up system, the make-up system comprising:

an input tube in communication with the first tube;

an output pipe in communication with the second pipe;

the first valve is arranged on the input pipe;

and the second valve is arranged on the output pipe.

5. The circulating air conditioning system of claim 4 wherein said first duct is in communication with a temperature monitoring device for measuring the temperature of the fluid in said first duct, said temperature monitoring device being in electrical communication with said first valve and said second valve, respectively;

wherein the temperature monitoring device is configured to feed back a signal to drive the first valve and the second valve to open when the fluid temperature measured by the temperature monitoring device is higher than a predetermined value.

6. The circulating air conditioning system of claim 2 wherein the cooling circuit is in communication with a first pressure stabilizing system, the first pressure stabilizing system comprising:

the first pressure stabilizing tube is communicated between the first tube and the second tube;

the third valve is arranged on the first pressure stabilizing tube;

a first pressure monitoring device in electrical communication with the third valve, the first pressure monitoring device for monitoring the pressure of the fluid within the cooling circuit;

wherein the first pressure monitoring device is configured to feed back a signal to actuate the third valve to open when the pressure of the fluid in the cooling circuit is above a predetermined value.

7. The circulating air conditioning system of claim 2 wherein the heating circuit is in communication with a second pressure stabilizing system, the second pressure stabilizing system comprising:

the second voltage-stabilizing tube is communicated between the third tube and the fourth tube;

the fourth valve is arranged on the second pressure stabilizing tube;

a second pressure monitoring device in communication with the fourth valve, the second pressure monitoring device for monitoring the pressure of the fluid in the heating circuit;

wherein the second pressure monitoring device is configured to feed back a signal to actuate the fourth valve to open when the pressure of the fluid in the heating circuit is higher than a predetermined value.

8. The circulating air conditioning system of claim 7 wherein the second voltage stabilization system further comprises:

the return pipe is communicated with the fourth pipe;

the fifth valve is arranged on the return pipe;

and the pressure regulating device is connected with the return pipe and is used for regulating the fluid pressure in the return pipe.

9. The circulating air conditioning system of claim 8 wherein the pressure stabilizer is an expansion tank, the expansion tank being in communication with the return conduit and forming a pressure stabilizer circuit.

10. A spray coating system, comprising:

a spraying room;

the circulating air conditioning system of any one of claims 1-9, configured to provide circulating air to the spray booth.