Control method of air conditioning system

Abstract

The present invention provides a control method for an air conditioning system. The air conditioning system includes an outdoor unit, at least one indoor unit, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor and a first temperature sensor. The outdoor unit includes a first heat exchanger, a second heat exchanger and a compressor unit. The indoor unit includes a third heat exchanger and a fourth heat exchanger. The control method of the air conditioning system includes: in response to a startup operation instruction, obtaining a target temperature; based on the fact that the return air temperature of the indoor unit is higher than the outdoor ambient temperature, and the difference between the return air temperature and the outdoor ambient temperature is greater than a first temperature difference threshold, a first heat exchange circuit performs heat exchange; obtaining a first pressure of the first pressure sensor, and controlling the compressor unit to work according to the first pressure and the target temperature. By adopting the control method to control the air conditioning system, the two heat exchange systems can be made to work in a superimposed manner, thereby improving the heat exchange capacity of the air conditioning system, making full use of natural cold sources, and reducing the energy consumption of the air conditioning system.

Description

Technical Field

[0001] The present invention belongs to the technical field of air-conditioning systems, and in particular, relates to a control method for an air-conditioning system. Background Art

[0002] In the air-conditioning heat exchange system of the prior art, when a heat pipe refrigeration system and a compressor refrigeration system are included, a common electric valve is provided between the two to switch between the heat pipe mode and the compression refrigeration mode. When the electric valve fails, the two refrigeration systems cannot operate normally, and the system that relies on active control of the electric valve is difficult to effectively utilize the outdoor natural cold source, and the refrigeration efficiency is low. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] To this end, a first aspect of the present invention provides an air conditioning system.

[0005] A second aspect of the present invention provides a control method for an air conditioning system.

[0006] In view of this, a first aspect of the present invention proposes an air-conditioning system, comprising an outdoor unit, the outdoor unit comprising a first heat exchanger, a second heat exchanger and a compressor unit; at least one indoor unit, the indoor unit comprising: a third heat exchanger, a fourth heat exchanger, a return air port and an air outlet, the third heat exchanger being located between the fourth heat exchanger and the return air port; the first heat exchanger and the third heat exchanger are connected end to end to form a first heat exchange circuit; the second heat exchanger, the fourth heat exchanger and the compressor unit are connected end to end in sequence to form a second heat exchange circuit; wherein the first heat exchange circuit and the second heat exchange circuit operate independently of each other, and the first heat exchanger and the third heat exchanger are both heat pipe heat exchangers.

[0007] The air conditioning system provided by the present invention comprises an outdoor unit and at least one indoor unit, and the outdoor unit and the indoor unit are connected by a pipeline. Specifically, the outdoor unit comprises a first heat exchanger, a second heat exchanger and a compressor unit, and the indoor unit comprises a third heat exchanger and a fourth heat exchanger. The first heat exchanger and the third heat exchanger are connected end to end to form a first heat exchange loop. The second heat exchanger, the fourth heat exchanger and the compressor unit are connected end to end in sequence to form a second heat exchange loop. Compared with the previous air conditioning system with only one heat exchange loop, the air conditioning system provided by the present application is provided with two heat exchange loops, which improves the heat exchange effect and enhances the system reliability.

[0008] Furthermore, the first heat exchange circuit and the second heat exchange circuit operate independently of each other without affecting each other, and either heat exchange circuit can also operate normally when the other heat exchange circuit fails.

[0009] Furthermore, the indoor unit also includes an air outlet and a return air outlet, and the third heat exchanger and the fourth heat exchanger are located between the air outlet and the return air outlet, specifically, the third heat exchanger is located between the fourth heat exchanger and the return air outlet. When the first heat exchange loop starts to exchange heat, the third heat exchanger produces a heat exchange effect, and the return air of the indoor unit enters the indoor unit from the return air outlet, first passes through the third heat exchanger for heat exchange, and the air flow temperature after passing through the third heat exchanger changes, and then passes through the fourth heat exchanger and blows out from the air outlet, so that the temperature of the fourth heat exchanger tends to be the same as the air flow temperature. When the second heat exchange loop is not started and operated, the outlet air temperature tends to be the same as the temperature of the fourth heat exchanger. The current outlet air temperature can be obtained by detecting the fourth heat exchanger. When the outlet air temperature does not reach the preset target temperature, it can be judged that the heat exchange demand cannot be met by only the first heat exchange loop, and the second heat exchange loop needs to be started to improve the heat exchange effect.

[0010] In the present application, the first heat exchanger and the second heat exchanger are both heat pipe heat exchangers, and the first heat exchange circuit is a heat pipe heat exchange circuit. It can be understood that the heat pipe heat exchanger can be automatically started when the outdoor ambient temperature is lower than the indoor return air temperature and there is a certain temperature difference between the two, without the need to control it, and is a passive heat exchange system. And the heat pipe heat exchange system is a heat exchange function achieved by natural temperature difference, without the need for other heat exchange devices. Therefore, by designing the first heat exchanger and the second heat exchanger as heat pipe heat exchangers, on the one hand, it is possible to fully utilize the natural cold source and effectively reduce the energy consumption of the air-conditioning system. On the other hand, the first heat exchange system can be started when the outdoor ambient temperature is lower than the indoor return air temperature and there is a certain temperature difference between the two, without the need to control its start and stop through other control devices, thereby improving the reliability of the first heat exchange system and reducing the failure rate.

[0011] By setting a first heat exchange loop and a second heat exchange loop in the air conditioning system and making the two independent of each other, on the one hand, the heat exchange effect of the air conditioning system is improved. Compared with the air conditioning system with only one heat exchange system in the past, the air conditioning system provided by the present application has two heat exchange systems, and the two heat exchange systems can work at the same time, thereby improving the heat exchange capacity. On the other hand, the first heat exchange system is a passive heat exchange system, which can perform heat exchange when the outdoor temperature is lower than the indoor return air temperature and there is a certain temperature difference between the two. The second heat exchange system starts and performs heat exchange when it detects that the first heat exchange system cannot meet the heat exchange demand. The two operate independently of each other and do not affect each other. There is no need to switch between the first heat exchange system and the second heat exchange system through other devices, which reduces the intermediate heat exchange links, reduces the failure rate, and improves the working efficiency and reliability of the air conditioning system.

[0012] The air conditioning system according to the present invention may also have the following additional technical features:

[0013] In the above technical solution, further, the third heat exchanger and the fourth heat exchanger are arranged in parallel.

[0014] In this technical solution, the third heat exchanger is arranged in parallel with the fourth heat exchanger so that the projection areas of the third heat exchanger and the fourth heat exchanger in the same direction are the same. After the return air passes through the third heat exchanger, it can all flow through the fourth heat exchanger without changing the blowing direction, thereby avoiding the situation where part of the return air cannot flow through the location of the fourth heat exchanger, so that the return air can fully exchange heat.

[0015] In any of the above technical solutions, further, the air conditioning system also includes: a first pressure sensor, which is arranged in the second heat exchange circuit, and the first pressure sensor is located at the return air port of the compressor unit.

[0016] In this technical solution, the refrigerant uses a liquid with a low boiling point. When the temperature of the refrigerant itself changes, the pressure in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit also changes. The pressure change in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit can reflect the temperature of the refrigerant, and then reflect the current outlet air temperature.

[0017] In order to obtain the current outlet air temperature, a first pressure sensor is provided in the second heat exchange circuit of the air conditioning system. Specifically, the first pressure sensor is provided at the return air port of the compressor unit. By detecting the pressure at the return air port of the compressor unit through the pressure sensor, the pressure value in the current state can be obtained, and then the outlet air temperature in the current state can be obtained accordingly.

[0018] By setting a first pressure sensor at the return air port of the compressor unit, the outlet air temperature of the indoor unit can be obtained by detecting the pressure value. Compared with the traditional method of directly detecting the outlet air temperature through a temperature measuring device, the present application detects the pressure value of the return air port of the compressor unit and then determines the current outlet air temperature based on the pressure value. It has higher sensitivity and smaller detection error, thereby improving the detection accuracy of the outlet air temperature.

[0019] In any of the above technical solutions, the air-conditioning system further includes: a second pressure sensor, which is arranged in the first heat exchange circuit, and the second pressure sensor is located at the inlet end of the first heat exchanger; a third pressure sensor, which is arranged in the second heat exchange circuit, and the third pressure sensor is located at the inlet end of the second heat exchanger; the outdoor unit also includes at least one fan.

[0020] In this technical solution, the outdoor unit also includes at least one fan, and the fan of the outdoor unit operates according to the pressure at the inlet end of the heat exchanger in the outdoor unit to adjust the pressure of the heat exchanger and improve the heat exchange efficiency.

[0021] In order to detect the pressure at the inlet end of the heat exchanger of the outdoor unit, a second pressure sensor is provided in the first heat exchange circuit, specifically, the second pressure sensor is provided at the inlet end of the first heat exchanger. When the first heat exchange circuit is performing heat exchange and the second heat exchange circuit is not operating, the pressure at the inlet end of the first heat exchanger is detected by the second pressure sensor, and the fan operates according to the detection result.

[0022] Furthermore, the air conditioning system is also provided with a third pressure sensor in the second heat exchange loop, specifically, the third pressure sensor is provided at the inlet end of the second heat exchanger. When the second heat exchange loop is in operation, regardless of whether the first heat exchange loop is in operation, the inlet end pressure of the second heat exchanger is detected by the third pressure sensor, and the fan is operated according to the detection result.

[0023] By setting a second pressure sensor and a third pressure sensor in the air-conditioning system, the inlet pressure of the first heat exchanger and the second heat exchanger can be detected, so that the fan can operate according to the pressure detection result and the pressure of the heat exchanger can be accurately adjusted to improve the heat exchange efficiency.

[0024] In any of the above technical solutions, further, the air-conditioning system also includes: a first temperature sensor, arranged in the second heat exchange circuit, and the first temperature sensor is located at the outlet end of the fourth heat exchanger; a fourth pressure sensor, arranged in the second heat exchange circuit, and the fourth pressure sensor is located between the fourth heat exchanger and the first temperature sensor; a throttle valve, arranged in the second heat exchange circuit, and the throttle valve is located at the inlet end of the fourth heat exchanger.

[0025] In this technical solution, a throttle valve is further provided in the second heat exchange circuit of the air-conditioning system, and specifically, the throttle valve is provided at the inlet end of the fourth heat exchanger. The throttle valve is used to adjust the refrigerant flow at the inlet end of the fourth heat exchanger. In order to obtain the saturation temperature of the refrigerant under the current pressure state, a fourth pressure sensor is provided in the second heat exchange circuit, and specifically, the fourth pressure sensor is provided at the outlet end of the fourth heat exchanger. The current pressure at the outlet end of the fourth heat exchanger is detected by the fourth pressure sensor, and then the saturation temperature of the refrigerant under the current pressure state is obtained according to the pressure detection value.

[0026] Furthermore, a first temperature sensor is provided in the second heat exchange circuit. Specifically, the first temperature sensor is provided at the outlet of the fourth heat exchanger, and is farther away from the outlet of the fourth heat exchanger than the fourth pressure sensor. The refrigerant temperature at the outlet of the fourth heat exchanger is detected by the first temperature sensor, and then the temperature detection result is compared with the refrigerant saturation temperature under the current pressure state, and the opening of the throttle valve is controlled according to the comparison result to adjust the refrigerant flow rate.

[0027] By setting a throttle valve in the air-conditioning system, the refrigerant flow rate of multiple indoor units can be adjusted accordingly at different indoor ambient temperatures to improve the heat exchange capacity of the air-conditioning system and avoid energy waste. By setting a first temperature sensor and a fourth pressure sensor, the actual temperature of the refrigerant can be compared with the saturation temperature of the refrigerant under the current pressure state, and the opening of the throttle valve can be adjusted according to the comparison result to adjust the refrigerant flow rate, so as to improve the heat exchange efficiency of the air-conditioning system and reduce the energy consumption of the air-conditioning system.

[0028] According to the second aspect of the invention, a control method for an air-conditioning system is also proposed, the air-conditioning system comprising an outdoor unit, at least one indoor unit, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor and a first temperature sensor, the outdoor unit comprising a first heat exchanger, a second heat exchanger and a compressor unit, the indoor unit comprising a third heat exchanger and a fourth heat exchanger, the control method for the air-conditioning system comprising: obtaining a target temperature in response to a start-up operation instruction; performing heat exchange in a first heat exchange circuit based on the fact that the return air temperature of the indoor unit is higher than the outdoor ambient temperature, and the difference between the return air temperature and the outdoor ambient temperature is greater than a first temperature difference threshold; obtaining a first pressure of the first pressure sensor, and controlling the operation of the compressor unit according to the first pressure and the target temperature.

[0029] The air-conditioning system to which the control method of the air-conditioning system provided by the present invention is applied includes an outdoor unit and at least one indoor unit, and the outdoor unit and the indoor unit are connected by a pipeline. Specifically, the outdoor unit includes a first heat exchanger, a second heat exchanger and a compressor unit, and the indoor unit includes a third heat exchanger and a fourth heat exchanger. Among them, the first heat exchanger and the third heat exchanger are connected end to end to form a first heat exchange loop. The second heat exchanger, the fourth heat exchanger and the compressor unit are connected end to end in sequence to form a second heat exchange loop. Compared with the air-conditioning system with only one heat exchange loop in the past, the air-conditioning system provided by the present application is provided with two heat exchange loops, which improves the heat exchange effect.

[0030] Among them, the first heat exchanger and the second heat exchanger are both heat pipe heat exchangers, and the first heat exchange loop is a heat pipe heat exchange loop. It can be understood that the heat pipe heat exchanger can be automatically started when there is a certain temperature difference between the indoor return air temperature and the outdoor ambient temperature, without the need to control it, and belongs to a passive heat exchange system. And the heat pipe heat exchange system is a heat exchange function achieved by natural temperature difference, without the need for other heat exchange devices. Therefore, by designing the first heat exchanger and the second heat exchanger as heat pipe heat exchangers, on the one hand, it is possible to fully utilize the natural cold source and effectively reduce the energy consumption of the air-conditioning system. On the other hand, the first heat exchange system can be started when there is a certain temperature difference between the indoor return air temperature and the outdoor ambient temperature, without the need to control its start and stop through other control devices, thereby improving the reliability of the first heat exchange system and reducing the failure rate.

[0031] The control method of the air conditioning system provided by the present invention first responds to the startup operation instruction to obtain the target temperature. Since the first heat exchange circuit is a heat pipe heat exchange circuit, when the return air temperature of the indoor unit is higher than the outdoor ambient temperature and the difference between the return air temperature and the outdoor ambient temperature is greater than the first temperature difference threshold, the first heat exchange circuit automatically performs heat exchange.

[0032] Based on the heat exchange of the first heat exchange loop, the third heat exchanger produces a heat exchange effect. The return air of the indoor unit enters the indoor unit from the return air port, first passes through the third heat exchanger for heat exchange, and the air flow temperature changes after passing through the third heat exchanger. Then, it passes through the fourth heat exchanger and is blown out from the air outlet, so that the temperature of the fourth heat exchanger tends to be the same as the air flow temperature. When the second heat exchange loop is not started, the outlet air temperature tends to be the same as the temperature of the fourth heat exchanger. The current outlet air temperature can be obtained by detecting the fourth heat exchanger. When the outlet air temperature does not reach the preset target temperature, it can be judged that the heat exchange demand cannot be met by only the first heat exchange loop, and the second heat exchange loop needs to be started to improve the heat exchange effect.

[0033] To start the second heat exchange loop, the first pressure of the first pressure sensor is obtained, and the compressor unit is controlled to work according to the first pressure and the target temperature. It can be understood that the fourth heat exchanger is arranged between the third heat exchanger and the air outlet of the indoor unit, and the outlet air after heat exchange by the third heat exchanger blows through the fourth heat exchanger, so that the temperature of the fourth heat exchanger tends to be the same as the outlet air temperature, and the temperature of the refrigerant changes when it flows through the fourth heat exchanger. The refrigerant uses a liquid with a low boiling point. When the temperature of the refrigerant itself changes, the pressure in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit also changes. Specifically, when the temperature of the refrigerant itself increases, the evaporation amount of the refrigerant increases, and the pressure in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit increases. When the temperature of the refrigerant itself decreases, the evaporation amount of the refrigerant decreases, and the pressure in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit decreases. In other words, the pressure change in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit can reflect the temperature of the refrigerant, and then reflect the current outlet air temperature.

[0034] In this technical solution, the first pressure at the return air port of the compressor unit is obtained by the first pressure sensor, and the current outlet air temperature of the indoor unit can be reflected by the first pressure. Whether to start the second heat exchange circuit can be controlled according to the relationship between the outlet air temperature and the target temperature. It can be understood that when the outlet air temperature reaches the target temperature, the second heat exchange circuit is not started, and when the outlet air temperature does not reach the target temperature, the second heat exchange circuit is started.

[0035] By adopting this control method to control the heat exchange circuit of the air conditioning system, the two heat exchange systems can be made to work in a superimposed manner, thereby improving the heat exchange capacity of the air conditioning system, making full use of natural cold sources, and reducing the energy consumption of the air conditioning system. In addition, the first heat exchange circuit and the second heat exchange circuit operate independently of each other without affecting each other, and there is no need to switch between the first heat exchange system and the second heat exchange system through other devices, which reduces the intermediate heat exchange links, reduces the failure rate, and improves the working efficiency and reliability of the air conditioning system.

[0036] In the above technical solution, further, the step of controlling the operation of the compressor group according to the first pressure and the target temperature specifically includes: determining the first pressure threshold according to the target temperature; when the first pressure is greater than or equal to the first pressure threshold, starting a compressor in the compressor group; at an interval of a first preset time, when the first pressure is greater than or equal to the first pressure threshold, increasing the number of compressors started in the compressor group; when the first pressure is less than the second pressure threshold, reducing the number of compressors started in the compressor group; the second pressure threshold is less than the first pressure threshold.

[0037] In this technical solution, the step of controlling the operation of the compressor unit according to the first pressure and the target temperature specifically includes: determining the first pressure threshold according to the target temperature, and starting a compressor in the compressor unit when the first pressure is greater than or equal to the first pressure threshold. The first pressure threshold is obtained according to the target temperature. It can be understood that the pressure value at the return air port of the compressor unit corresponds to the return air temperature, and the first pressure threshold corresponding to it can be obtained accordingly according to the target temperature. When the first pressure is greater than or equal to the first pressure threshold, it means that the current outlet air temperature is higher than the target temperature, that is, the target temperature cannot be reached. At this time, a compressor in the compressor unit should be started, that is, the second heat exchange system should be started to improve the heat exchange effect.

[0038] After starting a compressor in the compressor unit, the second heat exchange system starts to operate, and after a first preset time interval, the compressor is allowed to operate stably for a period of time, and then the first pressure of the return air port of the compressor unit is detected again.

[0039] When the first pressure is still greater than or equal to the first pressure threshold, it indicates that the supply air temperature of the indoor unit still does not reach the target temperature. At this time, the number of compressors started in the compressor unit should be increased to improve the heat exchange effect.

[0040] When the first pressure is less than the second pressure threshold, it indicates that the compressor is over-operating. At this time, the number of compressor starts in the compressor unit should be reduced to avoid energy waste.

[0041] The second pressure threshold is smaller than the first pressure threshold, that is, the first pressure is limited to be within the range defined by the second pressure threshold and the first pressure threshold. If it exceeds the range, it means that the number of compressor starts cannot meet the heat exchange demand.

[0042] By comparing the first pressure with the first pressure threshold and the second pressure threshold, the startup of the compressor group and the startup number of the compressors can be controlled. On the one hand, it can ensure that the number of compressors in operation can meet the current heat exchange demand, which can not only ensure the heat exchange efficiency but also avoid energy waste. On the other hand, the relationship between the supply air temperature and the target temperature is reflected according to the relationship between the first pressure and the first pressure threshold. Compared with directly detecting the supply air temperature, the detection error is reduced and the control accuracy is improved.

[0043] In any of the above technical solutions, further, before controlling the operation of the compressor unit, it also includes: obtaining the second pressure of the second pressure sensor; when the second pressure is greater than or equal to the third pressure threshold, starting a fan; at an interval of a second preset time, when the second pressure is greater than or equal to the third pressure threshold, increasing the number of fan starts; when the second pressure is less than the fourth pressure threshold, reducing the number of fan starts.

[0044] In this technical solution, the outdoor unit of the air-conditioning system is provided with a fan, which adjusts the pressure at the inlet end of the outdoor unit heat exchanger to improve the heat exchange efficiency. Before controlling the compressor unit to work, when only the first heat exchange system is running, the second pressure of the second pressure sensor is obtained. When the second pressure is greater than or equal to the third pressure threshold, it means that the fan needs to be started to reduce the pressure at the inlet end of the second heat exchanger, and a fan is started at this time.

[0045] After starting a fan, a second preset time period is allowed to pass to allow the fan to run stably for a period of time, and then the second pressure is tested again.

[0046] When the second pressure is still greater than or equal to the third pressure threshold, it indicates that the fan cannot meet the use requirements of the system at this time, and the number of fans started should be increased.

[0047] When the second pressure is less than the fourth pressure threshold, it indicates that too many fans are running and the number of fans started should be reduced.

[0048] By comparing the second pressure with the third pressure threshold and the fourth pressure threshold, the start-up and start-up quantity of the fan when only the first heat exchange loop is performing heat exchange can be controlled. This can ensure that the number of running fans can meet the current heat exchange demand, thereby ensuring heat exchange efficiency and avoiding energy waste.

[0049] In any of the above technical solutions, further, after controlling the compressor unit to work, it also includes: obtaining the third pressure of the third pressure sensor; when the third pressure is greater than or equal to the fifth pressure threshold, increasing the number of fan starts; when the third pressure value is less than the sixth pressure threshold, reducing the number of fan starts.

[0050] In this technical solution, after the compressor unit is started, that is, after the second heat exchange circuit begins to exchange heat, the third pressure of the third pressure sensor is obtained. When the third pressure is greater than or equal to the fifth pressure threshold, it means that the fan cannot meet the system's usage requirements at this time, and the number of fan starts is increased.

[0051] When the third pressure is less than the sixth pressure threshold, it indicates that too many fans are running and the number of fans started should be reduced.

[0052] By comparing the third pressure with the fifth pressure threshold and the sixth pressure threshold, the number of fans started when the second heat exchange loop starts to run is controlled. It can ensure that the number of fans in operation can meet the current heat exchange demand, which can not only ensure the heat exchange efficiency but also avoid energy waste. In addition, the first heat exchange loop and the second heat exchange loop share the fan, and the fan is controlled by different control methods when different heat exchange loops are running, so that the first heat exchange loop and the second heat exchange loop do not interfere with each other and are independent of each other.

[0053] In any of the above technical solutions, further, after controlling the compressor unit to work, it also includes: obtaining the fourth pressure of the fourth pressure sensor; determining the first temperature threshold according to the fourth pressure; obtaining the first temperature of the first temperature sensor; when the first temperature is higher than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is greater than or equal to the second temperature difference threshold, increasing the opening of the throttle valve; when the first temperature is lower than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is less than the second temperature difference threshold, reducing the opening of the throttle valve; when the first temperature is higher than or equal to the first temperature threshold, and the difference between the first temperature and the first temperature threshold is less than the second temperature difference threshold, keeping the opening of the throttle valve unchanged. In this technical solution, a throttle valve is provided in the second heat exchange circuit of the air-conditioning system, and the throttle valve is provided at the inlet end of the fourth heat exchanger. The throttle valve is used to adjust the refrigerant flow at the inlet end of the fourth heat exchanger. It can be understood that the number of indoor units can be multiple, and the multiple indoor units can be respectively provided in environments with different temperatures. When the temperatures of the various environments are different, the refrigerant flow required for heat exchange by the fourth heat exchanger in the indoor unit is also different. By providing a throttle valve at the inlet end of the fourth heat exchanger, the flow rate of the refrigerant can be adjusted according to the actual heat exchange demand, thereby improving the heat exchange efficiency.

[0054] In order to obtain the saturation temperature of the refrigerant under the current pressure state, a fourth pressure sensor is provided in the second heat exchange circuit, and specifically, the fourth pressure sensor is provided at the outlet end of the fourth heat exchanger. First, the fourth pressure is obtained by the fourth pressure sensor, and then the first temperature threshold corresponding to the detected fourth pressure is determined, that is, the saturation temperature of the refrigerant under the current pressure.

[0055] Furthermore, a first temperature sensor is provided in the second heat exchange circuit. Specifically, the first temperature sensor is provided at the outlet of the fourth heat exchanger, which is farther away from the outlet of the fourth heat exchanger than the fourth pressure sensor. The first temperature sensor detects the refrigerant temperature at the outlet of the fourth heat exchanger to obtain the first temperature.

[0056] Compare the first temperature with the first temperature threshold. When the first temperature is higher than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is greater than or equal to the second temperature difference threshold, it means that the refrigerant is insufficient at this time and the heat exchange efficiency cannot be guaranteed. The throttle valve opening is controlled to increase and the refrigerant flow rate is increased. When the first temperature is lower than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is less than the second temperature difference threshold, it means that the refrigerant is excessive at this time. The throttle valve opening is controlled to reduce and the refrigerant flow rate is reduced. When the first temperature is higher than or equal to the first temperature threshold, and the difference between the first temperature and the first temperature threshold is less than the second temperature difference threshold, it means that the refrigerant flow rate at this time just meets the use requirements. There is no need to adjust the refrigerant flow rate, and the throttle valve opening can be kept unchanged.

[0057] Specifically, the second temperature difference threshold is 2°C.

[0058] By comparing the first temperature with the first temperature threshold, and accurately controlling the throttle valve opening according to the comparison result, the refrigerant flow rate is adjusted to achieve the best cooling effect. By collecting the fourth pressure and the first temperature, and controlling the throttle valve opening according to the fourth pressure and the first temperature, the actual temperature of the refrigerant can be compared with the saturation temperature of the refrigerant under the current pressure state, and the throttle valve opening can be adjusted according to the comparison result to adjust the refrigerant flow rate, so as to improve the heat exchange efficiency of the air-conditioning system and reduce the energy consumption of the air-conditioning system.

[0059] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0061] Figure 1 A schematic diagram showing an air conditioning system according to an embodiment of the present invention;

[0062] Figure 2 One of the schematic flow charts of the control method of the air conditioning system in the sixth embodiment of the present invention is shown;

[0063] Figure 3 One of the schematic flow charts of the control method of the air conditioning system in the seventh embodiment of the present invention is shown;

[0064] Figure 4 shows one of the schematic flow charts of a method for controlling an air conditioning system in an eighth embodiment of the present invention;

[0065] Figure 5 One of the schematic flow charts of the control method of the air conditioning system in the ninth embodiment of the present invention is shown;

[0066] Figure 6 One of the schematic flow charts of the control method of the air-conditioning system in the tenth embodiment of the present invention is shown.

[0067] in, Figures 1 to 6 The corresponding relationship between the reference numerals and component names in the figure is:

[0068] 100 air conditioning system, 110 outdoor unit, 111 first heat exchanger, 112 second heat exchanger, 113 compressor unit, 120 indoor unit, 121 third heat exchanger, 122 fourth heat exchanger, 123 return air outlet, 124 air outlet, 130 first pressure sensor, 140 second pressure sensor, 150 third pressure sensor, 160 fan, 170 first temperature sensor, 180 fourth pressure sensor, 190 throttle valve. DETAILED DESCRIPTION

[0069] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0070] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0071] Refer to the following Figures 1 to 6 An air conditioning system 100 and a control method of the air conditioning system according to some embodiments of the present invention are described.

[0072] Embodiment 1:

[0073] like Figure 1As shown, an embodiment of the first aspect of the present invention proposes an air-conditioning system 100, including an outdoor unit 110, the outdoor unit 110 includes a first heat exchanger 111, a second heat exchanger 112 and a compressor unit 113; at least one indoor unit 120, the indoor unit 120 includes: a third heat exchanger 121, a fourth heat exchanger 122, a return air port 123 and an air outlet 124, the third heat exchanger 121 is located between the fourth heat exchanger 122 and the return air port 123; the first heat exchanger 111 and the third heat exchanger 121 are connected end to end to form a first heat exchange loop; the second heat exchanger 112, the fourth heat exchanger 122 and the compressor unit 113 are connected end to end in sequence to form a second heat exchange loop; wherein the first heat exchange loop and the second heat exchange loop operate independently of each other, and the first heat exchanger 111 and the third heat exchanger 121 are both heat pipe heat exchangers.

[0074] The air conditioning system 100 provided by the present invention includes an outdoor unit 110 and at least one indoor unit 120, and the outdoor unit 110 and the indoor unit 120 are connected by a pipeline. Specifically, the outdoor unit 110 includes a first heat exchanger 111, a second heat exchanger 112 and a compressor unit 113, and the indoor unit 120 includes a third heat exchanger 121 and a fourth heat exchanger 122. Among them, the first heat exchanger 111 and the third heat exchanger 121 are connected end to end to form a first heat exchange loop. The second heat exchanger 112, the fourth heat exchanger 122 and the compressor unit 113 are connected end to end in sequence to form a second heat exchange loop. Compared with the air conditioning system 100 with only one heat exchange loop in the past, the air conditioning system 100 provided by the present application is provided with two heat exchange loops, which improves the heat exchange effect and enhances the system reliability.

[0075] Furthermore, the first heat exchange circuit and the second heat exchange circuit operate independently of each other without affecting each other, and either heat exchange circuit can also operate normally when the other heat exchange circuit fails.

[0076] Furthermore, the indoor unit 120 further includes an air outlet 124 and a return air outlet 123, and the third heat exchanger 121 and the fourth heat exchanger 122 are located between the air outlet 124 and the return air outlet 123. Specifically, the third heat exchanger 121 is located between the fourth heat exchanger 122 and the return air outlet 123. When the first heat exchange loop starts to exchange heat, the third heat exchanger 121 produces a heat exchange effect, and the return air of the indoor unit 120 enters the indoor unit 120 from the return air outlet 123, first passes through the third heat exchanger 121 for heat exchange, and the temperature of the air flow after passing through the third heat exchanger 121 changes, and then passes through the fourth heat exchanger 122 and is blown out from the air outlet 124, so that the temperature of the fourth heat exchanger 122 tends to be the same as the temperature of the air flow. When the second heat exchange loop is not started, the outlet air temperature is close to the temperature of the fourth heat exchanger 122. The current outlet air temperature can be obtained by detecting the fourth heat exchanger 122. When the outlet air temperature does not reach the preset target temperature, it can be determined that the heat exchange demand cannot be met by the first heat exchange loop alone, and the second heat exchange loop needs to be started to improve the heat exchange effect.

[0077] In the present application, the first heat exchanger 111 and the second heat exchanger 112 are both heat pipe heat exchangers, and the first heat exchange loop is a heat pipe heat exchange loop. It can be understood that the heat pipe heat exchanger can be automatically started when the outdoor ambient temperature is lower than the indoor return air temperature and there is a certain temperature difference between the two, without the need to control it, and belongs to a passive heat exchange system. And the heat pipe heat exchange system is a heat exchange function achieved by natural temperature difference, without the need for other heat exchange devices. Therefore, by designing the first heat exchanger 111 and the second heat exchanger 112 as heat pipe heat exchangers, on the one hand, it is possible to fully utilize the natural cold source and effectively reduce the energy consumption of the air conditioning system 100. On the other hand, the first heat exchange system can be started when the outdoor ambient temperature is lower than the indoor return air temperature and there is a certain temperature difference between the two, without the need to control its start and stop through other control devices, thereby improving the reliability of the first heat exchange system and reducing the failure rate.

[0078] The present application improves the heat exchange effect of the air conditioning system 100 by setting a first heat exchange loop and a second heat exchange loop in the air conditioning system 100 and making the two independent of each other. Compared with the air conditioning system 100 with only one heat exchange system in the past, the air conditioning system 100 provided by the present application has two heat exchange systems, and the two heat exchange systems can work at the same time, thereby improving the heat exchange capacity. On the other hand, the first heat exchange system is a passive heat exchange system, which can perform heat exchange when the outdoor temperature is lower than the indoor return air temperature and there is a certain temperature difference between the two. The second heat exchange system starts and performs heat exchange when it detects that the first heat exchange system cannot meet the heat exchange demand. The two operate independently of each other and do not affect each other. There is no need to switch between the first heat exchange system and the second heat exchange system through other devices, which reduces the intermediate heat exchange links, reduces the failure rate, and improves the working efficiency and reliability of the air conditioning system 100.

[0079] Embodiment 2:

[0080] like Figure 1 As shown, based on Example 1, Example 2 provides an air conditioning system 100, in which the third heat exchanger 121 and the fourth heat exchanger 122 are arranged in parallel.

[0081] In this design, the third heat exchanger 121 and the fourth heat exchanger 122 are arranged in parallel, so that the projection areas of the third heat exchanger 121 and the fourth heat exchanger 122 in the same direction are the same. After the return air passes through the third heat exchanger 121, it can all flow through the fourth heat exchanger 122 without changing the blowing direction, thereby avoiding the situation where part of the return air cannot flow through the location of the fourth heat exchanger 122, so that the return air can fully exchange heat.

[0082] Embodiment 3:

[0083] like Figure 1 As shown, based on Example 1, Example 3 provides an air conditioning system 100 , further comprising: a first pressure sensor 130 , which is arranged in the second heat exchange circuit, and the first pressure sensor 130 is located at the return air port of the compressor unit 113 .

[0084] In this design, the fourth heat exchanger 122 is arranged between the third heat exchanger 121 and the air outlet 124 of the indoor unit 120. The outlet air after heat exchange in the third heat exchanger 121 blows through the fourth heat exchanger 122, so that the temperature of the fourth heat exchanger 122 tends to be the same as the outlet air temperature. When the refrigerant flows through the fourth heat exchanger 122, the temperature changes. The refrigerant uses a liquid with a low boiling point. When the temperature of the refrigerant itself changes, the pressure in the pipeline between the outlet end of the fourth heat exchanger 122 and the return air port of the compressor unit 113 also changes. Specifically, when the temperature of the refrigerant itself increases, the evaporation amount of the refrigerant increases, and the pressure in the pipeline between the outlet end of the fourth heat exchanger 122 and the return air port of the compressor unit 113 increases. When the temperature of the refrigerant itself decreases, the evaporation amount of the refrigerant decreases, and the pressure in the pipeline between the outlet end of the fourth heat exchanger 122 and the return air port of the compressor unit 113 decreases. That is to say, the pressure change in the pipeline between the outlet end of the fourth heat exchanger 122 and the return air port of the compressor unit 113 can reflect the temperature of the refrigerant, and further reflect the current outlet air temperature.

[0085] In order to obtain the current outlet air temperature, a first pressure sensor 130 is provided in the second heat exchange circuit of the air conditioning system 100. Specifically, the first pressure sensor 130 is provided at the return air port of the compressor unit 113. By detecting the pressure at the return air port of the compressor unit 113 through the pressure sensor, the pressure value in the current state can be obtained, and then the outlet air temperature in the current state can be obtained accordingly.

[0086] By setting a first pressure sensor 130 at the return air port of the compressor unit 113, the outlet air temperature of the indoor unit 120 can be obtained by detecting the pressure value. Compared with the traditional method of directly detecting the outlet air temperature through a temperature measuring device, the present application detects the pressure value of the return air port of the compressor unit 113, and then determines the current outlet air temperature based on the pressure value. It has higher sensitivity and smaller detection error, thereby improving the detection accuracy of the outlet air temperature.

[0087] Embodiment 4:

[0088] like Figure 1 As shown, based on Example 1, Example 4 provides an air-conditioning system 100, which also includes: a second pressure sensor 140, which is arranged in the first heat exchange circuit, and the second pressure sensor 140 is located at the inlet end of the first heat exchanger 111; a third pressure sensor 150, which is arranged in the second heat exchange circuit, and the third pressure sensor 150 is located at the inlet end of the second heat exchanger 112; the outdoor unit 110 also includes at least one fan 160.

[0089] In this design, the outdoor unit 110 also includes at least one fan 160. When any heat exchange circuit of the air conditioning system 100 performs heat exchange, the refrigerant in the heat exchange system starts to flow for heat exchange. It can be understood that when the pressure at the inlet end of the heat exchanger is too high, the heat exchange efficiency of the heat exchanger decreases, and the refrigerant cannot have a good heat exchange effect. When the pressure at the inlet end of the heat exchanger is too low, it is no longer necessary to reduce the pressure through the fan 160. The fan 160 of the outdoor unit 110 operates according to the inlet end pressure of the heat exchanger in the outdoor unit 110 to adjust the pressure of the heat exchanger and improve the heat exchange efficiency.

[0090] In order to detect the pressure at the inlet end of the heat exchanger of the outdoor unit 110, a second pressure sensor 140 is provided in the first heat exchange loop, specifically, the second pressure sensor 140 is provided at the inlet end of the first heat exchanger 111. When the first heat exchange loop is performing heat exchange and the second heat exchange loop is not operating, the pressure at the inlet end of the first heat exchanger 111 is detected by the second pressure sensor 140, and the fan 160 operates according to the detection result.

[0091] Furthermore, the air conditioning system 100 is also provided with a third pressure sensor 150 in the second heat exchange loop, and specifically, the third pressure sensor 150 is provided at the inlet end of the second heat exchanger 112. When the second heat exchange loop is in operation, regardless of whether the first heat exchange loop is in operation, the inlet end pressure of the second heat exchanger 112 is detected by the third pressure sensor 150, and the fan 160 operates according to the detection result.

[0092] By setting a second pressure sensor 140 and a third pressure sensor 150 in the air-conditioning system 100, the inlet pressure of the first heat exchanger 111 and the second heat exchanger 112 can be detected, so that the fan 160 operates according to the pressure detection result and the pressure of the heat exchanger is accurately adjusted to improve the heat exchange efficiency.

[0093] Embodiment 5:

[0094] like Figure 1 As shown, based on any of the above embodiments, embodiment 5 provides an air-conditioning system 100, further comprising: a first temperature sensor 170, arranged in the second heat exchange circuit, and the first temperature sensor 170 is located at the outlet end of the fourth heat exchanger 122; a fourth pressure sensor 180, arranged in the second heat exchange circuit, and the fourth pressure sensor 180 is located between the fourth heat exchanger 122 and the first temperature sensor 170; a throttle valve 190, arranged in the second heat exchange circuit, and the throttle valve 190 is located at the inlet end of the fourth heat exchanger 122.

[0095] In this design, a throttle valve 190 is further provided in the second heat exchange circuit of the air conditioning system 100. Specifically, the throttle valve 190 is provided at the inlet end of the fourth heat exchanger 122. The throttle valve 190 is used to adjust the refrigerant flow at the inlet end of the fourth heat exchanger 122. It can be understood that the number of indoor units 120 can be multiple, and the multiple indoor units 120 can be respectively provided in environments with different temperatures. When the temperatures of the various environments are different, the refrigerant flow required for heat exchange by the fourth heat exchanger 122 in the indoor unit 120 is also different. By providing the throttle valve 190 at the inlet end of the fourth heat exchanger 122, the flow of the refrigerant can be adjusted according to the actual heat exchange demand to improve the heat exchange efficiency. Specifically, the throttle valve 190 adjusts the opening of the throttle valve 190 according to the relationship between the temperature of the refrigerant in the current state and the saturation temperature in the current pressure state. It can be understood that under different pressures, the saturation temperature of the refrigerant is different. When the actual temperature of the refrigerant exceeds the saturation temperature, the heat exchange capacity of the refrigerant decreases.

[0096] In order to obtain the saturated temperature of the refrigerant under the current pressure state, a fourth pressure sensor 180 is provided in the second heat exchange circuit, and specifically, the fourth pressure sensor 180 is provided at the outlet end of the fourth heat exchanger 122. The current pressure at the outlet end of the fourth heat exchanger 122 is detected by the fourth pressure sensor 180, and then the saturated temperature of the refrigerant under the current pressure state is obtained according to the pressure detection value.

[0097] Furthermore, a first temperature sensor 170 is further provided in the second heat exchange circuit. Specifically, the first temperature sensor 170 is provided at the outlet end of the fourth heat exchanger 122, which is far away from the outlet end of the fourth heat exchanger 122 relative to the fourth pressure sensor 180. The refrigerant temperature at the outlet end of the fourth heat exchanger 122 is detected by the first temperature sensor 170, and then the temperature detection result is compared with the refrigerant saturation temperature under the current pressure state, and the opening of the throttle valve 190 is controlled according to the comparison result to adjust the refrigerant flow rate.

[0098] The number of the first temperature sensors 170 and the fourth pressure sensors 180 is the same as the number of the throttle valves 190 , and the first temperature sensors 170 , the fourth pressure sensors 180 and the throttle valves 190 are arranged in a one-to-one correspondence.

[0099] By setting the throttle valve 190 in the air conditioning system 100, the refrigerant flow rate of the plurality of indoor units 120 can be adjusted accordingly at different indoor ambient temperatures to improve the heat exchange capacity of the air conditioning system 100 and avoid energy waste. By setting the first temperature sensor 170 and the fourth pressure sensor 180, the actual temperature of the refrigerant can be compared with the saturation temperature of the refrigerant under the current pressure state, and the opening of the throttle valve 190 can be adjusted according to the comparison result to adjust the refrigerant flow rate, so as to improve the heat exchange efficiency of the air conditioning system 100 and reduce the energy consumption of the air conditioning system 100.

[0100] Embodiment 6:

[0101] The embodiment of the second aspect of the present invention provides a control method for an air conditioning system, the air conditioning system includes an outdoor unit 110, at least one indoor unit 120, a first pressure sensor 130, a second pressure sensor 140, a third pressure sensor 150, a fourth pressure sensor 180 and a first temperature sensor 170, the outdoor unit 110 includes a first heat exchanger 111, a second heat exchanger 112 and a compressor unit 113, and the indoor unit 120 includes a third heat exchanger 121 and a fourth heat exchanger 122. Figure 2 As shown, the control method of the air conditioning system specifically includes:

[0102] Step S202: Responding to the startup instruction, obtaining the target temperature;

[0103] Step S204: based on the return air temperature of the indoor unit being higher than the outdoor ambient temperature, and the difference between the return air temperature and the outdoor ambient temperature being greater than a first temperature difference threshold, the first heat exchange circuit performs heat exchange;

[0104] Step S206: Obtain the first pressure of the first pressure sensor, and control the operation of the compressor unit according to the first pressure and the target temperature.

[0105] The air-conditioning system to which the control method of the air-conditioning system provided by the present invention is applied includes an outdoor unit and at least one indoor unit, and the outdoor unit and the indoor unit are connected by a pipeline. Specifically, the outdoor unit includes a first heat exchanger, a second heat exchanger and a compressor unit, and the indoor unit includes a third heat exchanger and a fourth heat exchanger. Among them, the first heat exchanger and the third heat exchanger are connected end to end to form a first heat exchange loop. The second heat exchanger, the fourth heat exchanger and the compressor unit are connected end to end in sequence to form a second heat exchange loop. Compared with the air-conditioning system with only one heat exchange loop in the past, the air-conditioning system provided by the present application is provided with two heat exchange loops, which improves the heat exchange effect.

[0106] Among them, the first heat exchanger and the second heat exchanger are both heat pipe heat exchangers, and the first heat exchange loop is a heat pipe heat exchange loop. It can be understood that the heat pipe heat exchanger can be automatically started when there is a certain temperature difference between the indoor return air temperature and the outdoor ambient temperature, without the need to control it, and belongs to a passive heat exchange system. And the heat pipe heat exchange system is a heat exchange function achieved by natural temperature difference, without the need for other heat exchange devices. Therefore, by designing the first heat exchanger and the second heat exchanger as heat pipe heat exchangers, on the one hand, it is possible to fully utilize the natural cold source and effectively reduce the energy consumption of the air-conditioning system. On the other hand, the first heat exchange system can be started when there is a certain temperature difference between the indoor return air temperature and the outdoor ambient temperature, without the need to control its start and stop through other control devices, thereby improving the reliability of the first heat exchange system and reducing the failure rate.

[0107] The control method of the air conditioning system provided by the present invention first responds to the startup operation instruction to obtain the target temperature. Since the first heat exchange circuit is a heat pipe heat exchange circuit, when the return air temperature of the indoor unit is higher than the outdoor ambient temperature and the difference between the return air temperature and the outdoor ambient temperature is greater than the first temperature difference threshold, the first heat exchange circuit automatically performs heat exchange.

[0108] Based on the heat exchange of the first heat exchange loop, the third heat exchanger produces a heat exchange effect. The return air of the indoor unit enters the indoor unit from the return air port, first passes through the third heat exchanger for heat exchange, and the air flow temperature changes after passing through the third heat exchanger. Then, it passes through the fourth heat exchanger and is blown out from the air outlet, so that the temperature of the fourth heat exchanger tends to be the same as the air flow temperature. When the second heat exchange loop is not started, the outlet air temperature tends to be the same as the temperature of the fourth heat exchanger. The current outlet air temperature can be obtained by detecting the fourth heat exchanger. When the outlet air temperature does not reach the preset target temperature, it can be judged that the heat exchange demand cannot be met by only the first heat exchange loop, and the second heat exchange loop needs to be started to improve the heat exchange effect.

[0109] To start the second heat exchange loop, the first pressure of the first pressure sensor is obtained, and the compressor unit is controlled to work according to the first pressure and the target temperature. It can be understood that the fourth heat exchanger is arranged between the third heat exchanger and the air outlet of the indoor unit, and the outlet air after heat exchange by the third heat exchanger blows through the fourth heat exchanger, so that the temperature of the fourth heat exchanger tends to be the same as the outlet air temperature, and the temperature of the refrigerant changes when it flows through the fourth heat exchanger. The refrigerant uses a liquid with a low boiling point. When the temperature of the refrigerant itself changes, the pressure in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit also changes. Specifically, when the temperature of the refrigerant itself increases, the evaporation amount of the refrigerant increases, and the pressure in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit increases. When the temperature of the refrigerant itself decreases, the evaporation amount of the refrigerant decreases, and the pressure in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit decreases. In other words, the pressure change in the pipeline between the outlet end of the fourth heat exchanger and the return air port of the compressor unit can reflect the temperature of the refrigerant, and then reflect the current outlet air temperature.

[0110] In this design, the first pressure at the return air port of the compressor unit is obtained through the first pressure sensor, and the first pressure can reflect the current outlet air temperature of the indoor unit. According to the relationship between the outlet air temperature and the target temperature, whether to start the second heat exchange loop can be controlled. It can be understood that when the outlet air temperature reaches the target temperature, the second heat exchange loop is not started, and when the outlet air temperature does not reach the target temperature, the second heat exchange loop is started.

[0111] By adopting this control method to control the heat exchange circuit of the air conditioning system, the two heat exchange systems can be made to work in a superimposed manner, thereby improving the heat exchange capacity of the air conditioning system, making full use of natural cold sources, and reducing the energy consumption of the air conditioning system. In addition, the first heat exchange circuit and the second heat exchange circuit operate independently of each other without affecting each other, and there is no need to switch between the first heat exchange system and the second heat exchange system through other devices, which reduces the intermediate heat exchange links, reduces the failure rate, and improves the working efficiency and reliability of the air conditioning system.

[0112] Embodiment 7:

[0113] like Figure 3 As shown, based on Example 6, Example 7 provides a control method for an air-conditioning system, and the steps of controlling the operation of the compressor unit according to the first pressure and the target temperature specifically include:

[0114] Step S302: determining a first pressure threshold according to a target temperature;

[0115] Step S304: when the first pressure is greater than or equal to the first pressure threshold, starting a compressor in the compressor group;

[0116] Step S306: at a first preset time interval, when the first pressure is greater than or equal to the first pressure threshold, increasing the number of compressors started in the compressor group;

[0117] Step S308: When the first pressure is less than the second pressure threshold, reducing the number of compressors to be started in the compressor group.

[0118] The second pressure threshold is less than the first pressure threshold.

[0119] In this design, the step of controlling the operation of the compressor unit according to the first pressure and the target temperature specifically includes: determining the first pressure threshold according to the target temperature, and starting a compressor in the compressor unit when the first pressure is greater than or equal to the first pressure threshold. The first pressure threshold is obtained according to the target temperature. It can be understood that the pressure value at the return air port of the compressor unit corresponds to the return air temperature, and the first pressure threshold corresponding to it can be obtained accordingly according to the target temperature. When the first pressure is greater than or equal to the first pressure threshold, it means that the current outlet air temperature is higher than the target temperature, that is, the target temperature cannot be reached. At this time, a compressor in the compressor unit should be started, that is, the second heat exchange system should be started to improve the heat exchange effect.

[0120] After starting a compressor in the compressor unit, the second heat exchange system starts to operate, and after a first preset time interval, the compressor is allowed to operate stably for a period of time, and then the first pressure of the return air port of the compressor unit is detected again.

[0121] When the first pressure is still greater than or equal to the first pressure threshold, it indicates that the supply air temperature of the indoor unit still does not reach the target temperature. At this time, the number of compressors started in the compressor unit should be increased to improve the heat exchange effect.

[0122] It is understandable that too high pressure or too low pressure will lead to a decrease in heat exchange efficiency. Specifically, the first pressure threshold should be within the first pressure threshold range, so as to ensure that the first pressure is within a reasonable range to ensure the heat exchange efficiency of the air conditioning system. Specifically, the first pressure threshold range is 7 bar to 14 bar, and preferably, the first pressure threshold is 12.5 bar.

[0123] Further, when the first pressure is measured to be greater than or equal to the first pressure threshold, the timing starts, and if the duration of the first pressure being greater than or equal to the first pressure threshold reaches the first pressure detection duration, the number of starts of the compressor is increased, otherwise the number of starts of the compressor remains unchanged. Specifically, the first pressure detection duration can be 1s to 180s, and preferably, the first pressure detection duration is 30s.

[0124] Furthermore, the compressor to be started is selected according to the wear balance principle, that is, the working hours of all the compressors in the compressor group are sorted, and the compressors with shorter working hours are started first.

[0125] Specifically, the number of compressors started may be increased one at a time.

[0126] When the first pressure is less than the second pressure threshold, it indicates that the compressor is over-operating. At this time, the number of compressor starts in the compressor unit should be reduced to avoid energy waste.

[0127] Specifically, the second pressure threshold should also be within the range of the first pressure threshold, so as to ensure that the second pressure is within a reasonable range to ensure the heat exchange efficiency of the air conditioning system. Preferably, the second pressure threshold is 9.9 bar.

[0128] Further, when the first pressure is measured to be less than the second pressure threshold, the timing starts, and if the duration of the first pressure being less than the second pressure threshold reaches the second pressure detection duration, the number of compressor starts is reduced, otherwise the number of compressor starts remains unchanged. Specifically, the second pressure detection duration can be 1s to 180s, and preferably, the second pressure detection duration is 30s.

[0129] Furthermore, the compressor to be stopped is selected according to the wear balance principle, that is, the working hours of all the compressors in the compressor group are sorted, and the compressors with longer working hours are stopped first.

[0130] Specifically, the number of starts of one compressor at a time can be reduced.

[0131] The second pressure threshold is smaller than the first pressure threshold, that is, the first pressure is limited to be within the range defined by the second pressure threshold and the first pressure threshold. If it exceeds the range, it means that the number of compressor starts cannot meet the heat exchange demand.

[0132] By comparing the first pressure with the first pressure threshold and the second pressure threshold, the startup of the compressor group and the startup number of the compressors can be controlled. On the one hand, it can ensure that the number of compressors in operation can meet the current heat exchange demand, which can not only ensure the heat exchange efficiency but also avoid energy waste. On the other hand, the relationship between the supply air temperature and the target temperature is reflected according to the relationship between the first pressure and the first pressure threshold. Compared with directly detecting the supply air temperature, the detection error is reduced and the control accuracy is improved.

[0133] Embodiment 8:

[0134] like Figure 4 As shown, based on Example 6, Example 8 provides a control method for an air conditioning system, which, before controlling the compressor unit to work, further includes:

[0135] Step S402: Acquire a second pressure of a second pressure sensor;

[0136] Step S404: when the second pressure is greater than or equal to the third pressure threshold, start a fan;

[0137] Step S406: at a second preset time interval, when the second pressure is greater than or equal to the third pressure threshold, increasing the number of fans started;

[0138] Step S408: When the second pressure is less than the fourth pressure threshold, the number of fans started is reduced.

[0139] In this design, the outdoor unit of the air conditioning system is provided with a fan, which adjusts the pressure at the inlet end of the outdoor unit heat exchanger to improve the heat exchange efficiency. Before controlling the compressor unit to work, when only the first heat exchange system is running, the second pressure of the second pressure sensor is obtained. When the second pressure is greater than or equal to the third pressure threshold, it means that the fan needs to be started to reduce the pressure at the inlet end of the second heat exchanger, and a fan is started at this time.

[0140] After starting a fan, a second preset time period is allowed to pass to allow the fan to run stably for a period of time, and then the second pressure is tested again.

[0141] When the second pressure is still greater than or equal to the third pressure threshold, it indicates that the fan cannot meet the use requirements of the system at this time, and the number of fans started should be increased.

[0142] It is understandable that too high or too low pressure of the heat exchanger will lead to reduced heat exchange efficiency. Specifically, the third pressure threshold should be within the range of the second pressure threshold, so as to ensure that the second pressure is within a reasonable range to ensure the heat exchange efficiency of the air conditioner. Specifically, the second pressure threshold range is 11.6 bar to 20 bar, and preferably, the third pressure threshold is 15.6 bar.

[0143] Further, when the second pressure is measured to be greater than or equal to the third pressure threshold, the timing starts, and if the duration of the second pressure being greater than or equal to the third pressure threshold reaches the third pressure detection duration, the number of fan starts is increased, otherwise the number of fan starts remains unchanged. Specifically, the third pressure detection duration can be 1s to 180s, and preferably, the third pressure detection duration is 3s.

[0144] Specifically, the number of compressors started may be increased one at a time.

[0145] When the second pressure is less than the fourth pressure threshold, it indicates that too many fans are running and the number of fans started should be reduced.

[0146] It is understandable that too high or too low pressure of the heat exchanger will lead to reduced heat exchange efficiency. Specifically, the fourth pressure threshold should be within the range of the second pressure threshold, so as to ensure that the second pressure is within a reasonable range to ensure the heat exchange efficiency of the air conditioner. Preferably, the fourth pressure threshold is 13.3 bar.

[0147] Further, when the second pressure is measured to be less than the fourth pressure threshold, the timing starts, and if the duration of the second pressure being less than the fourth pressure threshold reaches the fourth pressure detection duration, the number of fan starts is reduced, otherwise the number of fan starts remains unchanged. Specifically, the fourth pressure detection duration can be 1s to 180s, and preferably, the fourth pressure detection duration is 3s.

[0148] Specifically, the number of starts of one compressor at a time can be reduced.

[0149] By comparing the second pressure with the third pressure threshold and the fourth pressure threshold, the start-up and start-up quantity of the fan when only the first heat exchange loop is performing heat exchange can be controlled. This can ensure that the number of running fans can meet the current heat exchange demand, thereby ensuring heat exchange efficiency and avoiding energy waste.

[0150] Embodiment 9:

[0151] like Figure 5 As shown, based on Example 8, Example 9 provides a control method for an air conditioning system, which, after controlling the compressor unit to work, further includes:

[0152] Step S502: obtaining a third pressure from a third pressure sensor;

[0153] Step S504: when the third pressure is greater than or equal to the fifth pressure threshold, increase the number of fans started;

[0154] Step S506: when the third pressure value is less than the sixth pressure threshold, reducing the number of fans started.

[0155] In this design, after the compressor unit is started, that is, after the second heat exchange circuit begins to exchange heat, the third pressure of the third pressure sensor is obtained. When the third pressure is greater than or equal to the fifth pressure threshold, it means that the fan cannot meet the system's usage requirements at this time, and the number of fan starts is increased.

[0156] It can be understood that too high or too low pressure of the heat exchanger will lead to reduced heat exchange efficiency. Specifically, the fifth pressure threshold should be within the range of the third pressure threshold, thereby ensuring that the third pressure is within a reasonable range to ensure the heat exchange efficiency of the air conditioner.

[0157] Further, when the third pressure is measured to be greater than or equal to the fifth pressure threshold, timing starts. If the duration for which the third pressure is greater than or equal to the fifth pressure threshold reaches the fifth pressure detection duration, the number of fan starts is increased; otherwise, the number of fan starts is kept unchanged.

[0158] Specifically, the number of compressors started may be increased one at a time.

[0159] When the third pressure is less than the sixth pressure threshold, it indicates that too many fans are running and the number of fans started should be reduced.

[0160] It can be understood that too high or too low pressure of the heat exchanger will lead to reduced heat exchange efficiency. Specifically, the sixth pressure threshold should be within the range of the third pressure threshold, thereby ensuring that the third pressure is within a reasonable range to ensure the heat exchange efficiency of the air conditioner.

[0161] Further, when the third pressure is measured to be less than the sixth pressure threshold, timing starts. If the time duration during which the third pressure is less than the sixth pressure threshold reaches the sixth pressure detection time duration, the number of fan starts is reduced; otherwise, the number of fan starts is kept unchanged.

[0162] Specifically, the number of starts of one compressor at a time can be reduced.

[0163] By comparing the third pressure with the fifth pressure threshold and the sixth pressure threshold, the number of fans started when the second heat exchange loop starts to run is controlled. It can ensure that the number of fans in operation can meet the current heat exchange demand, which can not only ensure the heat exchange efficiency but also avoid energy waste. In addition, the first heat exchange loop and the second heat exchange loop share the fan, and the fan is controlled by different control methods when different heat exchange loops are running, so that the first heat exchange loop and the second heat exchange loop do not interfere with each other and are independent of each other.

[0164] Embodiment 10:

[0165] like Figure 6 As shown, based on Example 6, Example 10 provides a control method for an air conditioning system, which, after controlling the compressor unit to work, further includes:

[0166] Step S602: obtaining a fourth pressure of a fourth pressure sensor;

[0167] Step S604: determining a first temperature threshold according to the fourth pressure;

[0168] Step S606: Acquire a first temperature of a first temperature sensor;

[0169] Step S608: when the first temperature is higher than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is greater than or equal to the second temperature difference threshold, increasing the opening of the throttle valve;

[0170] Step S610: when the first temperature is lower than a first temperature threshold, and the difference between the first temperature and the first temperature threshold is smaller than a second temperature difference threshold, reducing the opening of the throttle valve;

[0171] Step S612: When the first temperature is higher than or equal to the first temperature threshold, and the difference between the first temperature and the first temperature threshold is less than the second temperature difference threshold, the opening of the throttle valve is kept unchanged.

[0172] In this design, a throttle valve is provided in the second heat exchange circuit of the air-conditioning system, and the throttle valve is provided at the inlet end of the fourth heat exchanger. The throttle valve is used to adjust the refrigerant flow at the inlet end of the fourth heat exchanger. It is understandable that the number of indoor units can be multiple, and the multiple indoor units can be respectively provided in environments with different temperatures. When the temperatures of the various environments are different, the refrigerant flow required for heat exchange by the fourth heat exchanger in the indoor unit is also different. By providing a throttle valve at the inlet end of the fourth heat exchanger, the flow of the refrigerant can be adjusted according to the actual heat exchange demand to improve the heat exchange efficiency. Specifically, the throttle valve adjusts the opening of the throttle valve according to the relationship between the temperature of the refrigerant in the current state and the saturation temperature under the current pressure state. It is understandable that under different pressures, the saturation temperature of the refrigerant is different. When the actual temperature of the refrigerant exceeds the saturation temperature, the heat exchange capacity of the refrigerant decreases.

[0173] In order to obtain the saturation temperature of the refrigerant under the current pressure state, a fourth pressure sensor is provided in the second heat exchange circuit, and specifically, the fourth pressure sensor is provided at the outlet end of the fourth heat exchanger. First, the fourth pressure is obtained by the fourth pressure sensor, and then the first temperature threshold corresponding to the detected fourth pressure is determined, that is, the saturation temperature of the refrigerant under the current pressure.

[0174] Furthermore, a first temperature sensor is provided in the second heat exchange circuit. Specifically, the first temperature sensor is provided at the outlet of the fourth heat exchanger, which is farther away from the outlet of the fourth heat exchanger than the fourth pressure sensor. The first temperature sensor detects the refrigerant temperature at the outlet of the fourth heat exchanger to obtain the first temperature.

[0175] Compare the first temperature with the first temperature threshold. When the first temperature is higher than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is greater than or equal to the second temperature difference threshold, it means that the refrigerant is insufficient at this time and the heat exchange efficiency cannot be guaranteed. The throttle valve opening is controlled to increase and the refrigerant flow rate is increased. When the first temperature is lower than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is less than the second temperature difference threshold, it means that the refrigerant is excessive at this time. The throttle valve opening is controlled to reduce and the refrigerant flow rate is reduced. When the first temperature is higher than or equal to the first temperature threshold, and the difference between the first temperature and the first temperature threshold is less than the second temperature difference threshold, it means that the refrigerant flow rate at this time just meets the use requirements. There is no need to adjust the refrigerant flow rate, and the throttle valve opening can be kept unchanged.

[0176] Specifically, the second temperature difference threshold is 2°C.

[0177] By comparing the first temperature with the first temperature threshold, and accurately controlling the throttle valve opening according to the comparison result, the refrigerant flow rate is adjusted to achieve the best cooling effect. By collecting the fourth pressure and the first temperature, and controlling the throttle valve opening according to the fourth pressure and the first temperature, the actual temperature of the refrigerant can be compared with the saturation temperature of the refrigerant under the current pressure state, and the throttle valve opening can be adjusted according to the comparison result to adjust the refrigerant flow rate, so as to improve the heat exchange efficiency of the air-conditioning system and reduce the energy consumption of the air-conditioning system.

[0178] Specific embodiments:

[0179] The present invention provides an air conditioning system 100 for a data center, which consists of two completely independent heat exchange circuits, one of which consists of a first heat exchanger 111, a third heat exchanger 121, connecting pipes and a control system, wherein the first heat exchanger 111 and the third heat exchanger 121 are heat pipe heat exchangers. The other heat exchange circuit consists of a second heat exchanger 112, a fourth heat exchanger 122, a compressor unit 113, connecting pipes and a control system. The air conditioning system 100 adopts a heat pipe heat exchange dual circulation technology and has the following advantages:

[0180] First, the operating principle of the air conditioning system 100 is that the heat pipe heat exchange loop is prioritized, that is, the indoor heat dissipation is first taken away by the heat pipe heat exchange loop, and the insufficient heat exchange is supplemented by the second heat exchange loop, that is, the compressor heat exchange loop. The specific implementation method is to set the third heat exchanger 121 at the front end of the return air of the indoor unit 120, and the fourth heat exchanger 122 is set at the rear end of the return air of the indoor unit 120, that is, to set the third heat exchanger 121 between the return air port 123 of the indoor unit 120 and the fourth heat exchanger 122. During operation, the air conditioning return air first passes through the third heat exchanger 121, that is, the heat pipe heat exchanger, and the return air is first cooled by the heat pipe heat exchanger and then passes through the fourth heat exchanger 122. The compressor heat exchange loop will automatically determine whether to turn on according to the return air temperature after the heat pipe heat exchange loop is cooled.

[0181] Secondly, the first heat exchange loop in the air-conditioning system 100 is a heat pipe heat exchange loop, which does not require any automatic control measures and can operate automatically as long as the indoor and outdoor temperature difference meets the heat pipe driving requirements. It has high reliability and strong energy saving.

[0182] In addition, when the first heat exchange circuit and the second heat exchange circuit operate together, the two heat exchange circuits are independent of each other and do not interfere with each other.

[0183] The start and stop control method of the compressor is as follows. The compressor is started according to the evaporation pressure of the compressor unit 113 in the second heat exchange circuit. The evaporation pressure is detected by the first pressure sensor 130 arranged at the return air port of the compressor unit 113. When the evaporation pressure Pe is greater than or equal to the first pressure threshold value Peps1, that is, the evaporation pressure Pe≥Peps1, and the delay reaches the first pressure detection time ts1, one of the compressors is started according to the wear balance. The wear balance ensures that the running time of each compressor is close, and the compressor with the shorter running time is started first. Among them, the default setting value of Peps1 is 12.5bar, and the recommended setting range is 7bar to 14bar. The default setting value of the first pressure detection time ts1 is 30s, and the recommended setting range is 1s to 180s.

[0184] The compressor is shut down according to the evaporation pressure value Pe and the delay condition. When the evaporation pressure Pe is less than the second pressure threshold value Peps2, that is, Pe<Peps2, and the delay reaches the second pressure detection time ts2, one of the compressors is shut down according to the wear balance, and the compressor with a longer running time is shut down first. Among them, the default setting value of Peps2 is 9.9bar, and the recommended setting range is 7bar to 14bar. The second pressure detection time ts2 defaults to 30s, and the recommended setting range is 1s to 180s.

[0185] During the operation of the compressor unit 113, the compressor is started and stopped according to the wear-balancing operation principle and the start-stop control logic.

[0186] The control method of the fan 160 is as follows. The fan 160 is controlled by the condensing pressure Pc of the second heat exchanger 112, the condensing pressure Pr of the first heat exchanger 111, the ambient temperature Tw, and the start / stop signal of the compressor unit 113. The condensing pressure Pc of the second heat exchanger 112 is detected by the third pressure sensor 150 disposed at the inlet end of the second heat exchanger 112, and the condensing pressure Pr of the first heat exchanger 111 is detected by the second pressure sensor 140 disposed at the inlet end of the first heat exchanger 111.

[0187] When the number of operating compressors is greater than or equal to one, the fan 160 is controlled to start and stop according to the condensing pressure Pc of the second heat exchanger 112.

[0188] When the compressor is not running, the fan 160 is controlled according to the condensing pressure Pr of the first heat exchanger 111, the loading pressure Prs2, the unloading pressure Prs3, and the delay ts5 to control the start and stop of the fan 160. Among them, the default setting value of Prs2 is 15.6bar, and the recommended setting range is 11.6bar to 20bar. The default setting value of Prs3 is 13.3bar, and the recommended setting range is 11.6bar to 15.7bar. The default setting value of delay ts5 is 3s, and the recommended setting range is 1s to 180s.

[0189] When the first heat exchange loop and the second heat exchange loop are working simultaneously, the fan 160 is controlled according to the method for controlling the fan 160 when the compressor is running.

[0190] The control method of the throttle valve 190 is as follows. The throttle valve 190 is controlled according to the superheat of the refrigerant at a single end. The superheat is set to 2°C by default and can be adjusted. The pressure P at the outlet of the fourth heat exchanger 122 and the corresponding refrigerant saturation temperature Tb are detected, and the actual temperature T of the refrigerant is compared with Tb. When T-Tb≥2, the opening of the throttle valve 190 is increased until T-Tb<2, and the opening is kept unchanged.

[0191] In the present invention, the term "plurality" refers to two or more than two, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0192] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0193] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control method for an air conditioning system, characterized in that: The air conditioning system comprises: an outdoor unit, the outdoor unit comprises a first heat exchanger, a second heat exchanger and a compressor unit; at least one indoor unit, the indoor unit comprises: a third heat exchanger, a fourth heat exchanger, a return air port and an air outlet, the third heat exchanger is located between the fourth heat exchanger and the return air port; the first heat exchanger and the third heat exchanger are connected end to end to form a first heat exchange loop; the second heat exchanger, the fourth heat exchanger and the compressor unit are connected end to end in sequence to form a second heat exchange loop; wherein the first heat exchange loop and the second heat exchange loop operate independently of each other, the first heat exchanger and the third heat exchanger are both heat pipe heat exchangers; the third heat exchanger and the fourth heat exchanger are arranged in parallel; the air conditioning system further comprises: a first pressure sensor, which is arranged on the second heat exchange loop The first pressure sensor is located at the return air port of the compressor unit; the second pressure sensor is arranged in the first heat exchange circuit, and the second pressure sensor is located at the inlet end of the first heat exchanger; the third pressure sensor is arranged in the second heat exchange circuit, and the third pressure sensor is located at the inlet end of the second heat exchanger; the outdoor unit also includes at least one fan; the air conditioning system also includes: a first temperature sensor, arranged in the second heat exchange circuit, and the first temperature sensor is located at the outlet end of the fourth heat exchanger; a fourth pressure sensor, arranged in the second heat exchange circuit, and the fourth pressure sensor is located between the fourth heat exchanger and the first temperature sensor; a throttle valve, arranged in the second heat exchange circuit, and the throttle valve is located at the inlet end of the fourth heat exchanger; The control method of the air conditioning system comprises: In response to a startup operation instruction, obtaining a target temperature; Based on the return air temperature of the indoor unit being higher than the outdoor ambient temperature, and the difference between the return air temperature and the outdoor ambient temperature being greater than a first temperature difference threshold, the first heat exchange circuit performs heat exchange; Acquire a first pressure of the first pressure sensor, and control the compressor unit to operate according to the first pressure and the target temperature; After controlling the compressor unit to work, the method further comprises: Acquiring a fourth pressure from the fourth pressure sensor; determining a first temperature threshold according to the fourth pressure; Acquire a first temperature of the first temperature sensor; When the first temperature is higher than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is greater than or equal to a second temperature difference threshold, increasing the opening of the throttle valve; When the first temperature is lower than the first temperature threshold, and the difference between the first temperature and the first temperature threshold is smaller than the second temperature difference threshold, reducing the opening of the throttle valve; When the first temperature is higher than or equal to the first temperature threshold, and the difference between the first temperature and the first temperature threshold is smaller than the second temperature difference threshold, the opening of the throttle valve is kept unchanged.

2. The control method of the air conditioning system according to claim 1, characterized in that: The step of controlling the compressor unit to operate according to the first pressure and the target temperature specifically includes: determining a first pressure threshold according to the target temperature; When the first pressure is greater than or equal to the first pressure threshold, starting a compressor in the compressor group; At a first preset time interval, when the first pressure is greater than or equal to the first pressure threshold, increasing the number of compressors in the compressor group to be started; When the first pressure is less than a second pressure threshold, reducing the number of startups of the compressors in the compressor group; The second pressure threshold is lower than the first pressure threshold.

3. The control method of the air conditioning system according to claim 1, characterized in that: Before controlling the compressor unit to work, the method further includes: acquiring a second pressure of the second pressure sensor; When the second pressure is greater than or equal to a third pressure threshold, starting one of the fans; At a second preset time interval, when the second pressure is greater than or equal to the third pressure threshold, increasing the number of starts of the fan; When the second pressure is less than a fourth pressure threshold, the number of starts of the fan is reduced.

4. The control method of the air conditioning system according to claim 3, characterized in that: After controlling the compressor unit to work, the method further comprises: Acquiring a third pressure of the third pressure sensor; When the third pressure is greater than or equal to a fifth pressure threshold, increasing the number of starts of the fan; When the third pressure value is less than a sixth pressure threshold, the number of starts of the fan is reduced.

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