Air conditioning system

Abstract

The invention provides an air conditioning system. The air conditioning system comprises a condenser and a plurality of compressors, the number of the refrigerant branches is the same as that of the compressors, the compressors are connected with the condenser through the refrigerant branches so that refrigerants can flow to the compressors through the refrigerant branches to cool the compressors and frequency converters of the compressors, and each refrigerant branch is provided with a one-way valve. And the pump front end of the refrigerant pump is connected with the multiple refrigerant branches in parallel at the valve front end of the one-way valve, and the pump rear end of the refrigerant pump is connected with the multiple refrigerant branches at the valve rear end of the one-way valve through the multiple pump rear branches. The refrigerant pump can be used for conveying refrigerants to the multiple compressors at the same time, and the conveying capacity of the refrigerant pump can be more fully utilized.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to an air conditioning system. Background Technology

[0002] In existing large-scale air conditioning systems, because the operating temperatures of the compressor and inverter can reach very high levels, an additional refrigerant line is typically installed on the compressor. This additional refrigerant line connects to the condenser, utilizing the pressure difference between the compressor's suction port and the condenser to force the refrigerant into this line. The refrigerant in this line cools the compressor and inverter before entering the suction port to continue circulating in the air conditioning system. However, because sometimes the pressure difference from the compressor may be insufficient to force the refrigerant into the refrigerant line, a refrigerant pump is usually installed on the refrigerant line to ensure a reliable refrigerant supply. Summary of the Invention

[0003] One object of the present invention is to provide an air conditioning system that enables more efficient use of the refrigerant pump's delivery flow rate.

[0004] A further objective of this invention is to help improve the service life of refrigerant pumps.

[0005] Specifically, the present invention provides an air conditioning system, comprising:

[0006] Condenser and multiple compressors;

[0007] Multiple refrigerant branches, the number of which is the same as the number of compressors, are provided. Each compressor is connected to the condenser via one of these refrigerant branches, allowing refrigerant to flow to each compressor to cool the compressors and their inverters. Each refrigerant branch is equipped with a one-way valve.

[0008] A refrigerant pump, wherein the pump front end of the refrigerant pump is connected in parallel with multiple refrigerant branches at the valve front end of a one-way valve, and the pump rear end of the refrigerant pump is connected to multiple refrigerant branches at the valve rear end of the one-way valve through multiple pump rear branches.

[0009] Optionally, each of the downstream branches is provided with a branch valve to control the on / off state of the corresponding downstream branch.

[0010] Optionally, the refrigerant pump is configured to start when preset start-up conditions are met.

[0011] Optionally, the preset start-up conditions include that the temperature of the inverter of at least one of the compressors corresponding to the refrigerant pump is greater than or equal to a first temperature threshold and the duration is greater than or equal to a first time threshold.

[0012] Optionally, the preset start-up conditions also include that the speed of all the compressors corresponding to the refrigerant pump is greater than or equal to a preset speed threshold and the duration is greater than or equal to a second time threshold.

[0013] Optionally, the preset start-up conditions also include the liquid level of the condenser being greater than a preset liquid level threshold and the duration being greater than or equal to a third time threshold.

[0014] Optionally, the preset start-up condition also includes the refrigerant pump's downtime being greater than or equal to a fourth time threshold.

[0015] Optionally, the refrigerant pump is configured to shut down when all corresponding compressors have stopped.

[0016] Optionally, the refrigerant pump is configured to shut down when the temperature of the inverters of all the corresponding compressors is less than or equal to a second temperature threshold and the duration is greater than or equal to a fifth time threshold, and the operating time of the refrigerant pump meets a preset minimum operating time.

[0017] Optionally, the refrigerant pump is configured to shut down if the refrigerant pump's operating time is greater than or equal to a preset maximum operating time.

[0018] Optionally, the air conditioning system is provided with a first pressure sensor for detecting the post-pump pressure of the refrigerant pump and a second pressure sensor for detecting the cylinder pressure of the condenser;

[0019] The air conditioning system is configured to determine that the refrigerant pump is faulty if the difference between the detection value of the first pressure sensor and the detection value of the second pressure sensor is less than or equal to a first pressure threshold and the duration is greater than or equal to a sixth time threshold.

[0020] Optionally, the conditions for the air conditioning system to determine that the refrigerant pump is faulty also include that the duration of the refrigerant pump being in the on state is greater than or equal to a seventh time threshold, and that the detection value of the second pressure sensor is less than or equal to a second pressure threshold and the duration is greater than or equal to an eighth time threshold.

[0021] Optionally, the air conditioning system further includes a return branch, the inlet end of which is connected to the rear end of the refrigerant pump, and the connection position is located before all the post-pump branches. The outlet end of the return branch is connected to the condenser. The return branch is provided with a pressure regulating valve to allow a portion of the refrigerant to flow back to the condenser when the post-pump pressure of the refrigerant pump exceeds the set value of the pressure regulating valve.

[0022] Optionally, the air conditioning system is configured to determine that the pressure regulating valve is faulty if the difference between the detection value of the first pressure sensor and the detection value of the second pressure sensor is greater than or equal to a third pressure threshold and the duration for which the refrigerant pump is in the on state is greater than or equal to a ninth time threshold.

[0023] The air conditioning system of this invention uses multiple compressors, each connected to a condenser via multiple refrigerant branches. The front end of the refrigerant pump is connected in parallel to the front end of the check valves of the multiple refrigerant branches, and the rear end of the refrigerant pump is connected to the rear end of the check valves of the multiple refrigerant branches via multiple post-pump branches. After the refrigerant pump starts, the pressure at the front end of the check valve of each refrigerant branch is greater than the pressure at the rear end, causing the check valve to close. Refrigerant flows to the refrigerant pump, then through the multiple post-pump branches into the corresponding refrigerant branches, and finally along each refrigerant branch to the corresponding compressor, thereby cooling all compressors and their inverters. Therefore, a single refrigerant pump can simultaneously supply refrigerant to multiple compressors; that is, the delivery capacity of one refrigerant pump can meet the needs of multiple compressors, thus ensuring the cooling effect of the compressors while making fuller use of the refrigerant pump's delivery capacity. Furthermore, using multiple compressors in the air conditioning system also helps to improve the system's power conversion efficiency.

[0024] Furthermore, the air conditioning system of the present invention configures the refrigerant pump to start when preset start-up conditions are met. These preset start-up conditions include: the temperature of the inverter of at least one compressor corresponding to the refrigerant pump being greater than or equal to a first temperature threshold for a duration greater than or equal to a first time threshold; the rotational speed of all compressors corresponding to the refrigerant pump being greater than or equal to a preset rotational speed threshold for a duration greater than or equal to a second time threshold; the liquid level of the condenser being greater than a preset liquid level threshold for a duration greater than or equal to a third time threshold; and the shutdown time of the refrigerant pump being greater than or equal to a fourth time threshold. This ensures that the refrigerant pump starts only when needed, avoiding accidental start-up caused by the compressor being in the start-up or shutdown phase. It also prevents damage to the refrigerant pump due to the condenser liquid level not meeting the preset liquid level threshold, and avoids overworking the refrigerant pump. This guarantees the normal operating time and conditions of the refrigerant pump, thus contributing to an increase in its service life.

[0025] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0026] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0027] Figure 1 This is a schematic diagram of an air conditioning system according to an embodiment of the present invention;

[0028] Figure 2 This is a partial schematic diagram of an air conditioning system according to an embodiment of the present invention.

[0029] Figure 3 This is a schematic flowchart of a control method for an air conditioning system according to an embodiment of the present invention. Detailed Implementation

[0030] Those skilled in the art should understand that the embodiments described below are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. These partial embodiments are intended to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those skilled in the art without creative effort should still fall within the scope of protection of the present invention.

[0031] It should be noted that, in the description of this invention, each functional module can be a physical module composed of multiple structures, components, or electronic devices, or a virtual module composed of multiple programs; each functional module can be an independent module or a module divided from a whole module according to its function. Those skilled in the art should understand that, provided the technical solution described in this invention can be implemented, any changes in the configuration, implementation, or positional relationship of the functional modules will not deviate from the technical principles of this invention, and therefore should all fall within the protection scope of this invention.

[0032] like Figure 1As shown, in one embodiment, the air conditioning system includes two compressors 100, a condenser 200, an evaporator 300, and an expansion valve 400. Specifically, each of the two compressors 100 has a pipe leading to the condenser 200. The condenser 200 has a pipe leading to the evaporator 300, and the expansion valve 400 is located on the pipe connecting the condenser 200 and the evaporator 300. The evaporator 300 has pipes leading to both compressors 100. That is, the two compressors 100 can respectively deliver refrigerant to the condenser 200 through two pipes. The refrigerant in the condenser 200 is delivered to the evaporator 300 through the pipe leading to the evaporator 300, passing through the expansion valve 400. The refrigerant in the evaporator 300 then flows back to the two compressors 100 through the two pipes. It can be understood that the air conditioning system of this embodiment has two compressors 100 driving the refrigerant circulation, improving heat exchange efficiency.

[0033] like Figure 1 and Figure 2 As shown, the air conditioning system also includes two refrigerant branches 11 and a refrigerant pump 500. The number of refrigerant branches 11 is the same as the number of compressors 100. The two compressors 100 are connected to the condenser 200 via the two refrigerant branches 11, so that the refrigerant flows to the two compressors 100 via the two refrigerant branches 11 to cool the compressors 100 and their inverters. Each refrigerant branch 11 is equipped with a one-way valve 600. The pump front end of the refrigerant pump 500 is connected in parallel with the valve front end of the two refrigerant branches 11 at the one-way valve 600, and the pump rear end of the refrigerant pump 500 is connected to the valve rear end of the two refrigerant branches 11 via two post-pump branches 12.

[0034] Reference Figure 1 and Figure 2 As shown, specifically, the condenser 200 is connected to a main refrigerant outlet, which branches into two refrigerant branches 11. The two refrigerant branches 11 are respectively connected to two compressors 100. Each of the two refrigerant branches 11 is equipped with a one-way valve 600, which allows the refrigerant in the condenser 200 to enter the main refrigerant outlet, and then be divided into two refrigerant streams that enter the two refrigerant branches 11 respectively, and then flow along the refrigerant branches 11 to the corresponding compressors 100, thereby cooling the compressors 100 and their inverters.

[0035] Continue to refer to Figure 1 and Figure 2As shown, the front end of the refrigerant pump 500 is connected to the main refrigerant outlet, thus connecting the refrigerant pump 500 in parallel with all refrigerant branches 11. The rear end of the refrigerant pump 500 is connected to the two refrigerant branches 11 via two downstream branches 12 at the rear end of the one-way valve 600. Therefore, when the refrigerant pump 500 starts, the pressure at the rear end of the one-way valve 600 is greater than the pressure at the front end, causing the one-way valve 600 to close. Thus, all the refrigerant in the main refrigerant outlet flows through the refrigerant pump 500, then splits into two paths flowing from the two downstream branches 12 to the corresponding refrigerant branches 11, and then along the refrigerant branches 11 to the corresponding compressor 100, thereby cooling the compressor 100 and its inverter.

[0036] It should be noted that in some other embodiments, the condenser may also be directly connected to multiple compressors via multiple branches, and the refrigerant pump needs to be connected to the position before the check valve of multiple branches via multiple pre-pump branches, and to the position after the check valve of multiple branches via multiple post-pump branches.

[0037] In a typical scenario where one refrigerant pump corresponds to one compressor, the refrigerant pump's delivery capacity is far greater than the compressor's required capacity, resulting in design redundancy in the refrigerant pump.

[0038] The air conditioning system in this embodiment uses multiple compressors 100, each connected to a condenser 200 via multiple refrigerant branches 11. The front end of a refrigerant pump 500 is connected in parallel with the front end of a one-way valve 600 along each of the refrigerant branches 11. The rear end of the refrigerant pump 500 is connected to the rear end of each of the one-way valves 600 via multiple post-pump branches. When the refrigerant pump 500 starts, the pressure at the front end of the one-way valve 600 in each refrigerant branch 11 is greater than the pressure at the rear end, causing the one-way valve 600 to close. Refrigerant flows to the refrigerant pump 500, then enters the corresponding refrigerant branch 11 via multiple post-pump branches 12, and finally flows along each refrigerant branch 11 to the corresponding compressor 100, thereby cooling all compressors 100 and their inverters.

[0039] Therefore, a single refrigerant pump 500 can simultaneously supply refrigerant to multiple compressors 100. In other words, the delivery capacity of one refrigerant pump 500 can meet the needs of multiple compressors 100, thus ensuring the cooling effect of the compressors 100 while making fuller use of the refrigerant pump 500's delivery capacity. Furthermore, having multiple compressors 100 in the air conditioning system also helps improve the system's efficiency.

[0040] It should be noted that in some other embodiments, the number of compressors in the air conditioning system may also be three, four or more, as long as the refrigerant pump's delivery capacity can meet the needs of all compressors.

[0041] Additionally, it should be noted that in some other embodiments, the air conditioning system may also be configured with a combination of multiple refrigerant pumps and multiple compressors. That is, the air conditioning system may include multiple refrigerant pumps, and each refrigerant pump corresponds to multiple compressors.

[0042] like Figure 1 and Figure 2 As shown, each downstream branch 12 is further equipped with a branch valve 700 to control the on / off state of the corresponding downstream branch 12. Specifically, the branch valve 700 is a solenoid valve. After the refrigerant pump 500 starts, if the branch valve 700 of the downstream branch 12 is also opened, refrigerant can flow from the downstream branch 12 to the corresponding refrigerant branch 11. If the branch valve 700 of the downstream branch 12 is closed, refrigerant cannot flow to the corresponding refrigerant branch 11. By setting a branch valve 700 in each downstream branch 12, the on / off state of the corresponding downstream branch 12 can be controlled by the branch valve 700, thereby more flexibly controlling the refrigerant supply from the refrigerant pump 500 to the required compressor 100.

[0043] Reference Figure 1 and Figure 2 As shown, the refrigerant pump 500 is configured to start under preset start-up conditions. The preset start-up conditions include: the temperature of the inverter of at least one compressor 100 corresponding to the refrigerant pump 500 is greater than or equal to a first temperature threshold for a duration greater than or equal to a first time threshold; the speed of all compressors 100 corresponding to the refrigerant pump 500 is greater than or equal to a preset speed threshold for a duration greater than or equal to a second time threshold; the liquid level of the condenser 200 is greater than a preset liquid level threshold for a duration greater than or equal to a third time threshold; and the shutdown time of the refrigerant pump 500 is greater than or equal to a fourth time threshold.

[0044] Specifically, the preset start-up conditions are only met when all the above conditions are satisfied. If the temperature of the inverter in compressor 100 is greater than or equal to the first temperature threshold and the duration is greater than or equal to the first time threshold, meaning the inverter temperature in compressor 100 is high and maintained for a certain period, it indicates that the current cooling effect is poor. This may be due to insufficient pressure differential in compressor 100, resulting in insufficient or no refrigerant flowing to compressor 100 for cooling. Therefore, it is necessary to start refrigerant pump 500 to deliver refrigerant for cooling to compressor 100.

[0045] Simultaneously, it is also necessary to determine that the rotational speed of all compressors 100 corresponding to refrigerant pump 500 is greater than or equal to a preset speed threshold and the duration is greater than or equal to a second time threshold. Specifically, the second time threshold is less than the first time threshold. That is, within the first time threshold period, the rotational speed of compressor 100 must be greater than or equal to the preset speed threshold and the duration must be greater than or equal to the second time threshold to determine that compressor 100 is in normal working condition. This is because if compressor 100 is in the start-up phase, its rotational speed is gradually increasing. Before the rotational speed reaches the working requirements, it is normal for the pressure difference of compressor 100 not to meet the requirements. Alternatively, if compressor 100 is in the shutdown phase, its rotational speed is slowly decreasing. In other words, compressor 100 is about to stop working, which means the air conditioning system is about to stop working. In this case, the temperature of the inverter of compressor 100 will drop after it stops working. Moreover, since the air conditioning system stops working, turning on refrigerant pump 500 is useless. Therefore, the condition for turning on refrigerant pump 500 is that the rotational speed of all compressors 100 corresponding to refrigerant pump 500 is greater than or equal to the preset speed threshold and the duration must be greater than or equal to the second time threshold.

[0046] Furthermore, it is also necessary to determine that the liquid level in the condenser 200 is greater than a preset liquid level threshold and the duration is greater than or equal to a third time threshold. Specifically, the third time threshold is less than the first time threshold, meaning that within the first time threshold period, the liquid level in the condenser 200 is greater than the preset liquid level threshold and the duration is greater than or equal to the third time threshold. This is because if the liquid level in the condenser 200 does not meet the preset liquid level threshold, the refrigerant pump 500 will not be able to draw in enough refrigerant, which may damage the refrigerant pump 500.

[0047] In addition, it is necessary to determine that the downtime of the refrigerant pump 500 is greater than or equal to the fourth time threshold. Specifically, the refrigerant pump 500 starts timing after each shutdown to record the shutdown time of the refrigerant pump 500. This ensures that there is a sufficient time interval between two start-up actions of the refrigerant pump 500 to avoid overworking the refrigerant pump 500 and affecting its service life.

[0048] In this embodiment, the refrigerant pump 500 is configured to start only when preset start-up conditions are met. These preset start-up conditions include that the temperature of the inverter of at least one compressor 100 corresponding to the refrigerant pump 500 is greater than or equal to a first temperature threshold for a duration greater than or equal to a first time threshold, and the speed of all compressors 100 corresponding to the refrigerant pump 500 is greater than or equal to a preset speed threshold for a duration greater than or equal to a second time threshold. In other words, the refrigerant pump 500 only starts when the temperature of the inverter of at least one corresponding compressor 100 is greater than or equal to the first temperature threshold for a duration greater than or equal to the first time threshold, and the speed of all compressors 100 corresponding to the refrigerant pump 500 is greater than or equal to the preset speed threshold for a duration greater than or equal to the second time threshold. This avoids starting the refrigerant pump 500 when the compressor 100 is in the start-up phase, before the required pressure difference is reached, thus preventing wasted power. It also avoids starting the refrigerant pump 500 when the compressor 100 is in the shutdown phase, preventing it from functioning at all.

[0049] Furthermore, by ensuring that the preset start-up conditions of the refrigerant pump 500 also simultaneously meet the requirement that the liquid level of the condenser 200 is greater than the preset liquid level threshold and the duration is greater than or equal to the third time threshold, it is possible to prevent the refrigerant pump 500 from being unable to draw in enough refrigerant due to the liquid level of the condenser 200 not meeting the preset liquid level threshold, which could lead to damage to the refrigerant pump 500.

[0050] In addition, by ensuring that the preset start-up conditions of the refrigerant pump 500 also meet the requirement that the shutdown time of the refrigerant pump 500 is greater than or equal to the fourth time threshold, it helps to prevent the refrigerant pump 500 from starting too frequently, thereby preventing the refrigerant pump 500 from overworking and affecting its service life.

[0051] It should be noted that in some other embodiments, the preset start-up conditions may only include the inverter temperature of at least one compressor 100 corresponding to the refrigerant pump 500 being greater than or equal to a first temperature threshold and the duration being greater than or equal to a first time threshold, and at least one of the other three conditions. Preferably, the liquid level of the condenser 200 being greater than a preset liquid level threshold and the duration being greater than or equal to a third time threshold are selected as conditions that must be met simultaneously; next preferably, the rotational speed of all compressors 100 corresponding to the refrigerant pump 500 being greater than or equal to a preset rotational speed threshold and the duration being greater than or equal to a second time threshold are selected as conditions that must be met simultaneously; and least preferably, the shutdown time of the refrigerant pump 500 being greater than or equal to a fourth time threshold are selected as conditions that must be met simultaneously.

[0052] Reference Figure 1 and Figure 2As shown, the refrigerant pump 500 is further configured to shut down when all corresponding compressors 100 are stopped. Alternatively, the refrigerant pump 500 is configured to shut down when the temperature of the inverters of all corresponding compressors 100 is less than or equal to a second temperature threshold and the duration is greater than or equal to a fifth time threshold, and the operating time of the refrigerant pump 500 meets a preset minimum operating time. Alternatively, the refrigerant pump 500 is configured to shut down when the operating time of the refrigerant pump 500 is greater than or equal to a preset maximum operating time.

[0053] Specifically, when all compressors 100 corresponding to refrigerant pump 500 have stopped, that is, when the air conditioning system stops working, it is useless to turn refrigerant pump 500 back on. Therefore, refrigerant pump 500 can be turned off at this time.

[0054] Alternatively, when the temperature of the inverters of all compressors 100 corresponding to refrigerant pump 500 is less than or equal to the second temperature threshold and the duration is greater than or equal to the fifth time threshold, it indicates that the inverters of compressors 100 have dropped to the required temperature, and refrigerant pump 500 can be shut down. Simultaneously, it is determined that the operating time of refrigerant pump 500 meets the preset minimum operating time. That is, even if the temperature of the inverters of all compressors 100 corresponding to refrigerant pump 500 is less than or equal to the second temperature threshold and the duration is greater than or equal to the fifth time threshold, but the operating time of refrigerant pump 500 has not yet reached the preset minimum operating time, refrigerant pump 500 cannot be shut down; instead, refrigerant pump 500 remains on until the preset minimum operating time is reached.

[0055] By configuring the refrigerant pump 500 to shut down when the temperature of the inverters of all corresponding compressors 100 is less than or equal to a second temperature threshold and the duration is greater than or equal to a fifth time threshold, and the operating time of the refrigerant pump 500 meets the preset minimum operating time, that is, even if the inverter of the compressor 100 drops to the required temperature, but the operating time of the refrigerant pump 500 has not yet reached the preset minimum operating time, the refrigerant pump 500 cannot be shut down, but will continue to be kept on until the preset minimum operating time is reached. This can further reduce the temperature of the inverter of the compressor 100, allowing the inverter of the compressor 100 to maintain a lower temperature for a longer period of time, thereby avoiding the frequent start-stop of the refrigerant pump 500 which would affect the service life of the refrigerant pump 500.

[0056] Alternatively, if the running time of refrigerant pump 500 is greater than or equal to the preset maximum running time, it indicates that the working pressure of refrigerant pump 500 is already very high. In this case, refrigerant pump 500 will also be shut down to avoid malfunction.

[0057] Reference Figure 3 As shown, the above content will be further explained with reference to the schematic flowchart, such as... Figures 1 to 3 As shown, the control methods for air conditioning systems generally include the following during operation:

[0058] Step S301: Obtain the temperature of the compressor's inverter. Specifically, this means monitoring the temperature of the inverters of both compressors 100 in real time.

[0059] Step S302: Determine whether the temperature of the frequency converter is greater than or equal to the first temperature threshold. If yes, proceed to step S303; otherwise, proceed to step S308.

[0060] Step S303: Start recording time and detect the compressor speed and condenser liquid level. Specifically, start recording time from the moment the temperature of the compressor 100's inverter is detected to be greater than or equal to a first temperature threshold. Simultaneously, continuously detect the compressor 100's speed and the condenser 200's liquid level.

[0061] Step S304: Determine whether the duration for which the inverter's temperature is greater than or equal to the first temperature threshold is greater than the first time threshold. If yes, proceed to step S305; otherwise, proceed to step S308.

[0062] Step S305: Determine whether the compressor speed and condenser liquid level meet the conditions. If yes, proceed to step S306; otherwise, proceed to step S308. Specifically, this means determining whether, within the time period of the first time threshold, the speed of all compressors 100 corresponding to the refrigerant pump 500 is greater than or equal to a preset speed threshold and the duration is greater than or equal to a second time threshold, and whether the liquid level of the condenser 200 is greater than a preset liquid level threshold and the duration is greater than or equal to a third time threshold.

[0063] Step S306: Determine whether the refrigerant pump's downtime is greater than or equal to the fourth time threshold. If yes, proceed to step S307; otherwise, proceed to step S308. Specifically, the downtime of refrigerant pump 500 is recorded each time it stops.

[0064] Step S307: Control the refrigerant pump to start. Specifically, the refrigerant pump 500 is started when the following conditions are met: the temperature of the inverter of at least one compressor 100 corresponding to the refrigerant pump 500 is greater than or equal to a first temperature threshold and the duration is greater than or equal to a first time threshold; the speed of all compressors 100 corresponding to the refrigerant pump 500 is greater than or equal to a preset speed threshold and the duration is greater than or equal to a second time threshold; the liquid level of the condenser 200 is greater than a preset liquid level threshold and the duration is greater than or equal to a third time threshold; and the shutdown time of the refrigerant pump 500 is greater than or equal to a fourth time threshold.

[0065] Step S308: Keep the refrigerant pump off. Specifically, if any of the following conditions are not met: the temperature of the inverter of at least one compressor 100 corresponding to the refrigerant pump 500 is greater than or equal to a first temperature threshold and the duration is greater than or equal to a first time threshold; the speed of all compressors 100 corresponding to the refrigerant pump 500 is greater than or equal to a preset speed threshold and the duration is greater than or equal to a second time threshold; the liquid level of the condenser 200 is greater than a preset liquid level threshold and the duration is greater than or equal to a third time threshold; or the shutdown time of the refrigerant pump 500 is greater than or equal to a fourth time threshold, the refrigerant pump 500 is kept off.

[0066] Furthermore, during the use of the air conditioning system, after the refrigerant pump 500 starts, the control method of the air conditioning system generally includes: detecting whether the shutdown conditions have been met. The shutdown conditions are: all compressors 100 corresponding to the refrigerant pump 500 stop; the temperature of the inverters of all compressors 100 corresponding to the refrigerant pump 500 is less than or equal to a second temperature threshold and the duration is greater than or equal to a fifth time threshold, and the running time of the refrigerant pump 500 meets a preset minimum running time; or the running time of the refrigerant pump 500 is greater than or equal to a preset maximum running time. If yes, the refrigerant pump is controlled to shut down; otherwise, the refrigerant pump remains on.

[0067] Reference Figure 1 and Figure 2 As shown, the air conditioning system further includes a first pressure sensor 20 for detecting the post-pump pressure of the refrigerant pump 500 and a second pressure sensor 30 for detecting the cylinder pressure of the condenser 200. The air conditioning system is configured to determine a refrigerant pump 500 malfunction when the difference between the detected value of the first pressure sensor 20 and the detected value of the second pressure sensor 30 is less than or equal to a first pressure threshold and the duration is greater than or equal to a sixth time threshold.

[0068] Specifically, the difference between the detection value of the first pressure sensor 20 and the detection value of the second pressure sensor 30 is the value obtained by subtracting the detection value of the second pressure sensor 30 from the detection value of the first pressure sensor 20. If the difference between the detection value of the first pressure sensor 20 and the detection value of the second pressure sensor 30 is less than the first pressure threshold and the duration is greater than or equal to the sixth time threshold, it indicates that the refrigerant pump cannot provide sufficient pressure for a long time, and the refrigerant pump 500 is determined to have malfunctioned.

[0069] Furthermore, the conditions for the air conditioning system to determine that the refrigerant pump 500 is faulty also include determining that the duration for which the refrigerant pump 500 is in the on state is greater than or equal to the seventh time threshold, and that the detection value of the second pressure sensor 30 is less than or equal to the second pressure threshold for a duration greater than or equal to the eighth time threshold. Specifically, determining that the duration for which the refrigerant pump 500 is in the on state is greater than or equal to the seventh time threshold means determining that the refrigerant pump 500 is in normal working condition, because if the refrigerant pump 500 is in the initial startup state, the pressure after the pump will not reach the required level. Therefore, it is necessary to ensure that the refrigerant pump 500 has been running for a sufficient period of time and has entered normal working condition. At the same time, this also allows the first pressure sensor 20 time to stabilize its response.

[0070] In addition, in some cases, the pressure in the condenser 200 cylinder may be very high. Even if the refrigerant pump 500 is working normally, it may not meet the requirement that the difference between the detection value of the first pressure sensor 20 and the detection value of the second pressure sensor 30 is greater than or equal to the first pressure threshold. Therefore, it is determined that the detection value of the second pressure sensor 30 is less than or equal to the second pressure threshold and the duration is greater than or equal to the eighth time threshold, so as to avoid the condenser 200 being in a special situation of excessive pressure, which could lead to misjudgment of the fault.

[0071] By installing a first pressure sensor 20 for detecting the post-pump pressure of the refrigerant pump 500 and a second pressure sensor 30 for detecting the cylinder pressure of the condenser 200 in the air conditioning system, the air conditioning system is configured to determine a refrigerant pump 500 malfunction when the difference between the detected value of the first pressure sensor 20 and the detected value of the second pressure sensor 30 is less than or equal to a first pressure threshold and the duration is greater than or equal to a sixth time threshold. This allows for timely detection of refrigerant pump 500 malfunctions and timely maintenance of the refrigerant pump 500.

[0072] In addition, the conditions for determining a fault in the refrigerant pump 500 also include determining that the duration of the refrigerant pump 500 being in the on state is greater than or equal to the seventh time threshold, and that the detection value of the second pressure sensor 30 is less than or equal to the second pressure threshold and the duration is greater than or equal to the eighth time threshold. This ensures that the refrigerant pump 500 has entered a normal working state when a fault is determined and avoids the special situation of the condenser 200 being under excessive pressure, thereby reducing the occurrence of misjudgments.

[0073] like Figure 1 and Figure 2 As shown, the air conditioning system also includes a return branch 13. The inlet end of the return branch 13 is connected to the rear end of the refrigerant pump 500, and the connection position is located before all the post-pump branches 12. The outlet end of the return branch 13 is connected to the condenser 200. The return branch 13 is equipped with a pressure regulating valve 800 to allow part of the refrigerant to flow back to the condenser 200 when the post-pump pressure of the refrigerant pump 500 exceeds the set value of the pressure regulating valve 800.

[0074] Specifically, by setting up a return branch 13, the inlet end of the return branch 13 is connected to the rear end of the refrigerant pump 500, and the connection position is located before all the post-pump branches 12. The outlet end of the return branch 13 is connected to the condenser 200. A pressure regulating valve 800 is provided in the return branch 13, so that when the post-pump pressure of the refrigerant pump 500 exceeds the set value of the pressure regulating valve 800, part of the refrigerant is returned to the condenser 200. That is, when the pressure provided by the refrigerant pump 500 is higher than the pressure of the refrigerant port of the compressor 100, the pressure of the refrigerant port of the compressor 100 is made up to meet the requirements by allowing part of the refrigerant to flow back to the condenser 200.

[0075] Reference Figure 1 and Figure 2 As shown, the air conditioning system is configured to determine that the pressure regulating valve 800 is faulty when the difference between the detection values ​​of the first pressure sensor 20 and the second pressure sensor 30 is greater than or equal to a third pressure threshold and the refrigerant pump is in the on state for a duration greater than or equal to a ninth time threshold. Specifically, if the difference between the detection values ​​of the first pressure sensor 20 and the second pressure sensor 30 is greater than or equal to the third pressure threshold, it indicates that the pressure relief function of the return branch 13 is ineffective, suggesting that the pressure regulating valve 800 may be faulty. Furthermore, simultaneously determining that the refrigerant pump is in the on state for a duration greater than or equal to the ninth time threshold confirms that the refrigerant pump 500 is in normal working condition, ensuring the accuracy of the judgment.

[0076] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus or device (such as a computer-based system, a processor-included system or other system that can fetch and execute instructions from, an instruction execution system, apparatus or device).

[0077] The flowchart provided in this embodiment is not intended to indicate that the operations of the method will be performed in any particular order, or that all operations of the method are included in every case. Furthermore, the method may include additional operations. Within the scope of the technical concept provided by the method in this embodiment, additional variations can be made to the above method.

[0078] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. An air conditioning system, comprising: Condenser and multiple compressors; Multiple refrigerant branches, the number of which is the same as the number of compressors, are provided. Each compressor is connected to the condenser via one of these refrigerant branches, allowing refrigerant to flow to each compressor to cool the compressors and their inverters. Each refrigerant branch is equipped with a one-way valve. A refrigerant pump, wherein the pump front end of the refrigerant pump is connected in parallel with multiple refrigerant branches at the valve front end of a one-way valve, and the pump rear end of the refrigerant pump is connected to multiple refrigerant branches at the valve rear end of the one-way valve through multiple pump rear branches.

2. The air conditioning system according to claim 1, wherein, Each of the downstream branches is equipped with a branch valve to control the on / off state of the corresponding downstream branch.

3. The air conditioning system according to claim 1, wherein, The refrigerant pump is configured to start when preset start-up conditions are met.

4. The air conditioning system according to claim 3, wherein, The preset start-up conditions include that the temperature of the inverter of at least one of the compressors corresponding to the refrigerant pump is greater than or equal to a first temperature threshold and the duration is greater than or equal to a first time threshold.

5. The air conditioning system according to claim 4, wherein, The preset start-up conditions also include that the speed of all compressors corresponding to the refrigerant pump is greater than or equal to a preset speed threshold and the duration is greater than or equal to a second time threshold.

6. The air conditioning system according to claim 5, wherein, The preset start-up conditions also include that the liquid level of the condenser is greater than a preset liquid level threshold and the duration is greater than or equal to a third time threshold.

7. The air conditioning system according to claim 6, wherein, The preset start-up conditions also include the refrigerant pump's downtime being greater than or equal to a fourth time threshold.

8. The air conditioning system according to claim 1, wherein, The refrigerant pump is configured to shut down when all the corresponding compressors have stopped.

9. The air conditioning system according to claim 1, wherein, The refrigerant pump is configured to shut down when the temperature of the inverters of all the corresponding compressors is less than or equal to a second temperature threshold and the duration is greater than or equal to a fifth time threshold, and the operating time of the refrigerant pump meets a preset minimum operating time.

10. The air conditioning system according to claim 1, wherein, The refrigerant pump is configured to shut down if the refrigerant pump's operating time is greater than or equal to a preset maximum operating time.

11. The air conditioning system according to claim 1, wherein, The air conditioning system is equipped with a first pressure sensor for detecting the pressure after the refrigerant pump and a second pressure sensor for detecting the pressure of the condenser cylinder. The air conditioning system is configured to determine that the refrigerant pump is faulty if the difference between the detection value of the first pressure sensor and the detection value of the second pressure sensor is less than or equal to a first pressure threshold and the duration is greater than or equal to a sixth time threshold.

12. The air conditioning system according to claim 11, wherein, The conditions for the air conditioning system to determine that the refrigerant pump is faulty also include that the duration of the refrigerant pump being in the on state is greater than or equal to the seventh time threshold, and that the detection value of the second pressure sensor is less than or equal to the second pressure threshold and the duration is greater than or equal to the eighth time threshold.

13. The air conditioning system according to claim 11, wherein, The air conditioning system also includes a return branch, the inlet of which is connected to the rear end of the refrigerant pump and the connection position is located before all the post-pump branches. The outlet of the return branch is connected to the condenser. The return branch is equipped with a pressure regulating valve to allow part of the refrigerant to flow back to the condenser when the post-pump pressure of the refrigerant pump exceeds the set value of the pressure regulating valve.

14. The air conditioning system according to claim 13, wherein, The air conditioning system is configured to determine that the pressure regulating valve is faulty if the difference between the detection value of the first pressure sensor and the detection value of the second pressure sensor is greater than or equal to a third pressure threshold and the refrigerant pump is in the on state for a duration greater than or equal to a ninth time threshold.

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