Air conditioning system, control method of air conditioning system and air conditioner

Abstract

The invention discloses an air conditioning system, a control method of the air conditioning system and an air conditioner, and belongs to the technical field of air conditioners. The air conditioning system comprises an evaporator and a condenser, wherein the output end of the condenser is connected with the input end of the evaporator; the input ends of the compression modules are connected with the output end of the evaporator, and the output ends of the compression modules are connected with the input end of the condenser; the compression module comprises a compressor, a one-way valve and a switch valve with the adjustable opening degree, the one-way valve is arranged between the compressor and the condenser, the conduction direction of the one-way valve points to the condenser, and the switch valve is connected with the compressor in parallel; the controller is connected with the at least two compression modules and used for determining the target opening degree of the switching valve connected with a second compressor in parallel based on the running state parameters of the first compressor and adjusting the opening degree of the switching valve connected with the second compressor in parallel to the target opening degree, the first compressor is the compressor in the starting state, and the second compressor is the compressor in the starting state. The second compressor is a compressor to be started.

Description

Technical Field

[0001] This application belongs to the technical field of air conditioners, and particularly relates to an air conditioning system, a control method for the air conditioning system, and an air conditioner. Background Art

[0002] An air conditioning system may include multiple compressors. When the currently operating compressors are fully loaded and still cannot meet the load demand, compressors that have not been started yet can be started to increase the refrigeration capacity of the system. If the compression ratio of the compressor unit is relatively high, the exhaust back pressure of the subsequently started compressors will be relatively large, making it difficult to start the compressors. Therefore, a cut-off valve is usually provided between the exhaust pipe and the intake end of the compressor. Before starting the compressor, the cut-off valve is opened to release some high-pressure gas.

[0003] Currently, usually before the cut-in compressor starts, the cut-off valve is controlled to be fully opened and then closed after the compressor starts. However, when the cut-off valve is fully opened, most of the high-pressure gas may flow out through the pipeline where the cut-off valve is located during high-pressure ratio start-up, resulting in the exhaust check valve not being able to be opened due to gas flow distribution problems after the compressor starts. When the cut-off valve is closed, affected by the exhaust back pressure, the compressor cannot be smoothly cut in, causing a failure of the compressor unit. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems existing in the prior art. For this purpose, this application provides an air conditioning system, a control method for the air conditioning system, and an air conditioner, which can adjust the exhaust back pressure of the second compressor, enable the second compressor to be normally cut in and work, and improve the safety and reliability of the air conditioning system.

[0005] In a first aspect, this application provides an air conditioning system, including:

[0006] An evaporator and a condenser, the output end of the condenser is connected to the input end of the evaporator;

[0007] At least two compression modules, the input end of the compression module is connected to the output end of the evaporator, and the output end of the compression module is connected to the input end of the condenser;

[0008] The compression module includes a compressor, a one-way valve, and a switch valve with adjustable opening degree. The one-way valve is arranged between the compressor and the condenser, the conduction direction of the one-way valve points to the condenser, and the switch valve is connected in parallel with the compressor;

[0009] A controller, connected to at least two of the compression modules, is configured to determine a target opening degree of the switching valve in parallel with the second compressor based on the operating state parameters of the first compressor, and adjust the opening degree of the switching valve in parallel with the second compressor to the target opening degree. The first compressor is the compressor in the on state, and the second compressor is the compressor to be started.

[0010] According to the air-conditioning system of the present application, by determining the target opening degree of the switching valve in parallel with the second compressor based on the operating state parameters of the first compressor and adjusting the opening degree of the switching valve to the target opening degree, the opening degree of the switching valve can reach a state where the exhaust back pressure can be relieved and the gas discharged from the second compressor flows out of the pipeline where the switching valve is located as little as possible, so that the second compressor can be started smoothly, and the pressure at the output end after starting is large enough to push open the connected check valve, thereby adjusting the exhaust back pressure of the second compressor, enabling the second compressor to work normally, and improving the safety and reliability of the air-conditioning system.

[0011] According to an embodiment of the present application, the controller is configured to determine a target flow capacity of the switching valve in parallel with the second compressor based on the operating state parameters, and determine the target opening degree based on the target flow capacity.

[0012] According to an embodiment of the present application, the controller is configured to determine a target ventilation flow of the switching valve in parallel with the second compressor based on the exhaust flow parameter in the operating state parameters, and the target flow capacity is determined based on the target ventilation flow.

[0013] According to an embodiment of the present application, the controller is configured to determine the product of the exhaust flow parameter and a preset coefficient as the target valve flow.

[0014] According to an embodiment of the present application, the controller is configured to control the second compressor to start when the opening degree of the switching valve in parallel with the second compressor is the target opening degree, and control the switching valve in parallel with the second compressor to close when the second compressor has completed starting.

[0015] According to an embodiment of the present application, the compressor is a magnetic levitation centrifugal compressor.

[0016] According to an embodiment of the present application, the air-conditioning system further includes:

[0017] A sensor module, provided in at least two of the compression modules, for detecting physical parameters of the refrigerant flowing through the first compressor and generating corresponding sensing data;

[0018] The controller is connected to the sensor module.

[0019] According to an embodiment of the present application, the air conditioning system further includes:

[0020] A throttle valve, the input end of the throttle valve is connected to the output end of the condenser, and the output end of the throttle valve is connected to the input end of the evaporator.

[0021] In a second aspect, the present application provides a control method for an air conditioning system, the method includes:

[0022] Based on the operating state parameters of the first compressor, determine the target opening degree of the switching valve connected in parallel with the second compressor;

[0023] Adjust the opening degree of the switching valve connected in parallel with the second compressor to the target opening degree, where the first compressor is the compressor in the on state, and the second compressor is the compressor to be started.

[0024] According to the control method of the air conditioning system of the present application, by using the operating state parameters of the first compressor to determine the target opening degree of the switching valve connected in parallel with the second compressor and adjusting the opening degree of the switching valve to the target opening degree, the opening degree of the switching valve can reach a state where the exhaust back pressure can be relieved and the gas discharged from the second compressor flows out of the pipeline where the switching valve is located as little as possible, so that the second compressor can be started smoothly, and the pressure at the output end after starting is large enough to push open the connected one-way valve, thereby adjusting the exhaust back pressure of the second compressor, enabling the second compressor to work normally, and improving the safety and reliability of the air conditioning system.

[0025] According to an embodiment of the present application, the method further includes:

[0026] When the opening degree of the switching valve connected in parallel with the second compressor is the target opening degree, control the second compressor to start;

[0027] When the second compressor starts successfully, control the switching valve connected in parallel with the second compressor to close.

[0028] In a third aspect, the present application provides an air conditioner, including:

[0029] The air conditioning system as described in the first aspect above.

[0030] For the air conditioner according to the present application, by determining the target opening degree of the switching valve in parallel with the second compressor based on the operating state parameters of the first compressor and adjusting the opening degree of the switching valve to the target opening degree, the opening degree of the switching valve can reach a state where the exhaust back pressure can be alleviated and the gas discharged from the second compressor flows out of the pipeline where the switching valve is located as little as possible, so that the second compressor can be smoothly started, and the pressure at the output end after starting is large enough to push open the connected check valve, thereby adjusting the exhaust back pressure of the second compressor, enabling the second compressor to work normally, and improving the safety and reliability of the air conditioning system.

[0031] In a fourth aspect, the present application provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the control method of the air conditioning system as described in the first aspect above.

[0032] In a fifth aspect, the present application provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the control method of the air conditioning system as described in the first aspect above.

[0033] In a sixth aspect, the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the control method of the air conditioning system as described in the first aspect above.

[0034] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0036] Figure 1 is a schematic structural diagram of the air conditioning system provided by the embodiment of the present application;

[0037] Figure 2 is a schematic structural diagram of the air conditioning system in the related art;

[0038] Figure 3 is a schematic diagram of the enthalpy value of the refrigerant in the air conditioning system provided by the embodiment of the present application;

[0039] Figure 4 is a schematic diagram of the relationship between the flow capacity and the opening degree of the switching valve provided by the embodiment of the present application;

[0040] Figure 5 is one of the flow schematic diagrams of the control method of the air conditioning system provided by the embodiment of the present application;

[0041] Figure 6 It is the second schematic flow chart of the control method of the air conditioning system provided by the embodiment of the present application;

[0042] Figure 7 It is the schematic structural diagram of the electronic device provided by the embodiment of the present application.

[0043] Reference numerals:

[0044] Air conditioning system 100, evaporator 111, condenser 112, compressor 113, check valve 114, switching valve 115,

[0045] Controller 116, throttle valve 117. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0047] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. generally belong to the same category, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally represents an "or" relationship between the associated objects before and after.

[0048] Next, the air conditioning system 100, the control method of the air conditioning system 100, and the air conditioner provided by the embodiments of the present application will be described in detail with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0049] As Figure 1 shown, the air conditioning system 100 includes an evaporator 111, a condenser 112, at least two compression modules, and a controller 116.

[0050] The output end of the condenser 112 is connected to the input end of the evaporator 111, the input end of the compression module is connected to the output end of the evaporator 111, the output end of the compression module is connected to the input end of the condenser 112, and the controller 116 is connected to at least two compression modules.

[0051] Among them, the evaporator 111 is a device that can evaporate low-temperature and low-pressure liquid refrigerant into gas, absorb heat from the ambient air to lower the ambient temperature, and the condenser 112 is a device that can condense high-temperature and high-pressure gaseous refrigerant into liquid to release heat.

[0052] In this embodiment, the compression module includes a compressor 113, a check valve 114, and a switch valve 115 with adjustable opening degree. The check valve 114 is arranged between the compressor 113 and the condenser 112, and the conduction direction of the check valve 114 points to the condenser 112. The switch valve 115 is connected in parallel with the compressor 113.

[0053] Among them, the compressor 113 is a device that compresses low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure gas to provide power for the refrigeration cycle.

[0054] The check valve 114 is a valve structure that controls the flow of refrigerant gas in the direction from the compressor 113 to the condenser 112 and prohibits reverse flow. When the compressor 113 is running, the high-pressure gas discharged by the compressor 113 can push the valve core of the check valve 114 to open, allowing the refrigerant to flow to the condenser 112.

[0055] The switch valve 115 is a valve structure with adjustable opening degree. When the switch valve 115 is opened, the refrigerant gas discharged from the compressor 113 can flow into the passage where the switch valve 115 is located.

[0056] In this embodiment, the compressor 113 starts, the compressor 113 sucks in low-temperature and low-pressure gaseous refrigerant, compresses it into high-temperature and high-pressure gas to provide power for the refrigeration cycle. The high-temperature and high-pressure gaseous refrigerant enters the condenser 112, and the condenser 112 gradually releases heat to condense the refrigerant into liquid. After the refrigerant undergoes throttling and pressure reduction, the low-temperature and low-pressure refrigerant enters the evaporator 111, and the refrigerant is completely evaporated into low-temperature and low-pressure gas in the evaporator 111, and then returns to the compressor 113 to start a new cycle.

[0057] When the load demand of the air-conditioning system 100 still cannot be met under the full-load state of the compressor 113 in the on state, the compressor 113 that has not been started in the air-conditioning system 100 can be started to meet the load demand.

[0058] In this embodiment, the controller 116 is used to determine the target opening degree of the switch valve 115 connected to the second compressor and in parallel with the second compressor based on the operating state parameters of the first compressor, and adjust the opening degree of the switch valve 115 connected to the second compressor to the target opening degree.

[0059] Among them, the first compressor is the compressor 113 in the startup state, and the second compressor is the compressor 113 to be started. The air-conditioning system 100 may include one or more first compressors, and may also include one or more compressors 113 that have not been started yet. One or more second compressors may be determined from the compressors 113 that have not been started yet.

[0060] It should be noted that the models of the multiple compressors 113 in the air-conditioning system 100 may be the same. According to the operating state parameters of any first compressor, the target opening degree of the switching valve 115 in parallel with the second compressor can be determined. The second compressor may be any compressor 113 that has not been started yet.

[0061] In this embodiment, the operating state parameters are physical quantities that can characterize the performance and conditions during the operation of the first compressor, and may include the operating power of the first compressor, the generated gas pressure, the generated gas flow rate, as well as the temperature and enthalpy value of the refrigerant at the inlet and outlet.

[0062] In this embodiment, the controller 116 obtains the operating state parameters of the first compressor in real time. According to the operating state parameters, through a preset algorithm or formula, etc., the controller 116 calculates in real time the target opening degree of the switching valve 115 in parallel with the second compressor. The target opening degree is the opening degree that the switching valve 115 in parallel with the second compressor is expected to reach. When the switching valve 115 in parallel with the second compressor is at the target opening degree, the back pressure of the second compressor can be reduced, and the gas discharged from the second compressor can be minimized from flowing out of the pipeline where the switching valve 115 in parallel with the second compressor is located.

[0063] For example, the operating state parameters may include the exhaust pressure of the first compressor, and the target opening degree may be positively correlated with the exhaust pressure of the first compressor. That is, when the exhaust pressure of the first compressor is greater, the controller 116 determines a larger target opening degree and adjusts the opening degree of the switching valve 115 in parallel with the second compressor to the target opening degree to reduce the back pressure of the second compressor.

[0064] In this embodiment, the controller 116 can drive a drive mechanism such as a motor connected to the switching valve 115 in parallel with the second compressor to adjust the opening degree by sending an instruction to the switching valve 115 in parallel with the second compressor.

[0065] In the related art, usually before the cut-in compressor starts, the cut-off valve is controlled to be fully opened and then closed after the compressor starts. However, when the cut-off valve is fully opened, most of the high-pressure gas may flow out through the pipeline where the cut-off valve is located during high-pressure ratio startup, resulting in that the corresponding exhaust check valve cannot be opened due to gas flow distribution problems after the compressor starts. When the cut-off valve is closed, affected by the exhaust back pressure, the compressor cannot be smoothly cut in, causing the compression unit to malfunction.

[0066] In the embodiment of the present application, based on the operating state parameters of the first compressor, the target opening degree of the switching valve 115 in parallel with the second compressor is determined, and the opening degree of the switching valve 115 in parallel with the second compressor is adjusted to the target opening degree. The operating state parameters of the first compressor can reflect the exhaust back pressure of the second compressor. Adjusting the opening degree of the switching valve 115 in parallel with the second compressor according to the operating state parameters of the first compressor can make the opening degree of the switching valve 115 in parallel with the second compressor reach a state where the exhaust back pressure can be relieved and the gas discharged by the second compressor flows out of the pipeline where the switching valve 115 is located as little as possible, so that the second compressor can be smoothly started, and the pressure at the output end after starting is large enough to push open the connected check valve 114, thereby adjusting the exhaust back pressure of the second compressor, enabling the second compressor to work normally, and improving the safety and reliability of the air-conditioning system 100.

[0067] In the related art, as Figure 2 shown, to reduce the risk of failure when starting a compressor in a multi-compressor system, usually one compressor is designed for a set of independent fluorine systems. The fluorine systems are independent, and the container water pipelines are in series. When the currently started compressor does not meet the load, other compressors are started. When the pressure in the independent system where the compressor to be started is located is in a balanced state and there is no back pressure on the check valve, the compressor is easier to start. However, since the fluorine systems are independent, taking two compressors as an example, when only one compressor is running, the heat exchanger corresponding to the other compressor cannot participate in heat exchange, and the heat exchange area is reduced by half compared to the common refrigerant system, and the container heat exchange area cannot be fully utilized, which is not conducive to the efficient operation of the compressor.

[0068] In the embodiment of the present application, the air-conditioning system 100 includes at least two compression modules, and all compression modules are connected to the same heat exchange system including an evaporator 111 and a condenser 112, which can fully utilize the heat exchange area and improve the operating efficiency of the compressor 113.

[0069] According to the air-conditioning system 100 provided by the embodiment of the present application, by determining the target opening degree of the switching valve 115 in parallel with the second compressor based on the operating state parameters of the first compressor and adjusting the opening degree of the switching valve 115 to the target opening degree, the opening degree of the switching valve 115 can reach a state where the exhaust back pressure can be relieved and the gas discharged by the second compressor flows out of the pipeline where the switching valve 115 is located as little as possible, so that the second compressor can be smoothly started, and the pressure at the output end after starting is large enough to push open the connected check valve 114, thereby adjusting the exhaust back pressure of the second compressor, enabling the second compressor to work normally, and improving the safety and reliability of the air-conditioning system 100.

[0070] In some embodiments, the controller 116 is configured to determine the target flow capacity of the switching valve 115 in parallel with the second compressor based on the operating state parameters, and determine the target opening degree based on the target flow capacity.

[0071] The target flow capacity is the capacity of the switching valve 115 in parallel with the second compressor to allow fluid to pass through at the target opening degree, which can be expressed as the maximum fluid volume flowing through per unit time.

[0072] In this embodiment, the controller 116 can determine the exhaust back pressure of the second compressor, etc. according to the operating state parameters, and determine the volume of gas expected to flow out through the pipeline where the switching valve 115 in parallel with the second compressor is located, etc. According to the relevant physical parameters of the flowing refrigerant gas, the target flow capacity is determined.

[0073] In this embodiment, based on the target flow capacity, the target opening degree can be calculated through the fitting formula between the flow capacity and the opening degree corresponding to the switching valve 115.

[0074] In some embodiments, the controller 116 is configured to determine the target ventilation flow rate of the switching valve 115 in parallel with the second compressor based on the exhaust flow rate parameter in the operating state parameters, and the target flow capacity is determined based on the target ventilation flow rate.

[0075] Among them, the operating state parameters include the exhaust flow rate parameter, the exhaust flow rate parameter is the volume of gas discharged by the first compressor per unit time, and the target ventilation flow rate is the volume of gas expected to flow through the switching valve 115 in parallel with the second compressor per unit time.

[0076] In this embodiment, the target ventilation flow rate can be determined according to the exhaust flow rate parameter, taking into account the specifications and models of the second compressor, etc.

[0077] In this embodiment, the target flow capacity can be determined according to the target ventilation flow rate through the calculation formula between the flow capacity and the ventilation flow rate corresponding to the switching valve 115.

[0078] In some embodiments, the controller 116 is configured to determine the product of the exhaust flow rate parameter and a preset coefficient as the target ventilation flow rate.

[0079] Among them, the preset coefficient is a preset constant, the preset coefficient can be set based on the model specifications of the second compressor, etc., and the value range of the preset coefficient can be 0.1 - 1.0.

[0080] Next, take Figure 1Taking the air conditioning system 100 shown as an example, a specific embodiment of a controller 116 determining a target opening based on operating state parameters is introduced. Among them, the compressor 113 labeled as 1# is used as the first compressor, and the compressor 113 labeled as 2# is used as the second compressor.

[0081] Corresponding calculation formulas can be configured in the controller 116, enabling the controller 116 to determine the target opening based on the operating state parameters.

[0082] The input power of the first compressor is

[0083] P 1# = m1×(h2 - h1)

[0084] The mass flow rate of the refrigerant flowing through the first compressor can be derived as

[0085] m1 = (P 1# ) / ((h2 - h1))

[0086] Wherein, P 1# is the input power of the first compressor, with the unit of kW, which can be directly read through the power meter carried by the first compressor. h1 is Figure 1 the enthalpy value of the refrigerant at the input end of the first compressor, with the unit of kJ / kg. h2 is Figure 1 the enthalpy value of the refrigerant at the output end of the first compressor, with the unit of kJ / kg. m1 is the mass flow rate of the refrigerant flowing through the first compressor, with the unit of kg / h.

[0087] The exhaust flow rate parameter of the first compressor is

[0088] V 1# = m1÷ρ ②

[0089] Wherein, V 1# is the exhaust flow rate parameter of the first compressor, with the unit of m 3 / h. ρ ② is the exhaust fluid density of the first compressor, with the unit of kg / m 3 .

[0090] Table 1

[0091]

[0092] In this embodiment, as Figure 3 shown, Figure 1The enthalpy values of the refrigerant at positions ①-⑥, where position ① is the suction port of the first compressor, position ② is the discharge port of the first compressor, position ③ is the liquid outlet of the condenser 112, position ④ is the outlet of the throttle valve 117, position ⑤ is the suction port of the second compressor, and position ⑥ is the discharge port of the second compressor.

[0093] The enthalpy value can be calculated by a polynomial fitting equation. The enthalpy value of the refrigerant is a function of its state temperature and pressure. The enthalpy value can also be obtained using software such as NIST REFPROP. The enthalpy calculation method can be implanted into the controller 116. After collecting the pressure and temperature of the refrigerant at each position, the enthalpy value at each position is calculated by the controller 116.

[0094] After the second compressor is turned on, refer to Table 1 for the method of confirming the refrigerant state and enthalpy value at each of positions ①-⑥.

[0095] The enthalpy value h1 at the suction port of the first compressor = Enthalpy("refrigerant type","TP","SI",Ts1,Ps1).

[0096] The exhaust fluid density ρ at the discharge port of the first compressor ② = Density("refrigerant type","Ph","SI",h1,Pd1).

[0097] Among them, Ps1 and Ts1 respectively represent the pressure (gage pressure, MPa) and temperature (Kelvin temperature, t + 273.15) at state point ①, Pd1 represents the pressure (gage pressure, MPa) at state point ②. The refrigerant type is filled in according to the actual type selected for the air conditioner, such as R134a, R410a, R1234ze, etc. TP, Ph, and SI are fixed parameters of the Enthalpy method and Density method in NIST REFPROP.

[0098] In this embodiment, the relevant calculation program is implanted into the controller 116, and the first compressor performs real-time calculation m1 to calculate the exhaust flow parameter V of the first compressor. 1# .

[0099] In this embodiment, before switching to the second compressor, the opening degree of the switching valve 115 in parallel with the second compressor is assigned. The opening degree of the switching valve 115 is assigned according to the required machine-switching flow calculated based on the operating state of the compressor 113 group. The value of the machine-switching flow is calculated based on the parameter value of the first compressor.

[0100] In this embodiment, the relationship between the flow capacity Cv and the opening degree of the switching valve 115 in parallel with the second compressor is as Figure 4 shown, and the corresponding fitting formula is

[0101] Cv = ax^3 + bx^2 + cx + d

[0102] Wherein, a, b, c, and d are constants, x is the opening degree of the valve, and the unit is %.

[0103] In the national standard, Cv and Kv of the valve are a parameter and a representation method for indicating the gas flow characteristics, and the relationship between the Kv value and the Cv value is Cv = 1.156Kv.

[0104] Measurement of the Kv value: When the measured element is fully open, the pressure difference ΔP0 across the element is 0.1 MPa, and the fluid density ρ = 1 g / cm 3 When, the flow rate through the element is V (m 3 / h), then the flow capacity Kv value is:[[]]END]]

[0105] Kv = V * [ρ * ΔP0 / (ρ0 * ΔP)]^0.5

[0106] Wherein, V represents the target ventilation flow rate, and the unit is m 3 / h, ρ represents the actual density of the fluid, and the unit is kg / m 3 , ΔP0 represents the standard pressure difference, that is, 0.1 MPa, ρ0 represents the standard fluid density, that is, 1000 kg / m 3 , and ΔP represents the actually measured pressure difference.

[0107] The bypass flow required to cut into the second compressor under different working conditions, that is, the target ventilation flow rate is

[0108] V = K × V 1#

[0109] Wherein, K is the coefficient of the required cutting machine flow rate, that is, a preset coefficient, and is a fixed value between 0.1 and 1.0.

[0110] After calculating the Kv value, Cv = 1.156Kv, and the target opening degree x required during cutting can be calculated according to the fitting formula.

[0111] In this embodiment, when the first compressor is running, the pressure of the condenser 112 cylinder is on the high side, and the pressure after the check valve, that is, the one-way valve 114 connected to the second compressor is high. If the second compressor does not bypass the flow through the connected switching valve 115 when starting, in the initial stage, affected by the back pressure, the second compressor cannot open the connected one-way valve 114 when starting, and the exhaust gas cannot be discharged.

[0112] In some embodiments, the controller 116 is configured to control the opening of the second compressor when the opening degree of the switching valve 115 connected in parallel with the second compressor is the target opening degree, and to control the closing of the switching valve 115 connected in parallel with the second compressor when the second compressor has completed starting.

[0113] In this embodiment, when the opening degree of the switching valve 115 in parallel with the second compressor reaches the target opening degree, the second compressor is controlled to start. During the start-up process, the gas discharged by the second compressor can flow out through the pipeline where the parallel switching valve 115 is located, relieving the back pressure. After the second compressor is started, the switching valve 115 in parallel with the second compressor is controlled to close, and the gas discharged by the second compressor does not flow through the pipeline where the switching valve 115 is located, pushing the connected check valve 114 to open, realizing the cut-in to the air-conditioning system 100.

[0114] In some embodiments, the compressor 113 is a magnetic levitation centrifugal compressor.

[0115] Among them, the magnetic levitation centrifugal compressor is a centrifugal compressor that uses magnetic levitation technology to achieve rotor suspension.

[0116] The magnetic levitation centrifugal compressor has an inherent characteristic of surging, and is prone to surging alarms under conditions such as too high or too low pressure ratio, and air flow disturbance.

[0117] Magnetic levitation centrifugal chillers are recognized by more and more users due to their high-efficiency advantages. However, at present, the single-unit cooling capacity of magnetic levitation compressors is relatively small compared with that of conventional centrifugal compressors. When there is a large cooling capacity demand, multiple compressors are required to cope. In a multi-compressor common refrigerant system, when the currently operating compressor is fully loaded and still does not meet the user's load demand, it is necessary to start the unstarted compressor to increase the system cooling capacity. If the unit pressure ratio is on the high side, the exhaust back pressure of the subsequently started compressor is greater, and it is more difficult to add a compressor head. It is necessary to add a cut-in valve, that is, a switching valve, to assist in adding a compressor head.

[0118] In the related art, the valve is mostly fully opened before the compressor to be cut in starts, and closed after the compressor starts. However, for a magnetic levitation centrifugal compressor, at the same speed, the volume flow rate is different with different pressure ratios. The higher the pressure ratio, the smaller the volume flow rate. When the valve is fully opened during high-pressure ratio start-up, the volume flow rate may mostly flow out through the cut-in pipeline. Although the compressor has started, the exhaust check valve cannot be opened due to the flow distribution problem. When the cut-in valve is closed, affected by the exhaust back pressure, the magnetic levitation rotating shaft shakes, resulting in an alarm for the unit.

[0119] In the embodiment of the present application, by using the operating state parameters of the first compressor, the target opening degree of the switching valve 115 in parallel with the second compressor is determined, and the opening degree of the switching valve 115 is adjusted to the target opening degree, so that the opening degree of the switching valve 115 can reach a state where the exhaust back pressure can be relieved and the gas discharged by the second compressor flows out of the pipeline where the switching valve 115 is located as little as possible, so that the second compressor can be started smoothly, and the pressure at the output end after start-up is large enough to push open the connected check valve 114, thereby adjusting the exhaust back pressure of the second compressor, enabling the second compressor to work normally, and improving the safety and reliability of the air-conditioning system 100.

[0120] In some embodiments, the air conditioning system 100 further includes a sensor module.

[0121] The sensor module is disposed in at least two compression modules, and is configured to detect physical parameters of the refrigerant flowing through the first compressor and generate corresponding sensing data.

[0122] The controller 116 is connected to the sensor module.

[0123] In this embodiment, the controller 116 is configured to determine the operating state parameters based on the sensing data.

[0124] Among them, the physical parameters may include temperature, pressure, etc. The sensor module may include a temperature sensor, a pressure sensor, etc., and may detect the temperature and pressure of the refrigerant in the circulation path. The temperature sensor and the pressure sensor may be disposed at the input end and the output end of the compressor 113.

[0125] Such as Figure 1 shown, Ps1 is the pressure sensor disposed at the input end of the compressor 113 numbered 1#, Pd1 is the pressure sensor disposed at the output end of the compressor 113 numbered 1#, Ts1 is the temperature sensor disposed at the input end of the compressor 113 numbered 1#, and Td1 is the temperature sensor disposed at the output end of the compressor 113 numbered 1#.

[0126] Ps2 is the pressure sensor disposed at the input end of the compressor 113 numbered 2#, Pd2 is the pressure sensor disposed at the output end of the compressor 113 numbered 2#, Ts2 is the temperature sensor disposed at the input end of the compressor 113 numbered 1# (should be Ts2 is the temperature sensor disposed at the input end of the compressor 113 numbered 2#), and Td2 is the temperature sensor disposed at the output end of the compressor 113 numbered 2#.

[0127] In this embodiment, when a certain compressor 113 is operating, i.e., the first compressor, the sensors connected to the first compressor detect the corresponding parameters, transmit the generated sensing data to the controller 116, and the controller 116 calculates the corresponding enthalpy value according to the pressure sensing data and the temperature sensing data, and determines the operating state parameters according to the obtained enthalpy value.

[0128] In some embodiments, as Figure 1 shown, the air conditioning system 100 further includes:

[0129] A throttle valve 117, the input end of the throttle valve 117 is connected to the output end of the condenser 112, and the output end of the throttle valve 117 is connected to the input end of the evaporator 111.

[0130] Among them, the throttle valve 117 is a device that can control the flow rate of the refrigerant in the system, thereby regulating the pressure and temperature of the refrigerant. The throttle valve 117 can be a capillary tube, an expansion valve, etc.

[0131] The embodiment of the present application also provides a control method for an air conditioning system 100.

[0132] Among them, the control method of the air conditioning system 100 can be applied to a terminal, and specifically can be executed by hardware or software in the terminal.

[0133] The terminal includes, but is not limited to, portable communication devices such as mobile phones or tablet computers having a touch-sensitive surface (for example, a touch screen display and / or a touchpad). It should also be understood that in some embodiments, the terminal may not be a portable communication device, but a desktop computer having a touch-sensitive surface (for example, a touch screen display and / or a touchpad).

[0134] In the following various embodiments, a terminal including a display and a touch-sensitive surface is described. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, a mouse, and a joystick.

[0135] The control method of the air conditioning system 100 provided by the embodiment of the present application. The execution subject of the control method of the air conditioning system 100 can be an electronic device or a functional module or functional entity in the electronic device that can implement the control method of the air conditioning system 100. The electronic devices mentioned in the embodiment of the present application include, but are not limited to, mobile phones, tablet computers, computers, cameras, and wearable devices, etc. Hereinafter, taking the electronic device as the execution subject as an example, the control method of the air conditioning system 100 provided by the embodiment of the present application is described.

[0136] As Figure 5 shown, the control method of the air conditioning system 100 includes: step 510 and step 520.

[0137] Step 510: Based on the operating state parameters of the first compressor, determine the target opening degree of the switching valve 115 in parallel with the second compressor.

[0138] Step 520: Adjust the opening degree of the switching valve 115 in parallel with the second compressor to the target opening degree. The first compressor is the compressor 113 in the on state, and the second compressor is the compressor 113 to be started.

[0139] According to the control method of the air conditioning system 100 provided by the embodiments of the present application, by using the operating state parameters of the first compressor, the target opening degree of the switching valve 115 in parallel with the second compressor is determined, and the opening degree of the switching valve 115 is adjusted to the target opening degree, so that the opening degree of the switching valve 115 can reach a state where the exhaust back pressure can be relieved and the gas discharged from the second compressor flows out of the pipeline where the switching valve 115 in parallel with the second compressor is located as little as possible, so that the second compressor can be smoothly started, and the pressure at the output end after starting is large enough to push open the connected check valve 114, thereby adjusting the exhaust back pressure of the second compressor, so that the second compressor can work normally, and the safety and reliability of the air conditioning system 100 can be improved.

[0140] In some embodiments, the control method of the air conditioning system 100 further includes:

[0141] When the opening degree of the switching valve 115 in parallel with the second compressor is the target opening degree, control the second compressor to start;

[0142] When the second compressor starts successfully, control the switching valve 115 in parallel with the second compressor to close.

[0143] The following introduces a specific embodiment of the control method of the air conditioning system 100.

[0144] As Figure 1 shown, the compressor 113 numbered 1# is used as the first compressor, and the compressor 113 numbered 2# is used as the second compressor.

[0145] As Figure 6 shown, when the first compressor runs, when the condition for adding a compressor head is met, that is, when the first compressor runs and does not meet the load, the controller 116 records the pressure and temperature of the refrigerant at the input end and the output end of the first compressor and the input power of the first compressor, and calculates the exhaust gas flow parameter V 1# of the first compressor according to the recorded data. According to the exhaust gas flow parameter V 1# , calculate the cut-in flow rate that needs to be bypassed when the second compressor cuts in, that is, the target ventilation flow rate V of the switching valve 115 in parallel with the second compressor. Calculate the target opening degree of the switching valve 115 in parallel with the second compressor according to the target ventilation flow rate V, adjust the switching valve 115 in parallel with the second compressor to the target opening degree, control the second compressor to start, and after the start is completed, the controller 116 closes the switching valve 115 in parallel with the second compressor, and the two compressors 113 enter the load adjustment synchronously.

[0146] In the related art, when the compressor is turned on under any working condition, the connected cut-in valve remains fully open. In some working conditions, a relatively large amount of cut-off flow passes through the bypass of the cut-in valve. After the compressor starts up, the check valve is not opened, resulting in the pressure in the condenser cylinder being greater than the pressure at the output end of the compressor. When the cut-in valve is closed after the compressor starts up, even if a cut-off valve is set in the system to assist in starting, the compressor cannot be smoothly cut in due to the influence of back pressure, resulting in a unit failure.

[0147] In the embodiment of the present application, based on the operating state parameters of the first compressor, the target opening degree of the switching valve 115 connected to the second compressor and in parallel with the second compressor is determined, and the opening degree of the switching valve 115 is adjusted to the target opening degree, so that the opening degree of the switching valve 115 can reach a state where the exhaust back pressure can be relieved and the gas discharged from the second compressor flows out of the pipeline where the switching valve 115 is located as little as possible, so that the second compressor can be smoothly started, and the pressure at the output end after starting is large enough to push open the connected check valve 114, thereby adjusting the exhaust back pressure of the second compressor, so that the second compressor can work normally, and the safety and reliability of the air conditioning system 100 can be improved.

[0148] The embodiment of the present application also provides an air conditioner.

[0149] The air conditioner includes the air conditioning system 100 as described above.

[0150] According to the air conditioner provided by the embodiment of the present application, based on the operating state parameters of the first compressor, the target opening degree of the switching valve 115 in parallel with the second compressor is determined, and the opening degree of the switching valve 115 is adjusted to the target opening degree, so that the opening degree of the switching valve 115 can reach a state where the exhaust back pressure can be relieved and the gas discharged from the second compressor flows out of the pipeline where the switching valve 115 is located as little as possible, so that the second compressor can be smoothly started, and the pressure at the output end after starting is large enough to push open the connected check valve 114, thereby adjusting the exhaust back pressure of the second compressor, so that the second compressor can work normally, and the safety and reliability of the air conditioning system 100 can be improved.

[0151] In some embodiments, as Figure 7 shown, the embodiment of the present application also provides an electronic device 700, including a processor 701, a memory 702, and a computer program stored on the memory 702 and executable on the processor 701. When the program is executed by the processor 701, it implements each process of the control method embodiment of the above air conditioning system 100 and can achieve the same technical effect. To avoid repetition, it will not be described here again.

[0152] It should be noted that the electronic device in the embodiment of the present application includes the above-mentioned mobile electronic device and non-mobile electronic device.

[0153] An embodiment of the present application further provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements each process of the control method embodiment of the above-mentioned air-conditioning system 100 and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0154] Among them, the processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes computer-readable storage media, such as computer read-only memory ROM, random access memory RAM, magnetic disks, or optical discs, etc.

[0155] An embodiment of the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the control method of the above-mentioned air-conditioning system 100.

[0156] Among them, the processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes computer-readable storage media, such as computer read-only memory ROM, random access memory RAM, magnetic disks, or optical discs, etc.

[0157] Another embodiment of the present application provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement each process of the control method embodiment of the above-mentioned air-conditioning system 100 and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0158] It should be understood that the chip mentioned in the embodiment of the present application may also be referred to as a system-on-chip, system chip, chip system, or system-on-chip, etc.

[0159] It should be noted that in this article, the term "including", "comprising", or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article, or device. Without more limitations, the element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article, or device including the element. In addition, it should be pointed out that the methods and devices in the embodiments of the present application are not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0160] Through the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases, the former is a better implementation method. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present application.

[0161] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection scope of the present application.

[0162] In the description of this specification, the description of reference terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do 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.

[0163] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. An air conditioning system, characterized in that, Comprising: An evaporator and a condenser, the output end of the condenser being connected to the input end of the evaporator; At least two compression modules, the input end of the compression module being connected to the output end of the evaporator, and the output end of the compression module being connected to the input end of the condenser; The compression module includes a compressor, a check valve, and a switch valve with adjustable opening degree. The check valve is arranged between the compressor and the condenser, and the conduction direction of the check valve points to the condenser. The switch valve is connected in parallel with the compressor; A controller, connected to at least two of the compression modules, for determining the target opening degree of the switch valve connected in parallel with the second compressor based on the operating state parameters of the first compressor, and adjusting the opening degree of the switch valve connected in parallel with the second compressor to the target opening degree. The first compressor is the compressor in the on state, and the second compressor is the compressor to be started.

2. The air conditioning system according to claim 1, wherein The controller is used to determine the target flow capacity of the switch valve connected in parallel with the second compressor based on the operating state parameters, and determine the target opening degree based on the target flow capacity.

3. The air-conditioning system according to claim 2, characterized in that, The controller is used to determine the target ventilation flow rate of the switch valve connected in parallel with the second compressor based on the exhaust flow rate parameter in the operating state parameters, and the target flow capacity is determined based on the target ventilation flow rate.

4. The air-conditioning system according to claim 3, characterized in that, The controller is used to determine the target ventilation flow rate as the product of the exhaust flow rate parameter and a preset coefficient.

5. The air-conditioning system according to any one of claims 1-4, characterized in that, The controller is used to control the second compressor to start when the opening degree of the switch valve connected in parallel with the second compressor is the target opening degree, and control the switch valve connected in parallel with the second compressor to close when the second compressor starts up.

6. The air conditioning system according to any one of claims 1-4, characterized in that, The compressor is a magnetic levitation centrifugal compressor.

7. The air-conditioning system according to any one of claims 1-4, characterized in that, Further comprising: A sensor module, arranged on at least two of the compression modules, for detecting the physical parameters of the refrigerant flowing through the first compressor and generating corresponding sensing data; The controller is connected to the sensor module.

8. The air conditioning system according to any one of claims 1 to 4, characterized in that, Further comprising: A throttle valve, the input end of the throttle valve being connected to the output end of the condenser, and the output end of the throttle valve being connected to the input end of the evaporator.

9. A control method for an air conditioning system according to any one of claims 1-8, characterized in that, Comprising: Determining the target opening degree of the switch valve connected in parallel with the second compressor based on the operating state parameters of the first compressor; Adjusting the opening degree of the switch valve connected in parallel with the second compressor to the target opening degree, where the first compressor is the compressor in the on state, and the second compressor is the compressor to be started.

10. The control method of the air conditioning system according to claim 9, characterized in that, The method further comprises: Controlling the second compressor to start when the opening degree of the switch valve connected in parallel with the second compressor is the target opening degree; Controlling the switch valve connected in parallel with the second compressor to close when the second compressor starts up.

11. An air conditioner, characterized in that, Comprising: The air conditioning system according to any one of claims 1-8.

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