Control method, device and system for constant-temperature oil return of air conditioner and industrial control cabinet air conditioner

Abstract

The invention provides an air conditioner constant-temperature oil return control method, device and system and an industrial control cabinet air conditioner, and relates to the technical field of air conditioner control. The method comprises the steps that state parameters of a compressor of a target air conditioner are obtained; wherein the state parameters comprise thermodynamic parameters and frequency conversion parameters, the thermodynamic parameters comprise the exhaust temperature and the suction temperature, and the frequency conversion parameters comprise the rotation speed ratio and the torque ratio; based on a pre-constructed total oil state evaluation model and the state parameters of the compressor, the oil distribution state of the compressor is determined; wherein the total oil state evaluation model is constructed based on thermodynamic parameter factors, frequency conversion parameter factors and the rotating speed of the compressor; state prediction and cosine correction are carried out based on the oil liquid distribution state of the compressor, and the change trend of oil liquid is obtained; and the opening degree of the electronic expansion valve, the rotating speed of the fan and the rotating speed of the compressor are adjusted based on the change trend of the oil and the distribution state of the oil. According to the invention, the oil liquid distribution uniformity can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioner control, and particularly to a control method, device, system and industrial control cabinet air conditioner for constant temperature oil return of an air conditioner. Background Art

[0002] Industrial cabinet air conditioners are mainly used to dissipate heat from electrical equipment in industrial cabinets to ensure the stable operation of the equipment in a suitable temperature environment. In the refrigeration system of an industrial cabinet air conditioner, the compressor compresses the refrigerant into a high-temperature and high-pressure gas, which becomes a liquid after being cooled by the condenser, and then enters the evaporator to absorb heat and evaporate after passing through a throttling device to reduce the pressure. In this process, the lubricating oil in the refrigeration system circulates in the system together with the refrigerant. Oil return refers to returning the lubricating oil that circulates to various parts of the system along with the refrigerant to the crankcase of the compressor through a certain method and route to ensure the normal lubrication and operation of the compressor.

[0003] The current oil return methods mainly include two types: timed oil return and single-parameter controlled oil return. The timed oil return method is a simple but effective auxiliary oil return means, often used in combination with methods such as gravity oil equalization. Its principle is to periodically open the oil return solenoid valve at set time intervals to forcibly supplement lubricating oil to each compressor to avoid lubrication failure caused by uneven oil quantity. The single-parameter controlled oil return method refers to an oil return method based only on temperature or pressure feedback. By monitoring the temperature or air pressure in real time, the lubricating oil separated by the temperature difference or pressure difference drop is returned to the crankcase of the compressor.

[0004] However, although the timed oil return method is simple, it will cause temperature fluctuations and cannot adapt to dynamic load changes. The single-parameter controlled oil return method is extremely prone to ignoring the coupling effects of key parameters such as rotational speed and torque due to relying only on temperature or pressure feedback. Summary of the Invention

[0005] Embodiments of the present invention provide a control method, device, system and industrial control cabinet air conditioner for constant temperature oil return of an air conditioner to solve the problem that the current oil return control method cannot track the changes in the operating conditions of the compressor in real time, resulting in uneven oil distribution.

[0006] In a first aspect, embodiments of the present invention provide a control method for constant temperature oil return of an air conditioner, including:

[0007] Obtaining the state parameters of the compressor of the target air conditioner; wherein, the state parameters include thermodynamic parameters and frequency conversion parameters, the thermodynamic parameters include exhaust temperature and suction temperature, and the frequency conversion parameters include speed ratio and torque ratio;

[0008] Based on a pre - constructed total oil - fluid state evaluation model and the state parameters of the compressor, determine the oil - fluid distribution state of the compressor; wherein, the total oil - fluid state evaluation model is constructed based on thermodynamic parameter factors, frequency - conversion parameter factors, and the rotational speed of the compressor.

[0009] Based on the oil - fluid distribution state of the compressor, conduct state prediction and cosine correction to obtain the change trend of the oil - fluid.

[0010] Based on the change trend of the oil - fluid and the oil - fluid distribution state, adjust the opening degree of the electronic expansion valve, the rotational speed of the fan, and the rotational speed of the compressor.

[0011] In a possible implementation manner, the total oil - fluid state evaluation model is constructed based on the sum of the product of the thermodynamic parameter factor and the first preset weight and the product of the frequency - conversion parameter factor and the second preset weight. The first preset weight is dynamically determined based on the rotational speed, and the sum of the first preset weight and the second preset weight is 1.

[0012] In a possible implementation manner, the thermodynamic parameter factor is determined by normalizing the temperature deviation based on a preset temperature, and the temperature deviation is the temperature difference between the exhaust and the suction.

[0013] The frequency - conversion parameter factor is constructed based on the sum of the product of the speed ratio and the third preset weight and the product of the torque ratio and the fourth preset weight. The sum of the third preset weight and the fourth preset weight is 1, and the third preset weight is greater than the fourth preset weight.

[0014] In a possible implementation manner, the first preset weight is the minimum value of the first parameter and the second parameter. The second parameter is determined by the sum of the third parameter and the fourth parameter, and the fourth parameter is determined by the product of the fifth parameter and the rotational speed. And the sum of the third parameter and the fifth parameter is equal to the first parameter.

[0015] In a possible implementation manner, based on the oil - fluid distribution state of the compressor, conduct state prediction and cosine correction to obtain the change trend of the oil - fluid, including:

[0016] Based on a pre - constructed predictive control model, correct the oil - fluid distribution state of the compressor to obtain the change trend of the oil - fluid.

[0017] Among them, the predictive control model includes a trend factor constructed by conducting linear regression analysis on historical data based on a sliding window and a cosine correction term determined based on suppressing the periodic start - stop of the compressor. The predictive control model is determined based on the product of the trend factor and the cosine correction term.

[0018] In a possible implementation manner, the trend factor is used to capture the change trend of the oil - fluid state, and the trend factor is the change rate of the oil - fluid distribution state over time within any time period.

[0019] In a possible implementation, based on the change trend of the oil fluid and the oil fluid distribution state, the opening degree of the electronic expansion valve, the rotational speed of the fan, and the rotational speed of the compressor are adjusted, including:

[0020] When the oil fluid distribution state is less than the first preset threshold or greater than the second preset threshold, the opening degree of the electronic expansion valve, the rotational speed of the condenser fan or the evaporator fan, and the rotational speed of the compressor are adjusted; wherein, the second preset threshold is greater than the first preset threshold.

[0021] When the change trend of the oil fluid is less than the third preset threshold or greater than the fourth preset threshold, a secondary alarm is triggered and oil return is performed; wherein, the fourth preset threshold is greater than the third preset threshold.

[0022] In a second aspect, an embodiment of the present invention provides a control device for air-conditioning constant-temperature oil return, including:

[0023] A parameter acquisition module for acquiring the state parameters of the compressor of the target air conditioner; wherein, the state parameters include thermodynamic parameters and frequency conversion parameters, the thermodynamic parameters include the exhaust temperature and the suction temperature, and the frequency conversion parameters include the speed ratio and the torque ratio.

[0024] A determination state module for determining the oil fluid distribution state of the compressor based on a pre-constructed total oil fluid state evaluation model and the state parameters of the compressor; wherein, the total oil fluid state evaluation model is constructed based on the thermodynamic parameters, the frequency conversion parameters, and the rotational speed of the compressor.

[0025] A prediction correction module for performing state prediction and cosine correction based on the oil fluid distribution state of the compressor to obtain the change trend of the oil fluid.

[0026] An adjustment module for adjusting the opening degree of the electronic expansion valve, the rotational speed of the fan, and the rotational speed of the compressor based on the change trend of the oil fluid and the oil fluid distribution state.

[0027] In a third aspect, an embodiment of the present invention provides a control system for air-conditioning constant-temperature oil return, including a sensor layer, a control layer, and an actuator layer;

[0028] The sensor layer is used to collect the state parameters of the compressor of the target air conditioner; the sensor layer includes an exhaust temperature sensor, a suction temperature sensor, a sensor for reading the rotational speed and torque.

[0029] The control layer is used to obtain the adjustment range of the opening degree of the electronic expansion valve, the adjustment range of the rotational speed of the fan, and the adjustment range of the rotational speed of the compressor based on the method of any item in the first aspect.

[0030] The actuator layer is used to adjust the electronic expansion valve, the fan, and the compressor based on the obtained adjustment range of the opening degree of the electronic expansion valve, the adjustment range of the rotational speed of the fan, and the adjustment range of the rotational speed of the compressor.

[0031] Fourthly, an industrial control cabinet air conditioner provided by an embodiment of the present invention includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the method in the first aspect above or any possible implementation manner of the first aspect is implemented.

[0032] Fifthly, a computer-readable storage medium provided by an embodiment of the present invention stores a computer program, and when the computer program is executed by a processor, the method in the first aspect above or any possible implementation manner of the first aspect is implemented.

[0033] Sixthly, a computer program product provided by an embodiment of the present invention includes a computer program, and when the computer program is executed by a processor, the method in the first aspect above or any possible implementation manner of the first aspect is implemented.

[0034] In the embodiment of the present invention, in order to be able to consider the influence of the coupling of multiple factors on the oil distribution, first, the state parameters of the compressor of the target air conditioner are obtained. Then, based on the pre-constructed total oil state evaluation model and the state parameters of the compressor, the oil distribution state of the compressor is determined. Among them, the total oil state evaluation model is constructed based on thermodynamic parameter factors, frequency conversion parameter factors, and the rotational speed of the compressor, so that the influence of multiple factors can be comprehensively considered and the oil distribution state can be reflected. Then, based on the oil distribution state of the compressor, state prediction and cosine correction are performed to obtain the change trend of the oil. Finally, based on the change trend of the oil and the oil distribution state, the opening degree of the electronic expansion valve, the rotational speed of the fan, and the rotational speed of the compressor are adjusted. Thus, the influence of multi-parameter fusion on the oil distribution can be considered, and the oil return can be controlled more accurately. The present invention is applicable to scenarios such as industrial cabinets and data centers that need to strictly maintain a constant temperature (±0.5°C), so that the coordinated control of efficient oil return and temperature stability can be achieved. Description of the Drawings

[0035] Figure 1 is the implementation flowchart of the control method for constant temperature oil return of the air conditioner provided by the embodiment of the present invention;

[0036] Figure 2 is the structural schematic diagram of the control device for constant temperature oil return of the air conditioner provided by the embodiment of the present invention;

[0037] Figure 3 is the structural schematic diagram of the control system for constant temperature oil return of the air conditioner provided by the embodiment of the present invention;

[0038] Figure 4 is provided by the embodiment of the present invention Figure 3 control logic schematic diagram;

[0039] Figure 5 It is a schematic diagram of the industrial control cabinet air conditioner provided by an embodiment of the present invention. Detailed implementation manners

[0040] The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0041] As described in the background art, currently the oil return control method is only based on single-parameter feedback control, such as only relying on temperature or pressure for adjustment, and cannot adapt to multi-variable coupling, which is extremely likely to cause uneven oil distribution.

[0042] Refer to Figure 1 , which shows the implementation flowchart of the control method for constant-temperature oil return of the air conditioner provided by an embodiment of the present invention, and is described in detail as follows:

[0043] S110. Obtain the state parameters of the compressor of the target air conditioner.

[0044] Among them, the state parameters include thermodynamic parameters and frequency conversion parameters. The thermodynamic parameters include exhaust temperature and suction temperature, and the frequency conversion parameters include speed ratio and torque ratio.

[0045] Among them, the thermodynamic parameters are the exhaust temperature and suction temperature obtained based on the installed temperature sensors, and the speed and torque of the frequency converter are read through the Modbus RTU protocol. The speed ratio can be determined by the ratio of the actual speed to the rated speed, and the torque ratio can be determined by the ratio of the actual torque to the rated torque.

[0046] The temperature sensor can adopt NTC3950. It can be installed at the air outlet ≥20 cm away from the compressor outlet and be equipped with a heat insulation sleeve. At the air inlet, it can be closely attached to the wall of the suction pipe to avoid the interference of thermal radiation.

[0047] S120. Based on the pre-constructed total oil state evaluation model and the state parameters of the compressor, determine the oil distribution state of the compressor.

[0048] Among them, the total oil state evaluation model is constructed based on thermodynamic parameters, frequency conversion parameters and the speed of the compressor.

[0049] In some embodiments, in order to be able to comprehensively consider the influence of the coupling of temperature, speed ratio, torque ratio and speed on oil return and achieve uniform oil distribution, the present invention constructs a total oil state evaluation model. The total oil state evaluation model is constructed based on the sum of the product of the thermodynamic parameter factor and the first preset weight and the product of the frequency conversion parameter factor and the second preset weight. The first preset weight is dynamically determined based on the speed, and the sum of the first preset weight and the second preset weight is 1.

[0050] In this embodiment, the thermodynamic parameter factor is determined by normalizing the temperature deviation based on the preset temperature, and the temperature deviation is the temperature difference between the exhaust and the suction. The variable frequency parameter factor is constructed based on the sum of the product of the speed ratio and the third preset weight and the product of the torque ratio and the fourth preset weight. The sum of the third preset weight and the fourth preset weight is 1, and the third preset weight is greater than the fourth preset weight.

[0051] Among them, the first preset weight is the minimum value of the first parameter and the second parameter. The second parameter is determined by the sum of the third parameter and the fourth parameter. The fourth parameter is determined by the product of the fifth parameter and the speed, and the sum of the third parameter and the fifth parameter is equal to the first parameter.

[0052] The total oil fluid state evaluation model combines the thermodynamic parameters and the variable frequency parameters, and can dynamically quantify the oil fluid distribution state. Specifically, the total oil fluid state evaluation model is:

[0053] Soil=w*Sthermal+(1-w)*Svar;

[0054] Among them, Sthermal is the thermodynamic parameter factor, which is used to quantify the thermodynamic state of the oil fluid. Svar is the variable frequency parameter factor.

[0055]

[0056] ΔT=Texhaust-Tsuction is the difference between the compressor exhaust temperature and the suction temperature (unit: °C). 50°C is the reference temperature difference when the oil fluid distribution is optimal, which is calibrated through the industrial compressor design manual and experiments. 20 is the normalization coefficient of the temperature deviation, that is, mapping the actual temperature difference to the standard interval. 0.1 is the sensitivity coefficient, which controls the influence amplitude of the temperature difference on the state value. 0.1 and 20: Calibrated through bench tests to ensure that for every 20°C deviation, the standard deviation of the oil fluid distribution changes by about 5%.

[0057] The total oil fluid state evaluation model is used to represent the relationship between the oil fluid viscosity and the temperature difference. The oil fluid viscosity decreases as the temperature increases, that is, the larger ΔT is, the stronger the fluidity of the oil fluid is. When ΔT = 50°C, the distribution of the oil fluid between the evaporator and the compressor is the most uniform.

[0058] Exemplarily, if Texhaust = 70°C, Texhaust = 25°C:

[0059] ΔT=70 - 25=45°C.

[0060] Sthermal=1.0+0.1*(45 - 50) / 20=0.975.

[0061] It can be seen that the oil fluid viscosity is too high and the fluidity is insufficient, and the oil return force needs to be increased.

[0062] Svar = 0.7vr + 0.3τratio;

[0063] Wherein, vr is the speed ratio of the compressor, which needs to be normalized to 0 - 1. τratio is the torque ratio of the compressor, which needs to be normalized to 0 - 1.

[0064] The speed dominates the oil circulation, with a weight ratio of 0.7. High speeds (vr > 1) accelerate the oil flow, but may shorten the residence time in the evaporator. Low speeds (vr < 1) cause oil retention, and the oil return frequency needs to be reduced.

[0065] Exemplarily, if vr = 1.2 and τratio = 0.8, then

[0066] Svar = 0.7 * 1.2 + 0.3 * 0.8 = 0.84 + 0.24 = 1.08.

[0067] It can be concluded that the speed is 20% over - speed, the oil circulation is accelerated, and the oil return force needs to be appropriately reduced.

[0068] w = min(0.6, 0.4 + 0.2 * vr);

[0069] Under low - speed conditions (vr < 1.0), it is necessary to balance the thermodynamic and variable - frequency parameters. For example, when vr = 0.5, w = 0.5. Under high - speed conditions (vr ≥ 1.0): the weight of the thermodynamic parameters is increased to 60%, and the change in oil viscosity is more significant at high temperatures. When operating at high speeds, the increase in the exhaust temperature causes a drastic change in oil viscosity, and the thermodynamic parameters need to be responded to preferentially.

[0070] S130. Perform state prediction and cosine correction based on the oil distribution state of the compressor to obtain the change trend of the oil.

[0071] In some embodiments, the oil distribution state of the compressor can be corrected based on a pre - constructed predictive control model to obtain the change trend of the oil.

[0072] The predictive control model includes a trend factor constructed by performing linear regression analysis on historical data based on a sliding window and a cosine correction term determined based on suppressing the periodic start - stop of the compressor. The predictive control model is determined based on the product of the trend factor and the cosine correction term.

[0073] In this embodiment, the trend factor is used to capture the change trend of the oil state, and the trend factor is the change rate of the oil distribution state over time within any time period.

[0074] Specifically, the predictive control model is Poil = Soil * (1 + 0.2T) * C;

[0075] T = (Soil(t) - Soil(t - Δt)) / Δt, C = 0.5 + 0.5 * cos(Soil);

[0076] T is the trend factor, used to capture the changing trend of the oil fluid state, such as continuous deterioration or improvement. Δt can be equal to 10 seconds, and the coefficient 0.2 is determined through stability analysis to prevent overshoot.

[0077] C is the cosine correction term, which can suppress the fluctuations caused by the periodic start and stop of the compressor.

[0078] Exemplarily, when Soil = π, C = 0, which can completely cancel out the periodic interference.

[0079] If Poil > 1.5 or Poil < 0.6, trigger a secondary alarm and slow down the oil return.

[0080] S140. Based on the changing trend of the oil fluid and the oil fluid distribution state, adjust the opening degree of the electronic expansion valve, the rotational speed of the fan, and the rotational speed of the compressor.

[0081] In some embodiments, when the oil fluid distribution state is less than the first preset threshold or greater than the second preset threshold, adjust the opening degree of the electronic expansion valve, the rotational speed of the condenser fan or the evaporator fan, and the rotational speed of the compressor; wherein, the second preset threshold is greater than the first preset threshold.

[0082] The drive signal of the electronic expansion valve is a PWM signal (frequency 1 kHz), and the duty cycle of 0 - 100% corresponds to the valve body opening degree of 0 - 500 steps. The step - flow calibration is from fully closed (0 steps, 0 L / min) to fully open (500 steps, 50 L / min), and the intermediate points are fitted by a quadratic curve.

[0083] The fan includes a condenser fan and an evaporator fan. The condenser fan is controlled by a 0 - 10V analog signal for rotational speed, that is, 0V corresponds to 20% rotational speed and 10V corresponds to 100% rotational speed. The evaporator fan has the same configuration as the condenser fan, and the signal lines are independent to avoid interference.

[0084] The adjustment rule of the electronic expansion valve is:

[0085] Opening degree adjustment amount: ΔV = kp(Soil - 1.0) (kp is adapted according to the heat load).

[0086] Adaptive rule: kp = 0.05 at low heat load (<50%); kp = 0.10 at high heat load (≥50%). Overshoot protection: When the temperature deviation > 0.3°C, pause the oil return operation.

[0087] The fan compensation strategy is:

[0088] When the electronic expansion valve is closed smaller: increase the rotational speed of the condenser fan by 15% to enhance heat dissipation.

[0089] The electronic expansion valve opens wider: the rotational speed of the evaporator fan decreases by 10%, maintaining the stability of the supply air temperature.

[0090] The adjustment range of the opening degree of the electronic expansion valve is ±20%, and the adjustment range of the rotational speed of the fan is ±30%.

[0091] Control of the compressor:

[0092] The rate of change of the rotational speed is limited to ≤5% / second to avoid mechanical shock.

[0093] For the control method provided by the present invention, in order to be able to consider the influence of the coupling of multiple factors on the oil distribution, first, the state parameters of the compressor of the target air conditioner are obtained. Then, based on the pre-constructed total oil state evaluation model and the state parameters of the compressor, the oil distribution state of the compressor is determined. Among them, the total oil state evaluation model is constructed based on the thermodynamic parameter factor, the frequency conversion parameter factor, and the rotational speed of the compressor, so as to comprehensively consider the influence of multiple factors and reflect the oil distribution state. Then, based on the oil distribution state of the compressor, state prediction and cosine correction are performed to obtain the change trend of the oil. Finally, based on the change trend of the oil and the oil distribution state, the opening degree of the electronic expansion valve, the rotational speed of the fan, and the rotational speed of the compressor are adjusted. Thus, the influence of multi-parameter fusion on the oil distribution can be considered, and the oil return can be controlled more accurately. The present invention is applicable to scenarios such as industrial cabinets and data centers that need to strictly maintain a constant temperature (±0.5°C), so as to achieve the coordinated control of efficient oil return and temperature stability.

[0094] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0095] The following is an apparatus embodiment of the present invention. For the details not described in detail, reference can be made to the corresponding method embodiments above.

[0096] Figure 2 The structural schematic diagram of the control device for constant temperature oil return of the air conditioner provided by the embodiment of the present invention is shown. For the convenience of description, only the parts related to the embodiment of the present invention are shown, and the details are as follows:

[0097] As Figure 2 shown, the control device 200 for constant temperature oil return of the air conditioner includes:

[0098] A parameter acquisition module 210, configured to acquire the state parameters of the compressor of the target air conditioner; wherein, the state parameters include thermodynamic parameters and frequency conversion parameters, the thermodynamic parameters include the exhaust temperature and the suction temperature, and the frequency conversion parameters include the speed ratio and the torque ratio;

[0099] A determination status module 220, configured to determine the oil distribution status of the compressor based on a pre-constructed total oil status evaluation model and the status parameters of the compressor; wherein, the total oil status evaluation model is constructed based on thermodynamic parameters, frequency conversion parameters, and the rotational speed of the compressor;

[0100] A prediction correction module 230, configured to perform status prediction and cosine correction based on the oil distribution status of the compressor to obtain the change trend of the oil;

[0101] An adjustment module 240, configured to adjust the opening degree of the electronic expansion valve, the rotational speed of the fan, and the rotational speed of the compressor based on the change trend of the oil and the oil distribution status.

[0102] In a possible implementation manner, the total oil status evaluation model is constructed based on the sum of the product of a thermodynamic parameter factor and a first preset weight and the product of a frequency conversion parameter factor and a second preset weight. The first preset weight is dynamically determined based on the rotational speed, and the sum of the first preset weight and the second preset weight is 1.

[0103] In a possible implementation manner, the thermodynamic parameter factor is determined by normalizing the temperature deviation based on a preset temperature, and the temperature deviation is the temperature difference between the exhaust and the suction;

[0104] The frequency conversion parameter factor is constructed based on the sum of the product of a speed ratio and a third preset weight and the product of a torque ratio and a fourth preset weight. The sum of the third preset weight and the fourth preset weight is 1, and the third preset weight is greater than the fourth preset weight.

[0105] In a possible implementation manner, the first preset weight is the minimum value of a first parameter and a second parameter. The second parameter is determined by the sum of a third parameter and a fourth parameter, and the fourth parameter is determined by the product of a fifth parameter and the rotational speed. Moreover, the sum of the third parameter and the fifth parameter is equal to the first parameter.

[0106] In a possible implementation manner, the prediction correction module 230 is configured to correct the oil distribution status of the compressor based on a pre-constructed prediction control model to obtain the change trend of the oil;

[0107] Wherein, the prediction control model includes a trend factor constructed by performing linear regression analysis on historical data based on a sliding window and a cosine correction term determined based on suppressing the periodic start and stop of the compressor. The prediction control model is determined based on the product of the trend factor and the cosine correction term.

[0108] In a possible implementation manner, the trend factor is used to capture the change trend of the oil status, and the trend factor is the change rate of the oil distribution status over time within any time period.

[0109] In a possible implementation, the adjustment module 240 is configured to adjust the opening degree of the electronic expansion valve, the rotation speed of the condenser fan or the rotation speed of the evaporator fan, and the rotation speed of the compressor when the oil distribution state is less than the first preset threshold or greater than the second preset threshold; wherein, the second preset threshold is greater than the first preset threshold.

[0110] When the change trend of the oil is less than the third preset threshold or greater than the fourth preset threshold, a secondary alarm is triggered and oil return is performed; wherein, the fourth preset threshold is greater than the third preset threshold.

[0111] In addition, as Figure 3 and 4 , the present invention further provides a control system for air-conditioning constant-temperature oil return, including a sensor layer, a control layer and an actuator layer.

[0112] The sensor layer is configured to collect the state parameters of the compressor of the target air conditioner; the sensor layer includes an exhaust temperature sensor, a suction temperature sensor, and sensors for reading the rotation speed and torque.

[0113] The control layer is configured to obtain the adjustment range of the opening degree of the electronic expansion valve, the adjustment range of the rotation speed of the fan, and the adjustment range of the rotation speed of the compressor based on the method of any item in the first aspect.

[0114] The actuator layer is configured to adjust the electronic expansion valve, the fan and the compressor based on the obtained adjustment range of the opening degree of the electronic expansion valve, the adjustment range of the rotation speed of the fan, and the adjustment range of the rotation speed of the compressor.

[0115] Wherein, as Figure 3 shown, the control layer includes a decision processor and an execution controller. The sensor layer includes an exhaust temperature sensor, a suction temperature sensor, and also includes a data interface of the frequency converter. The exhaust temperature sensor, the suction temperature sensor, and the data interface of the frequency converter are all connected to the decision processor. The decision processor is connected to the execution controller, and the execution controller is connected to the electronic expansion valve, the condenser fan, the internal circulation fan and the compressor.

[0116] The control logic of the control system for air-conditioning constant-temperature oil return is as Figure 4 shown. After receiving the state parameters of the sensor, the decision processor will perform multi-parameter fusion evaluation based on the total oil state evaluation model in the determination state module of the air-conditioning constant-temperature oil return control device and the state parameters of the compressor, and will also perform prediction model correction based on the prediction correction module. The decision processor outputs a control instruction to the execution controller based on the obtained change trend of the oil and the oil distribution state. The execution controller will control the operation of the electronic expansion valve, the fan and the compressor based on the obtained instruction.

[0117] Figure 5 is a schematic diagram of an industrial control cabinet air conditioner provided by an embodiment of the present invention. AsFigure 5 As shown in the figure, the industrial control cabinet air conditioner 5 of this embodiment includes: a processor 50 and a memory 51. The memory 51 stores a computer program 52. When the processor 50 executes the computer program 52, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor 50 executes the computer program 52, the functions of each module / unit in the above-mentioned device embodiments are implemented.

[0118] Exemplarily, the computer program 52 can be divided into one or more modules / units. The one or more modules / units are stored in the memory 51 and executed by the processor 50 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 52 in the industrial control cabinet air conditioner 5.

[0119] The industrial control cabinet air conditioner 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art can understand that Figure 5 This is only an example of the industrial control cabinet air conditioner 5, and does not constitute a limitation on the industrial control cabinet air conditioner 5. It may include more or fewer components than shown in the figure, or combine some components, or different components. For example, the industrial control cabinet air conditioner 5 may further include input / output devices, network access devices, buses, etc.

[0120] The processor 50 may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0121] The memory 51 can be an internal storage unit of the industrial control cabinet air conditioner 5, such as the hard disk or memory of the industrial control cabinet air conditioner 5. The memory 51 can also be an external storage device of the industrial control cabinet air conditioner 5, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the industrial control cabinet air conditioner 5. Further, the memory 51 can also include both the internal storage unit of the industrial control cabinet air conditioner 5 and the external storage device. The memory 51 is used to store the computer program 52 and other programs and data required by the industrial control cabinet air conditioner 5. The memory 51 can also be used to temporarily store the data that has been output or will be output.

[0122] For the convenience and simplicity of description, only the above-mentioned division of each functional module / unit is used as an example. In actual applications, the above functions can be assigned to different functional modules / units according to needs. The above-mentioned module / unit can be implemented in the form of hardware, or in the form of software, or in the form of a combination of hardware and software.

[0123] The embodiment of the present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the methods in the above-mentioned method embodiments are implemented.

[0124] The embodiment of the present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the methods in the above-mentioned method embodiments are implemented.

[0125] Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0126] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. Without special instructions and logical conflicts, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0127] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A control method for constant-temperature oil return of an air conditioner, characterized in that, Including: Obtain the state parameters of the compressor of the target air conditioner; wherein, the state parameters include thermodynamic parameters and frequency conversion parameters, the thermodynamic parameters include exhaust temperature and suction temperature, and the frequency conversion parameters include speed ratio and torque ratio; Based on the pre-constructed total oil liquid state evaluation model and the state parameters of the compressor, determine the oil liquid distribution state of the compressor; wherein, the total oil liquid state evaluation model is constructed based on thermodynamic parameter factors, frequency conversion parameter factors and the speed of the compressor; Perform state prediction and cosine correction based on the oil liquid distribution state of the compressor to obtain the change trend of the oil liquid; Adjust the opening degree of the electronic expansion valve, the speed of the fan and the speed of the compressor based on the change trend of the oil liquid and the oil liquid distribution state.

2. The control method for air conditioner constant temperature oil return according to claim 1, characterized in that The total oil liquid state evaluation model is constructed based on the sum of the product of the thermodynamic parameter factor and the first preset weight and the product of the frequency conversion parameter factor and the second preset weight. The first preset weight is dynamically determined based on the speed, and the sum of the first preset weight and the second preset weight is 1.

3. The control method for constant-temperature oil return of an air conditioner according to claim 2, characterized in that The thermodynamic parameter factor is determined by normalizing the temperature deviation based on a preset temperature, and the temperature deviation is the temperature difference between the exhaust and the suction; The frequency conversion parameter factor is constructed based on the sum of the product of the speed ratio and the third preset weight and the product of the torque ratio and the fourth preset weight. The sum of the third preset weight and the fourth preset weight is 1, and the third preset weight is greater than the fourth preset weight.

4. The control method for air conditioner constant temperature oil return according to claim 2, characterized in that, The first preset weight is the minimum value of the first parameter and the second parameter. The second parameter is determined by the sum of the third parameter and the fourth parameter. The fourth parameter is determined by the product of the fifth parameter and the speed, and the sum of the third parameter and the fifth parameter is equal to the first parameter.

5. The control method for air-conditioning constant-temperature oil return according to claim 1, characterized in that The performing state prediction and cosine correction based on the oil liquid distribution state of the compressor to obtain the change trend of the oil liquid includes: Based on the pre-constructed predictive control model, correct the oil liquid distribution state of the compressor to obtain the change trend of the oil liquid; Wherein, the predictive control model includes a trend factor constructed by performing linear regression analysis on historical data based on a sliding window and a cosine correction term determined based on suppressing the periodic start and stop of the compressor. The predictive control model is determined based on the product of the trend factor and the cosine correction term.

6. The control method for constant-temperature oil return of an air conditioner according to claim 5, wherein The trend factor is used to capture the change trend of the oil liquid state, and the trend factor is the change rate of the oil liquid distribution state over time within any time period.

7. The control method for constant-temperature oil return of an air conditioner according to any one of claims 1 to 6, characterized in that The adjusting the opening degree of the electronic expansion valve, the speed of the fan and the speed of the compressor based on the change trend of the oil liquid and the oil liquid distribution state includes: When the oil liquid distribution state is less than the first preset threshold or greater than the second preset threshold, adjust the opening degree of the electronic expansion valve, the speed of the condenser fan or the evaporator fan, and the speed of the compressor; wherein, the second preset threshold is greater than the first preset threshold; When the change trend of the oil liquid is less than the third preset threshold or greater than the fourth preset threshold, trigger a secondary alarm and return oil; wherein, the fourth preset threshold is greater than the third preset threshold.

8. A control device for constant temperature oil return of an air conditioner, characterized in that, Including: A parameter acquisition module for acquiring the status parameters of the compressor of the target air conditioner; wherein, the status parameters include thermodynamic parameters and frequency conversion parameters, the thermodynamic parameters include the exhaust temperature and the suction temperature, and the frequency conversion parameters include the speed ratio and the torque ratio; A determination status module for determining the oil distribution status of the compressor based on a pre-constructed total oil status evaluation model and the status parameters of the compressor; wherein, the total oil status evaluation model is constructed based on thermodynamic parameters, frequency conversion parameters and the speed of the compressor; A prediction correction module for performing status prediction and cosine correction based on the oil distribution status of the compressor to obtain the change trend of the oil; An adjustment module for adjusting the opening degree of the electronic expansion valve, the speed of the blower and the speed of the compressor based on the change trend of the oil and the oil distribution status.

9. A control system for constant-temperature oil return of an air conditioner, characterized in that, Including a sensor layer, a control layer and an actuator layer; The sensor layer is used for collecting the status parameters of the compressor of the target air conditioner; the sensor layer includes an exhaust temperature sensor, a suction temperature sensor, and sensors for reading the speed and torque; The control layer is used for obtaining the adjustment range of the opening degree of the electronic expansion valve, the adjustment range of the speed of the blower and the adjustment range of the speed of the compressor based on the method described in any one of claims 1-7; The actuator layer is used for adjusting the electronic expansion valve, the blower and the compressor based on the obtained adjustment range of the opening degree of the electronic expansion valve, the adjustment range of the speed of the blower and the adjustment range of the speed of the compressor.

10. An industrial control cabinet air conditioner, characterized in that, Including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the method described in any one of claims 1 to 7 is implemented.

Images