Control method of one-driving-two heat pump air conditioning system
By integrating the vehicle's waste heat through a dual-heat pump air conditioning system, the problems of insufficient low-temperature heating capacity and high energy consumption in new energy vehicles have been solved, resulting in reduced energy consumption and increased driving range.
Patent Information
- Application Number
- CN202510995703.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-18
- Publication Date
- 2025-11-21
AI Technical Summary
New energy vehicles have insufficient heating capacity in low-temperature conditions, high energy consumption of air conditioning systems, and excessive energy consumption when the battery cooling and heating systems are running simultaneously, which also occupies interior space.
The system employs a dual-split heat pump air conditioning system, which uses components such as a compressor, cooling solenoid valve, heating solenoid valve, external condenser, check valve, electronic expansion valve, and plate heat exchanger, combined with temperature and pressure sensors, to achieve cooling and heating cycle control and reduce energy consumption by utilizing battery waste heat.
It effectively integrates waste heat from the vehicle system, reduces overall energy consumption, increases driving range, simplifies system structure, and saves interior space.
Smart Images
Figure CN120986147A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of vehicle thermal management, in particular to a control method of a one-to-two heat pump air conditioning system. BACKGROUND
[0002] With the continuous improvement of global energy saving and environmental protection requirements, the automobile industry also faces great pressure to reduce energy consumption. Traditional fuel vehicles need to reduce fuel consumption and carbon emissions, while new energy vehicles urgently need to solve the problem of significant reduction in cruising range caused by high energy consumption for heating in winter. In the process of vehicle energy consumption, the vehicle interior environment control system accounts for a high proportion, second only to the power system, especially in low temperature conditions and hot environments, its energy consumption proportion increases significantly. At present, new energy vehicles usually use ptc heaters for heating in winter due to the unavailability of engine waste heat, which has low efficiency, resulting in a reduction of about 50% in cruising range. Some use air source heat pump systems, but the heating capacity is insufficient in low temperature conditions, and the system stability is difficult to guarantee.
[0003] Technical problems of prior art: 1. In the transition season and winter, the vehicle needs heating and battery cooling at the same time, and the battery cooling system and the heating system run at the same time, which has high energy consumption and increases the use cost.
[0004] 2. When the ambient temperature is low in winter, the heating efficiency of the ordinary air source heat pump is very low, and it is difficult to meet the customer's heating demand, and the customer's experience of air conditioning is very poor. In addition, electric heating needs to increase heating equipment, which occupies the space in the vehicle. SUMMARY
[0005] The technical problem to be solved by the present application is to effectively integrate and utilize the waste heat of the automobile system, reduce the overall energy consumption, and increase the cruising range of the automobile. To solve the above problems, a control method of a one-to-two heat pump air conditioning system is provided.
[0006] The purpose of the present application is achieved in the following manner: A control method of a one-to-two heat pump air conditioning system, The heat pump air conditioning system comprises a compressor 1, a refrigeration electromagnetic valve 2, a heating electromagnetic valve 3, an outside condenser 4, a first one-way valve 5, a second one-way valve 6, a first electronic expansion valve 7, a second electronic expansion valve 8, a plate heat exchanger 9, an air conditioning box 10, and a gas-liquid separator 11; the air conditioning box 10 is internally integrated with an inside condenser, an inside evaporator, a PTC auxiliary heater, and a blower; the exhaust port of the compressor 1 is divided into two paths, one path is connected to the outside condenser 4 through the refrigeration electromagnetic valve 2, and the other end of the outside condenser 4 is connected to the first one-way valve 5; the other path is connected to the inside condenser in the air conditioning box 10 through the heating electromagnetic valve 3, and the other end of the inside condenser is connected to the second one-way valve 6; the other ends of the first one-way valve 5 and the second one-way valve 6 are respectively connected to one end of the first electronic expansion valve 7 and the second electronic expansion valve 8, the other end of the first electronic expansion valve 7 is connected to the inside evaporator in the air conditioning box 10, and the other end of the inside evaporator is connected to the inlet of the gas-liquid separator; the other end of the second electronic expansion valve 8 is connected to the plate heat exchanger, the other end of the plate heat exchanger is connected to the inlet of the gas-liquid separator 11, and the outlet of the gas-liquid separator 11 is connected to the suction port of the compressor 1; the plate heat exchanger is also connected to an automobile water system circuit; The control method comprises a refrigeration cycle operation method and a heating cycle operation method; The refrigeration cycle operation method comprises: The inside temperature ta is collected by an inside temperature sensor, and the water temperature tw is collected by a temperature sensor arranged in the automobile water system circuit; It is judged whether the inside temperature ta is greater than a set value; If the inside temperature ta is not greater than the set value, only the battery refrigeration is opened, the first electronic expansion valve 7 is closed, the second electronic expansion valve 8 is opened, the refrigeration electromagnetic valve 2 is opened, the heating electromagnetic valve 3 is closed, the compressor 1 is opened, and the system cold quantity control module adjusts the compressor speed and the opening degree of the second electronic expansion valve 8; If the inside temperature ta is greater than the set value, it is judged whether the water temperature tw is greater than a set value; If the water temperature tw is greater than the set value, the air conditioner and the battery refrigerate simultaneously, the first electronic expansion valve 7 and the second electronic expansion valve 8 are opened simultaneously, the refrigeration electromagnetic valve 2 is opened, the heating electromagnetic valve 3 is closed, the compressor 1 is opened, and the system cold quantity control module adjusts the compressor speed and the opening degrees of the first electronic expansion valve 7 and the second electronic expansion valve 8; If the water temperature tw is not greater than the set value, only the air conditioner refrigeration is opened, the first electronic expansion valve 7 is opened, the second electronic expansion valve 8 is closed, the refrigeration electromagnetic valve 2 is opened, the heating electromagnetic valve 3 is closed, the compressor 1 is opened, and the system cold quantity control module adjusts the compressor speed and the opening degree of the first electronic expansion valve 7; The heating cycle operation method comprises: The inside temperature ta and the water temperature tw are collected; determining whether the temperature ta in the vehicle is greater than a set value, and if not, determining whether the water temperature tw is less than a set value; if the water temperature tw is less than the set value, the liquid heat PTC in the water system circuit of the vehicle is opened; if the water temperature tw is not less than the set value, the first electronic expansion valve 7 is closed, the second electronic expansion valve 8 is opened, the refrigeration solenoid valve 2 is closed, the heating solenoid valve 3 is opened, and the system heat control module adjusts the compressor speed and the electronic expansion valve opening degree.
[0007] The control method of the system cold control module comprises the following steps: A1: collecting the suction pressure pl, the discharge pressure ph, the suction temperature tx, the discharge temperature tp, the compressor speed n, and the electronic expansion valve opening degree k through the temperature sensor and the pressure sensor arranged at the suction port and the discharge port of the compressor respectively; the electronic expansion valve comprises the first electronic expansion valve 7 and the second electronic expansion valve 8; A2: whether to open the air conditioner refrigeration and the battery refrigeration simultaneously; A3: if the refrigeration is opened simultaneously, calculating the plate heat exchanger suction superheat twsh, and calculating the plate heat exchanger suction superheat deviation deltTwsh, A4: controlling the second electronic expansion valve 8 opening degree by using the PI controller according to the plate heat exchanger superheat deviation deltTwsh, and compensating the valve opening degree by using the superheat deviation correction value e; A5: if the refrigeration is opened simultaneously, calculating the air conditioner suction superheat tash; calculating the air conditioner suction superheat deviation deltTash; A6: controlling the first electronic expansion valve 7 opening degree by using the PI controller according to the air conditioner suction superheat deviation deltTash, and compensating the valve opening degree by using the superheat deviation correction value e; A7: calculating the water temperature tw and the set temperature deviation deltTw; A8: calculating the vehicle temperature ta and the set temperature deviation deltTa; A9: calculating the compressor speed n by using the PID algorithm according to deltTw and deltTa; calculating the compressor speed n by using the PID algorithm according to deltTa; A10: determining whether the discharge pressure ph is less than a set value, A11: if the discharge pressure ph is not less than the set value; adjusting the compressor speed n by using the proportional integral algorithm according to the difference between ph and the high pressure set value phs; calculating the electronic expansion valve superheat deviation correction value e by using the proportional algorithm according to the compressor speed n, and returning to steps A4 and A6 respectively; A12: If the exhaust pressure ph is less than the set value; according to the compressor speed n, the proportional algorithm is used to calculate the electronic expansion valve superheat deviation correction value e, and then return to steps A4 and A6 respectively; A13: If it is not the same open refrigeration, only single open air conditioning refrigeration, then A8-A12 steps are performed; A14: If it is not the same open refrigeration, only single open battery refrigeration, then the water temperature tw and the deviation deltTw of the set temperature are calculated; According to deltTw, the compressor speed n is calculated by using PID algorithm, and then A10-A12 steps are performed.
[0008] The compressor speed regulation in refrigeration mode includes: Collecting the suction pressure pl, the exhaust pressure ph, the suction temperature tx, the exhaust temperature tp, the vehicle temperature ta, and the water temperature tw; B: If the exhaust pressure Ph is greater than the set value, and is single open battery refrigeration, then the compressor speed n2(t-1) at the last time is recorded, and the water temperature tw and the set temperature deviation deltTw(t-1) and deltTw(t-2) at the last two sampling times are recorded respectively; The deviation deltTw(t) of the current time water temperature tw and the set temperature tws is calculated; The deviation coefficient a(t) of the current time is calculated: a(t)=Kp(1+deltTao / 2 / Ti+Td / deltTao); The deviation coefficients of the last two times are calculated respectively: a(t-1)=Kp(deltTao / 2 / Ti-2Td / deltTao-1); a(t-2)=Kp*Td / deltTao The compressor speed increment deltN2 is calculated: deltN2=a(t)*deltTa(t)+a(t-1)*deltTa(t-1)+a(t-2)*deltTa(t-2); The compressor speed n2(t) is calculated: n2(t)=n2(t-1)+deltN2; C: If the exhaust pressure Ph is greater than the set value, and is single open air conditioning refrigeration, then the compressor speed n1(t-1) at the last time is recorded, and the vehicle temperature ta and the set temperature deviation deltTa(t-1) and deltTa(t-2) at the last two sampling times are recorded respectively; The deviation deltTa(t) of the current time vehicle temperature ta and the set temperature tas is calculated; The deviation coefficient a(t) of the current time is calculated: a(t)=Kp(1+deltTao / 2 / Ti+Td / deltTao); Calculate the deviation coefficient of the previous two time points respectively: a(t-1)=Kp(deltTao / 2 / Ti-2Td / deltTao-1); a(t-2)=Kp*Td / deltTao; Calculate the compressor speed increment: deltN1=a(t)*deltTa(t)+a(t-1)*deltTa(t-1)+a(t-2)*deltTa(t-2); Calculate the compressor speed: n1(t)=n1(t-1)+deltN1; D: If the exhaust pressure Ph is greater than the set value, and the battery cooling and air conditioning cooling are turned on at the same time, Calculate the current compressor total speed: n(t)=n1(t)+n2(t); E: If the exhaust pressure Ph is not greater than the set value: Record the compressor total speed n(t-1) at the previous time, and record the high-pressure exhaust pressure ph at the previous sampling time and the set upper limit deviation deltP(t-1); Calculate the high-pressure exhaust pressure ph at the current time and the set upper limit deviation deltP(t); Calculate the deviation coefficient at the current time: b(t)=Kp(1+deltTao / 2 / Ti); Calculate the deviation coefficient at the previous time: b(t-1)=Kp(deltTao / 2 / Ti-1); Calculate the compressor speed increment: deltN= b(t) * deltP(t) + b(t-1)* deltP(t-1); Calculate the compressor speed: n(t)=n(t-1)+deltN; Where Kp is the proportional gain, Ti is the integral time, Td is the derivative time, and deltTao is the sampling period.
[0009] The electronic expansion valve opening degree adjustment module includes: Collect the suction pressure pl, the exhaust pressure ph, the suction temperature tx, and the exhaust temperature tp; Input the current compressor speed n(t), record the opening degree M(t-1) and the speed n(t-1) at the previous time; Calculate the superheat deviation correction value E_x: E_x = (n(t) - n(t-1)) / n(t-1) / 0.003 / (kp+kp*deltTtao / Ti); Calculate the suction gas saturation temperature te according to the suction gas pressure pl (according to the refrigerant property table) Calculate the suction gas superheat degree deltTsh: deltTsh = tx - te; Calculate the deviation of the suction gas superheat degree from the set value deltTshs: E_tsh = deltTsh - deltTshs; Calculate the corrected suction gas superheat degree deviation: E(t) = E_tsh + E_x; Calculate the superheat degree deviation correction coefficient c(t) at the current time: c(t) = kp + kp*deltTao / 2 / Ti; Calculate the superheat degree deviation correction coefficient c(t-1) at the previous time: c(t-1) = -kp + kp*deltTao / 2 / Ti; Calculate the electronic expansion valve opening increment: DeltM = c(t)*E(t) + c(t-1)*E(t-1); Calculate the electronic expansion valve opening: M(t) = M(t-1) + DeltM; Determine whether the electronic expansion valve M(t) is out of limit; If it is out of limit, take the limit value for M(t); If it is not out of limit, output M(t); Where kp is the proportional gain, Ti is the integral time, and deltTao is the sampling period.
[0010] The control method of the system heating capacity control module includes: Collect the suction gas pressure pl, the discharge gas pressure ph, the suction gas temperature tx, the discharge gas temperature tp, the compressor speed n, the electronic expansion valve opening k, and the outlet air temperature tout; Calculate the deviation deltTa of the indoor temperature ta and the set temperature; Calculate the deviation deltP of the current high-pressure discharge gas pressure ph and the set discharge gas pressure phs; Calculate the deviation deltTso of the outlet air temperature tout and the set value tsout; F: If deltTso ≥ 0 and deltP < 0, then Calculate the plate heat exchanger suction gas superheat degree twsh; Calculate the plate heat exchanger suction gas superheat degree deviation deltTwsh; PID algorithm is used to calculate the compressor speed n according to deltaT; A proportional algorithm is used to calculate the second electronic expansion valve 8 superheat deviation correction value e according to n; A PI controller is used to control the second electronic expansion valve 8 opening degree according to deltaTwsb, and the valve opening degree is compensated and controlled by the superheat deviation correction value e; If deltaTso≥0, deltaP≥0, 0Mpa≤deltaP≤0.2Mpa, then The first electronic expansion valve 7 is opened to bypass the refrigerant to the indoor evaporator; The first electronic expansion valve 7 opening degree is controlled by a proportional weighting algorithm according to the indoor evaporator superheat and deltaP, and the maximum opening degree is limited; If deltaTso≥0, deltaP≥0, 0.2Mpa If deltaTso≥0, deltaP≥0, deltaP≤0.2Mpa or 0.5Mpa
[0011] The compressor speed regulation in heat pump mode includes: The suction pressure pl, discharge pressure ph, suction temperature tx, discharge temperature tp, indoor temperature ta, and water temperature tw are collected; The deviation difference deltaP of the current high-pressure discharge pressure ph from the set value phs is calculated; If deltaP≤0, then The compressor speed n1(t-1) at the last time is recorded, and the indoor temperature ta and the set temperature deviation deltaTao(t-1) and deltaTao(t-2) at the last two sampling times are recorded respectively, The indoor temperature ta and the set temperature tas deviation deltaTao(t) at the current time is calculated, The deviation coefficients at the last two times are calculated respectively: a(t-1)=Kp(deltTao / 2 / Ti-2Td / deltTao-1), a(t-2)=Kp*Td / deltTao; The compressor speed increment is calculated: deltN1=a(t)*deltTao(t)+a(t-1)*deltTao(t-1)+a(t-2)*deltTao(t-2); The compressor speed is calculated: n1(t)=n1(t-1)+deltN1; If deltP≥0, 0 If deltP≥0, 0.2 Record the compressor total speed n(t-1) at the last sampling time, and record the high pressure ph and the set upper limit deviation deltP(t-1) at the last sampling time, Calculate the deviation deltP(t) between the current high pressure ph and the set upper limit, Calculate the deviation coefficient at the current time: b(t)=Kp(1+deltTao / 2 / Ti), Calculate the deviation coefficient at the last time: b(t-1)=Kp(deltTao / 2 / Ti-1), Calculate the compressor speed: n(t)=n(t-1)+deltN. If it is not 0.2 Calculate the deviation deltP(t) between the current high pressure ph and the set upper limit, Calculate the deviation coefficient at the current time: b(t)=Kp(1+deltTao / 2 / Ti), Calculate the deviation coefficient at the last time: b(t-1)=Kp(deltTao / 2 / Ti-1), Calculate the compressor speed: n(t)=n(t-1)+deltN.
[0012] Heating bypass electronic expansion valve opening control module: Collect the suction pressure pl, the discharge pressure ph, the suction temperature tx, and the discharge temperature tp; Record the opening M(t-1) at the last time; Calculate the deviation deltP(t) between the current high pressure ph and the set value phs; Calculate the suction saturation temperature te according to the suction pressure pl, which is obtained according to the refrigerant property table Calculate the suction superheat deltTsh; deltTsh=tx-te; Calculate the deviation between the suction superheat and the set value deltTshs: E_tsh(t)=deltTsh-deltTshs; Calculate electronic expansion valve opening increment: DeltM1=kp(E_tsh(t)-E_tsh(t-1)), Calculate electronic expansion valve opening 1: M1(t)=M(t-1)+deltM; Calculate the deviation of the current high-pressure exhaust gas pressure ph from the set value phs Calculate electronic expansion valve opening increment: deltM2=kp(deltP(t)-deltP(t-1)), Calculate electronic expansion valve opening 2: M2(t)=M(t-1)+deltM2, Calculate electronic expansion valve opening Mt=a*M1(t)+(1-a)M2(t); Where kp is the proportional gain, and a is the weight coefficient.
[0013] The second electronic expansion valve (8) opening control module during heating includes: Collecting the suction pressure pl, the exhaust gas pressure ph, the suction temperature tx, and the exhaust gas temperature tp; Inputting the current compressor speed n(t), recording the opening M(t-1) and the speed n(t-1) at the previous time; Calculate the superheat deviation correction value E_x: E_x=(n(t)-n(t-1)) / n(t-1) / 0.003 / (kp+kp*deltTtao / Ti); Calculate the suction saturation temperature te according to the suction pressure pl, which is obtained according to the refrigerant property table, Calculate the suction superheat deltTsh: deltTsh=tx-te; Calculate the deviation of the suction superheat from the set value deltTshs: E_tsh=deltTsh-deltTshs; Calculate the corrected suction superheat deviation: E(t)=E_tsh+E_x; Calculate the current time superheat deviation correction coefficient c(t): c(t)=kp+kp*deltTao / 2 / Ti; Calculate the superheat deviation correction coefficient c(t-1) at the previous time: c(t-1) = -kp + kp * deltTao / 2 / Ti Calculate electronic expansion valve opening increment: DeltM = c(t) * E(t) + c(t-1) * E(t-1) Calculate electronic expansion valve opening: M(t) = M(t-1) + DeltM Judge whether electronic expansion valve M(t) is out of limit; If out of limit, M(t) takes limit value; If not out of limit, output M(t); Wherein, kp is proportional gain, Ti is integral time, and deltTao is sampling period.
[0014] The application has the advantages that the application recovers battery waste heat through a heat pump method, reduces heat pump operation energy consumption in winter and transition season, maintains appropriate battery temperature, and improves cruising range; the application uses one compressor to simultaneously realize air conditioning box and battery cooling and vehicle interior heating, uses valve switching to realize different functions, has high integration degree, and has flexible and simple system and saves vehicle interior use space. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is a heat pump air conditioning system principle diagram.
[0016] Figure 2 is a mode control principle diagram.
[0017] Figure 3 is a refrigeration cycle operation module flow chart.
[0018] Figure 4 is a heating cycle operation module flow chart.
[0019] Figure 5 is a system cold quantity control module flow chart.
[0020] Figure 6 is a refrigeration mode compressor rotating speed regulation flow chart.
[0021] Figure 7 is an electronic expansion valve opening regulation module flow chart.
[0022] Figure 8 is a system heating quantity control module flow chart.
[0023] Figure 9 is a heat pump compressor rotating speed control module flow chart Figure 10 is a heating time bypass electronic expansion valve opening control module flow chart.
[0024] Among them, 1-compressor; 2-refrigeration solenoid valve; 3-heating solenoid valve; 4-external condenser; 5-one-way valve; 6-one-way valve; 7-electronic expansion valve; 8-electronic expansion valve; 9-plate heat exchanger; 10-air conditioning unit; 11-gas-liquid separator. Detailed Implementation
[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0026] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same technical meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0027] like Figure 1 and Figure 2 As shown, a dual-split heat pump air conditioning system includes a compressor 1, a cooling solenoid valve 2, a heating solenoid valve 3, an external condenser 4, a first one-way valve 5, a second one-way valve 6, a first electronic expansion valve 7, a second electronic expansion valve 8, a plate heat exchanger 9, an air conditioning unit 10, and a gas-liquid separator 11. The air conditioning unit 10 integrates an internal condenser, an internal evaporator, a PTC electric heater, and a blower. The compressor 1's exhaust port is divided into two paths: one path connects to the external condenser 4 via the cooling solenoid valve 2, and the other end of the external condenser 4 connects to the first one-way valve 5; the other path connects to the heating solenoid valve 3. Solenoid valve 3 is connected to the vehicle interior condenser inside the air conditioning unit 10, and the other end of the vehicle interior condenser is connected to the second one-way valve 6; the other ends of the first one-way valve 5 and the second one-way valve 6 are respectively connected to one end of the first electronic expansion valve 7 and the second electronic expansion valve 8, the other end of the first electronic expansion valve 7 is connected to the vehicle interior evaporator inside the air conditioning unit 10, and the other end of the vehicle interior evaporator is connected to the inlet of the gas-liquid separator; the other end of the second electronic expansion valve 8 is connected to the plate heat exchanger, the other end of the plate heat exchanger is connected to the inlet of the gas-liquid separator 11, and the outlet of the gas-liquid separator 11 is connected to the suction port of the compressor 1.
[0028] In cooling mode, the high-temperature, high-pressure refrigerant gas discharged from compressor 1 enters the external condenser 4 through the cooling solenoid valve 2. After exchanging heat with the outside air, it condenses into a high-pressure, medium-temperature liquid refrigerant. Then, after passing through the first one-way valve 5, it splits into two paths. Branch 1 enters the first electronic expansion valve 7 and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant. Then, it enters the evaporator inside the air conditioning unit 10, where it evaporates and absorbs heat to become a low-temperature, low-pressure gaseous refrigerant, thereby lowering the temperature of the air inside the vehicle. Branch 2 enters the second electronic expansion valve 8 and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant. Then, it enters the plate heat exchanger 9 and exchanges heat with the vehicle's water system to become a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerants from the two branches merge and enter the compressor suction port through the gas-liquid separator 11, thus completing the cooling cycle.
[0029] In heating mode, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 enters the vehicle condenser inside the air conditioning unit 10 through the heating solenoid valve 3. After exchanging heat with the air inside the vehicle, it condenses into a high-pressure, medium-temperature liquid refrigerant. Then, after passing through the second one-way valve 6, it enters the second electronic expansion valve 8 and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant. Then, it enters the plate heat exchanger 9 and exchanges heat with the vehicle's water system to become a low-temperature, low-pressure gaseous refrigerant. Finally, it passes through the gas-liquid separator 11 and enters the compressor suction port, thus completing the heating cycle.
[0030] The control method includes a refrigeration cycle operation method and a heating cycle operation method; like Figure 3 As shown, the refrigeration cycle operation method includes: The vehicle interior temperature ta is collected by a temperature sensor installed inside the vehicle, and the water temperature tw is collected by a temperature sensor installed in the vehicle's water system circuit. Determine if the vehicle interior temperature ta is greater than the set value; If the interior temperature ta is not greater than the set value, the battery cooling will be turned on separately, the first electronic expansion valve 7 will be closed, the second electronic expansion valve 8 will be opened, the cooling solenoid valve 2 will be opened, the heating solenoid valve 3 will be closed, the compressor 1 will be turned on, and the system cooling capacity control module will adjust the compressor speed and the opening of the second electronic expansion valve 8. If the interior temperature ta is greater than the set value, then determine whether the water temperature tw is greater than the set value. If the water temperature tw is greater than the set value, the air conditioner and the battery will cool at the same time, the first electronic expansion valve 7 and the second electronic expansion valve 8 will open at the same time, the cooling solenoid valve 2 will open, the heating solenoid valve 3 will close, the compressor 1 will open, and the system cooling capacity control module will adjust the compressor speed and the opening degree of the first electronic expansion valve 7 and the second electronic expansion valve 8. If the water temperature tw is not greater than the set value, the air conditioner will be turned on for cooling only. The first electronic expansion valve 7 will be opened, the second electronic expansion valve 8 will be closed, the cooling solenoid valve 2 will be opened, the heating solenoid valve 3 will be closed, the compressor 1 will be turned on, and the system cooling capacity control module will adjust the compressor speed and the opening degree of the first electronic expansion valve 7. like Figure 4 As shown, the heating cycle operation method includes: Collect the vehicle interior temperature ta and the water temperature tw; Determine if the interior temperature ta is greater than the set value; if not, determine if the coolant temperature tw is less than the set value. If the water temperature tw is less than the set value, the liquid thermal PTC in the car's water system circuit will turn on; If the water temperature tw is not less than the set value, the first electronic expansion valve 7 is closed, the second electronic expansion valve 8 is opened, the refrigeration solenoid valve 2 is closed, the heating solenoid valve 3 is opened, and the system heat control module adjusts the compressor speed and the electronic expansion valve opening degree.
[0031] As shown in Figure 5 the control method of the system cold control module includes the following steps: A1: Collecting the suction pressure pl, the discharge pressure ph, the suction temperature tx, the discharge temperature tp, the compressor speed n, and the electronic expansion valve opening degree k through the temperature sensor and the pressure sensor arranged at the suction port and the discharge port of the compressor respectively; the electronic expansion valve includes the first electronic expansion valve 7 and the second electronic expansion valve 8; A2: Whether to open the air conditioner refrigeration and the battery refrigeration simultaneously; A3: If the refrigeration is opened simultaneously, calculating the plate heat exchanger suction superheat twsh, calculating the plate heat exchanger suction superheat deviation deltTwsh, A4: Controlling the second electronic expansion valve 8 opening degree by using the PI controller according to the plate heat exchanger superheat deviation deltTwsh, and compensating the valve opening degree by using the superheat deviation correction value e; A5: If the refrigeration is opened simultaneously, calculating the air conditioner suction superheat tash; calculating the air conditioner suction superheat deviation deltTash; A6: Controlling the first electronic expansion valve 7 opening degree by using the PI controller according to the air conditioner suction superheat deviation deltTash, and compensating the valve opening degree by using the superheat deviation correction value e; A7: Calculating the water temperature tw and the set temperature deviation deltTw; A8: Calculating the vehicle temperature ta and the set temperature deviation deltTa; A9: According to deltTw and deltTa, calculating the compressor speed n by using the PID algorithm; According to deltTa, calculating the compressor speed n by using the PID algorithm; A10: Judging whether the discharge pressure ph is less than the set value, A11: If the discharge pressure ph is not less than the set value; adjusting the compressor speed n by using the proportional integral algorithm according to the difference between ph and the high pressure set value phs; calculating the electronic expansion valve superheat deviation correction value e by using the proportional algorithm according to the compressor speed n, and returning to steps A4 and A6 respectively; A12: If the discharge pressure ph is less than the set value; calculating the electronic expansion valve superheat deviation correction value e by using the proportional algorithm according to the compressor speed n, and returning to steps A4 and A6 respectively; A13: If not the same open refrigeration; only single open air conditioning refrigeration, then A8-A12 steps; A14: If not the same open refrigeration, only single open battery refrigeration, then calculate the water temperature tw and the deviation of the set temperature deltTw; According to deltTw, the compressor speed n is calculated by PID algorithm, and then A10-A12 steps are performed.
[0032] As Figure 6 shown, the refrigeration mode compressor speed regulation includes: Collecting suction pressure pl, discharge pressure ph, suction temperature tx, discharge temperature tp, vehicle temperature ta, water temperature tw; B: If the discharge pressure Ph is greater than the set value, and is single open battery refrigeration, then record the compressor speed n2(t-1) at the last time, and record the water temperature tw at the last two sampling times respectively. The deviation deltTw(t-1) and deltTw(t-2) of the set temperature; Calculate the deviation deltTw(t) of the current time water temperature tw and the set temperature tws; Calculate the deviation coefficient of the current time: a(t)=Kp(1+deltTao / 2 / Ti+Td / deltTao); Calculate the deviation coefficient of the last two times respectively: a(t-1)=Kp(deltTao / 2 / Ti-2Td / deltTao-1); a(t-2)=Kp*Td / deltTao Calculate the compressor speed increment: deltN2=a(t)*deltTa(t)+a(t-1)*deltTa(t-1)+a(t-2)*deltTa(t-2); Calculate the compressor speed: n2(t)=n2(t-1)+deltN2; C: If the discharge pressure Ph is greater than the set value, and is single open air conditioning refrigeration, then record the compressor speed n1(t-1) at the last time, and record the vehicle temperature ta at the last two sampling times respectively. The deviation deltTa(t-1) and deltTa(t-2) of the set temperature; Calculate the deviation deltTa(t) of the current time vehicle temperature ta and the set temperature tas; Calculate the deviation coefficient of the current time: a(t)=Kp(1+deltTao / 2 / Ti+Td / deltTao); Calculate the deviation coefficient of the last two times respectively: a(t-1) = Kp(deltTao / 2 / Ti-2Td / deltTao-1); a(t-2) = Kp*Td / deltTao; Calculate the compressor speed increment: deltN1 = a(t)*deltTa(t) + a(t-1)*deltTa(t-1) + a(t-2)*deltTa(t-2); Calculate the compressor speed: n1(t) = n1(t-1) + deltN1; D: If the exhaust pressure Ph is greater than the set value, and the battery cooling and air conditioning cooling are turned on at the same time, then calculate the current compressor total speed: n(t) = n1(t) + n2(t); E: If the exhaust pressure Ph is not greater than the set value: Record the compressor total speed n(t-1) at the last time, and record the high-pressure exhaust pressure ph and the set upper limit deviation deltP(t-1) at the last sampling time; Calculate the high-pressure exhaust pressure ph and the set upper limit deviation deltP(t) at the current time; Calculate the deviation coefficient at the current time: b(t) = Kp(1+deltTao / 2 / Ti); Calculate the deviation coefficient at the last time: b(t-1) = Kp(deltTao / 2 / Ti-1); Calculate the compressor speed increment: deltN = b(t) * deltP(t) + b(t-1)* deltP(t-1); Calculate the compressor speed: n(t) = n(t-1) + deltN; Where Kp is the proportional gain, Ti is the integral time, Td is the derivative time, and deltTao is the sampling period.
[0033] As shown in Figure 7 The adjustment method of the first electronic expansion valve 7 and the second electronic expansion valve 8 is the same, and both use the following electronic expansion valve opening degree adjustment module for adjustment. The electronic expansion valve opening degree adjustment module includes: Collect the suction pressure pl, the exhaust pressure ph, the suction temperature tx, and the exhaust temperature tp; Input the current compressor speed n(t), record the opening degree M(t-1) and the speed n(t-1) at the last time; Calculate the superheat deviation correction value E_x: E_x = (n(t) - n(t-1)) / n(t-1) / 0.003 / (kp+kp*deltTtao / Ti); Calculate the suction gas saturation temperature te according to the suction gas pressure pl (according to the refrigerant property table) Calculate the suction gas superheat degree deltTsh: deltTsh = tx - te; Calculate the suction gas superheat degree deviation from the set value deltTshs: E_tsh = deltTsh - deltTshs; Calculate the corrected suction gas superheat degree deviation: E(t) = E_tsh + E_x; Calculate the current time superheat degree deviation correction coefficient c(t): c(t) = kp + kp*deltTao / 2 / Ti; Calculate the last time superheat degree deviation correction coefficient c(t-1): c(t-1) = -kp + kp*deltTao / 2 / Ti; Calculate the electronic expansion valve opening increment: DeltM = c(t)*E(t) + c(t-1)*E(t-1); Calculate the electronic expansion valve opening: M(t) = M(t-1) + DeltM; Determine whether the electronic expansion valve M(t) is out of limit; If it is out of limit, M(t) takes the limit value; If it is not out of limit, output M(t); Where kp is the proportional gain, Ti is the integral time, and deltTao is the sampling period.
[0034] As shown in Figure 8 The control method of the system heating capacity control module includes: Collect the suction gas pressure pl, the discharge gas pressure ph, the suction gas temperature tx, the discharge gas temperature tp, the compressor speed n, the electronic expansion valve opening k, and the outlet air temperature tout; Calculate the deviation deltTa of the indoor temperature ta and the set temperature; Calculate the deviation deltP of the current high-pressure discharge gas pressure ph and the set discharge gas pressure phs; Calculate the deviation deltTso of the outlet air temperature tout and the set value tsout; F: If deltTso≥0 and deltP<0, then Calculate the plate heat exchanger suction gas superheat degree twsh; Calculate the suction superheat deviation deltTwsh of the plate heat exchanger; Calculate the compressor speed n according to deltTa using the PID algorithm; Calculate the superheat deviation correction value e of the second electronic expansion valve 8 according to n using the proportional algorithm; Control the opening of the second electronic expansion valve 8 according to deltTwsh using a PI controller, and compensate and control the valve opening using the superheat deviation correction value e; If deltTso≥0, deltP≥0, 0Mpa≤deltP≤0.2Mpa, then Open the first electronic expansion valve 7 to bypass the refrigerant to the in-vehicle evaporator; The opening of the first electronic expansion valve 7 is controlled using the proportional weighted algorithm according to the superheat of the in-vehicle evaporator and deltP, and the maximum opening limit is set; If deltTso≥0, deltP≥0, 0.2Mpa<deltP≤0.5Mpa, then open the refrigeration solenoid valve 2 to dissipate heat through the out-of-vehicle condenser; If deltTso≥0, deltP≥0, deltP≤0.2Mpa or 0.5Mpa<deltP, adjust the compressor speed n using the proportional integral algorithm according to the effective deltP.
[0035] As Figure 9 shown, the regulation of the compressor speed in the heat pump mode includes: Collect the suction pressure pl, discharge pressure ph, suction temperature tx, discharge temperature tp, in-car temperature ta, and water temperature tw; Calculate the deviation deltP between the current high-pressure discharge pressure ph and the set value phs; If deltP≤0, then Record the compressor speed n1(t - 1) at the previous moment, and respectively record the deviations deltTa(t - 1) and deltTa(t - 2) between the in-car temperature ta and the set temperature at the previous two sampling moments, Calculate the deviation deltTa(t) between the in-car temperature ta and the set temperature tas at the current moment, Calculate the deviation deltTa(t) between the in-car temperature ta and the set temperature tas at the current moment, Calculate the deviation coefficients at the previous two moments respectively: a(t - 1)=Kp(deltTao / 2 / Ti - 2Td / deltTao - 1), a(t - 2)=Kp*Td / deltTao; Calculate the compressor speed increment: deltN1 = a(t) * deltTa(t) + a(t - 1) * deltTa(t - 1) + a(t - 2) * deltTa(t - 2); Calculate the compressor speed: n1(t) = n1(t - 1) + deltN1; If deltP ≥ 0 and 0 < deltP < 0.2, maintain the speed at the previous moment; If deltP ≥ 0 and 0.2 ≤ deltP < 0.5, then Record the total compressor speed n(t - 1) at the previous moment, record the deviation deltP(t - 1) between the high pressure ph at the previous sampling moment and the set upper limit, Calculate the deviation deltP(t) between the high pressure ph at the current moment and the set upper limit, Calculate the deviation coefficient at the current moment: b(t) = Kp(1 + deltTao / 2 / Ti), Calculate the deviation coefficient at the previous moment: b(t - 1) = Kp(deltTao / 2 / Ti - 1), Calculate the compressor speed: n(t) = n(t - 1) + deltN; If it is not 0.2 ≤ deltP < 0.5, then determine whether it is the lower limit speed. If it is the lower limit speed, maintain the lower limit speed; if it is not the lower limit speed, record the total compressor speed n(t - 1) at the previous moment, record the deviation deltP(t - 1) between the high pressure ph at the previous sampling moment and the set upper limit, Calculate the deviation deltP(t) between the high pressure ph at the current moment and the set upper limit, Calculate the deviation coefficient at the current moment: b(t) = Kp(1 + deltTao / 2 / Ti), Calculate the deviation coefficient at the previous moment: b(t - 1) = Kp(deltTao / 2 / Ti - 1), Calculate the compressor speed: n(t) = n(t - 1) + deltN; kp is the proportional gain, Ti is the integral time, and deltTao is the sampling period.
[0036] As Figure 10 shown, during heating, the opening control module of the bypass electronic expansion valve (the first electronic expansion valve 7): Collect the suction pressure pl, the discharge pressure ph, the suction temperature tx, and the discharge temperature tp; Record the opening M(t - 1) at the previous moment; Calculate the deviation difference deltP(t) of the current high-pressure exhaust pressure ph and the set value phs; Calculate the suction saturation temperature te according to the suction pressure pl, which is calculated according to the refrigerant property table Calculate the suction superheat degree deltTsh; deltTsh=tx-te; Calculate the deviation of the suction superheat degree and the set value deltTshs: E_tsh(t)=deltTsh-deltTshs; Calculate the electronic expansion valve opening degree increment: DeltM1=kp(E_tsh(t)-E_tsh(t-1)), Calculate the electronic expansion valve opening degree 1: M1(t)=M(t-1)+deltM; Calculate the deviation difference deltP(t) of the current high-pressure exhaust pressure ph and the set value phs Calculate the electronic expansion valve opening degree increment: deltM2=kp(deltP(t)-deltP(t-1)), Calculate the electronic expansion valve opening degree 2: M2(t)=M(t-1)+deltM2, Calculate the electronic expansion valve opening degree Mt=a*M1(t)+(1-a)M2(t); Where kp is the proportional gain, and a is the weight coefficient.
[0037] The second electronic expansion valve 8 opening degree control module includes: Collect the suction pressure pl, the exhaust pressure ph, the suction temperature tx, and the exhaust temperature tp; Input the current compressor speed n(t), record the opening degree M(t-1) and the speed n(t-1) at the last time; Calculate the superheat degree deviation correction value E_x: E_x=(n(t)-n(t-1)) / n(t-1) / 0.003 / (kp+kp*deltTtao / Ti); Calculate the suction saturation temperature te according to the suction pressure pl (according to the refrigerant property table) Calculate the suction superheat degree deltTsh: deltTsh=tx-te; Calculate the deviation of the suction superheat degree and the set value deltTshs: E_tsh=deltTsh-deltTshs; Calculate the corrected suction superheat deviation: E(t) = E_tsh + E_x; Calculate the current time superheat deviation correction coefficient c(t): c(t) = kp + kp * deltTao / 2 / Ti; Calculate the last time superheat deviation correction coefficient c(t-1): c(t-1) = -kp + kp * deltTao / 2 / Ti; Calculate the electronic expansion valve opening increment: DeltM = c(t) * E(t) + c(t-1) * E(t-1); Calculate the electronic expansion valve opening: M(t) = M(t-1) + DeltM; Determine whether the electronic expansion valve M(t) is out of limit; If it is out of limit, M(t) takes the limit value; If it is not out of limit, output M(t); Where kp is the proportional gain, Ti is the integral time, and deltTao is the sampling period.
[0038] The heat pump system is used to recover the waste heat of the automobile battery and motor, and a one-to-two refrigeration system is used to simultaneously cool the air in the vehicle and the battery water system. The heat pump operation energy consumption in winter and excessive seasons is reduced, and the appropriate battery temperature is maintained, thereby improving the cruising range; The application adopts reasonable control logic to realize stable operation of the heat pump air conditioning system. When the heat pump is running, the compressor frequency is varied, the indoor evaporator is bypassed, and the outdoor condenser is used for auxiliary heat dissipation to adjust the system high pressure.
[0039] The heat pump system of the application takes heat from the intermediate medium water through the plate heat exchanger, which can ensure the efficient and stable operation of the heat pump system in low temperature environment. The heat source uses water system heat storage to solve the problem of insufficient heat pump operation performance and small heating capacity in extremely low temperature winter; The application integrates the indoor condenser, indoor evaporator and PTC auxiliary heater in the air conditioning box, realizes the functions of refrigeration, heating and defrosting in the vehicle through one air conditioning box, and saves the use space in the vehicle.
[0040] The above only describes the preferred embodiments of the application. It should be noted that those skilled in the art can make some changes and improvements without departing from the overall concept of the application, and these should be considered as the protection scope of the application.
Claims
1. A control method for a dual-split heat pump air conditioning system, characterized in that: The heat pump air conditioning system includes a compressor (1), a refrigeration solenoid valve (2), a heating solenoid valve (3), an external condenser (4), a first check valve (5), a second check valve (6), a first electronic expansion valve (7), a second electronic expansion valve (8), a plate heat exchanger (9), an air conditioning unit (10), and a gas-liquid separator (11). The air conditioning unit (10) integrates an in-vehicle condenser, an in-vehicle evaporator, a PTC auxiliary heater, and a blower. The exhaust port of the compressor (1) is divided into two paths. One path is connected to the external condenser (4) via the refrigeration solenoid valve (2), and the other end of the external condenser (4) is connected to the first check valve (5). The other path is connected to the air conditioning unit via the heating solenoid valve (3). (10) The in-vehicle condenser is connected at one end to the second one-way valve (6); the other ends of the first one-way valve (5) and the second one-way valve (6) are respectively connected to one end of the first electronic expansion valve (7) and the second electronic expansion valve (8), the other end of the first electronic expansion valve (7) is connected to the in-vehicle evaporator in the air conditioning unit (10), the other end of the in-vehicle evaporator is connected to the inlet of the gas-liquid separator; the other end of the second electronic expansion valve (8) is connected to the plate heat exchanger, the other end of the plate heat exchanger is connected to the inlet of the gas-liquid separator (11), the outlet of the gas-liquid separator (11) is connected to the suction port of the compressor (1); the plate heat exchanger is also connected to the automotive water system circuit; The control method includes a refrigeration cycle operation method and a heating cycle operation method; The refrigeration cycle operation method includes: The vehicle interior temperature ta is collected by a temperature sensor installed inside the vehicle, and the water temperature tw is collected by a temperature sensor installed in the vehicle's water system circuit. Determine if the vehicle interior temperature ta is greater than the set value; If the temperature inside the vehicle ta is not greater than the set value, the battery cooling is turned on separately, the first electronic expansion valve (7) is closed, the second electronic expansion valve (8) is opened, the cooling solenoid valve (2) is opened, the heating solenoid valve (3) is closed, the compressor (1) is opened, and the system cooling capacity control module adjusts the compressor speed and the opening degree of the second electronic expansion valve (8). If the interior temperature ta is greater than the set value, then determine whether the water temperature tw is greater than the set value. If the water temperature tw is greater than the set value, the air conditioner and the battery will cool at the same time, the first electronic expansion valve (7) and the second electronic expansion valve (8) will open at the same time, the cooling solenoid valve (2) will open, the heating solenoid valve (3) will close, the compressor (1) will open, and the system cooling capacity control module will adjust the compressor speed and the opening degree of the first electronic expansion valve (7) and the second electronic expansion valve (8). If the water temperature tw is not greater than the set value, the air conditioner will be turned on for cooling only. The first electronic expansion valve (7) will be opened, the second electronic expansion valve (8) will be closed, the cooling solenoid valve (2) will be opened, the heating solenoid valve (3) will be closed, the compressor (1) will be turned on, and the system cooling capacity control module will adjust the compressor speed and the opening degree of the first electronic expansion valve (7). The heating cycle operation method includes: Collect the vehicle interior temperature ta and the water temperature tw; Determine if the interior temperature ta is greater than the set value; if not, determine if the coolant temperature tw is less than the set value. If the water temperature tw is less than the set value, the liquid thermal PTC in the car's water system circuit will turn on; If the water temperature tw is not less than the set value, the first electronic expansion valve (7) is closed, the second electronic expansion valve (8) is opened, the refrigeration solenoid valve (2) is closed, the heating solenoid valve (3) is opened, and the system heat control module adjusts the compressor speed and the opening degree of the electronic expansion valve.
2. The control method according to claim 4, characterized in that: The control method of the system cooling capacity control module includes the following steps: A1: By using temperature and pressure sensors respectively installed at the compressor intake and exhaust ports, the following data are collected: intake pressure pl, exhaust pressure ph, intake temperature tx, exhaust temperature tp, compressor speed n, and electronic expansion valve opening k; the electronic expansion valve includes a first electronic expansion valve (7) and a second electronic expansion valve (8). A2: Are both air conditioning and battery cooling turned on simultaneously? A3: If both cooling systems are operating simultaneously, calculate the suction superheat of the plate heat exchanger (twsh) and the suction superheat deviation (deltTwsh). A4: Based on the superheat deviation deltTwsh of the plate heat exchanger, a PI controller is used to control the opening of the second electronic expansion valve (8), and the superheat deviation correction value e is used to compensate and control the valve opening. A5: If both are in cooling mode, calculate the air conditioner suction superheat (tash). Calculate the air conditioner intake superheat deviation deltTash; A6: Based on the superheat deviation of the air conditioner intake deltTash, a PI controller is used to control the opening of the first electronic expansion valve (7), and the superheat deviation correction value e is used to compensate and control the valve opening. A7: Calculate the deviation between the water temperature tw and the set temperature deltTw; A8: Calculate the deviation between the interior temperature ta and the set temperature deltTa; A9: Calculate the compressor speed n using the PID algorithm based on deltTw and deltTa; Based on deltTa, the compressor speed n is calculated using a PID algorithm; A10: Determine if the exhaust pressure (ph) is less than the set value. A11: If the exhaust pressure ph is not less than the set value; adjust the compressor speed n using a proportional-integral algorithm based on the difference between ph and the high pressure set value phs; calculate the electronic expansion valve superheat deviation correction value e using a proportional algorithm based on the compressor speed n, and then return to steps A4 and A6 respectively. A12: If the exhaust pressure ph is less than the set value; calculate the electronic expansion valve superheat deviation correction value e according to the compressor speed n using a proportional algorithm, and then return to steps A4 and A6 respectively; A13: If the cooling is not on simultaneously; only the air conditioner is on for cooling, then proceed with steps A8-A12; A14: If the cooling is not on simultaneously, but only the battery is on, then calculate the deviation between the water temperature tw and the set temperature deltTw. Based on deltTw, the compressor speed n is calculated using the PID algorithm, and then steps A10-A12 are performed.
3. The control method according to claim 2, characterized in that: The compressor speed adjustment in cooling mode includes: Collect intake pressure pl, exhaust pressure ph, intake temperature tx, exhaust temperature tp, vehicle interior temperature ta, and water temperature tw; B: If the exhaust pressure Ph is greater than the set value and the cooling is done by a single battery, record the compressor speed n2(t-1) at the previous moment, and record the water temperature tw and the deviation from the set temperature deltTw(t-1) and deltTw(t-2) at the previous two sampling moments respectively. Calculate the deviation between the current water temperature tw and the set temperature tws, deltTw(t); Calculate the deviation coefficient at the current time: a(t) = Kp(1 + deltTao / 2 / Ti + Td / deltTao); Calculate the deviation coefficients for the first two time points respectively: a(t-1)=Kp(deltTao / 2 / Ti-2Td / deltTao-1); a(t-2)=Kp*Td / deltTao Calculate the compressor speed increment: deltN2=a(t)*deltTa(t)+a(t-1)*deltTa(t-1)+a(t-2)*deltTa(t-2); Calculate the compressor speed: n2(t) = n2(t-1) + deltN2; C: If the exhaust pressure Ph is greater than the set value and the air conditioning is on for cooling only, record the compressor speed n1(t-1) at the previous moment, and record the temperature difference between the vehicle interior ta and the set temperature deltTa(t-1) and deltTa(t-2) at the previous two sampling moments respectively. Calculate the deviation between the current in-vehicle temperature ta and the set temperature tas, deltTa(t); Calculate the deviation coefficient at the current time: a(t)=Kp(1+deltTao / 2 / Ti+Td / deltTao); Calculate the deviation coefficients for the first two time points respectively: a(t-1)=Kp(deltTao / 2 / Ti-2Td / deltTao-1); a(t-2) = Kp * Td / deltTao; Calculate the compressor speed increment: deltN1=a(t)*deltTa(t)+a(t-1)*deltTa(t-1)+a(t-2)*deltTa(t-2); Calculate the compressor speed: n1(t) = n1(t-1) + deltN1; D: If the exhaust pressure Ph is greater than the set value, and both battery cooling and air conditioning are on simultaneously, Then calculate the current total compressor speed: n(t) = n1(t) + n2(t); E: If the exhaust pressure Ph is not greater than the set value: Record the total compressor speed n(t-1) at the previous time, and record the deviation between the high-pressure exhaust pressure ph and the set upper limit deltP(t-1) at the previous sampling time; Calculate the deviation between the current high-pressure exhaust pressure ph and the set upper limit deltP(t); Calculate the deviation coefficient at the current time: b(t) = Kp(1 + deltTao / 2 / Ti); Calculate the deviation coefficient at the previous time step: b(t-1) = Kp(deltTao / 2 / Ti-1); Calculate the compressor speed increment: deltN= b(t) * deltP(t) + b(t-1)* deltP(t-1); Calculate the compressor speed: n(t) = n(t-1) + deltN; Where Kp is the proportional gain, Ti is the integral time, Td is the derivative time, and deltTao is the sampling period.
4. The control method according to claim 2, characterized in that: The electronic expansion valve opening adjustment module includes: Collect inhalation pressure pl, exhaust pressure ph, inhalation temperature tx, and exhaust temperature tp; Input the current compressor speed n(t), and record the opening degree M(t-1) and speed n(t-1) at the previous time. Calculate the superheat deviation correction value E_x: E_x=(n(t)-n(t-1)) / n(t-1) / 0.003 / (kp+kp*deltTtao / Ti); Calculate the suction saturation temperature te based on the suction pressure pl (look up the table based on the refrigerant properties). Calculate the intake superheat deltTsh: deltTsh=tx-te; Calculate the deviation between the intake superheat and the setpoint deltTshs: E_tsh = deltTsh - deltTshs; Calculate the corrected intake superheat deviation: E(t) = E_tsh + E_x; Calculate the superheat deviation correction factor c(t) at the current moment: c(t) = kp + kp * deltTao / 2 / Ti; Calculate the superheat deviation correction factor c(t-1) at time step: c(t-1) = -kp + kp * deltTao / 2 / Ti; Calculate the opening increment of the electronic expansion valve: DeltM=c(t)*E(t)+c(t-1)*E(t-1); Calculate the opening degree of the electronic expansion valve: M(t) = M(t-1) + DeltM; Determine whether the electronic expansion valve M(t) is out of limit; If the limit is exceeded, then M(t) takes the limit value; If the limit is not exceeded, output M(t); Where kp is the proportional gain, Ti is the integration time, and deltTao is the sampling period.
5. The control method according to claim 1, characterized in that: The control method of the system's heating capacity control module includes: Collect suction pressure pl, discharge pressure ph, suction temperature tx, discharge temperature tp, compressor speed n, electronic expansion valve opening k, and outlet air temperature tout; Calculate the deviation between the interior temperature ta and the set temperature deltTa; Calculate the deviation deltP between the current high-pressure exhaust pressure ph and the set exhaust pressure phs; Calculate the deviation between the outlet air temperature tout and the setpoint tsout, deltTso; F: If deltTso≥0, deltP<0, then Calculate the intake superheat of the board (twsh). Calculate the superheat deviation of the intake air exchanger on the calculation board: deltTwsh; The compressor speed n is calculated using the PID algorithm based on deltTa. The superheat deviation correction value e of the second electronic expansion valve (8) is calculated using a proportional algorithm based on n; According to deltTwsh, the opening degree of the second electronic expansion valve (8) is controlled by a PI controller, and the valve opening degree is compensated and controlled by the superheat deviation correction value e. If deltTso≥0, deltP≥0, and 0MPa≤deltP≤0.2MPa, then Open the first electronic expansion valve (7) to bypass refrigerant to the vehicle evaporator; The opening degree of the first electronic expansion valve (7) is controlled by a proportional weighted algorithm based on the superheat of the indoor evaporator and deltP, and a maximum opening degree limit is set. If deltTso≥0, deltP≥0, and 0.2 Mpa < deltP ≤ 0.5 Mpa, then open the refrigeration solenoid valve (2) to dissipate heat through the external condenser. If deltTso≥0, deltP≥0, deltP ≤ 0.2 Mpa or 0.5 Mpa < deltP, adjust the compressor speed n using a proportional-integral algorithm based on the effective deltP.
6. The control method according to claim 5, characterized in that: The compressor speed adjustment in the heat pump mode includes: Collect the suction pressure pl, discharge pressure ph, suction temperature tx, discharge temperature tp, interior temperature ta, and water temperature tw. Calculate the deviation deltP between the current high-pressure discharge pressure ph and the set value phs. If deltP ≤ 0, then Record the compressor speed n1(t - 1) at the previous moment, and separately record the deviations deltTa(t - 1) and deltTa(t - 2) between the interior temperature ta and the set temperature at the previous two sampling moments. Calculate the deviation deltTa(t) between the interior temperature ta and the set temperature tas at the current moment. Calculate the deviation coefficients at the previous two moments respectively: a(t - 1) = Kp(deltTao / 2 / Ti - 2Td / deltTao - 1), a(t - 2) = Kp * Td / deltTao; Calculate the compressor speed increment: deltN1 = a(t) * deltTa(t) + a(t - 1) * deltTa(t - 1) + a(t - 2) * deltTa(t - 2); Calculate the compressor speed: n1(t) = n1(t - 1) + deltN1; If deltP ≥ 0 and 0 < deltP < 0.2, maintain the speed at the previous moment. If deltP ≥ 0 and 0.2 ≤ deltP < 0.5, then Record the total compressor speed n(t - 1) at the previous moment, and record the deviation deltP(t - 1) between the high pressure ph and the set upper limit at the previous sampling moment. Calculate the deviation deltP(t) between the high pressure ph and the set upper limit at the current moment. Calculate the deviation coefficient at the current moment: b(t) = Kp(1 + deltTao / 2 / Ti), Calculate the deviation coefficient at the previous moment: b(t - 1) = Kp(deltTao / 2 / Ti - 1), Calculate the compressor speed: n(t) = n(t - 1) + deltN; If it is not 0.2 ≤ deltP < 0.5, then determine whether it is the lower limit speed. If it is the lower limit speed, maintain the lower limit speed; if it is not the lower limit speed, record the total compressor speed n(t - 1) at the previous moment, and record the deviation deltP(t - 1) between the high pressure ph and the set upper limit at the previous sampling moment. Calculate the deviation deltP(t) between the high pressure ph and the set upper limit at the current moment. Calculate the deviation coefficient at the current moment: b(t) = Kp(1 + deltTao / 2 / Ti), Calculate the deviation coefficient at the previous moment: b(t - 1) = Kp(deltTao / 2 / Ti - 1), Calculate the compressor speed: n(t) = n(t - 1) + deltN.
7. The control method according to claim 5, characterized in that: The opening control module of the bypass electronic expansion valve during heating: Collect inhalation pressure pl, exhaust pressure ph, inhalation temperature tx, and exhaust temperature tp; Record the opening degree M(t-1) at time step 1; Calculate the deviation between the current high-pressure exhaust pressure ph and the set value phs, deltP(t); The suction saturation temperature te is calculated based on the suction pressure pl. This suction saturation temperature is determined by referring to a table based on the refrigerant properties. Calculate the intake superheat deltTsh; deltTsh=tx-te; Calculate the deviation between the intake superheat and the setpoint deltTshs: E_tsh(t) = deltTsh - deltTshs; Calculate the opening increment of the electronic expansion valve: DeltM1=kp(E_tsh(t)-E_tsh(t-1)), Calculate the opening degree of the electronic expansion valve 1: M1(t) = M(t-1) + deltM; Calculate the deviation between the current high-pressure exhaust pressure ph and the set value phs, deltP(t). Calculate the opening increment of the electronic expansion valve: deltM2=kp(deltP(t)-deltP(t-1)), Calculate the opening degree of the electronic expansion valve 2: M2(t) = M(t-1) + deltM2, Calculate the opening degree of the electronic expansion valve Mt = a*M1(t) + (1-a)M2(t); Where kp is the proportional gain and a is the weighting coefficient.
8. The control method according to claim 5, characterized in that: The second electronic expansion valve (8) opening control module during heating includes: Collect inhalation pressure pl, exhaust pressure ph, inhalation temperature tx, and exhaust temperature tp; Input the current compressor speed n(t), and record the opening degree M(t-1) and speed n(t-1) at the previous time. Calculate the superheat deviation correction value E_x: E_x=(n(t)-n(t-1)) / n(t-1) / 0.003 / (kp+kp*deltTtao / Ti); The suction saturation temperature te is calculated based on the suction pressure pl. The suction saturation temperature te is obtained by looking up refrigerant properties in a table. Calculate the intake superheat deltTsh: deltTsh=tx-te; Calculate the deviation between the intake superheat and the setpoint deltTshs: E_tsh = deltTsh - deltTshs; Calculate the corrected intake superheat deviation: E(t) = E_tsh + E_x; Calculate the superheat deviation correction factor c(t) at the current moment: c(t) = kp + kp * deltTao / 2 / Ti; Calculate the superheat deviation correction factor c(t-1) at time step: c(t-1) = -kp + kp * deltTao / 2 / Ti; Calculate the opening increment of the electronic expansion valve: DeltM=c(t)*E(t)+c(t-1)*E(t-1); Calculate the opening degree of the electronic expansion valve: M(t) = M(t-1) + DeltM; Determine whether the electronic expansion valve M(t) is out of limit; If the limit is exceeded, then M(t) takes the limit value; If the limit is not exceeded, output M(t); Where kp is the proportional gain, Ti is the integration time, and deltTao is the sampling period.