A kind of diesel engine for automobile cogeneration control system and controlling method
Technical field
The invention belongs to the heat recovery technology field, relate to a kind of diesel engine for automobile cogeneration control system and controlling method utilized.This system adopts the mode of the low temperature organic Rankine circulation loop coupling of the high temperature organic Rankine circulation loop of band close-loop feedback control and band close-loop feedback control, the thermodynamic cycle working state of regulating high-temperature circuit and low-temperature circuit respectively by the closed loop control system of design.
Background technique
The heat energy that the fuel combustion of current diesel engine for automobile produces has only about about 1/3rd to be utilized, as useful work output, also have the convection current and the heat loss through radiation of exhaust, cooling system and the engine body of nearly 2/3rds the launched machine of heat energy to consume in vain.If this energy of partly wasting can be utilized effectively, can improve the overall thermal efficiency of motor fuel on the one hand, save energy-output ratio, on the other hand, to the heat radiation of environment, improve environmental quality in the time of can reducing the diesel engine acting, slow down the trend of global warming.
Utilize the method for the discarded waste heat of diesel engine to mainly contain at present: to utilize the waste heat heating, utilize the thermo-electric generation of high exhaust temperatures, utilize the adsorption type heat pump refrigeration of waste heat and utilize the organic Rankine circulating generation or the output useful work of waste heat.Utilize the waste heat heating can utilize the waste heat of motor preferably in the winter time, but when do not need to warm oneself other season, can't make full use of the waste heat of diesel engine.Utilize the thermo-electric generation technology to be subjected to the low restriction of conversion efficiency, also can't realize the application of practicability at present.Often volume is too big to utilize the adsorption type heat pump refrigeration plant, and efficient is not high, also is not suitable for diesel engine for automobile and uses.Utilizing organic Rankine circuit heat recovery technology is the highest in current efficient, adopt organic rankine cycle system at present also in conceptual phase, current pattern does not consider that all diesel engine for automobile work working conditions change scope is wide, the characteristics of longer duration, can realize the maximum using of diesel residual heat at some operating points, but then be difficult to accomplish at other operating point.
Summary of the invention
The objective of the invention is to propose a kind of diesel engine for automobile cogeneration control system and controlling method.At diesel engine for automobile work operating mode instability, change big characteristics, the high temperature organic Rankine circulation of employing evaporating pressure close-loop feedback control and evaporating pressure, condensing temperature be the low temperature organic Rankine circulation of close-loop feedback control respectively, under the various operating modes of motor, can both realize the maximum using of diesel engine for automobile waste heat under various operating modes.
In order to realize above-mentioned target, the present invention adopts following technical solution:
The waste heat that utilizes the high temperature organic Rankine circulation of evaporating pressure close-loop feedback control that the waste gas of diesel engine is taken away is converted to useful work output, drive generator for electricity generation, utilize evaporating pressure, condensing temperature respectively the low temperature organic Rankine circulation of close-loop feedback control waste heat that the cooling liquid of diesel engine is taken away be converted to useful work output, drive generator for electricity generation, circulation of high temperature organic Rankine and low temperature organic Rankine cycle through the high temperature condenser and intercouple.
A kind of diesel engine for automobile cogeneration control system of the present invention comprises high-temperature circuit, low-temperature circuit and control access.The parts that the above-mentioned high-temperature circuit that is used to reclaim the diesel exhaust waste heat comprises have: the pipeline that high-temperature circuit working medium pump, high-temperature circuit pressure regulator valve, high-temperature circuit are regulated motor, high-temperature circuit vaporizer, high-temperature circuit decompressor, high-temperature circuit generator, high-temperature circuit evaporating pressure sensor, high-temperature circuit condenser, high-temperature circuit liquid container and connected them.The parts that the above-mentioned low-temperature circuit that is used to reclaim the Diesel Engine Coolants waste heat comprises have: the low-temperature circuit working medium pump, the low-temperature circuit pressure regulator valve, low-temperature circuit is regulated motor, the high-temperature circuit condenser, the low-temperature circuit vaporizer, the low-temperature circuit superheater, the low-temperature circuit decompressor, the low-temperature circuit generator, low-temperature circuit evaporating pressure sensor, the low-temperature circuit condenser, the low-temperature circuit condenser fan, low-temperature circuit condenser fan control motor, low-temperature circuit condensing temperature sensor, low-temperature circuit liquid container and the pipeline that connects them.The parts that the above-mentioned control access that is used to control high-temperature circuit and low-temperature circuit operation comprises have: control unit, engine rotation speed sensor, accelerator pedal position sensor, atmosphere environment temperature transducer, switch starter, high-temperature circuit evaporating pressure sensor, low-temperature circuit evaporating pressure sensor, low-temperature circuit condensing temperature sensor, high-temperature circuit are regulated the wire harness that motor, low-temperature circuit are regulated motor, low-temperature circuit condenser fan control motor and be connected these parts.
The annexation of each parts of high temperature organic Rankine circulation loop is: the high-temperature circuit working medium pump, the high-temperature circuit vaporizer, the high-temperature circuit decompressor, high-temperature circuit condenser and high-temperature circuit liquid container, they join end to end successively and form high temperature organic Rankine working medium circulation loop, high-temperature circuit adjusting motor links to each other with the high-temperature circuit working medium pump and drives its running, control the flow of working medium by regulating motor speed, the high-temperature circuit pressure regulator valve is in parallel with the high-temperature circuit working medium pump, in order to limit high evaporation pressure, high-temperature circuit decompressor output shaft links to each other with high-temperature circuit generator input shaft, drive generator for electricity generation, high-temperature circuit evaporating pressure sensor is installed on the pipeline of high-temperature circuit decompressor inlet side.
The annexation of each parts of low temperature organic Rankine circulation loop is: the low-temperature circuit working medium pump, the high-temperature circuit condenser, the low-temperature circuit vaporizer, the low-temperature circuit superheater, the low-temperature circuit decompressor, low-temperature circuit condenser and low-temperature circuit liquid container join end to end successively and form low temperature organic Rankine working medium circulation loop, the high-temperature circuit condenser is at this preheater as low-temperature circuit working medium, low-temperature circuit adjusting motor links to each other with the low-temperature circuit working medium pump and drives its running, control the flow of working medium by regulating motor speed, the low-temperature circuit pressure regulator valve is in parallel with the low-temperature circuit working medium pump, in order to limit high evaporation pressure, the output shaft of low-temperature circuit decompressor links to each other with the input shaft of low-temperature circuit generator, drive generator for electricity generation, low-temperature circuit evaporating pressure sensor is installed on the pipeline of low-temperature circuit decompressor inlet side, the low-temperature circuit condenser fan is installed in the dead ahead of low-temperature circuit condenser, by the low-temperature circuit condenser fan control motor driving coaxial with it, regulate the low-temperature circuit condenser fan speed by the control motor speed, thereby control flows is crossed the cool air flow of condenser, regulates the low-temperature circuit condensing temperature with this.
The annexation that is used to control each parts of control access of high-temperature circuit and low-temperature circuit operation is: switch starter, engine rotation speed sensor, accelerator pedal position sensor, atmosphere environment temperature transducer, high-temperature circuit evaporating pressure sensor, low-temperature circuit evaporating pressure sensor, low-temperature circuit condensing temperature sensor, high-temperature circuit regulate that motor, low-temperature circuit are regulated motor, low-temperature circuit condenser fan control motor links to each other by wire harness with control unit respectively.
Control unit in the above-mentioned control access contains power circuit, master singlechip circuit, simulated measurement input circuit, digital quantity input circlult, reset circuit, clock circuit, motor-drive circuit and communicating circuit.Simulated measurement input circuit carries out signal condition to the analog amount of accelerator pedal position sensor, high-temperature circuit evaporating pressure sensor, low-temperature circuit evaporating pressure sensor, low-temperature circuit condensing temperature sensor and the output of atmosphere environment temperature transducer; The digital quantity input circlult carries out signal condition to the digital quantity of engine rotation speed sensor and switch starter output; The analog acquisition port of the single-chip microcomputer in the output terminal of simulated measurement input circuit and the master singlechip circuit is connected; The digital input/output port of the single-chip microcomputer in digital quantity input circlult output terminal and the master singlechip circuit is connected; The input end of described drive circuit links to each other with the PWM output terminal of master singlechip circuit, and the program in the single-chip microcomputer is handled and calculated according to the signal of input, gives drive circuit from the PWM port output control signal of single-chip microcomputer; The output terminal of drive circuit is regulated motor with high-temperature circuit respectively, low-temperature circuit is regulated motor and is connected with low-temperature circuit condenser fan control motor; The CAN interface of the single-chip microcomputer in communicating circuit one end and the master singlechip circuit links to each other, and the other end links to each other with the CAN bus communication port of computer or other ECU (Electrical Control Unit), realize with the monitoring communication of computer and with the data communication facility of other ECU (Electrical Control Unit).
A kind of diesel engine for automobile cogeneration controlling method, comprise: the signal of gathering high-temperature circuit evaporating pressure sensor (27), compare with the predefined target high-temperature circuit of program evaporating pressure, utilize segmentation PI controller to calculate and drive the pwm signal value that high-temperature circuit is regulated motor (12), export to high-temperature circuit and regulate the motor-drive circuit of motor (12), the calculation of parameter of segmentation PI controller; The signal of programmed acquisition engine rotation speed sensor (26) and accelerator pedal position sensor (25) as input parameter, is looked into scaling factor Kp and integral coefficient Ki that 2 dimension MAP figure obtain PI control with them respectively;
The signal of the programmed acquisition low-temperature circuit evaporating pressure sensor (24) in the control unit, compare with the predefined target low of program loop evaporating pressure, utilize segmentation PI controller to calculate and drive the pwm signal value that low-temperature circuit is regulated motor (21), export to low-temperature circuit and regulate the motor-drive circuit of motor (21), the parameter calculation procedure of segmentation PI controller is as follows: the signal of programmed acquisition engine rotation speed sensor (26) and accelerator pedal position sensor (25), as input parameter, look into scaling factor Kp and integral coefficient Ki that 2 dimension MAP figure obtain PI control with them respectively;
Programmed acquisition atmosphere environment temperature transducer (30) signal in the control unit is an input parameter, judge low-temperature circuit target condensing temperature, and with the actual low-temperature circuit condensing temperature of gathering from low-temperature circuit condensing temperature sensor (31) relatively, adopt the PI controller to calculate the pwm signal value that drives low-temperature circuit condenser fan control motor (18), the motor-drive circuit of control motor (18).
The present invention compared with prior art has the following advantages and beneficial effect:
1. adopt the mode of circulation of high temperature organic Rankine and low temperature organic Rankine circulation coupling, the heat that exhaust energy of discharging in the time of making full use of diesel engine work and cooling liquid are taken away is exported the useful work height than the single organic Rankine circuit mode at diesel exhaust gas.
2. when working at diesel engine for automobile, the different thermodynamic states of exhaust and cooling liquid, select organic working medium R245fa as high temperature organic Rankine circuit working medium, select organic working medium R134a as low temperature organic Rankine circuit working medium, compare with other working medium, they have good Security, and are little to environment damage, can realize high useful work output under the major part work operating mode of diesel engine for automobile work.
3. when working at diesel engine for automobile, the characteristics that the working conditions change scope is big, control system adopts closed loop controls to regulate circulation of high temperature organic Rankine and low temperature organic Rankine circuit working state according to the different operating modes of motor, is implemented in making full use of of diesel residual heat under the instantaneous conditions.
4. owing to utilize cogeneration, improve the useful work output of diesel engine, under same power output situation, the consumption rate of having saved fuel oil.
5. reduce the heat dissipating capacity of diesel engine, the influence that slows down greenhouse effect to atmosphere environment.Reduce the diesel engine vent gas temperature, improve the travelling comfort of urban environment.
The present invention can be applicable to various diesels engine for automobile, especially powerful diesel engine for automobile.
Description of drawings
Fig. 1 is a cogeneration control system connection diagram of the present invention.
Fig. 2 is the hardware configuration sketch of ECU (Electrical Control Unit).
Fig. 3 is a high-temperature circuit controlling method schematic diagram.
Fig. 4 regulates the motor control method schematic diagram for low-temperature circuit.
Fig. 5 is low-temperature circuit condenser fan control motor control method schematic diagram.
Fig. 6 is the program overview flow chart.
Among the figure: the 1-gas compressor; The 2-diesel engine cylinder block; The 3-exhaust driven gas turbine; 4-high-temperature circuit vaporizer; 5-low-temperature circuit superheater; The 6-baffler; 7-high-temperature circuit decompressor; 8-high-temperature circuit generator; 9-high-temperature circuit condenser; 10-high-temperature circuit liquid container; 11-high-temperature circuit working medium pump; The 12-high-temperature circuit is regulated motor; 13-high-temperature circuit pressure regulator valve; 14-low-temperature circuit decompressor; 15-low-temperature circuit generator; 16-low-temperature circuit condenser; 17-low-temperature circuit condenser fan; 18-low-temperature circuit condenser fan control motor; 19-low-temperature circuit liquid container; 20-low-temperature circuit working medium pump; The 21-low-temperature circuit is regulated motor; 22-low-temperature circuit pressure regulator valve; 23-low-temperature circuit vaporizer; 24-low-temperature circuit evaporating pressure sensor; The 25-accelerator pedal position sensor; The 26-engine rotation speed sensor; 27-high-temperature circuit evaporating pressure sensor; The 28-control unit; The 29-switch starter; 30-atmosphere environment temperature transducer; 31-low-temperature circuit condensing temperature sensor.
Embodiment
The present invention is described in further detail below in conjunction with accompanying drawing.
A kind of diesel engine for automobile cogeneration control system of the present invention, its connection diagram comprises high-temperature circuit as shown in Figure 1, low-temperature circuit and control access.The parts that the above-mentioned high-temperature circuit that is used to reclaim the diesel exhaust waste heat comprises have: the pipeline that high-temperature circuit working medium pump 11, high-temperature circuit pressure regulator valve 13, high-temperature circuit are regulated motor 12, high-temperature circuit vaporizer 4, high-temperature circuit decompressor 7, high-temperature circuit generator 8, high-temperature circuit evaporating pressure sensor 27, high-temperature circuit condenser 9, high-temperature circuit liquid container 10 and connected them.The parts that the above-mentioned low-temperature circuit that is used to reclaim the Diesel Engine Coolants waste heat comprises have: low-temperature circuit working medium pump 20, low-temperature circuit pressure regulator valve 22, low-temperature circuit is regulated motor 21, high-temperature circuit condenser 9, low-temperature circuit vaporizer 23, low-temperature circuit superheater 5, low-temperature circuit decompressor 14, low-temperature circuit generator 15, low-temperature circuit evaporating pressure sensor 24, low-temperature circuit condenser 16, low-temperature circuit condenser fan 17, low-temperature circuit condenser fan control motor 18, low-temperature circuit condensing temperature sensor 31, low-temperature circuit liquid container 19 and the pipeline that connects them.The parts that the above-mentioned control access that is used to control high-temperature circuit and low-temperature circuit operation comprises have: control unit 28, engine rotation speed sensor 26, accelerator pedal position sensor 25, switch starter 29, atmosphere environment temperature transducer 30, high-temperature circuit evaporating pressure sensor 27, low-temperature circuit evaporating pressure sensor 24, low-temperature circuit condensing temperature sensor 31, high-temperature circuit is regulated motor 12, low-temperature circuit is regulated motor 21, low-temperature circuit condenser fan control motor 18 and the wire harness that connects these parts.
The annexation of each parts is in above-mentioned a kind of diesel engine for automobile cogeneration control system:
The annexation of each parts of high temperature organic Rankine circulation loop is: high-temperature circuit working medium pump 11, high-temperature circuit vaporizer 4, high-temperature circuit decompressor 7, high-temperature circuit condenser 9 and high-temperature circuit liquid container 10, they join end to end successively and form high temperature organic Rankine working medium circulation loop, high-temperature circuit adjusting motor 12 links to each other with high-temperature circuit working medium pump 11 and drives its running, high-temperature circuit pressure regulator valve 13 is in parallel with high-temperature circuit working medium pump 11, high-temperature circuit decompressor 7 output shafts link to each other with high-temperature circuit generator 8 input shafts, and high-temperature circuit evaporating pressure sensor 27 is installed on the pipeline of high-temperature circuit decompressor 7 inlet sides.
The annexation of each parts of low temperature organic Rankine circulation loop is: low-temperature circuit working medium pump 20, high-temperature circuit condenser 9, low-temperature circuit vaporizer 23, low-temperature circuit superheater 5, low-temperature circuit decompressor 14, low-temperature circuit condenser 16 and low-temperature circuit liquid container 19 join end to end successively and form low temperature organic Rankine circulation loop, low-temperature circuit adjusting motor 21 links to each other with low-temperature circuit working medium pump 20 and drives its running, low-temperature circuit pressure regulator valve 22 is in parallel with low-temperature circuit working medium pump 20, the output shaft of low-temperature circuit decompressor 14 links to each other with the input shaft of low-temperature circuit generator 15, low-temperature circuit evaporating pressure sensor 24 is installed on the pipeline of low-temperature circuit decompressor 14 inlet sides, low-temperature circuit condenser fan 17 is installed in the dead ahead of low-temperature circuit condenser 16, is driven by the low-temperature circuit condenser fan control motor 18 coaxial with it.
The annexation that is used to control each parts of control access of high-temperature circuit and low-temperature circuit operation is: switch starter 29, engine rotation speed sensor 26, accelerator pedal position sensor 25, atmosphere environment temperature transducer 30, high-temperature circuit evaporating pressure sensor 27, low-temperature circuit evaporating pressure sensor 24, low-temperature circuit condensing temperature sensor 31, high-temperature circuit is regulated motor 12, low-temperature circuit is regulated motor 21, low-temperature circuit condenser fan control motor 18 links to each other by wire harness with control unit 28 respectively.
The structure of the control access of above-mentioned a kind of diesel engine for automobile cogeneration control system connects sketch as shown in Figure 2.Contain power circuit, master singlechip circuit, simulated measurement input circuit, digital quantity input circlult, reset circuit, clock circuit, motor-drive circuit and communicating circuit in the control unit.Simulated measurement input circuit carries out signal condition to the analog amount of accelerator pedal position sensor 25, high-temperature circuit evaporating pressure sensor 27, low-temperature circuit evaporating pressure sensor 24, low-temperature circuit condensing temperature sensor 31 and 30 outputs of atmosphere environment temperature transducer; The digital quantity input circlult carries out signal condition to the digital quantity of engine rotation speed sensor 26 and switch starter 30 outputs; The analog acquisition port of the single-chip microcomputer in the output terminal of simulated measurement input circuit and the master singlechip circuit is connected; The digital input/output port of the single-chip microcomputer in digital quantity input circlult output terminal and the master singlechip circuit is connected; The input end of described drive circuit links to each other with the output terminal of master singlechip circuit, and the program in the single-chip microcomputer is handled and calculated according to the signal of input, gives drive circuit from the pulse duration modulation port output control signal of single-chip microcomputer; The output terminal of drive circuit is regulated motor 12 with high-temperature circuit respectively, low-temperature circuit is regulated motor 21 and is connected with low-temperature circuit condenser fan control motor 18; The CAN interface of the single-chip microcomputer in communicating circuit one end and the master singlechip circuit links to each other, and the other end links to each other with the CAN bus communication port of computer or other ECU (Electrical Control Unit), realize with the monitoring communication of computer and with the data communication facility of other ECU (Electrical Control Unit).
The working medium of above-mentioned high temperature organic Rankine circulation loop is R245fa, and the working medium that is used for low temperature organic Rankine circulation loop is R134a.
Working principle of the present invention is as follows:
When diesel engine for automobile begins ignition start, switch starter 29 is connected, control unit 28 powers on and starts working, be stored in the programmed acquisition accelerator pedal position sensor 25 in the control unit 28 in advance, engine rotation speed sensor 26, atmosphere environment temperature transducer 29, high-temperature circuit evaporating pressure sensor 27, the signal of low-temperature circuit evaporating pressure sensor 24 and low-temperature circuit condenser condenses temperature transducer 31, adopt close-loop feedback control to calculate output drive signal respectively, the control high-temperature circuit is regulated motor 12, low-temperature circuit is regulated the rotating speed of motor 21 and low-temperature circuit condenser fan control motor 18.
Above-mentioned high-temperature circuit close-loop feedback control principle as shown in Figure 3, the signal of the programmed acquisition high-temperature circuit evaporating pressure sensor 27 in the control unit 28, compare with the optimal objective high-temperature circuit evaporating pressure of selecting by calculating in advance, utilize segmentation PI controller to calculate and drive the drive signal value that high-temperature circuit is regulated motor 12, export to the high-temperature circuit motor-drive circuit subsequently.Because when diesel engine for automobile is operated in different rotating speeds different load state, the high-temperature circuit working medium flow is controlled partly non-linear very big, so adopt segmentation PI controller to select different PI controller parameters, the speed and the precision of control when improving the work of diesel engine for automobile wide variation.The scaling factor and the integral coefficient computational methods of segmentation PI controller are as follows: the signal of programmed acquisition engine rotation speed sensor 26 and accelerator pedal position sensor 25, and look into 22 dimension MAP figure respectively and obtain Kp and the Ki Control Parameter that PI controls.The calculating formula of PI controller is as follows:
PWM wherein
HwBe the drive signal that high-temperature circuit is regulated motor 12, K
P_hwBe high-temperature circuit proportional control factor, K
I_hwBe high-temperature circuit integral control coefficient, P
T_hwBe high-temperature circuit target evaporating pressure value, P
R_hwBe the actual evaporating pressure value of high-temperature circuit.
The control of low-temperature circuit evaporating pressure part principle as shown in Figure 4 in the above-mentioned low-temperature circuit close-loop feedback control principle, the signal of the programmed acquisition low-temperature circuit evaporating pressure sensor 24 in the control unit, compare with the optimal objective low-temperature circuit evaporating pressure of selecting by calculating in advance, utilize segmentation PI controller to calculate and drive the drive signal value that low-temperature circuit is regulated motor 21, export to low-temperature circuit subsequently and regulate motor 21 drive circuits.Because when diesel engine for automobile is operated in different rotating speeds different load state, the low-temperature circuit working medium flow is controlled partly non-linear very big, so adopt segmentation PI controller to select different PI controller parameters, the speed and the precision of control when improving the work of diesel engine for automobile wide variation.The parameter calculation procedure of segmentation PI controller is as follows: the signal of programmed acquisition engine rotation speed sensor 26 and accelerator pedal position sensor 25, and look into 22 dimension MAP figure respectively and obtain Kp and the Ki Control Parameter that PI controls.The calculating formula of PI controller is as follows:
PWM wherein
LwBe the drive signal that low-temperature circuit is regulated motor 12, K
P_lwBe low-temperature circuit proportional control factor, K
I_lwBe low-temperature circuit integral control coefficient, P
T_lwBe low-temperature circuit target evaporating pressure value, P
R_lwBe the actual evaporating pressure value of low-temperature circuit.
The control of low-temperature circuit condensing temperature part principle as shown in Figure 5 in the above-mentioned low-temperature circuit close-loop feedback control principle, programmed acquisition atmosphere environment temperature transducer 30 signals in the control unit, look into 1 dimension table and judge low-temperature circuit target condensing temperature, this target condensing temperature is according to different atmosphere environment temperature conditions, preestablish and be stored in the program by calculating as the form of 1 dimension table, the signal value of the target condensing temperature of calculating and the actual low-temperature circuit condensing temperature sensor 31 of collection relatively, adopt the PI controller to calculate and drive the control signal value that the low-temperature circuit condenser fan is controlled motor 18, export to low-temperature circuit condenser fan control motor 18 drive circuits subsequently.
Working procedure of the present invention is as follows:
When diesel engine for automobile began ignition start, switch starter 29 was connected, and control unit 28 powers on, and control program is started working, and the flow chart of main program as shown in Figure 6.At first, control program carries out initialization operation, sets the value of relevant register, and relevant Control Parameter is called among the RAM.Subsequently, control program is opened interrupt operation, and opening with 4 milliseconds is the major cycle control program in cycle.The major cycle control program judges whether 4 milliseconds of time cycles arrive afterwards, if do not have, continues to wait for, if arrive, then enters the collecting sensor signal module.The collecting sensor signal module is gathered the signal of accelerator pedal position sensor 25, engine rotation speed sensor 26, atmosphere environment temperature transducer 30, high-temperature circuit evaporating pressure sensor 27, low-temperature circuit evaporating pressure sensor 24 and low-temperature circuit condenser condenses temperature transducer 31, carry out respectively depositing among the RAM behind the digital filtering, as current real signal value.Afterwards, the major cycle control program enters the high-temperature circuit control module, according to the requirement of above-mentioned high-temperature circuit close-loop feedback control principle, calculates drive signal value, exports to the drive circuit that high-temperature circuit is regulated motor 12.Enter the low-temperature circuit control module afterwards,, calculate drive signal value, export to the drive circuit that low-temperature circuit is regulated motor 21 according to the partly requirement of principle of control of low-temperature circuit evaporating pressure in the above-mentioned low-temperature circuit close-loop feedback control principle.Then, the condenser fan control module is calculated drive signal value according to the partly requirement of principle of control of low-temperature circuit condensing temperature in the above-mentioned low-temperature circuit close-loop feedback control principle, exports to the drive circuit of low-temperature circuit condenser fan control motor 18.At last, the major cycle control program enters the CAN communication module, check the communication request whether upper-position unit takes place, if have, the CAN communication module sends relevant information according to the requirement of upper-position unit, if do not have, then finishes the control task of 4 millisecond periods this time, enter wait, up to the arrival of next 4 milliseconds of time cycles.