CN102691555B - Recovery system with heat accumulator for internal combustion engine exhausting waste heat and control method - Google Patents

Abstract

The internal combustion engine exhaust waste heat recovery system and control method with a heat accumulator, uses the heat transfer oil circuit to transfer the internal combustion engine exhaust heat to the organic working medium in the organic Rankine cycle loop, realizes the evaporation of the organic working medium, and uses the organic rankine cycle in series The heat accumulator in the circuit absorbs or releases heat from the organic working medium, and uses the expander to convert the enthalpy change in the expansion process into useful work output, adjusts the organic working medium flow rate in a small range according to the internal combustion engine speed and load, and adjusts the flow rate of the organic working medium according to the output of the heat accumulator The superheated temperature of the organic working medium realizes the closed-loop control of the working medium flow in the heat storage circuit, the closed-loop control of the heat transfer oil flow is realized by using the tail gas temperature at the outlet of the exhaust pipe as the feedback quantity, and the closed-loop control of the fan motor is realized by taking the organic working medium temperature at the condenser outlet as the feedback quantity . The waste heat recovery system can make full use of the exhaust waste heat of the internal combustion engine to ensure that the flow rate of the organic working medium does not change too much due to the large-scale change of the exhaust waste heat during the dynamic operation of the internal combustion engine, thereby ensuring that the output power of the expander does not fluctuate greatly.

Description

With exhaust heat of internal combustion engine reclaiming system and the controlling method of thermal accumulator

Technical field

The invention belongs to heat recovery technology field, relate to exhaust heat of internal combustion engine reclaiming system and controlling method with thermal accumulator.This system adopts utilizes conduction oil loop that the waste heat in I. C. engine exhaust is passed to the working medium in organic Rankine circulation loop vaporizer, utilization is connected on thermal accumulator in organic Rankine circulation loop and absorbs heat or release heat to organic working medium from organic working medium, adopt single-screw expander output useful work to drive generator generating, by the closed loop control system of design, according to the working state of internal-combustion engine, regulate respectively the thermodynamic cycle working state in conduction oil loop, organic Rankine circulation loop and accumulation of heat loop.

Background technique

The heat energy that the fuel combustion of current Vehicular internal combustion engine produces only has sub-fraction to be converted into useful work output, also has 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 the energy of this part waste can be utilized effectively, can improve on the one hand the overall thermal efficiency of motor fuel, save energy-output ratio, on the other hand, in the time of can reducing internal-combustion engine acting, to the heat radiation of environment, improve environmental quality, the trend of slowing global warming.

Utilize at present the method for the discarded waste heat of internal-combustion engine to mainly contain: to utilize 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 of waste heat or export useful work.Utilize waste heat heating can utilize preferably in the winter time the waste heat of motor, but when do not need to warm oneself other season, cannot make full use of the waste heat of internal-combustion engine.Utilize thermo-electric generation technology to be subject to the restriction that conversion efficiency is low, also cannot realize practical application at present.Often volume is too large to utilize adsorption type heat pump refrigeration plant, and efficiency is not high, is also not suitable for Vehicular internal combustion engine application.Utilizing the heat recovery technology of organic Rankine circulation is the highest in current efficiency, adopt organic rankine cycle system at present also in conceptual phase, current pattern all seldom considers that Vehicular internal combustion engine working excursion is wide, dynamic duty process duration is long, the unsettled feature of waste heat heat, at some operating points, can realize the maximum using of afterheat of IC engine, but be difficult to accomplish at other operating point.

Summary of the invention

The object of the invention is to propose exhaust heat of internal combustion engine reclaiming system and the controlling method with thermal accumulator.The large unsettled feature of exhaust heat thermal change while working for Vehicular internal combustion engine, utilize phase change heat storage material to regulate the distribution in the course of the work of exhaust heat heat, while guaranteeing in internal-combustion engine dynamic working procedure because of exhaust heat wide variation, in organic Rankine circulation loop, the variation of organic working medium flow is unlikely too large, thereby guarantee that decompressor output-power fluctuation amplitude is little, can realize the stable power stage of organic Rankine circulation loop, be conducive to extend the life-span of workpiece simultaneously.

In order to realize above-mentioned target, the present invention adopts following technical solution:

The waste heat that utilizes the conduction oil loop of delivery temperature closed-loop feedback control that I. C. engine exhaust is taken away fully passes to the organic working medium of organic Rankine circulation loop, utilize the accumulation of heat loop of superheat temperature closed-loop feedback control to regulate the release rate of waste heat in working procedure, utilize the condensing temperature waste heat that closed-loop feedback control is come conduction oil circuit transmission in conjunction with the organic Rankine circulation loop of open loop control to be respectively converted to useful work output, the generating of drive generator, conduction oil loop and organic Rankine circulation loop are coupled by vaporizer, accumulation of heat loop and organic Rankine circulation loop are coupled by thermal accumulator.

Exhaust heat of internal combustion engine reclaiming system with thermal accumulator of the present invention, comprises conduction oil loop, organic Rankine circulation loop, accumulation of heat loop and control access.Above-mentioned have for absorbing the parts that the conduction oil loop of exhaust heat of internal combustion engine comprises: conduction oil loop working medium pump, conduction oil circuit pressure modulating valve, conduction oil loop modulation motor, exhaust heat exchanger, vaporizer, exhaust normal open switch valve, exhaust normally closed switch valve and connect their pipeline.The parts that the organic Rankine circulation loop of the above-mentioned conversion of the waste heat hot merit for internal-combustion engine comprises have: organic Rankine circulation loop working medium pump, organic Rankine circulation loop pressure regulator valve, organic Rankine circulation loop regulate motor, vaporizer, thermal accumulator, single-screw expander, generator, condenser, condenser fan, condenser fan to regulate motor and connect their pipeline.The above-mentioned parts that comprise for the accumulation of heat loop of accumulation of heat have: accumulation of heat loop working medium pump, accumulation of heat loop modulation motor, accumulation of heat circuit controls valve, vaporizer, thermal accumulator and connect their pipeline.The above-mentioned parts that comprise for the control access of controlling have: control unit, engine rotation speed sensor, accelerator pedal position sensor, atmospheric temperature sensor, switch starter, exhaust exhaust gas temperature sensor, conduction oil temperature transducer, organic working medium superheat temperature sensor, organic working medium condensing temperature sensor, conduction oil loop modulation motor, organic Rankine circulation loop regulates motor, condenser fan regulates motor, accumulation of heat loop modulation motor, exhaust normal open switch valve, exhaust normally closed switch valve, accumulation of heat circuit controls valve and connect the wire harness of these parts.

The annexation of the each parts in conduction oil loop is: conduction oil loop working medium pump, exhaust heat exchanger and vaporizer are by the pipeline composition circulation loop that joins end to end successively, conduction oil loop modulation motor is connected and drives its running with conduction oil loop working medium pump, by regulating motor speed, control the flow of conduction oil, conduction oil circuit pressure modulating valve is in parallel with conduction oil loop working medium pump, in order to limit conduction oil Maximum operating pressure, exhaust heat exchanger is serially connected on the outlet pipe of turbine outlet, conduction oil temperature transducer is arranged on the pipeline of exhaust heat exchanger outlet side, on pipeline before the exhaust gas entrance of exhaust heat exchanger, be connected in series exhaust normal open switch valve, on bypass outlet pipe on pipeline before the entrance of exhaust normal open switch valve, be connected in series exhaust normally closed switch valve.

The annexation of the each parts of organic Rankine circulation loop is: organic Rankine circulation loop working medium pump, vaporizer, thermal accumulator, single-screw expander, condenser is by the pipeline composition circulation loop that joins end to end successively, organic Rankine circulation loop regulates motor be connected and drive its running with organic Rankine circulation loop working medium pump, by regulating motor speed, control the flow of organic working medium, organic Rankine circulation loop pressure regulator valve is in parallel with organic Rankine circulation loop working medium pump, in order to limit high evaporation pressure, in vaporizer, utilize the heat of conduction oil to evaporate organic working medium, in thermal accumulator, utilize phase change heat storage material to regulate waste heat thermal release speed, the output shaft of single-screw expander is connected with the input shaft of generator, the generating of drive generator, condenser fan is arranged on the dead ahead of condenser, by the condenser fan coaxial with it, regulate motor to drive, by regulating motor speed to regulate condenser fan speed, thereby control the cool air flow that flows through condenser, with this, regulate organic working medium condensing temperature.

The annexation of the each parts in accumulation of heat loop is: accumulation of heat loop working medium pump, accumulation of heat circuit controls valve, vaporizer and thermal accumulator are successively by the pipeline composition that joins end to end, accumulation of heat loop modulation motor is connected with accumulation of heat loop working medium pump and drives its running, by regulating motor speed to control the release rate of waste heat in thermal accumulator.

The annexation that is used for the each parts in control access of controlling conduction oil loop and the operation of organic Rankine circulation loop is: engine rotation speed sensor, accelerator pedal position sensor, atmospheric temperature sensor, switch starter, exhaust exhaust gas temperature sensor, conduction oil temperature transducer, organic working medium superheat temperature sensor, organic working medium condensing temperature sensor, conduction oil loop modulation motor, organic Rankine circulation loop regulates motor, condenser fan regulates motor, accumulation of heat loop modulation motor, exhaust normal open switch valve, exhaust normally closed switch valve, accumulation of heat circuit controls valve is connected by wire harness with control unit respectively, exhaust exhaust temperature installation of sensors is on the pipeline of the exhaust side outlet of exhaust heat exchanger, conduction oil temperature transducer is arranged on the pipeline of conduction oil side outlet of exhaust heat exchanger, organic working medium superheat temperature installation of sensors is on the pipeline of single-screw expander inlet side, and organic working medium condensing temperature installation of sensors is on the pipeline of condensator outlet side.

Control unit in above-mentioned control access contains power circuit, master singlechip circuit, simulated measurement input circuit, digital input circuit, reset circuit, clock circuit, motor-drive circuit, switch driving circuit and communicating circuit.Simulated measurement input circuit carries out signal condition to the analog amount of accelerator pedal position sensor, exhaust exhaust gas temperature sensor, conduction oil temperature transducer, organic working medium superheat temperature sensor, organic working medium condensing temperature sensor and the output of atmospheric temperature sensor; Digital input circuit carries out signal condition to the digital quantity of engine rotation speed sensor and switch starter output; The output terminal of simulated measurement input circuit is connected with the analog acquisition port of the single-chip microcomputer in master singlechip circuit; Digital input circuit output terminal is connected with the digital IO port of the single-chip microcomputer in master singlechip circuit; The input end of described motor-drive circuit is connected with the output terminal of master singlechip circuit, the signal of the programmed acquisition input in single-chip microcomputer, and carry out digital filtering processing, calculate the value that drives signal, from pulse duration modulation (PWM) port of single-chip microcomputer, export control signal to motor-drive circuit; The output terminal of motor-drive circuit regulates motor, condenser fan to regulate motor and accumulation of heat loop modulation motor to be connected with conduction oil loop modulation motor, organic Rankine circulation loop respectively; The input end of described switch driving circuit is connected with the output terminal of master singlechip circuit, program in single-chip microcomputer is from the digital output port output control signal of single-chip microcomputer to switch driving circuit, and the output terminal of switch driving circuit is connected with exhaust normal open switch valve, exhaust normally closed switch valve and accumulation of heat circuit controls valve respectively; Described communicating circuit one end is connected with the CAN interface of the single-chip microcomputer in master singlechip circuit, the other end is connected 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).

With the exhaust heat of internal combustion engine reclaiming system controlling method of thermal accumulator, comprise: the signal that gathers exhaust outlet exhaust gas temperature sensor, with the comparison of the predefined exhaust temperature desired value of program, utilize segmentation scales integration (PI) controller to calculate the pwm signal dutyfactor value that drives conduction oil loop modulation motor, export to the motor-drive circuit of conduction oil loop modulation motor, the parameter calculation procedure of segmentation PI controller is as follows: the signal of programmed acquisition engine rotation speed sensor and accelerator pedal position sensor, using them as input parameter, look into respectively 2 dimension MAP figure and obtain the Proportional coefficient K that PI controls _{p_oil}with integral coefficient K _{i_oil},

Gather the signal value of accelerator pedal position sensor and engine speed sensor, look into 2 dimension MAP figure and obtain driving organic Rankine circulation loop to regulate the PWM dutyfactor value of motor, export to the motor-drive circuit of organic Rankine circulation loop adjusting motor;

Gather the signal of organic working medium superheat temperature sensor, with the comparison of the predefined superheat temperature desired value of program, when actual superheat temperature lower than set desired value time, stop accumulation of heat circuit controls valve, accumulation of heat loop modulation motor and accumulation of heat loop working medium pump stop operating, utilize the heat release of the phase change heat storage material in thermal accumulator to continue heating organic working medium, to maintain organic working medium, under larger flow, still can evaporate smoothly and keep a little superheat temperature, when actual superheat temperature value is greater than the desired value of setting, accumulation of heat circuit controls valve is opened in program control, and control accumulation of heat loop modulation motor rotation, drive accumulation of heat loop working medium pump to rotate, accumulation of heat loop organic working medium utilizes phase change heat storage material to carry out accumulation of heat at circulation time, utilize segmentation PI controller to calculate the pwm signal dutyfactor value that drives accumulation of heat loop modulation motor, export to the motor-drive circuit of accumulation of heat loop modulation motor, the calculation of parameter of segmentation PI controller: the signal of programmed acquisition engine rotation speed sensor and accelerator pedal position sensor, using them as input parameter, look into respectively 2 dimension MAP figure and obtain the Proportional coefficient K that PI controls _{p_TES}with integral coefficient K _{i_TES},

Gathering atmospheric temperature sensor signal is input parameter, look into 1 dimension table and calculate organic Rankine circulation loop target condensing temperature, and with from condensing temperature sensor gather the comparison of condensing temperature actual value, using the difference of the desired value of condensing temperature and actual value as input, adopt PI controller to calculate the pwm signal dutyfactor value of driving condenser fan adjusting motor, regulate motor-drive circuit.

When normal work, program control exhaust normal open switch valve is opened, exhaust normally closed switch valve cuts out, when the sensor signal gathering occurs when abnormal, program control exhaust normal open switch valve cuts out, exhaust normally closed switch valve is opened, and closes whole afterheat generating system simultaneously, and sends alarm signal by PORT COM.

The present invention compared with prior art, has the following advantages and beneficial effect:

1. adopt thermal accumulator to regulate the releasing quantity of heat in hot merit transfer process, while guaranteeing in internal-combustion engine dynamic working procedure because of exhaust heat wide variation, in organic Rankine circulation loop, the variation of organic working medium flow is unlikely too large, thereby guarantee that decompressor output-power fluctuation amplitude is little, can realize the stable power stage of organic Rankine circulation loop, be conducive to extend the life-span of workpiece simultaneously.

2. utilize conduction oil as the medium conducting heat, exhaust heat is passed to organic working medium, improve on the one hand the thermal conductivity of exhaust heat exchanger and vaporizer, reduced their heat exchange area and volume, saved system cost.

3. the different thermodynamic states of exhaust and cooling liquid while working according to Vehicular internal combustion engine, have selected operating temperature range at the synthetic conduction oil of-25～315 ℃ 55, adopted the working medium of organic working medium R245fa as organic Rankine circulation loop simultaneously, adopt Magnesium dichloride hexahydrate as phase change heat storage material, compared with other material, they have good Security, destruction to environment is little, can realize high useful work output under most working of Vehicular internal combustion engine work.

4. while working for Vehicular internal combustion engine, the feature that working conditions change scope is large, control system adopts closed loop controls to regulate the working state of conduction oil loop and organic Rankine circulation loop according to the different operating modes of motor, realizes making full use of of afterheat of IC engine under instantaneous conditions; Owing to utilizing cogeneration, improve the useful work output of internal-combustion engine, in same power stage situation, the consumption rate of having saved fuel oil.

5. reduce the heat dissipating capacity of internal-combustion engine to atmosphere environment, slow down the impact of greenhouse effect.Reduce exhaust gases of internal combustion engines temperature, improve the travelling comfort of urban environment.

The present invention can be applicable to various Vehicular internal combustion engines, especially powerful diesel engine for automobile.

Accompanying drawing explanation

Fig. 1 is afterheat generating system connection diagram of the present invention.

Fig. 2 is the hardware configuration sketch of ECU (Electrical Control Unit).

Fig. 3 is conduction oil circuit controls Method And Principle figure.

Fig. 4 is that organic Rankine circulation loop regulates motor control method schematic diagram.

Fig. 5 is accumulation of heat loop modulation motor control method schematic diagram.

Fig. 6 is that condenser fan regulates motor control method schematic diagram.

Fig. 7 is error protection controlling method schematic diagram

In figure: 1-gas compressor; 2-internal combustion engine cylinders; 3-exhaust driven gas turbine; 4-exhaust heat exchanger; 5-exhaust normal open switch valve; 6-exhaust normally closed switch valve; 7-exhaust gas temperature sensor; 8-vaporizer; 9-conduction oil loop modulation motor; 10-conduction oil circuit pressure modulating valve; 11-conduction oil loop working medium pump; 12-conduction oil temperature transducer; 13-thermal accumulator; 14-condenser; 15-condenser fan; 16-condenser fan regulates motor; 17-organic working medium condensing temperature sensor; 18-organic Rankine circulation loop working medium pump; 19-organic Rankine circulation loop regulates motor; 20-organic Rankine circulation loop pressure regulator valve; 21-accumulation of heat circuit controls valve; 22-accumulation of heat loop modulation motor; 23-accumulation of heat loop working medium pump; 24-organic working medium superheat temperature sensor; 25-single-screw expander; 26-generator; 27-accelerator pedal position sensor; 28-control unit; 29-switch starter; 30-atmospheric temperature sensor; 31-engine rotation speed sensor.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

Exhaust heat of internal combustion engine reclaiming system with thermal accumulator of the present invention, its connection diagram as shown in Figure 1, comprises conduction oil loop, organic Rankine circulation loop, accumulation of heat loop and control access.Above-mentioned have for absorbing the parts that the conduction oil loop of exhaust heat of internal combustion engine comprises: working medium pump 11, regulate motor 9, pressure regulator valve 10, exhaust heat exchanger 4, vaporizer 8, exhaust normal open switch valve 5, exhaust normally closed switch valve 6 and connect their pipeline.The parts that the organic Rankine circulation loop of the above-mentioned conversion of the waste heat hot merit for internal-combustion engine comprises have: working medium pump 18, adjusting motor 19, pressure regulator valve 20, vaporizer 8, thermal accumulator 13, single-screw expander 25, generator 26, condenser 14, condenser fan 15, condenser fan regulate motor 16 and connect their pipeline.The above-mentioned parts that comprise for the accumulation of heat loop of accumulation of heat have: working medium pump 23, regulate motor 22, accumulation of heat circuit controls valve 21, vaporizer 8, thermal accumulator 13 and connect their pipeline.The above-mentioned parts that comprise for the control access of controlling have: control unit 28, engine rotation speed sensor 31, accelerator pedal position sensor 27, switch starter 29, atmospheric temperature sensor 30, exhaust outlet exhaust gas temperature sensor 7, conduction oil temperature transducer 12, organic working medium condensing temperature sensor 17, organic working medium superheat temperature sensor 24, exhaust normal open switch valve 5, exhaust normally closed switch valve 6, accumulation of heat circuit controls valve 21, conduction oil loop modulation motor 9, organic Rankine circulation loop regulates motor 19, condenser fan regulates motor 16, accumulation of heat loop modulation motor 22 and connect the wire harness of these parts.

In the above-mentioned exhaust heat of internal combustion engine reclaiming system with thermal accumulator, the annexation of each parts is:

The annexation of the each parts in conduction oil loop is: working medium pump 11, and exhaust heat exchanger 4, vaporizer 8 is successively by the pipeline composition that joins end to end; Regulate motor 9 be connected with working medium pump 11 and drive its running, pressure regulator valve 10 is in parallel with working medium pump 11, exhaust heat exchanger 4 is serially connected on the outlet pipe that turbine 3 exports, the shell fluid of exhaust heat exchanger 4 is high-temp waste gas, pipe side liquid is conduction oil, conduction oil temperature transducer 12 is arranged on the pipeline of exhaust heat exchanger 4 outlet sides, on pipeline before the exhaust gas entrance of exhaust heat exchanger 4, be connected in series exhaust normal open switch valve 5, on the bypass outlet pipe on the pipeline before the entrance of exhaust normal open switch valve 5, be connected in series exhaust normally closed switch valve 6.

The annexation of the each parts of organic Rankine circulation loop is: working medium pump 18, and vaporizer 8, thermal accumulator 13, single-screw expander 25, condenser 14 is successively by the pipeline composition that joins end to end; Regulate motor 19 be connected with working medium pump 18 and drive its running, pressure regulator valve 20 is in parallel with working medium pump 18, the output shaft of single-screw expander 25 is connected with the input shaft of generator 26, organic working medium superheat temperature sensor 24 is arranged on the pipeline of single-screw expander 25 inlet sides, condenser fan 15 is arranged on the dead ahead of condenser 14, by the condenser fan coaxial with it, regulate motor 16 to drive, condensing temperature sensor 17 is arranged on the pipeline of condenser 14 outlet sides.

The annexation of the each parts in accumulation of heat loop is: working medium pump 23, accumulation of heat circuit controls valve 21, vaporizer 8 and thermal accumulator 13 are successively by the pipeline composition that joins end to end, and accumulation of heat loop modulation motor 22 is connected with working medium pump 23 and drives its running.

The annexation that is used for the each parts in control access of controlling conduction oil loop and the operation of organic Rankine circulation loop is: switch starter 29, engine rotation speed sensor 31, accelerator pedal position sensor 27, atmospheric temperature sensor 30, exhaust outlet exhaust gas temperature sensor 7, conduction oil temperature transducer 12, organic working medium condensing temperature sensor 17, organic working medium superheat temperature sensor 24, exhaust normal open switch valve 5, exhaust normally closed switch valve 6, accumulation of heat circuit controls valve 21, conduction oil loop modulation motor 9, organic Rankine circulation loop regulates motor 18, condenser fan regulates motor 16, accumulation of heat loop modulation motor 22 is connected by wire harness with control unit 28 respectively.

The structure of the control access of the above-mentioned exhaust heat of internal combustion engine reclaiming system with thermal accumulator connects sketch as shown in Figure 2.In control unit, contain power circuit, master singlechip circuit, simulated measurement input circuit, digital input circuit, reset circuit, clock circuit, motor-drive circuit, switch driving circuit and communicating circuit.The analog amount that simulated measurement input circuit is exported accelerator pedal position sensor 27, exhaust exhaust gas temperature sensor 7, conduction oil temperature transducer 12, organic working medium superheat temperature sensor 24, organic working medium condensing temperature sensor 17 and atmospheric temperature sensor 30 is carried out signal condition; The digital quantity that digital input circuit is exported engine rotation speed sensor 31 and switch starter 29 carries out signal condition; The output terminal of simulated measurement input circuit is connected with the analog acquisition port of the single-chip microcomputer in master singlechip circuit; Digital input circuit output terminal is connected with the digital IO port of the single-chip microcomputer in master singlechip circuit; The input end of described motor-drive circuit is connected with the output terminal of master singlechip circuit, the signal of the programmed acquisition input in single-chip microcomputer, and carry out digital filtering processing, calculate the value that drives signal, from pulse duration modulation (PWM) port of single-chip microcomputer, export control signal to motor-drive circuit; The output terminal of motor-drive circuit regulates motor 19, condenser fan to regulate motor 16 and accumulation of heat loop modulation motor 22 to be connected with conduction oil loop modulation motor 9, organic Rankine circulation loop respectively; The input end of described switch driving circuit is connected with the output terminal of master singlechip circuit, program in single-chip microcomputer is from the digital output port output control signal of single-chip microcomputer to switch driving circuit, and the output terminal of switch driving circuit is connected with exhaust normal open switch valve 5, exhaust normally closed switch valve 6 and accumulation of heat circuit controls valve 21 respectively;

Described communicating circuit one end is connected with the CAN interface of the single-chip microcomputer in master singlechip circuit, the other end is connected 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 in above-mentioned conduction oil loop is

55, the phase change heat storage material in thermal accumulator adopts MgCl ₂6H ₂o is R245fa for the working medium of organic Rankine circulation loop.

Working principle of the present invention is as follows:

When Vehicular internal combustion engine starts ignition start, switch starter 29 is connected, control unit 28 powers on and starts working, pre-stored programmed acquisition accelerator pedal position sensor 27 in control unit 28, engine rotation speed sensor 31, atmospheric temperature sensor 30, exhaust exhaust gas temperature sensor 7, conduction oil temperature transducer 12, the signal of organic working medium superheat temperature sensor 24 and organic working medium condensing temperature sensor 17, adopt respectively closed-loop feedback control to calculate output drive signal, control conduction oil loop modulation motor 9, accumulation of heat loop modulation motor 22 and condenser fan regulate the rotating speed of motor 16, adopt open loop control to calculate the drive signal value of driving organic Rankine circulation loop adjusting motor 19, when the sensor signal that detects when program is normal, keep exhaust normal open switch valve 5 to open, exhaust normally closed switch valve 6 cuts out, and when program detects that the signal of sensor occurs when abnormal, closing exhaust normal open switch valve 5, opens exhaust normally closed switch valve 6.

Above-mentioned conduction oil circuit controls Method And Principle as shown in Figure 3, the signal of the programmed acquisition exhaust outlet place exhaust gas temperature sensor 7 in control unit 28, with in advance by calculating selected exhaust temperature optimal objective value comparison, utilize segmentation PI controller to calculate the drive signal value of driving conduction oil loop modulation motor 9, export to subsequently conduction oil loop modulation motor-drive circuit.PI controller comprises ratio governing loop and integral adjustment link.What ratio regulated act as the deviation of reaction system in proportion, once there is deviation in system, ratio regulates and produces immediately regulating action in order to reduce deviation, proportional action is large, can accelerate to regulate, reduce error, but excessive ratio, make the stability decreases of system, even cause the unstable of system.Acting as of integral adjustment makes system eliminate steady-state error, improves without margin, if there is error, integral adjustment just carries out, until indifference, integral adjustment just stops.While being operated in different rotating speeds different load state due to Vehicular internal combustion engine, conduction oil loop working medium flow control part non-linear very large, so adopt segmentation PI controller to select different PI controller parameters, speed and the precision controlled while improving the work of Vehicular internal combustion engine wide variation.Scaling factor and the integral coefficient computational methods of segmentation PI controller are as follows: the signal of programmed acquisition engine rotation speed sensor 31 and accelerator pedal position sensor 27, and look into respectively 22 dimension MAP figure and obtain the K that PI controls _{p_oil}and K _{i_oil}control parameter.The calculating formula of PI controller is as follows:

${\mathrm{PWM}}_{\mathrm{oil}}=K_{p\_\mathrm{oil}}{(T_{\mathrm{exh}\_t}-T_{\mathrm{exh}\_r})}_n+K_{i\_\mathrm{oil}}\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{(T_{\mathrm{exh}\_t}-T_{\mathrm{exh}\_r})}_k$

Wherein PWM _oilfor the PWM of conduction oil loop modulation motor 9 drives signal dutyfactor value, K _{p_oil}for the scaling factor of conduction oil loop PI controller, K _{i_oil}for the integral coefficient of conduction oil loop PI controller, T _{exh_t}for the desired value of exhaust exhaust temperature, T _{exh_r}for the actual value of exhaust exhaust temperature, subscript n represents the numerical value of current time, and k represents the numerical value in all moment.

Above-mentioned organic Rankine circulation loop regulates motor control method principle as shown in Figure 4, programmed acquisition engine rotation speed sensor 31 in control unit 28 and the signal of accelerator pedal position sensor 27, look into the PWM dutyfactor value that 2 dimension MAP figure obtain driving signal, export to the motor-drive circuit of organic Rankine circulation loop adjusting motor 19.

Above-mentioned accumulation of heat loop modulation motor control method principle as shown in Figure 5, the signal of the programmed acquisition organic working medium superheat temperature sensor 24 in control unit 28, with the comparison of the predefined superheat temperature desired value of program, when actual superheat temperature lower than set desired value time, stop accumulation of heat circuit controls valve 21, accumulation of heat loop modulation motor 22 and accumulation of heat loop working medium pump 23 stop operating, utilize the heat release of the phase change heat storage material in thermal accumulator 13 to continue heating organic working medium, to maintain organic working medium, under larger flow, still can evaporate smoothly and keep a little superheat temperature, when actual superheat temperature value is greater than the desired value of setting, accumulation of heat circuit controls valve 21 is opened in program control, and control accumulation of heat loop modulation motor 22 and turn round, drive accumulation of heat loop working medium pump 23 to rotate, accumulation of heat loop organic working medium utilizes phase change heat storage material to carry out accumulation of heat at circulation time, utilize segmentation PI controller to calculate the pwm signal dutyfactor value that drives accumulation of heat loop modulation motor, export to the motor-drive circuit of accumulation of heat loop modulation motor 22, the calculation of parameter of segmentation PI controller: the signal of programmed acquisition engine rotation speed sensor 31 and accelerator pedal position sensor 27, using them as input parameter, look into respectively 2 dimension MAP figure and obtain the Proportional coefficient K that PI controls _{p_TES}with integral coefficient K _{i_TES},

${\mathrm{PWM}}_{\mathrm{TES}}=K_{p\_\mathrm{TES}}{(T_{\sup \_t}-T_{\sup \_r})}_n+K_{i\_\mathrm{TES}}\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{(T_{\sup \_t}-T_{\sup \_R})}_k$

Wherein PWM _tESfor regulating the PWM of motor 19, organic Rankine circulation loop drives signal dutyfactor value, K _{p_TES}for the scaling factor of organic Rankine circulation loop PI controller, K _{i_TES}for the integral coefficient of organic Rankine circulation loop PI controller, T _{sup_t}for the desired value of organic working medium superheat temperature, T _{sup_r}for the actual value of organic working medium superheat temperature, subscript n represents the numerical value of current time, and k represents the numerical value in all moment.

Above-mentioned condenser fan regulates motor control method principle as shown in Figure 6, programmed acquisition atmospheric temperature sensor 30 signals in control unit 28, look into the desired value that 1 dimension table judges organic working medium condensing temperature, this target condensing temperature is according to different atmospheric temperature conditions, by calculating, preset and be stored in program as the form of 1 dimension table, the signal value comparison of the target condensing temperature of calculating and the actual organic working medium condensing temperature sensor 17 of collection, using the difference of the desired value of condensing temperature and actual value as input, adopt PI controller to calculate the control signal value of driving condenser fan adjusting motor 16, export to subsequently the drive circuit that condenser fan regulates motor 16.

Above-mentioned error protection controlling method principle as shown in Figure 7, program in control unit 28 detects the signal value of exhaust exhaust gas temperature sensor 7, organic working medium superheat temperature sensor 24, organic working medium condensing temperature sensor 17 and conduction oil temperature transducer 12, when their value of detection is all in normal range (NR), assert that system works is normal, program control exhaust normal open switch valve 5 is opened, and exhaust normally closed switch valve 6 cuts out; When detect with the value of upper sensor have at least one be greater than the maximum value of setting or lower than set minimum value time, decision-making system work occurs abnormal, program control exhaust normal open switch valve 5 in control unit 28 cuts out, exhaust normally closed switch valve 6 is opened, close whole afterheat generating system simultaneously, and send alarm signal by PORT COM.

Working procedure of the present invention is as follows:

When Vehicular internal combustion engine starts ignition start, switch starter 29 is connected, and control unit 28 powers on, and control program is started working.First, control program carries out initialization operation, sets the value about register, and relevant control parameter is called in RAM.Subsequently, control program is opened interrupt operation, opens take 10 milliseconds of major cycle control programs as the cycle.Major cycle control program judges whether 10 milliseconds of time cycles arrive afterwards, if do not had, continues to wait for, if arrived, enters collecting sensor signal module.Collecting sensor signal module gathers the signal of accelerator pedal position sensor 27, engine rotation speed sensor 31, atmospheric temperature sensor 30, exhaust exhaust gas temperature sensor 7, organic working medium superheat temperature sensor 24, organic working medium condensing temperature sensor 17 and conduction oil sensor 12, carry out respectively depositing in RAM after digital filtering, as current real signal value.Afterwards, whether the signal that major cycle control program judges sensor is in normal range of operation, if normal, program is carried out normal system control program.First routine call conduction oil loop modulation motor drive module, according to the requirement of above-mentioned conduction oil circuit controls Method And Principle, calculates drive signal value, exports to the drive circuit of conduction oil loop modulation motor 9.Enter afterwards organic Rankine circulation loop and regulate motor drive module, according to above-mentioned organic Rankine circulation loop, regulate the requirement of motor control method principle, calculate drive signal value, export to the drive circuit of organic Rankine circulation loop adjusting motor 19.Then, condenser fan regulates motor drive module according to above-mentioned condenser fan, to regulate the requirement of motor control method principle, calculates drive signal value, exports to the drive circuit of condenser fan adjusting motor 16.After this, accumulation of heat loop modulation motor drive module, according to the requirement of above-mentioned accumulation of heat loop modulation motor control method principle, calculates drive signal value, exports to the motor-drive circuit of accumulation of heat loop modulation motor 22.Finally, major cycle control program enters CAN communication module, check the communication request whether upper-position unit occurs, if had, CAN communication module sends relevant information according to the requirement of upper-position unit, if do not had, finishes this time control task of 10 millisecond periods, enter wait, until the arrival of next 10 milliseconds of time cycles.If it is abnormal to detect that the signal of sensor occurs, first program opens exhaust normally closed switch valve 6, close subsequently exhaust normal open switch valve 5, and send alarm signal by CAN communication, afterwards, stop cogeneration machine, cuts out conduction oil with this and regulates motor 9, organic Rankine circulation loop to regulate motor 19, accumulation of heat loop modulation motor 22 and condenser fan to regulate motor 16, after completing above action, program stopped moves, and waits for that maintenance man overhauls.

Claims (7)

1. The internal combustion engine exhaust waste heat recovery system with heat accumulator, uses the heat transfer oil circuit to transfer the waste heat in the internal combustion engine exhaust to the organic working medium in the organic Rankine cycle circuit, and realizes the evaporation and gasification of the organic working medium. The regenerator in the organic Rankine cycle absorbs heat from the organic working fluid or releases heat to the organic working medium, and uses a single-screw expander to convert the enthalpy change during the expansion process of the high-enthalpy working medium into useful work output to drive the generator to generate electricity , using the control system to maximize the utilization of exhaust waste heat under different working conditions of the internal combustion engine; it is characterized in that: The heat transfer oil circuit includes a heat transfer oil circuit working medium pump (11), an exhaust heat exchanger (4), an evaporator (8), an exhaust normally open switch valve (5), an exhaust normally closed switch valve ( 6) and the pipelines connecting them; the heat transfer oil circuit regulating motor (9) is connected with the heat transfer oil circuit working medium pump (11) and drives its operation, the pressure regulating valve (10) is connected in parallel with the heat conducting oil circuit working medium pump (11), It is used to limit the maximum pressure difference of the heat transfer oil circuit. The exhaust heat exchanger (4) is connected in series to the exhaust pipe at the outlet of the turbine. The shell side fluid of the exhaust heat exchanger (4) is high-temperature exhaust gas, and the tube side fluid is Heat transfer oil, the heat transfer oil temperature sensor (12) is installed on the pipe on the outlet side of the exhaust heat exchanger (4), and the exhaust normally open switch valve is connected in series on the pipe before the exhaust gas inlet of the exhaust heat exchanger (4) (5), the exhaust normally closed switch valve (6) is connected in series on the bypass exhaust pipe on the pipeline before the inlet of the exhaust normally open switch valve (5); Described organic rankine cycle loop, by organic rankine cycle loop working fluid pump (18), evaporator (8), heat accumulator (13), single-screw expander (25), condenser (14) pass through successively The pipes are connected end to end; the organic Rankine cycle regulating motor (19) is connected with the organic Rankine cycle working medium pump (18) to drive its operation, and the pressure regulating valve (20) is connected with the organic Rankine cycle working medium pump (18 ) in parallel, used to limit the maximum evaporation pressure of the organic Rankine cycle, the single-screw expander (25) is connected with the generator (26) to drive it to generate electricity, and the condenser fan (15) is installed on the positive side of the condenser (14). The front is driven by a condenser fan regulating motor (16) coaxial with it; The heat storage circuit is composed of the heat storage circuit working medium pump (23), the control valve (21), the evaporator (8), and the heat accumulator (13) connected end to end through pipelines in turn, and the heat storage circuit regulates the motor (22) and the heat storage circuit. The heat circuit working medium pump (23) is connected and drives its operation. 2. The internal combustion engine exhaust waste heat recovery system with heat accumulator according to claim 1, characterized in that: said control system consists of an engine speed sensor (31), an accelerator pedal position sensor (27), a start switch ( 29), atmospheric environment temperature sensor (30), exhaust pipe outlet exhaust gas temperature sensor (7), heat transfer oil temperature sensor (12), organic working fluid condensation temperature sensor (17), organic working fluid superheat temperature sensor (24), Exhaust normally open switch valve (5), exhaust normally closed switch valve (6), heat storage circuit control valve (21), heat transfer oil circuit regulating motor (9), organic Rankine cycle circuit regulating motor (19), condensation The fan regulator motor (16) is connected to the control unit (28) through a wire harness. The heat transfer oil temperature sensor (12) is installed on the pipe at the outlet of the heat transfer oil side of the exhaust heat exchanger (4). The organic working medium superheat temperature sensor ( 24) Installed on the pipeline on the inlet side of the single-screw expander (25), and the condensation temperature sensor (17) is installed on the pipeline on the outlet side of the condenser (14). 3. The internal combustion engine exhaust waste heat recovery system with heat accumulator according to claim 2, characterized in that: the control unit includes: a power supply circuit, a main single-chip circuit, an analog input circuit, a digital input circuit, a reset circuit, clock circuit, motor drive circuit, switch drive circuit and communication circuit. 4. The internal combustion engine exhaust waste heat recovery system with heat accumulator according to claim 3, characterized in that: the analog input circuit is connected to the accelerator pedal position sensor (27), exhaust pipe outlet exhaust gas temperature sensor (7 ), the heat transfer oil temperature sensor (12), the organic working medium superheat temperature sensor (24), the organic working medium condensation temperature sensor (17) and the analog output of the atmospheric environment temperature sensor (30) carry out signal conditioning; the digital quantity input circuit The digital output of the engine speed sensor (31) and the start switch (29) is used for signal conditioning; the output end of the analog input circuit is connected to the analog acquisition port of the single-chip microcomputer in the main single-chip circuit; the output end of the digital input circuit is connected to the main single-chip microcomputer The digital input and output ports of the microcontroller are connected in the circuit. 5. The internal combustion engine exhaust waste heat recovery system with heat accumulator according to claim 3, characterized in that: the input end of the motor drive circuit is connected to the output end of the main single-chip microcomputer circuit, and the program acquisition input in the single-chip microcomputer signal, and carry out digital filtering processing, calculate the value of the driving signal, and output the control signal from the pulse width modulation (PWM) port of the single chip microcomputer to the motor driving circuit; The Rankine cycle regulating motor (19) is connected with the condenser fan regulating motor (16); The input end of the switch driving circuit is connected with the output end of the main single-chip microcomputer circuit, and the program in the single-chip microcomputer outputs control signals from the digital output port of the single-chip microcomputer to the switch driving circuit according to the working conditions, and the output ends of the switch driving circuit are respectively connected with the exhaust normal Open the on-off valve (5), the exhaust normally closed on-off valve (6) and the heat storage circuit control valve (21) to connect; One end of the communication circuit is connected to the CAN interface of the single-chip microcomputer in the main single-chip circuit, and the other end is connected to the CAN bus communication port of the computer or other electronic control units to realize monitoring communication with the computer and data communication with other electronic control units. 6. The internal combustion engine exhaust waste heat recovery system with heat accumulator according to claim 1, characterized in that: the working fluid used in the heat transfer oil circuit is high-temperature synthetic heat transfer oil Therminol55, and the heat transfer oil used in the heat accumulator (13) is The heat storage phase change heat storage material is magnesium chloride hexahydrate, and the working fluid used in the organic Rankine cycle is R245fa. 7. The control method of the internal combustion engine exhaust waste heat recovery system with a heat accumulator is characterized in that it includes: the program in the control unit (28) collects the signal of the exhaust pipe outlet exhaust gas temperature sensor (7), and the exhaust gas temperature sensor (7) set in advance by the program Comparing the temperature target value, using the segmental proportional integral controller to calculate the PWM signal duty cycle value driving the heat transfer oil circuit regulating motor (9), and outputting it to the motor drive circuit of the heat transfer oil circuit regulating motor (9), the segmental proportional integral controller The parameter calculation process is as follows: the program collects the signals of the engine speed sensor (31) and the accelerator pedal position sensor (27), and uses them as input parameters to check the 2-dimensional MAP diagram respectively to obtain the proportional coefficient K _{p_oil} and the integral coefficient K of the proportional integral control _{i_oil} ; The program in the control unit (28) collects the signal values of the accelerator pedal position sensor (27) and the internal combustion engine speed sensor (31), and checks the 2-dimensional MAP diagram to obtain the PWM signal duty cycle value for driving the organic Rankine cycle loop regulation motor (19) , output to the motor drive circuit of the organic Rankine cycle loop regulating motor (19); The program in the control unit (28) collects the signal of the organic working medium superheat temperature sensor (24), compares it with the target value of the superheat temperature set in advance by the program, and when the actual superheat temperature is lower than the set target value, the program turns off the heat storage The circuit control valve (21), the heat storage circuit regulating motor (22) and the heat storage circuit working medium pump (23) stop rotating, and the heat release of the phase change heat storage material in the heat storage (13) is used to continue heating the organic working medium , in order to maintain the smooth evaporation of the organic working medium under a large flow rate and maintain a small superheating temperature, when the actual superheating temperature value is greater than the set target value, the program control opens the regenerative circuit control valve (21), and Control the operation of the heat storage circuit regulating motor (22), drive the heat storage circuit working fluid pump (23) to rotate, the organic working medium in the heat storage circuit uses phase change heat storage materials to store heat during circulation, and uses the segmental proportional integral controller to calculate Drive the PWM signal duty cycle value of the heat storage circuit regulation motor (22), output to the motor drive circuit of the heat storage circuit regulation motor (22), and calculate the parameters of the segmental proportional integral controller: the program collects the engine speed sensor (31) and The signals of the accelerator pedal position sensor (27) are used as input parameters to check the 2-dimensional MAP diagram respectively to obtain the proportional coefficient K _{p_TES} and the integral coefficient K _{i_TES} of the proportional integral control; The program in the control unit (28) collects the signal of the ambient temperature sensor (30) as an input parameter, checks the 1-dimensional table to calculate the target condensation temperature of the organic Rankine cycle, and compares it with the actual condensation temperature collected from the condensation temperature sensor (17). Value comparison, the difference between the target value and the actual value of the condensing temperature is used as an input and the proportional-integral controller is used to calculate the PWM signal duty cycle value of the driving condenser fan regulating motor (16), and the motor driving of the condenser fan regulating motor (16) circuit; During normal operation, the program in the control unit (28) controls the exhaust normally open switch valve (5) to open, and the exhaust normally closed switch valve (6) to close. When the collected sensor signal is abnormal, the control unit (28) The program in the program controls the exhaust normally open switch valve (5) to close, the exhaust normally closed switch valve (6) to open, and at the same time close the entire waste heat power generation system, and send an alarm signal through the communication port.

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