A hybrid refrigerated truck configuration coupled with a combined cooling and power generation waste heat recovery system

Abstract

The present invention provides a hybrid refrigerated truck configuration coupled with a combined cooling and power supply type waste heat recovery system and an operating method thereof, which are applied to the field of cold chain transportation. The truck includes a hybrid drive system, a combined cooling and power supply type waste heat recovery system and a refrigerated truck body. The truck adopts a hybrid drive method to enable the engine and the electric motor to operate in a high-efficiency range, stabilize and improve the engine waste heat parameters, and promote the waste heat recovery system to more fully and effectively recover the waste heat energy from the cylinder jacket water and exhaust gas of the engine, and output the refrigerated truck required cooling capacity and electric energy. The cooling capacity output meets the cooling load of the truck air conditioning and cargo refrigeration, and can completely replace the truck air conditioning and independent refrigerators. The electric energy meets the electricity demand of the truck electrical equipment and supplements the power source under the hybrid pure electric drive mode. Comprehensively speaking, the overall efficiency and primary energy utilization rate of the truck are improved, the fuel consumption of the whole vehicle is reduced, and the purpose of energy saving and emission reduction is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of cold chain transportation, relates to a truck energy-saving system, and specifically relates to a hybrid refrigerated truck configuration coupled with a combined cooling and power supply type waste heat recovery system. Background Art

[0002] The current working efficiency of automotive internal combustion engines is generally less than 50%, resulting in a large amount of energy loss and carbon dioxide emissions. Nearly half of the energy is lost in the form of waste heat. Internal combustion engine waste heat recovery technology can effectively recycle and utilize low-grade heat sources and convert them into electrical energy. It has become a core technology for improving the primary energy utilization rate of the system and the efficiency of internal combustion engines. However, due to the constraints of the transient pulsation characteristics of the heat source of automotive internal combustion engines and the requirements of compact structure and miniaturization, there is still a large research space for the construction of automotive waste heat recovery equipment, vehicle coupling and operation optimization. The design of trucks coupled with waste heat recovery systems also needs to meet the needs of multiple energy forms.

[0003] On the one hand, the waste heat recovery system generates a large amount of electricity, and a hybrid configuration is needed to utilize the excess electricity. Therefore, it is necessary to build a hybrid configuration suitable for refrigerated trucks and waste heat recovery systems to increase efficiency. On the other hand, the refrigeration process of refrigerated trucks consumes a lot of additional energy. The cooling demand can be met by establishing a waste heat recovery system for combined cooling and power generation, eliminating the additional energy consumption for refrigeration. If the system is designed, how to establish a combined cooling and power waste heat recovery system that meets high compactness and integration is also a major problem.

[0004] In view of the above background and technical status, the present invention proposes a combined cooling and power waste heat recovery system coupled to a hybrid refrigerated truck, which can achieve efficient utilization of waste heat and coordinated management of multiple energy needs, avoid additional energy consumption for refrigeration, improve the working efficiency of the whole vehicle, reduce fuel consumption, reduce carbon dioxide emissions, and alleviate energy crisis and environmental pollution. Summary of the invention

[0005] The main purpose of the present invention is to provide a design and control scheme for a hybrid refrigerated truck configuration coupled with a combined cooling and power supply waste heat recovery system, which can fully utilize the engine waste heat to generate electricity and cooling. The electricity is used to drive the truck and power electrical equipment, and the cooling is used for cargo refrigeration and cab air conditioning. Through hybrid power, the truck and waste heat recovery system are kept running in a high-efficiency range, the waste heat parameters are stabilized, fuel is saved, and efficiency is improved. The system adopts a compact integrated design to meet the needs of miniaturization of trucks.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A hybrid refrigerated truck configuration coupled with a combined cooling and power generation waste heat recovery system comprises a hybrid drive system (2);

[0008] The hybrid drive system (2) comprises a diesel engine (18), an electric-generator motor (19), a second generator (20), an inverter (21), a power battery pack (22), a compound planetary gear set (23), a front axle (24), a rear axle (25), an engine clutch (26), an intermediate shaft driven gear (27), a main reduction gear (28), a differential gear (29), a transmission main shaft (30) and a brake device;

[0009] The brake device comprises a first brake device (31-1), a second brake device (31-2), a third brake device (31-3) and a fourth brake device (31-4);

[0010] The output of the front axle (24) is divided into two ends, the first end is connected to the first wheel, the first wheel hub is connected to the first brake device (31-1), and the other end of the front axle (24) is connected to the second wheel, the second wheel hub is connected to the second brake device (31-2);

[0011] The input end of the front axle (24) is connected to the differential gear (29), the main reduction gear (28), the intermediate shaft driven gear (27) and the compound planetary gear set (23) in sequence; one end of the compound planetary gear set (23) is connected to the electric-generator motor (19), and the other end of the compound planetary gear set (23) is connected to the second generator (20);

[0012] The input end of the second generator (20) is connected to the engine clutch (26); the engine clutch (26) is connected to the diesel engine (18);

[0013] The output end of the second generator is connected to an inverter (21); the inverter (21) is connected to a power battery pack (22);

[0014] The compound planetary gear set (23) is connected to the rear axle (25) via the transmission main shaft (30);

[0015] One end of the rear axle (25) is connected to the third wheel, and the third wheel hub is connected to the third brake device (31-3); the other end of the rear axle (25) is connected to the fourth wheel, and the fourth wheel hub is connected to the fourth brake device (31-4).

[0016] Furthermore, the second generator (20) realizes coupling and decoupling of the transmission shaft between the second generator engine (20) and the clutch (26) and the hybrid compound planetary gear set (23) through a pressure plate structure. When the state of charge (SOC) of the power battery pack (22) is lower than a set value (SOC<0.2), the pressure plate presses the transmission shaft, and the second generator (20) is coupled to the engine power system. The torque of the diesel engine (18) transmitted by the engine clutch is used as a power source to drive the second generator (20) to operate. The generated electricity is used to charge the power battery pack (22) through the inverter (21). When the SOC reaches a set upper limit (SOC>0.5), the pressure plate is released, the second generator (20) is decoupled from the engine, the second generator (20) stops running, and charging stops.

[0017] Furthermore, when the truck is running, the diesel engine (18) and the electric-generator motor (19) output torque according to the quota set by the program; the diesel engine (18) rotates, and after the engine clutch (26) adjusts the speed, the torque is transmitted to the compound planetary gear set (23), and at the same time, the electric-generator motor (19) rotates to transmit the torque to the compound planetary gear set, and the compound planetary gear set (23) adjusts and distributes the torque, and transmits the torque to the main reduction gear (28) through the intermediate shaft driven gear (27) to reduce the speed and increase the torque and drive the transmission main shaft (30) to rotate, and the transmission main shaft (30) transmits the torque to the differential gear (29) respectively to drive the front axle (24) and the rear axle (25) to make the tires roll, and the vehicle runs normally.

[0018] Furthermore, the compound planetary gear set (23) changes the mutual motion relationship by changing the fixed elements in the gear system, distributes the torque output by the diesel engine (18) and the electric-generator motor (19), changes the transmission ratio between the diesel engine (18), the electric-generator motor (19) and the transmission main shaft (30), adjusts the rotation speed of the power components or interrupts the power transmission, thereby realizing the truck hybrid drive.

[0019] Furthermore, the electric-generator motor (19) is a permanent magnet electric-generator integrated machine, and the electric-generator motor (19) includes a permanent magnet stator and a permanent magnet rotor. When the power battery pack (22) inputs a three-phase voltage to the permanent magnet stator coil of the motor, a rotating magnetic field is generated, and the permanent magnet rotor is passively rotated under the action of same-phase repulsion, presenting as an electric motor, that is, when the truck is driven by electricity, the electricity in the power battery pack (22) is converted into kinetic energy output of the truck through rotation; when the permanent magnet rotor rotates under the action of external force, current is induced in the three-phase coil of the permanent magnet stator, presenting as a generator, that is, when the truck brakes, electromagnetic damping braking is generated to recover kinetic energy and generate electricity stored in the power battery pack (22).

[0020] Furthermore, the configuration also includes a combined cooling and power waste heat recovery system (3). The combined cooling and power waste heat recovery system includes a preheater (32), a regenerator (33), a heater (34), a turbine (35), a condenser (36), a working fluid pump (37), a liquid storage tank (38), a throttle valve (39), an evaporator (40), a compressor (41), and a waste heat recovery generator (42);

[0021] The outlet of the working fluid side of the condenser (36) is connected to the inlet of the liquid storage tank (38), and the outlet of the liquid storage tank (38) is connected to the first interface of the three-way control valve (v1) of the waste heat recovery system. The second interface of the three-way control valve (v1) of the waste heat recovery system is connected in sequence to the working fluid pump (37), the preheater (32), the high temperature side of the regenerator (33), the heater (34), the turbine (35) and the inlet of the low temperature side of the regenerator (33). The outlet of the low temperature side of the regenerator (33) is connected to the condenser (36) to form a closed loop of the power sub-cycle. The main shaft of the turbine (35) is connected to the main shaft of the waste heat recovery generator (42). The third interface of the three-way control valve (v1) of the waste heat recovery system is connected in sequence to the throttle valve (39), the evaporator (40) and the inlet of the compressor (41), and the outlet of the compressor is connected to the condenser (36) to form a closed loop of the refrigeration sub-cycle. Inside the waste heat recovery system (3), the power sub-cycle and the refrigeration sub-cycle share the condenser (36) and the liquid storage tank (38).

[0022] Furthermore, the power sub-cycle refers to the cycle part that recovers waste heat to produce electricity. It adopts a transcritical cycle. The working fluid enters the power cycle from the condenser (36) through the three-way control valve (v1) of the waste heat recovery system. After being pressurized by the working fluid pump (37), it is heated to a supercritical state by the preheater (32), the regenerator (33) and the heater (34) in sequence. The resulting high-temperature and high-pressure working fluid drives the turbine (35) to do work to drive the waste heat recovery generator (42) to rotate and generate electricity. The working fluid is cooled in the regenerator (33) and then condensed by the condenser (36) to complete the power cycle.

[0023] Furthermore, the refrigeration sub-cycle refers to the part of the cycle that produces refrigeration capacity. Compression refrigeration is adopted. The working fluid enters the refrigeration cycle from the condenser (36) through the three-way control valve (v1) of the waste heat recovery system, is reduced in pressure to the two-phase region by the throttle valve (39), evaporates to a saturated gas state in the evaporator (40) and outputs cold capacity, and then is pressurized to superheat by the compressor (41), mixed with the high-temperature steam from the regenerator (33) of the power sub-cycle, and returns to the condenser (36) to complete the refrigeration sub-cycle.

[0024] Furthermore, the hybrid refrigerated truck configuration also includes an exhaust gas recirculation system (13). The exhaust gas recirculation system includes an exhaust gas cooler and an exhaust gas recirculation valve (14); the exhaust gas cooler is connected to the inlet of the exhaust gas recirculation valve (14); the outlet of the exhaust gas recirculation valve (14) is divided into two paths, one of which is connected to the diesel particulate filter (15) and the selective catalytic reduction denitration system (16) in sequence, and the other is connected to the inlet of the diesel engine cylinder after merging with the air pipeline.

[0025] Furthermore, the heater (34) in the waste heat recovery system and the exhaust gas cooler in the exhaust gas recirculation system (13) are integrated into a printed circuit heat exchanger, the cold end of the heat exchanger is the working fluid of the waste heat recovery system, and the hot end is the flue gas. The working fluid in the waste heat recovery system is heated to a supercritical state in the heat exchanger, and the flue gas is cooled to the temperature required for exhaust gas recirculation.

[0026] Furthermore, the exhaust gas flow process of the diesel engine (18) is as follows: the exhaust gas of the diesel engine (18) is discharged from the cylinder of the diesel engine (18), cooled to the temperature required for exhaust gas recirculation by the waste heat recovery heater (34), and the cooled exhaust gas is divided into two parts after passing through the exhaust gas recirculation system (13). One part of the exhaust gas passes through the exhaust gas recirculation valve (14) and is mixed with the newly inhaled air and then sent back to the cylinder of the diesel engine (18) for combustion. The other part of the exhaust gas is treated by the diesel particulate filter (15) and the selective catalytic reduction denitrification system (16) and then discharged to the environment.

[0027] Furthermore, the condenser (36) of the waste heat recovery system and the water tank radiator (11) are both placed at the front of the vehicle, and the condenser (36) of the waste heat recovery system and the water tank radiator (11) are both coupled with an electronic fan to realize air-cooled heat exchange. In order to reduce the interference of the high-temperature cylinder jacket water of the diesel engine (18) on the condenser (36), the working medium side of the truck cooling system radiator (water tank radiator) is arranged in parallel with the cylinder jacket water side of the diesel engine (18), and the high-temperature cylinder jacket water of the diesel engine (18) should be on the side of the working medium away from the fan. The water tank radiator (11) is the truck cooling system radiator.

[0028] Furthermore, the flow process of the cylinder jacket water of the diesel engine (18) is as follows: the cylinder jacket water flows out from the diesel engine (18), passes through the first thermostat three-way control valve (v2), and if the temperature is lower than the set temperature, it directly returns to the diesel engine (18), completing a small cycle; if the temperature is higher than the set temperature, it enters the waste heat recovery system preheater (32) for recovery and cooling, and then flows into the second thermostat three-way control valve (v3); if the temperature is lower than the set temperature, it directly returns to the diesel engine (18), completing a recovery cycle; if the temperature is higher than the set temperature, it flows into the water tank radiator (11) to cool to the set temperature and then returns to the diesel engine (18), completing a recovery cycle and a large cycle.

[0029] Furthermore, the hybrid refrigerated truck configuration also includes a truck electronic control unit, which monitors the truck speed, acceleration and engine speed through electronic vehicle speed and speed sensors, measures the current and voltage of the power battery pack (22) through sensors to obtain the battery charge state, and distributes the torque output of the electric-generator motor (19) and the diesel engine (18) through a compound planetary gearbox (23) based on the above data to complete the switching of five driving modes: diesel engine (18) drive, electric-generator motor (19) drive and hybrid power, brake recovery and engine power generation.

[0030] Furthermore, the truck electronic control unit monitors the cylinder jacket water temperature of the diesel engine (18) through an electronic thermostat and the exhaust gas temperature of the diesel engine (18) through a thermocouple temperature sensor at the outlet exhaust pipe of the diesel engine (18). The cylinder jacket water and exhaust gas temperatures of the diesel engine (18) are used as indicators to adjust the three-way control valve (v1) of the waste heat recovery system to control the start, stop and operation of the power and refrigeration sub-cycles of the waste heat recovery system.

[0031] Furthermore, the truck electronic control unit monitors the current temperature in the refrigerated compartment (7) through a temperature sensor in the refrigerated compartment, determines the temperature difference from the target refrigeration temperature, determines the battery charge state in combination with the current and voltage of the power battery pack (22), and adjusts the flow rate of the coolant entering the cab air conditioner (9) and the refrigerated compartment refrigeration heat exchanger (10) and the fan air supply volume through the refrigeration distribution control valve (v5) to control the refrigeration mode.

[0032] Furthermore, the truck electronic control unit monitors the cylinder jacket water temperature of the diesel engine (18) through the diesel engine (18) outlet temperature sensor to control the opening of the electronic thermostat, thereby changing the cylinder jacket water waste heat recovery and utilization and the operation strategy of the large and small cycles of the diesel engine (18) cooling system.

[0033] Furthermore, the refrigerated truck can switch the driving mode of the truck according to different driving conditions. When the power of the on-board power battery pack is higher than the set state of charge (SOC) (SOC>0.2), the electric-generator motor (19) is used for driving when starting, idling or driving at low speed (low speed means lower than the set speed, and the speed of low speed driving is generally lower than 20 km / h). When driving in normal mode (normal mode means within the set speed range, and the speed of normal mode driving is generally between 20 and 60 km / h), the diesel engine (18) is used for driving. When driving in acceleration or high speed (the high speed driving means higher than the set speed range), the diesel engine (18) is used for driving. When the truck is traveling at high speed (generally at a speed greater than 60 km / h), the hybrid drive system (2) is used to drive the truck, which is driven by the diesel engine and the electric-generator motor (19) to achieve maximum acceleration and performance; when the power of the on-board power battery pack (22) is lower than the set state of charge value (SOC<0.2), in order to ensure the normal operation of the cargo refrigeration and the truck electrical equipment, the diesel engine (18) drives the truck to travel and drives the second generator (20) to charge the power battery pack (22); when the truck decelerates and brakes, the electric-generator motor (19) can recover its braking energy and store it in the power battery pack (22) through the inverter (21).

[0034] Furthermore, the waste heat recovery refrigeration subsystem replaces the original truck air conditioner and refrigeration unit of the traditional refrigerated truck. The evaporator (40) outputs the cooling capacity required by the system. The cold end of the evaporator (40) is the working fluid of the waste heat recovery system (3), and the hot end is the refrigerant. The cooling capacity distribution is achieved by controlling the refrigerant flow entering the cab air conditioner (9) and the refrigerated compartment (7). The cooling capacity is output to the cab (6) and the refrigerated truck to achieve air cooling.

[0035] Furthermore, the hybrid refrigerated truck configuration also includes a refrigerated truck body (1); the refrigerated truck body (1) includes a refrigerated truck cab (6), a refrigerated compartment (7), a chassis (8), a cab air conditioner (9), a refrigerated compartment refrigeration heat exchanger (10), a water tank radiator (11), on-board electrical equipment (12), an exhaust gas treatment system (5) and a fuel tank (17).

[0036] Furthermore, the front part of the refrigerated truck body (1) is a refrigerated truck cab (6), the cab air conditioner (9) and on-board electrical equipment (12) are installed in the cab (6), and the water tank radiator (11) and the waste heat recovery system condenser (36) are placed in the cab; the rear part of the refrigerated truck body is a refrigerated compartment (7), and the front part of the refrigerated compartment (7) is equipped with a refrigerated compartment refrigeration heat exchanger (10), and the compartment refrigeration heat exchanger (10) completes the compartment refrigeration in the form of air cooling through a fan; the bottom of the refrigerated truck body (1) is a refrigerated truck chassis (8), and the fuel tank (17) and the power battery pack (22) are placed in the lower chassis of the refrigerated compartment (7) in the middle and rear part of the truck.

[0037] Furthermore, the exhaust gas treatment system (5) comprises an exhaust gas recirculation system (13), an exhaust gas recirculation valve (14), a diesel particulate filter (15) and a selective catalytic reduction denitration system (16). The outlet of the exhaust gas recirculation system (13) is divided into two paths, one of which is connected to the exhaust gas recirculation valve (14) and the other of which is connected to the diesel particulate filter (15) and the selective catalytic reduction denitration system (16) in sequence.

[0038] Furthermore, the hybrid drive system (2) is placed in the truck body chassis (8), the diesel engine (18) and the electric-generator motor (19) are placed in the chassis under the cab, and the first brake device (31-1), the second brake device (31-2), the third brake device (31-3) and the fourth brake device (31-4) are all placed inside the wheel hub.

[0039] Furthermore, the exhaust gas outlet of the diesel engine 18 is connected to the heater 34 and the exhaust gas recirculation system 13 in sequence, and the outlet of the exhaust gas recirculation system 13 is divided into two paths, one of which is connected to the cylinder inlet of the diesel engine 18 after merging with the supplementary air pipeline through the exhaust gas recirculation valve 14, and the other is connected to the diesel particulate filter 15 and the selective catalytic reduction denitrification system 16 in sequence.

[0040] Furthermore, the exhaust gas of the diesel engine 18 is discharged from the cylinder and cooled to the temperature required for exhaust gas recirculation by the waste heat recovery system heater 34. The cooled exhaust gas is divided into two parts after passing through the exhaust gas recirculation system 13. One part of the exhaust gas is mixed with the newly inhaled air through the EGR valve 14 and then sent into the cylinder again for combustion. The other part of the exhaust gas is processed by the diesel particulate filter 15 and the selective catalytic reduction denitrification system 16 in turn and then discharged into the environment.

[0041] The present invention proposes a hybrid refrigerated truck configuration coupled with a combined cooling and power supply waste heat recovery system, which can fully recover the medium and low-grade waste heat of the engine's cylinder jacket water and exhaust gas, generate the refrigeration required for the cab air conditioning and cargo refrigeration, and the power generation required for the truck's electrical equipment and electric drive. Its main structure is divided into three parts: the refrigerated truck body, the hybrid drive system, and the combined cooling and power supply waste heat recovery system. The refrigerated truck body is the overall frame of the truck configuration, the hybrid drive system is placed on the truck body chassis, the engine and the motor are placed under the cab, and the waste heat recovery system is placed in the cab and the chassis under the refrigerated compartment, and is highly coupled with the refrigerated truck engine, the truck-level heat exchanger, and the exhaust gas treatment device.

[0042] Hybrid refrigerated trucks achieve hybrid drive by changing the mechanical connection relationship of the compound planetary gear set, changing the transmission ratio of the engine, electric motor and main shaft, adjusting the speed of the power components, and distributing the torque output ratio of the electric-generator motor and the engine. Ultimately, the hybrid synthetic torque is transmitted to the transmission main shaft and drive axle to drive the wheels to roll. Through the above transmission system, the truck can realize the following driving modes according to the measured speed, acceleration, engine speed and state of charge (SOC) data: when the power of the on-board power battery pack is higher than the set state of charge (SOC>0.2), the electric motor is used to drive the truck when starting, idling or driving at low speed (low speed means lower than the set speed, and the speed of low speed driving is generally lower than 20km / h); when driving in normal mode (normal mode means within the set speed range, and the speed range of normal mode driving is generally between 20 and 60km / h), the engine is used to drive the truck; when driving in acceleration or high speed (high speed driving means higher than the set speed range, and the speed of high speed driving is generally greater than 60km / h), hybrid drive is used, and the engine and the electric motor are used to drive the truck together to achieve maximum acceleration and performance; when the power of the on-board power battery pack is lower than the set state of charge (SOC<0.2), in order to ensure the normal operation of cargo refrigeration and truck electrical equipment, the engine drives the truck to drive and drives the second generator to charge the battery; when the truck decelerates and brakes, the electric-generator motor can recover its braking energy and store it in the battery through the inverter.

[0043] At the same time, the waste heat recovery system determines the waste heat recovery strategy according to the cylinder jacket water temperature and exhaust temperature obtained by the engine outlet thermocouple temperature sensor. When the waste heat source meets the recovery conditions (generally the flue gas temperature is greater than 220°C and the cylinder jacket water temperature is greater than 80°C), the valve is opened, the cylinder jacket water is passed into the preheater, and the exhaust gas is passed into the heater as a heat source, and the waste heat recovery system is started. The working fluid enters the power subsystem through the three-way control valve, is pressurized by the working fluid pump, and is heated by the preheater, the regenerator and the heater respectively. It expands and does work in the turbine to drive the waste heat recovery generator (the third generator) to generate electricity, and then is cooled by the regenerator and mixed with the refrigeration sub-circulation working fluid, and is condensed by the condenser and enters the liquid storage tank to complete the cycle; the refrigeration sub-circulation working fluid is throttled and depressurized by the throttle valve through the three-way control valve, generates cooling capacity in the evaporator, and then is pressurized by the compressor, mixed with the power sub-circulation working fluid, and is condensed by the condenser and enters the liquid storage tank to complete the cycle. The power sub-cycle turbine drives the waste heat recovery generator (third generator) to generate electricity which is stored in the power battery pack through the inverter and supplies power to the vehicle electric drive, working fluid pump, compressor, fan and other power equipment. The refrigeration sub-cycle evaporator generates cold air which is transported to the cab air conditioner and refrigerated compartment refrigeration heat exchanger through the refrigerant, and then sent to the cab and refrigerated compartment through the electronic fan.

[0044] The beneficial effects of the present invention are as follows:

[0045] The hybrid system makes comprehensive use of the complementary advantages of the electric motor and the engine. When the truck is driving at low speeds, the electric motor is purely electrically driven, the motor's torque output is smooth, the acceleration response is good, and the electric motor is in an efficient working range; at medium and high speeds, the engine is driven, the engine is in a high-efficiency range, the engine efficiency is improved, and the stable waste heat is conducive to waste heat recovery, the truck's fuel consumption is greatly reduced, and exhaust emissions are reduced; during sudden acceleration, the engine is the main drive and the motor is auxiliary, which can output greater torque to meet higher driving needs; during deceleration, the electric generator motor realizes energy recovery and improves the utilization rate of primary energy; when the battery pack power is lower than the set value, the engine drives the generator to charge the battery pack to ensure stable operation of the truck hybrid.

[0046] The use of a hybrid power system is conducive to the engine's continuous operation in a high-efficiency range, so that the engine's cylinder jacket water and exhaust are stable and the flow rate remains stable, which is conducive to the efficient operation of the waste heat recovery system, avoiding frequent fluctuations and starts and stops in its operating conditions, and extending the life of the waste heat recovery system. The waste heat recovery system recycles waste heat to produce electricity, which can meet the needs of hybrid electric drive after meeting the needs of electrical equipment. The cooling output of the waste heat recovery system meets the cooling needs of the cab air conditioning and refrigerated compartments. The integration and combination of multiple system components greatly reduces system components, reduces system mass, and improves the compactness of the system. Overall, the system reduces fuel consumption and exhaust emissions, improves vehicle efficiency and primary energy utilization, and meets the needs of "carbon neutrality and carbon peak".

[0047] The hybrid refrigerated truck coupled with the combined cooling and power generation type waste heat recovery system of the present invention has a compact structure, good practicality and great energy-saving potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings shown are schematic diagrams of the implementation of the present invention:

[0049] Figure 1 A schematic diagram showing the main configuration of a hybrid refrigerated truck coupled with a combined cooling and power generation waste heat recovery system;

[0050] Figure 2 It is a schematic diagram of the overall structure and operation process of the hybrid refrigerated truck coupled with the combined cooling and power waste heat recovery system;

[0051] Figure 3 A schematic diagram of a hybrid power system and a transmission structure of a hybrid refrigerated truck coupled with a combined cooling and power generation waste heat recovery system;

[0052] Figure 4 A schematic diagram of the waste heat recovery system structure and the cold and heat source coupling form of the hybrid refrigerated truck configuration coupled with the combined cooling and power generation waste heat recovery system;

[0053] Figure 5 A schematic diagram of the configuration mode switching and control strategy of the hybrid refrigerated truck coupled with the combined cooling and power waste heat recovery system;

[0054] Among them: 1-refrigerated truck body, 2-hybrid drive system, 3-waste heat recovery system, 4-transmission system, 5-exhaust gas treatment system, 6-refrigerated truck cab, 7-refrigerated compartment, 8-chassis, 9-cab air conditioner, 10-refrigeration heat exchanger, 11-water tank radiator, 12-on-board electrical equipment, 13-exhaust gas recirculation system, 14-exhaust gas recirculation valve, 15-diesel particulate filter, 16-selective catalytic reduction denitration system, 17-fuel tank, 18-diesel engine, 19-electric-generator motor (or first generator), 20-second generator, 21-inverter, 22-power battery pack, 23-compound planetary gear set, 24-front axle (or first steering drive axle), 25-rear axle (or second drive axle), 26-engine clutch, 27-intermediate shaft driven gear, 28-main reduction gear, 29-differential gear, 30-drive main shaft, 31-1-first brake device, 31-2-second brake device, 31-3-third brake device, 31-4-fourth brake device, 32-preheater, 33-regenerator, 34-heater, 35- Turbine, 36-condenser, 37-working fluid pump, 38-liquid storage tank, 39-throttle valve, 40-evaporator, 41-compressor, 42-waste heat recovery generator (or the third generator), v1-waste heat recovery system three-way control valve, v2-first thermostat three-way control valve (small cycle), v3-second thermostat three-way control valve (large cycle), v4-turbine bypass control valve, v5-refrigeration distribution control valve. DETAILED DESCRIPTION

[0055] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. However, the following embodiments are limited to explaining the present invention, and the protection scope of the present invention should include the entire contents of the claims, and through the description of the following embodiments, those skilled in the art can fully implement the entire contents of the claims of the present invention.

[0056] Figure 1 The following is a schematic diagram of the overall layout of the hybrid refrigerated truck coupled with the combined cooling and power generation waste heat recovery system. Figure 1As shown, the main structure of the refrigerated truck configuration includes: a refrigerated truck body 1, a hybrid drive system 2 and a combined cooling and power waste heat recovery system 3. The refrigerated truck body 1 is an overall frame of the truck configuration, which is similar to the layout of a traditional refrigerated truck and includes: an exhaust gas treatment system 5, a refrigerated truck cab 6, a refrigerated compartment 7, wheels, a chassis 8, a cab air conditioner 9, a refrigerated compartment refrigeration heat exchanger 10, a water tank radiator 11, on-board electrical equipment 12, a fuel tank 17 and other truck auxiliary components, wherein the exhaust gas treatment system 5 includes an exhaust gas recirculation system 13, a diesel particulate filter 15 and a selective catalytic reduction denitration system 16.

[0057] The position relationship of the refrigerated truck body (referred to as the body) is as follows: the front of the body is the refrigerated truck cab 6, which is equipped with a cab air conditioner 9 and on-board electrical equipment 12, and the water tank radiator 11 and the waste heat recovery system condenser 36 are placed in the front of the cab. The rear of the body is the refrigerated compartment 7. The front of the refrigerated compartment 7 is equipped with a refrigeration heat exchanger 10, which uses a fan to cool the compartment in the form of air cooling. The bottom of the body is the refrigerated truck chassis 8, and the fuel tank 17 and the power battery pack 22 are placed in the lower chassis of the refrigerated compartment at the middle and rear of the truck. The hybrid drive system 2 is placed in the chassis of the truck body (see the detailed process). Figure 3 ), the diesel engine 18 and the electric-generator motor 19 are placed in the chassis under the cab, and the compound planetary gear set 23, the intermediate shaft driven gear 27 and the main reduction gear 28 connected to the transmission system 4 drive the transmission main shaft 30 to the front axle 24 (or the first steering drive axle) and the rear axle (or the second drive axle) 25 through gear meshing to make the wheels roll. The waste heat recovery system 3 is placed in the chassis 8 under the cab 6 and the refrigerated compartment 7 (see the detailed process). Figure 4 ), the outlet of the liner water pipeline of the refrigerated truck diesel engine 18 is connected to the high temperature side inlet of the waste heat recovery system preheater 32, and the high temperature side outlet of the preheater is connected to the water tank radiator 11 of the engine cooling system. The outlet of the exhaust pipeline of the engine 18 is connected to the high temperature side of the waste heat recovery heater 34, and the outlet of the heater 34 is connected to the exhaust gas recirculation system 13 of the exhaust gas treatment system 5. Among them, the compound planetary gear set 23, the intermediate shaft driven gear 27 and the main reduction gear 28 are the speed change gear set.

[0058] Figure 2 The figure is a schematic diagram of the overall structure and operation process of the hybrid refrigerated truck coupled with the combined cooling and power waste heat recovery system. Figure 2As shown, the hybrid refrigerated truck distributes the torque output of the electric-generator motor 19 and the diesel engine 18 through the hybrid compound planetary gear set 23, and transmits it to the transmission system to drive the wheels to roll. Its power end uses the power battery pack 22 as energy. When the truck is stopped, it can be charged through an external charging pile. At the same time, during operation, the electric-generator motor 19 can also recover the braking energy of the truck when braking to supplement the power. When the battery charge state is lower than the minimum set value, the diesel engine 18 can also charge the power battery pack 22 (the detailed process is shown in Figure 3 ), the waste heat recovery system 3 recovers the waste heat of the diesel engine 18 to supplement electricity (the detailed process is shown in Figure 4 The battery needs to supply the energy consumption of multiple equipment in the truck, including: the power energy consumption of the torque output of the electric-generator motor when the truck is electrically driven; the refrigeration energy consumption of the refrigeration sub-cycle of the waste heat recovery system when the waste heat source parameters are lower than the minimum parameters of the power sub-cycle of the waste heat recovery system; and the power energy consumption of 12 other on-board electrical equipment when the truck is operating normally.

[0059] The heat energy end (fuel end) uses diesel as energy. The combustion of diesel drives the cylinder to move, so that the diesel engine 18 outputs torque. At the same time, the engine cylinder water and exhaust gas take away the high-grade waste heat energy. When the cylinder water and exhaust gas temperatures reach the recovery conditions, the waste heat recovery system 3 starts to operate (the specific operation process is shown in Figure 4 ). The cylinder jacket water of the engine flows into the waste heat recovery system preheater 32 and the engine cooling system water tank radiator 11, and returns to the cylinder jacket of the diesel engine 18. After the engine exhaust flows into the waste heat recovery system heater 34, part of the exhaust gas participates in the exhaust gas recirculation, and the remaining exhaust gas is discharged from the truck after exhaust gas treatment.

[0060] The working fluid flow path of the waste heat recovery system is as follows: part of the working fluid enters the power sub-circulation through the waste heat recovery system three-way control valve v1, is pressurized by the working fluid pump 37, is heated by the preheater 32, the regenerator 33, and the heater 34 respectively, and then expands in the turbine 35 to do work, and then cools down in the regenerator 33 and mixes with the refrigeration sub-circulation working fluid; another part of the working fluid enters the refrigeration sub-circulation through the waste heat recovery system three-way control valve v1, generates cooling capacity in the evaporator 40 after passing through the throttle valve 39, and then is pressurized by the compressor 41 and mixed with the power sub-circulation working fluid; after the power and the refrigeration sub-circulation working fluid are mixed, they are condensed by the condenser 36 and enter the liquid storage tank 38 to complete the cycle. The waste heat recovery system turbine 35 drives the waste heat recovery generator (third generator) 42 to work and output electricity to be stored in the power battery pack 22, and the evaporator 40 absorbs heat and outputs cooling capacity through the refrigerant to flow into the vehicle cab air conditioner 9 heat exchanger, and the refrigerated compartment refrigeration heat exchanger 10 meets the vehicle cooling load.

[0061] In the present invention, the waste heat recovery refrigeration subsystem replaces the original truck air conditioner and refrigeration unit of the traditional refrigerated truck. The evaporator 40 outputs the cooling capacity required by the system. The cold end of the evaporator 40 is the working fluid of the waste heat recovery system 3, and the hot end is the refrigerant. The cooling capacity distribution is achieved by controlling the refrigerant flow entering the cab air conditioner 9 and the refrigerated compartment 7. The cooling capacity is output to the cab 6 and the refrigerated truck by air cooling.

[0062] Figure 3 The figure is a schematic diagram of the hybrid power system and transmission structure of the hybrid refrigerated truck coupled with the combined cooling and power generation waste heat recovery system. Figure 3 As shown, the hybrid drive system includes: a diesel engine 18, an electric-generator motor (or a first generator) 19, a second generator 20, an inverter 21, a power battery pack 22, a hybrid compound planetary gear set 23, a front axle (or a first steering drive axle) 24, a rear axle (a second drive axle) 25, an engine clutch 26, an intermediate shaft driven gear 27, a main reduction gear 28, a differential gear 29, a transmission main shaft 30 and a brake device. Among them, the compound planetary gear set 23, the intermediate shaft driven gear 27 and the main reduction gear 28 constitute a compound gear transmission of the truck.

[0063] The brake braking device includes a first brake braking device 31 - 1 , a second brake braking device 31 - 2 , a third brake braking device 31 - 3 and a fourth brake braking device 31 - 4 .

[0064] The connections of the hybrid power system for refrigerated trucks are as follows: The brake device is placed inside the wheel hub.

[0065] The output of the front axle 24 is divided into two ends, the first end is connected to the first wheel, and the first wheel hub is connected to the first brake device 31-1. The second end of the front axle 24 is connected to the second wheel. The second wheel hub is connected to the second brake device 31-2.

[0066] The front axle 24 is connected in sequence to the differential gear 29 , the main reduction gear 28 , the intermediate shaft driven gear 27 and the compound planetary gear set 23 ; one end of the compound planetary gear set 23 is connected to the electric-generator motor 19 , and the other end of the compound planetary gear set 23 is connected to the second generator 20 .

[0067] An input end of the second generator 20 is connected to an engine clutch 26 ; the engine clutch 26 is connected to the diesel engine 18 .

[0068] The output end of the second generator 20 is connected to the inverter 21 ; the inverter 21 is connected to the power battery pack 22 .

[0069] The hybrid compound planetary gear set 23 is connected to the rear axle 25 via a transmission main shaft 30 .

[0070] Optionally, the output end of the second generator is also connected to the electric motor-generator motor 19 .

[0071] The diesel engine 18 is connected to a waste heat recovery generator 42 . The waste heat recovery generator 42 is connected to the inverter 21 .

[0072] One end of the rear axle 25 is connected to the third wheel. The third wheel hub is connected to the third brake device 31-3. The other end of the rear axle 25 is connected to the fourth wheel. The fourth wheel hub is connected to the fourth brake device 31-4.

[0073] The second generator 20 realizes the coupling and separation of the transmission shaft between the second generator engine 20 and the clutch 26 and the hybrid compound planetary gear set 23 through a pressure plate structure. When the state of charge (SOC) of the power battery pack 22 is lower than the set value (SOC<0.2), the pressure plate presses the transmission shaft, and the second generator 20 is coupled to the engine power system. The torque of the diesel engine 18 transmitted by the engine clutch is used as the power source to drive the second generator 20 to operate. The generated electricity charges the power battery pack 22 through the inverter 21. When the SOC reaches the set upper limit (SOC>0.5), the pressure plate is released, the second generator 20 is decoupled from the engine, the second generator 20 stops running, and charging stops.

[0074] In addition, the electric-generator motor 19 includes a permanent magnet stator and a permanent magnet rotor. The electric-generator motor 19 is a permanent magnet electric-generator integrated machine. When the power battery pack 22 inputs a three-phase voltage to the permanent magnet stator coil of the motor, a rotating magnetic field is generated. Under the action of the same-level repulsion, the permanent magnet rotor passively rotates and presents itself as a motor. That is, when the truck is driven by electricity, the power in the power battery pack 22 is converted into the kinetic energy output of the truck through rotation; when the permanent magnet rotor rotates under the action of external forces, current is induced in the three-phase coil of the stator, presenting itself as a generator, that is, when the truck brakes, electromagnetic damping braking is generated to recover kinetic energy and generate electricity stored in the power battery pack.

[0075] The second generator (20) is designed to ensure the normal operation of cargo refrigeration and truck electrical equipment. The second generator (20) realizes the coupling and separation of the transmission shaft between the second generator engine (20) and the clutch (26) and the hybrid compound planetary gear set (23) through a pressure plate structure. When the state of charge (SOC) of the power battery pack (22) is lower than the set value (SOC<0.2), the pressure plate presses the transmission shaft, and the second generator (20) is coupled to the engine power system. The torque of the diesel engine (18) transmitted by the engine clutch is used as a power source to drive the second generator (20) to operate. The generated electricity is used to charge the power battery pack (22) through the inverter (21). When the SOC reaches the set upper limit (SOC>0.5), the pressure plate is released, the second generator (20) is decoupled from the engine, the second generator (20) stops running, and charging stops.

[0076] The compound planetary gear set 23 can change the mutual motion relationship by changing the fixed elements in the gear system, thereby distributing the torque output by the diesel engine 18 and the electric-generator motor 19, changing the transmission ratio of the engine, the electric-generator motor 19 and the transmission main shaft 30, adjusting the speed of the power components and interrupting the power transmission during braking, so as to realize the truck's neutral gear, gear shifting, braking, reversing and drive mode switching.

[0077] The inverter 21 realizes the conversion of direct current of the power battery pack 22 and alternating current of the electric motor-generator (or first generator) 19, the second generator 20, the waste heat recovery generator 42, the working fluid pump 37, the compressor 41 and other electrical equipment.

[0078] When the truck is driving, it follows the set operation strategy (see the mode switching and control strategy for details). Figure 5 ), the diesel engine 18 and the electric-generator motor 19 output torque according to the quota. The diesel engine 18 rotates, and after the engine clutch 26 adjusts the speed, the torque is transmitted to the compound planetary gear set 23. At the same time, the electric-generator motor rotates to transmit the torque to the compound planetary gear set 23. The compound planetary gear set 23 adjusts and distributes the torque, and transmits the torque to the main reduction gear 28 through the intermediate shaft driven gear 27 to reduce the torque and increase the torque and drive the transmission main shaft 30 to rotate. The transmission main shaft transmits the torque to the differential gear 29 to drive the front axle 24 and the rear axle 25 to make the tires roll, and the car runs normally.

[0079] Figure 4 The figure is a schematic diagram of the waste heat recovery system structure and the cold and heat source coupling form of the hybrid refrigerated truck configuration coupled with the combined cooling and power generation waste heat recovery system. Figure 4As shown, the combined cooling and power waste heat recovery system includes: a preheater 32, a regenerator 33, a heater 34, a turbine 35, a condenser 36, a working fluid pump 37, a liquid storage tank 38, a throttle valve 39, an evaporator 40, a compressor 41, a waste heat recovery generator (or a third generator) 42 and a three-way control valve v1 of the waste heat recovery system.

[0080] The combined cooling and power waste heat recovery system is placed in the truck chassis under the cab and the refrigerated compartment, and the connection relationship of its internal components is as follows: the outlet of the working fluid side of the condenser 36 is connected to the inlet of the liquid storage tank 38, the outlet of the liquid storage tank 38 is connected to the first interface of the three-way control valve v1 of the waste heat recovery system, and the second interface of the three-way control valve v1 of the waste heat recovery system is connected in sequence to the working fluid pump 37, the preheater 32, the high temperature side of the regenerator 33, the heater 34, the turbine 35 and the low temperature side inlet of the regenerator 33; the low temperature side outlet of the regenerator 33 is connected to the condenser 36 to form a closed loop of the power sub-cycle. The main shaft of the turbine 35 is connected to the main shaft of the waste heat recovery generator (third generator) 42; the third interface of the three-way control valve v1 of the waste heat recovery system is connected in sequence to the throttle valve 39, the evaporator 40 and the inlet of the compressor 41, and the outlet of the compressor 41 is connected to the condenser 36 to form a closed loop of the refrigeration sub-cycle. Inside the waste heat recovery system 3, the power sub-cycle and the refrigeration sub-cycle share the condenser 36 and the liquid storage tank 38.

[0081] The exhaust gas recirculation system 13 includes an exhaust gas cooler (not shown in the figure) and an exhaust gas recirculation valve 14. The exhaust gas outlet of the diesel engine 18 is connected to the heater 34, the exhaust gas cooler of the exhaust gas recirculation system 13 and the inlet of the exhaust gas recirculation valve 14 in sequence. The outlet of the exhaust gas recirculation valve 14 is divided into two paths, one of which is connected to the cylinder inlet of the diesel engine 18 after merging with the supplementary air pipeline, and the other is connected to the diesel particulate filter 15 and the selective catalytic reduction denitration system 16 in sequence. The exhaust gas recirculation valve 14 mainly introduces the exhaust gas from the exhaust branch pipe of the diesel engine 18 into the intake pipe and mixes with fresh air, and then enters the combustion chamber, absorbs the heat of the combustion chamber during combustion, reduces the temperature of the combustion chamber, and prevents excessive generation of nitrogen oxides at high temperatures.

[0082] The refrigerant outlet of the evaporator 40 is divided into two paths after passing through the refrigeration distribution control valve v5, one path is connected to the refrigerated compartment refrigeration heat exchanger 10, and the other path is connected to the cab air conditioner 9. The outlet pipeline of the refrigerated compartment refrigeration heat exchanger 10 and the outlet pipeline of the cab air conditioner 9 are combined and connected to the refrigerant inlet of the evaporator 40.

[0083] The power sub-cycle of the combined cooling and power generation waste heat recovery system refers to the cycle part of recovering waste heat to produce electricity. It adopts a transcritical cycle, and its cycle process is as follows: the working fluid passes through the liquid storage tank 38 and is sent to the waste heat recovery system three-way control valve v1 to the power sub-cycle. The working fluid enters the working fluid pump 37 for pressurization, and is then heated to a gaseous state by the cylinder jacket water in the preheater 32, the regenerated steam in the regenerator 33, and the exhaust gas in the heater 34 in turn, thereby forming a high-temperature and high-pressure working fluid. The high-temperature and high-pressure working fluid enters the turbine 35 to expand and do work. The turbine drives the waste heat recovery generator (third generator) 42 to generate electricity and store it in the power battery pack 22. Then the working fluid is discharged from the turbine 35 and cooled in the regenerator 33. Then it returns to the condenser 36 to condense to a liquid state and flows into the liquid storage tank 38 to complete the cycle. The refrigeration sub-cycle refers to the cyclic part that produces refrigeration capacity. It adopts compression refrigeration, and its cyclic process is as follows: the working medium is diverted from the liquid storage tank 38 through the three-way control valve v1 of the waste heat recovery system and enters the throttle valve 39 for throttling and pressure reduction. The pressure is reduced to the two-phase region through the throttle valve 39. The liquid working medium evaporates to a saturated gas state in the evaporator 40 and outputs cold capacity. Then, the low-temperature working medium vapor enters the compressor 41 and is pressurized to superheat, mixed with the high-temperature steam from the regenerator 33, and then condensed to a liquid state by the condenser 36 and returned to the liquid storage tank 38 to complete the cycle.

[0084] There are three modes for waste heat recovery in combined cooling and power generation. The specific process is as follows:

[0085] Pure power mode: The jacket water temperature and exhaust temperature meet the waste heat recovery conditions. If the truck is unloaded or has no cooling demand, the waste heat recovery system switches to pure power mode. The three-way control valve v1 of the waste heat recovery system is adjusted so that the working fluid only flows into the power sub-circulation, and the refrigeration sub-circulation is closed.

[0086] Combined cooling and power supply mode: The jacket water temperature and exhaust temperature meet the waste heat recovery conditions. If the truck is loaded and there is a need for refrigeration, the power sub-cycle and the refrigeration sub-cycle are opened at the same time. The three-way control valve v1 of the waste heat recovery system allocates the refrigeration sub-cycle with the working fluid adapted to the load according to the refrigeration load demand, and the remaining working fluid enters the power cycle. After completing the work of the power sub-cycle and the refrigeration process of the refrigeration sub-cycle, the low-temperature steam from the compressor 41 and the high-temperature steam from the power sub-cycle regenerator 33 are mixed and returned to the condenser 36 to be condensed into liquid state, and then flow into the liquid storage tank 38 to complete the combined cooling and power supply cycle.

[0087] Pure cooling mode: When the jacket water temperature and exhaust temperature cannot meet the minimum recovery conditions for waste heat recovery, the waste heat recovery system switches to pure cooling mode. The three-way control valve v1 of the waste heat recovery system is adjusted so that the working fluid only flows into the refrigeration sub-circulation, and the power sub-circulation is closed.

[0088] The connection relationship between the combined cooling and power waste heat recovery system and the diesel engine cylinder jacket water side is as follows: the diesel engine 18 cylinder jacket water outlet is connected to the first thermostat three-way control valve v2 inlet, the first thermostat three-way control valve v2 outlet is divided into two ways, one is connected to the engine cylinder jacket water inlet, and the other is connected to the preheater 32 high temperature side inlet; the preheater high temperature side outlet is connected to the second thermostat three-way control valve v3 inlet, the second thermostat three-way control valve v3 outlet is divided into two ways, one is connected to the diesel engine cylinder jacket water inlet, and the other is connected to the water tank radiator 11.

[0089] The connection relationship between the combined cooling and power waste heat recovery system and the engine exhaust side is as follows: the exhaust outlet of the diesel engine 18 is connected to the inlet of the heater (exhaust gas recirculation cooler) 34, and the outlet of the heater 34 is sequentially connected to the exhaust gas cooler and the inlet of the exhaust gas recirculation valve 14. The outlet of the exhaust gas recirculation valve 14 is divided into two paths, one of which is sequentially connected to the diesel particulate filter 15 and the selective catalytic reduction denitration system 16, and the other is connected to the cylinder inlet of the diesel engine 18 after merging with the air pipeline.

[0090] The turbine 35 is provided with a turbine bypass control valve v4.

[0091] In order to achieve miniaturization and lightness of the system, the waste heat recovery system adopts a large number of integrated design structures. The system is mainly coupled with the heat exchanger, and the coupling relationship is as follows:

[0092] The heater 34 of the waste heat recovery system 3 is coupled with the EGR exhaust gas cooler of the exhaust gas recirculation system 13 in the exhaust gas treatment system 5 to form a printed plate heat exchanger. The cold end of the heat exchanger is the working medium of the waste heat recovery system, and the hot end is the flue gas. The working medium in the waste heat recovery system is heated to a supercritical state in the heat exchanger, and the flue gas is completely cooled to the temperature required for exhaust gas recirculation. The flow process of the engine exhaust gas is as follows: the exhaust gas of the diesel engine 18 is discharged from the cylinder of the diesel engine 18, cooled to the temperature required for exhaust gas recirculation by the waste heat recovery system heater 34, and then cooled by the exhaust gas cooler of the exhaust gas recirculation system 13, and then divided into two parts after passing through the exhaust gas recirculation valve 14. One part of the exhaust gas is mixed with the newly inhaled air and then sent to the cylinder of the diesel engine 18 for combustion again, and the other part of the exhaust gas is processed by the diesel particulate filter 15 and the selective catalytic reduction denitration system 16 in turn and then discharged to the environment.

[0093] The condenser 36 of the waste heat recovery system 3 and the radiator 11 of the truck cooling system are combined into a new type of truck water tank radiator, which is placed at the front of the vehicle and coupled with an electronic fan to achieve air-cooled heat exchange. In order to reduce the interference of the higher temperature cooling radiator on the condenser, the radiator and the condenser are arranged up and down, and the radiator should be on the upper side of the condenser.

[0094] Figure 5The figure is a schematic diagram of the mode switching and control strategy of the hybrid refrigerated truck coupled with the combined cooling and power generation waste heat recovery system. The refrigerated truck configuration of the present invention also includes an on-board electronic control unit (ECU).

[0095] The operation of the refrigerated truck is mainly controlled by the on-board electronic control unit (ECU) which collects vehicle data information through sensors to control the mode and operation strategy of the truck system.

[0096] Among them, the ECU monitors the truck speed, acceleration and engine speed through electronic vehicle speed and speed sensors, and measures the current and voltage of the power battery pack 22 through sensors to obtain the battery state of charge (SOC). Based on the above data, the torque output of the electric-generator motor 19 and the engine 18 is distributed through the compound planetary gear transmission 23 (planetary gear system) to complete the switching of five driving modes: engine 18 drive, electric-generator motor 19 drive, hybrid power, brake recovery and engine power generation.

[0097] The electronic control unit (ECU) makes instructions according to the set operation strategy based on the measured speed, acceleration, engine speed and SOC data (see the mode switching and control strategy for details). Figure 5 ), distribute the total torque required by the truck, control the engine torque and speed by controlling the engine fuel injection amount, control the torque and speed of the electric-generator motor by controlling the current and voltage, so that the diesel engine 18 and the electric-generator motor 19 output torque according to the quota. When the power of the vehicle power battery pack is higher than the set state of charge value (SOC>0.2), the electric-generator motor 19 is used to drive the vehicle when starting, idling or driving at a low speed (lower than the set speed) (the speed of low speed driving is generally lower than 20km / h). When driving normally (within the set speed range) (the speed of normal driving is generally between 20 and 60km / h), the diesel engine 18 is used to drive the vehicle. When driving at an accelerated speed or a high speed (higher than the set speed range) (the speed of high speed driving is generally greater than 60km / h), the hybrid power system 2 is used to drive the vehicle, which is driven by the diesel engine 18 and the electric-generator motor 19 to achieve maximum acceleration and performance. When the power of the vehicle power battery pack 22 is lower than the set state of charge value (SOC<0.2), in order to ensure the normal operation of the cargo refrigeration and the truck electrical equipment, the diesel engine 18 is used to drive the truck and drive the second generator 20 to charge the power battery pack 22. When the truck decelerates and brakes, the electric-generator motor 19 can recover its braking energy and store it in the power battery pack 22 through the inverter 21.

[0098] In the above operation strategy, the ECU controls the diesel engine 18, the electric-generator motor 19, the second generator 20 and the compound planetary gear set 23 to produce the following actions: Figure 3When the vehicle is stationary, the electric-generator motor 19 rotates forward and has positive torque, driving the diesel engine 18 to start and enter idle speed (replacing the starter motor); when the truck starts, the diesel engine 18 has positive torque, and while warming up the car, it drives the second generator 20 to charge the power battery pack 22; when driving at low speed, the diesel engine 18 and the outermost planetary carrier of the compound planetary gear set 23 are locked, and the electric-generator motor 19 reverses to output positive torque to drive the truck forward; when the low speed is continuously accelerated, the electric-generator motor 19 is directly driven first, and the speed continues to increase until the speed meets the engine's high-efficiency range, and the electric-generator motor 19 drives the diesel engine 18 to run, and then the electric-generator motor 19 and the innermost sun gear of the compound planetary gear set 23 are fixedly locked, and the diesel engine 18 operates efficiently and directly drives the truck; during normal driving, the diesel engine 18 drives and continues to drive in the high-efficiency range. When the power required to drive the truck is less than the output power in the high-efficiency range of the engine, the excess power drives the second generator 20 to output negative torque to charge the power battery pack 22; when the required power is greater than the high-efficiency output power of the diesel engine 18, the electric-generator motor 19 outputs positive torque as a supplement; during sudden acceleration, the electric-generator motor 19 and the diesel engine 18 maintain high speed and high torque at the same time, and output positive torque; when reducing the speed or braking, the wheels have negative torque, and the electric-generator motor 19 outputs negative torque to charge the power battery pack 22.

[0099] The ECU monitors the cylinder jacket water temperature of the diesel engine 18 through the electronic thermostat and the exhaust gas temperature of the diesel engine 18 through the thermocouple temperature sensor of the exhaust pipe at the outlet. The ECU uses the cylinder jacket water and exhaust temperatures of the diesel engine 18 as indicators to adjust the three-way control valve v1 of the waste heat recovery system to control the start, stop and operation of the power and refrigeration sub-cycles of the waste heat recovery system. Figure 4 .

[0100] During the operation of the waste heat recovery system and the refrigeration process, the ECU controls the waste heat recovery system three-way control valve v1 and the turbine bypass control valve v4 on the waste heat recovery working medium side to perform the following actions: adjust the waste heat recovery system three-way control valve v1 according to the set waste heat recovery operation strategy and the power and refrigeration demand load, distribute the working medium flow entering the power cycle subsystem and the refrigeration cycle subsystem, and realize the start and stop and output capacity regulation of the power subsystem and the refrigeration subsystem. When the target refrigeration temperature is lower than the actual temperature of the refrigeration space (that is, there is a refrigeration demand), the refrigeration cycle end b of the waste heat recovery system three-way control valve v1 opens, the refrigeration subsystem starts to adjust the working medium flow according to the required refrigeration load, and the evaporation of the working medium meets the required refrigeration load; when the refrigeration load is no longer required, the refrigeration cycle end b of the waste heat recovery system three-way control valve v1 closes, and the refrigeration stops. When the flue gas temperature and the cylinder jacket water temperature are higher than the set value, the power cycle end a of the waste heat recovery system three-way control valve v1 opens, the working medium flows into the power cycle to start waste heat recovery, and the power cycle working medium does work to convert the waste heat from the exhaust gas and the cylinder jacket water into electrical energy. When the flue gas temperature and the jacket water temperature are both lower than the set value, the power cycle end a of the waste heat recovery system three-way control valve v1 is closed, and the waste heat recovery is terminated. When the flue gas temperature is higher than the set value and the jacket water temperature is lower than the set value, the power cycle end a of the waste heat recovery system three-way control valve v1 is partially opened, the working fluid flow is reduced, the preheater does not operate, and the jacket water bypasses through the small cycle of the cooling system and returns to the engine. The heater meets the exhaust gas heat dissipation requirements of exhaust gas recirculation. When the flue gas temperature is lower than the set value and the jacket water temperature is higher than the set value, the power cycle end a of the waste heat recovery system three-way control valve v1 is partially opened, and the turbine bypass control valve v4a is opened. The working fluid cools the jacket water and exhaust gas respectively through the preheater and heater. The turbine is closed and no electricity is generated.

[0101] The ECU monitors the current temperature in the cabin through the temperature sensor in the refrigerated cabin, determines the temperature difference with the target refrigeration temperature, determines the battery charge state in combination with the current and voltage of the power battery pack 22, and adjusts the flow rate of the coolant entering the cab air conditioner 9 and the refrigerated cabin refrigeration heat exchanger 10 and the fan air supply volume through the refrigeration distribution control valve v5 to control the refrigeration mode.

[0102] The ECU monitors the jacket water temperature through the engine outlet temperature sensor to control the opening of the first thermostat three-way control valve v2 and the second thermostat three-way control valve v3 of the electronic thermostat, changing the jacket water waste heat recovery and utilization and the engine cooling system large and small cycle operation strategy. The preheater 32 of the waste heat recovery system 3 monitors the jacket water temperature through the electronic thermostat to control the three-way control valve to achieve the switching of the jacket water flow path. The control process is as follows: the jacket water flows out from the diesel engine 18 and passes through the first thermostat three-way control valve v2. If the temperature is lower than the set temperature (generally 80°C), the first thermostat three-way control valve v2a end opens b The end is closed, and the cylinder jacket water returns to the diesel engine 18 (the cylinder jacket water completes a small cycle); if the temperature is higher than the set temperature, the first thermostat three-way control valve v2a end is closed and the b end is opened, and the cylinder jacket water enters the waste heat recovery system preheater 32 for recovery and cooling, and then flows into the second thermostat three-way control valve v3. If the temperature is lower than the set temperature, the first thermostat three-way control valve v2a end is opened and the b end is closed, and the cylinder jacket water directly returns to the diesel engine 18 (the cylinder jacket water completes the recovery cycle); if the temperature is higher than the set temperature, the first thermostat three-way control valve v2a end is closed and the b end is opened, and the cylinder jacket water flows into the cooling system water tank radiator 11 to cool to the set temperature and then returns to the diesel engine 18 (the cylinder jacket water completes the recovery cycle + large cycle).

[0103] It should be noted that the functional devices in the various embodiments of the present disclosure may be integrated into one device, or each device may exist physically separately, or two or more devices may be integrated into one device.

[0104] It should be noted that, for the convenience of description, the aforementioned method embodiments are all described as a series of action combinations, but those skilled in the art should be aware that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0105] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0106] The above is a description of a hybrid refrigerated truck configuration and a control method thereof provided by the present invention that is coupled with a combined cooling and power supply waste heat recovery system. For those skilled in the art, according to the ideas of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A hybrid refrigerated truck configuration coupled with a combined cooling and power waste heat recovery system, characterized in that: It includes a hybrid power drive system (2) and a combined cooling and power waste heat recovery system (3); The hybrid drive system (2) comprises a diesel engine (18), an electric-generator motor (19), a second generator (20), an inverter (21), a power battery pack (22), a compound planetary gear set (23), a front axle (24), a rear axle (25), an engine clutch (26), an intermediate shaft driven gear (27), a main reduction gear (28), a differential gear (29), a transmission main shaft (30) and a brake device; The brake device comprises a first brake device (31-1), a second brake device (31-2), a third brake device (31-3) and a fourth brake device (31-4); The output of the front axle (24) is divided into two ends, the first end is connected to the first wheel, the first wheel hub is connected to the first brake device (31-1), the second end of the front axle (24) is connected to the second wheel, and the second wheel hub is connected to the second brake device (31-2); The input end of the front axle (24) is connected in sequence to the differential gear (29), the main reduction gear (28), the intermediate shaft driven gear (27) and the compound planetary gear set (23); one end of the compound planetary gear set (23) is connected to the electric-generator motor (19), and the other end of the compound planetary gear set (23) is connected to the second generator (20); An input end of the second generator (20) is connected to an engine clutch (26); the engine clutch (26) is connected to a diesel engine (18); The output end of the second generator (20) is connected to the inverter (21); the inverter (21) is connected to the power battery pack (22); The compound planetary gear set (23) is connected to the rear axle (25) via the transmission main shaft (30); One end of the rear axle (25) is connected to the third wheel, and the third wheel hub is connected to the third brake device (31-3); the other end of the rear axle (25) is connected to the fourth wheel, and the fourth wheel hub is connected to the fourth brake device (31-4); The combined cooling and power waste heat recovery system comprises a turbine (35) and a waste heat recovery generator (42); the main shaft of the turbine (35) is connected to the main shaft of the waste heat recovery generator (42); and the waste heat recovery generator (42) is connected to an inverter (21).

2. The configuration according to claim 1, characterized in that The second generator (20) achieves coupling and decoupling of the transmission shaft between the second generator (20) and the engine clutch (26) and the compound planetary gear set (23) through a pressure plate structure. When the state of charge SOC of the power battery pack (22) is lower than a set value SOC<0.2, the pressure plate presses the transmission shaft, and the second generator (20) is coupled to the engine power system. The torque of the diesel engine (18) transmitted by the engine clutch is used as a power source to drive the second generator (20) to operate. The generated electricity is used to charge the power battery pack (22) through the inverter (21). When the SOC reaches a set upper limit SOC>0.5, the pressure plate is released, the second generator (20) is decoupled from the engine, the second generator (20) stops running, and charging stops.

3. The configuration according to claim 1, characterized in that: When the truck is running, the diesel engine (18) and the electric-generator motor (19) output torque according to the quota set by the program; the diesel engine (18) rotates, and after the speed is adjusted by the engine clutch (26), the torque is transmitted to the compound planetary gear set (23), and at the same time, the electric-generator motor (19) rotates to transmit the torque to the compound planetary gear set (23), and the compound planetary gear set (23) adjusts and distributes the torque, and transmits the torque to the main reduction gear (28) through the intermediate shaft driven gear (27) to reduce the speed and increase the torque and drive the transmission main shaft (30) to rotate, and the transmission main shaft (30) transmits the torque to the differential gear (29) respectively to drive the front axle (24) and the rear axle (25) to make the wheels roll, and the vehicle runs.

4. The configuration according to claim 1, characterized in that The compound planetary gear set (23) changes the mutual motion relationship by changing the fixed elements in the gear system, distributes the torque output by the diesel engine (18) and the electric-generator motor (19), changes the transmission ratio between the diesel engine (18), the electric-generator motor (19) and the transmission main shaft (30), adjusts the rotation speed of the power component or interrupts the power transmission, thereby realizing the truck hybrid drive.

5. The configuration according to claim 1, characterized in that: The combined cooling and power waste heat recovery system further comprises a preheater (32), a regenerator (33), a heater (34), a condenser (36), a working fluid pump (37), a liquid storage tank (38), a throttle valve (39), an evaporator (40), and a compressor (41); The outlet of the condenser (36) on the working fluid side is connected to the inlet of the liquid storage tank (38), the outlet of the liquid storage tank (38) is connected to the first interface of the three-way control valve (v1) of the waste heat recovery system, the second interface of the three-way control valve (v1) of the waste heat recovery system is connected in sequence to the working fluid pump (37), the preheater (32), the high temperature side of the regenerator (33), the heater (34), the turbine (35) and the inlet of the low temperature side of the regenerator (33), the outlet of the low temperature side of the regenerator (33) is connected to the condenser (36) to form a closed loop of the power sub-cycle; the third interface of the three-way control valve (v1) of the waste heat recovery system is connected in sequence to the throttle valve (39), the evaporator (40) and the inlet of the compressor (41), the outlet of the compressor is connected to the condenser (36) to form a closed loop of the refrigeration sub-cycle; inside the waste heat recovery system (3), the power sub-cycle and the refrigeration sub-cycle share the condenser (36) and the liquid storage tank (38).

6. The configuration according to claim 5, characterized in that The power sub-cycle refers to the cycle part that recovers waste heat to produce electricity. It adopts a transcritical cycle. The working fluid enters the power cycle from the condenser (36) through the three-way control valve (v1) of the waste heat recovery system. After being pressurized by the working fluid pump (37), it is heated to a supercritical state by the preheater (32), the regenerator (33) and the heater (34) in sequence. The resulting high-temperature and high-pressure working fluid drives the turbine (35) to do work to drive the waste heat recovery generator (42) to rotate and generate electricity. The working fluid is cooled in the regenerator (33) and then condensed by the condenser (36) to complete the power cycle. The connection relationship between the combined cooling and power waste heat recovery system and the cylinder jacket water side of the diesel engine (18) is as follows: the cylinder jacket water outlet of the diesel engine is connected to the inlet of the first thermostat three-way control valve (v2), and the outlet of the first thermostat three-way control valve (v2) is divided into two paths, one of which is connected to the cylinder jacket water inlet of the engine, and the other is connected to the high-temperature side inlet of the preheater (32); the high-temperature side outlet of the preheater (32) is connected to the inlet of the second thermostat three-way control valve (v3), and the outlet of the second thermostat three-way control valve (v3) is divided into two paths, one of which is connected to the cylinder jacket water inlet of the engine, and the other is connected to the water tank radiator (11).

7. The configuration according to claim 5, characterized in that The refrigeration sub-cycle refers to the part of the cycle that produces refrigeration capacity. It adopts compression refrigeration. The working fluid enters the refrigeration cycle from the condenser (36) through the three-way control valve (v1) of the waste heat recovery system, is reduced in pressure to the two-phase region by the throttle valve (39), evaporates to a saturated gas state in the evaporator (40) and outputs cold capacity, and then is pressurized to superheat by the compressor (41), mixed with the high-temperature steam from the regenerator (33) of the power sub-cycle, and returns to the condenser (36) to complete the refrigeration sub-cycle.

8. The configuration according to claim 5, characterized in that: The hybrid refrigerated truck configuration also includes an exhaust gas recirculation system (13); the exhaust gas recirculation system includes an exhaust gas cooler and an exhaust gas recirculation valve (14); the exhaust gas cooler is connected to the inlet of the exhaust gas recirculation valve (14); the outlet of the exhaust gas recirculation valve (14) is divided into two paths, one path is connected to the diesel particulate filter (15) and the selective catalytic reduction denitration system (16) in sequence, and the other path is combined with the air pipeline and connected to the inlet of the diesel engine cylinder; The heater (34) in the waste heat recovery system and the exhaust gas cooler in the exhaust gas recirculation system (13) are integrated into a printed plate type heat exchanger, the cold end of the heat exchanger is the working fluid of the waste heat recovery system, and the hot end is the flue gas. The working fluid of the waste heat recovery system is heated to a supercritical state in the heat exchanger, and the flue gas is cooled to a temperature required for exhaust gas recirculation; The exhaust gas flow process of the diesel engine (18) is as follows: the exhaust gas of the diesel engine (18) is discharged from the cylinder of the diesel engine (18), and is cooled to the temperature required for exhaust gas recirculation by the waste heat recovery heater (34). The cooled exhaust gas passes through the exhaust gas cooler and the exhaust gas recirculation valve (14) of the exhaust gas recirculation system (13) in turn and is divided into two parts. One part of the exhaust gas is mixed with air and then sent to the cylinder of the diesel engine (18) for combustion again. The other part of the exhaust gas is treated by the diesel particulate filter (15) and the selective catalytic reduction denitration system (16) and then discharged to the environment.

9. The configuration according to claim 1, characterized in that: The flow process of the cylinder jacket water of the diesel engine (18) is as follows: the cylinder jacket water flows out of the diesel engine (18), passes through the first thermostat three-way control valve (v2), and if the temperature is lower than the set temperature, directly returns to the diesel engine (18), completing a small cycle; if the temperature is higher than the set temperature, it enters the waste heat recovery system preheater (32) for recovery and cooling, and then flows into the second thermostat three-way control valve (v3), and if the temperature is lower than the set temperature, directly returns to the diesel engine (18), completing a recovery cycle; if the temperature is higher than the set temperature, it flows into the water tank radiator (11) to cool to the set temperature and then returns to the diesel engine (18), completing a recovery cycle and a large cycle; The hybrid refrigerated truck configuration also includes a truck electronic control unit, which monitors the truck speed, acceleration and engine speed through electronic vehicle speed and speed sensors, measures the current and voltage of the power battery pack (22) through sensors to obtain the battery charge state, and distributes the torque output of the electric-generator motor (19) and the diesel engine (18) through a compound planetary gearbox (23) based on the above data to complete the switching of five driving modes: diesel engine (18) drive, electric-generator motor (19) drive and hybrid power, brake recovery and engine power generation; The truck electronic control unit monitors the cylinder jacket water temperature of the diesel engine (18) through an electronic thermostat and the exhaust gas temperature of the diesel engine (18) through a thermocouple temperature sensor of the diesel engine (18) outlet exhaust pipe, and adjusts the three-way control valve (v1) of the waste heat recovery system to control the start, stop and operation of the power and refrigeration sub-cycles of the waste heat recovery system based on the cylinder jacket water and exhaust temperatures of the diesel engine (18) as indicators; The truck electronic control unit monitors the current temperature in the compartment through a temperature sensor in the refrigerated compartment (7), determines the temperature difference from the target refrigeration temperature, determines the battery charge state based on the current and voltage of the power battery pack (22), and adjusts the flow rate of the coolant entering the cab air conditioner (9) and the refrigerated compartment refrigeration heat exchanger (10) and the fan air supply volume through the refrigeration distribution control valve (v5) to control the refrigeration mode; The truck electronic control unit monitors the cylinder jacket water temperature of the diesel engine (18) through the diesel engine (18) outlet temperature sensor to control the opening of the electronic thermostat, thereby changing the cylinder jacket water waste heat recovery and utilization and the operation strategy of the large and small cycles of the diesel engine (18) cooling system.

10. The configuration according to claim 1, characterized in that: The refrigerated truck can switch the driving mode of the truck according to different driving conditions. When the power of the on-board power battery pack is higher than the set state of charge value SOC>0.2, the electric-generator motor (19) is used to drive the truck when starting, idling or driving at low speed. The low speed refers to a speed lower than the set speed, and the low speed driving speed is lower than 20 km / h; when driving normally, the diesel engine (18) is used to drive the truck. Normal driving refers to a speed within a set speed range, and the normal driving speed is between 20 and 60 km / h; when accelerating or driving at high speed, the hybrid drive system (2) is used to drive the truck, and the diesel engine (18) is used to drive the truck. The diesel engine (18) and the electric-generator motor (19) are driven together to achieve maximum acceleration and performance, wherein high-speed driving refers to a speed higher than a set speed range, and the speed of high-speed driving is greater than 60 km / h; when the power of the on-board power battery pack (22) is lower than a set state of charge value SOC<0.2, in order to ensure the normal operation of cargo refrigeration and truck electrical equipment, the diesel engine (18) drives the truck to travel and drives the second generator (20) to charge the power battery pack (22); when the truck decelerates and brakes, the electric-generator motor (19) can recover its braking energy and store it in the power battery pack (22) through the inverter (21).

11. The configuration according to claim 1, characterized in that The evaporator (40) outputs the cooling capacity required by the system. The cold end of the evaporator (40) is the working fluid of the waste heat recovery system (3), and the hot end is the refrigerant. The cooling capacity distribution is achieved by controlling the flow rate of the refrigerant entering the cab air conditioner (9) and the refrigerated compartment (7). The cooling capacity is output to the cab (6) and the refrigerated truck to achieve air cooling.

12. The configuration according to claim 1, characterized in that: The hybrid refrigerated truck configuration further includes a refrigerated truck body (1); the refrigerated truck body (1) includes a refrigerated truck cab (6), a refrigerated compartment (7), a chassis (8), a cab air conditioner (9), a refrigerated compartment refrigeration heat exchanger (10), a water tank radiator (11), on-board electrical equipment (12), an exhaust gas treatment system (5) and a fuel tank (17); The front part of the refrigerated truck body (1) is a refrigerated truck cab (6), the cab air conditioner (9) and on-board electrical equipment (12) are installed in the cab (6), and a water tank radiator (11) and a waste heat recovery system condenser (36) are placed in the cab; the rear part of the refrigerated truck body is a refrigerated compartment (7), the front part of the refrigerated compartment (7) is equipped with a refrigerated compartment refrigeration heat exchanger (10), and the compartment refrigeration heat exchanger (10) completes the compartment refrigeration in the form of air cooling by a fan; the bottom part of the refrigerated truck body (1) is a refrigerated truck chassis (8), and the fuel tank (17) and the power battery pack (22) are placed in the lower chassis of the refrigerated compartment (7) at the middle and rear part of the truck; The exhaust gas treatment system (5) comprises an exhaust gas recirculation system (13), an exhaust gas recirculation valve (14), a diesel particulate filter (15) and a selective catalytic reduction denitration system (16); The hybrid drive system (2) is placed in the truck body chassis (8), the diesel engine (18) and the electric-generator motor (19) are placed in the chassis under the cab, and the first brake device (31-1), the second brake device (31-2), the third brake device (31-3) and the fourth brake device (31-4) are all placed inside the wheel hub.

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