Vehicle-mounted waste heat recovery organic Rankine cycle system utilizing internal combustion engine cylinder sleeve water cooling working medium and heat management strategy

Abstract

The invention discloses a vehicle-mounted waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder sleeve water cooling working medium and a heat management strategy. The system comprises an internal combustion engine, a working medium liquid storage tank, a working medium pump, a flue gas heat exchanger, an expansion machine, a condenser, an air cooling radiator, a cooling liquid storage tank, a cooling water pump, an electronic fan, a bypass valve and the like. The invention develops a small and compact efficient waste heat recovery device and a recovery method using the device according to the characteristics of waste heat of an internal combustion engine. In addition, heat management strategies suitable for different automobile working conditions and different waste heat recovery working conditions are further designed, so that the waste heat recovery efficiency is improved to the maximum extent, and the overall energy utilization effect is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat recovery, and in particular to an on-vehicle waste heat recovery organic Rankine cycle system and a thermal management strategy using internal combustion engine cylinder jacket water cooling medium. Background Art

[0002] At present, internal combustion engines are widely used in mobile devices such as vehicles and ships, fixed generator sets, as well as engineering and agricultural machinery due to their advantages such as high efficiency, high energy density and good fuel adaptability.

[0003] The exhaust gas emitted by internal combustion engines usually contains carbon dioxide (CO2), carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NO x ) and other environmental pollutants, and contain a large amount of medium and high temperature waste heat. Therefore, developing energy-saving and emission-reduction technologies for internal combustion engines is of great significance to alleviating my country's energy demand and reducing pollutant emissions.

[0004] Internal combustion engines use the intense combustion of fuels such as gasoline and diesel to rapidly expand the compressed gas in the cylinder to do work and output energy. However, its thermal efficiency is often only about 40%, and the rest of the energy is lost in the form of exhaust waste heat (about 30%) and cylinder jacket water waste heat (about 25%). In this case, it is necessary to use waste heat recovery technology to recycle the thermal energy of internal combustion engine fuel and ultimately improve the energy utilization rate of internal combustion engines.

[0005] The main technical developments of the existing waste heat recovery system include: thermoelectric power generation, Stirling cycle and Rankine cycle. Among them, the Rankine cycle is an effective choice for waste heat recovery of internal combustion engines due to its long development time, mature components and high working efficiency.

[0006] However, there is currently no cycle structure that can efficiently recover the waste heat of the internal combustion engine, achieve reasonable condensation conditions in the vehicle environment, and build a highly integrated waste heat recovery system to ensure its stable operation in practical applications. Summary of the invention

[0007] The purpose of the present invention is to provide an on-board waste heat recovery organic Rankine cycle system and thermal management strategy using the water cooling medium of the cylinder jacket of an internal combustion engine in view of the technical defects of the prior art. The present invention proposes a new solution for recovering only the heat of medium and high temperature exhaust gas and designs a thermal management strategy suitable for different working conditions, so as to realize the recovery and utilization of the thermal energy of the internal combustion engine fuel, significantly improve the energy utilization rate of the internal combustion engine, and achieve the goal of energy saving and consumption reduction.

[0008] To this end, the present invention provides an on-vehicle waste heat recovery organic Rankine cycle system using internal combustion engine cylinder jacket water to cool a working medium, which includes a working medium storage tank, a working medium pump, a flue gas heat exchanger, an expander, a condenser, an internal combustion engine, a cooling water pump, a coolant storage tank, an air-cooled radiator, a cylinder jacket water inlet for the internal combustion engine, an exhaust port for the internal combustion engine, and a cylinder jacket water outlet for the internal combustion engine, an electronic fan, and a bypass valve;

[0009] The organic working fluid is pre-stored in the working fluid storage tank;

[0010] The working fluid inlet of the working fluid pump is connected to the working fluid outlet of the working fluid storage tank;

[0011] The working fluid outlet of the working fluid pump is connected to the working fluid channel inlet a of the flue gas heat exchanger;

[0012] The heat exchange channel inlet c of the flue gas heat exchanger is connected to the exhaust port for the internal combustion engine on the internal combustion engine;

[0013] The heat exchange channel outlet d of the flue gas heat exchanger is connected to the external environment;

[0014] The working fluid channel outlet b of the flue gas heat exchanger is connected to the working fluid inlet of the expander and the working fluid inlet a of the condenser respectively;

[0015] The working fluid outlet of the expander is connected to the working fluid inlet a of the condenser;

[0016] The working fluid outlet b of the condenser is connected to the working fluid inlet of the working fluid storage tank;

[0017] The coolant storage tank stores the coolant in advance;

[0018] The coolant outlet of the coolant storage tank is connected to the coolant inlet of the cooling water pump;

[0019] The coolant outlet of the cooling water pump is connected to the cylinder jacket water inlet of the internal combustion engine and the coolant inlet c of the condenser respectively;

[0020] The coolant outlet d of the condenser is connected to the coolant inlet of the air-cooled radiator and the coolant inlet of the coolant storage tank respectively;

[0021] The internal combustion engine jacket water outlet on the internal combustion engine is connected to the coolant inlet of the air-cooled radiator and the coolant inlet of the coolant storage tank respectively;

[0022] The coolant outlet of the air-cooled radiator is connected to the coolant inlet of the coolant storage tank;

[0023] The two ends of the coolant channel in the internal combustion engine are respectively the cylinder jacket water inlet for the internal combustion engine and the cylinder jacket water outlet for the internal combustion engine;

[0024] At least one electronic fan is arranged behind the air-cooled radiator.

[0025] In addition, the present invention also provides a thermal management strategy for an on-vehicle waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder jacket water cooling medium as described above, including working mode 1: a working mode when the vehicle is in a low temperature environment and the vehicle is cold started;

[0026] Working mode 1, corresponding specific thermal management strategies are as follows:

[0027] Close the first bypass valve to connect the heat exchange channel inlet c of the flue gas heat exchanger with the exhaust port for the internal combustion engine on the internal combustion engine; open the second bypass valve to disconnect the working medium channel outlet b of the flue gas heat exchanger from the working medium inlet of the expander, and the working medium directly enters the condenser; open the third bypass valve to allow the coolant at the outlet d of the condenser to be combined with the coolant at the cylinder jacket water outlet of the internal combustion engine and then flow into the inlet of the coolant storage tank; keep the electronic fan closed;

[0028] The high-temperature flue gas discharged from the exhaust port of the internal combustion engine is all passed into the heat exchange channel of the flue gas heat exchanger to exchange heat with the organic working fluid in the working fluid channel of the flue gas heat exchanger. The organic working fluid does not enter the expander to perform work, but is directly transported to the condenser. The coolant transported by the cooling water pump is heated by the condenser. After passing through the third bypass valve, the coolant flows through the branch and returns to the coolant storage tank. The heat is not dissipated through the air-cooled radiator, thereby achieving the purpose of indirectly heating the coolant with the exhaust gas. With the circulating organic working fluid as the intermediate carrier, the heat is gradually transferred from the high-temperature exhaust gas to the coolant, so that the coolant quickly reaches the safe operating temperature range during the cold start stage of the automobile, effectively increasing the coolant temperature, reducing the wear during cold start, and extending the engine life.

[0029] In addition, the present invention also provides a thermal management strategy for the on-board waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium as described above, including working mode 2: a working mode when the vehicle and the waste heat recovery organic Rankine cycle system transition from a startup state to a normal working state;

[0030] Working mode 2, as follows

[0031] The first bypass valve on the hot side of the flue gas heat exchanger is kept closed, so that all the exhaust gas discharged from the internal combustion engine exhaust port of the internal combustion engine enters the heat exchange channel of the flue gas heat exchanger, exchanges heat with the organic working medium in the working medium channel of the flue gas heat exchanger, and heats the organic working medium;

[0032] The second bypass valve on the working medium inlet side of the expander gradually reduces its opening from an open state to 0, so that all the gaseous organic working medium enters the expander to perform work;

[0033] The third bypass valve at the coolant inlet of the air-cooled radiator gradually reduces its opening from the open state to 0, and the electronic fan remains closed;

[0034] The exhaust steam of the working fluid outputted by the organic working fluid in the expander after expansion and work enters the condenser and then enters the working fluid storage tank, and then is transported to the flue gas heat exchanger by the working fluid pump. The heated working fluid enters the expander to work, completing the organic Rankine cycle. The coolant delivered by the cooling water pump is heated by the condenser. After the third bypass valve at the coolant inlet of the air-cooled radiator is closed, the coolant flows through the air-cooled radiator to dissipate heat, and then returns to the condenser and the cylinder of the internal combustion engine through the coolant storage tank to complete the coolant cycle.

[0035] In addition, the present invention also provides a thermal management strategy for an on-board waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder jacket water cooling medium as described above, including a third working mode: a working mode when the vehicle's headwind cooling condition is insufficient, that is, when the headwind flow rate is insufficient;

[0036] Working mode three includes at least one of the following two working modes:

[0037] Working mode 1: Increase the cooling air flow by turning on and adjusting the gear position of the electronic fan;

[0038] Working mode 2: By opening and increasing the opening of the first bypass valve on the hot side of the flue gas heat exchanger, part of the flue gas is bypassed to reduce the cooling load of the air-cooled radiator; at the same time, the second bypass valve on the working fluid inlet side of the expander remains closed, and the third bypass valve at the coolant inlet of the air-cooled radiator remains closed.

[0039] In addition, the present invention also provides a thermal management strategy for an on-board waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder jacket water cooling medium as described above, including a fourth working mode: a working mode when the vehicle's headwind cooling condition is excessive, that is, when the headwind flow rate is too large or the engine is under low load;

[0040] Working mode 4 includes at least one of the following two working modes:

[0041] Working mode three: turn off the electronic fan;

[0042] Working mode 4: Increase the opening size of the third bypass valve at the coolant inlet of the air-cooled radiator; at the same time, keep the first bypass valve on the hot side of the flue gas heat exchanger closed, and keep the second bypass valve on the working fluid inlet side of the expander closed.

[0043] It can be seen from the technical solution provided by the present invention above that, compared with the prior art, the present invention provides an on-vehicle waste heat recovery organic Rankine cycle system and thermal management strategy that utilizes internal combustion engine cylinder jacket water cooling medium. The system is scientifically designed and can effectively recover the waste heat (exhaust waste heat) of the internal combustion engine under the on-vehicle operating environment, realize the recovery and utilization of the thermal energy of the internal combustion engine fuel, and significantly improve the energy utilization rate of the internal combustion engine, which has great practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic structural diagram of an on-vehicle waste heat recovery organic Rankine cycle system using internal combustion engine cylinder jacket water cooling medium provided by the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0047] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0049] See also Figure 1 The present invention provides an on-vehicle waste heat recovery organic Rankine cycle system using internal combustion engine cylinder jacket water to cool a working medium, which is applied to a vehicle and includes: a working medium storage tank 1, a working medium pump 2, a flue gas heat exchanger 3, an expander 4, a condenser 5, an internal combustion engine 6, a cooling water pump 7, a coolant storage tank 8, an air-cooled radiator 9, a cylinder jacket water inlet 11 for the internal combustion engine, an exhaust port 12 for the internal combustion engine, and a cylinder jacket water outlet 13 for the internal combustion engine, a bypass valve 14, a bypass valve 15, and a bypass valve 16;

[0050] The working fluid storage tank 1 stores the organic working fluid in advance;

[0051] In a specific implementation, the organic working fluid is cyclopentane working fluid as a circulating working fluid;

[0052] It should be noted that the boiling point of cyclopentane working fluid at atmospheric pressure is 49.15°C, the critical temperature is 238.57°C, and the critical pressure is 4.515 MPa.

[0053] The working fluid inlet of the working fluid pump 2 is connected to the working fluid outlet of the working fluid storage tank 1;

[0054] The working fluid outlet of the working fluid pump 2 is connected to the working fluid channel inlet a of the flue gas heat exchanger 3;

[0055] It should be noted that the flue gas heat exchanger 3 has a working fluid channel and a heat exchange channel (the working fluid channel and the heat exchange channel are in contact with each other, and heat can be transferred, i.e., heat exchange, between the two), the working fluid inlet of the working fluid pump 2 is connected to the working fluid storage tank 1, and the working fluid outlet of the working fluid pump 2 is connected to the working fluid channel inlet of the flue gas heat exchanger 3. The working fluid pump 2 is used to pump the circulating working fluid in the working fluid storage tank 1 into the working fluid channel of the flue gas heat exchanger 3.

[0056] The heat exchange channel inlet c of the flue gas heat exchanger 3 is connected to the internal combustion engine exhaust port 12 on the internal combustion engine 6;

[0057] The heat exchange channel outlet d of the flue gas heat exchanger 3 is connected to the external environment;

[0058] It should be noted that the exhaust gas from the internal combustion engine 6 can enter the heat exchange channel of the flue gas heat exchanger 3 through the exhaust port 12 for the internal combustion engine, and perform heat exchange as a heat source medium (specifically, perform heat exchange with the working medium in the working medium channel). The heat exchange channel outlet d of the flue gas heat exchanger 3 is connected to the external environment. Through this process, the exhaust gas of the internal combustion engine can be effectively recovered and utilized through the flue gas heat exchanger 3 before entering the external environment.

[0059] The working medium channel outlet b of the flue gas heat exchanger 3 is connected to the working medium inlet of the expander 4 and the working medium inlet a of the condenser 5 respectively;

[0060] The working fluid outlet of the expander 4 is connected to the working fluid inlet a of the condenser 5;

[0061] The working fluid outlet b of the condenser 5 is connected to the working fluid inlet of the working fluid storage tank 1;

[0062] It should be noted that the circulating working fluid is transported from the working fluid storage tank 1 to the flue gas heat exchanger 3 through the working fluid pump 2, and the working fluid channel outlet b of the flue gas heat exchanger 3 is connected to the working fluid inlet of the expander 4, so that the high-temperature and high-pressure gaseous working fluid output by the flue gas heat exchanger 3 expands and performs work in the expander 4. The working fluid outlet of the expander 4 is connected to the working fluid inlet a of the condenser 5, and the working fluid outlet b of the condenser 5 is connected to the working fluid storage tank 1. After being cooled by the condenser 5, the working fluid enters the working fluid storage tank 1, completing the organic Rankine cycle for recovering exhaust waste heat.

[0063] The coolant storage tank 8 stores coolant in advance, which is used for circulating cooling of the cylinder block of the internal combustion engine and for replenishing the coolant lost in the system due to evaporation or leakage;

[0064] It should be noted that the main components of the coolant include water, ethylene glycol or propylene glycol, preservatives, antifoaming agents, lubricants and colorants. These components work together to achieve effective thermal management and system protection. In the system of the present invention, the additional function is to act as a cooling medium to condense the organic working fluid in the ORC cycle (i.e., Organic Rankine Cycle).

[0065] The coolant outlet of the coolant storage tank 8 is connected to the coolant inlet of the cooling water pump 7;

[0066] The coolant outlet of the cooling water pump 7 is connected to the internal combustion engine jacket water inlet 11 on the internal combustion engine 6 and the coolant inlet c of the condenser 5 respectively;

[0067] The coolant outlet d of the condenser 5 is connected to the coolant inlet of the air-cooled radiator 9 and the coolant inlet of the coolant storage tank 8 respectively;

[0068] The internal combustion engine jacket water outlet 13 on the internal combustion engine 6 is connected to the coolant inlet of the air-cooled radiator 9 and the coolant inlet of the coolant storage tank 8 respectively;

[0069] The coolant outlet of the air-cooled radiator 9 is connected to the coolant inlet of the coolant storage tank 8 .

[0070] It should be noted that the cooling water pump 7 is a core component of the entire internal combustion engine cooling system. It drives the coolant to circulate in the system through mechanical or electric drive.

[0071] It should be noted that the internal combustion engine 6 has coolant channels therein, and the circulating coolant absorbs heat from engine parts such as the cylinder block, cylinder liner and cylinder head through these channels.

[0072] It should be noted that the heat exchange channel in the condenser 5 flows with coolant to condense the circulating working fluid, so that the circulating working fluid is converted from gas to liquid. At the same time, due to the heat release of condensation, heat exchange is carried out with the coolant, so that the temperature of the coolant increases.

[0073] It should be noted that the coolant in the air-cooled radiator 9 releases the absorbed heat into the atmosphere when flowing through the radiator. The air-cooled radiator 9 is usually located in front of the engine, close to the front grille of the vehicle, so as to utilize air flow for cooling during driving.

[0074] It should be noted that, under the pressurized action of the cooling water pump 7, the coolant starts from the coolant storage tank 8, and a part of it flows through the cylinder jacket water inlet 11 for the internal combustion engine, the internal combustion engine 6 (specifically, the internal combustion engine 6 has its own coolant channel), the cylinder jacket water outlet 13 for the internal combustion engine, and the other part flows through the condenser 5. The two parts of coolant converge at the air-cooled radiator 9 and finally flow back to the coolant storage tank 8, thereby completing the coolant circulation of the engine (i.e., the internal combustion engine 6).

[0075] In the present invention, in specific implementation, the working fluid inlet of the working fluid storage tank 1 is located at the upper part of the tank body of the working fluid storage tank 1;

[0076] The working fluid outlet of the working fluid storage tank 1 is located at the bottom of the tank body of the working fluid storage tank 1 .

[0077] In the present invention, in a specific implementation, the on-board waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling working medium further includes a first bypass valve 14;

[0078] The heat exchange channel inlet c of the flue gas heat exchanger 3 is connected to the second interface b of the first bypass valve 14;

[0079] The first interface a of the first bypass valve 14 is connected to the external environment;

[0080] The third port c of the first bypass valve 14 is connected to the internal combustion engine exhaust port 12 on the internal combustion engine 6 .

[0081] In the present invention, in a specific implementation, the on-board waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling working medium further includes a second bypass valve 15;

[0082] The outlet b of the working medium channel of the flue gas heat exchanger 3 is connected to the first interface a of the second bypass valve 15;

[0083] The second interface b of the second bypass valve 15 is connected to the working medium inlet a of the condenser 5;

[0084] The third port c of the second bypass valve 15 is connected to the working medium inlet of the expander 4 .

[0085] In the present invention, in a specific implementation, the on-board waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling working medium further includes a third bypass valve 16;

[0086] The coolant inlet of the air-cooled radiator 9 is connected to the third interface c of the third bypass valve 16;

[0087] The first interface a of the third bypass valve 16 is connected to the coolant inlet of the coolant storage tank 8;

[0088] The second port b of the third bypass valve 16 is connected to the coolant outlet d of the condenser 5 and the jacket water outlet 13 for the internal combustion engine on the internal combustion engine 6, respectively.

[0089] In the present invention, in a specific implementation, the internal combustion engine 6 has two ends of a coolant channel, which are a cylinder jacket water inlet 11 for the internal combustion engine and a cylinder jacket water outlet 13 for the internal combustion engine.

[0090] In the present invention, in specific implementation, the first bypass valve 14, the second bypass valve 15 and the third bypass valve 16 are all three-way valves.

[0091] In the present invention, in a specific implementation, at least one electronic fan 10 is arranged behind the air-cooled radiator 9 .

[0092] It should be noted that the present invention implements forced convection cooling on the air-cooled radiator 9 by using a switch-controllable electronic fan 10. This design solves the contradiction between the deterioration of the heat dissipation of the working fluid in the condenser 5 and the cylinder jacket water in the air-cooled radiator 9 and the condensation conditions required by the organic Rankine cycle (ORC) under high-load operating conditions.

[0093] In order to more clearly understand the technical solution of the present invention, the working principle of the present invention is explained below.

[0094] The exhaust gas of the internal combustion engine 6 is introduced into the heat exchange channel of the flue gas heat exchanger 3 as a heat source medium. The circulating working fluid in the working fluid storage tank 1 enters the working fluid channel of the flue gas heat exchanger 3 after being pressurized by the working fluid pump 2, and exchanges heat with the heat source medium (i.e., exhaust gas) in the flue gas heat exchanger 3. A first bypass valve 14 is arranged on the hot side of the flue gas heat exchanger 3. The opening of the first bypass valve 14 can be adjusted according to the size of the cold end heat dissipation load of the system and the feedback of the cold start demand, and the flue gas flow entering the waste heat recovery system can be reasonably regulated to meet the requirements of efficient and stable operation of the waste heat recovery system. The organic working fluid flows through the working fluid channel of the flue gas heat exchanger 3, and the outlet of the working fluid channel of the flue gas heat exchanger 3 is connected to the working fluid inlet of the expander 4. The high-temperature and high-pressure steam enters the expander 4 to expand and do work. The working fluid outlet of the expander 4 is connected to the working fluid channel inlet of the condenser 5; the working fluid is cooled to a liquid phase by the condenser 5 and enters the working fluid storage tank 1. At this point, the organic Rankine cycle is completed.

[0095] The working fluid inlet of the expander 4 is provided with a second bypass valve 15. The main function of the second bypass valve 15 at the inlet of the expander is to adjust the flow rate and pressure of the working fluid entering the expander to protect the safe operation of the expander under different working conditions. When the working fluid flow rate or pressure is too high, the second bypass valve 15 opens to divert part of the working fluid to bypass the expander to avoid overload operation of the expander. In addition, the second bypass valve 15 can also be used to control the inlet parameters of the expander during vehicle startup, shutdown or low-load conditions to ensure the safety, stability and effective output of the system and reduce mechanical stress and loss.

[0096] In the above system, the cold side medium of the condenser 5 comes from the diversion of the cylinder jacket water (coolant). The cylinder jacket water (coolant) in the original engine cooling system circulates through the cooling water pump 7 to drive the coolant, and is transported from the coolant storage tank 8 to the cooling water jacket in the cylinder block and cylinder head of the engine (i.e., the internal combustion engine 6). When the coolant flows through the cooling water jacket around the cylinder block and cylinder head, the coolant absorbs the heat generated during the engine combustion process, thereby taking away the heat, preventing the engine from overheating and maintaining the engine running within the optimal temperature range. The coolant that has absorbed the heat flows to the air-cooled radiator 9 through the pipeline of the cooling system.

[0097] The air-cooled radiator 9 is usually located at the front of the engine, close to the front grille of the vehicle, so as to utilize air flow for cooling during driving. In the air-cooled radiator 9, the coolant transfers the heat absorbed by it to the air flow passing through the air-cooled radiator 9. This process is completed by the natural wind during driving of the vehicle or the air flow forced by the electronic fan 10 behind the air-cooled radiator 9. The temperature of the coolant cooled by the air-cooled radiator 9 is reduced, and then it is pumped back to the cooling water jacket in the cylinder block and cylinder head of the engine (i.e., the internal combustion engine 6) by the cooling water pump 7, thereby completing a cooling cycle.

[0098] It should be noted that in the original system of the car, in order to ensure the effective regulation of the coolant temperature, the cooling system is usually equipped with a thermostat (temperature control valve). The thermostat adjusts the flow direction of the coolant according to its temperature: when the coolant temperature is low, the thermostat guides it back to the engine to help it quickly reach the normal operating temperature (small cycle); when the coolant temperature reaches the set value, the thermostat opens to allow the coolant to flow to the air-cooled radiator for heat dissipation (large cycle). Through these processes, the cylinder jacket water circulation system can effectively manage the operating temperature of the engine and ensure its performance and reliability under various operating conditions.

[0099] In the circulation system provided by the present invention, the engine cooling system does not need to be equipped with a thermostat. The coolant is split at the outlet of the cooling water pump 7. One part flows through the coolant channel in the cylinder of the engine (i.e., the internal combustion engine 6) to absorb the heat of the engine cylinder, cylinder liner, cylinder head and other parts; the other part flows through the condenser 5 in the organic Rankine cycle (ORC) system to exchange heat with the exhaust steam after expansion and work in the expander 4 to condense the working fluid. Finally, the two coolants are connected in parallel at the inlet of the air-cooled radiator 9, and then cooled by the incoming air in the air-cooled radiator 9, and finally enter the coolant storage tank 8, and are pressurized by the cooling water pump 7 and split to complete the entire cycle.

[0100] In the present invention, a third bypass valve 16 is provided at the inlet of the air-cooled radiator 9. The opening of the bypass valve is adjusted according to the size of the cold-end heat dissipation load of the system and the feedback of the cold start demand, and the temperature of the coolant entering the cooling water jacket of the internal combustion engine is reasonably regulated to be controlled within the temperature range of safe and efficient operation of the engine, so as to meet the requirements of efficient and stable operation of the coupling system.

[0101] In the present invention, cyclopentane is used as the circulating medium, and the heat exchange channel of the condenser 5 in the circulation system of the present invention is connected with the partially diverted jacket water (specifically, the jacket water from the coolant storage tank 8 and delivered by the cooling water pump 7). This design can significantly reduce the total volume of the waste heat recovery system and improve the integration of the system, thereby greatly improving its application possibility on the mobile platform. Compared with the fixed platform, this design eliminates the need for the condensate tank, cooling water pump and related pipelines, which helps to reduce the total weight of the system and reduce the complexity of the structure and layout.

[0102] In the present invention, the ORC cycle of the present invention is only a single loop, which eliminates the absorption of the heat of the cylinder jacket water and uses the coolant as a cooling medium to cool the circulating working fluid. Before starting the waste heat recovery system, a certain volume of cyclopentane organic working fluid needs to be filled into the working fluid storage tank 1. During the system trial operation, the liquid level of the working fluid storage tank 1 is monitored in real time. If it is lower than the limit value, the system needs to be shut down and the working fluid needs to be replenished in time.

[0103] In the ORC loop, the circulating working fluid from the working fluid storage tank 1 enters the flue gas heat exchanger 3 under the booster delivery of the working fluid pump 2, and is used to absorb the high-temperature heat from the exhaust gas of the internal combustion engine (i.e., the waste heat of the exhaust gas discharged from the exhaust port 12 of the internal combustion engine). Then, the high-temperature and high-pressure gaseous circulating working fluid output by the flue gas heat exchanger 3 enters the expander 4 to expand and do work, and finally the exhaust steam after doing work (i.e., the steam that has done work) enters the condenser 5 for condensation, and finally enters the working fluid storage tank 1 to complete the waste heat recovery cycle.

[0104] In the present invention, in the cylinder jacket water circulation loop, a portion of the coolant from the coolant storage tank 8 enters the internal combustion engine 6 under the delivery of the cooling water pump 7 to absorb the heat around the cylinder jacket, thereby preventing the engine from overheating and controlling the engine temperature to a normal operating range, and the other portion enters the heat exchange channel of the condenser 5 to cool the circulating working fluid. Then, the coolant flowing out of the cylinder jacket water outlet 13 of the internal combustion engine 6 and the coolant flowing out of the heat exchange channel of the condenser 5 are combined together and then enter the air-cooled radiator 9 to dissipate heat by convection with the air. After the heat dissipation is completed, it returns to the coolant storage tank 8 to complete the cylinder jacket water (coolant) circulation.

[0105] It should be noted that the present invention is an efficient waste heat recovery system for recycling high-quality waste heat. At the same time, it can be applied to internal combustion engines in some mobile devices, such as heavy trucks, ships, etc., to meet users' requirements for miniaturization and integration of waste heat recovery systems. The system of the present invention is a small, compact and efficient waste heat recovery device developed based on the characteristics of internal combustion engine waste heat and internal combustion engine cooling systems.

[0106] In addition, the present invention also provides a thermal management strategy suitable for different vehicle operating conditions and different waste heat recovery conditions, which can maximize the waste heat recovery efficiency of the internal combustion engine and optimize the overall energy utilization effect. In addition, the waste heat recovery system of the present invention is intended to utilize waste heat to improve the efficiency of the power transmission system and reduce the fuel consumption of the vehicle.

[0107] It should be noted that the system of the present invention has also developed different thermal management strategies through the first bypass valve 14, the second bypass valve 15 and the third bypass valve 16 with different functions to ensure that the cylinder block of the internal combustion engine is not damaged while allowing the ORC cycle to run smoothly and efficiently and improve the overall energy utilization efficiency.

[0108] Based on the above-mentioned on-vehicle waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium provided by the present invention, the present invention also provides a thermal management strategy for the on-vehicle waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium, which includes the following working modes (specifically, the working modes corresponding to operation under different working conditions):

[0109] 1. Working mode 1: When the car is in a low temperature environment, the working mode of the car is cold-started;

[0110] It should be noted that cold starting a car means starting the car when the engine is in a low temperature state, usually after the vehicle has not been running for a long time or in cold weather. During a cold start, the viscosity of the engine's lubricating oil is higher, and the fuel injection and the formation of the mixed gas are not as smooth as during a hot start, which may lead to difficulty in starting, increased emissions, and increased engine wear. Therefore, the contents of a cold start usually include: adjusting the fuel mixture ratio, increasing the engine speed to ensure a smooth start, and using auxiliary measures such as an electric heating device to improve the starting performance. In the present invention, the cold start can be accelerated by the following operations.

[0111] Working mode 1, as follows:

[0112] Close the first bypass valve 14 (i.e., not bypassing), so that the heat exchange channel inlet c of the flue gas heat exchanger 3 is connected to the internal combustion engine exhaust port 12 on the internal combustion engine 6; open the second bypass valve 15 (i.e., bypassing), so that the working medium channel outlet b of the flue gas heat exchanger 3 is not connected to the working medium inlet of the expander 4, and the working medium directly enters the condenser 5; open the third bypass valve 16 (i.e., bypassing), so that the coolant at the outlet d of the condenser 5 and the coolant at the cylinder jacket water outlet 13 of the internal combustion engine are combined and flow into the inlet of the coolant storage tank 8. The electronic fan 10 remains closed;

[0113] The high-temperature flue gas discharged from the internal combustion engine exhaust port 12 of the internal combustion engine 6 is all passed into the heat exchange channel of the flue gas heat exchanger 3 to exchange heat with the organic working medium in the working medium channel of the flue gas heat exchanger 3. The organic working medium does not enter the expander 4 to perform work, but is directly transported to the condenser 5. The coolant transported by the cooling water pump 7 is heated by the condenser 5. After passing through the third bypass valve 16, the coolant flows through the branch and returns to the coolant storage tank 8. The heat is not dissipated through the air-cooled radiator 6, thereby achieving the purpose of indirectly heating the coolant with the exhaust gas. With the circulating organic working medium as the intermediate carrier, the heat is gradually transferred from the high-temperature exhaust gas to the coolant, so that the coolant quickly reaches the safe operating temperature range during the cold start stage of the automobile, effectively increases the coolant temperature, reduces the wear during cold start, and prolongs the engine life.

[0114] It should be noted that regarding the cold start condition of the vehicle: in the cold winter ambient temperature, the engine and its lubricating oil, coolant, etc. are at ambient temperature, which is far below its normal operating temperature. The cold start process will face some unique challenges. During cold start, the cylinder jacket water (coolant) heats up very slowly and takes a long time, while the exhaust gas after the engine fuel is burned can reach 350-500°C in a short time. At this time, the system of the present invention can transfer the high-temperature exhaust gas heat absorbed by the system to the coolant through the condenser 5, realize the use of circulating working fluid to heat the coolant, and gradually transition the engine from a low temperature state to a working condition of normal operating temperature. The first bypass valve 14 on the hot side of the flue gas heat exchanger 3 remains closed, and all exhaust gases enter the flue gas heat exchanger 3 to heat the working medium. The second bypass valve 15 on the inlet side of the expander 4 is opened, and all working medium does not enter the expander 4 (the expander is in the shutdown state), and directly enters the condenser 5 through the pipeline. The third bypass valve 16 at the inlet of the air-cooled radiator 9 is opened, and the heated coolant does not enter the air-cooled radiator 9 to dissipate heat, but flows through the branch, passes through the coolant storage tank 8 and the cooling water pump 7, and is partially diverted back to the engine (i.e., the internal combustion engine 6) to heat the cylinder block, and the electronic fan 10 remains closed.

[0115] Therefore, through the strategy of the above working mode 1, the flue gas and the circulating organic working medium fully exchange heat in the flue gas heat exchanger 3, and the circulating organic working medium and the coolant fully exchange heat in the condenser 5. Therefore, in extreme cold weather, the coolant can be quickly heated up and quickly reach the temperature operating range of the coolant, accelerating the cold start.

[0116] 2. Working mode 2: The working mode when the vehicle and waste heat recovery organic Rankine cycle system transitions from the startup state to the normal working state;

[0117] It should be noted that after the car's engine is started, the car runs at a low speed, the engine temperature gradually increases, the vehicle begins to accelerate smoothly, and then gradually increases the speed and load to transition to the normal working stage (the engine reaches the optimal operating temperature and enters a stable working state).

[0118] For the organic Rankine cycle system, when the organic Rankine cycle is started, the expander 4 is closed, and the system first stores heat and pressure of the working fluid. When the expander inlet parameters are met, the expander 4 can be turned on; during normal operation, the waste heat recovery system can output work steadily.

[0119] Working mode 2, as follows:

[0120] The first bypass valve 14 on the hot side of the flue gas heat exchanger 3 is kept closed, so that all the exhaust gas discharged from the internal combustion engine exhaust port 12 of the internal combustion engine 6 enters the heat exchange channel of the flue gas heat exchanger 3, exchanges heat with the organic working medium in the working medium channel of the flue gas heat exchanger 3, and heats the organic working medium;

[0121] The second bypass valve 15 on the working medium inlet side of the expander 4 gradually reduces its opening from an open state to 0 (specifically, according to the real-time monitored working medium temperature and working medium pressure state, the opening is gradually reduced from an open state to 0, that is, it is finally closed and no longer bypassed), so that all the gaseous organic working medium enters the expander 4 to perform work; wherein, the higher the temperature and pressure of the working medium, the smaller the opening of the corresponding second bypass valve 15.

[0122] It should be noted that, in the present invention, a temperature sensor and a pressure sensor may be installed at the inlet of the expander 4 to monitor the temperature and pressure data of the working fluid in real time.

[0123] The third bypass valve 16 at the coolant inlet of the air-cooled radiator 9 gradually reduces its opening from an open state to 0 (i.e., it is finally closed and no longer bypassed), and the electronic fan 10 remains closed;

[0124] The exhaust steam of the working medium outputted by the organic working medium during expansion and work in the expander 4 enters the condenser 5, enters the working medium storage tank 1 after condensation, and is then transported to the flue gas heat exchanger 3 by the working medium pump 2. The heated working medium enters the expander 4 to perform work, completing the organic Rankine cycle. The coolant transported by the cooling water pump 7 is heated by the condenser 5. After the third bypass valve 16 at the coolant inlet of the air-cooled radiator 9 is closed (i.e., not bypassed), the coolant flows through the air-cooled radiator 9 to dissipate heat, and then returns to the condenser 5 and the cylinder of the internal combustion engine 6 (specifically, the coolant channel in the cylinder of the internal combustion engine 6) through the coolant storage tank 8 and the cooling water pump 7 to complete the coolant circulation.

[0125] It should be noted that in working mode 2, all the high-temperature flue gas discharged from the internal combustion engine exhaust port 12 of the internal combustion engine 6 is passed into the flue gas heat exchanger 3 to exchange heat with the organic working fluid, gradually increasing the proportion of the organic working fluid entering the expander 4 to perform work until the second bypass valve 15 on the working fluid inlet side of the expander 4 is completely closed.

[0126] Through the above working mode 2 strategy, the vehicle and the waste heat recovery system can be successfully coupled within the safe operating range. On the one hand, it can improve energy efficiency: through the waste heat recovery system, the waste heat generated by the vehicle engine during operation can be used to improve the overall energy efficiency; on the other hand, it can reduce fuel consumption: it can effectively reduce fuel consumption and reduce vehicle operating costs; achieve energy conservation and emission reduction.

[0127] It should be noted that by applying the thermal management strategy of the present invention, the power system and waste heat recovery system of the vehicle can be effectively coupled under safe operating conditions to form a collaborative whole. Specifically, this means that the energy transfer and control mechanism between the two can be kept within a safe range and will not cause overheating, failure or other potential safety hazards of the system.

[0128] 3. Working mode 3: The working mode when the vehicle's headwind cooling condition is insufficient, that is, when the headwind flow is insufficient;

[0129] Working mode three includes at least one of the following two working modes:

[0130] Working mode 1: increasing the cooling air flow rate by turning on and adjusting the gear position of the electronic fan 10;

[0131] Working mode 2: by opening and increasing the opening degree of the first bypass valve 14 on the hot side of the flue gas heat exchanger 3 (i.e. gradually increasing the opening degree from the closed state), part of the flue gas is bypassed to reduce the cooling load of the air-cooled radiator 9; at the same time, the second bypass valve 15 on the working medium inlet side of the expander 4 remains closed, and the third bypass valve 16 at the coolant inlet of the air-cooled radiator 9 remains closed;

[0132] It should be noted that working mode 1 or working mode 2, or the two control strategies can be implemented, so that the net work output by the thermal management system coupled with ORC is maximized within a safe range.

[0133] It should be noted that when the engine (i.e., the internal combustion engine 6) is operating at high load, the air intake required to cool the coolant may be insufficient. At this time, it is necessary to reduce the amount of flue gas entering the waste heat recovery system, or turn on the electronic fan 10 to increase the air intake so that the organic working fluid can condense under a safe pressure.

[0134] The specific operation of working mode three can be: the first bypass valve 14 on the hot side of the flue gas heat exchanger 3 gradually increases its opening from a closed state, the second bypass valve 15 on the working medium inlet side of the expander 4 remains closed, the third bypass valve 16 at the coolant inlet of the air-cooled radiator 9 remains closed, and the electronic fan 10 is turned on.

[0135] 4. Working mode 4: The working mode when the vehicle's headwind cooling condition is excessive, that is, the headwind flow is too large or the engine is under low load;

[0136] Working mode 4 includes at least one of the following two working modes:

[0137] Working mode three: turning off the electronic fan 10;

[0138] Working mode 4: increase the opening size of the third bypass valve 16 at the coolant inlet of the air-cooled radiator 9; at the same time, the first bypass valve 14 on the hot side of the flue gas heat exchanger 3 remains closed (i.e., not bypassed), and the second bypass valve 15 on the working medium inlet side of the expander 4 remains closed (i.e., not bypassed);

[0139] It should be noted that working mode 3 or working mode 4 can be executed, or these two control strategies can be used in combination to maximize the net work output by the thermal management system coupled to the ORC.

[0140] It should be noted that when the engine (i.e., the internal combustion engine 6) is operating at a low load, the flue gas flow and temperature will be significantly lower than the design point; or when the air intake flow is sufficient, the air intake volume is sufficient to cool the coolant of the engine (i.e., the internal combustion engine 6). In order to prevent the temperature of the circulating coolant entering the internal combustion engine 6 from being too low and affecting the normal operation of the engine, it is necessary to bypass a portion of the coolant entering the air-cooled radiator 9, or turn off the electronic fan 10.

[0141] Specific operations of working mode four: the first bypass valve 14 on the hot side of the flue gas heat exchanger 3 remains closed, the second bypass valve 15 on the working medium inlet side of the expander 4 remains closed, the bypass valve 16 at the inlet of the air-cooled radiator gradually increases its opening from a closed state, and the electronic fan 10 is turned off.

[0142] In the present invention, in a specific implementation, the power output shaft of the expander 4 can be connected to the input shaft of a generator; the expander 4 can be used to drive the generator to generate electricity.

[0143] It should be noted that the device of the present invention can be used for both power generation and power output (i.e., outputting mechanical work to the outside through an expander).

[0144] Compared with the prior art, the on-board waste heat recovery organic Rankine cycle system and thermal management strategy using the internal combustion engine cylinder jacket water cooling medium provided by the present invention have the following beneficial effects:

[0145] 1. The waste heat recovery system and thermal management strategy proposed in the present invention realizes the effective recovery of medium and high temperature exhaust heat through the coordinated work of components such as working fluid pump, circulating cooling water pump, flue gas heat exchanger, condenser, air-cooled radiator and expander. The system realizes the stable and efficient utilization of medium and high temperature waste heat through different thermal management strategies in a wide range of internal combustion engine operating conditions, and ultimately solves the problem of the waste heat recovery system's stringent requirements on condensation conditions in vehicle-mounted application environments.

[0146] 2. The present invention improves the utilization efficiency of the primary energy of the internal combustion engine through a highly integrated system configuration design, which not only ensures the system's work capacity, but also reasonably realizes the conditions required for system condensation. In addition, it enhances the potential of the internal combustion engine waste heat recovery system in mobile vehicle applications, and can also alleviate the pressure of engine cold start under special ambient temperatures, which is of great significance for energy conservation and emission reduction in the internal combustion engine application industry.

[0147] 3. The present invention utilizes cyclopentane as a circulating working fluid to completely recover the heat of the flue gas of the internal combustion engine, so that the cold end of the cycle reaches a reasonable on-board condensation condition and realizes the miniaturization of the waste heat recovery system, as well as operational stability, to meet the actual needs in on-board applications, realize efficient thermal management of the automobile-ORC coupling system and improve overall energy utilization.

[0148] The above embodiments of the present invention are only preferred examples, which are intended to illustrate the implementation methods of the present invention, rather than to limit its concept and scope. Without departing from the design concept of the present invention, various modifications and improvements made by engineers and technicians in this field to the technical solution of the present invention (such as recycling a variety of waste heat sources of different grades; and changing the arrangement and position of core components) should fall within the scope of protection of the present invention.

[0149] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An on-vehicle waste heat recovery organic Rankine cycle system using internal combustion engine cylinder jacket water cooling medium, characterized in that: It comprises a working fluid storage tank (1), a working fluid pump (2), a flue gas heat exchanger (3), an expander (4), a condenser (5), an internal combustion engine (6), a cooling water pump (7), a coolant storage tank (8), an air-cooled radiator (9), a cylinder jacket water inlet (11) for the internal combustion engine, an exhaust port (12) for the internal combustion engine, a cylinder jacket water outlet (13) for the internal combustion engine, a first bypass valve (14), a second bypass valve (15) and a third bypass valve (16); The working fluid storage tank (1) stores organic working fluid in advance; A working fluid inlet of the working fluid pump (2) is connected to a working fluid outlet of the working fluid storage tank (1); The working fluid outlet of the working fluid pump (2) is connected to the working fluid channel inlet a of the flue gas heat exchanger (3); The heat exchange channel inlet c of the flue gas heat exchanger (3) is connected to the internal combustion engine exhaust port (12) on the internal combustion engine (6); The heat exchange channel outlet d of the flue gas heat exchanger (3) is connected to the external environment; The working medium channel outlet b of the flue gas heat exchanger (3) is respectively connected to the working medium inlet of the expander (4) and the working medium inlet a of the condenser (5); The working fluid outlet of the expander (4) is connected to the working fluid inlet a of the condenser (5); The working fluid outlet b of the condenser (5) is connected to the working fluid inlet of the working fluid storage tank (1); The coolant storage tank (8) stores the coolant in advance; The coolant outlet of the coolant storage tank (8) is connected to the coolant inlet of the cooling water pump (7); The coolant outlet of the cooling water pump (7) is connected to the internal combustion engine cylinder jacket water inlet (11) on the internal combustion engine (6) and the coolant inlet c of the condenser (5) respectively; The coolant outlet d of the condenser (5) is connected to the coolant inlet of the air-cooled radiator (9) and the coolant inlet of the coolant storage tank (8) respectively; The internal combustion engine cylinder jacket water outlet (13) on the internal combustion engine (6) is connected to the coolant inlet of the air-cooled radiator (9) and the coolant inlet of the coolant storage tank (8) respectively; The coolant outlet of the air-cooled radiator (9) is connected to the coolant inlet of the coolant storage tank (8); The internal combustion engine (6) has a coolant channel at both ends, which are a cylinder jacket water inlet (11) for the internal combustion engine and a cylinder jacket water outlet (13) for the internal combustion engine; At least one electronic fan (10) is arranged behind the air-cooling radiator (9).

2. The vehicle-mounted waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium as claimed in claim 1, characterized in that: The organic working fluid cyclopentane is used as the circulating working fluid.

3. The vehicle-mounted waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium as claimed in claim 1, characterized in that: A working fluid inlet of the working fluid storage tank (1) is located at the upper part of the tank body of the working fluid storage tank (1); The working fluid outlet of the working fluid storage tank (1) is located at the bottom of the tank body of the working fluid storage tank (1).

4. The vehicle-mounted waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium as claimed in claim 1, characterized in that: Also includes a first bypass valve (14); A first interface a of the first bypass valve (14) is connected to the external environment; The heat exchange channel inlet c of the flue gas heat exchanger (3) is connected to the second interface b of the first bypass valve (14); The third port c of the first bypass valve (14) is connected to the internal combustion engine exhaust port (12) on the internal combustion engine (6).

5. The vehicle-mounted waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium as claimed in claim 1, characterized in that: Also includes a second bypass valve (15); The working medium channel outlet b of the flue gas heat exchanger (3) is connected to the first interface a of the second bypass valve (15); The second interface b of the second bypass valve (15) is connected to the working medium inlet a of the condenser (5); The third port c of the second bypass valve (15) is connected to the working medium inlet of the expander (4).

6. The vehicle-mounted waste heat recovery organic Rankine cycle system using the internal combustion engine cylinder jacket water cooling medium as claimed in claim 1, characterized in that: Also includes a third bypass valve (16); A first interface a of the third bypass valve (16) is connected to a coolant inlet of a coolant storage tank (8); The second interface b of the third bypass valve (16) is connected to the coolant outlet d of the condenser (5) and the cylinder jacket water outlet (13) for the internal combustion engine on the internal combustion engine (6) respectively; The coolant inlet of the air-cooled radiator (9) is connected to the third interface c of the third bypass valve (16).

7. A thermal management strategy for an on-vehicle waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder jacket water cooling medium as claimed in any one of claims 1 to 6, characterized in that: It includes working mode 1: when the car is in a low temperature environment, the working mode of the car is cold started; Working mode 1, corresponding specific thermal management strategies are as follows: The first bypass valve (14) is closed so that the heat exchange channel inlet c of the flue gas heat exchanger (3) is connected to the internal combustion engine exhaust port (12) on the internal combustion engine (6); the second bypass valve (15) is opened so that the working medium channel outlet b of the flue gas heat exchanger (3) is not connected to the working medium inlet of the expansion machine (4), and the working medium directly enters the condenser (5); the third bypass valve (16) is opened so that the coolant at the outlet d of the condenser (5) and the coolant at the cylinder jacket water outlet (13) of the internal combustion engine are combined and flow into the inlet of the coolant storage tank (8); the electronic fan (10) remains closed; All high-temperature flue gas discharged from the internal combustion engine exhaust port (12) of the internal combustion engine (6) is passed into the heat exchange channel of the flue gas heat exchanger (3) to exchange heat with the organic working medium in the working medium channel of the flue gas heat exchanger (3). The organic working medium does not enter the expansion machine (4) to perform work, but is directly transported to the condenser (5). The coolant transported by the cooling water pump (7) is heated by the condenser (5). After passing through the third bypass valve (16), the coolant flows through the branch and returns to the coolant storage tank (8). The coolant does not pass through the air-cooled radiator (6) to dissipate heat, thereby achieving the purpose of indirectly heating the coolant with the exhaust gas. With the circulating organic working medium as the intermediate carrier, the heat is gradually transferred from the high-temperature exhaust gas to the coolant, so that the coolant quickly reaches a safe operating temperature range during the cold start stage of the automobile, effectively increasing the coolant temperature, reducing the wear during the cold start, and extending the engine life.

8. A thermal management strategy for an on-vehicle waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder jacket water cooling medium as claimed in any one of claims 1 to 6, characterized in that: It includes working mode 2: the working mode when the automobile and waste heat recovery organic Rankine cycle system transitions from the startup state to the normal working state; Working mode 2, as follows: The first bypass valve (14) on the hot side of the flue gas heat exchanger (3) remains closed, so that all exhaust gas discharged from the internal combustion engine exhaust port (12) of the internal combustion engine (6) enters the heat exchange channel of the flue gas heat exchanger (3) and exchanges heat with the organic working medium in the working medium channel of the flue gas heat exchanger (3), thereby heating the organic working medium; The second bypass valve (15) on the working medium inlet side of the expander (4) gradually reduces its opening from an open state to 0, so that all the gaseous organic working medium enters the expander (4) to perform work; The third bypass valve (16) at the coolant inlet of the air-cooled radiator (9) gradually reduces its opening from an open state to 0, and the electronic fan (10) remains closed; The exhaust steam of the working medium outputted by the organic working medium during expansion and work in the expander (4) enters the condenser (5) for condensation and then enters the working medium storage tank (1), and is then transported to the flue gas heat exchanger (3) by the working medium pump (2). The heated working medium enters the expander (4) for work, thereby completing the organic Rankine cycle. The coolant transported by the cooling water pump (7) is heated by the condenser (5). After the third bypass valve (16) at the coolant inlet of the air-cooled radiator (9) is closed, the coolant flows through the air-cooled radiator (9) to dissipate heat, and then returns to the condenser (5) and the cylinder body of the internal combustion engine (6) through the coolant storage tank (8), completing the coolant cycle.

9. A thermal management strategy for an on-vehicle waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder jacket water cooling medium as claimed in any one of claims 1 to 6, characterized in that: It includes working mode 3: working mode when the vehicle's headwind cooling condition is insufficient, that is, when the headwind flow is insufficient; Working mode three includes at least one of the following two working modes: Working mode 1: increasing the cooling air flow rate by turning on and adjusting the gear position of the electronic fan (10); Working mode 2: by opening and increasing the opening degree of the first bypass valve (14) on the hot side of the flue gas heat exchanger (3), part of the flue gas is bypassed to reduce the cooling load of the air-cooled radiator (9); at the same time, the second bypass valve (15) on the working medium inlet side of the expander (4) remains closed, and the third bypass valve (16) at the coolant inlet of the air-cooled radiator (9) remains closed.

10. A thermal management strategy for an on-vehicle waste heat recovery organic Rankine cycle system using an internal combustion engine cylinder jacket water cooling medium as claimed in any one of claims 1 to 6, characterized in that: It includes working mode 4: when the vehicle has excessive headwind cooling conditions, that is, when the headwind flow is too large or the engine is under low load; Working mode 4 includes at least one of the following two working modes: Working mode three: turning off the electronic fan (10); Working mode 4: increasing the opening size of the third bypass valve (16) at the coolant inlet of the air-cooled radiator (9); at the same time, the first bypass valve (14) on the hot side of the flue gas heat exchanger (3) remains closed, and the second bypass valve (15) on the working fluid inlet side of the expander (4) remains closed.

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