Heat pool and heat management system for realizing automobile exhaust waste heat recovery by utilizing fused salt heat transfer and heat conduction

Abstract

The invention relates to a heat pool and a heat management system for realizing automobile exhaust waste heat recovery by utilizing fused salt heat transfer and heat conduction. The hot pool comprises a tail gas flowing pipe, a heat conduction oil flowing pipe and a hot pool shell, and a phase-change material fused salt is contained in the hot pool shell. According to the heat pool, on the basis of two media, high-boiling-point heat conduction oil is used for replacing low-boiling-point refrigerants, fused salt media are added, mutual heat exchange of the three media is achieved, corrugated pipes are used for replacing common steel pipes, the problem that circulation of heat exchange media is interrupted due to indirect and random automobile exhaust emission is solved, integration of heat transfer and heat storage is achieved, and the service life of the heat pool is prolonged. The heat transfer and storage capacity is high. The system comprises an air conditioner loop module, an engine loop module, a heat pool heat release loop module, a battery loop module and two five-way valves. The system has various different application scenes, tail gas directly exchanges heat with heat conduction oil in the heat pool heat exchanger to achieve direct heat release, heat in the tail gas is stored in the phase change material, and heat storage and heat exchange are achieved when the system needs to be used.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile exhaust waste heat recovery, and in particular to a heat pool and a thermal management system that utilizes molten salt heat transfer and heat conduction to realize automobile exhaust waste heat recovery. Background Art

[0002] As people's living standards continue to improve, cars have gradually become an indispensable part of every household's life. While cars bring convenience to people's travel, they also bring a series of problems, such as energy waste and environmental pollution. The heat generated by fuel combustion is lost in various ways, resulting in low thermal efficiency of cars. Among them, automobile exhaust takes away a large part, accounting for about one-third of the total heat, and its temperature is as high as several hundred degrees Celsius. Therefore, automobile exhaust has a very high recycling value.

[0003] At present, there are endless methods and devices for recycling automobile exhaust gas, most of which are based on common heat exchangers to directly convert and utilize this part of heat. One of the important reasons for the serious loss of engine fuel energy is the waste of energy. During the operation of the engine, only about 30% of the total energy of fuel combustion is converted into useful work, and the remaining energy will be lost to the atmosphere. Among them, the energy dissipated during the cooling operation accounts for about 30%, and the energy lost during the exhaust emission process is as high as 35%. Therefore, effectively recycling and utilizing the waste heat energy in the exhaust gas can greatly improve energy utilization and reduce fuel consumption.

[0004] Existing technologies for treating and recycling waste heat from automobile exhaust mainly focus on improving energy efficiency and reducing environmental pollution. The following are several common treatment and recycling methods:

[0005] (1) Thermoelectric power generation technology

[0006] Thermoelectric power generation technology is a technology that uses thermoelectric materials to directly convert thermal energy into electrical energy, relying on the Seebeck effect to achieve energy conversion. Unlike traditional thermodynamic power generation systems, thermoelectric power generation has the advantages of no moving parts, simple structure, and high reliability. The core of thermoelectric power generation is the Seebeck effect of thermoelectric materials. When there is a temperature difference between the two ends of a thermoelectric material, the electrons or holes inside the material move in a directional manner under the action of the thermal gradient, forming an electric potential difference, and finally outputting electrical energy. The basic working process of thermoelectric power generation technology includes: temperature difference generation, heat sources (such as exhaust gas, engine parts, industrial waste heat) provide heat on one side of the thermoelectric module, while the other side maintains a lower temperature to form a temperature difference. Directed movement of electrons / holes, due to the existence of thermal gradients, electrons or holes gain energy on the high temperature side and move to the low temperature side, generating an electromotive force. Current generation, voltage is generated at both ends of the thermoelectric material, and current is formed after connecting to an external circuit, outputting electrical energy.

[0007] (2) Organic Rankine cycle

[0008] The organic Rankine cycle system is a technology that uses low-temperature heat sources (such as waste heat, geothermal heat, or solar energy) to generate electricity. It is used to recover and utilize low-grade thermal energy in industry, transportation, and nature. The organic Rankine cycle system is based on the working principle of the classic Rankine cycle, but uses low-boiling-point organic working fluids (such as Freon, isobutane, or silicone oil) instead of water vapor to adapt to low-temperature and medium-temperature heat source conditions and improve system energy efficiency. The organic Rankine cycle is similar to the traditional steam Rankine cycle. Both use the phase change of the working fluid to achieve the conversion of thermal energy into mechanical energy, and then convert mechanical energy into electrical energy. However, the working fluid selected in the organic Rankine cycle system has a lower boiling point and can evaporate at a lower temperature and drive a turbine, which is particularly suitable for the utilization of low-grade heat sources.

[0009] The existing automobile exhaust waste heat treatment and recycling technologies have the following shortcomings: First, low efficiency: many traditional heat exchangers have low efficiency in the heat exchange process and cannot fully recover the exhaust waste heat. Second, large size: some designs are bulky, which increases the overall weight of the car and affects vehicle performance. Third, insufficient durability: some materials are prone to aging in high temperature and corrosive environments, resulting in a short life of the heat exchanger. Fourth, complex installation: installation and maintenance are relatively cumbersome, increasing manufacturing and maintenance costs. The introduction of an exhaust gas recovery system will increase system complexity and occupied space, may bring more maintenance costs, and increase manufacturing costs. Some exhaust gas waste heat recovery devices are large in size and are not suitable for light vehicles with limited space, especially difficult to integrate in small vehicles.

[0010] The exhaust heat recovery heat exchanger is an important component of the automobile exhaust heat recovery and utilization system. At present, the existing exhaust heat recovery heat exchanger system has the following shortcomings: First, most of them are heat exchangers for heat exchange between exhaust gas and refrigerant. Due to the high intensity, indirectness, randomness and mobility of automobile exhaust emissions, the heat exchanger system for heat exchange between the two media will be affected by cycle interruption. Moreover, since the boiling point of the refrigerant is much lower than that of the heat transfer oil, it will affect the pipeline air pressure after vaporization, resulting in system instability and low heat exchange efficiency; second, the existing heat storage heat exchanger is separated from the heat transfer heat exchanger, with poor heat storage and heat transfer capacity, strong heat dissipation capacity, and small heat capacity, resulting in the inability to guarantee heat supply under large load conditions. In addition, for electric vehicles, in extreme weather conditions, electric vehicles need to turn on PTC to maintain a comfortable temperature in the cabin and keep the engine and battery in their appropriate operating temperature range. The energy consumption of PTC accounts for about 30% of the energy consumption of the cabin, which greatly reduces the range of electric vehicles in high and low temperature environments.

[0011] Therefore, in order to solve the deficiencies in the prior art, there is an urgent need to realize a heat pool and thermal management system that utilizes molten salt heat transfer and heat conduction to recover automobile exhaust waste heat. Summary of the invention

[0012] The purpose of the present invention is to provide a heat pool and a thermal management system for recovering waste heat from automobile exhaust by utilizing molten salt heat transfer and heat conduction. The heat pool and the thermal management system for recovering waste heat from automobile exhaust by utilizing molten salt heat transfer and heat conduction can solve the deficiencies in the prior art, fully recover the waste heat from engine exhaust, and have a variety of application scenarios such as heating the cabin, engine, and battery. It can solve the shortcomings of traditional PTC, such as high energy consumption, poor heat transfer and storage capacity, strong heat dissipation capacity, and small heat capacity of traditional heat exchangers.

[0013] To achieve the above object, the present invention adopts the following technical solutions:

[0014] A heat pool for recovering waste heat from automobile exhaust gas by using molten salt for heat transfer and conduction, the heat pool comprising a heat pool shell and a plurality of exhaust gas flow pipes and heat transfer oil flow pipes installed in the heat pool shell; the plurality of exhaust gas flow pipes are parallel to each other; the heat transfer oil flow pipe comprises a first pipeline and a second pipeline connected in sequence; the first pipeline is wound around the outside of the plurality of exhaust gas flow pipes, and the second pipeline is located inside the exhaust gas flow pipes; the first pipeline is used for heat exchange between heat transfer oil and molten salt of phase change material; the second pipeline is used for heat exchange between heat transfer oil and automobile exhaust gas; molten salt of phase change material is contained in the heat pool shell; the exhaust gas flow pipe and the first pipeline are both in contact with the molten salt of phase change material.

[0015] As a further improvement of the above technical solution, the heat pool shell includes a shell body and a first end cover and a second end cover respectively arranged at the openings at both ends of the shell body; the shell body, the first end cover and the second end cover form a cavity; the first end cover is provided with an automobile exhaust inlet flange; the second end cover is provided with an automobile exhaust outlet flange; a through hole is provided above the shell body; a third end cover is installed at the through hole; the third end cover is used to seal the through hole; the first end cover is connected to the automobile exhaust pipe, the automobile exhaust pipe is installed on the first end cover, and is connected to the exhaust gas flow pipe; the automobile exhaust enters the multiple exhaust gas flow pipes through the automobile exhaust pipe and flows.

[0016] As a further improvement of the above technical solution, the heat transfer oil flow pipe is filled with heat transfer oil, and the heat transfer oil is 350# fully synthetic heat transfer oil; the heat transfer oil flow pipe is provided with a heat transfer oil inlet and a heat transfer oil outlet; the heat transfer oil inlet is used to replenish the heat transfer oil in the heat transfer oil flow pipe; the heat transfer oil outlet is used to discharge the heat transfer oil; the heat transfer oil in the heat transfer oil flow pipe absorbs the heat of automobile exhaust gas and is discharged through the heat transfer oil outlet, the heat generated by the exhaust gas in the exhaust gas flow pipe is recovered through the phase change material molten salt in the heat pool shell and the heat transfer oil in the heat transfer oil flow pipe, and the exhaust gas is discharged into the atmosphere through the automobile exhaust gas outlet flange.

[0017] As a further improvement of the above technical solution, the exhaust gas flow pipe adopts a 316 stainless steel pipe with an inner diameter of 26 mm and a wall thickness of 2 mm; the number of the exhaust gas flow pipes is 7; a tube sheet is arranged in the heat pool shell; the exhaust gas flow pipe is welded to the tube sheet.

[0018] As a further improvement of the above technical solution, the first pipeline and the second pipeline are connected and sealed by a steel pipe and a ferrule joint; the heat transfer oil flow pipe adopts a bellows, and the wall thickness of the bellows is 2.25mm and the inner diameter is 10mm.

[0019] As a further improvement of the above technical solution, the phase change material molten salt is a mixture obtained by mixing sodium nitrate and potassium nitrate in a mass ratio of 6:4.

[0020] As a further improvement of the above technical solution, the outer side of the heat pool shell is wrapped with an insulation layer, and the insulation layer is used to reduce heat loss; the insulation layer adopts insulation cotton.

[0021] The present invention also includes a thermal management system implemented by using the above-mentioned heat pool that utilizes molten salt heat transfer and heat conduction to recover waste heat from automobile exhaust, the system comprising: an air conditioning circuit module, an engine circuit module, a heat pool heat release circuit module, a battery circuit module, a first five-way valve and a second five-way valve.

[0022] The air conditioning circuit module includes a compressor, a condenser, a first expansion valve, an evaporator, a second water pump, a positive temperature coefficient thermistor PTC and a heater core; the engine circuit module includes a radiator, a fan, an engine and a first water pump; the heat pool heat release circuit module includes a heat pool, a liquid storage tank, a three-way valve, an oil pump and a first heat exchanger; the battery circuit module includes a third water pump, a battery and a second heat exchanger.

[0023] The outlet of the compressor is connected to the inlet of the condenser, the outlet of the condenser is connected to the inlet of the first expansion valve, the outlet of the first expansion valve is connected to the inlet of the evaporator, the outlet one of the second heat exchanger is connected to the port a of the first five-way valve, the inlet one of the second heat exchanger is connected to the port b of the first five-way valve, the outlet two of the second heat exchanger is connected to the inlet of the compressor and the outlet of the evaporator, and the outlet three of the second heat exchanger is connected to the inlet of the third water pump; the outlet of the evaporator is connected to the inlet of the compressor, forming a refrigeration circuit for an automobile air conditioner.

[0024] The outlet of the first water pump is connected to the inlet of the coolant circuit of the engine, the outlet of the coolant circuit of the engine is connected to the e port of the second five-way valve, the b port of the second five-way valve is connected to the d port of the first five-way valve, and the e port of the first five-way valve is connected to the inlet of the first water pump, forming a small circulation loop of the engine coolant.

[0025] The d port of the second five-way valve is connected to the inlet of the radiator, and the outlet of the radiator is connected to the inlet of the first water pump, forming a large circulation loop of the engine coolant. The exhaust outlet of the engine is connected to the exhaust inlet of the heat pool, the exhaust outlet of the heat pool is connected to the exhaust pipe, the heat transfer oil outlet of the heat pool is connected to the inlet 1 of the liquid storage tank, the outlet of the liquid storage tank is connected to the inlet of the oil pump, the outlet of the oil pump is connected to the port 1 of the three-way valve, the port 2 of the three-way valve is connected to the heat transfer oil inlet of the heat pool, and the port 3 of the three-way valve is connected to the inlet 2 of the liquid storage tank, forming a heat transfer oil loop.

[0026] The first heat exchanger is connected to port a of the second five-way valve, port c of the second five-way valve is connected to the inlet of the second water pump, the outlet of the second water pump is connected to the inlet of the PTC, the outlet of the PTC is connected to the inlet of the heater core, the outlet of the heater core is connected to port c of the first five-way valve, port b of the first five-way valve is connected to port d of the second five-way valve, forming a cabin heating circuit.

[0027] The outlet of the condenser is connected to the inlet of the second expansion valve, the outlet of the second expansion valve is connected to the inlet of the second heat exchanger, and the outlet of the second expansion valve is connected to the inlet of the second heat exchanger, forming an air conditioning cooling battery pack circuit.

[0028] The outlet of the third water pump is connected to the inlet of the battery internal coolant circuit, the outlet of the battery internal coolant circuit is connected to the inlet of the second heat exchanger, and the outlet of the second heat exchanger is connected to the inlet of the third water pump, forming a battery internal coolant circuit.

[0029] As a further improvement of the above technical solution, the operating modes of the thermal management system include PTC cabin and battery heating mode, hot pool and PTC cabin and battery heating mode in pure electric state, hot pool engine heating mode and engine heat dissipation and hot pool cabin and battery heating mode in extended-range state.

[0030] In the pure electric state, in the PTC heated cabin and battery mode, the outlet of the second water pump is connected to the inlet of the PTC, the outlet of the PTC is connected to the inlet of the heater core, the outlet of the heater core is connected to the c port of the first five-way valve, the b port of the first five-way valve is connected to the inlet one of the second heat exchanger, the outlet one of the second heat exchanger is connected to the a port of the first five-way valve, the d port of the first five-way valve is connected to the b port of the second five-way valve, and the c port of the second five-way valve is connected to the inlet of the second water pump.

[0031] In the pure electric state, in the heat pool and PTC heating cabin and battery mode, the outlet of the heat pool is connected to the inlet of the liquid storage tank, the outlet of the liquid storage tank is connected to the inlet of the first heat exchanger, the outlet of the first heat exchanger is connected to the inlet of the oil pump, the outlet of the oil pump is connected to the inlet of the heat pool, and a three-way valve is arranged between the outlet of the oil pump and the inlet of the heat pool; the outlet of the second water pump is connected to the inlet of the PTC, the outlet of the PTC is connected to the inlet of the heater core, the outlet of the heater core is connected to the c port of the first five-way valve, the b port of the first five-way valve is connected to the inlet one of the second heat exchanger, the outlet one of the second heat exchanger is connected to the a port of the first five-way valve, the d port of the first five-way valve is connected to the b port of the second five-way valve, and the a port of the second five-way valve is connected to the inlet of the first heat exchanger; the outlet of the third water pump is connected to the inlet of the cooling circuit of the battery, the outlet of the cooling circuit of the battery is connected to the inlet three of the second heat exchanger, and the outlet three of the second heat exchanger is connected to the inlet of the third water pump.

[0032] In the heat pool heating engine mode under extended range thermal management, the outlet of the oil pump is connected to port 1 of the three-way valve, port 2 of the three-way valve is connected to the oil circuit inlet of the heat pool, port 3 of the three-way valve is connected to inlet 2 of the liquid storage tank, the oil circuit outlet of the heat pool is connected to the inlet of the liquid storage tank, the outlet of the liquid storage tank is connected to the inlet of the first heat exchanger, and the outlet of the first heat exchanger is connected to the inlet of the oil pump; the outlet of the coolant circuit of the engine is connected to port e of the second five-way valve, port a of the second five-way valve is connected to the inlet of the first heat exchanger, the outlet of the first heat exchanger is connected to port c of the second five-way valve, port b of the second five-way valve is connected to port d of the first five-way valve, port e of the first five-way valve is connected to the inlet of the first water pump, and the outlet of the first water pump is connected to the inlet of the coolant circuit of the engine.

[0033] In the engine heat dissipation and heat pool cabin heating and battery mode under the extended range thermal management, the outlet of the engine coolant circuit is connected to the e port of the second five-way valve, the d port of the second five-way valve is connected to the inlet of the radiator, the outlet of the radiator is connected to the inlet of the first water pump, and the outlet of the first water pump is connected to the inlet of the engine coolant circuit; the outlet of the oil pump is connected to the port 1 of the three-way valve, the port 2 of the three-way valve is connected to the oil circuit inlet of the heat pool, the oil circuit outlet of the heat pool is connected to the inlet of the liquid storage tank, and the outlet of the liquid storage tank is connected to the inlet of the first heat exchanger, The outlet of the first heat exchanger is connected to the inlet of the oil pump; the outlet of the second water pump is connected to the inlet of the PTC, the outlet of the PTC is connected to the inlet of the heater core, the outlet of the heater core is connected to the c port of the first five-way valve, the b port of the first five-way valve is connected to the inlet one of the second heat exchanger, the outlet one of the second heat exchanger is connected to the a port of the first five-way valve, the d port of the first five-way valve is connected to the b port of the second five-way valve, the a port of the second five-way valve is connected to the inlet of the first heat exchanger, and the outlet of the first heat exchanger is connected to the inlet of the second water pump.

[0034] As a further improvement of the above technical solution, the working method of the thermal management system includes the following steps:

[0035] The operating modes of the thermal management system include PTC cabin and battery heating mode, hot pool and PTC cabin and battery heating mode in pure electric state, hot pool engine heating mode and engine heat dissipation and hot pool cabin and battery heating mode in extended-range state.

[0036] S1, PTC heating cabin and battery mode in pure electric state

[0037] The coolant flows out from the first water pump and flows through the PTC. At this time, the PTC is in the open state, the coolant temperature rises, and then flows into the heater core. The heat in the heater core is blown into the cabin by the fan, and the temperature in the cabin is increased. Then, after the coolant flows out from the heater core, it flows into the c port of the first five-way valve, and then flows from the c port of the first five-way valve to the b port of the first five-way valve, and then flows from the b port of the first five-way valve to the inlet 1 of the second heat exchanger, and flows from the outlet 1 of the second heat exchanger to the a port of the first five-way valve, and then flows from the b port of the first five-way valve to the inlet 1 of the second heat exchanger. The a port of the first five-way valve flows to the d port of the first five-way valve, flows from the d port of the first five-way valve to the b port of the second five-way valve, flows from the b port of the second five-way valve to the c port of the second five-way valve, and finally returns to the second water pump to form a circulation loop; wherein, the coolant in the coolant loop of the battery and the coolant in the coolant loop of the PTC perform heat exchange in the second heat exchanger, the temperature of the coolant in the coolant loop of the battery is increased, and it flows through the third water pump, the battery, and the second heat exchanger in sequence, bringing heat into the battery to heat the battery.

[0038] S2: Heat pool and PTC heated cabin and battery mode in pure electric state

[0039] The heat transfer oil flows out from the oil pump, flows through the three-way valve, and then flows into the heat transfer oil flow pipe in the heat pool, then flows through the liquid storage tank and the first heat exchanger in sequence, and finally returns to the oil pump to form a circulation loop; in the cooling liquid loop of the heater core, the cooling liquid flows out from the second water pump, passes through the PTC, the heater core, the passage between the c port and the b port of the first five-way valve, the second heat exchanger, the passage between the a port and the d port of the first five-way valve, the passage between the b port and the a port of the second five-way valve, the first heat exchanger, and finally returns to the second water pump to form a circulation loop; in the cooling liquid loop of the battery, the cooling liquid flows out from the third water pump, flows through the inside of the battery, the second heat exchanger in sequence, and finally returns to the third water pump to form a circulation loop; wherein, the heat transfer oil in the heat transfer oil loop of the heat pool and the cooling liquid in the cooling liquid loop of the heater core perform heat exchange in the first heat exchanger, and the cooling liquid in the cooling liquid loop of the heater core and the cooling liquid in the cooling liquid loop of the battery perform heat exchange in the second heat exchanger, bringing heat into the heater core and the inside of the battery.

[0040] S3, thermal pool heating engine mode under extended range thermal management

[0041] The heat transfer oil flows out from the oil pump, flows through the three-way valve, and then flows into the heat transfer oil flow pipe of the heat pool, then flows through the liquid storage tank and the first heat exchanger in sequence, and finally returns to the oil pump to form a circulation loop; in the coolant loop of the engine, the coolant flows out from the first water pump, flows through the engine, the e port of the second five-way valve, the a port of the second five-way valve, the first heat exchanger, the c port of the second five-way valve, the b port of the second five-way valve, the d port of the first five-way valve, the e port of the first five-way valve, and finally returns to the first water pump to form a circulation loop; wherein, the heat transfer oil in the heat transfer oil loop of the heat pool and the coolant in the coolant loop of the engine perform heat exchange in the first heat exchanger, and transfers heat to the coolant in the coolant loop of the engine, which is used for rapid heating of the engine during cold start.

[0042] S4, engine cooling and hot pool cabin heating under extended range thermal management, battery mode

[0043] The heat transfer oil flows out from the oil pump, flows through the three-way valve, and then flows into the heat transfer oil flow pipe of the heat pool, then flows through the liquid storage tank and the first heat exchanger in turn, and finally returns to the oil pump to form a circulation loop; in the coolant loop of the heater core, the coolant flows out from the second water pump, passes through the PTC and the heater core in turn, flows through the c port of the first five-way valve, flows to the b port of the first five-way valve, flows to the inlet 1 of the second heat exchanger, flows from the outlet 1 of the second heat exchanger to the a port of the first five-way valve, flows out from the d port of the first five-way valve to the b port of the second five-way valve, flows out from the a port of the second five-way valve to The inlet of the first heat exchanger flows out from the outlet of the first heat exchanger to the inlet of the second water pump to form a circulation loop; in the engine's large circulation cooling loop, the coolant flows out from the first water pump, flows through the engine in sequence, flows to the e port of the second five-way valve, flows out from the d port of the second five-way valve to the radiator inlet, and flows from the radiator outlet to the inlet of the first water pump to form a circulation loop; the heat transfer oil in the heat transfer oil circuit of the heat pool and the coolant in the coolant circuit of the heater core perform heat exchange in the first heat exchanger, bringing heat into the heater core and bringing heat out from the inside of the engine to the outside.

[0044] Compared with the prior art, the advantages of the present invention are:

[0045] (1) The present invention can be widely used in exhaust waste heat treatment of hybrid and extended-range vehicles. The automobile exhaust waste heat recovery and utilization system described in the present invention integrates a heat pool thermal management system using a five-way valve, which can efficiently manage the flow path of the loop fluid and simplify the arrangement and design of the system loop. The automobile exhaust waste heat recovery and utilization system described in the present invention realizes waste heat recovery and reuse of multiple heat energies. The heat pool transfers the heat energy in the exhaust gas to the cooling medium by contacting with the high-temperature exhaust gas, thereby reducing the temperature of the exhaust gas and recovering its heat for other purposes. For example, it provides a heat source for heating or air conditioning in the car, converts heat energy into electrical energy through a thermoelectric conversion device, and is used to preheat engine components during cold start, thereby reducing energy loss during start-up. The automobile exhaust waste heat recovery and utilization system described in the present invention can reduce environmental pollution. After the exhaust temperature is reduced, it helps to reduce the generation of some pollutants (such as nitrogen oxides), while reducing the exhaust gas emission heat and reducing thermal pollution to the environment.

[0046] (2) In order to solve the problems of low heat exchange efficiency and poor heat storage capacity caused by the indirectness and randomness of automobile exhaust gas that existing waste heat recovery heat exchangers cannot overcome, the present invention designs an energy-saving molten salt heat transfer and heat storage heat exchanger that integrates heat collection and heat storage, fully utilizes the waste heat of motor vehicle exhaust, reduces energy consumption, and provides an auxiliary heat source for the vehicle. The present invention can solve the problem of heat transfer medium circulation interruption caused by indirect and random emissions of motor vehicle exhaust gas, has a high heat storage capacity, and adopts a bellows structure to achieve miniaturization of the overall structure, providing technical support for the development and application of molten salt heat storage technology. The present invention realizes an integrated design of heat exchange and heat storage, greatly improves the heat exchange efficiency of the heat exchanger, and reduces heat loss in the heat exchange path. In addition, the present invention can replace PTC to provide heat for the cabin, battery, and engine, saving energy consumption of electric vehicles.

[0047] (3) The heat exchanger described in the present invention contains molten salt of phase change material. The molten salt has the characteristics of large heat capacity and excellent heat storage performance, which makes the present invention have the dual effects of heat transfer and heat storage, and overcomes the problem of interruption of automobile exhaust waste heat recovery cycle caused by the low boiling point of the refrigerant, large pressure change after gasification, and high intensity, indirectness and randomness of automobile exhaust emission in the traditional heat exchanger for heat exchange between automobile exhaust and refrigerant. By using molten salt, the present invention can adjust the instability of heat absorption of heat transfer oil, avoid the phenomenon of uneven temperature distribution, and improve stability. At the same time, it also overcomes the shortcomings of existing heat storage heat exchangers, such as poor heat storage capacity of heat storage medium, strong heat dissipation capacity, small heat capacity, and inability to guarantee heat supply under large heat load conditions.

[0048] (4) The present invention divides the heat transfer oil flow pipe into two sections, namely the first pipeline and the second pipeline. The first pipeline is used for heat exchange between the heat transfer oil and the phase change material molten salt; the second pipeline is used for heat exchange between the heat transfer oil and the automobile exhaust gas, thus realizing the function that the heat transfer oil, the exhaust gas and the phase change material can exchange heat with each other. The present invention solves the problem of low heat transfer and heat storage efficiency caused by the separate operation of heat transfer and heat storage in the traditional heat exchanger, integrates heat transfer and heat storage, reduces the path of the heat transfer process, and reduces heat loss. Through the structural design of the heat transfer oil flow pipe, direct heat exchange between the heat transfer oil flow pipe and the molten salt in the heat pool shell, the heat transfer oil flow pipe and the exhaust gas flow pipe, and the exhaust gas flow pipe and the molten salt in the heat pool shell is realized, thereby improving the heat exchange efficiency of the heat transfer oil, and being able to provide heat efficiently when the cabin, battery and engine are in urgent need of heat. Moreover, the phase change material molten salt directly exchanges heat with the heat transfer oil and the exhaust gas, and can store the remaining heat in the molten salt for subsequent use.

[0049] (5) The present invention solves the problem that the driving range of traditional hybrid vehicles is greatly reduced due to the use of PTC heating in severe cold weather. The integrated heat pool can replace PTC and provide heat to the cabin, battery, and engine. The existing exhaust waste heat recovery devices generally only have heat transfer functions, and the heat storage function is realized by other devices, which greatly lengthens the heat transfer and storage path and causes serious heat loss. The integrated heat transfer and storage design realized by the heat pool adopted in the present invention can solve this problem well and can effectively save space. Moreover, hybrid vehicles in the automotive field still generally use PTC to heat the required parts in the car, and the present invention can effectively replace the automobile PTC, thereby saving energy consumption. The present invention has a variety of different application scenarios, such as providing heat to the cabin, battery, and engine, and the exhaust gas directly exchanges heat with the heat transfer oil in the heat pool to achieve direct heat release. The heat in the exhaust gas is stored in the phase change material and used when needed to achieve heat storage and heat exchange. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic diagram of the thermal management system of the present invention;

[0051] Figure 2 This is a schematic diagram of the thermal management system that uses PTC to heat the battery / cabin in pure electric mode;

[0052] Figure 3 It is a schematic diagram of the thermal management system that uses a heat pool / heat pool + PTC to heat the engine / cabin / battery in the extended range state;

[0053] Figure 4 It is a schematic diagram of the thermal management system that uses a heat pool / heat pool + PTC to heat the engine / cabin / battery in the extended range state;

[0054] Figure 5This is the schematic diagram of the thermal management system for engine cooling + heat pool heating cabin / battery in the extended range state;

[0055] Figure 6 is a longitudinal cross-sectional view of the heat pool of the present invention;

[0056] Figure 7 is a cross-sectional view of a heat pool in the present invention;

[0057] Figure 8 It is the internal structure diagram of the heat pool in the present invention;

[0058] Fig. 9 is a front view of the heat pool in the present invention;

[0059] Fig.10 It is a left side view of the heat pool in the present invention.

[0060] in:

[0061] 1. Automobile exhaust inlet flange, 2. First end cover, 3. Tube sheet, 4. Compression fitting, 5. Heat transfer oil flow pipe, 6. Exhaust flow pipe, 7. Shell body, 8. Second end cover, 9. Automobile exhaust outlet flange, 10. Heat transfer oil inlet, 11. Heat transfer oil outlet, 12. Through hole, 13. Third end cover, 14. Compressor, 15. Condenser, 16. First expansion valve, 17. Evaporator, 18. Radiator, 19. Second five-way valve, 20. Second water pump, 21. PTC, 22. Warm air core, 23. First five-way valve, 24. First water pump, 25. Engine, 26. Fan, 27. First heat exchanger, 28. Heat pool, 29. Liquid storage tank, 30. Oil pump, 31. Three-way valve, 32. Exhaust pipe, 33. Second expansion valve, 34. Second heat exchanger, 35. Battery, 36. Third water pump. DETAILED DESCRIPTION

[0062] The present invention will be further described below in conjunction with the accompanying drawings:

[0063] like Figure 1 The thermal management system shown includes an air conditioning circuit module, an engine circuit module, a heat pool heat release circuit module, a battery circuit module, a first five-way valve 23 and a second five-way valve 19 .

[0064] In the thermal management system, the outlet of the compressor 14 is connected to the inlet of the condenser 15, the outlet of the condenser 15 is connected to the first expansion valve 16, the first expansion valve 16 is connected to the inlet of the evaporator 17, the second expansion valve 33 is connected to the second heat exchanger 34, and the outlet of the evaporator 17 is connected to the inlet of the compressor 14, forming a car air conditioning refrigeration circuit. The outlet of the first water pump 24 is connected to the inlet of the coolant circuit of the engine 25, the outlet of the coolant circuit of the engine 25 is connected to the second five-way valve 19, the second five-way valve 19 is connected to the first five-way valve 23, the first five-way valve 23 is connected to the inlet of the first water pump 24, forming a small circulation loop of the engine coolant, the second five-way valve 19 is connected to the radiator 18, the radiator 18 is connected to the inlet of the first water pump 24, forming a large circulation loop of the engine coolant. The exhaust outlet of the engine 25 is connected to the exhaust inlet of the heat pool 35, the exhaust outlet of the heat pool 35 is connected to the exhaust pipe 32, the heat transfer oil outlet of the heat pool 35 is connected to the liquid storage tank 29, the liquid storage tank 29 is connected to the inlet of the oil pump 30, the outlet of the oil pump 30 is connected to the three-way valve, and the three-way valve is connected to the heat transfer oil inlet of the heat pool, forming a heat transfer oil circuit. The first heat exchanger is connected to the second five-way valve, the second five-way valve 19 is connected to the second water pump 20, the second water pump 20 is connected to the PTC 21, the PTC 21 is connected to the heater core 22, the heater core 22 is connected to the first five-way valve 23, and the first five-way valve 23 is connected to the second five-way valve 19, forming a cabin heating circuit. The second expansion valve 33 is connected to the condenser 15 and the second heat exchanger 34, forming an air conditioning cooling battery pack circuit. The outlet of the third water pump 36 is connected to the inlet of the coolant circuit inside the battery 35, the coolant outlet of the battery 25 is connected to the second heat exchanger 34, and the second heat exchanger 34 is connected to the inlet of the third water pump 36, forming a battery cooling circuit. Figure 1 As shown, the ports at the upper end of the second heat exchanger 34 are outlet 1, outlet 2 and inlet 3 from left to right; the ports at the lower end of the second heat exchanger 34 are inlet 1, inlet 2 and outlet 3 from left to right.

[0065] The air conditioning circuit module includes a compressor 14, a condenser 15, a first expansion valve 16, an evaporator 17, a first water pump 24, a PTC 21, and a heater core 22. The engine circuit module includes a radiator 18, a fan 26, an engine 25, and a second water pump 20. The heat pool heat release circuit module includes a heat pool 28, a liquid storage tank 29, a three-way valve 31, an oil pump 30, and a first heat exchanger 27. The battery circuit module includes a third water pump 36, a battery 35, and a second heat exchanger 34.

[0066] In the above thermal management system, the compressor 14 is used to compress the low-pressure and low-temperature refrigerant gas to turn it into a high-pressure and high-temperature gas, and promote the circulation of the refrigerant in the system. The condenser 15 is used to cool and liquefy the high-pressure and high-temperature refrigerant gas discharged from the compressor into a high-pressure liquid, while releasing heat. The evaporator 17 is used for the low-pressure liquid refrigerant to absorb heat and evaporate in the evaporator to generate cold to reduce the temperature inside the vehicle. The heater core 22 is used when heating is required, and the engine coolant flows through the heater core to transfer heat to the air, which is used to increase the temperature inside the vehicle. The first five-way valve 23 and the second five-way valve 19 are used to adjust the direction of the refrigerant flow to achieve the switching of the cooling and heating functions. The first water pump 24, the second water pump 20 and the third water pump 36 are used to drive the coolant to circulate in the cooling circuit to take away the heat from the heat source. The PTC 21 is used to assist in providing the heating function, usually heating the air inside the vehicle when the internal combustion engine coolant does not reach a sufficient temperature. The first expansion valve 16 and the second expansion valve 33 are used to reduce the pressure and temperature of the refrigerant, control its flow into the evaporator, and adjust the evaporation efficiency. The first heat exchanger and the second heat exchanger are used to achieve heat exchange between the coolant and other media (such as air or another liquid) to ensure efficient heat dissipation or heating of the system. The heat pool 28 is used to recover waste heat and realize multiple thermal energy utilization. The heat pool 28 contacts the high-temperature exhaust gas, transfers the heat energy in the exhaust gas to the cooling medium, reduces the temperature of the exhaust gas, and recovers its heat for other purposes. For example, it provides a heat source for heating or air conditioning in the car, converts heat energy into electrical energy through thermoelectric conversion equipment, and is used to preheat engine components during cold start, reducing energy loss during start-up. On the other hand, it is used to reduce environmental pollution. After the exhaust gas temperature is reduced, it helps to reduce the generation of some pollutants (such as nitrogen oxides), while reducing the exhaust gas emission heat and reducing thermal pollution to the environment.

[0067] In order to solve the deficiencies in the prior art, the present invention adopts a heat pool in the thermal management system of new energy vehicles. The heat pool replaces the low-boiling-point refrigerant with high-boiling-point heat transfer oil on the basis of the two media, and adds molten salt medium to achieve heat exchange between the three media. Corrugated pipes are used instead of ordinary steel pipes, which overcomes the problem of heat exchange medium circulation interruption caused by the indirect and random nature of automobile exhaust emissions, and has the characteristics of strong heat transfer and heat storage capacity.

[0068] The thermal management system described above adopts Figure 6~Figure 10 The heat pool shown is implemented, and the heat pool includes a heat pool shell and a plurality of exhaust gas flow pipes 6 and heat transfer oil flow pipes 5 arranged in the heat pool shell.

[0069] like Figure 6As shown, the heat pool shell includes a shell body 7 and a first end cover 2 and a second end cover 8 arranged at the openings at both ends of the shell body 7. The shell body, the first end cover and the second end cover form a cavity. The first end cover 2 is connected to the automobile exhaust pipe, and the automobile exhaust pipe is installed on the first end cover 2 and is connected to the exhaust gas flow pipe 6; the automobile exhaust enters the multiple exhaust gas flow pipes 6 through the automobile exhaust pipe. The heat pool shell contains a phase change material molten salt. The phase change material molten salt is a mixture obtained by mixing sodium nitrate and potassium nitrate in a mass ratio of 6:4. In this embodiment, the overall length of the heat exchanger is 502.5 mm, the width is 160 mm, and the height is 160 mm.

[0070] After the exhaust gas is introduced, the exhaust gas and the phase change material molten salt wrapped on the automobile exhaust gas flow pipe 6 undergo sufficient heat exchange. After the molten salt absorbs heat, a phase change occurs, from a solid state to a molten state. The heat transfer oil flowing from the liquid storage tank into the heat transfer oil inlet 10 and the molten salt absorb part of the heat by natural convection conduction. Then, in the second pipeline, the heat transfer oil and the exhaust gas undergo sufficient heat exchange, so that the speed at which the temperature of the heat transfer oil rises can be guaranteed. The heat transfer oil in the heat transfer oil flow pipe 5 absorbs the heat of the automobile exhaust gas and is discharged through the heat transfer oil outlet 44. After the heat generated by the exhaust gas in the exhaust gas flow pipe 6 is recovered by the phase change material molten salt in the heat pool shell and the heat transfer oil in the heat transfer oil flow pipe 5, the exhaust gas is discharged into the atmosphere through the automobile exhaust gas outlet flange.

[0071] Furthermore, the multiple exhaust gas flow pipes 6 are parallel to each other and fixed in a cavity surrounded by the first end cover 2, the second end cover 8, and the shell body 7. The heat transfer oil flow pipe 5 is divided into two parts, one part is wound around the outside of the multiple exhaust gas flow pipes 6, and the other part extends into the inside of the exhaust gas flow pipe 6. The outside of the part of the heat transfer oil flow pipe 5 wound around the outside of the exhaust gas flow pipe 6, between the multiple exhaust gas flow pipes 6, between the exhaust gas flow pipe 6 and the part of the heat transfer oil flow pipe 5 wound around the outside of the exhaust gas flow pipe 6, and between the part of the heat transfer oil flow pipe 5 wound around the outside of the exhaust gas flow pipe 6 and the shell body 7 are all filled with phase change material molten salt. The automobile exhaust inlet flange 1 is connected to the automobile exhaust pipe, and the automobile exhaust gas enters the multiple exhaust gas flow pipes 6 through the first end cover 2. The phase change material molten salt exchanges heat with the automobile exhaust gas. The heat transfer oil in the heat transfer oil flow pipe 5 first exchanges heat with the molten salt, and then exchanges heat with the automobile exhaust gas. The heat transfer oil is discharged through the heat transfer oil outlet 11 and then sent into the automobile cabin. The exhaust gas after waste heat recovery is directly discharged into the atmosphere through the automobile exhaust outlet flange 9.

[0072] Furthermore, the exhaust gas flow pipe 6 adopts a 316 stainless steel pipe with an inner diameter of 26 mm and a wall thickness of 2 mm. Multiple exhaust gas flow pipes 6 are evenly arranged so that the exhaust gas is fully in contact with the molten salt and the heat transfer oil, and the heat transfer is uniform. A tube sheet is arranged in the heat pool shell, and the tube sheet is used to fix each flow pipe in the heat pool shell. The exhaust gas flow pipe 6 is connected to the tube sheet 3 by welding. The number of the exhaust gas flow pipes 6 is 7, which fully increases the heat exchange area between the exhaust gas and the heat transfer oil and the molten salt, and improves the heat exchange effect. 7 316 stainless steel pipes are used to flow automobile exhaust. These 7 stainless steel pipes are parallel to each other and arranged in space into a pentagon.

[0073] Furthermore, the heat transfer oil flowing in the heat transfer oil flow pipe 5 is 350# heat transfer oil. The flash boiling point of heat transfer oil is much higher than that of refrigerant, and it has higher thermal conductivity and thermal stability. Heat transfer oil can obtain a very high operating temperature under almost normal pressure conditions, which greatly reduces the operating pressure and safety requirements of the high-temperature heating system and improves the reliability of the system and equipment. Compared with traditional refrigerants, the heat transfer oil is not easy to gasify at a high temperature of 200 to 300 degrees, the air pressure in the pipe is relatively constant, and the air tightness requirements for the pipeline connection are relatively low, which reduces the impact of the change in air pressure in the pipe on the heat exchange efficiency of the heat exchanger.

[0074] Furthermore, the heat transfer oil flow pipe includes two sections of pipelines, namely the first pipeline and the second pipeline; the first pipeline is used for heat exchange between heat transfer oil and phase change material molten salt; the second pipeline is used for heat exchange between heat transfer oil and automobile exhaust gas; the first pipeline and the second pipeline are connected and sealed by a steel pipe and a ferrule joint 4. The heat transfer oil flow pipe 5 is divided into two parts, one part is wound around the outside of each exhaust gas flow pipe 6, and the other part is located inside the exhaust gas flow pipe 6. This design improves the efficiency and compactness of the heat exchanger. The heat transfer oil in the heat transfer oil flow pipe 5 changes its flow direction due to the complexity of the pipeline design, increases the flow distance, and increases the effective heat exchange area. The heat transfer oil flow pipe 5 adopts a corrugated pipe with a wall thickness of 2.25mm and an inner diameter of 10mm.

[0075] Furthermore, a through hole 12 with a diameter of 5 mm is formed on the upper side of the shell body, and a bolt is passed through the through hole 12 to seal the third end cover and the vessel wall, and the through hole 12 cooperates with the third end cover 13 to form a sealed space.

[0076] Furthermore, the first end cover 2 is provided with a heat transfer oil inlet 10 for replenishing the heat transfer oil in the heat transfer oil flow pipe 5. The automobile exhaust outlet flange 9 is used to discharge the automobile exhaust gas after waste heat recovery directly into the atmosphere, and the heat transfer oil inlet 10 is connected to the device storing the heat transfer oil by a ferrule joint.

[0077] Furthermore, the outer side of the heat pool shell is wrapped with a heat insulation layer, and the heat insulation layer is used to reduce heat loss; the heat insulation layer uses heat insulation cotton. Specifically, the outer side of the shell body 7, the outer side of the first end cover 2 and the outer side of the second end cover 8 are wrapped with heat insulation cotton material to reduce heat loss.

[0078] The working principle of the hot pool is:

[0079] When high-temperature automobile exhaust flows through multiple exhaust gas flow pipes 6, the heat will be quickly transferred to the molten salt. The molten salt absorbs heat and undergoes a phase change from a solid state to a molten state. The natural convection conduction of the molten salt will transfer the heat to the heat-conducting oil in the heat-conducting oil flow pipe 5. The heat-conducting oil will also absorb the heat brought by the exhaust gas. The temperature of the heat-conducting oil rises but does not vaporize. The air pressure in the pipeline is stable, and the heat-conducting oil is discharged through the heat-conducting oil outlet 11. The heat exchanger of the present invention can be used as a heat storage device to transfer the energy stored in the molten salt to the heat-conducting oil in the bellows, so that the heat-conducting oil can continue to absorb heat for a period of time.

[0080] In severe cold weather, the car engine needs to be cold-started and preheated, the battery needs to work at a certain temperature, and the cabin needs to maintain a certain degree of thermal comfort. The heat exchanger of the present invention can transfer the remaining heat previously stored in the phase change material molten salt to the coolant through the heat transfer oil, and then the coolant flows through the engine, battery and cabin heater core, thereby transferring the heat to the engine, battery and cabin. The heat exchanger can replace the automobile PTC to provide heat for the engine, battery and cabin, and can solve the problem of high energy consumption of traditional PTC leading to reduced driving range.

[0081] The thermal management system of the present invention can realize the control of multiple operating modes through the switching control of two five-way valves. The operating modes of the thermal management system include PTC cabin heating and battery mode, heat pool and PTC cabin heating and battery mode in pure electric state, heat pool heating engine mode, engine heat dissipation and heat pool heating cabin and battery mode in extended range state.

[0082] In the pure electric state, in the PTC heated cabin and battery mode, the outlet of the first water pump 24 is connected to the inlet of the PTC21, the outlet of the PTC21 is connected to the inlet of the heater core 22, the outlet of the heater core 22 is connected to the c port of the first five-way valve 23, the b port of the first five-way valve 23 is connected to the inlet one of the second heat exchanger 34, the outlet one of the second heat exchanger 34 is connected to the a port of the first five-way valve 23, the d port of the first five-way valve 23 is connected to the b port of the second five-way valve 19, and the c port of the second five-way valve 19 is connected to the inlet of the first water pump 24.

[0083] like Figure 2As shown, in the pure electric state, if the heat pool does not store heat, PTC is required to heat the cabin or the battery. The specific control is that the b port of the first five-way valve 23 is connected to the c port, the a port is connected to the d port, and the b port of the second five-way valve 23 is connected to the c port. PTC heat heating can be achieved to heat the cabin through the heater core, or to heat the battery 35 through the second heat exchanger 34, or both heating functions can be achieved simultaneously.

[0084] The working paths in this mode include:

[0085] The coolant flows out from the first water pump, flows through PTC21, at which time PTC21 is in the open state, the coolant temperature rises, and then flows into the heater core 22. The heat in the heater core 22 is blown into the cabin by the fan 26, and the temperature in the cabin is raised. Then, it flows through the first five-way valve 23, the second heat exchanger 34, the first five-way valve 23, the second five-way valve 19 in sequence, and finally returns to the water pump to form a circulation loop. Among them, the coolant in the coolant loop inside the battery and the coolant in the PTC coolant loop are heat exchanged in the second heat exchanger 34, and the temperature of the coolant in the coolant loop inside the battery 35 is raised. It flows through the third water pump 36, the battery 35, and the second heat exchanger 34 in sequence, bringing heat into the battery 35 to heat the battery 35.

[0086] Furthermore, in the pure electric state, the heat pool and PTC heating cabin and battery mode, the outlet of the heat pool 28 is connected to the inlet of the liquid storage tank 29, the outlet of the liquid storage tank 29 is connected to the inlet of the first heat exchanger 27, the outlet of the first heat exchanger 27 is connected to the inlet of the oil pump 30, the outlet of the oil pump 30 is connected to the inlet of the heat pool 28, and a three-way valve 31 is provided between the outlet of the oil pump 30 and the inlet of the heat pool 28; the outlet of the first water pump 24 is connected to the inlet of the PTC 21, the outlet of the PTC 21 is connected to the inlet of the heater core 22, and the heater core 2 2 is connected to the c port of the first five-way valve 23, the b port of the first five-way valve 23 is connected to the second heat exchanger 34, the inlet one of the second heat exchanger is connected to the a port of the first five-way valve, the d port of the first five-way valve is connected to the b port of the second five-way valve 19, and the a port of the second five-way valve 19 is connected to the inlet of the first heat exchanger 27; the outlet of the third water pump 36 is connected to the inlet of the battery cooling circuit, the outlet of the battery cooling circuit is connected to the inlet three of the second heat exchanger 34, and the outlet three of the second heat exchanger 34 is connected to the inlet of the third water pump 36.

[0087] like Figure 3As shown, in the pure electric state, if the heat pool 28 has stored heat, the heat in the heat pool 28 can be used to heat the cabin or the battery, or the heat pool + PTC can be used to heat the cabin or the battery together. The specific control is that the b port of the first five-way valve 23 is connected to the c port, the a port is connected to the d port, and the a port of the second five-way valve 19 is connected to the b port, so that the heat pool 28 can heat the cabin or the battery 35 alone through the first heat exchanger 27; if the heat pool does not have enough heat, the PTC can also be turned on, and the heat pool + PTC can be used to heat the cabin or the battery together.

[0088] The working paths in this mode include:

[0089] The heat transfer oil flows out of the oil pump 30, flows through the three-way valve 31, and then flows into the heat transfer oil flow pipe 5 in the heat pool 28, then flows through the liquid storage tank 29 and the first heat exchanger 27 in sequence, and finally returns to the oil pump 30 to form a circulation loop. In the coolant loop of the heater core 22, the coolant flows out of the water pump, passes through the PTC 21, the heater core 22, the first five-way valve 23, the second heat exchanger 34, the first five-way valve 23, the second five-way valve 19, the first heat exchanger 27 in sequence, and finally returns to the water pump to form a circulation loop. In the coolant loop inside the battery, the coolant flows out of the water pump, flows through the inside of the battery 35, the second heat exchanger 34 in sequence, and finally returns to the water pump to form a circulation loop. Among them, the heat transfer oil in the heat pool heat transfer oil circuit and the heater core circuit coolant are heat exchanged in the first heat exchanger 27, and the heater core circuit coolant and the coolant in the battery internal coolant circuit are heat exchanged in the second heat exchanger 34, bringing heat into the heater core 22 and the battery 35.

[0090] Further, in the heat pool heating engine mode under the thermal management in the extended range state, the outlet of the oil pump 30 is connected to the three-way valve 31, the three-way valve 31 is connected to the oil circuit inlet of the heat pool 28, the oil circuit outlet of the heat pool 28 is connected to the inlet of the liquid storage tank 29, the outlet of the liquid storage tank 29 is connected to the inlet of the first heat exchanger 27, and the outlet of the first heat exchanger 27 is connected to the inlet of the oil pump 30; the outlet of the engine coolant circuit is connected to the e port of the second five-way valve 19, the a port of the second five-way valve 19 is connected to the inlet of the first heat exchanger 27, the outlet of the first heat exchanger 27 is connected to the c port of the second five-way valve 19, the b port of the second five-way valve 19 is connected to the d port of the first five-way valve 19, the e port of the first five-way valve 19 is connected to the inlet of the second water pump 20, and the outlet of the second water pump 20 is connected to the inlet of the engine coolant circuit.

[0091] like Figure 4As shown, in the extended range state, if there is stored heat in the heat pool, the heat in the heat pool can be used to preheat the engine when the engine is cold started, thereby shortening the cold start time of the engine. Specifically, the d port of the first five-way valve 23 is connected to the e port, the a port of the second five-way valve 19 is connected to the e port, and the b port is connected to the c port, so that the heat pool can heat the engine separately through the first heat exchanger 27.

[0092] The working paths in this mode include:

[0093] The heat transfer oil flows out of the oil pump 30, flows through the three-way valve 31, flows into the heat transfer oil flow pipe of the heat pool 28, then flows through the liquid storage tank 29 and the first heat exchanger 27 in sequence, and finally returns to the oil pump 30 to form a circulation loop. In the engine coolant loop, the coolant flows out of the second water pump 20, flows through the engine 25, the second five-way valve 19, the first heat exchanger 27, the second five-way valve 19, the first five-way valve 23 in sequence, and finally returns to the second water pump 20 to form a circulation loop. Among them, the heat transfer oil in the heat transfer oil loop of the heat pool 28 and the coolant in the engine coolant loop perform heat exchange in the first heat exchanger 27, and transfers heat to the engine coolant, which is convenient for rapid temperature rise when the engine is cold started.

[0094] In the engine cooling and heat pool heating cabin and battery mode under the extended range thermal management, the outlet of the engine cooling circuit is connected to the e port of the second five-way valve 19, the d port of the second five-way valve 19 is connected to the inlet of the radiator 18, the outlet of the radiator 18 is connected to the inlet of the second water pump 20, and the outlet of the second water pump 20 is connected to the inlet of the engine cooling circuit; the outlet of the oil pump 30 is connected to the three-way valve 31, the three-way valve 31 is connected to the oil circuit inlet of the heat pool 28, the oil circuit outlet of the heat pool 28 is connected to the inlet of the liquid storage tank 29, the outlet of the liquid storage tank 29 is connected to the inlet of the first heat exchanger 27, and the first heat exchanger 2 7 is connected to the inlet of the oil pump 30; the outlet of the water pump is connected to the inlet of the PTC21, the outlet of the PTC21 is connected to the inlet of the heater core 22, the outlet of the heater core 22 is connected to the c port of the first five-way valve 23, the b port of the first five-way valve 23 is connected to the inlet one of the second heat exchanger 34, the outlet one of the second heat exchanger 34 is connected to the a port of the first five-way valve 23, the d port of the first five-way valve 23 is connected to the b port of the second five-way valve 19, the a port of the second five-way valve 23 is connected to the inlet of the first heat exchanger 27, and the outlet of the first heat exchanger 27 is connected to the inlet of the first water pump 24.

[0095] like Figure 5As shown, in the extended range state, after the engine 25 is started, the heat of the heat pool 28 can be used to heat the cabin or the battery and the engine can be cooled through the radiator at the same time. Specifically, the b port of the first five-way valve 23 is connected to the c port, the a port is connected to the d port, the a port of the second five-way valve 19 is connected to the b port, and the d port is connected to the e port, so that the heat pool 28 can heat the cabin or the battery 35 alone or simultaneously through the first heat exchanger 27, and the engine 25 can be cooled through the radiator 18.

[0096] The working paths of this mode include:

[0097] The heat transfer oil flows out of the oil pump 30, flows through the three-way valve 31, and then flows into the heat transfer oil flow pipe 5 of the heat pool 28, then flows through the liquid storage tank 29 and the first heat exchanger 27 in sequence, and finally returns to the oil pump 30 to form a circulation loop. In the heater core coolant loop, the coolant flows out of the first water pump 24, passes through the PTC 21, the heater core 22, the first five-way valve 23, the second heat exchanger 34, the first five-way valve 23, the second five-way valve 19, the first heat exchanger 27 in sequence, and finally returns to the first water pump 24 to form a circulation loop. In the engine large circulation cooling loop, the coolant flows out of the second water pump 20, flows through the engine 25, the second five-way valve 19, the radiator 18 in sequence, and finally returns to the second water pump 20 to form a circulation loop. The heat transfer oil in the heat transfer oil circuit of the heat pool 28 exchanges heat with the coolant in the heater core circuit in the first heat exchanger 27, bringing heat into the heater core 22 and taking heat out of the engine 25 to the outside.

[0098] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope of the claims of the present invention.

Claims

1. A heat pool for recovering waste heat from automobile exhaust using molten salt heat transfer and heat conduction, characterized in that: The heat pool (28) comprises a heat pool shell and a plurality of exhaust gas flow pipes (6) and a heat transfer oil flow pipe (5) installed in the heat pool shell; the plurality of exhaust gas flow pipes (6) are parallel to each other; the heat transfer oil flow pipe (5) comprises a first pipeline and a second pipeline connected in sequence; the first pipeline is wound around the outside of the plurality of exhaust gas flow pipes (6), and the second pipeline is located inside the exhaust gas flow pipe (6); the first pipeline is used for heat exchange between the heat transfer oil and the phase change material molten salt; The second pipeline is used for heat exchange between heat transfer oil and automobile exhaust gas; the heat pool shell contains molten salt of phase change material; the exhaust gas flow pipe (6) and the first pipeline are both in contact with the molten salt of phase change material.

2. The heat pool for recovering waste heat from automobile exhaust using molten salt heat transfer and heat conduction according to claim 1 is characterized in that: The heat pool shell comprises a shell body (7) and a first end cover (2) and a second end cover (8) respectively arranged at openings at both ends of the shell body (7); the shell body (7), the first end cover (2) and the second end cover (8) enclose a cavity; the first end cover (2) is mounted with an automobile exhaust gas inlet flange (1); the second end cover (8) is mounted with an automobile exhaust gas outlet flange (9); a through hole (12) is provided above the shell body; a third end cover (13) is mounted at the through hole (12); the third end cover (13) is used to seal the through hole (12); the first end cover (2) is connected to an automobile exhaust pipe, the automobile exhaust pipe is mounted on the first end cover (2) and is connected to the exhaust gas flow pipe (6); the automobile exhaust gas flows into the plurality of exhaust gas flow pipes (6) through the automobile exhaust pipe.

3. The heat pool for recovering automobile exhaust waste heat by using molten salt heat transfer and heat conduction according to claim 1 is characterized in that: The heat transfer oil flow pipe (5) is filled with heat transfer oil, which is 350# fully synthetic heat transfer oil. The heat transfer oil flow pipe (5) is provided with a heat transfer oil inlet (10) and a heat transfer oil outlet (11). The heat transfer oil inlet (10) is used to replenish the heat transfer oil in the heat transfer oil flow pipe (5); the heat transfer oil outlet (11) is used to discharge the heat transfer oil. The heat transfer oil in the heat transfer oil flow pipe (5) absorbs the heat of automobile exhaust gas and is discharged through the heat transfer oil outlet (11). The heat generated by the exhaust gas in the exhaust gas flow pipe (6) is recovered through the phase change material molten salt in the heat pool shell and the heat transfer oil in the heat transfer oil flow pipe, and the exhaust gas is discharged into the atmosphere through the automobile exhaust gas outlet flange (9).

4. The heat pool for recovering automobile exhaust waste heat by using molten salt heat transfer and heat conduction according to claim 1 is characterized in that: The exhaust gas flow pipe (6) is a 316 stainless steel pipe with an inner diameter of 26 mm and a wall thickness of 2 mm; the number of the exhaust gas flow pipes (6) is 7; a tube sheet (3) is provided in the heat pool shell; the exhaust gas flow pipe (6) is connected to the tube sheet (3) by welding.

5. The heat pool for recovering waste heat from automobile exhaust using molten salt heat transfer and heat conduction according to claim 1 is characterized in that: The first pipeline and the second pipeline are connected and sealed via a steel pipe and a ferrule joint (4); the heat transfer oil flow pipe (5) is a bellows having a wall thickness of 2.25 mm and an inner diameter of 10 mm.

6. The heat pool for recovering automobile exhaust waste heat by using molten salt heat transfer and heat conduction according to claim 1 is characterized in that: The phase change material molten salt is a mixture obtained by mixing sodium nitrate and potassium nitrate in a mass ratio of 6:

4.

7. The heat pool for recovering waste heat from automobile exhaust using molten salt heat transfer and heat conduction according to claim 1 is characterized in that: The outer side of the heat pool shell is wrapped with a heat-insulating layer, and the heat-insulating layer is used to reduce heat loss; the heat-insulating layer is made of heat-insulating cotton.

8. A thermal management system using a heat pool for recovering waste heat from automobile exhaust using molten salt heat transfer and heat conduction as claimed in any one of claims 1 to 7, characterized in that: The system comprises: an air conditioning circuit module, an engine circuit module, a heat pool heat release circuit module, a battery circuit module, a first five-way valve (23) and a second five-way valve (19); The air conditioning circuit module comprises a compressor (14), a condenser (15), a first expansion valve (16), an evaporator (17), a second water pump (20), a positive temperature coefficient thermistor (PTC) (21) and a heater core (22); the engine circuit module comprises a radiator (18), a fan (26), an engine (25) and a first water pump (20); the heat pool heat release circuit module comprises a heat pool (28), a liquid storage tank (29), a three-way valve (31), an oil pump (30) and a first heat exchanger (27); the battery circuit module comprises a third water pump (36), a battery (35) and a second heat exchanger (34); the heat pool (28) is as described in any one of claims 1 to 7; The outlet of the compressor (14) is connected to the inlet of the condenser (15), the outlet of the condenser (15) is connected to the inlet of the first expansion valve (16), the outlet of the first expansion valve (16) is connected to the inlet of the evaporator (17), the outlet 1 of the second heat exchanger (34) is connected to the port a of the first five-way valve (23), the inlet 1 of the second heat exchanger (34) is connected to the port b of the first five-way valve (23), the outlet 2 of the second heat exchanger (34) is connected to the inlet of the compressor (14) and the outlet of the evaporator (17), and the outlet 3 of the second heat exchanger (24) is connected to the inlet of a third water pump (36); the outlet of the evaporator (17) is connected to the inlet of the compressor (14), thereby forming a refrigeration circuit for an automobile air conditioner; The outlet of the first water pump (24) is connected to the inlet of the coolant circuit of the engine (25), the outlet of the coolant circuit of the engine (25) is connected to the e port of the second five-way valve (19), the b port of the second five-way valve (19) is connected to the d port of the first five-way valve (23), and the e port of the first five-way valve (23) is connected to the inlet of the first water pump (24), thereby forming a small circulation loop of the engine coolant; The d port of the second five-way valve (19) is connected to the inlet of the radiator (18), and the outlet of the radiator (18) is connected to the inlet of the first water pump (24), thereby forming a large circulation loop of the engine coolant; The exhaust gas outlet of the engine (25) is connected to the exhaust gas inlet of the heat pool (28), the exhaust gas outlet of the heat pool (28) is connected to the exhaust pipe, the heat transfer oil outlet of the heat pool (28) is connected to the inlet 1 of the liquid storage tank (29), the outlet of the liquid storage tank (29) is connected to the inlet of the oil pump (30), the outlet of the oil pump (30) is connected to the port 1 of the three-way valve (31), the port 2 of the three-way valve (31) is connected to the heat transfer oil inlet of the heat pool (28), and the port 3 of the three-way valve (31) is connected to the inlet 2 of the liquid storage tank (29), thereby forming a heat transfer oil circuit; The first heat exchanger (27) is connected to the port a of the second five-way valve (19), the port c of the second five-way valve (19) is connected to the inlet of the second water pump (20), the outlet of the second water pump (20) is connected to the inlet of the PTC (21), the outlet of the PTC (21) is connected to the inlet of the heater core (22), the outlet of the heater core (22) is connected to the port c of the first five-way valve (23), and the port b of the first five-way valve (23) is connected to the port d of the second five-way valve (19), thereby forming a cabin heating circuit; The outlet of the condenser (15) is connected to the inlet of the second expansion valve (33), the outlet of the second expansion valve (33) is connected to the inlet of the second heat exchanger (34), and the outlet of the second expansion valve (33) is connected to the inlet of the second heat exchanger (34), thereby forming an air conditioning cooling battery pack circuit; The outlet of the third water pump (36) is connected to the inlet of the battery internal coolant circuit, the outlet of the battery internal coolant circuit is connected to the inlet of the second heat exchanger (34), and the outlet of the second heat exchanger (34) is connected to the inlet of the third water pump (36), thereby forming a battery internal coolant circuit.

9. The thermal management system according to claim 8, characterized in that: The operating modes of the thermal management system include PTC cabin and battery heating mode, heat pool and PTC cabin and battery heating mode in pure electric state, heat pool engine heating mode and engine heat dissipation and heat pool cabin and battery heating mode in extended range state; In the PTC cabin heating and battery mode in the pure electric state, the outlet of the second water pump (20) is connected to the inlet of the PTC (21), the outlet of the PTC (21) is connected to the inlet of the heater core (22), the outlet of the heater core (22) is connected to the c port of the first five-way valve (23), the b port of the first five-way valve (23) is connected to the inlet 1 of the second heat exchanger (34), the outlet 1 of the second heat exchanger (34) is connected to the a port of the first five-way valve (23), the d port of the first five-way valve (23) is connected to the b port of the second five-way valve (19), and the c port of the second five-way valve (19) is connected to the inlet of the second water pump (20); In the pure electric state, the heat pool and PTC cabin heating and battery mode, the outlet of the heat pool (28) is connected to the inlet of the liquid storage tank (29), the outlet of the liquid storage tank (29) is connected to the inlet of the first heat exchanger (27), the outlet of the first heat exchanger (27) is connected to the inlet of the oil pump (30), the outlet of the oil pump (30) is connected to the inlet of the heat pool (28), and a three-way valve (31) is provided between the outlet of the oil pump (30) and the inlet of the heat pool (28); the outlet of the second water pump (20) is connected to the inlet of the PTC (21), the outlet of the PTC (21) is connected to the inlet of the heater core (22), and the outlet of the heater core (22) is connected to the inlet of the heater core (22). The c port of the first five-way valve (23) is connected, the b port of the first five-way valve (23) is connected to the inlet 1 of the second heat exchanger (34), the outlet 1 of the second heat exchanger (34) is connected to the a port of the first five-way valve (23), the d port of the first five-way valve (23) is connected to the b port of the second five-way valve (19), and the a port of the second five-way valve (19) is connected to the inlet of the first heat exchanger (1); the outlet of the third water pump (36) is connected to the inlet of the cooling circuit of the battery (35), the outlet of the cooling circuit of the battery (35) is connected to the inlet 3 of the second heat exchanger (34), and the outlet 3 of the second heat exchanger (34) is connected to the inlet of the third water pump (36); In the heat pool heating engine mode under the extended range thermal management, the outlet of the oil pump (30) is connected to the first port of the three-way valve (31), the second port of the three-way valve (31) is connected to the oil circuit inlet of the heat pool (28), the third port of the three-way valve (31) is connected to the second inlet of the liquid storage tank (29), the oil circuit outlet of the heat pool (28) is connected to the inlet of the liquid storage tank (29), the outlet of the liquid storage tank (29) is connected to the inlet of the first heat exchanger (27), and the outlet of the first heat exchanger (27) is connected to the inlet of the oil pump (30); the engine ( The outlet of the coolant circuit of the engine (25) is connected to the e port of the second five-way valve (19), the a port of the second five-way valve (19) is connected to the inlet of the first heat exchanger (27), the outlet of the first heat exchanger (27) is connected to the c port of the second five-way valve (19), the b port of the second five-way valve (19) is connected to the d port of the first five-way valve (23), the e port of the first five-way valve (23) is connected to the inlet of the first water pump (20), and the outlet of the first water pump (20) is connected to the inlet of the coolant circuit of the engine (25); In the extended range thermal management mode of engine heat dissipation and cabin heating by heat pool and battery mode, the outlet of the coolant circuit of the engine (25) is connected to the e port of the second five-way valve (19), the d port of the second five-way valve (19) is connected to the inlet of the radiator (18), the outlet of the radiator (18) is connected to the inlet of the first water pump (20), and the outlet of the first water pump (20) is connected to the inlet of the coolant circuit of the engine; the outlet of the oil pump (30) is connected to the first port of the three-way valve (31), the second port of the three-way valve (31) is connected to the oil circuit inlet of the heat pool (28), the oil circuit outlet of the heat pool (28) is connected to the inlet of the liquid storage tank (29), the outlet of the liquid storage tank (29) is connected to the inlet of the first heat exchanger (27), and the first heat exchanger (27) is connected to the inlet of the first heat exchanger (27). The outlet of the heat exchanger (27) is connected to the inlet of the oil pump (30); the outlet of the second water pump (20) is connected to the inlet of the PTC (21), the outlet of the PTC (21) is connected to the inlet of the heater core (22), the outlet of the heater core (22) is connected to the c port of the first five-way valve (23), the b port of the first five-way valve (23) is connected to the inlet 1 of the second heat exchanger (34), the outlet 1 of the second heat exchanger (34) is connected to the a port of the first five-way valve (23), the d port of the first five-way valve (23) is connected to the b port of the second five-way valve (19), the a port of the second five-way valve (19) is connected to the inlet of the first heat exchanger (27), and the outlet of the first heat exchanger (27) is connected to the inlet of the second water pump (20).

10. The thermal management system according to claim 9, characterized in that: The working method of the thermal management system comprises the following steps: The operating modes of the thermal management system include PTC cabin and battery heating mode, heat pool and PTC cabin and battery heating mode in pure electric state, heat pool engine heating mode and engine heat dissipation and heat pool cabin and battery heating mode in extended range state; S1, PTC heating cabin and battery mode in pure electric state The coolant flows out from the first water pump (24) and flows through the PTC (21). At this time, the PTC (21) is in an open state, the temperature of the coolant rises, and then flows into the heater core (22). The heat in the heater core (22) is blown into the cabin by the fan, so that the temperature in the cabin is increased. Then, after the coolant flows out from the heater core (22), it flows into the c port of the first five-way valve (23), and then flows from the c port of the first five-way valve (23) to the b port of the first five-way valve (23), and then flows from the b port of the first five-way valve (23) to the inlet 1 of the second heat exchanger (34), and then flows from the outlet 1 of the second heat exchanger (34) to the a port of the first five-way valve (23), and then flows from the first five-way valve (23) to the outlet 1 of the first five-way valve (23). The water flows from the a port of the first five-way valve (23) to the d port of the first five-way valve (23), flows from the d port of the first five-way valve (23) to the b port of the second five-way valve (19), flows from the b port of the second five-way valve (19) to the c port of the second five-way valve (19), and finally returns to the second water pump (20) to form a circulation loop; wherein the coolant in the coolant loop of the battery (35) and the coolant in the coolant loop of the PTC (21) are heat-exchanged in the second heat exchanger (34), the temperature of the coolant in the coolant loop of the battery (35) is increased, and the coolant flows through the third water pump (36), the battery (35), and the second heat exchanger (34) in sequence, bringing heat into the battery (35) to heat the battery (35); S2: Heat pool and PTC heated cabin and battery mode in pure electric state The heat transfer oil flows out from the oil pump (30), flows through the three-way valve (31), and then flows into the heat transfer oil flow pipe in the heat pool (28), then flows through the liquid storage tank (29) and the first heat exchanger (27) in sequence, and finally returns to the oil pump (30) to form a circulation loop; in the coolant loop of the heater core (22), the coolant flows out from the second water pump (20), and passes through the PTC (21), the heater core (22), the passage between the c port and the b port of the first five-way valve (23), the second heat exchanger (34), the passage between the a port and the d port of the first five-way valve (23), the passage between the b port and the a port of the second five-way valve (19), and the first heat exchanger (27). Finally, the coolant returns to the second water pump (20) to form a circulation loop; in the coolant loop of the battery (35), the coolant flows out from the third water pump (36), flows through the inside of the battery (35) and the second heat exchanger (34) in sequence, and finally returns to the third water pump (36) to form a circulation loop; wherein the heat transfer oil in the heat transfer oil loop of the heat pool (28) and the coolant in the coolant loop of the heater core (22) perform heat exchange in the first heat exchanger (27), and the coolant in the coolant loop of the heater core (22) and the coolant in the coolant loop of the battery (35) perform heat exchange in the second heat exchanger (34), thereby bringing heat into the heater core (22) and the battery (35); S3, thermal pool heating engine mode under extended range thermal management The heat transfer oil flows out of the oil pump (30), flows through the three-way valve (31), flows into the heat transfer oil flow pipe of the heat pool (28), then flows through the liquid storage tank (29) and the first heat exchanger (27) in sequence, and finally returns to the oil pump (30) to form a circulation loop; in the coolant loop of the engine (25), the coolant flows out of the first water pump (24), flows through the engine (25), the e port of the second five-way valve (19), the a port of the second five-way valve (19), the first heat exchanger (27), the second five-way valve ( The heat transfer oil in the heat transfer oil circuit of the heat pool (28) and the coolant in the coolant circuit of the engine (25) are heat-exchanged in the first heat exchanger (27), and the heat is transferred to the coolant in the coolant circuit of the engine (25), so as to be used for rapid temperature rise during cold start of the engine; S4, engine cooling and hot pool cabin heating under extended range thermal management, battery mode The heat transfer oil flows out from the oil pump (30), flows through the three-way valve (31), and then flows into the heat transfer oil flow pipe of the heat pool (28), then flows through the liquid storage tank (29) and the first heat exchanger (27) in sequence, and finally returns to the oil pump (30) to form a circulation loop; in the coolant loop of the heater core (22), the coolant flows out from the second water pump (20), passes through the PTC (21) and the heater core (22) in sequence, flows through the c port of the first five-way valve (23), flows to the b port of the first five-way valve (23), flows to the inlet 1 of the second heat exchanger (34), flows from the outlet 1 of the second heat exchanger (34) to the a port of the first five-way valve (23), flows out from the d port of the first five-way valve (23) to the b port of the second five-way valve (19), and flows from the a port of the second five-way valve (19). The coolant flows out of the first water pump (24), flows through the engine (25), flows to the e port of the second five-way valve (19), flows out of the d port of the second five-way valve (19), flows to the inlet of the radiator (18), and flows from the outlet of the radiator (18) to the inlet of the first water pump (24), forming a circulation loop; the coolant flows out of the first water pump (24), flows through the engine (25), flows to the e port of the second five-way valve (19), flows out of the d port of the second five-way valve (19), flows to the inlet of the radiator (18), and flows from the outlet of the radiator (18) to the inlet of the first water pump (24), forming a circulation loop; the heat transfer oil in the heat transfer oil circuit of the heat pool (28) and the coolant in the coolant circuit of the heater core (22) perform heat exchange in the first heat exchanger (27), bringing heat into the heater core (22) and bringing heat out from the inside of the engine (25) to the outside.

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