阅读说明：本技术 一种基于热泵-热机双向循环的发动机余热余能综合利用系统及其方法 (Engine waste heat and complementary energy comprehensive utilization system and method based on heat pump-heat engine bidirectional circulation ) 是由 俞小莉 俞潇南 王雷 陆奕骥 黄瑞 黄岩 常晋伟 李智 姜睿铖 肖永红 刘开敏 于 2019-09-09 设计创作，主要内容包括：本发明公开了一种基于热泵-热机双向循环的发动机余热余能综合利用系统及其方法,包括热力循环系统和发动机及其子系统；热力循环系统视具体发动机工况通过热泵循环将发动机曲轴动能转换为储热介质热能,通过热机循环将储存下来的热能转换为曲轴动能补充发动机工况；发动机及其子系统为本发明余热、余能源,发动机尾气流经热力循环系统的显热-潜热复合储热换热器将废热储存下来；本发明充分利用发动机制动时的余能及正常工作时尾气的余热,降低排放,提高热效率。(The invention discloses a heat pump-heat engine bidirectional circulation-based engine waste heat and complementary energy comprehensive utilization system and a method thereof, wherein the system comprises a thermodynamic circulation system, an engine and subsystems thereof; the heat circulation system converts the kinetic energy of the crankshaft of the engine into heat energy of a heat storage medium through heat pump circulation according to the specific working condition of the engine, and converts the stored heat energy into the kinetic energy of the crankshaft through heat engine circulation to supplement the working condition of the engine; the engine and the subsystems thereof are waste heat and residual energy sources, and the tail gas of the engine flows through a sensible heat-latent heat composite heat storage heat exchanger of a thermal circulation system to store the waste heat; the invention fully utilizes the residual energy of the engine during braking and the residual heat of the tail gas during normal work, reduces the emission and improves the heat efficiency.)

1. A comprehensive utilization system of engine waste heat and complementary energy based on heat pump-heat engine bidirectional circulation is characterized by comprising a thermodynamic cycle system (S1), an engine and a subsystem (S2) thereof;

an engine tail gas path (R1) of the engine and a subsystem (S2) thereof passes through the sensible heat-latent heat composite heat storage heat exchanger (4) of the thermal circulation system (S1) to enable tail gas to exchange heat with a heat storage medium in the sensible heat-latent heat composite heat storage heat exchanger (4); the mechanical shaft of the volumetric expansion-compressor (3) of the thermodynamic cycle system (S1) is connected with the engine crankshaft (1) of the engine and its subsystems (S2) through a clutch (2).

2. The system for comprehensively utilizing the residual heat and the complementary energy of the engine based on the heat pump-heat engine two-way circulation is characterized in that the thermodynamic cycle system (S1) comprises a volumetric expansion-compressor (3), a sensible heat-latent heat composite heat storage heat exchanger (4), a three-way valve A (5), an expansion valve (6), a working medium pump (7), a three-way valve B (8) and an environment heat exchanger (9); the thermodynamic cycle working medium carries out forward heat engine cycle or reverse heat pump cycle in a working medium circulation path (R2) of the thermodynamic cycle system (S1); the mechanical shaft of the positive displacement expansion-compressor (3) is connected with the clutch (2) of the engine and the subsystem (S2) thereof, and two ends of a working medium outlet/inlet of the positive displacement expansion-compressor (3) are respectively connected with a working medium port on one side of the environment heat exchanger (9) and the sensible heat-latent heat composite heat storage heat exchanger (4); a circulating working medium flow channel and an engine tail gas flow channel are arranged in the sensible heat-latent heat composite heat storage heat exchanger (4), an inlet of the engine tail gas flow channel is communicated with an outlet of an exhaust pipe of an engine and a subsystem (S2) of the engine, and an outlet of the engine tail gas flow channel is communicated with the atmosphere, so that an engine tail gas path (S2) is formed; the outlet/inlet of the circulating working medium flow passage is respectively connected with the positive displacement expansion-compressor (3) and a first flow passage opening of a three-way valve A (5), a third flow passage opening of the three-way valve A (5) is connected with a third flow passage opening of a three-way valve B (8) through an expansion valve (6), a second flow passage of the three-way valve A (5) is connected with a second flow passage opening of the three-way valve B (8) through a working medium pump (7), and the first flow passage opening of the three-way valve B (8) is connected with a working medium opening on the other side of the environment heat exchanger (; the environment heat exchanger (9) is a working medium and environment heat exchange place.

3. The system for comprehensively utilizing the residual heat and the surplus energy of the engine based on the heat pump-heat engine bidirectional circulation as claimed in claim 2, characterized in that the heat storage medium in the sensible heat-latent heat composite heat storage heat exchanger (4) is a composite material of a sensible heat storage material and a latent heat storage material.

4. The comprehensive utilization method of the residual heat and the complementary energy of the engine based on the heat pump-heat engine bidirectional cycle of the system as claimed in claim 1 is characterized in that:

when the engine is braked, the system enters an engine braking mode, at the moment, a positive displacement expansion-compressor (3) of the thermodynamic cycle system (S1) works in a compressor mode, and thermodynamic cycle working media perform reverse heat pump circulation in a working media circulation path (R2) of the thermodynamic cycle system (S1); the engine and an engine crankshaft (1) of the subsystem (S2) of the engine are connected with the positive displacement expansion-compressor (3) through the clutch (2) to drag the positive displacement expansion-compressor to work, and the thermodynamic cycle working medium is pressurized to a high-temperature and high-pressure state in the positive displacement expansion-compressor (3); then the working medium enters a sensible heat-latent heat composite heat storage heat exchanger (4) of the thermodynamic cycle system (S1), heat is transferred to a heat storage medium, and the working medium is cooled to a low-temperature high-pressure state; in the mode, a first flow port and a third flow port of a three-way valve A (5) are communicated, a third flow port and a second flow port of a three-way valve B (8) are communicated, so that the working medium flows through an expansion valve (6) of the thermodynamic cycle system (S1), the working medium is expanded, the temperature and the pressure are reduced, and the temperature is reduced to be lower than the ambient temperature; finally, the working medium flows into an environment heat exchanger (9) of the thermodynamic cycle system (S1) to be heated to an initial state, and then enters a positive displacement expansion-compressor (3) to enter the next cycle; kinetic energy generated when the engine is braked is converted into heat energy of the heat storage medium to be stored by the thermodynamic cycle, and the recovery of braking complementary energy of the engine is realized;

when the engine works normally, the system enters a normal working mode of the engine, at the moment, the positive displacement expansion-compressor (3) of the thermodynamic cycle system (S1) works in an expander mode, and thermodynamic cycle working media perform forward heat engine circulation in a working media circulation path (R2) of the thermodynamic cycle system (S1); in the mode, a first flow opening and a second flow opening of the three-way valve A (5) are communicated, a first flow opening and a second flow opening of the three-way valve B (8) are communicated, so that working media flow through a working medium pump (7) of the thermodynamic cycle system (S1), and the pressure of the working media is increased through the working medium pump (7); then the working medium enters a sensible heat-latent heat composite heat storage heat exchanger (4) of the thermal circulation system (S1), absorbs heat of a heat storage medium and enters a high-temperature and high-pressure state; then the working medium enters a positive displacement expansion-compressor (3) to do work through expansion, the mechanical work output by the positive displacement expansion-compressor (3) is transmitted to the engine crankshaft (1) of the engine and a subsystem (S2) of the engine through a clutch (2), and the pressure and the temperature of the expanded working medium are reduced; finally, the working medium flows into an environment heat exchanger (9) of the thermodynamic cycle system (S1) to be further cooled to the environment temperature, and then enters a working medium pump (7) to enter the next cycle; the heat energy stored by the heat storage medium is converted into the kinetic energy of the engine crankshaft (1) by the thermodynamic cycle, so that the power of the engine in normal operation is supplemented, and the engine can work under a better working condition; in addition, in the mode, the tail gas of the engine flows through the sensible heat-latent heat composite heat storage heat exchanger (4) of the thermal circulation system (S1) to transfer waste heat in the tail gas to the heat storage medium, so that the recovery of the waste heat of the tail gas of the engine is realized.

Technical Field

The invention relates to the field of energy, in particular to the field of recycling of waste heat and complementary energy of an engine, and particularly relates to a system and a method for comprehensively utilizing the waste heat and complementary energy of the engine based on heat pump-heat engine bidirectional circulation.

Technical Field

The effective improvement of the engine efficiency has become the direction of common efforts in the technical field of traditional internal combustion engines.

The engine waste heat recovery technology is an effective mode, waste heat in engine tail gas or cooling water is utilized to evaporate thermodynamic cycle working medium, so that the working medium expands in an expander to do work, low-grade waste heat is converted into high-grade electric energy or mechanical energy, and the overall efficiency of an engine is improved.

The engine braking residual energy recovery technology is another technical means aiming at improving the efficiency of the engine, when the engine is in a braking working condition, a valve mechanism is reasonably designed, the engine works in an air compressor mode, compressed air is stored in an air storage tank, so that the kinetic energy of the engine is converted into the energy release of the compressed air, and the recovery of the braking residual energy is realized.

At present, researchers respectively research Organic Rankine Cycle (ORC) and engine exhaust compression braking aiming at waste heat and complementary energy recovery of an engine, but a technical scheme of simultaneously utilizing tail gas waste heat and braking complementary energy does not exist.

Disclosure of Invention

The invention aims to provide a heat pump-heat engine bidirectional circulation-based engine waste heat and complementary energy comprehensive utilization system and a method thereof, aiming at overcoming the defects in the prior art, the heat pump can be used for circularly recovering the engine braking complementary energy, the engine waste heat is fully utilized, and the mechanical work is output to a crankshaft in a heat engine circulation mode to be supplemented, so that the fuel consumption of the engine is reduced, the emission is reduced, and the efficiency of the engine is improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention discloses a heat pump-heat engine bidirectional circulation-based engine waste heat and complementary energy comprehensive utilization system, which comprises a thermal circulation system, an engine and subsystems thereof;

the tail gas of the engine and the subsystem passes through the sensible heat-latent heat composite heat storage heat exchanger of the thermodynamic cycle system, so that the tail gas exchanges heat with the heat storage medium in the sensible heat-latent heat composite heat storage heat exchanger; the mechanical shaft of the volumetric expansion-compressor of the thermodynamic cycle system is connected with the engine crankshaft of the engine and the subsystems thereof through a clutch.

As a preferred scheme of the invention, the thermodynamic cycle system is a subsystem for performing positive and negative thermodynamic cycle, and comprises a volumetric expansion-compressor, a sensible heat-latent heat composite heat storage heat exchanger, a three-way valve A, an expansion valve, a working medium pump, a three-way valve B and an environment heat exchanger; the thermodynamic cycle working medium carries out forward heat engine cycle or reverse heat pump cycle in a working medium circulation path of the thermodynamic cycle system; the mechanical shaft of the positive displacement expansion-compressor is connected with the engine and a clutch of a subsystem of the engine, two ends of a working medium outlet/inlet of the positive displacement expansion-compressor are respectively connected with a working medium port on one side of the environmental heat exchanger and the sensible heat-latent heat composite heat storage heat exchanger, and according to the specific working mode of the engine and the specific thermodynamic cycle, the positive displacement expansion-compressor can work in an expander mode or a compressor mode according to different flow directions of the working medium; a circulating working medium flow channel and an engine tail gas flow channel are arranged in the sensible heat-latent heat composite heat storage heat exchanger, an inlet of the engine tail gas flow channel is communicated with an outlet of an exhaust pipe of an engine and a subsystem of the engine, and an outlet of the engine tail gas flow channel is communicated with the atmosphere, so that an engine tail gas path is formed; the outlet/inlet of the circulating working medium flow passage is respectively connected with the positive displacement expansion-compressor and a first flow passage opening of the three-way valve A, a third flow passage opening of the three-way valve A is connected with a third flow passage opening of the three-way valve B through the expansion valve, a second flow passage of the three-way valve A is connected with a second flow passage opening of the three-way valve B through the working medium pump, and the first flow passage opening of the three-way valve B is connected with a working medium opening at the other side; the environment heat exchanger is a working medium and environment heat exchange place.

As a preferable scheme of the invention, the heat storage medium in the sensible heat-latent heat composite heat storage heat exchanger is a composite material in which a sensible heat storage material and a latent heat storage material are arranged according to a certain specification and mode, and internal heat exchange structures in different arrangement modes are all within the protection scope of the invention.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention fully utilizes the braking characteristic of the engine, and realizes the recovery of the braking waste energy of the engine by converting the heat into the heat energy in the heat storage medium through thermal cycle.

(2) The invention fully utilizes the emission characteristic of the engine during working, stores the engine waste gas in the heat storage medium in a heat storage mode, realizes the recovery of the waste heat of the engine and reduces the waste energy emission of the engine.

(3) The invention converts the waste energy recovered during the braking of the engine and the waste heat during the normal work into the mechanical work of the expansion machine to supplement the power of the engine through the positive heat engine cycle, so that the engine works under the environment of better working condition and the fuel consumption of the engine is reduced.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention;

FIG. 2 is a schematic diagram of the engine braking mode system operation of the present invention;

FIG. 3 is a schematic diagram of the normal engine operating mode system of the present invention;

the system comprises an engine crankshaft 1, an engine 2, a clutch 3, a volumetric expansion/compressor, a 4-sensible heat-latent heat composite heat storage heat exchanger, a 5-three-way valve A, a 6-expansion valve, a 7-working medium pump, an 8-three-way valve B, an 9-environment heat exchanger, an R1-engine tail gas path and an R2-working medium circulation path.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings, but the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Referring to fig. 1, the invention firstly discloses a heat pump-heat engine bidirectional circulation-based engine waste heat and complementary energy comprehensive utilization system, which comprises a thermal circulation system S1, an engine and a subsystem S2 thereof.

Referring to fig. 1, the thermodynamic cycle system S1 is a subsystem for performing a forward thermodynamic cycle and a reverse thermodynamic cycle, and includes: the mechanical shaft of the positive displacement expansion-compressor 3 is connected with the clutch 2, the two ends of the working medium inlet and outlet are respectively connected with the sensible heat-latent heat composite heat storage heat exchanger 4 and the environment heat exchanger 9, and the working medium can be used as an expander or a compressor according to the specific working mode of the engine and the specific thermodynamic cycle; the sensible heat-latent heat composite heat storage heat exchanger 4 is internally provided with a shell-and-tube structure in which sensible heat storage materials and latent heat storage materials are arranged according to a certain specification and mode, and is internally provided with a circulating working medium flow channel and an engine tail gas flow channel, wherein two flow channel ports of the circulating working medium flow channel are respectively connected with the volumetric expansion/compressor 3 and a three-way valve A5 of the thermodynamic cycle system S1, and in addition, two flow channel ports of the engine tail gas flow channel are respectively connected with an outlet of an engine tail gas path R1 of the engine and a subsystem S2 thereof and the atmosphere; the three-way valve A5 is provided with three working medium flow passage ports which are respectively connected with the sensible heat-latent heat composite heat storage heat exchanger 4, the working medium pump 7 and the expansion valve 6; the working medium inlet and outlet of the expansion valve 6 are respectively connected with a three-way valve A5 and a three-way valve B8; the working medium inlet and outlet of the working medium pump 7 are respectively connected with the three-way valve A5 and the three-way valve B8, which are different from the interfaces of the expansion valve 6; three working medium flow passage ports of the three-way valve B8 are respectively connected with the environment heat exchanger 9, the working medium pump 7 and the expansion valve 6; the environment heat exchanger 9 is a place for exchanging heat between the working medium and the environment, and the working medium ports of the environment heat exchanger are respectively connected with the three-way valve B8 and the positive displacement expansion-compressor 3.

Referring to fig. 1, the engine and its subsystem S2 as the residual heat and energy source of the present invention includes: the two ends of the clutch 2 are respectively connected with the mechanical shaft of the positive displacement expansion-compressor 3 of the thermodynamic cycle system S1 and the engine crankshaft 1; an engine crankshaft 1, the front end of which is connected with a clutch 2; the engine tail gas path R1 flows into the flow channel port different from the inlet and outlet of the circulating working medium in the sensible heat-latent heat composite heat storage heat exchanger 4 of the thermodynamic cycle system S1 after coming out of the exhaust manifold, and is exhausted to the atmosphere after flowing through the sensible heat-latent heat composite heat storage heat exchanger 4.

As a preferred embodiment of the present invention, the thermodynamic cycle working fluid is subjected to a forward heat engine cycle or a reverse heat pump cycle in the working fluid circulation loop R2 of the thermodynamic cycle system (S1); when the volumetric expansion-compressor 3 works in an expander mode, the three-way valve A5 and the three-way valve B8 are communicated through the working medium pump 7, and the working medium pump 7, the three-way valve A5, the sensible heat-latent heat composite heat storage heat exchanger 4, the volumetric expansion-compressor 3, the environment heat exchanger 9 and the three-way valve B8 form a forward heat engine circulation loop; when the volumetric expansion-compressor 3 operates in the compressor mode, the three-way valve a5 and the three-way valve B8 are connected through the expansion valve 6, and the volumetric expansion-compressor 3, the sensible heat-latent heat composite heat storage heat exchanger 4, the three-way valve a5, the expansion valve 6, the three-way valve B8, and the ambient heat exchanger 9 constitute a reverse heat pump circulation circuit.

The working process of the invention is as follows:

referring to fig. 2, when the engine is braked, the system enters an engine braking mode, and a working medium circulation path R2 is as shown in fig. 2, at this time, the volumetric expansion-compressor 3 of the thermodynamic cycle system S1 works in a compressor mode, the engine and the engine crankshaft 1 of the subsystem S2 of the engine are connected with the volumetric expansion-compressor 3 through the clutch 2, and drag the volumetric expansion-compressor 3 to work, and the thermodynamic cycle working medium is pressurized to a high-temperature and high-pressure state in the volumetric expansion-compressor 3; then the working medium enters a sensible heat-latent heat composite heat storage heat exchanger 4 of the thermodynamic cycle system S1, heat is transferred to a heat storage medium, and the working medium is cooled to a low-temperature high-pressure state; in this mode, the three-way valve a5 and the three-way valve B8 of the thermodynamic cycle system S1 control the working medium circuit, so that the working medium flows through the expansion valve 6 of the thermodynamic cycle system S1, the working medium is expanded, the temperature and the pressure are reduced, and the temperature is reduced to be lower than the ambient temperature; finally, the working medium flows into the environment heat exchanger 9 of the thermodynamic cycle system S1 to be heated to an initial state, and then enters the volumetric expansion-compressor 3 to enter the next cycle; the thermal cycle realizes that the kinetic energy of the engine during braking is converted into the heat energy of the heat storage material to be stored, and the recovery of the braking residual energy of the engine is realized.

Referring to fig. 3, when the engine normally works, the system enters a normal working mode of the engine, the working medium circulation path R2 is as shown in fig. 3, at this time, the three-way valve a5 and the three-way valve B8 of the thermodynamic cycle system S1 control a working medium loop, so that the working medium flows through the working medium pump 7 of the thermodynamic cycle system S1, and the working medium is boosted through the working medium pump 7; then the working medium enters a sensible heat-latent heat composite heat storage heat exchanger 4 of the thermodynamic cycle system S1, absorbs heat of a heat storage medium and enters a high-temperature and high-pressure state; in this mode, the volumetric expansion-compressor 3 of the thermodynamic cycle system S1 works in an expander mode, the working medium enters the volumetric expansion-compressor 3 to perform expansion and work, the mechanical work output by the volumetric expansion-compressor 3 is transmitted to the engine crankshaft 1 of the engine and its subsystem S2 through the clutch 2, and the pressure and temperature of the expanded working medium are both reduced; finally, the working medium flows into the environment heat exchanger 9 of the thermodynamic cycle system S1 to be further cooled to the environment temperature, and then enters the working medium pump 7 to enter the next cycle; the heat energy stored by the heat storage material is converted into the kinetic energy of the crankshaft of the engine by the thermodynamic cycle, so that the power of the engine in normal operation is supplemented, and the engine can work under a better working condition. In addition, in this mode, the engine exhaust gas flows through the sensible heat-latent heat composite heat storage heat exchanger 4 of the thermal cycle system S1, and the waste heat in the exhaust gas is transferred to the heat storage medium, so that the recovery of the engine exhaust gas waste heat is realized.