Internal combustion engine waste heat recovery method and system

Abstract

The invention discloses an internal combustion engine waste heat recovery method and system.The method comprises the steps that waste gas generated in a combustion cylinder of an internal combustion engine is input into a catalytic evaporator, and heat of the waste gas is used for heating a low-temperature working medium in the catalytic evaporator; when a low-temperature working medium in the catalytic evaporator is heated and vaporized, a vapor-state working medium is formed, the distribution valve is controlled to input the vapor-state working medium into the working medium expansion cylinder to expand and do work, the vapor-state working medium is input into the working medium condenser to be cooled after being discharged, and low-temperature liquid flow is obtained; the low-temperature liquid flow is input into a first working medium pump; a distribution valve is controlled to input the non-vaporized low-temperature working medium in the catalytic evaporator into a first working medium pump; the liquid working medium in the first working medium pump is input into the cooling passage corresponding to the combustion cylinder of the internal combustion engine, the liquid working medium output by the cooling passage is returned to the catalytic evaporator, and due to the fact that the vapor working medium expands to do work to convert part of heat energy into mechanical energy and output the mechanical energy through the crankshaft, the recycling rate of waste heat of the internal combustion engine is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of internal combustion engine waste heat recovery, in particular to an internal combustion engine waste heat recovery method and system. BACKGROUND

[0002] An internal combustion engine is a heat engine that converts the heat energy released by the combustion of air-fuel mixture into mechanical work. After the fuel is combusted in the cylinder of the internal combustion engine, the exhaust gas is discharged into the atmosphere. The temperature of the exhaust gas is relatively high, and part of the energy is still contained in the exhaust gas. However, when the exhaust gas is directly discharged into the atmosphere, the energy contained in the exhaust gas is wasted.

[0003] Therefore, how to recover and utilize the waste heat after the combustion of the internal combustion engine has become a problem to be solved. SUMMARY

[0004] Therefore, the first aspect of the present application provides an internal combustion engine waste heat recovery method, which comprises:

[0005] inputting the exhaust gas generated in the combustion cylinder of the internal combustion engine into a catalytic evaporator, and heating the first liquid working medium in the catalytic evaporator by using the heat of the exhaust gas;

[0006] controlling the distribution valve to input the gaseous working medium formed by the heating and vaporization of the first liquid working medium in the catalytic evaporator into a working medium expansion cylinder, and inputting the gaseous working medium output by the working medium expansion cylinder into a working medium condenser for cooling to obtain a second liquid working medium; and inputting the second liquid working medium into a first working medium pump;

[0007] controlling the distribution valve to input the first liquid working medium that is not vaporized in the catalytic evaporator into the first working medium pump;

[0008] inputting the liquid working medium in the first working medium pump into the cooling passage corresponding to the combustion cylinder of the internal combustion engine, and returning the third liquid working medium output by the cooling passage to the catalytic evaporator.

[0009] Optionally, the method further comprises:

[0010] detecting the temperature of the third liquid working medium at the output end of the cooling passage, and if the temperature of the third liquid working medium is higher than a preset temperature threshold, opening a shunt valve to input the third liquid working medium into the working medium condenser for cooling.

[0011] Optionally, the inputting of the exhaust gas generated in the combustion cylinder of the internal combustion engine into the catalytic evaporator comprises:

[0012] inputting the exhaust gas output by the combustion cylinder of the internal combustion engine into a turbine of a supercharger, and inputting the exhaust gas discharged by the turbine into the catalytic evaporator.

[0013] Optionally, the inputting the gaseous working medium outputted by the working medium expansion cylinder into a working medium condenser for cooling comprises:

[0014] inputting the gaseous working medium outputted by the working medium expansion cylinder into a regenerator, and outputting the gaseous working medium outputted by the regenerator into the working medium condenser for cooling;

[0015] the returning the third liquid working medium outputted by the cooling passage to the catalytic evaporator comprises:

[0016] inputting the third liquid working medium outputted by the cooling passage into the regenerator, preheating the third liquid working medium by the gaseous working medium in the regenerator, and obtaining a preheated working medium flow;

[0017] outputting the preheated working medium flow from the regenerator to the catalytic evaporator.

[0018] Optionally, the returning the third liquid working medium outputted by the cooling passage to the catalytic evaporator comprises:

[0019] pressurizing the third liquid working medium outputted by the cooling passage, and returning the pressurized third liquid working medium to the catalytic evaporator.

[0020] The second aspect of the present application provides a waste heat recovery system of an internal combustion engine, the system comprising: an internal combustion engine combustion cylinder, a catalytic evaporator, a distribution valve, a working medium expansion cylinder, a working medium condenser, a first working medium pump, and a cooling passage.

[0021] The air inlet end of the internal combustion engine combustion cylinder is in communication with the air outside the system, and the exhaust end of the internal combustion engine combustion cylinder is connected with the catalytic evaporator, for fuel combustion to generate exhaust gas.

[0022] The air inlet end of the catalytic evaporator is connected with the exhaust end of the internal combustion engine combustion cylinder, the input end of the catalytic evaporator is connected with the output end of the cooling passage, the output end of the catalytic evaporator is connected with the input end of the distribution valve, and the catalytic evaporator is used for storing a first liquid working medium and heating the first liquid working medium by the heat of the exhaust gas.

[0023] The input end of the distribution valve is connected with the output end of the catalytic evaporator, the liquid flow output end of the distribution valve is connected with the input end of the first working medium pump, and the gas flow output end of the distribution valve is connected with the input end of the working medium expansion cylinder, and the distribution valve is used for controlling the flow directions of the gaseous working medium and the first liquid working medium.

[0024] The output end of the working medium expansion cylinder is connected with the input end of the working medium condenser, and the working medium expansion cylinder is used for converting the heat energy of the gaseous working medium into mechanical energy;

[0025] The output end of the working medium condenser is connected with the input end of the first working medium pump, and is used for cooling the gaseous working medium to form a second liquid working medium;

[0026] The output end of the first working medium pump is connected with the input end of the cooling passage, and is used for pressurizing the liquid working medium and then introducing the liquid working medium into the cooling passage;

[0027] The cooling passage is used for cooling the internal combustion engine combustion cylinder.

[0028] Optionally, the system further comprises a flow distribution valve;

[0029] The flow distribution valve is installed at the output end of the cooling passage, and when the temperature of the third liquid working medium at the output end of the cooling passage is higher than a preset temperature threshold, the flow distribution valve is used for distributing the third liquid working medium to the working medium condenser.

[0030] Optionally, the system further comprises a supercharger and an intercooler;

[0031] The turbine of the supercharger is installed between the exhaust end of the internal combustion engine combustion cylinder and the gas inlet end of the catalytic evaporator, and the turbine is driven to rotate by the exhaust gas;

[0032] The intercooler is installed at the air inlet end of the internal combustion engine combustion cylinder, and is used for cooling the air input into the internal combustion engine combustion cylinder;

[0033] The compressor wheel of the supercharger is connected with the intercooler, and is used for pressurizing the air input into the internal combustion engine combustion cylinder.

[0034] Optionally, the system further comprises a regenerator;

[0035] The first input end of the regenerator is connected with the output end of the cooling passage, and the first output end of the regenerator is connected with the gas inlet end of the catalytic evaporator;

[0036] The second input end of the regenerator is connected with the output end of the working medium expansion cylinder, and the second output end of the regenerator is connected with the input end of the working medium condenser;

[0037] The regenerator is used for connecting the gaseous working medium output by the working medium expansion cylinder and the third liquid working medium output by the cooling passage, preheating the third liquid working medium by the gaseous working medium, and obtaining a preheated working medium flow.

[0038] Optionally, the system further comprises a second working medium pump;

[0039] The second working medium pump is installed between the output end of the cooling passage and the input end of the catalytic evaporator, for pressurizing the third liquid working medium output by the cooling passage.

[0040] From the above technical solutions, the present application has the following advantages:

[0041] The present application provides an internal combustion engine waste heat recovery method and system, using the working medium stored in the catalytic evaporator as the circulating material, forming the vapor working medium and the first liquid working medium. For the vapor working medium, a gas flow circulation passage is formed, including the catalytic evaporator, the distribution valve, the working medium expansion cylinder, the working medium condenser, and the first working medium pump. For the liquid working medium, a liquid flow circulation passage is formed, including the catalytic evaporator, the distribution valve, the first working medium pump, the cooling passage, and the catalytic evaporator. The exhaust gas output by the internal combustion engine combustion cylinder is input into the catalytic evaporator, and the heat of the exhaust gas is used to heat the first liquid working medium in the catalytic evaporator. Part of the first liquid working medium is vaporized after being heated, forming the vapor working medium. The vapor working medium is distributed by the distribution valve and input into the working medium expansion cylinder of the internal combustion engine, pushing the piston to work and converting the heat energy in the vapor working medium into mechanical energy. After the vapor working medium is output from the working medium expansion cylinder, it is input into the working medium condenser to cool the vapor working medium, making it become liquid again and forming the second liquid working medium which is input into the first working medium pump to continue participating in the liquid flow circulation. The first liquid working medium in the catalytic evaporator which is not vaporized by heating is distributed by the distribution valve and input into the first working medium pump for liquid flow circulation. The first working medium pump saves the liquid working medium from the working medium condenser and / or from the catalytic evaporator. All the liquid working medium in the first working medium pump is input into the cooling passage of the internal combustion engine combustion cylinder. When the temperature of the internal combustion engine combustion cylinder is high, the liquid working medium can cool the internal combustion engine combustion cylinder. During the cooling process, the liquid working medium can absorb the heat of the internal combustion engine combustion cylinder again, realizing the secondary heating of the liquid working medium. The third liquid working medium output after the secondary heating is returned to the catalytic evaporator, and the vapor working medium formed by the heating and vaporization increases. Therefore, the vapor working medium input into the working medium expansion cylinder also increases, and the mechanical energy converted in the working medium expansion cylinder increases. The internal combustion engine waste heat recovery rate is improved, and the heat recovery rate of the internal combustion engine combustion cylinder is also improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A method flowchart of an internal combustion engine waste heat recovery method provided by the present application embodiment;

[0043] Figure 2 A structure schematic diagram of an internal combustion engine waste heat recovery system provided by the present application embodiment;

[0044] Figure 3A structural schematic diagram of an internal combustion engine waste heat recovery system according to another embodiment of the present application is provided. DETAILED DESCRIPTION

[0045] Embodiments of the present application will be described in more detail with reference to the drawings. Although some embodiments of the present application are shown in the drawings, it is understood that the present application can be implemented in various forms and should not be interpreted as being limited to the embodiments set forth herein, but rather these embodiments are provided so that the present application can be more thoroughly and completely understood. It should be understood that the drawings and embodiments of the present application are only for illustrative purposes and are not intended to limit the scope of protection of the present application.

[0046] The term "comprising" and variations thereof as used herein are open-ended, that is "including but not limited to". The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment". The term "another embodiment" means "at least one additional embodiment". The term "some embodiments" means "at least some embodiments". Related terms are defined as follows.

[0047] It should be noted that the terms "first", "second", and the like in the present application are only used to distinguish different devices, modules or units, and are not intended to limit the order or interdependence of the functions performed by these devices, modules or units.

[0048] It should be noted that the terms "one", "multiple" in the present application are illustrative and not restrictive, and those skilled in the art should understand that unless otherwise explicitly stated in the context, it should be understood as "one or more".

[0049] Reference is made to Figure 1 , Figure 1 A method flowchart of an internal combustion engine waste heat recovery method according to an embodiment of the present application is provided, which specifically includes the following steps:

[0050] Step 101: input the exhaust gas generated in the internal combustion engine combustion cylinder into the catalytic evaporator, and use the heat of the exhaust gas to heat the first liquid working medium in the catalytic evaporator.

[0051] After the fuel in the internal combustion engine combustion cylinder is burned, exhaust gas is emitted into the atmosphere. The exhaust gas generated by the combustion of the internal combustion engine combustion cylinder is referred to as exhaust gas in the present application. Since the combustion temperature in the internal combustion engine combustion cylinder is high, the temperature of the exhaust gas output from the internal combustion engine combustion cylinder is also high. In order to recover the heat stored in the exhaust gas, the exhaust gas is first input into the catalytic evaporator before being discharged into the atmosphere, and the heat of the exhaust gas is used to heat the first liquid working medium in the catalytic evaporator. After the first liquid working medium is heated, part of the first liquid working medium will vaporize to form a vapor working medium, while the remaining first liquid working medium remains in liquid state.

[0052] It should be noted that in the embodiments of the present application, the gaseous working medium and the first liquid working medium are two different forms of the same substance.

[0053] In the embodiments of the present application, the first liquid working medium can be any one of an organic substance, an inorganic substance, and a mixture of an organic substance and an inorganic substance. For example, the inorganic substance includes but is not limited to water, ammonia, and the like, and the organic substance includes but is not limited to ethanol, refrigerant R134, and the like.

[0054] In a possible implementation, inputting the exhaust gas generated by the combustion cylinder of the internal combustion engine into the catalytic evaporator can be implemented in the following manner:

[0055] The exhaust gas output by the combustion cylinder of the internal combustion engine is input into the turbine of the supercharger, and the exhaust gas discharged from the turbine is input into the catalytic evaporator.

[0056] The supercharger is an air compressor that increases the intake amount of the combustion cylinder of the internal combustion engine. When the exhaust gas generated by the combustion cylinder of the internal combustion engine is input into the turbine of the supercharger, the turbine is driven to rotate by the inertial impact force of the exhaust gas, and then the supercharger is driven to rotate by the turbine. After the supercharger rotates, the intake end of the combustion cylinder of the internal combustion engine is pressurized, the air at the intake end is compressed, and the intake amount of the intake end of the combustion cylinder of the internal combustion engine is increased.

[0057] For the turbine of the supercharger, after the turbine is driven to rotate by the inertial impact force of the exhaust gas, the exhaust gas continues to be input into the catalytic evaporator in the original flow direction. Thus, the energy in the exhaust gas is utilized once before the exhaust gas enters the catalytic evaporator.

[0058] Step 102: controlling the distribution valve to input the gaseous working medium formed by heating and vaporizing the first liquid working medium in the catalytic evaporator into the working medium expansion cylinder, input the gaseous working medium output by the working medium expansion cylinder into the working medium condenser for cooling to obtain second liquid working medium, and input the second liquid working medium into the first working medium pump.

[0059] In the embodiments of the present application, the distribution valve is used to distribute the working medium in different states in the catalytic evaporator to different circulation paths for utilization.

[0060] For the first liquid working medium heated and vaporized in the catalytic evaporator, the vapor working medium is formed. The state of the working medium in the catalytic evaporator is detected, and the vapor working medium is output to the working medium expansion cylinder through the distribution valve. In the working medium expansion cylinder, the piston in the cylinder is driven by the pressure of the vapor working medium to do work and generate mechanical energy, realizing the utilization of the heat energy in the vapor working medium and converting the heat energy in the vapor working medium into mechanical energy. At this time, the heat in the exhaust gas is absorbed by the first liquid working medium, part of which is converted into heat energy in the vapor working medium, and the heat energy in the vapor working medium is utilized in the working medium expansion cylinder and converted into mechanical energy, realizing the recycling of the heat energy in the exhaust gas of the internal combustion engine.

[0061] After the vapor working medium does work in the working medium expansion cylinder, it is output and then input to the working medium condenser. The working medium condenser provides a low-temperature environment to cool the vapor working medium into a liquid to obtain the second liquid working medium, which is input to the first working medium pump. In the embodiment of the present application, the second liquid working medium is also the liquid state corresponding to the vapor working medium, which is essentially the same as the first liquid working medium, and both are liquid working media.

[0062] For the vapor working medium generated by vaporization in the catalytic evaporator, the vapor working medium is converted into a liquid after doing work in the working medium expansion cylinder, and participates in the circulation of the liquid working medium again in the form of the second liquid working medium. That is, for the vapor working medium, it is utilized in two states, not only to drive the piston in the working medium expansion cylinder to do work, but also to participate in the circulation of the liquid working medium.

[0063] In the embodiment of the present application, the mechanical energy generated in the working medium expansion cylinder and the internal combustion engine combustion cylinder is output to the outside through the crankshaft of the internal combustion engine to provide power for vehicle driving.

[0064] Step 103: controlling the distribution valve to input the first liquid working medium that is not vaporized in the catalytic evaporator to the first working medium pump.

[0065] And for the first liquid working medium that is not vaporized in the catalytic evaporator, it is output to the first working medium pump.

[0066] Step 104: inputting the liquid working medium in the first working medium pump to the cooling passage corresponding to the internal combustion engine combustion cylinder, and returning the third liquid working medium output by the cooling passage to the catalytic evaporator.

[0067] The liquid working medium stored in the first working medium pump can only include the first liquid working medium obtained from the catalytic evaporator when the temperature in the catalytic evaporator is not high enough and no working medium is vaporized; the liquid working medium stored in the first working medium pump can only include the second liquid working medium obtained from the working medium condenser when the temperature in the catalytic evaporator is too high and all the first liquid working medium is vaporized; and the liquid working medium stored in the first working medium pump can include both the second liquid working medium and the first liquid working medium when the catalytic evaporator is in a state of partial vaporization of the first liquid working medium.

[0068] The cooling passage is a loop distributed around the combustion cylinder of the internal combustion engine. Since the cooling passage is arranged at different positions, the liquid working medium stored in the cooling passage can be pressurized by the first working medium pump and pumped into the cooling passage. When the temperature of the combustion cylinder of the internal combustion engine is too high after combustion, the liquid working medium can be used to cool the combustion cylinder and the cylinder head. In this process, the heat energy generated by combustion in the combustion cylinder of the internal combustion engine can be recycled, and the liquid working medium can be heated again by absorbing the heat of the combustion cylinder of the internal combustion engine. That is, in the circulation passage of the liquid working medium, the catalytic evaporator-distribution valve-first working medium pump-cooling passage-catalytic evaporator, the liquid working medium can be heated in the catalytic evaporator and in the cooling passage. When the third liquid working medium in the cooling passage is returned to the catalytic evaporator, more first liquid working medium can be vaporized to obtain more gaseous working medium, and more gaseous working medium can enter the working medium expansion cylinder to do work and convert more mechanical energy. In this way, the waste heat in the combustion cylinder and exhaust gas of the internal combustion engine can be recycled. In the embodiments of the present application, not only the heat in the exhaust gas of the internal combustion engine can be used, but also the heat in the combustion cylinder of the internal combustion engine can be used, thereby improving the recycling rate of the waste heat of the internal combustion engine.

[0069] In a possible implementation, the method can further include:

[0070] The temperature of the third liquid working medium at the output end of the cooling passage is detected, and if the temperature of the third liquid working medium is higher than a preset temperature threshold, a shunt valve is opened to input the third liquid working medium into the working medium condenser for cooling.

[0071] At the output end of the cooling passage of the combustion cylinder of the internal combustion engine, the temperature of the third liquid working medium about to be output by the cooling passage is detected. When the temperature of the third liquid working medium is higher than the preset temperature threshold and the required cooling liquid flow in the cooling passage of the combustion cylinder of the internal combustion engine is large, since the temperature of the third liquid working medium is high, if the third liquid working medium is returned to the catalytic evaporator again for heating, more liquid working medium will be vaporized to gaseous working medium, resulting in a decrease in the liquid working medium flowing in the whole waste heat recovery cycle, which cannot meet the demand of the cooling liquid flow in the cooling passage. In addition, since the temperature of the third liquid working medium is high, if the third liquid working medium is directly returned to the catalytic evaporator for heating, the temperature of the liquid working medium output from the catalytic evaporator to the first working medium pump will be higher, and when the first working medium pump pumps the liquid working medium into the cooling passage, the liquid working medium with the excessively high temperature cannot cool the combustion cylinder of the internal combustion engine.

[0072] Therefore, when the temperature of the third liquid working medium detected at the output end of the cooling passage is higher than the preset temperature threshold, the control device controls the diversion valve installed at the output end of the cooling passage to open, so that the third liquid working medium with the high temperature is input into the working medium condenser for cooling to obtain the second liquid working medium. In this way, the temperature of the liquid flow is reduced, and when the first working medium pump inputs the liquid flow stored therein into the cooling passage again, the liquid flow can cool the combustion cylinder of the internal combustion engine, thereby realizing the cyclic cooling of the combustion cylinder of the internal combustion engine.

[0073] It should be noted that in the embodiments of the present application, the cooling liquid flow is the liquid working medium input into the cooling passage by the first working medium pump for cooling the combustion cylinder of the internal combustion engine.

[0074] As an embodiment, when the gaseous working medium output from the working medium expansion cylinder is input into the working medium condenser for cooling, the following method can be used:

[0075] The gaseous working medium output from the working medium expansion cylinder is input into the regenerator, and the gaseous working medium output from the regenerator is output to the working medium condenser for cooling;

[0076] At this time, when the third liquid working medium output from the cooling passage is returned to the catalytic evaporator, the following method can be used:

[0077] The third liquid working medium output from the cooling passage is input into the regenerator, the third liquid working medium is preheated by the gaseous working medium in the regenerator to obtain a preheated working medium flow;

[0078] The preheated working medium flow is output from the regenerator to the catalytic evaporator.

[0079] When the gaseous working medium is discharged from the working medium expansion cylinder, the temperature is still high. In order to further utilize the waste heat of the gaseous working medium, a regenerator can be installed at the outlet of the working medium expansion cylinder, and the regenerator is also connected with the output end of the cooling channel. The gaseous working medium discharged from the working medium expansion cylinder and the third liquid working medium discharged from the cooling channel converge in the regenerator, and the third liquid working medium is heated by the waste heat of the gaseous working medium, so that the third liquid working medium is preheated before returning to the catalytic evaporator. In this way, more liquid working medium can be vaporized in the catalytic evaporator to obtain more gaseous working medium, thereby increasing the gaseous working medium input into the working medium expansion cylinder and increasing the mechanical energy converted in the working medium expansion cylinder.

[0080] When the third liquid working medium is preheated in the regenerator, part of the liquid working medium may be vaporized by heat and become gaseous working medium. Therefore, the working medium returned from the regenerator to the catalytic evaporator may include both liquid working medium and gaseous working medium, which is referred to as preheated working medium flow in the embodiments of the present application.

[0081] In a possible implementation, when the third liquid working medium output by the cooling channel is returned to the catalytic evaporator, the following method can be used:

[0082] The third liquid working medium output by the cooling channel is pressurized, and the pressurized third liquid working medium is returned to the catalytic evaporator.

[0083] Before the third liquid working medium is returned to the catalytic evaporator, the third liquid working medium can be pressurized by a second working medium pump, and then the pressurized third liquid working medium is returned to the catalytic evaporator. The efficiency of the second working medium pump in pressurizing a liquid flow is higher than that in pressurizing a gas flow. When the second working medium pump is used to pressurize the third liquid working medium, the pressure of the gas in the third liquid working medium will also increase, thereby increasing the gas pressure in the entire circulation loop. Therefore, the pressure of the gaseous working medium input into the working medium expansion cylinder is also increased, so that the work done by the gaseous working medium in the working medium expansion cylinder is increased, and the mechanical energy generated by utilizing the waste heat of the internal combustion engine is also increased.

[0084] In a possible implementation, the system for implementing the internal combustion engine waste heat recovery method provided in the embodiments of the present application can further be provided with an expansion pot. The air in the cooling passage can be discharged into the expansion pot through the expansion pot. When there is no air in the cooling passage, the liquid working medium in the cooling passage can also be discharged into the expansion pot. The lower part of the expansion pot is communicated with the first working medium pump. The circulation between the expansion pot and the first working medium pump can be controlled by the diameter of the connecting pipe of the expansion pot. Generally, the diameter of the connecting pipe of the expansion pot is small. In the cooling circuit, the air is lighter than the working medium, and the air exists in the upper part of the expansion pot. When the working medium in the cooling circuit is heated and vaporized, the gas increases, which can cause the pressure of the expansion pot to be greater than the set value of the safety valve at the top of the expansion pot. At this time, the safety valve at the top of the expansion pot automatically opens to release pressure.

[0085] The substance stored in the expansion pot at least includes the liquid working medium and can further include part of the air. In the entire circulation passage for recycling the waste heat of the internal combustion engine, a certain amount of air can exist. When the pressure in the cooling passage of the internal combustion engine is too large, the air can be discharged from the cooling passage to the expansion pot. When the pressure in the expansion pot is too large, the pressure release valve of the expansion pot can be opened to release the pressure. Since the cooling passage is a complex circulation passage around the combustion cylinder of the internal combustion engine, when the air exists therein, the air can gather at the physically highest part of the cooling passage based on the state of the air and the liquid working medium. Therefore, an air outlet can be arranged at the physically highest part of the cooling passage for discharging the air.

[0086] Although the operations are depicted in a particular order, this should not be understood as requiring the operations to be performed in the particular order shown or in sequential order, and that certain operations can be performed in parallel or in different order than shown.

[0087] It should be understood that each of the steps recited in the method embodiments of the present application can be performed in different order and / or in parallel. In addition, the method embodiments can include additional steps and / or omit the execution of the steps shown. The scope of the present application is not limited in this respect.

[0088] Reference is made to Figure 2 , Figure 2 A structural schematic diagram of an internal combustion engine waste heat recovery system provided in the embodiments of the present application. The system can be used to perform the internal combustion engine waste heat recovery method described in the embodiments of the present application. Figure 1 The system mainly includes: an internal combustion engine combustion cylinder 201, a catalytic evaporator 202, a distribution valve 203, a working medium expansion cylinder 204, a working medium condenser 205, a first working medium pump 206, and a cooling passage 207.

[0089] The intake end of the combustion cylinder of the internal combustion engine is in communication with air outside the system, and the exhaust end of the combustion cylinder of the internal combustion engine is connected to the catalytic evaporator for fuel combustion to generate exhaust gas.

[0090] In Figure 2 , the connection ports of the combustion cylinder of the internal combustion engine to other components include an intake end and an exhaust end. According to the direction of intake flow, external air is input into the combustion cylinder of the internal combustion engine through the intake end of the combustion cylinder of the internal combustion engine; according to the direction of exhaust gas, the exhaust gas generated by combustion of the combustion cylinder of the internal combustion engine is discharged from the exhaust end of the combustion cylinder of the internal combustion engine. Since the exhaust end of the combustion cylinder of the internal combustion engine is connected to the intake end of the catalytic evaporator, the exhaust gas is discharged from the exhaust end of the combustion cylinder of the internal combustion engine and enters the catalytic evaporator. In addition, the catalytic evaporator catalytically converts harmful gases in the received exhaust gas into harmless gases, and the catalytically converted exhaust gas is discharged to the muffler through the second end of the catalytic evaporator.

[0091] The intake end of the catalytic evaporator is connected to the exhaust end of the combustion cylinder of the internal combustion engine, the input end of the catalytic evaporator is connected to the output end of the cooling passage, and the output end of the catalytic evaporator is connected to the input end of the distribution valve. The catalytic evaporator is used to store the first liquid working medium and heat the first liquid working medium by using the heat of the exhaust gas.

[0092] In Figure 2 , the connection ports of the catalytic evaporator to other components include a first end, an input end, and an output end. Among them, the intake end of the catalytic evaporator is connected to the exhaust end of the combustion cylinder of the internal combustion engine, the input end of the catalytic evaporator is connected to the output end of the cooling passage, and the output end of the catalytic evaporator is connected to the input end of the distribution valve. After the exhaust gas enters the catalytic evaporator through the intake end of the catalytic evaporator, it heats the first liquid working medium in the catalytic evaporator, and the generated vapor working medium and liquid working medium are output through the output end of the catalytic evaporator.

[0093] In the catalytic evaporator, since the vapor working medium and the liquid working medium may exist at the same time, in Figure 2 , the working medium state in the catalytic evaporator is recorded as a mixed state working medium.

[0094] The input end of the distribution valve is connected to the output end of the catalytic evaporator, the liquid flow output end of the distribution valve is connected to the input end of the first working medium pump, and the gas flow output end of the distribution valve is connected to the input end of the working medium expansion cylinder. The distribution valve is used to control the flow direction of the vapor working medium and the first liquid working medium.

[0095] As Figure 2As shown, a distribution valve is installed at the output end of the catalytic evaporator, and the flow direction of the working medium distributed by the distribution valve is controlled by judging the state of the output working medium. The ports of the distribution valve connected with other components include an input end, a liquid flow output end, and a gas flow output end. The input end is connected with the output end of the catalytic evaporator to receive the liquid working medium and the gaseous working medium from the catalytic evaporator. The liquid flow output end is connected with the first working medium pump to distribute the liquid working medium from the catalytic evaporator to the first working medium pump. The gas flow output end is connected with the input end of the working medium expansion cylinder to distribute the gaseous working medium from the catalytic evaporator to the working medium expansion cylinder. The flow direction of the working medium can be controlled according to the state of the working medium through the distribution valve.

[0096] The output end of the working medium expansion cylinder is connected with the input end of the working medium condenser, and the working medium expansion cylinder is used to convert the heat energy of the gaseous working medium into mechanical energy.

[0097] In the embodiment, the ports of the working medium expansion cylinder connected with other components include an input end and an output end. The input end of the working medium expansion cylinder is connected with the gas flow output end of the distribution valve to receive the gaseous working medium from the catalytic evaporator. The output end of the working medium expansion cylinder is connected with the input end of the working medium condenser. Figure 2 The output end of the working medium condenser is connected with the input end of the first working medium pump to cool the gaseous working medium to form the second liquid working medium.

[0098] In the embodiment, the ports of the working medium condenser connected with other components include an input end and an output end. The input end of the working medium condenser is connected with the output end of the working medium expansion cylinder, and the output end of the working medium condenser is connected with the input end of the first working medium pump. The gaseous working medium output from the working medium expansion cylinder is cooled to the liquid state in the working medium condenser to form the second liquid working medium input into the first working medium pump.

[0099] Figure 2 The output end of the first working medium pump is connected with the input end of the cooling passage to pressurize the liquid working medium and then guide the liquid working medium into the cooling passage.

[0100] In the embodiment, the ports of the first working medium pump connected with other components include an input end and an output end. The input end of the first working medium pump is connected with the liquid flow output end of the distribution valve, and the input end of the first working medium pump is also connected with the output end of the working medium condenser. The output end of the first working medium pump is connected with the input end of the cooling passage. The liquid working medium from the working medium condenser and / or from the catalytic evaporator is input into the first working medium pump to form a cooling liquid flow, which is pumped into the cooling passage by the first working medium pump.

[0101] The cooling passage is used to cool the combustion cylinder of the internal combustion engine. Figure 2 The cooling passage is used to cool the combustion cylinder of the internal combustion engine.

[0102] The cooling passage is used to cool the combustion cylinder of the internal combustion engine.

[0103] ​The connection ports of the cooling passage and other components include an input end and an output end, wherein the input end of the cooling passage is connected with the output end of the first working medium pump, and the output end of the cooling passage is connected with the input end of the catalytic evaporator. The catalytic evaporator is a circulation passage arranged around the combustion cylinder of the internal combustion engine in the structure of the internal combustion engine. The liquid working medium in the cooling passage can absorb the waste heat of the combustion cylinder of the internal combustion engine, thereby cooling the combustion cylinder of the internal combustion engine.

[0104] It should be understood that, in the embodiments of the present application, the connection mode between different component connection ports can be direct connection or indirect connection, wherein the indirect connection includes but is not limited to connection through a pipe. For the connection concept described in the embodiments of the present application, an exemplary expression is as follows: when the substance is discharged from the a port of the A component and can directly enter the b port of the B component, it is said that the a port of the A component is connected with the b port of the B component; if the substance is discharged from the a port of the A component and can enter both the b port of the B component and the c port of the C component, it is said that the a port of the A component is connected with the b port of the B component, and the a port of the A component is also connected with the c port of the C component. The present application does not limit the connection mode between each connection port.

[0105] Based on the above-described internal combustion engine waste heat recovery system, it can be seen that, for the first liquid working medium in the catalytic evaporator, the corresponding circulation passage is: catalytic evaporator-distribution valve-first working medium pump-cooling passage-catalytic evaporator. In this liquid flow circulation passage, the liquid working medium can be cyclically heated in the catalytic evaporator and the cooling passage to absorb the waste heat of the internal combustion engine exhaust gas and the combustion cylinder of the internal combustion engine. For the gaseous working medium in the catalytic evaporator, the corresponding gas flow circulation passage is: catalytic evaporator-distribution valve-working medium expansion cylinder-working medium condenser-first working medium pump-cooling passage-catalytic evaporator. The gaseous working medium formed by the heating and vaporization of the working medium can be restored to a liquid state through the working medium condenser after doing work in the working medium expansion cylinder to continue to absorb the waste heat of the combustion cylinder of the internal combustion engine, thereby realizing the heat absorption, vaporization, work, heat absorption... working medium energy utilization cycle, and further realizing the recovery and utilization of the waste heat of the internal combustion engine.

[0106] The present application Figure 2 The internal combustion engine waste heat recovery system provided can convert the waste heat of the combustion cylinder of the internal combustion engine and the waste heat of the exhaust gas into useful work and output through the crankshaft of the internal combustion engine, thereby not only improving the recovery and utilization of the waste heat of the internal combustion engine, but also, compared with the Rankine cycle system, the internal combustion engine waste heat recovery system provided by the present application does not need to be provided with a separate expander, a generator and a transmission system, has a more compact structure, occupies less space and meets the integration requirements of a vehicle.

[0107] Referring to Figure 3 , Figure 3The structure schematic diagram of the internal combustion engine waste heat recovery system provided for another embodiment of the present application adds: a flow divider 208, a supercharger 209, an intercooler 210, a cooling fan 211, a regenerator 212, an expansion pot 213, an air filter 214, a muffler 215, and a second working medium pump 216, compared with the system shown in Figure 2 , Figure 3

[0108] In a possible implementation manner, the system further comprises a flow divider.

[0109] The flow divider is installed at the output end of the cooling passage, and when the third liquid working medium temperature at the output end of the cooling passage is higher than a preset temperature threshold, the third liquid working medium temperature is diverted to the working medium condenser through the flow divider.

[0110] The connection ports of the flow divider and other components include an input end and an output end, wherein the input end of the flow divider is connected with the output end of the cooling passage, and the output end of the flow divider is connected with the input end of the working medium condenser.

[0111] In a possible implementation manner, the system further comprises a supercharger and an intercooler.

[0112] The turbine of the supercharger is installed between the exhaust end of the internal combustion engine combustion cylinder and the gas inlet end of the catalytic evaporator, and the turbine is driven to rotate by the exhaust gas.

[0113] The intercooler is installed at the gas inlet end of the internal combustion engine combustion cylinder, and is used for cooling the air input into the internal combustion engine combustion cylinder.

[0114] The compression wheel of the supercharger is connected with the intercooler, and is used for pressurizing the air input into the internal combustion engine combustion cylinder.

[0115] In a possible implementation manner, the system further comprises a regenerator.

[0116] The first input end of the regenerator is connected with the output end of the cooling passage, and the first output end of the regenerator is connected with the gas inlet end of the catalytic evaporator.

[0117] The second input end of the regenerator is connected with the output end of the working medium expansion cylinder, and the second output end of the regenerator is connected with the input end of the working medium condenser.

[0118] The regenerator is used for connecting the gaseous working medium output by the working medium expansion cylinder and the third liquid working medium output by the cooling passage, preheating the third liquid working medium by the gaseous working medium, and obtaining a preheated working medium flow.

[0119] In a possible implementation manner, the system further comprises a second working medium pump.​

[0120] The second working medium pump is installed between the output end of the cooling channel and the input end of the catalytic evaporator, and is used for pressurizing the third liquid working medium output from the cooling channel.

[0121] In Figure 3 , it can be seen that when the second working medium pump and the regenerator are installed in the system at the same time, the input end of the second working medium pump is connected with the output end of the cooling channel, and the output end of the second working medium pump is connected with the input end of the catalytic evaporator through the regenerator. Specifically, the output end of the second working medium pump is connected with the first input end of the regenerator, and is used for pressurizing the third liquid working medium output from the cooling channel.

[0122] In a possible implementation, the system further comprises an expansion tank;

[0123] The air in the cooling channel can be discharged into the expansion tank through the expansion tank, and when there is no air in the cooling channel, the liquid working medium in the cooling channel can also be discharged into the expansion tank. The lower part of the expansion tank is connected with the first working medium pump, and circulation exists in the expansion tank and the first working medium pump, which can be controlled by the diameter of the connecting pipe of the expansion tank. Generally, the diameter of the connecting pipe of the expansion tank is small. In the cooling circuit, the air is lighter than the working medium, so the air exists in the upper part of the expansion tank. When the working medium in the cooling circuit is heated and vaporized, the gas increases, which can cause the pressure of the expansion tank to be greater than the set value of the safety valve at the top of the expansion tank. At this time, the safety valve at the top of the expansion tank automatically opens to release pressure.

[0124] In a possible implementation, the system further comprises a heat dissipation fan; the heat dissipation fan is connected with the working medium condenser, and is used for cooling the working medium input into the working medium condenser.

[0125] It should be noted that the number of combustion cylinders of the internal combustion engine in the embodiments of the present application can be one or more, and the number of working medium expansion cylinders can be one or more. The working medium expansion cylinder can be one or more of the internal combustion engine cylinders.

[0126] In addition, Figure 3 The air filter in the internal combustion engine is used for filtering impurities in the air entering the combustion cylinder of the internal combustion engine, and the muffler is used for reducing the noise of exhaust emission.

[0127] The names of the messages or information exchanged between the plurality of devices in the embodiments of the present application are only used for illustrative purposes, and are not used to limit the scope of the messages or information.

[0128] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described herein.

[0129] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the division of the above-described device embodiments is only a logical function division, and there can be another division manner for actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, or the among different units, can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0130] The units described as separated components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments of the present application.

[0131] In addition, each functional unit in the embodiments of the present application can be integrated in a processing unit, or each unit can exist physically as a separate unit, or two or more units can be integrated in one unit. The integrated unit can be implemented in the form of hardware, or in the form of a software functional unit.

[0132] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An internal combustion engine waste heat recovery method characterized by, The method comprises: inputting exhaust gas generated in an internal combustion engine combustion cylinder into a catalytic evaporator, and heating a first liquid working medium in the catalytic evaporator by using heat of the exhaust gas; controlling a distribution valve to input a gaseous working medium formed by heating and vaporization of the first liquid working medium in the catalytic evaporator into a working medium expansion cylinder, and inputting the gaseous working medium output by the working medium expansion cylinder into a working medium condenser to be cooled to obtain a second liquid working medium; and inputting the second liquid working medium into a first working medium pump; controlling the distribution valve to input the first liquid working medium that is not vaporized in the catalytic evaporator into the first working medium pump; inputting the liquid working medium in the first working medium pump into a cooling passage corresponding to the internal combustion engine combustion cylinder, and returning third liquid working medium output by the cooling passage to the catalytic evaporator.

2. The method of claim 1, wherein, The method further comprises: detecting a temperature of the third liquid working medium at an output end of the cooling passage, and if the temperature of the third liquid working medium is higher than a preset temperature threshold, opening a shunt valve to input the third liquid working medium into the working medium condenser to be cooled.

3. The method of claim 1, wherein, The inputting of the exhaust gas generated in the internal combustion engine combustion cylinder into the catalytic evaporator comprises: inputting the exhaust gas output by the internal combustion engine combustion cylinder into a turbine of a supercharger, and inputting the exhaust gas discharged by the turbine into the catalytic evaporator.

4. The method of claim 1, wherein, The inputting of the gaseous working medium output by the working medium expansion cylinder into the working medium condenser to be cooled comprises: inputting the gaseous working medium output by the working medium expansion cylinder into a regenerator, and outputting the gaseous working medium output by the regenerator to the working medium condenser to be cooled. The returning of the third liquid working medium output by the cooling passage to the catalytic evaporator comprises: inputting the third liquid working medium output by the cooling passage into the regenerator, preheating the third liquid working medium by using the gaseous working medium in the regenerator to obtain a preheated working medium flow; and outputting the preheated working medium flow from the regenerator to the catalytic evaporator. The returning of the third liquid working medium output by the cooling passage to the catalytic evaporator comprises:

5. The method of claim 1, wherein, pressurizing the third liquid working medium output by the cooling passage, and returning the pressurized third liquid working medium to the catalytic evaporator. The system comprises an internal combustion engine combustion cylinder, a catalytic evaporator, a distribution valve, a working medium expansion cylinder, a working medium condenser, a first working medium pump, and a cooling passage.

6. An internal combustion engine waste heat recovery system characterized by comprising: An air inlet end of the internal combustion engine combustion cylinder is connected with the outside air, and an exhaust end of the internal combustion engine combustion cylinder is connected with the catalytic evaporator to generate exhaust gas by fuel combustion. An air inlet end of the catalytic evaporator is connected with the exhaust end of the internal combustion engine combustion cylinder, an input end of the catalytic evaporator is connected with an output end of the cooling passage, and an output end of the catalytic evaporator is connected with an input end of the distribution valve, the catalytic evaporator is used to store a first liquid working medium and heat the first liquid working medium by using heat of the exhaust gas. ​ The input end of the distribution valve is connected with the output end of the catalytic evaporator, the liquid flow output end of the distribution valve is connected with the input end of the first working medium pump, and the gas flow output end of the distribution valve is connected with the input end of the working medium expansion cylinder, and the distribution valve is used for controlling the flow directions of the gaseous working medium and the first liquid working medium. The output end of the working medium expansion cylinder is connected with the input end of the working medium condenser, and the working medium expansion cylinder is used for converting thermal energy of the gaseous working medium into mechanical energy. The output end of the working medium condenser is connected with the input end of the first working medium pump, and the working medium condenser is used for cooling the gaseous working medium to form second liquid working medium. The output end of the first working medium pump is connected with the input end of the cooling channel, and the first working medium pump is used for pressurizing the liquid working medium and then introducing the liquid working medium into the cooling channel. The cooling channel is used for cooling the internal combustion engine combustion cylinder.

7. The system of claim 6, wherein, The system further comprises a distribution valve. The distribution valve is installed at the output end of the cooling channel, and when the temperature of the third liquid working medium at the output end of the cooling channel is higher than a preset temperature threshold, the distribution valve is used for distributing the third liquid working medium to the working medium condenser.

8. The system of claim 6, wherein, The system further comprises a supercharger and an intercooler. A turbine of the supercharger is installed between the exhaust end of the internal combustion engine combustion cylinder and the air inlet end of the catalytic evaporator, and the turbine is driven to rotate by the exhaust gas. The intercooler is installed at the air inlet end of the internal combustion engine combustion cylinder, and is used for cooling air input into the internal combustion engine combustion cylinder. A compressor wheel of the supercharger is connected with the intercooler, and is used for pressurizing the air input into the internal combustion engine combustion cylinder.

9. The system of claim 6, wherein, The system further comprises a regenerator. A first input end of the regenerator is connected with the output end of the cooling channel, and a first output end of the regenerator is connected with the input end of the catalytic evaporator. A second input end of the regenerator is connected with the output end of the working medium expansion cylinder, and a second output end of the regenerator is connected with the input end of the working medium condenser. The regenerator is used for connecting the gaseous working medium output by the working medium expansion cylinder and the third liquid working medium output by the cooling channel, preheating the third liquid working medium by the gaseous working medium, and obtaining preheated working medium flow.

10. The system of claim 1, wherein, The system further comprises a second working medium pump. The second working medium pump is installed between the output end of the cooling channel and the input end of the catalytic evaporator, and is used for pressurizing the third liquid working medium output by the cooling channel.

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