Waste heat utilization system of internal combustion engine
Technical Field
The invention relates to the technical field of energy utilization, in particular to an internal combustion engine waste heat utilization system.
Background
An internal combustion engine is an important power machine, and is a heat engine that directly converts heat energy emitted from a fuel burned in the machine into power, and is widely used in engineering practice.
In operation of an internal combustion engine, a large amount of heat is dissipated to the outside in the form of exhaust gas and water. In order to save energy, the energy contained in the discharged exhaust gas and the discharged water is usually recycled, and according to the traditional treatment mode, the exhaust gas and the discharged water discharged by the internal combustion engine are usually directly utilized for heat supply, and the exhaust gas waste heat temperature of the internal combustion engine is higher, if the heat supply is directly utilized for heat supply, a lot of high-grade energy is not effectively utilized and is converted into low-grade energy, so that the systemThe efficiency is low. Wherein (1)>Efficiency is understood as->The proportion of the total energy of the system, in particular, the part of the energy which can theoretically be converted into any other energy form in total when the system is reversibly changed from any state to a state in equilibrium with a given environment, is called->Namely +.>Efficiency is improved.
Disclosure of Invention
The embodiment of the invention aims to provide an internal combustion engine waste heat utilization system which fully utilizes high-grade energy of waste heat of an internal combustion engine and improves the internal combustion engine systemEfficiency is improved.
The embodiment of the invention provides an internal combustion engine waste heat utilization system, which comprises an internal combustion engine, an organic Rankine cycle system and a second type of heat pump, wherein:
the internal combustion engine comprises a water outlet and a first air outlet; the organic Rankine cycle system comprises a first air inlet, a second air outlet and a power output part; the second type of heat pump comprises a water inlet and a second air inlet;
the first exhaust port of the internal combustion engine is connected with the first air inlet of the organic Rankine cycle system through a pipeline, and the water outlet of the internal combustion engine is connected with the water inlet of the second-class heat pump through a pipeline; the second exhaust port of the organic Rankine cycle system is connected with the second air inlet of the second type heat pump through a pipeline.
Specifically, the internal combustion engine is a power generation internal combustion engine, and the power generation internal combustion engine is in power connection with the first power generator.
Specifically, the organic rankine cycle system includes a first heat exchanger, a turbine, a regenerator, a first condenser, and a first booster pump, wherein:
the outlet of the heating part of the first heat exchanger, the heat release part of the turbine and the heat regenerator, the first condenser, the first booster pump, the heat absorption part of the heat regenerator and the inlet of the heating part of the first heat exchanger are sequentially connected through an organic working medium pipeline to form an organic circulation loop; the inlet of the cooling part of the first heat exchanger is connected with the first exhaust port of the internal combustion engine through a pipeline, the outlet of the cooling part of the first heat exchanger is connected with the second air inlet of the second type heat pump through a pipeline, and the power output part is a power output shaft of the turbine.
Preferably, the power output unit is in power connection with the second generator.
Alternatively, the organic working medium comprises n-pentane, cyclohexane, toluene, dodecane, or decane.
Specifically, the second type heat pump comprises an evaporator, a generator, a second heat exchanger, a second condenser, a second booster pump and an absorber, wherein:
an inlet of the heat release part of the generator is connected with a second exhaust port of the organic Rankine cycle system through a pipeline; the first outlet of the heat absorption part of the generator, the heating part of the second heat exchanger, the heat release part of the absorber, the cooling part of the second heat exchanger and the inlet of the heat absorption part of the generator are connected through a refrigerant pipeline in sequence to form a refrigerant circulation loop;
an inlet of the heat release part of the evaporator is connected with a second exhaust port of the organic Rankine cycle system through a pipeline;
the second outlet of the heat absorption part of the generator, the second condenser, the second booster pump, the heat absorption part of the evaporator and the heat release part of the absorber are connected through pipelines;
the inlet of the heat absorbing part of the absorber is connected with the water outlet of the internal combustion engine through a pipeline.
Preferably, the refrigerant is an aqueous solution of lithium bromide.
In the embodiment of the invention, the organic Rankine cycle system and the second-class heat pump in the internal combustion engine waste heat utilization system are combined to act, high-temperature exhaust gas generated by the internal combustion engine is processed by the organic Rankine cycle system, and part of energy of the high-temperature exhaust gas is converted into mechanical energy to drive external machinery, so that high-grade energy of the high-temperature exhaust gas is fully utilized. The temperature of the high-temperature exhaust gas is reduced after being processed by the Rankine cycle system to form medium-temperature exhaust gas, and the medium-temperature exhaust gas enters the second-class heat pump, so that the energy of the exhaust gas of the internal combustion engine is fully utilized. In the second type of heat pump, the exhaust water of the internal combustion engine is further heated by the energy of the medium-temperature exhaust gas to form steam with high quality energy, so that the energy of the exhaust gas of the internal combustion engine and the energy of the exhaust water of the internal combustion engine can be further utilized. Therefore, the scheme can fully utilize the high-grade energy of the waste heat of the internal combustion engine and improve the internal combustion engine systemEfficiency is improved.
Drawings
FIG. 1 is a schematic diagram of an internal combustion engine waste heat utilization system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an internal combustion engine waste heat utilization system according to another embodiment of the present invention;
fig. 3 is a schematic diagram of an internal combustion engine waste heat utilization system according to yet another embodiment of the present invention.
Reference numerals:
01-high temperature exhaust;
02-medium temperature exhaust;
03-high-pressure medium-temperature liquid organic working medium;
04-high-pressure high-temperature gaseous organic working medium;
05-low-pressure medium-temperature gaseous organic working medium;
06-low-pressure low-temperature gaseous organic working medium;
07-low pressure low temperature liquid organic working medium;
08-high-pressure low-temperature liquid organic working medium;
09—a dilute solution refrigerant;
010-concentrated solution refrigerant;
011—steam;
012-high pressure liquid water;
013-medium-high-pressure steam;
014-draining;
015-steam;
016-low temperature venting;
100-internal combustion engine;
200-an organic rankine cycle system;
300-a second type heat pump;
400-a first generator;
500-a second generator;
201-a first heat exchanger;
202-turbine;
203-a regenerator;
204-a first condenser;
205-a first booster pump;
301-an evaporator;
302-a generator;
303-a second heat exchanger;
304-a second condenser;
305-a second booster pump;
306-absorber.
Detailed Description
High-grade product for fully utilizing waste heat of internal combustion enginePotential energy for increasing internal combustion engine systemThe embodiment of the invention provides an internal combustion engine waste heat utilization system. The present invention will be further described in detail with reference to the following examples, in order to make the objects, technical solutions and advantages of the present invention more apparent.
As shown in fig. 1, an embodiment of the present invention provides an internal combustion engine waste heat utilization system, including an internal combustion engine 100, an organic rankine cycle system 200, and a second type heat pump 300, wherein: the internal combustion engine 100 includes a drain port and a first exhaust port; the organic rankine cycle system 200 includes a first air inlet, a second air outlet, and a power take-off; the second type heat pump 300 comprises a water inlet and a second air inlet; the first exhaust port of the internal combustion engine 100 is connected with the first air inlet of the organic Rankine cycle system 200 through a pipeline, and the water outlet of the internal combustion engine 100 is connected with the water inlet of the second-class heat pump 300 through a pipeline; the second exhaust port of the organic rankine cycle system 200 is connected to the second inlet port of the second type heat pump 300 through a pipe.
In general, the first type of heat pump is also called a heat-increasing type heat pump, which uses a small amount of high-temperature heat source (such as steam, high-temperature hot water, combustible gas combustion heat and the like) as a driving heat source to generate a large amount of medium-temperature useful heat energy, namely, the heat energy of a low-temperature heat source is increased to medium temperature by utilizing the high-temperature heat energy driving, so that the utilization efficiency of the heat energy is improved. The second type of heat pump is also called a heating type heat pump, and a large amount of medium-temperature heat sources are utilized to generate a small amount of high-temperature useful heat energy, namely, the medium-temperature heat sources are utilized to drive, and the heat potential difference of a large amount of medium-temperature heat sources and low-temperature heat sources is utilized to prepare heat less than but higher than the heat of the medium-temperature heat sources, so that part of the medium-temperature heat energy and the low-temperature heat energy are transferred to higher temperature positions, and the utilization grade of the heat sources is improved.
In this embodiment, the organic rankine cycle system 200 absorbs the thermal energy of the high-temperature exhaust gas 01 of the internal combustion engine 100, converts the thermal energy into mechanical energy, and discharges the medium-temperature exhaust gas 02; the second type of heat pump 300 absorbs the thermal energy of the intermediate-temperature exhaust gas 02 discharged from the organic rankine cycle system 200 to warm the exhaust gas of the internal combustion engine 100 to form steam 015 and discharge the low-temperature exhaust gas 016.
In the embodiment of the invention, the organic Rankine cycle system 200 and the second-class heat pump 300 in the internal combustion engine waste heat utilization system cooperate, the high-temperature exhaust gas 01 generated by the internal combustion engine 100 is processed by the Rankine cycle system, and part of energy of the high-temperature exhaust gas 01 is converted into mechanical energy to drive external machinery, so that high-grade energy of the high-temperature exhaust gas 01 is fully utilized. The temperature of the high-temperature exhaust gas 01 after being processed by the Rankine cycle system is reduced to form medium-temperature exhaust gas 02, and the medium-temperature exhaust gas 02 enters the second-type heat pump 300, so that the heat of the exhaust gas of the internal combustion engine 100 is fully utilized. In the second type of heat pump 300, the heat of the exhaust gas of the internal combustion engine 100 and the heat of the drain 014 of the internal combustion engine 100 can be further utilized by further heating the drain 014 of the internal combustion engine 100 with the heat of the intermediate temperature exhaust gas 02 to form the steam 015 having high-quality energy. Therefore, the scheme can fully utilize the high-grade energy of the waste heat of the internal combustion engine 100 and improve the internal combustion engine systemEfficiency is improved.
It is worth to be noted that, in the embodiment of the present invention, the heat exchanger includes a heating portion and a cooling portion, and the heating portion and the cooling portion both have an outlet and an inlet; the heat regenerator, the evaporator, the generator and the absorber respectively comprise a heat release part and a heat absorption part, and the heat release part and the heat absorption part are respectively provided with an outlet and an inlet.
Referring to fig. 2, in a specific embodiment, an organic rankine cycle system 200 includes a first heat exchanger 201, a turbine 202, a regenerator 203, a first condenser 204, and a first booster pump 205, wherein: the outlet of the heating part of the first heat exchanger 201, the turbine 202, the heat release part of the regenerator 203, the first condenser 204, the first booster pump 205, the heat absorption part of the regenerator 203 and the inlet of the heating part of the first heat exchanger 201 are sequentially connected through an organic working medium pipeline to form an organic circulation loop; the inlet of the cooling part of the first heat exchanger 201 is connected with the first exhaust port of the internal combustion engine 100 through a pipeline, the outlet of the cooling part of the first heat exchanger 201 is connected with the second air inlet of the second type heat pump through a pipeline, and the power output part is the power output shaft of the turbine 202.
In the technical solution of this embodiment, the heat released by the high-temperature exhaust gas 01 of the internal combustion engine 100 through the cooling portion of the first heat exchanger 201 is the high-pressure medium-temperature liquid organic working medium 03 at the heating portion of the first heat exchanger 201, and the high-temperature exhaust gas 01 is cooled to form the medium-temperature exhaust gas 02 and enters the second-type heat pump 300. In the organic circulation system, the high-pressure medium-temperature liquid organic working medium 03 is heated by the heating part of the first heat exchanger 201 and then is converted into a high-pressure high-temperature gaseous organic working medium 04, the high-pressure high-temperature gaseous organic working medium 04 enters the turbine 202, the turbine 202 is driven to rotate and is converted into a low-pressure medium-temperature gaseous organic working medium 05, the low-pressure medium-temperature gaseous organic working medium 05 enters the heat release part of the heat regenerator 203 to release heat and is converted into a low-pressure low-temperature gaseous organic working medium 06, the low-pressure low-temperature gaseous organic working medium 06 is cooled by the first condenser 204 and then is converted into a low-pressure low-temperature liquid organic working medium 07, the low-pressure low-temperature liquid organic working medium 07 is pressurized by the first booster pump 205 and then is converted into a high-pressure low-temperature liquid organic working medium 08, the high-pressure low-temperature liquid organic working medium 08 is converted into the high-pressure medium-temperature liquid organic working medium 03 after the heat release part of the heat regenerator 203 before absorption, and the high-pressure medium-temperature liquid organic working medium 03 enters the heating part of the first heat exchanger 201 for next circulation. The turbine 202 comprises a power output part, and after the high-pressure high-temperature gaseous organic working medium 04 discharged from the temperature rising part of the first heat exchanger 201 enters the turbine 202, the turbine 202 is driven to rotate to convert heat energy into mechanical energy, so that the turbine 202 drives the outside to mechanically move, and the high-grade energy of the high-temperature exhaust gas 01 discharged from the internal combustion engine 100 can be fully utilized.
In a specific embodiment, the internal combustion engine is a power generating internal combustion engine, which is in power connection with the first generator 400. Preferably, the power output unit is in power connection with the second generator 500, and in the power generation system of the internal combustion engine, the exhaust gas of the internal combustion engine can be used for power generation, so that the energy source can be fully utilized, and the power generation efficiency of the power generation system of the internal combustion engine can be improved.
In the organic rankine cycle system 200, the specific type of the organic working medium is not limited, and may be n-pentane, cyclohexane, toluene, dodecane or decane.
Referring to fig. 3, in a specific embodiment, a second type heat pump 300 includes an evaporator 301, a generator 302, a second heat exchanger 303, a second condenser 304, a second booster pump 305, and an absorber 306, wherein: an inlet of the heat release portion of the generator 302 is connected to the second exhaust port of the organic rankine cycle system 200 through a pipe; the first outlet of the heat absorption part of the generator 302, the heating part of the second heat exchanger 303, the heat release part of the absorber 306, the cooling part of the second heat exchanger 303 and the inlet of the heat absorption part of the generator 302 are sequentially connected through a refrigerant pipeline to form a refrigerant circulation loop; an inlet of the heat radiation portion of the evaporator 301 is connected to the second exhaust port of the organic rankine cycle system 200 through a pipe; the second outlet of the heat absorbing portion of the generator 302, the second condenser 304, the second booster pump 305, the heat absorbing portion of the evaporator 301, and the heat releasing portion of the absorber 306 are connected by pipes; the inlet of the heat absorbing portion of the absorber 306 is connected to the water discharge port of the internal combustion engine 100 by a pipe.
In the solution of the present embodiment, a part of the medium-temperature exhaust gas 02 discharged from the organic rankine cycle system 200 enters the heat release portion of the generator 302 of the second-type heat pump 300, and the other part enters the heat release portion of the evaporator 301 of the second-type heat pump 300. The medium-temperature exhaust gas 02 entering the heat release part of the generator 302 releases heat and then is converted into low-temperature exhaust gas 016 to be discharged, the dilute solution refrigerant 09 in the heat absorption part of the generator 302 absorbs the heat released by the medium-temperature exhaust gas 02 and is converted into concentrated solution refrigerant 010 and water vapor 011, wherein the concentrated solution refrigerant 010 discharged from the first outlet of the heat absorption part of the generator 302 is heated by the heating part of the second heat exchanger 303, enters the heat release part of the absorber 306, releases heat and is converted into dilute solution refrigerant 09, the dilute solution refrigerant 09 enters the cooling part of the second heat exchanger 303 to transfer heat to the concentrated solution refrigerant 010 of the heating part, and then enters the heat absorption part of the generator 302 for the next circulation; the water vapor 011 discharged from the second outlet of the heat absorbing part of the generator 302 enters the second condenser 304 to be condensed and then pressurized by the second booster pump 305 to form high-pressure liquid water 012, the high-pressure liquid water 012 enters the heat absorbing part of the evaporator 301 and is heated by the medium-temperature exhaust gas 02 discharged from the organic Rankine cycle system 200 entering the heat releasing part of the evaporator 301 to form medium-temperature high-pressure vapor 013, and the medium-temperature high-pressure vapor 013 enters the heat releasing part of the absorber 306 to be mixed with the concentrated solution refrigerant 010 to form diluted solutionThe liquid refrigerant 09 releases heat, and the water discharge 014 of the internal combustion engine 100 enters the heat absorbing portion of the absorber 306 to absorb the heat and then converts the heat into high-grade energy steam 015. Since the temperature of the drain 014 of the internal combustion engine 100 is high, this embodiment also makes full use of the heat of the drain 014 of the internal combustion engine 100. In this system, the medium-temperature exhaust gas 02 is discharged from the heat release portion of the evaporator 301 and converted into the low-temperature exhaust gas 016. The scheme realizes the full utilization of the waste heat of the medium-temperature exhaust gas 02 and the drain 014, fully utilizes the high-grade energy of the waste heat of the internal combustion engine 100 and improves the internal combustion engine systemEfficiency is improved.
In a preferred embodiment, the refrigerant is an aqueous solution of lithium bromide. The aqueous solution of lithium bromide is colorless liquid, is nontoxic, reduces the solubility of lithium bromide in water with the reduction of temperature, and is very suitable for being used as a refrigerant.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.