Combined circulating system of internal combustion engine and micro gas turbine
Technical Field
The invention relates to the technical field of power devices, in particular to a combined cycle system of an internal combustion engine and a micro gas turbine.
Background
Internal combustion engines and micro gas turbines are important power plants and have important applications in the fields of vehicles, ships, engineering machinery, agricultural machinery and power generation. However, with the increasing market reserves of power plants, the emission of greenhouse gases is also increasing year by year, the problem of global warming caused by the emission is a global problem which cannot be ignored, and China also sets the ambitious goals of 2035 carbon peak reaching and 2050 carbon neutralization in China. Under such a background, how to increase the thermal efficiency of internal combustion engines and micro gas turbines becomes an important way to reduce carbon emissions. Combustion and pneumatic optimization of an internal combustion engine and a micro gas turbine are important technical means for improving respective thermal efficiency, and a large amount of basic and engineering research work is developed at present, so that important progress is achieved. However, the technology is mature day by day, and it is difficult to further achieve a great increase in thermal efficiency in this technical route. If the combined cycle of the two power machines can be realized, the heat exchange characteristic is fully utilized according to the characteristics of respective thermodynamic cycles, so that the heat efficiency of the whole power system is improved, and the combined cycle is a technical means for reducing the carbon emission of the power machines.
Disclosure of Invention
The invention aims to overcome the defects and shortcomings of the prior art and provides a combined circulating system of an internal combustion engine and a micro gas turbine, which has the advantages of simple structural design, full utilization of waste gas generated after the turbine of the internal combustion engine and high thermal efficiency of the micro gas turbine.
The technical scheme for realizing the purpose of the invention is as follows: the internal combustion engine and micro gas turbine combined cycle system comprises a turbocharged internal combustion engine system and a micro gas turbine system, wherein the turbocharged internal combustion engine system and the micro gas turbine system are connected through a first heat exchanger and a bypass cooling system.
Further, the turbocharged internal combustion engine system comprises an internal combustion engine, a first turbocharger and a intercooler, wherein the internal combustion engine body, the first turbocharger and the intercooler are connected through pipelines to form a closed loop.
Further, the micro gas turbine system comprises a combustion chamber, a second heat exchanger and a second turbocharger, wherein the second heat exchanger is connected with the combustion chamber and the second turbocharger through pipelines to form a closed loop.
Further, the first heat exchanger is arranged on a pipeline between the second heat exchanger and the second turbocharger, and the first heat exchanger is connected with the first turbocharger through a pipeline.
Further, bypass cooling system establishes between intercooler and second turbo charger, bypass cooling system includes the bypass pipeline and establishes the automatically controlled valve on the bypass pipeline, the both ends of bypass pipeline are connected with first turbo charger and second turbo charger respectively.
After the technical scheme is adopted, the invention has the following positive effects:
(1) according to the invention, the first heat exchanger is arranged on the pipeline between the second heat exchanger and the second air compressor, and is connected with the first turbine through the pipeline, so that the internal energy of the gas after the internal combustion engine is whirled is transmitted to the air inlet of the micro gas turbine, the energy of the waste gas after the internal combustion engine is whirled is utilized, the air inlet temperature of the combustion chamber of the micro gas turbine is increased, and the purpose of improving the heat efficiency of the micro gas turbine can be achieved according to the Brayton thermodynamic cycle basic principle of the micro gas turbine;
(2) according to the invention, the bypass cooling system is arranged between the intercooler and the second turbine, so that part of fresh air cooled by the internal combustion engine through the intercooler is extracted and introduced to the end of the second turbine of the micro gas turbine to cool the blades of the second turbine, and the reliability of the turbine blades of the micro gas turbine is improved, thus the inlet temperature of the turbine of the micro gas turbine is allowed to be improved, and the heat efficiency of the micro gas turbine can be further improved according to the Brayton thermodynamic cycle basic principle of the micro gas turbine.
Drawings
In order that the present disclosure may be more readily and clearly understood, the following detailed description of the present disclosure is provided in connection with specific embodiments thereof and with the accompanying drawings, in which:
FIG. 1 is a schematic structural diagram of the present invention.
In the figure: the internal combustion engine comprises a turbocharged internal combustion engine system 1, an internal combustion engine 11, a first turbocharger 12, a first compressor 121, a first turbine 122, an intercooler 13, a crankshaft 14, an outlet pipeline 15, a first air inlet pipeline 16, a micro gas turbine system 2, a combustion chamber 21, a second heat exchanger 22, a second turbocharger 23, a rotating shaft 24, a second air inlet pipeline 25, a second compressor 231, a second turbine 232, a cooling mechanism 2321, a first heat exchanger 3, a bypass cooling system 4, a bypass pipeline 41 and an electric control valve 42.
Detailed Description
As shown in fig. 1, an internal combustion engine and micro gas turbine combined cycle system includes a turbocharged internal combustion engine system 1 and a micro gas turbine system 2, where the turbocharged internal combustion engine system 1 includes an internal combustion engine 11, a first turbocharger 12 and a intercooler 13, the first turbocharger 12 is composed of a first compressor 121 and a first turbine 122, and the internal combustion engine 11, the first turbocharger 12 and the intercooler 13 are connected by pipes to form a closed loop; the micro gas turbine system 2 comprises a combustion chamber 21, a second heat exchanger 22 and a second turbocharger 23, wherein the second turbocharger 23 consists of a second compressor 231 and a second turbine 232, and the second heat exchanger 23 is respectively connected with the combustion chamber 21 and the second turbocharger 22 through pipelines to form a closed loop; a first heat exchanger 3 is arranged on a pipeline between the second heat exchanger 22 and a second compressor 231 of the second turbocharger 23, and the first heat exchanger 3 is connected with a first turbine 122 of the first turbocharger 12 through a pipeline; the first heat exchanger 3 is arranged on a pipeline between the second heat exchanger 22 and the second compressor 231, and the first heat exchanger 3 is connected with the first turbine 122 through a pipeline, so that the energy of the exhaust gas after the vortex of the internal combustion engine 11 is transmitted to the air inlet of the micro gas turbine, and the thermal efficiency of the micro gas turbine is improved while the energy of the exhaust gas after the vortex of the internal combustion engine 11 is utilized. A bypass cooling system 4 is further arranged between the intercooler 13 and the second turbine 232 of the second turbocharger 23, the bypass cooling system 4 comprises a bypass pipeline 41 and an electric control valve 42 arranged on a pipeline of the bypass pipeline 41, and two ends of the bypass pipeline 41 are respectively connected with the cooling mechanisms 2321 on the intercooler 13 and the second turbine 232; a bypass cooling system 4 is arranged between the intercooler 13 and the second turbine 232, so that a part of fresh air cooled by the intercooler 13 of the internal combustion engine 11 is extracted and introduced to the second turbine 232 end of the micro gas turbine for cooling the blades of the second turbine 232, and the thermal efficiency of the micro gas turbine is improved; the setting of the electronic control valve 42 can adjust the working state of the bypass cooling system 4 according to the requirement of the operation condition of the combined cycle system: when the combined cycle system is in low working condition operation, the combustion temperature of the micro gas turbine is relatively low, the second turbine 232 can meet the requirement of reliability, the electric control valve 42 is closed, and the bypass cooling system 4 does not work; when the combined cycle system is in high-power operation, the discharge temperature of the micro gas turbine is high, and at this time, in order to reduce the heat load of the second turbine 232, the electronic control valve 42 may be opened, so that a part of the cooled fresh air in the pipe behind the intercooler 13 enters the bypass pipe 41, and then the second turbine 232 is cooled by the cooling structure 2321 on the second turbine 232, thereby improving the reliability of the micro gas turbine.
The turbocharged internal combustion engine system 1 injects oil and burns through the internal combustion engine 11, the burnt engine outputs power outwards through the crankshaft 14, exhaust gas enters the first turbine 122 through a pipeline to expand and work, internal energy of the exhaust gas which works through the first turbine 122 is converted into mechanical energy to drive the first compressor 121 to rotate and work, on the other hand, the exhaust gas energy which is not completely utilized is transmitted to fresh air behind the second compressor 232, and the exhaust temperature behind the first turbine 122 can reach 550-650 ℃ during high-working-condition operation of a general engine. After the first compressor 121 obtains the mechanical energy transmitted by the first turbine 122, the first compressor rotates and compresses air to do work, fresh air is sucked into the first compressor 121 through a pipeline, and the mechanical energy of the first compressor 121 is converted into pressure energy and internal energy in the first compressor 121. The air in the rear outlet duct 15 of the first compressor 121 has a higher pressure and temperature, since it is compressed by the first compressor 121. In order to increase the intake air amount per unit time of the internal combustion engine 11 and thus increase the power density and efficiency, the thermodynamic system of the internal combustion engine following the sabaded basic thermodynamic cycle needs to reduce the temperature of the air in the first intake duct 16 as much as possible, so that an intercooler 13 is added to the rear duct of the first compressor 121 for cooling the intake air of the engine. Meanwhile, the fuel is combusted in the combustion chamber 21, and the combusted high-temperature and high-pressure fuel gas enters the second heat exchanger 22 through a pipeline and then enters the second turbine 232 through the pipeline to perform work through expansion. The high-temperature high-pressure gas converts pressure energy and internal energy into mechanical energy in the second turbine 232, the mechanical energy is used for driving the second compressor 231 to compress air to do work on one hand, and the residual power is output outwards through the rotating shaft 24 of the second turbine 232 on the other hand. Fresh air is sucked into the second air compressor 231 through a pipeline, mechanical energy is converted into pressure energy and internal energy of the fresh air, the compressed fresh air enters the first heat exchanger 3 through the pipeline to be mixed with exhaust gas which is not completely utilized after the vortex of the internal combustion engine 11, and the mixed gas is heated through two stages of the first heat exchanger 3 and the second heat exchanger 22, so that the temperature in the second air inlet pipeline 25 is increased to be higher, the heat efficiency increasing direction of the Brayton cycle is met, and the heat efficiency of the micro gas turbine is increased. Although the thermal efficiency of the internal combustion engine 11 in the combined cycle system is not improved, the thermal efficiency of the micro gas turbine is improved by exchanging heat with the micro gas turbine by using the operating mode of the internal combustion engine 11, so that the thermal efficiency of the combined cycle system is improved.
The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.