Isothermal isobaric marine gas turbine

Abstract

The isothermal and isobaric marine gas turbine comprises an isothermal compression system, an isothermal expansion system, a countercurrent heat exchanger, a liquid fuel tank, a control device, a circulating working medium and connecting pipelines among the isothermal compression system, the isothermal expansion system, the countercurrent heat exchanger, the liquid fuel tank, the control device and the circulating working medium, a working medium inlet of the isothermal compression system is directly connected with the atmosphere, a working medium outlet of the isothermal compression system is communicated with one end of a working medium channel of the countercurrent heat exchanger, and the other end of the working medium channel of the countercurrent heat exchanger is communicated with a working medium inlet of the isothermal expansion system. A tail gas outlet of the isothermal expansion system communicates with a tail gas channel inlet of the countercurrent heat exchanger, and a tail gas channel outlet of the countercurrent heat exchanger communicates with air. According to the design, the efficiency of the gas engine is improved through the multi-stage compression, multi-stage expansion and the isobaric countercurrent flow heat exchange process.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy storage, and particularly relates to an isothermal and isobaric marine gas turbine. Background Art

[0002] As an efficient and clean power equipment, gas turbines are widely used in ship power systems. However, there is still room for improvement in the energy utilization of traditional gas turbines. In order to improve the efficiency of gas turbines and reduce energy consumption and emissions, isothermal multi-stage compression and expansion and countercurrent isobaric heat exchange technologies have been introduced into gas turbine design.

[0003] Isothermal multi-stage compression and expansion technology is an advanced gas turbine technology that uses multiple levels of compression and expansion to keep the working fluid temperature constant during the compression and expansion process, thereby improving energy conversion efficiency. This technology can reduce energy loss during compression and expansion, allowing more energy to be converted into useful mechanical work.

[0004] The countercurrent heat exchanger is one of the key devices to realize the isothermal multi-stage compression and expansion technology. It can effectively recover the heat in the exhaust gas of the gas turbine and use it to preheat the compressed air. This preheating process is carried out under isobaric conditions, which can further improve the efficiency of the gas turbine. Through the design of the countercurrent heat exchanger, the heat in the high-temperature exhaust gas can be fully utilized and energy waste can be reduced.

[0005] In terms of ship applications, since ships sail at sea for a long time, they have a large demand for energy and require the power system to have a high degree of reliability and stability. Therefore, gas turbines that use isothermal multi-stage compression and expansion technology and countercurrent heat exchangers can not only improve energy utilization and reduce energy consumption, but also reduce ship operating costs and improve their economic benefits. Summary of the invention

[0006] The utility model provides an isothermal and isobaric marine gas turbine, which combines three technologies, namely isothermal compression, isothermal expansion and isobaric countercurrent heat exchange, to achieve an organic combination of compressed air power generation and fuel gas, thereby improving the thermal efficiency of the gas turbine.

[0007] The specific description is as follows: An isothermal and isobaric marine gas turbine includes an isothermal compressor, an isothermal expander, a plurality of coolers, a plurality of combustion chambers, a countercurrent heat exchanger, a liquid fuel tank, a control device, a circulating working fluid and connecting pipes therebetween;

[0008] The isothermal compressor is a multi-stage isothermal compressor; the cooler is directly immersed in water for cooling, and the condenser is installed on the compressed working medium pipeline between every two stages of the isothermal compressor;

[0009] The isothermal expander is a multi-stage isothermal expander; the combustion chamber is installed on the expansion medium pipeline between every two stages of isothermal expanders or on the medium pipeline between the countercurrent heat exchanger and the first stage isothermal expander;

[0010] The liquid fuel tank is communicated with each combustion chamber through a pipeline;

[0011] The working fluid inlet of the first-stage isothermal compressor of the isothermal compressor is directly connected to the atmosphere, the working fluid outlet of the last-stage isothermal compressor is connected to the working fluid channel inlet of the countercurrent heat exchanger, and the outlet of the working fluid channel of the countercurrent heat exchanger is connected to the working fluid inlet of the first-stage combustion chamber of the combustion chamber; the exhaust gas outlet of the last-stage isothermal expander of the isothermal expander is connected to the exhaust gas channel inlet of the countercurrent heat exchanger, and the exhaust gas channel outlet of the countercurrent heat exchanger is connected to the air.

[0012] Furthermore, the cooler is directly immersed in water, and the inlet / outlet of the air medium channel of the cooler is respectively connected to the working medium outlet of the previous stage isothermal compressor / the working medium inlet of the next stage isothermal compressor.

[0013] Furthermore, the liquid fuel tank contains one of fuel oil, methanol or liquefied natural gas.

[0014] Furthermore, the isothermal compressor is of centrifugal or axial flow type.

[0015] Furthermore, the isothermal expander is of turbine type.

[0016] Furthermore, the isothermal compressor and the isothermal expander are coaxially connected in series.

[0017] As mentioned above, the gas turbine has a multi-stage isothermal compressor, and the temperature rise of each stage of compression is limited to a small temperature difference. In addition, after each compression, the temperature of the compressed working fluid is lowered by a cooler, which approximately realizes the "isothermal compression" process; a similar method is used to realize the approximate "isothermal expansion" process of the working fluid during the expansion process. This makes the entire thermodynamic process closer to the "Carnot cycle", so a relatively high system thermal efficiency can be obtained.

[0018] By adopting a method of multi-stage expansion accompanied by multi-stage heating, the working fluid can be kept at a higher temperature and a higher average temperature throughout the expansion process compared to a single-stage expansion or a few-stage expansion process. According to the Carnot cycle principle, the higher the temperature, the higher the efficiency of the thermal system. Similarly, through multi-stage compression and heat dissipation cooling, the compression process is kept at a lower temperature to achieve an approximate "isothermal compression", which also improves the efficiency of the thermal system. By comparing the maximum efficiency of the theoretical cycle, the efficiency improvement potential of the utility model can be understood.

[0019] The cooler is directly immersed in seawater, and using seawater for cooling further reduces cooling costs and improves the economy of the system.

[0020] The counter-flow heat exchanger allows the high-temperature exhaust gas and the compressed air to be preheated to flow in the counter-flow direction in the heat exchanger to perform isobaric heat exchange, thereby maximizing the heat exchange efficiency.

[0021] Compared with existing marine gas turbines, this gas turbine uses a multi-stage isothermal compression and expansion working cycle mode, which can optimize temperature management and reduce irreversible losses, and achieve more efficient use of heat; through the design of countercurrent heat exchangers, isobaric recovery and preheating, seawater cooling, and liquid fuel power generation, the energy utilization and efficiency of the shipboard gas turbine system can be significantly improved. These technologies not only help reduce operating costs, but also help reduce environmental pollution and carbon emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Attached Figure 1 It is a schematic diagram of the structure and principle of the gas turbine of the utility model.

[0024] The meanings of the serial numbers in the above figure are as follows: 1 isothermal compressor; 11 first-stage isothermal compressor; 12 secondary isothermal compressor; 1m final-stage isothermal compressor; 2 cooler; 21 first-stage cooler; 22 secondary cooler; 2m-1 final-stage cooler; 3 countercurrent heat exchanger; 4 control device; 5 combustion chamber; 51 first-stage combustion chamber; 52 secondary combustion chamber; 5n final-stage combustion chamber; 6 isothermal expander; 61 first-stage isothermal expander; 62 secondary isothermal expander; 6n final-stage isothermal expander; 7 liquid fuel tank; 81~85 valves. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described in detail below.

[0026] Obviously, the described embodiments are only some embodiments of the present utility model, rather than all the embodiments.

[0027] Based on the embodiments of the present invention, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. To make the embodiments easier to understand, the following provides a variety of embodiments or implementation methods to illustrate the relevant devices, modules, and functions of the present invention.

[0028] In order to enable the readers of this embodiment to quickly understand the implementation mode of the utility model, the following is first described. Figure 1 The working principle expressed is explained.

[0029] As attached Figure 1 As shown, an isothermal and isobaric marine gas turbine comprises: an isothermal compressor 1, a cooler 2, a combustion chamber 5, an isothermal expander 6, a liquid fuel tank 7, a countercurrent heat exchanger 3, a control device 4, a circulating working fluid and connecting pipes therebetween;

[0030] The isothermal compressor 1 is a multi-stage isothermal compressor; the cooler 2 is directly immersed in water for cooling, and the condenser 2 is installed on the compressed working medium pipeline between every two stages of the isothermal compressor;

[0031] The isothermal expander 6 is a multi-stage isothermal expander; the combustion chamber 5 is installed on the expansion medium pipeline between every two stages of isothermal expanders or on the medium pipeline between the countercurrent heat exchanger 3 and the first stage isothermal expander 61;

[0032] The liquid fuel tank 7 is connected to each combustion chamber 5 through a pipeline and a valve;

[0033] The working fluid inlet of the first-stage isothermal expander 11 of the isothermal compressor 1 is directly connected to the atmosphere, the working fluid outlet of the last-stage isothermal compressor 1m is connected to the working fluid channel inlet of the countercurrent heat exchanger 3, and the outlet of the working fluid channel of the countercurrent heat exchanger 3 is connected to the working fluid inlet of the first-stage combustion chamber 51 of the combustion chamber 5; the exhaust gas outlet of the last-stage isothermal expander 6n of the isothermal expander 6 is connected to the exhaust gas channel inlet of the countercurrent heat exchanger 3, and the exhaust gas channel outlet of the countercurrent heat exchanger 3 is connected to the air.

[0034] The function of the isothermal compressor 1 is to inhale working medium air and perform multi-stage isothermal compression on the working medium air to increase the working medium pressure. The isothermal compressor 1 is a multi-stage isothermal compressor, including m-stage compressors 11~1m (m≥2); the working medium inlet of the first-stage isothermal compressor 11 is directly connected to the atmosphere, and the outlet of the last-stage isothermal compressor 1m is connected to the working medium channel inlet of the countercurrent heat exchanger 3.

[0035] The cooler 2 is installed on the compressed working fluid pipeline between every two stages of isothermal compressors, and includes 2 m-1 condensers; the inlet / outlet of the air medium channel of the cooler 2 is respectively connected to the working fluid outlet of the previous stage isothermal compressor / the working fluid inlet of the next stage isothermal compressor; the function of the cooler 2 is to dissipate the heat generated by the isothermal compressor 1 to the outside, so that the compression process is kept at a lower temperature, and an approximate "isothermal compression" is achieved.

[0036] The isothermal expander 6 includes n-stage isothermal expanders (n≥2); the combustion chamber 5 includes a plurality of combustion chambers equal in number to the isothermal expanders 6, and the combustion chamber 5 is installed on the expansion working fluid pipeline between every two stages of isothermal expanders or on the working fluid pipeline between the countercurrent heat exchanger 3 and the first-stage isothermal expander 61, that is, the first-stage combustion chamber 51 is installed on the working fluid pipeline between the working fluid channel of the countercurrent heat exchanger 3 and the first-stage isothermal expander 61, and the inlet / outlet of the combustion chamber 52~5n is respectively connected to the working fluid outlet of the previous stage isothermal expander / the working fluid inlet of the next stage isothermal expander; the working fluid outlet of the last-stage isothermal expander 6n is connected to the exhaust gas inlet of the countercurrent heat exchanger 3.

[0037] The isothermal compressors 11-1m and the isothermal expanders 61-6n are coaxially connected in series.

[0038] The inlet of the working medium channel of the countercurrent heat exchanger 3 is connected to the outlet of the last-stage isothermal compressor 1m; the outlet of the working medium channel of the countercurrent heat exchanger 3 is connected to the working medium inlet of the primary combustion chamber 51; the exhaust gas outlet of the last-stage isothermal expander 6n is connected to the inlet of the exhaust gas channel of the countercurrent heat exchanger 3, and the exhaust gas channel outlet of the countercurrent heat exchanger 3 is directly connected to the air; the function of the countercurrent heat exchanger 3 is to recover the heat of the isothermal expander 6 for preheating the compressed air before doing work; that is, the compressed air coming out of the last-stage isothermal compressor 1m absorbs the heat of the exhaust gas discharged by the last-stage isothermal expander 6n in the countercurrent heat exchanger 3, and then enters the primary combustion chamber 51.

[0039] The combustion chamber 5 is injected with fuel and mixed with the circulating working medium compressed air entering the combustion chamber and then fully burned to produce tail gas. The isothermal expander 6 is connected to the combustion chamber and is driven by the tail gas produced by the combustion chamber 5 to generate power for electricity generation.

[0040] The fuel in the liquid fuel tank 7 is liquid fuel such as fuel oil, methanol or liquefied natural gas.

[0041] If the cooler 2 is a water-cooled cooler, the inlet / outlet of the cooling medium channel of the cooler 2 is respectively connected to the outlet / inlet of the cold water source; if the cooler 2 is an air-cooled cooler, the inlet / outlet of the cooling medium channel of the cooler 2 is connected to the atmosphere.

[0042] The circulating working medium is air.

[0043] The working cycle of the gas turbine of the present invention is as follows: the primary isothermal compressor 11 inhales working medium air from the environment for compression, and the temperature and pressure of the working medium air both rise; in order to prevent the working medium temperature from rising too much, the once pressurized working medium air passing through the primary isothermal compressor 11 directly enters the primary cooler 21 for cooling, and the once pressurized working medium air after cooling enters the secondary isothermal compressor 12 for secondary pressurization, and then enters the secondary cooler 22 for cooling, and so on until it is compressed to a predetermined pressure in the final isothermal compressor 1m, and then directly enters the countercurrent heat exchanger 3 for heat exchange with the high-temperature final tail gas discharged through the final isothermal expander 6n, the compressed air is preheated by the high-temperature final tail gas to become high-pressure medium-temperature compressed air, and then enters the first-stage combustion chamber 51, and at the same time, the liquid fuel in the liquid fuel tank 7 is injected into the first-stage combustion chamber 51 and mixed with the compressed air entering the combustion chamber and fully burned to produce a primary tail gas; the isothermal first-stage expansion The expander 61 is connected to the first-stage combustion chamber 51. The isothermal first-stage expander 61 is driven by the incoming primary exhaust gas and generates power and the primary exhaust gas that is cooled and reduced in pressure after doing work; the cooled and reduced-pressure primary exhaust gas discharged from the isothermal first-stage expander 61 enters the secondary combustion chamber 52, and is mixed with the fuel injected simultaneously with the liquid fuel tank 7 in the secondary combustion chamber 52 and is fully burned again to generate secondary exhaust gas, and then the secondary exhaust gas enters the isothermal secondary expander 62, and the isothermal secondary expander 62 is driven and generates power and the secondary exhaust gas that is cooled and reduced in pressure after doing work; in this way, the exhaust gas is mixed with the fuel injected from the liquid fuel tank 7 to the last combustion chamber 5n for the last combustion to generate the last exhaust gas, and the last exhaust gas drives the last-stage expander 6n to generate power for power generation, and the last exhaust gas discharged from the last-stage expander 6n is not directly discharged into the air, but directly enters the countercurrent heat exchanger 3 for heat recovery, and the temperature of the last exhaust gas discharged from the countercurrent heat exchanger 3 is close to the ambient temperature and is directly discharged into the environment. This repetitive operation completes the entire cycle.

[0044] As mentioned above, the main purpose of using multi-stage compression is to avoid the temperature of the compression process from rising too high, because we want to achieve "approximate" isothermal compression. The entire compression process is completed by the isothermal compressor 1.

[0045] In order to achieve approximate isothermal compression, a cooler 2 is used to dissipate the compression heat of each stage of isothermal compression mechanism into the sea; for this purpose, a cooler 2 is installed between every two stages of isothermal compression mechanism to dissipate the compression heat in time.

[0046] As mentioned above, the main purpose of using multi-stage isothermal expansion is to gradually reduce the pressure of the working medium through multi-stage isothermal expansion, avoid large temperature difference and low efficiency in the expansion process, because we want to achieve "approximate" isothermal expansion. The entire expansion process is completed by the isothermal expander 6. In order to achieve approximate isothermal expansion, the working medium air before entering the isothermal expander 6 is first mixed with the fuel in the combustion chamber 5 and fully burned to produce tail gas of constant temperature, which drives each stage of the isothermal expander to do work.

[0047] The countercurrent heat exchanger 3 is used to allow the high-temperature exhaust gas and the compressed air to be preheated to flow in the heat exchanger in the reverse direction to perform isobaric heat exchange, thereby maximizing the heat exchange efficiency.

[0048] In order to further improve the implementation case of the utility model, a control scheme for the gas turbine of this embodiment is provided here, that is, a set of control devices 4 are provided for the gas turbine, and the preferred control device is a DCS system, which can be used to comprehensively control the various components of the gas turbine in a hierarchical manner and reduce the mutual influence between the various controller devices. The DCS control system collects the working parameters of various components of the engine equipment, including but not limited to temperature, pressure, flow, stress, displacement, vibration, position, current, voltage, resistance, frequency, and power, and comprehensively controls and protects the operation of each component.

[0049] Compared with the existing technology, the utility model adopts a gas turbine with isothermal multi-stage compression and expansion, countercurrent isobaric heat exchange and seawater cooling technology, and uses liquid fuel as energy, providing a highly efficient, environmentally friendly and economical power solution for ships. This not only helps to improve the operational efficiency and economic benefits of ships, but also meets the current social requirements for energy conservation, emission reduction and sustainable development.

Claims

1. An isothermal and isobaric marine gas turbine, characterized in that: It includes an isothermal compressor, an isothermal expander, multiple coolers, multiple combustion chambers, a countercurrent heat exchanger, a liquid fuel tank, a control device, a circulating working fluid and connecting pipes therebetween; The isothermal compressor is a multi-stage isothermal compressor; the cooler is directly immersed in seawater for cooling, and the condenser is installed on the compressed working medium pipeline between every two stages of the isothermal compressor; The isothermal expander is a multi-stage isothermal expander; the combustion chamber is installed on the expansion medium pipeline between every two stages of isothermal expanders or on the medium pipeline between the countercurrent heat exchanger and the first stage isothermal expander; The liquid fuel tank is communicated with each combustion chamber through a pipeline; The working fluid inlet of the first-stage isothermal compressor of the isothermal compressor is directly connected to the atmosphere, the working fluid outlet of the last-stage isothermal compressor is connected to the working fluid channel inlet of the countercurrent heat exchanger, and the outlet of the working fluid channel of the countercurrent heat exchanger is connected to the working fluid inlet of the first-stage combustion chamber of the combustion chamber; the exhaust gas outlet of the last-stage isothermal expander of the isothermal expander is connected to the exhaust gas channel inlet of the countercurrent heat exchanger, and the exhaust gas channel outlet of the countercurrent heat exchanger is connected to the air.

2. The isothermal and isobaric marine gas turbine according to claim 1, characterized in that: The cooler is directly immersed in water, and the inlet / outlet of the air medium channel of the cooler is respectively connected to the working medium outlet of the upper stage isothermal compressor / the working medium inlet of the next stage isothermal compressor.

3. The isothermal and isobaric marine gas turbine according to claim 1, characterized in that: The liquid fuel tank contains one of fuel oil, methanol or liquefied natural gas.

4. The isothermal and isobaric marine gas turbine according to claim 1, characterized in that: The isothermal compressor is of centrifugal or axial flow type.

5. The isothermal and isobaric marine gas turbine according to claim 1, characterized in that: The isothermal expander is of turbine type.

6. The isothermal and isobaric marine gas turbine according to claim 1, characterized in that: The isothermal compressor and the isothermal expander are coaxially connected in series.

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