Humidifying gas turbine system based on dew point evaporative cooling

Abstract

The invention discloses a humidifying gas turbine system based on dew-point evaporative cooling, which comprises a dew-point evaporative cooler, an intermediate saturator, a measurement and control system and a gas turbine assembly, the intermediate saturator (composed of a dew point evaporative cooler and an indirect evaporative cooler) is used for waste heat recovery and gas supply humidification, and the measurement and control system is used for adjusting the flow ratio of the dew point evaporative cooler, monitoring biomass gas components supplied into the combustion chamber and adjusting the water supply amount of the intermediate saturator. The gas turbine assembly is used to complete a gas turbine thermodynamic cycle. The dew-point evaporative cooling device provided by the invention can be optimized and adjusted according to different environmental working condition requirements, the inlet temperature of the gas turbine and the amount of water vapor in the combustion chamber are controlled, the sensitivity limitation of a traditional gas turbine on the change of components in biomass gas is broken through, and the adaptability and environmental protection property of a gas turbine system are improved.

Description

Technical Field

[0001] The invention relates to the field of gas turbines, and in particular to a humidified gas turbine system based on dew point evaporative cooling. Background Art

[0002] At present, distributed energy technologies in buildings can be divided into two categories. One is renewable energy technologies including photovoltaics, wind power, biomass energy, etc. ("open source type"), and the other is multi-generation technology with internal combustion engines, gas turbines, Stirling engines, fuel cells, etc. as prime movers ("throttling type"). The distributed energy system driven by biomass gas micro gas turbine has the advantages of using renewable energy and multi-generation technology to utilize primary energy in a cascade manner, and has broad application prospects. However, due to the introduction of biomass gas, the power generation efficiency of the gas turbine is reduced, and the wide source of biomass gas and large changes in components lead to fluctuations in gas turbine performance. At the same time, considering the dynamic changes in building loads, there will be dual uncertainties of dynamic changes in supply-side output and random fluctuations in demand-side loads, which makes the optimization of building distributed energy systems driven by biomass gas micro gas turbines challenging.

[0003] Gas turbines play a vital role in energy supply systems, with capacity flexibility and low maintenance costs. It is generally used in three types of applications. The first is that gas turbines are used directly for power generation, the second is a combined cycle system in which gas turbines are used as part of the system, and the third is a polygeneration system that simultaneously generates cooling, heating, and electricity. According to statistics from the U.S. Department of Energy, gas turbine technology plays a key role in more than 70% of polygeneration systems. Efficient energy conversion devices combined with renewable energy can effectively alleviate environmental problems caused by primary energy consumption and pollutant emissions. With the development of this research direction, various research institutions and enterprises in the world have focused on gas turbine technology for replacing natural gas with biomass gas. Biomass gas micro gas turbines have gradually become an important technology. A large number of experimental tests and numerical simulation studies have analyzed biomass gas micro gas turbines and their components, verifying the feasibility of biomass gas micro gas turbines. However, the study also pointed out that due to the power loss of fuel compression, the net efficiency of the gas turbine decreases as the methane content in the biomass gas decreases, and as the carbon dioxide content increases, the generation of NOx and CO in the combustion chamber will also increase. In order to improve the performance of biomass gas micro gas turbines and improve the performance degradation problem caused by the introduction of biomass gas, scholars have optimized the biomass gas micro gas turbine, such as optimizing the nozzle and combustion chamber, increasing the temperature and pressure of the turbine compressor components, etc. The performance of biomass gas micro gas turbines can be effectively improved by component optimization. However, the component optimization of micro gas turbines has reached a certain bottleneck, and the cost of further optimization is unbearable or difficult to achieve in terms of current material technology. The present invention intends to adopt a new thermodynamic cycle process, using a high-efficiency dew point evaporative cooling heat exchanger to recover waste heat and generate steam to increase the turbine working fluid flow rate. The humidified gas turbine cycle is a new idea to alleviate the decline in gas turbine efficiency caused by the introduction of biomass gas. Summary of the invention

[0004] In order to improve the performance of a gas turbine system, the present invention provides a humidified gas turbine system based on dew point evaporative cooling, which can improve the performance of the gas turbine affected by biomass gas.

[0005] In order to achieve the above object, the technical solution provided by the present invention is:

[0006] A humidified gas turbine system based on dew point evaporative cooling comprises: a dew point evaporative cooler, an intermediate saturator, a measurement and control system and a gas turbine assembly, wherein the dew point evaporative cooler is used to cool the gas turbine supply air temperature, the intermediate saturator is used for waste heat recovery and air supply humidification, the measurement and control system is used to adjust the flow ratio of the dew point evaporative cooler, monitor the biomass gas components entering the combustion chamber and adjust the water amount entering the intermediate saturator, and the gas turbine assembly is used to complete the thermal cycle power generation process.

[0007] Furthermore: the dew point evaporative cooler cools the inlet air based on the dew point evaporative cooling principle, and includes a dry channel and a wet channel. The wet channel uses the return air from the dry channel as the reference inlet operating condition for humidification cooling, thereby cooling the air in the dry channel, and then cooling the gas turbine supply air temperature to improve system efficiency; the dry channel mainly reduces the supply air temperature, while the wet channel uses direct evaporative cooling to achieve the cooling process, but its reference operating condition is the air temperature after the dry channel is cooled, so the dry channel supply air temperature can be lower than its inlet wet bulb temperature and close to its dew point temperature.

[0008] The intermediate saturator realizes waste heat recovery and air supply humidification by coupling a dew point evaporative cooler and an indirect evaporative cooler;

[0009] The measurement and control system includes biomass gas fuel composition monitoring, gas flow rate and water flow rate control valves, monitors different biomass gas fuel components, and adjusts gas and water supply parameters to achieve efficient operation of the system;

[0010] The gas turbine assembly comprises a compressor, a turbine and a generator to complete the gas turbine thermal cycle power generation process.

[0011] Furthermore, the dew point evaporative cooler further comprises a No. 1 fan and a No. 2 fan; the No. 1 fan is an air inlet, and the No. 2 fan is an air outlet; a nozzle is provided on the inner wall of the wet channel, the nozzle is connected to the No. 1 water pump, and the nozzle sprays water to the inner wall of the wet channel to form a water film. The flow ratio of the dry channel and the wet channel of the dew point evaporative cooler can be adjusted by the speed of the two fans to match and achieve the best cooling efficiency under different working conditions.

[0012] The dew point evaporative cooler of the present invention has no high energy consumption power components, and optimizes and adjusts the dew point evaporation efficiency only by adjusting the flow ratio by a fan and spraying water for evaporation.

[0013] The gas turbine assembly includes a compressor, a combustion chamber, a fuel pump, a turbine and a generator; the compressor air inlet and outlet are respectively connected to the dry channel of the dew point evaporative cooler and the intermediate saturator, and the air enters the compressor in the gas turbine assembly after being cooled by the evaporative cooler, and the air enters the intermediate saturator after being compressed; the wet hot compressed air outlet of the intermediate saturator is connected to the combustion chamber, and the wet hot compressed air is discharged into the combustion chamber, and the combustion exhaust gas is discharged into the turbine after being fully mixed with the fuel introduced by the fuel pump and burned. The exhaust gas of the turbine enters the intermediate saturator again for waste heat recovery, and the generator in the gas turbine assembly uses the shaft work provided by the turbine to complete power generation.

[0014] Due to the humidification effect, the gas turbine assembly can achieve stable operation when the main component of CH4 in the biomass gas fluctuates between 45% and 75%, and the output efficiency fluctuation does not exceed 10%, reducing the sensitivity of the gas turbine system to the biomass gas component.

[0015] Further, the intermediate saturator includes three pipelines: turbine exhaust gas, compressor air and cooling water;

[0016] The exhaust gas of the turbine enters from the upper inlet of the intermediate saturator for waste heat recovery. The waste heat of the exhaust gas is recovered by heating the compressed air and cooling water, and the compressed air is heated and humidified to recover heat energy. The measurement and control system measures and controls the gas supply components of the biomass gas to adjust the gas supply and water supply to achieve efficient operation of the system.

[0017] The air from the compressor enters from the lower inlet of the intermediate saturator. Part of the compressed air is cooled and flows into the upper end of the intermediate saturator. Part of the compressed air takes away part of the cooling water and becomes wet compressed air. The two parts of compressed air merge at the upper end and then discharge the wet and hot compressed air into the combustion chamber to be fully mixed with the fuel for combustion.

[0018] The cooling water enters from the upper inlet of the intermediate saturator to cool the turbine exhaust gas and the compressor air respectively. Part of the cooling water is used to humidify the compressed air and then flows out from the lower outlet of the intermediate saturator. Part of the cooling water enters the cooling water tower for cooling cycle regeneration, and part of the cooling water enters the compressor to achieve compressor temperature control. This can not only efficiently recover waste heat, but also increase the turbine mass flow rate, thereby effectively improving system efficiency.

[0019] The intermediate saturator realizes waste heat recovery and air supply humidification by coupling the dew point evaporative cooler and the indirect evaporative cooler. Due to the air supply humidification, heat-work conversion can be realized at a lower temperature, thereby improving the adaptability of the system.

[0020] The beneficial effects of the present invention relative to the prior art are:

[0021] The dew point evaporative cooler in the humidified gas turbine system provided by the present invention can adjust the wet channel flow ratio and the air temperature in the dry channel by spraying water to cool the dry channel according to the reference working condition of the air introduced at the dry channel inlet, and can be coupled with the indirect evaporative cooler to realize waste heat recovery and air supply humidification, thereby ensuring that the system efficiency is effectively improved; in addition, by monitoring the biomass gas fuel components at the fuel inlet, and regulating the air supply valve and the water supply valve, the influence of the biomass gas on the gas turbine components is reduced, thereby improving the system adaptability. The dew point evaporative cooling gas turbine system of the present invention can reasonably adjust the inlet flow ratio, effectively recover waste heat to improve the efficiency of the gas turbine, and can conveniently cope with the fluctuations of different biomass fuel components, thereby improving the adaptability of the gas turbine system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the principle of a dew point evaporative cooling humidified gas turbine system provided by the present invention;

[0023] Figure 2 The working principle diagram of dew point evaporative cooling provided by the present invention;

[0024] Figure 3 Based Figure 2 Temperature-enthalpy diagram corresponding to the inlet and outlet air temperatures of the dew point evaporative cooler;

[0025] Figure 4 Schematic diagram of the intermediate saturator provided by the present invention;

[0026] Figure 5 A schematic diagram of the control principle flow chart provided by the present invention;

[0027] In the figure, 1-dew point evaporative cooler, 11-fan No. 1, 12-fan No. 2, 13-wet channel, 14-dry channel, 15-nozzle, 16-water pump No. 1, 2-intermediate saturator, 3-measurement and control system, 4-turbine gas turbine assembly, 5-compressor, 6-combustion chamber, 7-fuel pump, 8-turbine, 9-generator, 10-water pump No. 2. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0030] Reference Figure 1This embodiment provides a humidified gas turbine system based on dew point evaporative cooling, comprising: a dew point evaporative cooler 1, an intermediate saturator 2, a measurement and control system 3 and a gas turbine assembly 4, wherein the dew point evaporative cooler 1 is used to cool the gas turbine supply air temperature, the intermediate saturator 2 is used for waste heat recovery and air supply humidification, the measurement and control system 3 is used to adjust the flow ratio of the dew point evaporative cooler 1 and monitor the biomass gas components entering the combustion chamber, and the gas turbine assembly 4 is used for the gas turbine thermal cycle.

[0031] The dew point evaporative cooler 1 and the intermediate saturator 2 will be specifically introduced below.

[0032] Reference Figure 2 The dew point evaporative cooler 1 comprises a No. 1 fan 11, a dry channel 14, a wet channel 13 and a No. 2 fan 12 in sequence; the No. 1 fan 11 is an air inlet, and the No. 2 fan 12 is an air outlet; a nozzle 15 is provided on the inner wall of the wet channel 13, and the nozzle 15 is connected to a No. 1 water pump 16, and the nozzle 15 sprays water onto the inner wall of the wet channel 13 to form a water film;.

[0033] Figure 2 This is the working principle diagram of the dew point evaporative cooler 1. Figure 3 The temperature-enthalpy diagram corresponding to the inlet and outlet air temperatures of dew point evaporative cooler 1.

[0034] The dew point evaporative cooler 1 adjusts the flow ratio of the dry channel 14 and the wet channel 13 by adjusting the rotation speed of the first fan 11 and the second fan 12, and performs cooling in conjunction with water spray evaporation to achieve that the air supply temperature of the dry channel 14 is lower than its inlet wet bulb temperature.

[0035] The dew point evaporative cooler 1 has no high energy consumption power components such as a compressor, and the dew point evaporation efficiency can be adjusted from 0.6 to 0.95.

[0036] The gas turbine assembly 4 includes a compressor 5, a combustion chamber 6, a fuel pump 7, a turbine 8 and a generator 9; the compressor 5 is connected to the dry channel 14 of the dew point evaporative cooler 1;

[0037] Reference Figure 4The intermediate saturator 2 includes three pipelines: the exhaust gas from the turbine 8, the air from the compressor 5, and the cooling water. The exhaust gas from the turbine 8 enters from the upper inlet of the intermediate saturator 2, is cooled by the cooling water and the compressed air, and is discharged from the rear end of the intermediate saturator 2; the air from the compressor 5 enters from the lower inlet of the intermediate saturator 2, 1 / 3 of the compressed air flows into the upper end of the intermediate saturator 2 after cooling, and 2 / 3 of the compressed air takes away a small amount of cooling water to become wet compressed air. After the two parts of compressed air merge at the upper end, the wet and hot compressed air is discharged into the combustion chamber 6 to be fully mixed with the fuel for combustion; the cooling water enters from the upper inlet of the intermediate saturator 2 to cool the exhaust gas from the turbine 8 and the air from the compressor 5 respectively. Part of the cooling water is used to humidify the compressed air, and then flows out from the lower outlet of the intermediate saturator 2, part of it enters the cooling water tower for recycling, and part of it enters the compressor 5 to realize the recycling of cooling water.

[0038] The intermediate saturator 2 is supplemented with circulating water via the No. 2 water pump 10;

[0039] The intermediate saturator 2 realizes waste heat recovery and air supply humidification by coupling a dew point evaporative cooler and an indirect evaporative cooler, which can not only efficiently recover waste heat but also increase the mass flow of the turbine 8, thereby effectively improving system efficiency.

[0040] The intermediate saturator 2 achieves the purpose of air supply humidification by coupling the dew point evaporative cooler and the indirect evaporative cooler, and increases the mass flow of the turbine 8 without changing the power consumption of the compressor, thereby increasing the system output power.

[0041] Reference Figure 5 The control principle flow of the control system 3 includes the control of the fan speed, the compression ratio of the compressor 5 and the water pump power. The measurement and control system 3 measures the outlet air temperature of the dry channel 14 and the wet channel 13 of the dew point evaporative cooler 1 and the water supply flow of the wet channel 13, measures the air supply flow of the compressed air discharged by the compressor 5 and the water supply flow of the cooling water of the intermediate saturator 2, measures and controls the fuel component of the biomass gas supplied to the combustion chamber 6, and changes the above parameters by adjusting the fan speed, the compression ratio of the compressor 5 and the power of the No. 1 water pump 16 and the No. 2 water pump 10 in an electric current manner to achieve efficient operation of the system.

[0042] The gas turbine assembly 4 is a humidified gas turbine system. Due to the humidification effect, it can achieve stable operation when the main component of CH4 in the biomass gas fluctuates between 45% and 75%. The output efficiency fluctuation does not exceed 10%, reducing the sensitivity of the gas turbine system to the biomass gas components.

[0043] Reference Figure 1A humidified gas turbine system based on dew point evaporative cooling is provided. After air enters a dew point evaporative cooler 1, it is cooled and then enters a compressor 5 in a gas turbine assembly 4. After being compressed, the air enters an intermediate saturator 2, and then the moist hot compressed air is discharged into a combustion chamber 6 in the gas turbine assembly 4. At the same time, the air is fully mixed with the fuel introduced by a fuel pump 7 and burned, and then the combustion exhaust gas is discharged into a turbine 8. The exhaust gas of the turbine 8 repeatedly enters the intermediate saturator 2 for circulation. The generator 9 in the gas turbine assembly 4 generates electricity by outputting shaft work of the turbine 8. The measurement and control system 3 measures the outlet air temperature of a dry channel 14 and a wet channel 13 of the dew point evaporative cooler 1 and the water supply flow rate of the wet channel 13, measures the air supply flow rate of the compressed air discharged by the compressor 5 and the water supply flow rate of the cooling water of the intermediate saturator 2, and monitors the fuel component of the biomass gas entering the combustion chamber 6, so as to adjust the fan speed, the compression ratio of the compressor 5 and the power of the first water pump 16 and the second water pump 10 to change the above parameters, thereby realizing efficient operation of the system and effectively improving the system efficiency.

[0044] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A humidified gas turbine system based on dew point evaporative cooling, It is characterized in that include: A dew point evaporative cooler (1), an intermediate saturator (2), a measurement and control system (3) and a gas turbine assembly (4), wherein the dew point evaporative cooler (1) is used to cool the gas turbine supply air temperature, the intermediate saturator (2) is used for waste heat recovery and supply air humidification, the measurement and control system (3) is used to adjust the flow ratio of the dew point evaporative cooler (1) and monitor the biomass gas components entering the combustion chamber of the gas turbine assembly (4), and the gas turbine assembly (4) is used for the gas turbine thermal cycle.

2. A humidified gas turbine system based on dew point evaporative cooling according to claim 1, Features: The dew point evaporative cooler (1) cools inlet air based on the dew point evaporative cooling principle, and comprises a dry channel (14) and a wet channel (13). The wet channel (13) uses the return air of the dry channel (14) as a reference inlet operating condition for humidification cooling, thereby cooling the air in the dry channel (14), and further cooling the gas turbine supply air temperature. The intermediate saturator (2) realizes waste heat recovery and air supply humidification by coupling a dew point evaporative cooler and an indirect evaporative cooler; The measurement and control system (3) includes biomass gas fuel composition monitoring, gas flow and water flow control valves, monitors different biomass gas fuel components, and adjusts gas supply and water supply parameters; The gas turbine assembly (4) comprises a compressor (5), a combustion chamber (6) and a turbine (8) to complete the gas turbine thermal cycle process.

3. A humidified gas turbine system based on dew point evaporative cooling according to claim 2, Features: The dew point evaporative cooler (1) further comprises a first fan (11) and a second fan (12); the first fan (11) is an air inlet, and the second fan (12) is an air outlet; a nozzle (15) is provided on the inner wall of the wet channel (13), the nozzle (15) is connected to a first water pump (16), and the nozzle (15) sprays water onto the inner wall of the wet channel (13) to form a water film.

4. A humidified gas turbine system based on dew point evaporative cooling according to claim 2, Features: The gas turbine assembly (4) comprises a compressor (5), a combustion chamber (6), a fuel pump (7), a turbine (8) and a generator (9); the air inlet and the air outlet of the compressor (5) are respectively connected to the dry channel (14) of the dew point evaporative cooler (1) and the intermediate saturator (2); the air supply passes through the dew point evaporative cooler (1) and is cooled before entering the compressor (5) in the gas turbine assembly (4); the air enters the intermediate saturator (2) after being compressed; the wet hot compressed air outlet of the intermediate saturator (2) is connected to the combustion chamber (6), and the wet hot compressed air is discharged into the combustion chamber (6), and at the same time, the wet hot compressed air is fully mixed with the fuel introduced by the fuel pump (7) and burned, and then the combustion exhaust gas is discharged into the turbine (8); the exhaust gas of the turbine (8) enters the intermediate saturator (2) again to recover the waste heat, and the generator (9) in the gas turbine assembly (4) outputs electricity using the shaft work of the turbine (8).

5. A humidified gas turbine system based on dew point evaporative cooling according to any one of claims 1 to 4, Features: The intermediate saturator (2) includes three pipelines: turbine exhaust gas, compressor air and cooling water; The exhaust gas of the turbine (8) enters from the inlet at the upper end of the intermediate saturator (2), is cooled through the cooling water circuit, and is discharged from the rear end of the intermediate saturator (2); The air from the compressor (5) enters from the lower inlet of the intermediate saturator (2), part of the compressed air is cooled and flows into the upper end of the intermediate saturator (2), part of the compressed air takes away part of the cooling water and becomes wet compressed air, and the two parts of compressed air are combined at the upper end and discharged to enter the combustion chamber (6) to be fully mixed with the fuel for combustion; Cooling water enters from the upper inlet of the intermediate saturator (2) to cool the exhaust gas of the turbine (8) and the air of the compressor (5), respectively. Part of the cooling water is used to humidify the compressed air and then flows out from the lower outlet of the intermediate saturator (2) to cool the compressor (5) to achieve recycling of cooling water. The intermediate saturator (2) realizes waste heat recovery and air supply humidification by coupling a dew point evaporative cooler and an indirect evaporative cooler.

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