Mixed combustion power generation system utilizing high-concentration gas and low-concentration gas
Technical Field
The invention relates to the field of machinery, in particular to a power generation system by mixed combustion of high-concentration gas and low-concentration gas.
Background
At present, a gas combustion power generation system is mainly used for driving a generator to generate power by an internal combustion engine, a gas turbine, a Stirling engine, a steam turbine and the like, and in order to realize stable operation of a driving machine, the concentration of gas is generally required to be at least more than 9% V so as to meet the requirement of stable air-fuel ratio, realize stable combustion of the gas and drive the generator to generate power. For gas with the concentration lower than 9% V, such as coal bed gas, the environment pollution and resource waste caused by directly discharging the atmosphere are generally caused at present, and the gas needs to be recycled. For low-concentration gas, various restriction factors exist in the current utilization process, especially for gas which is mixed with air and is within an explosion limit range and has 5-9% V, safety must be ensured in the combustion power generation process, and in addition, because the low-concentration gas has a low heat value and cannot be directly combusted and utilized, high-concentration gas needs to be mixed in the utilization process so as to meet the air-fuel ratio requirements of normal combustion and power generation. The low-concentration gas is effectively utilized to burn and generate electricity, two key problems of safe mixing and stable burning need to be solved at the same time, and especially, the safety problem is easy to occur in the system starting and stopping process and the back application end backfire accident state, thereby influencing the safe utilization of the low-concentration gas.
Disclosure of Invention
In order to overcome the defects, the invention provides a power generation system by mixed combustion of high-concentration gas and low-concentration gas.
A power generation system utilizing mixed combustion of high-concentration gas and low-concentration gas comprises a low-concentration gas conveying pipeline and a high-concentration gas pipeline; the gas generator system is connected in the gas inlet system, the gas inlet system comprises a low-concentration gas conveying pipeline and a high-concentration gas pipeline, a gas inlet, a water ring vacuum pump, a flame arrester, a pressure detection sensor, a valve, a flowmeter, a concentration detector, a mixer, an emptying valve, a switching valve and a gas generator system are sequentially arranged on the low-concentration gas conveying pipeline, the gas generator system is arranged at the tail end of the mixer, a control valve is connected with a gas inlet, an air purging inlet is connected with the low-concentration gas conveying pipeline, the air purging inlet is connected with the low-concentration gas conveying pipeline at the right side of the gas inlet, a control valve II is arranged on the air purging inlet, a quick safety shut-off valve, a pressure sensor, a regulating valve and a flowmeter I are sequentially arranged on the high-concentration gas pipeline, the tail end of the high-concentration gas pipeline is connected with the mixer, and a smoke exhaust flue is arranged on the gas generator system, the upper part of the smoke exhaust flue is provided with a steam generator, and a coil pipe is arranged in the steam generator.
The mixer is provided with a mixing member and a safety fire retardant member.
The end of the mixer in the air inlet system is connected with a heating furnace. The tail end of a mixer in the air inlet system is respectively connected with the heating furnace and the gas generator system.
The mixing and allocating control system is respectively in wired connection with the quick safety shut-off valve, the pressure sensor, the regulating valve, the flowmeter, the first control valve, the second control valve, the second flowmeter, the concentration detector, the emptying valve and the switching valve.
Has the advantages that: the high-concentration and low-concentration gas mixed combustion power generation system solves the problem of matching and adjusting the gas concentration in the low-concentration gas combustion power generation process, realizes the mixed safe combustion power generation of low-concentration gas and high-concentration gas and the recovery of the waste heat of the flue gas, can be widely applied to various low-concentration gas combustion power generation systems, and realizes the efficient safe combustion power generation and the waste heat recovery and utilization of the low-concentration gas.
Drawings
Fig. 1 and 2 are schematic structural views of a first embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a second embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a third embodiment of the present invention.
In the figure: 1. the system comprises a low-concentration gas conveying pipeline, 2, a first control valve, 3, an air purging inlet, 4, a second control valve, 5, a high-concentration gas pipeline, 6, a quick safety cut-off valve, 7, a pressure sensor, 8, a regulating valve, 9, a first flowmeter, 10, a mixing and allocating control system, 11, a coil pipe, 12, a steam generator, 13, a smoke exhaust flue, 15, an emptying valve, 16, a gas generator system, 17, a switching valve, 18, a safe fire retardant component, 19, a mixing component, 20, a mixer, 21, a concentration detector, 22, a second flowmeter, 23, a valve, 24, a pressure detection sensor, 25, a fire retardant, 26, a water ring vacuum pump, 27, an air inlet, 28, an air inlet system, 29 and a heating furnace.
Detailed Description
As shown in fig. 1-4: when the gas generator works normally, low-concentration gas is introduced into the gas generator system 16 from the low-concentration gas conveying pipeline 1 through the water ring vacuum pump 26; the low-concentration gas passes through a flame arrester 25, the pressure sensor 24 detects the pressure of the low-concentration gas, the pressure sensor 24 determines that the low-concentration gas meets the requirement of normal working pressure, then the flow of the low-concentration gas is controlled through a regulating valve 23, the flow meter 22 detects whether the flow meets the requirement, and then the concentration detector 21 detects the concentration of the gas entering the mixer 20; according to the flow and the concentration of the low-concentration gas, the flow of the high-concentration gas is adjusted and controlled by controlling the regulating valve 8, the proper high-concentration gas is supplemented to meet the gas concentration suitable for combustion power generation, and the proper mixed gas concentration is adjusted and controlled by the flow control valve 8, the valve 23, the first flowmeter 9 and the second flowmeter 22 to meet the requirement of a gas power generation system. The mixing and blending control system 10 respectively controls the quick safety shut-off valve 6, the pressure sensor 7, the regulating valve 8, the flow meter 9, the first control valve 2, the second control valve 4, the valve 23, the second flow meter 22, the concentration detector 21, the emptying valve 15 and the switching valve 17. The mixing and blending control system 10 respectively controls the quick safety shut-off valve 6, the pressure sensor 7, the regulating valve 8, the flow meter 9, the control valve I2, the control valve II 4, the valve 23, the flow meter II 22, the concentration detector 21, the emptying valve 15 and the switching valve 17.
In order to prevent the power generation system 16 from backfiring in the combustion process, a fire retardant component 18 is arranged on a mixer 20, when in a starting stage or a shutdown stage and in a fault linkage state, high-concentration gas intake and low-concentration gas intake are cut off, the system enters a purging program, a low-concentration gas inlet valve 2 is closed at the moment, an air intake switching valve 4 is opened, a generator system shut-off valve 17 is closed, an emptying valve 15 is opened, a gas quick shut-off valve 6 is closed, air is introduced through a water ring pump 26 to perform system purging, and the safety of the system operation is ensured. The invention can utilize low-concentration gas to generate electricity, and simultaneously can recover the waste heat in the smoke exhaust by the waste heat recoverer 12 arranged on the smoke exhaust flue, and produce steam or hot water by the steam coil pipe 11 for civil heating or production heating. The mixer 20 in the air intake system 28 may be connected to a heating furnace 29, and the mixer 20 in the air intake system 28 may be connected to the heating furnace 29 and the gas generator system, respectively.
The high-concentration and low-concentration gas mixed combustion power generation system solves the problem of matching and adjusting the gas concentration in the low-concentration gas combustion power generation process, realizes the mixed safe combustion power generation of the low-concentration gas and the high-concentration gas and the recovery of the waste heat of the flue gas, can be widely applied to the low-concentration gas combustion power generation system, and realizes the efficient safe combustion power generation and the waste heat recovery and utilization of the low-concentration gas.