阅读说明：本技术 一种垃圾填埋气压力及甲烷浓度自动调节系统及方法 (Automatic adjusting system and method for landfill gas pressure and methane concentration ) 是由 郑明奇 袁志发 于 2021-08-24 设计创作，主要内容包括：本发明属于垃圾填埋气处理技术领域,具体涉及一种垃圾填埋气压力及甲烷浓度自动调节系统及方法,该系统包括垃圾填埋场、垃圾填埋气收集系统、甲烷浓度自动调节系统、垃圾填埋气预处理系统、垃圾填埋气压力自动调节系统、垃圾填埋气利用设备和控制模块；所述垃圾填埋气收集系统构建在所述垃圾填埋场上；所述垃圾填埋气收集系统依次与甲烷浓度自动调节系统和垃圾填埋气预处理系统连接；所述垃圾填埋气预处理系统依次与垃圾填埋气压力自动调节系统和垃圾填埋气利用设备连接。本发明能够实现垃圾填埋气在利用过程中压力和甲烷浓度的自动调节,保证垃圾填埋气利用设备的稳定运行,提高垃圾填埋气的利用效率。(The invention belongs to the technical field of landfill gas treatment, and particularly relates to an automatic regulation system and method for landfill gas pressure and methane concentration, wherein the system comprises a landfill site, a landfill gas collection system, an automatic methane concentration regulation system, a landfill gas pretreatment system, an automatic landfill gas pressure regulation system, landfill gas utilization equipment and a control module; the landfill gas collection system is built on the landfill site; the garbage landfill gas collecting system is sequentially connected with the methane concentration automatic adjusting system and the garbage landfill gas pretreatment system; the landfill gas pretreatment system is sequentially connected with the landfill gas pressure automatic regulating system and the landfill gas utilization equipment. The invention can realize the automatic adjustment of the pressure and the methane concentration of the landfill gas in the utilization process, ensure the stable operation of the landfill gas utilization equipment and improve the utilization efficiency of the landfill gas.)

1. An automatic adjusting system for pressure and methane concentration of landfill gas is characterized by comprising a landfill site, a landfill gas collecting system, an automatic adjusting system for methane concentration, a landfill gas pretreatment system, an automatic adjusting system for pressure of landfill gas, landfill gas utilization equipment and a control module; the landfill gas collecting system is constructed on the landfill site to collect landfill gas generated by the landfill site; the landfill gas collection system is sequentially connected with an automatic methane concentration adjusting system and a landfill gas pretreatment system, the automatic methane concentration adjusting system is used for automatically adjusting the methane concentration in the landfill gas, and the landfill gas pretreatment system is used for purifying the landfill gas; the system comprises a garbage landfill gas pretreatment system, a garbage landfill gas utilization device, a methane concentration automatic adjustment system, a garbage landfill gas pretreatment system, a garbage landfill gas pressure automatic adjustment system and a control module, wherein the garbage landfill gas pretreatment system is sequentially connected with the garbage landfill gas automatic adjustment system and the garbage landfill gas utilization device, the garbage landfill gas pressure automatic adjustment system is used for automatically adjusting the garbage landfill gas pressure, and the control module is respectively connected with the methane concentration automatic adjustment system, the garbage landfill gas pretreatment system, the garbage landfill gas pressure automatic adjustment system and the garbage landfill gas utilization device.

2. The automatic landfill gas pressure and methane concentration regulating system of claim 1, wherein the automatic methane concentration regulating system comprises a mechanical three-way valve, an electric regulating valve and an automatic methane concentration regulating pipe; the electric control valve is installed on the methane concentration automatic adjusting pipeline, and one end of the methane concentration automatic adjusting pipeline is connected with the mechanical three-way valve.

3. The automatic landfill gas pressure and methane concentration regulating system of claim 2, wherein the landfill gas collection system comprises a gas collection well, a gas collection new well, a gas collection waste well and a landfill gas delivery pipe; the gas collecting well is connected with a garbage landfill gas conveying pipeline, the gas collecting new well is respectively connected with a methane concentration automatic adjusting pipeline and the garbage landfill gas conveying pipeline through a mechanical three-way valve, the gas collecting waste well is connected with the methane concentration automatic adjusting pipeline, and the garbage landfill gas conveying pipeline is connected with the methane concentration automatic adjusting pipeline; the landfill gas conveying pipeline is connected with an inlet of the landfill gas pretreatment system, and a connection point of the landfill gas conveying pipeline and the methane concentration automatic adjusting pipeline is positioned in front of a connection point of the landfill gas conveying pipeline and the inlet of the landfill gas pretreatment system.

4. The automatic regulating system for pressure and methane concentration in landfill gas according to claim 3, wherein the automatic regulating system for landfill gas pretreatment comprises a first flame arrester, an electric cut-off valve, a coarse filter, a gas-water heat exchanger, a gas-water separation device, a supercharging device, a radiator, a fine filter, a desulfuration device and a second flame arrester, wherein a landfill gas inlet of the first flame arrester is connected with a landfill gas conveying pipeline, and a landfill gas outlet of the first flame arrester is sequentially connected with the electric cut-off valve, the coarse filter, the gas-water heat exchanger, the gas-water separation device, the supercharging device, the radiator, the fine filter, the desulfuration device and the second flame arrester.

5. The automatic landfill gas pressure and methane concentration regulating system of claim 4, wherein the landfill gas pretreatment system further comprises a water collecting well, and the coarse filter, the gas-water heat exchanger, the gas-water separation device, the radiator, the fine filter and the desulfurization device are respectively connected with the water collecting well.

6. The automatic landfill gas pressure and methane concentration regulating system of claim 4, further comprising an online methane analyzer installed on a connection pipe between the desulfurization apparatus and the second flame arrestor.

7. The automatic landfill gas pressure and methane concentration regulating system according to claim 4, wherein the automatic landfill gas pressure regulating system comprises an electric switch valve, a self-operated pressure regulating valve and a pressure sensor, the electric switch valve and the self-operated pressure regulating valve are respectively connected in parallel with a pressure boosting device, and the pressure sensor is installed on an outlet pipeline of the pressure boosting device.

8. An automatic adjustment method of the automatic adjustment system for landfill gas pressure and methane concentration according to any one of claims 1 to 7, comprising the steps of:

step 1, collecting landfill gas

The landfill gas flows to the gas collecting well by means of pressure difference, then is sent to a landfill gas pretreatment system through a landfill gas conveying pipeline, the gas yield of an old gas collecting well gradually loses along with the time, a gas collecting waste well is formed when the methane concentration gradually decreases to an unusable range, and a gas collecting new well needs to be built on a new garbage stack body continuously;

step 2, automatically adjusting the concentration of methane in the landfill gas

The control module automatically adjusts the opening of an electric adjusting valve arranged on a methane concentration automatic adjusting pipeline by PID according to the set methane concentration application range and a methane concentration signal fed back by an online methane analyzer, so that the landfill gas with lower methane concentration in a gas collection new well and a gas collection waste well is mixed with the landfill gas in a landfill gas conveying pipeline, and the methane concentration in the landfill gas is automatically adjusted;

step 3, pretreating the landfill gas

The landfill gas is conveyed to an inlet of a landfill gas pretreatment system through a landfill gas conveying pipeline, a flame arrester I at the inlet prevents possible open fire from entering the landfill gas pretreatment system from an air inlet, enters a coarse filter through an electric cut-off valve, the electric cut-off valve cuts off supply of the landfill gas when receiving an emergency signal, the coarse filter removes partial moisture and larger impurity particles in the landfill gas, the filtered landfill gas enters an air-water heat exchanger to be cooled and cooled, then enters a gas-water separation device to remove most of moisture in the landfill gas, the landfill gas after being cooled and dewatered enters a pressurization device to be pressurized, the temperature is raised, the landfill gas enters a radiator to be cooled and treated, then the fine filter removes tiny impurity particles and partial moisture, and finally the landfill gas enters a desulfurization device to perform desulfurization treatment on sulfides in the landfill gas, the treated landfill gas enters landfill gas utilization equipment, and a flame arrester II is additionally arranged at an outlet of a landfill gas pretreatment system to prevent the landfill gas from entering the landfill gas pretreatment system to generate dangerous hidden danger after being tempered by an air inlet pipeline of the landfill gas utilization equipment;

step 4, automatically adjusting the pressure of the landfill gas

Setting an action pressure value of an electric switch valve as P1, setting an action pressure value of a self-operated pressure regulating valve as P2, and setting a normal use pressure value of the landfill gas as P, wherein P1 is more than P2 is more than P, and when the landfill gas pressure fed back and detected by a pressure sensor is less than the P, the control module frequency-conversion regulating pressurization equipment raises the pressure to the P value; when the landfill gas pressure fed back and detected by the pressure sensor is greater than or equal to a P1 value, the control module controls the electric switch valve to open so that the pressure at the outlet of the pressurization equipment is rapidly reduced, when the pressure is reduced to a P2 value, the control module controls the electric switch valve to close, and meanwhile, the self-operated pressure regulating valve is opened so that the self-operated pressure regulating valve is closed after the pressure at the outlet of the pressurization equipment is continuously reduced to the P value;

step 5, utilization of landfill gas

The landfill gas utilization equipment utilizes the landfill gas which is conveyed by the landfill gas pretreatment system and meets the pressure and the methane concentration after purification treatment.

9. The automatic regulating method of the automatic regulating system for pressure and concentration of methane in refuse landfill according to claim 8, characterized in that, in the initial stage of building the new gas-collecting well, the gas volume and concentration of methane in the new gas-collecting well are lower than the utilization requirement, the mechanical three-way valve is opened, the new gas-collecting well is communicated with the automatic methane concentration regulating pipeline, the new gas-collecting well and the waste gas-collecting well are used for regulating the concentration of methane in the refuse landfill gas, when the gas volume and concentration of methane in the new gas-collecting well reach the utilization requirement, the mechanical three-way valve is switched again, the communication between the new gas-collecting well and the automatic methane concentration regulating pipeline is closed, the communication between the new gas-collecting well and the waste landfill gas conveying pipeline is opened, and at this time, the methane concentration in the refuse landfill gas is regulated only by the waste gas-collecting well.

Technical Field

The invention belongs to the technical field of landfill gas treatment, and particularly relates to a system and a method for automatically adjusting landfill gas pressure and methane concentration.

Background

Landfill gas is a product of long-term accumulation of garbage after a series of degradation reactions, and if the landfill gas is directly discharged into the atmosphere, not only is the ecological environment damaged, but also a fire disaster is easily caused, so that centralized treatment is needed. The most main component of the landfill gas is methane, so that the landfill gas belongs to a combustible gas, and is generally directly treated by a torch, used for boiler combustion or power generation, but the utilization efficiency of the landfill gas in the prior art is not high, mainly because the landfill gas is influenced by a plurality of factors such as pressure, methane concentration, temperature, water content, purity and the like in the utilization process, the factors all need to be pretreated by the landfill gas to reach an optimal combustion value, the stability of the pressure and the methane concentration in the landfill gas utilization process in the current common landfill gas pretreatment system is not easy to adjust, the operation is unstable, the utilization efficiency is low, for example, if one of the boiler devices is suddenly closed or the use end of other landfill gas is caused to cause larger pressure fluctuation of the landfill gas when a plurality of boiler devices are jointly operated, the boiler burner is flamed out, the hearth is exploded, the equipment is shut down, the equipment is difficult to start and the like, the most common pressure stabilizing equipment is a gas cabinet, but the investment cost is relatively high, the occupied area is large, and certain limitation is realized. In addition, the environmental temperature, the weather condition, the season change, the composition of the landfill garbage and the like all influence the methane concentration in the landfill gas, and the change of the methane concentration directly influences the utilization efficiency of the landfill gas, for example, when the methane concentration is low, the boiler burner is flamed out, the equipment is difficult to start, and even the explosion chamber occurs after the start is tried for many times; when the methane concentration becomes high, the landfill gas is not sufficiently combusted, harmful gas in tail gas aggravates environmental pollution, and meanwhile, the phenomenon of explosion of the chamber can also occur, so that potential safety hazards exist. Therefore, it is necessary to develop a new technical route to improve the utilization efficiency of landfill gas.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide a system and a method for automatically adjusting the pressure and the methane concentration of the landfill gas, so that the pressure and the methane concentration of the landfill gas are automatically adjusted in the utilization process, the stable operation of landfill gas utilization equipment is ensured, and the utilization efficiency of the landfill gas is improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a system for automatically adjusting the pressure and the methane concentration of landfill gas, which comprises a landfill site, a landfill gas collecting system, an automatic methane concentration adjusting system, a landfill gas pretreatment system, an automatic landfill gas pressure adjusting system, landfill gas utilization equipment and a control module, wherein the landfill site is provided with a garbage collection chamber; the landfill gas collecting system is constructed on the landfill site to collect landfill gas generated by the landfill site; the landfill gas collection system is sequentially connected with an automatic methane concentration adjusting system and a landfill gas pretreatment system, the automatic methane concentration adjusting system is used for automatically adjusting the methane concentration in the landfill gas, and the landfill gas pretreatment system is used for purifying the landfill gas; the system comprises a garbage landfill gas pretreatment system, a garbage landfill gas utilization device, a methane concentration automatic adjustment system, a garbage landfill gas pretreatment system, a garbage landfill gas pressure automatic adjustment system and a control module, wherein the garbage landfill gas pretreatment system is sequentially connected with the garbage landfill gas automatic adjustment system and the garbage landfill gas utilization device, the garbage landfill gas pressure automatic adjustment system is used for automatically adjusting the garbage landfill gas pressure, and the control module is respectively connected with the methane concentration automatic adjustment system, the garbage landfill gas pretreatment system, the garbage landfill gas pressure automatic adjustment system and the garbage landfill gas utilization device.

Further, the automatic methane concentration adjusting system comprises a mechanical three-way valve, an electric adjusting valve and an automatic methane concentration adjusting pipeline; the electric control valve is installed on the methane concentration automatic adjusting pipeline, and one end of the methane concentration automatic adjusting pipeline is connected with the mechanical three-way valve.

Further, the landfill gas collecting system comprises a gas collecting well, a gas collecting new well, a gas collecting waste well and a landfill gas conveying pipeline; the gas collecting well is connected with a garbage landfill gas conveying pipeline, the gas collecting new well is respectively connected with a methane concentration automatic adjusting pipeline and the garbage landfill gas conveying pipeline through a mechanical three-way valve, the gas collecting waste well is connected with the methane concentration automatic adjusting pipeline, and the garbage landfill gas conveying pipeline is connected with the methane concentration automatic adjusting pipeline; the landfill gas conveying pipeline is connected with an inlet of the landfill gas pretreatment system, and a connection point of the landfill gas conveying pipeline and the methane concentration automatic adjusting pipeline is positioned in front of a connection point of the landfill gas conveying pipeline and the inlet of the landfill gas pretreatment system.

Further, landfill gas pretreatment systems includes spark arrester one, electronic trip valve, coarse filter, air water heat exchanger, gas-water separation equipment, supercharging equipment, radiator, smart filter, sweetener and spark arrester two, the landfill gas entry and the landfill gas pipeline of spark arrester one are connected, and the landfill gas export of spark arrester one is connected with electronic trip valve, coarse filter, air water heat exchanger, gas-water separation equipment, supercharging equipment, radiator, smart filter, sweetener and spark arrester two in proper order.

Further, landfill gas pretreatment systems still includes the sump pit, coarse filter, gas-water heat exchanger, gas-water separation equipment, radiator, smart filter, sweetener are connected with the sump pit respectively.

Further, the automatic methane concentration adjusting system further comprises an online methane analyzer, and the online methane analyzer is installed on a connecting pipeline between the desulfurization equipment and the second flame arrester.

Furthermore, the automatic landfill gas pressure adjusting system comprises an electric switch valve, a self-operated pressure adjusting valve and a pressure sensor, wherein the electric switch valve and the self-operated pressure adjusting valve are respectively connected with the supercharging equipment in parallel, and the pressure sensor is installed on an outlet pipeline of the supercharging equipment.

The invention also provides an automatic regulating method based on the automatic regulating system for the pressure and the methane concentration of the landfill gas, which comprises the following steps:

step 1, collecting landfill gas

The landfill gas flows to the gas collecting well by means of pressure difference, then is sent to a landfill gas pretreatment system through a landfill gas conveying pipeline, the gas yield of an old gas collecting well gradually loses along with the time, a gas collecting waste well is formed when the methane concentration gradually decreases to an unusable range, and a gas collecting new well needs to be built on a new garbage stack body continuously;

step 2, automatically adjusting the concentration of methane in the landfill gas

The control module automatically adjusts the opening of an electric adjusting valve arranged on a methane concentration automatic adjusting pipeline by PID according to the set methane concentration application range and a methane concentration signal fed back by an online methane analyzer, so that the landfill gas with lower methane concentration in a gas collection new well and a gas collection waste well is mixed with the landfill gas in a landfill gas conveying pipeline, and the methane concentration in the landfill gas is automatically adjusted;

step 3, pretreating the landfill gas

The landfill gas is conveyed to an inlet of a landfill gas pretreatment system through a landfill gas conveying pipeline, a flame arrester I at the inlet prevents possible open fire from entering the landfill gas pretreatment system from an air inlet, enters a coarse filter through an electric cut-off valve, the electric cut-off valve cuts off supply of the landfill gas when receiving an emergency signal, the coarse filter removes partial moisture and larger impurity particles in the landfill gas, the filtered landfill gas enters an air-water heat exchanger to be cooled and cooled, then enters a gas-water separation device to remove most of moisture in the landfill gas, the landfill gas after being cooled and dewatered enters a pressurization device to be pressurized, the temperature is raised, the landfill gas enters a radiator to be cooled and treated, then the fine filter removes tiny impurity particles and partial moisture, and finally the landfill gas enters a desulfurization device to perform desulfurization treatment on sulfides in the landfill gas, the treated landfill gas enters landfill gas utilization equipment, and a flame arrester II is additionally arranged at an outlet of a landfill gas pretreatment system to prevent the landfill gas from entering the landfill gas pretreatment system to generate dangerous hidden danger after being tempered by an air inlet pipeline of the landfill gas utilization equipment;

step 4, automatically adjusting the pressure of the landfill gas

Setting an action pressure value of an electric switch valve as P1, setting an action pressure value of a self-operated pressure regulating valve as P2, and setting a normal use pressure value of the landfill gas as P, wherein P1 is more than P2 is more than P, and when the landfill gas pressure fed back and detected by a pressure sensor is less than the P, the control module frequency-conversion regulating pressurization equipment raises the pressure to the P value; when the landfill gas pressure fed back and detected by the pressure sensor is greater than or equal to a P1 value, the control module controls the electric switch valve to open so that the pressure at the outlet of the pressurization equipment is rapidly reduced, when the pressure is reduced to a P2 value, the control module controls the electric switch valve to close, and meanwhile, the self-operated pressure regulating valve is opened so that the self-operated pressure regulating valve is closed after the pressure at the outlet of the pressurization equipment is continuously reduced to the P value;

step 5, utilization of landfill gas

The landfill gas utilization equipment utilizes the landfill gas which is conveyed by the landfill gas pretreatment system and meets the pressure and the methane concentration after purification treatment.

Further, in the initial stage of building the gas collection new well, the gas volume and the methane concentration in the gas collection new well are lower and can not meet the utilization requirements, the mechanical three-way valve is opened, the gas collection new well is communicated with the methane concentration automatic adjusting pipeline, the methane concentration in the landfill gas is adjusted by using the gas collection new well and the gas collection waste well, when the gas volume and the methane concentration in the gas collection new well meet the utilization requirements, the mechanical three-way valve is switched again, the communication between the gas collection new well and the methane concentration automatic adjusting pipeline is closed, the communication between the gas collection new well and the landfill gas conveying pipeline is opened, and at the moment, the methane concentration in the landfill gas is adjusted by using the gas collection waste well only.

Compared with the prior art, the invention has the following advantages:

in order to solve the problem that the normal operation of landfill gas utilization equipment is influenced by the instability of landfill gas pressure and methane concentration in the prior art, and the utilization rate of landfill gas is low, the invention provides an automatic regulation system for landfill gas pressure and methane concentration, a methane concentration automatic regulation system is additionally arranged, a control module automatically regulates the opening of an electric regulating valve arranged on a methane concentration automatic regulation pipeline by PID according to a methane concentration signal fed back by an online methane analyzer, so that the quantity of the landfill gas containing low-concentration methane input into a landfill gas conveying pipeline by a gas collection new well and a gas collection waste well is controlled, the methane concentration is regulated by reasonably utilizing the gas collection new well and the gas collection waste well, and compared with the idle condition, the utilization rate of resources is greatly improved, and the production cost is reduced; the automatic pressure regulating system of the landfill gas is additionally arranged, the control module automatically regulates the supercharging equipment and the electric switch valve according to the pressure signal fed back by the pressure sensor and realizes the automatic control of the pressure by combining the self-operated pressure regulating valve, so that the pressure value of the landfill gas meets the use requirement; the automatic adjusting system for the pressure and the methane concentration of the landfill gas is simple to operate, reliable to operate, low in investment cost, beneficial to environmental protection, capable of obtaining better social benefit and economic benefit and worthy of application and popularization in the market.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic structural view of an automatic regulating system for landfill gas pressure and methane concentration according to an embodiment of the present invention;

fig. 2 is a control schematic diagram of an automatic adjustment system for landfill gas pressure and methane concentration according to an embodiment of the present invention.

The reference numbers in the figures denote:

1. a landfill site;

201. a gas collecting well 202, a gas collecting new well 203, a gas collecting waste well 204 and a refuse landfill gas conveying pipeline;

301. a mechanical three-way valve 302, an electric regulating valve 303, an online methane analyzer 304, and a methane concentration automatic regulating pipeline;

4. the system comprises a landfill gas pretreatment system, a fire arrestor I401, an electric shut-off valve 402, a coarse filter 403, a gas-water heat exchanger 404, a gas-water separation device 405, a supercharging device 406, a radiator 407, a fine filter 408, a desulfurization device 409, a fire arrestor II 410, a water collecting well 411;

501. electric switch valve, 502, self-operated pressure regulating valve, 503, pressure sensor;

6. landfill gas utilizes equipment, 7 control module.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments.

As shown in fig. 1 and fig. 2, the automatic adjusting system for pressure and methane concentration of landfill gas of this embodiment includes a landfill site 1, a landfill gas collecting system, an automatic adjusting system for methane concentration, a landfill gas pre-treatment system 4, an automatic adjusting system for pressure of landfill gas, a landfill gas utilization device 6, and a control module 7; a landfill gas collection system is built on the landfill site 1 and is used for collecting landfill gas generated by the landfill site 1; the garbage landfill gas collecting system is sequentially connected with an automatic methane concentration adjusting system and a garbage landfill gas pretreatment system 4, the automatic methane concentration adjusting system is used for automatically adjusting the methane concentration in the garbage landfill gas, and the garbage landfill gas pretreatment system 4 is used for further purifying the garbage landfill gas with the adjusted methane concentration; the landfill gas pretreatment system 4 is sequentially connected with a landfill gas pressure automatic regulating system and a landfill gas utilization device 6, the landfill gas pressure automatic regulating system is used for automatically regulating the landfill gas pressure, and the treated landfill gas is finally conveyed to the landfill gas utilization device 6 for use. The control module 7 is respectively connected with the automatic methane concentration regulating system, the landfill gas pretreatment system 4, the automatic landfill gas pressure regulating system and the landfill gas utilization equipment 6, and the control module 7 monitors and automatically controls the automatic landfill gas pressure and the automatic methane concentration regulating system. The landfill gas utilization device 6 can be specifically designed according to requirements, such as power generation of a gas generator set, combustion of boiler equipment and the like, and the boiler equipment is adopted for combustion in the example.

The automatic methane concentration adjusting system comprises a mechanical three-way valve 301, an electric adjusting valve 302, an automatic methane concentration adjusting pipeline 304 and an online methane analyzer 303; the landfill gas collecting system comprises a gas collecting well 201, a gas collecting new well 202, a gas collecting waste well 203 and a landfill gas conveying pipeline 204, wherein the number of the gas collecting well 201, the gas collecting new well 202 and the number of the gas collecting waste well 203 can be designed according to the demand of landfill gas. The gas collecting well 201 is connected with a landfill gas conveying pipeline 204, the gas collecting new well 202 is respectively connected with an automatic methane concentration adjusting pipeline 304 and a landfill gas conveying pipeline 204 through a mechanical three-way valve 301, the gas collecting waste well 203 is connected with the automatic methane concentration adjusting pipeline 304, the landfill gas conveying pipeline 204 is connected with the automatic methane concentration adjusting pipeline 304, an electric adjusting valve 302 is installed on the automatic methane concentration adjusting pipeline 304, the landfill gas conveying pipeline 204 is connected with an inlet of a landfill gas pretreatment system 4, and a connection point of the landfill gas conveying pipeline 204 and the automatic methane concentration adjusting pipeline 304 is positioned in front of a connection point of the landfill gas conveying pipeline 204 and the inlet of the landfill gas pretreatment system 4; the opening degree of the electric control valve 302 can be automatically adjusted by the control module 7.

The landfill gas pretreatment system 4 comprises a flame arrester I401, an electric shut-off valve 402, a coarse filter 403, a gas-water heat exchanger 404, a gas-water separation device 405, a supercharging device 406, a radiator 407, a fine filter 408, a desulfuration device 409, a flame arrester II 410 and a water collecting well 411, wherein a landfill gas inlet of the flame arrester I401 is connected with a landfill gas conveying pipeline 204, a landfill gas outlet of the flame arrester I401 is sequentially connected with the electric shut-off valve 402, the coarse filter 403, the gas-water heat exchanger 404, the gas-water separation device 405, the supercharging device 406, the radiator 407, the fine filter 408, the desulfuration device 409 and the flame arrester II 410, the coarse filter 403, the gas-water heat exchanger 404, the gas-water separation device 405, the radiator 407, the fine filter 408 and the desulfuration device 409 are respectively connected with the water collecting well 411, and an outlet of the landfill gas pretreatment system 4 is connected with a landfill gas utilization device 6. The online methane analyzer 303 is installed on a connecting pipeline between the desulfurization device 409 and the second flame arrester 410 and used for feeding back a monitored methane concentration signal to the control module 7.

The automatic landfill gas pressure regulating system comprises an electric switch valve 501, a self-operated pressure regulating valve 502 and a pressure sensor 503, wherein the electric switch valve 501 and the self-operated pressure regulating valve 502 are respectively connected with the supercharging equipment 406 in parallel, and the pressure sensor 503 is installed on an outlet pipeline of the supercharging equipment 406.

The embodiment further provides an automatic adjusting method based on the automatic adjusting system for landfill gas pressure and methane concentration, which comprises the following steps:

step S1, collecting landfill gas

The degradable organic components in the garbage can be subjected to microbial decomposition reaction quickly after being pressed in a garbage landfill, so that aerobic and anaerobic microbes for garbage decomposition mainly come from daily covering layer and final covering layer soil, wastewater treatment digested sludge received by the landfill, recycled percolate and the like, and methane and carbon dioxide gas are generated through a series of reaction processes such as aerobic and anaerobic oxygen. And the percolate of the new landfill area flows into the lower landfill area to allow the original old garbage to be subjected to secondary fermentation, so that more garbage landfill gas is generated. Therefore, it is necessary to arrange landfill gas collecting pipes in the landfill site 1, flow to the gas collecting well 201 by means of pressure difference, and then send to the landfill gas pretreatment system 4 through the landfill gas conveying pipe 204. Over time, the gas production rate of the old gas collection well 201 gradually loses, the methane concentration gradually decreases to an unusable range, and the gas collection waste well 203 becomes, and a new gas collection well 202 needs to be built on a new garbage pile to meet the demand of landfill gas consumption.

It should be noted that, at the initial stage of building the gas collection new well 202, the gas amount and the methane concentration in the gas collection new well 202 need a certain time to reach the utilization requirement (the methane concentration is low), the mechanical three-way valve 301 may be opened, the gas collection new well 202 is communicated with the methane concentration automatic adjustment pipeline 304, the gas collection new well 202 and the gas collection waste well 203 are used to adjust the methane concentration in the landfill gas, when the gas amount and the methane concentration in the gas collection new well 202 reach the utilization requirement, the mechanical three-way valve 301 is switched again, the communication between the gas collection new well 202 and the methane concentration automatic adjustment pipeline 304 is closed, the communication between the gas collection new well 202 and the landfill gas conveying pipeline 204 is opened, and at this time, the methane concentration in the landfill gas is adjusted only by using the gas collection waste well 203.

Step S2, automatically adjusting the concentration of methane in the landfill gas

Control module 7 compares according to the methane concentration signal that sets up methane concentration application scope and online methane analysis appearance 303 feedback, PID automatically regulated installs the opening degree of electrical control valve 302 on methane concentration automatically regulated pipeline 304, make the landfill gas of the lower methane concentration in gas collection new well 202 and the gas collecting waste well 203 mix with the landfill gas in the landfill gas pipeline 204, realize the methane concentration in the automatically regulated landfill gas, ensure boiler equipment steady operation, improve the utilization ratio of landfill gas. In addition, when the concentration of methane in the landfill gas is out of the concentration range required by boiler combustion, the control module 7 controls the boiler equipment to automatically stop according to the methane concentration signal fed back by the online methane analyzer 303, so that the phenomena of insufficient combustion or explosion after multiple automatic start failures of the boiler equipment are prevented.

Step S3, pretreating landfill gas

The landfill gas pretreatment system 4 is mainly used for extracting, purifying and metering landfill gas, and providing a gas source meeting purification indexes for the landfill gas utilization equipment 6. The landfill gas treatment process specifically comprises the following steps: in order to prevent open fire which may exist from entering the landfill gas pretreatment system 4 from an air inlet, a flame arrester 401 is additionally arranged at the inlet, the landfill gas enters a coarse filter 403 through an electric cut-off valve 402, the electric cut-off valve 402 can cut off supply of the landfill gas in time when receiving an emergency signal, the coarse filter 403 removes partial moisture and larger impurity particles in the landfill gas, the filtered landfill gas enters a gas-water heat exchanger 404 to be cooled and cooled, then enters a gas-water separation device 405 to remove most moisture in the landfill gas so as to prevent a large amount of moisture in the landfill gas from forming acid with corrosive gas and corroding equipment and pipelines, and the temperature of the cooled and dewatered landfill gas rises after the landfill gas enters a pressurization device 406 to be pressurized, the waste landfill gas enters a radiator 407 for cooling treatment, then is subjected to fine impurity particles and partial moisture removal through a fine filter 408, finally enters a desulfurization device 409 for desulfurization treatment of sulfide in the waste landfill gas, so that the waste landfill gas is prevented from forming acid after being combusted and corroding a boiler and pipeline equipment, the treated waste landfill gas enters a waste landfill gas utilization device 6, and in addition, a second flame arrester 410 is additionally arranged at an outlet of the waste landfill gas pretreatment system 4 to prevent the waste landfill gas utilization device 6 from entering the waste landfill gas pretreatment system 4 after being tempered in an air inlet pipeline to cause danger.

Step S4, automatically adjusting the pressure of the landfill gas

The pressure value of the electric switch valve 501 is set to be P1, the pressure value of the self-operated pressure regulating valve 502 is set to be P2, and the normal use pressure value of the landfill gas is set to be P, wherein P1 is greater than P2 is greater than P, and the pressure of the landfill gas can be unstable due to the use end of the landfill gas, so the system needs to stabilize the pressure of the landfill gas.

When the pressure of the landfill gas fed back and detected by the pressure sensor 503 is smaller than the P value, the control module 7 adjusts the rotation speed of the supercharging equipment 406 by frequency conversion, and the pressure is increased to about the P value; when the landfill gas pressure detected by the pressure sensor 503 in a feedback manner is greater than or equal to the value P1, the pressure increasing device 406 does not respond timely, the pressure at the outlet of the pressure increasing device 406 increases instantly, the control module 7 controls the electric switch valve 501 to open, so that the pressure at the outlet of the pressure increasing device 406 is reduced rapidly, when the pressure is reduced to the value P2, the control module 7 controls the electric switch valve 501 to close, and the self-operated pressure regulating valve 502 is opened, so that after the pressure at the outlet of the pressure increasing device 406 is continuously reduced to the value P, the self-operated pressure regulating valve 502 is closed, and the automatic regulation of the landfill gas pressure is completed. In the embodiment, the pressure value of the landfill gas is adjusted in stages, firstly, the electric switch valve 501 is used for pressure relief, and then, the self-operated pressure adjusting valve 502 is used for finely adjusting the pressure, so that the pressure is continuously reduced to the preset pressure value.

Step S5, utilization of landfill gas

The landfill gas utilization equipment 6 is used for utilizing the landfill gas which is conveyed by the landfill gas pretreatment system 4 and meets the pressure and the methane concentration after purification treatment, and the most common utilization mode of the landfill gas is to use a gas generator set for power generation or a boiler device for combustion heat supply, but the utilization mode is not limited to the two modes.

The automatic regulating system and the method of the automatic regulating system for the pressure and the concentration of the landfill gas can realize the automatic regulation of the pressure and the concentration of the methane, ensure the continuous, stable and safe operation of the landfill gas utilization equipment 6, improve the utilization efficiency of the landfill gas, improve the economic benefit, simultaneously avoid the environmental pollution caused by the direct discharge of the landfill gas into the atmosphere, and are beneficial to environmental protection. The invention reasonably utilizes the gas collection new well 202 and the gas collection waste well 203 to adjust the concentration of methane, further improves the resource utilization rate compared with the idle condition, changes the lower concentration methane generated by the gas collection new well 202 and the gas collection waste well 203 into valuable, and reduces the production cost.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Finally, it is to be noted that: the above description is only a preferred embodiment of the present invention, and is only used to illustrate the technical solutions of the present invention, and not to limit the protection scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.