Skid-mounted low-concentration gas flameless oxidation power generation system and method

Abstract

The invention discloses a skid-mounted low-concentration gas flameless oxidation power generation system and method, and relates to the technical field of coal mine gas efficient utilization, the system comprises a gas treatment module, a superheater, a power generation module, a flue gas purification module and a dead steam treatment module, and each module adopts a skid-mounted structure; the gas treatment module is used for carrying out flameless oxidation on low-concentration gas to obtain high-temperature flue gas and carrying out heat exchange on the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam, the superheater is used for heating the saturated steam to obtain superheated steam, and the power generation module is used for generating power based on the superheated steam to obtain dead steam and electric energy; the flue gas purification module is used for purifying low-temperature flue gas to obtain dischargeable flue gas, the dead steam treatment module is used for treating dead steam to obtain low-temperature water, and the low-temperature water is conveyed to the gas treatment module. According to the invention, the problems of poor utilization rate, environmental pollution, large project investment and high operation cost of traditional gas flameless oxidation power generation can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of efficient utilization of coal mine gas, and particularly to a skid-mounted flameless oxidation power generation system and method for low-concentration gas. Background Art

[0002] In order to reasonably solve the safety problems in coal mine shafts, the method of gas drainage is usually adopted to reasonably reduce the air-drained gas to a safe concentration below 1%. However, during the gas drainage process, due to the single form of gas drainage, more air is mixed in, and the drainage volume fluctuates greatly, resulting in most of the drained gas having a concentration lower than 30%. Among them, the low-concentration gas with a concentration lower than 8% accounts for more than 70% of the total drainage volume. This part of the low-concentration gas is within the explosion concentration range, and it is very difficult to stably burn it by conventional combustion methods to achieve efficient utilization, and it can only be discharged into the atmospheric environment.

[0003] The main component of gas is methane, whose greenhouse effect is equivalent to 24.6 times that of CO2, and its ability to damage the atmospheric ozone layer is equivalent to 7 times that of CO2. Every year, a large amount of low-concentration gas gushes out and cannot be efficiently utilized, which not only causes serious waste of limited non-renewable resources, but also exacerbates air pollution and the greenhouse effect. With the continuous progress of the flameless oxidation power generation technology for gas, the regenerative flameless oxidation power generation technology has gradually matured and been applied. Based on the technology of improving the heat storage capacity, the low-concentration gas with a concentration below 8% extracted from coal mines can be mixed with air-drained gas or air to a concentration of 1.0% - 1.2% for oxidation power generation to achieve the utilization of low-concentration gas. However, there are the following problems in the flameless oxidation power generation of gas: (1) Poor utilization rate and environmental pollution; (2) Large project investment: Compared with general coalbed methane (gas) power generation projects, the investment is larger and the construction period is longer; (3) High operating cost: The daily maintenance volume is large, and professional technical personnel and equipment are required, increasing the labor and material costs. At the same time, the wear and replacement of equipment will also bring certain cost pressures. Summary of the Invention

[0004] The purpose of the present application is to provide a skid-mounted flameless oxidation power generation system and method for low-concentration gas, which can solve the problems of poor utilization rate, environmental pollution, large project investment, and high operating cost existing in traditional flameless oxidation power generation of gas.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] In a first aspect, the present application provides a skid-mounted flameless oxidation power generation system for low-concentration gas, including: a gas treatment module, a superheater, a power generation module, a flue gas purification module, and an exhaust steam treatment module. The gas treatment module, the superheater, the power generation module, the flue gas purification module, and the exhaust steam treatment module all adopt a skid-mounted structure;

[0007] The gas treatment module is used for flameless oxidation of low-concentration gas to obtain high-temperature flue gas, and exchanges heat between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam; the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature water, and the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature flue gas;

[0008] The superheater is used for heating the saturated steam to obtain superheated steam;

[0009] The power generation module is used for generating electricity based on the superheated steam to obtain exhaust steam and electric energy;

[0010] The flue gas purification module is used for purifying the low-temperature flue gas to obtain flue gas that can be discharged;

[0011] The exhaust steam treatment module is used for treating the exhaust steam to obtain low-temperature water, and conveys the low-temperature water to the gas treatment module.

[0012] Optionally, the configured quantity of the gas treatment module is determined based on the intake volume and concentration of low-concentration gas, where n1 is the configured quantity of the gas treatment module, is the ceiling function, V is the intake volume of low-concentration gas, and C is the concentration of low-concentration gas;

[0013] The operating quantity of the gas treatment module is determined based on the intake volume and concentration of low-concentration gas, where n2 is the operating quantity of the gas treatment module;

[0014] One superheater corresponds to two gas treatment modules, and the superheater is used for heating the saturated steam obtained by the two gas treatment modules corresponding to the superheater to obtain superheated steam.

[0015] Optionally, the gas treatment module includes: a gas pretreatment unit, a flameless oxidation device for gas, and a waste heat boiler;

[0016] The gas pretreatment unit is used for pretreating low-concentration gas to obtain pretreated gas;

[0017] The flameless oxidation device for gas is used for flameless oxidation of the pretreated gas to obtain high-temperature flue gas;

[0018] The waste heat boiler is used for exchanging heat between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam, and receives the low-temperature water conveyed by the exhaust steam treatment module.

[0019] Optionally, the gas pre-treatment unit includes: a redundant safety control sub-unit, a multi-stage dehydration sub-unit, and a dynamic pressure boosting and regulating sub-unit that are connected in sequence;

[0020] The redundant safety control sub-unit includes: a first controller, a methane concentration sensor, and a pneumatic cut-off valve. The methane concentration sensor is installed at the air inlet of the multi-stage dehydration sub-unit, and the pneumatic cut-off valve is installed on the air inlet pipeline of the multi-stage dehydration sub-unit; the methane concentration sensor is used to detect the methane concentration in the low-concentration gas, and the first controller is used to control the pneumatic cut-off valve to close when the duration of the methane concentration being greater than the upper limit of the methane concentration is greater than the upper limit of the duration, so as to prohibit the low-concentration gas from entering the multi-stage dehydration sub-unit;

[0021] The multi-stage dehydration sub-unit includes: a rough dehydration device, a fine dehydration device, and a self-cleaning filter that are connected in sequence;

[0022] The dynamic pressure boosting and regulating sub-unit includes: a second controller, a two-channel Roots booster, a pressure sensor, and an anti-surge reflux valve. The pressure sensor is installed at the air outlet of the two-channel Roots booster, and the anti-surge reflux valve is installed on the connecting pipeline. The connecting pipeline is a pipeline for connecting the air inlet and the air outlet of the two-channel Roots booster; the pressure sensor is used to detect the pressure of the air outlet, and the second controller is used to control the rotation speed of the two-channel Roots booster and the opening and closing of the anti-surge reflux valve based on the pressure. When the anti-surge reflux valve is opened, a part of the air outlet of the two-channel Roots booster flows back to the air inlet of the two-channel Roots booster.

[0023] Optionally, the methane concentration sensor includes: a laser methane sensor, an infrared sensor, and a catalytic combustion sensor;

[0024] The laser methane sensor is used to detect the methane concentration in the low-concentration gas to obtain a first methane concentration;

[0025] The infrared sensor is used to detect the methane concentration in the low-concentration gas to obtain a second methane concentration;

[0026] The catalytic combustion sensor is used to detect the methane concentration in the low-concentration gas to obtain a third methane concentration;

[0027] The first controller is configured to determine whether the absolute value of the difference between the first methane concentration and the third methane concentration is less than a preset difference, so as to obtain a first determination result. If the first determination result is yes, the first methane concentration is used as the methane concentration detected by the methane concentration sensor. If the first determination result is no, it is determined whether the absolute value of the difference between the second methane concentration and the third methane concentration is less than the preset difference, so as to obtain a second determination result. If the second determination result is yes, the second methane concentration is used as the methane concentration detected by the methane concentration sensor.

[0028] Optionally, the flameless oxidation device for gas includes: a third controller, an oxidation chamber, an outer thermal insulation layer, and an auxiliary heating component;

[0029] The outer thermal insulation layer wraps the oxidation chamber, and a molten salt is filled between the outer thermal insulation layer and the oxidation chamber;

[0030] The third controller is configured to control the auxiliary heating component to be turned on to raise the temperature of the oxidation chamber to a preset temperature when the concentration of the pretreated gas is less than a preset concentration; wherein, the auxiliary heating component uses fuel-assisted heating or electric-assisted heating.

[0031] Optionally, the heating surface in the flue gas inlet section of the waste heat boiler uses plain tubes, and the heating surface in the flue gas outlet section of the waste heat boiler uses corrugated tubes or finned tubes.

[0032] Optionally, when the configured quantity of the gas treatment module is less than or equal to 3, the power generation module uses a power generation device based on low-temperature waste heat power generation by an organic Rankine cycle or a power generation device based on a screw expander; when the configured quantity of the gas treatment module is greater than or equal to 4, the power generation module uses a power generation device based on a steam turbine.

[0033] Optionally, the exhaust steam treatment module includes: a condensation unit and a water treatment unit;

[0034] The condensation unit is configured to perform condensation treatment on the exhaust steam to obtain condensed water;

[0035] The water treatment unit is configured to treat the water quality of the condensed water to obtain low-temperature water, and convey the low-temperature water to the gas treatment module.

[0036] In a second aspect, the present application provides a skid-mounted flameless oxidation power generation method for low-concentration gas, which works based on the above-mentioned skid-mounted flameless oxidation power generation system for low-concentration gas, and includes:

[0037] The gas treatment module conducts flameless oxidation on low-concentration gas to obtain high-temperature flue gas, and exchanges heat between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam; the temperature of the high-temperature flue gas is higher than that of the low-temperature water, and the temperature of the high-temperature flue gas is higher than that of the low-temperature flue gas;

[0038] The superheater heats the saturated steam to obtain superheated steam;

[0039] The power generation module generates electricity based on the superheated steam to obtain exhausted steam and electric energy;

[0040] The flue gas purification module purifies the low-temperature flue gas to obtain flue gas that can be discharged;

[0041] The exhausted steam treatment module treats the exhausted steam to obtain low-temperature water, and transports the low-temperature water to the gas treatment module.

[0042] According to the specific embodiments provided in this application, this application has the following technical effects:

[0043] This application provides a skid-mounted low-concentration gas flameless oxidation power generation system and method. The gas treatment module conducts flameless oxidation on low-concentration gas to obtain high-temperature flue gas, and exchanges heat between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam. The superheater heats the saturated steam to obtain superheated steam. The power generation module generates electricity based on the superheated steam to obtain exhausted steam and electric energy. The flue gas purification module purifies the low-temperature flue gas to obtain flue gas that can be discharged. The exhausted steam treatment module treats the exhausted steam to obtain low-temperature water, and transports the low-temperature water to the gas treatment module. By setting up the exhausted steam treatment module in this application, the exhausted steam obtained after power generation can be processed into low-temperature water again and sent to the gas treatment module for recycling, which can improve the utilization rate. By setting up the flue gas purification module, the low-temperature flue gas can be treated into flue gas that can be discharged before being discharged, avoiding environmental pollution and being more environmentally friendly. Moreover, by setting up the gas treatment module, superheater, power generation module, flue gas purification module and exhausted steam treatment module all adopt skid-mounted structures, which can be flexibly arranged and are convenient to be transported to a coal mine for installation. Compared with the traditional scheme in which each module of the gas flameless oxidation power generation forms a whole, there is no need to reconstruct each module in the coal mine, which can reduce investment and shorten the construction period. At the same time, since each module adopts a skid-mounted structure, each module is independent and can be locally overhauled. Compared with the traditional scheme in which each module of the gas flameless oxidation power generation forms a whole, since the whole needs to be shut down for overhaul, while each module can be independently repaired one by one without affecting the use, the maintenance amount is smaller than that of the overall shutdown overhaul, and only the faulty module can be replaced without replacing the whole, which can reduce the operation cost, thus solving the problems of poor utilization rate, environmental pollution, large project investment and high operation cost existing in the traditional gas flameless oxidation power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0045] Figure 1 FIG. is a schematic structural diagram of a skid-mounted flameless oxidation power generation system for low-concentration gas provided in Embodiment 1 of the present application.

[0046] Figure 2 FIG. is a schematic flow diagram of a skid-mounted flameless oxidation power generation method for low-concentration gas provided in Embodiment 2 of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0048] Embodiment 1

[0049] As a high-quality energy source, the calorific value of gas combustion is about 35000 kJ / Nm 3 , which is equivalent to that of conventional natural gas and can be used as fuel and chemical raw materials, etc. Since oxygen is a combustible auxiliary agent, the introduction of oxygen increases the explosion risk of coalbed methane and brings great difficulties to the processing and transportation of coalbed methane. At present, the categories, proportions, utilization rates and main utilization methods of extracted coalbed methane are as follows: high-concentration gas (>30%) accounts for about 6%, and the utilization rate exceeds 90%. Low-concentration gas accounts for about 94%, but the utilization rate is lower than 35%. Due to the too low gas concentration in low-concentration gas, its utilization is difficult. Its main utilization methods are regenerative oxidation and co-firing power generation with high-concentration gas, and the utilization rates of these methods are also relatively low. As a result, most of the low-concentration gas is directly discharged into the atmosphere, causing huge resource waste. At the same time, the environment has also been greatly damaged.

[0050] Aiming at the problems of poor utilization rate, environmental pollution, large project investment and high operating cost existing in traditional flameless oxidation power generation of gas, this embodiment provides a skid-mounted flameless oxidation power generation system for low-concentration gas, as shown in Figure 1As shown in the figure, it includes: a gas treatment module, a superheater, a power generation module, a flue gas purification module, and a waste steam treatment module. The gas treatment module, the superheater, the power generation module, the flue gas purification module, and the waste steam treatment module all adopt a skid-mounted structure. The skid-mounted structure is an integration method that integrates functional components on an integral base, which is convenient for overall installation and movement, and has the advantages of being flexible, small in volume, small in floor area, and convenient for migration. In this embodiment, the gas treatment module, the superheater, the power generation module, the flue gas purification module, and the waste steam treatment module are respectively installed on the base, so that the gas treatment module, the superheater, the power generation module, the flue gas purification module, and the waste steam treatment module are independent of each other and can realize independent installation, movement, and maintenance.

[0051] The gas treatment module is used for flameless oxidation of low-concentration gas (concentration < 8%) to obtain high-temperature flue gas, and heat exchange the high-temperature flue gas with low-temperature water to obtain low-temperature flue gas and saturated steam. Among them, the temperature of the high-temperature flue gas is higher than the temperature of the low-temperature water, and the temperature of the high-temperature flue gas is higher than the temperature of the low-temperature flue gas.

[0052] The superheater is used for heating the saturated steam to obtain superheated steam.

[0053] The power generation module is used for generating electricity based on the superheated steam to obtain waste steam (low-grade steam with a certain pressure and temperature discharged after the superheated steam does work) and electric energy.

[0054] The flue gas purification module is used for purifying the low-temperature flue gas to obtain flue gas that can be discharged.

[0055] The waste steam treatment module is used for treating the waste steam to obtain low-temperature water and transporting the low-temperature water to the gas treatment module.

[0056] The following is a detailed introduction to each module of this embodiment:

[0057] (1) Gas treatment module

[0058] In this embodiment, the configuration quantity (that is, the number of gas treatment modules to be built) and the operation quantity (that is, the number of gas treatment modules to be operated simultaneously) of the gas treatment module are designed according to the product of the intake volume V and the concentration C of the low-concentration gas. The configuration quantity refers to how many gas treatment modules need to be configured for the low-concentration gas generated by the current coal mine, and the operation quantity refers to how many gas treatment modules need to be started for the low-concentration gas to be processed at the current time. The operation quantity is less than the configuration quantity. By setting the configuration quantity and the operation quantity of the gas treatment module, the low-concentration gas can be matched with the power of the flameless oxidation device in the gas treatment module.

[0059] The configuration quantity of the gas treatment module is determined based on the intake volume and concentration of the low-concentration gas. Among them, n1 is the configured quantity of the gas treatment module, is the ceiling function, V is the intake volume of low-concentration gas, and C is the concentration of low-concentration gas. For example, when 10×V×C ≤ 4500, one set of gas treatment modules is configured; when 4500 < 10×V×C ≤ 9000, two sets of gas treatment modules are configured.

[0060] To improve efficiency, when the configured quantity of the gas treatment module is 1, it is recommended to adopt methods such as direct steam supply, absorption heating / cooling, vacuum phase change direct heating unit, absorption heat pump, etc., to utilize the heat of the high-temperature flue gas generated by the flameless oxidation device in the gas treatment module. Direct steam supply means directly heating water through a heat exchanger with the heat of the high-temperature flue gas generated by the flameless oxidation device to produce steam for industrial production or domestic use. Direct absorption heating / cooling means using the heat of the high-temperature flue gas generated by the flameless oxidation device as the driving heat source to drive the absorption refrigeration or heating cycle. Direct vacuum phase change direct heating unit means directly heating a certain working medium in a vacuum environment with the heat of the high-temperature flue gas generated by the flameless oxidation device to cause its phase change, thereby realizing the efficient transfer and utilization of heat. Direct absorption heat pump means using the heat of the high-temperature flue gas generated by the flameless oxidation device as the driving energy source, and pumping the heat of the low-temperature heat source to the high-temperature heat user through an absorption cycle to realize the upgraded utilization of heat.

[0061] According to the intake volume V and concentration C of the low-concentration gas, the gas treatment modules can operate independently, that is, only one set of gas treatment modules operates, or they can operate jointly, that is, at least two sets of gas treatment modules operate. The operating quantity of the gas treatment modules is determined based on the intake volume and concentration of the low-concentration gas. Among them, n2 is the operating quantity of the gas treatment modules.

[0062] One set of gas treatment modules in this embodiment consists of a gas pretreatment unit, a flameless oxidation device, and a waste heat boiler. The gas pretreatment unit is used to improve the gas quality and increase the power generation efficiency.

[0063] At this time, in this embodiment, the gas treatment module includes: a gas pretreatment unit, a flameless oxidation device, and a waste heat boiler. The gas pretreatment unit is used to pre-treat the low-concentration gas to obtain pre-treated gas. The flameless oxidation device is used to perform flameless oxidation on the pre-treated gas to obtain high-temperature flue gas. The waste heat boiler is used to exchange heat between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam, and receive the low-temperature water transported by the exhaust steam treatment module.

[0064] The following is a detailed introduction to the gas pretreatment unit, the flameless oxidation device, and the waste heat boiler:

[0065] (1) Gas pretreatment unit

[0066] The gas pretreatment unit of this embodiment integrates functions such as redundant safety control, multi-stage dehydration, and dynamic pressure boost regulation, and solves problems such as potential safety hazards, incomplete dehydration, and unstable pressure boost in the utilization of low-concentration gas. Specifically, the gas pretreatment unit of this embodiment includes: a redundant safety control subunit, a multi-stage dehydration subunit, and a dynamic pressure boost regulation subunit that are connected in sequence.

[0067] The redundant safety control subunit of this embodiment has a fast blocking function. Specifically, a pneumatic cut-off valve (action time ≤ 0.5 s) is set. When the methane concentration in the low-concentration gas exceeds 10% for a long time (for example, the duration > 5 min), the pneumatic cut-off valve is controlled to close to cut off the intake air.

[0068] At this time, in this embodiment, the redundant safety control subunit includes: a first controller, a methane concentration sensor, and a pneumatic cut-off valve. The methane concentration sensor is installed at the intake port of the multi-stage dehydration subunit, and the pneumatic cut-off valve is installed on the intake pipeline of the multi-stage dehydration subunit. The methane concentration sensor is used to detect the methane concentration in the low-concentration gas. The first controller is used to control the pneumatic cut-off valve to close to prohibit the low-concentration gas from entering the multi-stage dehydration subunit when the duration of the methane concentration being greater than the methane concentration upper limit (for example, 10%) is greater than the duration upper limit (for example, 5 min).

[0069] The methane concentration sensor of this embodiment adopts three-level concentration monitoring. Specifically, a laser methane sensor (response time < 1 s), an infrared sensor, and a catalytic combustion sensor are set. The methane concentration detected by the catalytic combustion sensor is used as a standard to correct the methane concentration detected by the laser methane sensor and the methane concentration detected by the infrared sensor. If the positive and negative deviation between the methane concentration detected by the laser methane sensor and the methane concentration detected by the catalytic combustion sensor is less than 5%, then the methane concentration detected by the laser methane sensor is used as the finally output methane concentration, and subsequently the first controller controls the pneumatic cut-off valve based on the finally output methane concentration. Otherwise, it is considered that the laser methane sensor is damaged. If the positive and negative deviation between the methane concentration detected by the infrared sensor and the methane concentration detected by the catalytic combustion sensor is less than 5%, then the methane concentration detected by the infrared sensor is used as the finally output methane concentration, and subsequently the first controller controls the pneumatic cut-off valve based on the finally output methane concentration. Otherwise, it is considered that the infrared sensor is also damaged. At this time, both the laser methane sensor and the infrared sensor are damaged, and shutdown maintenance is required.

[0070] At this time, in this embodiment, the methane concentration sensor includes a laser methane sensor, an infrared sensor, and a catalytic combustion sensor. The laser methane sensor is used to detect the methane concentration in low-concentration gas to obtain a first methane concentration. The infrared sensor is used to detect the methane concentration in low-concentration gas to obtain a second methane concentration. The catalytic combustion sensor is used to detect the methane concentration in low-concentration gas to obtain a third methane concentration. The first controller is used to determine whether the absolute value of the difference between the first methane concentration and the third methane concentration is less than a preset difference (such as 5%) to obtain a first judgment result. If the first judgment result is yes, the first methane concentration is used as the methane concentration detected by the methane concentration sensor. If the first judgment result is no, it is determined whether the absolute value of the difference between the second methane concentration and the third methane concentration is less than a preset difference (such as 5%) to obtain a second judgment result. If the second judgment result is yes, the second methane concentration is used as the methane concentration detected by the methane concentration sensor. If the second judgment result is no, it is considered that both the laser methane sensor and the infrared sensor are damaged and shutdown maintenance is required.

[0071] The redundant safety control sub-unit of this embodiment also has a nitrogen injection function. When the duration for which the methane concentration detected by the methane concentration sensor is greater than the methane concentration upper limit is greater than the duration upper limit, after controlling the pneumatic cut-off valve to close, high-pressure nitrogen (purity ≥ 99.999%) can be instantaneously injected into the intake pipeline to dilute the low-concentration gas and reduce the methane concentration in the low-concentration gas to a safe concentration, where the safe concentration is a concentration less than the methane concentration upper limit.

[0072] The multi-stage dehydration sub-unit of this embodiment includes rough dehydration, fine dehydration, a self-cleaning filter, etc.

[0073] At this time, in this embodiment, the multi-stage dehydration sub-unit includes: a rough dehydration device, a fine dehydration device, and a self-cleaning filter connected in sequence. The main purpose of the rough dehydration device is to remove most of the liquid water and a part of the gaseous water in the low-concentration gas and reduce the humidity of the gas. For example, methods such as the cyclone separator method and the condensation method can be used for rough dehydration. The fine dehydration device further reduces the water content in the low-concentration gas on the basis of the rough dehydration device to make it reach a higher dryness. For example, methods such as absorption dehydration and desiccant dehydration can be used for fine dehydration. The self-cleaning filter is used to remove impurities in the low-concentration gas, such as dust, tar, acids, etc., to protect the subsequent equipment from pollution and blockage and ensure the cleanliness of the gas. For example, the self-cleaning filter mainly consists of a filter screen, a backwashing device, and a differential pressure controller, etc. When the gas passes through the filter screen, the impurities are intercepted by the filter screen. As the impurities accumulate, the differential pressure across the filter screen gradually increases. When the differential pressure reaches the set value, the differential pressure controller sends a signal to start the backwashing device to clean the filter screen, wash away and discharge the intercepted impurities, and restore the filtering performance of the filter screen.

[0074] The dynamic pressure boosting and regulating subunit of this embodiment includes a two-channel Roots booster, a pressure closed-loop control function for controlling the rotational speed of the two-channel Roots booster, and an anti-surge function based on an anti-surge reflux valve to prevent the two-channel Roots booster from surging. The two-channel Roots booster operates by parallel connection of two Roots blowers to achieve the boosting of gas. The pressure closed-loop control function is to install a pressure sensor at the outlet of the two-channel Roots booster to monitor the outlet pressure in real time, transmit the detected outlet pressure to the controller, and the controller automatically adjusts the rotational speed of the two-channel Roots booster through PID (Proportional-Integral-Derivative) control based on the set outlet pressure and the detected outlet pressure, so as to achieve precise control of the outlet pressure, ensure the pressure stability of the gas during transportation and utilization, and avoid equipment failures and safety hazards caused by pressure fluctuations. The anti-surge function is that when the gas flow rate or pressure fluctuates and may cause the two-channel Roots booster to surge, the anti-surge reflux valve will open, returning a part of the gas from the outlet to the inlet to increase the inlet gas volume and prevent surging from occurring.

[0075] At this time, in this embodiment, the dynamic pressure boosting and regulating subunit includes: a second controller, a two-channel Roots booster, a pressure sensor, and an anti-surge reflux valve. The pressure sensor is installed at the outlet of the two-channel Roots booster, and the anti-surge reflux valve is installed on the connecting pipe, and the connecting pipe is a pipe for connecting the inlet and outlet of the two-channel Roots booster. The pressure sensor is used to detect the outlet pressure of the outlet, and the second controller is used to control the rotational speed of the two-channel Roots booster based on the pressure (specifically calculate the difference between the pressure and the preset pressure target value, and perform PID control based on the difference) and the opening and closing of the anti-surge reflux valve (specifically, when the change value of the pressure is greater than the preset change value, control the anti-surge reflux valve to open). After the anti-surge reflux valve opens, a part of the outlet gas at the outlet of the two-channel Roots booster flows back to the inlet of the two-channel Roots booster.

[0076] In this embodiment, dehydration can be carried out first and then pressure regulation. At this time, the multi-stage dehydration subunit is before the dynamic pressure boosting and regulating subunit. It is also possible to carry out pressure regulation first and then dehydration. At this time, the dynamic pressure boosting and regulating subunit is before the multi-stage dehydration subunit.

[0077] (2) Gas flameless oxidation device

[0078] The power of the gas flameless oxidation device of this embodiment can be 3000 - 4000 kW, with a 10% power redundancy, and can operate stably when the concentration of low-concentration gas is in the range of 1% - 8% concentration. The corresponding gas inlet volume provided by the gas treatment module is 5000 - 30000 Nm 3 / h, and can adapt to the changes in the inlet gas volume and concentration of the pretreated gas.

[0079] The flameless oxidation device for gas can adopt direct current jet flameless oxidation, swirl jet flameless oxidation or porous medium regenerative oxidation. Molten salt is filled between the oxidation chamber and the outer insulation layer of the flameless oxidation device for gas to improve the heat storage capacity of the flameless oxidation device for gas. Moreover, the flameless oxidation device for gas is equipped with a closed-loop controlled ignition system and an auxiliary heating system to ensure the safe and stable progress of the oxidation reaction. The closed-loop control of the ignition system means that the ignition combustion is monitored through devices such as knock sensors, and the signal of the combustion condition is transmitted to the control unit. The control unit makes real-time corrections to parameters such as ignition advance angle and ignition energy according to the received signal, so that the ignition time and energy are always in the best state, ensuring stable ignition of the flameless oxidation device for gas and maintaining good combustion efficiency. The auxiliary heating system is in the initial stage of the oxidation reaction or when the gas concentration is relatively low, etc. Only relying on the heat generated by the gas oxidation itself may not be sufficient to maintain the temperature required for the reaction. At this time, the auxiliary heating system is started to input additional heat into the flameless oxidation device for gas, so that the reaction system quickly reaches or maintains at an appropriate reaction temperature, ensuring the smooth progress of the oxidation reaction.

[0080] The working process of the auxiliary heating system is as follows: when the concentration of the pretreated gas is less than 4.5%, it is necessary to increase the temperature of the oxidation chamber to 800°C through the auxiliary heating system. The auxiliary heating system can adopt at least one of fuel assistance or electric auxiliary heating. Fuel assistance means burner heating. The fuel at this time can be fuels such as gasoline, diesel, methanol, natural gas, etc. The fuel is ignited through the ignition system to increase the temperature of the oxidation chamber. When the temperature of the oxidation chamber reaches 800°C, the ignition system of the flameless oxidation device for gas is turned on, and then the pretreated gas is introduced into the oxidation chamber and ignited to carry out flameless oxidation; when the concentration of the pretreated gas is greater than or equal to 4.5%, it is necessary to carry out purging through a two-channel Roots supercharger. When methane cannot be detected, the ignition system of the flameless oxidation device for gas is turned on, and then the pretreated gas is introduced into the oxidation chamber and ignited. The flow rate and pressure of the pretreated gas are gradually changed to increase the high-temperature flue gas reflux ratio, so that the flameless oxidation device for gas is in a flameless oxidation state to carry out flameless oxidation. In particular, the concentration of the pretreated gas that can be directly ignited is 4.5% - 5.0%.

[0081] At this time, in this embodiment, the flameless oxidation device for gas includes: a third controller, an oxidation chamber, an outer insulation layer and an auxiliary heating component. The outer insulation layer wraps the oxidation chamber, and molten salt is filled between the outer insulation layer and the oxidation chamber. The third controller is used to control the auxiliary heating component to turn on and increase the temperature of the oxidation chamber to a preset temperature (which can be 800°C) when the concentration of the pretreated gas is less than a preset concentration (which can be 4.5%). Among them, the auxiliary heating component adopts fuel-assisted heating or electric-assisted heating.

[0082] (3) Waste heat boiler

[0083] The waste heat boiler can be a saturated steam boiler with a rated evaporation capacity of 4 - 5 tons. The heating surface of the waste heat boiler refers to the surface of those components that can absorb waste heat and be used to generate steam or hot water. In the waste heat boiler, the heating surface near the high-temperature flue gas inlet section uses plain tubes, and the heating surface near the low-temperature flue gas outlet section uses corrugated tubes or finned tubes, which can enhance the heat transfer effect. For users with heating requirements, the heat source for heating can directly use the saturated steam generated by the waste heat boiler.

[0084] At this time, in this embodiment, the heating surface of the waste heat boiler in the flue gas inlet section uses plain tubes, and the heating surface of the waste heat boiler in the flue gas outlet section uses corrugated tubes or finned tubes.

[0085] (II) Superheater

[0086] In this embodiment, two independent modules are used to generate saturated steam and superheated steam. Specifically, saturated steam is generated by the waste heat boiler, and superheated steam is generated by the superheater, which can be more flexible and reduce costs. This is because if only the waste heat boiler is used to generate superheated steam, the structure of the waste heat boiler will be more complex and the cost will be higher. The heat required by the superheater can be provided by the high-temperature flue gas generated by the gas treatment module.

[0087] One superheater is configured for two gas treatment modules. At this time, in this embodiment, one superheater corresponds to two gas treatment modules, and the superheater is used to heat the saturated steam obtained from the two gas treatment modules corresponding to the superheater to obtain superheated steam.

[0088] (III) Power generation module

[0089] The power generation module of this embodiment can adopt technologies such as the organic Rankine cycle low-temperature waste heat power generation technology, the screw expander power generation technology, or the steam turbine power generation technology, etc. When the number n1 of gas treatment modules built ≤ 3, the organic Rankine cycle low-temperature waste heat power generation technology or the screw expander power generation technology can be adopted. When the number n1 of gas treatment modules built ≥ 4, the steam turbine power generation technology can be adopted.

[0090] At this time, in this embodiment, when the configured number of gas treatment modules is less than or equal to 3, the power generation module adopts a power generation device based on the organic Rankine cycle low-temperature waste heat power generation or a power generation device based on the screw expander power generation; when the configured number of gas treatment modules is greater than or equal to 4, the power generation module adopts a power generation device based on the steam turbine power generation.

[0091] (IV) Flue gas purification module

[0092] The flue gas purification module is used to purify the low-temperature flue gas, remove harmful substances in the low-temperature flue gas, and obtain the flue gas that can be discharged, so that the flue gas that can be discharged meets the emission standards.

[0093] (V) Exhaust steam treatment module

[0094] The waste steam treatment module of this embodiment includes a condensation unit and a water treatment unit. The condensation unit is used to condense the waste steam into condensed water, and the water treatment unit is used to treat the condensed water, adjust the water quality of the condensed water, and remove impurities, pollutants or harmful substances in the water.

[0095] At this time, in this embodiment, the waste steam treatment module includes: a condensation unit and a water treatment unit. The condensation unit is used to perform condensation treatment on the waste steam to obtain condensed water, and the water treatment unit is used to treat the water quality of the condensed water to obtain low-temperature water and transport the low-temperature water to the gas treatment module, specifically to the waste heat boiler in the gas treatment module.

[0096] The flameless oxidation power generation system for low-concentration gas of this embodiment includes a gas pretreatment unit, a flameless oxidation device for gas, a waste heat boiler, a flue gas purification module, a superheater, a power generation module, a condensation unit and a water treatment unit, which can achieve energy conservation and emission reduction in coal mines. Its working process is as follows: The low-concentration gas is pretreated by the gas pretreatment unit. After meeting the intake requirements of the flameless oxidation device for gas, the pretreated gas enters the flameless oxidation device for gas for flameless oxidation to obtain high-temperature flue gas. The high-temperature flue gas generated after flameless oxidation enters the waste heat boiler and exchanges heat with the low-temperature water in the waste heat boiler. After the obtained low-temperature flue gas is purified by the flue gas purification module and reaches the emission standards of the corresponding region (i.e., the region where the flameless oxidation power generation system for low-concentration gas of this embodiment is located), the obtained flue gas that can be discharged is discharged. The low-temperature water in the waste heat boiler absorbs heat and vaporizes to generate saturated steam. The saturated steam enters the superheater and is further heated in the superheater to become superheated steam. The superheated steam that meets the power generation requirements is sent to the power generation module to generate electric energy. The waste steam obtained after the superheated steam does work is condensed by the condensation unit, and the obtained condensed water is sent to the water treatment unit. After being treated up to standard by the water treatment unit, the obtained low-temperature water is sent to the waste heat boiler for repeated circulation.

[0097] Among them, meeting the intake requirements of the flameless oxidation device for gas can be: intake volume > 5000 Nm 3 / h, concentration > 1%, moisture content ≤ 40 g / Nm 3 , impurity particle size ≤ 8 μm, impurity content ≤ 50 mg / Nm 3 , pressure is 3 - 20 kPa, pressure change rate ≤ 1 kPa / min.

[0098] The emission standards of the flue gas can be the emission standards of the corresponding region or the national standards. Generally, for ordinary regions: NOx ≤ 80 mg / m 3 , for key control regions: NOx ≤ 100 mg / m 3 , SO2 ≤ 50 mg / m 3 , particulate matter ≤ 10 mg / m 3 .

[0099] The water quality indicators and standards for the water treatment unit to meet the requirements are as follows: for medium-pressure boilers, hardness: the feed water hardness should not exceed 3 μmol / L; conductivity: the feed water conductivity should not exceed 5 μS / cm; phosphate content: the feed water phosphate content is generally controlled at 5-15 mg / L; silica content: the feed water silica content should not exceed 2 mg / L; pH value: the feed water pH value should be controlled between 8.5 and 9.5, and too high or too low will have an adverse impact on boiler equipment; dissolved oxygen concentration: the dissolved oxygen concentration is within a reasonable range to prevent corrosion of boiler equipment.

[0100] The core of this embodiment is modular design, skid-mounted combination and multi-module combination, that is, each module adopts a skid-mounted structure, which is easy to transport and install, convenient to arrange, and can be disassembled, assembled and transported at any time. Especially, it is suitable for areas with complex terrain and landforms, with low investment costs, and can make the gas treatment module match the gas intake volume through matching and dynamic control (setting the configuration quantity and operation quantity of the gas treatment module).

[0101] This embodiment is also provided with a control module. The control module collects the signals of each module, makes judgments according to the target requirements, and gives instructions to always keep the low-concentration gas flameless oxidation power generation system at a high efficiency. Specifically, the control module collects the concentration and intake volume of the pretreated gas generated by the gas pretreatment unit, the temperature and flow rate of the high-temperature flue gas generated by the gas flameless oxidation device, the temperature, pressure and flow rate of the saturated steam generated by the waste heat boiler, the temperature, pressure and flow rate of the superheated steam generated by the superheater, the flue gas indexes of the flue gas that can be discharged generated by the flue gas purification module (which can include the content of nitrogen oxides, sulfur oxides, carbon monoxide and carbon dioxide), the power generation amount of the electric energy generated by the power generation module and the temperature of the exhausted steam generated, and the water quality indexes of the low-temperature water generated by the water treatment unit. When operating with a superheater, taking the temperature, pressure and flow rate of the superheated steam generated by the superheater and the temperature, pressure and flow rate of the saturated steam generated by the waste heat boiler as the target parameters, the combustion condition is adjusted through the parameter change of the waste heat boiler. Specifically, if the temperature and pressure of the saturated steam or superheated steam are slightly higher than the rated parameters (that is, the difference is less than the preset value), the exhaust loss can be increased through the purge fan, thereby reducing the effective heat utilization amount. If the temperature and pressure of the saturated steam or superheated steam are significantly higher than the rated parameters (that is, the difference is greater than the preset value), the valve opening of the intake pipeline can be controlled to reduce the intake volume of the pretreated gas entering the gas flameless oxidation device, thereby reducing the thermal power of the gas flameless oxidation device. If the temperature and pressure of the saturated steam or superheated steam are lower than the rated parameters, the intake volume of the pretreated gas entering the gas flameless oxidation device is adjusted to increase the combustion power, that is, to increase the thermal power of the gas flameless oxidation device, so as to obtain qualified steam quality; the intake volume of the pretreated gas entering the gas flameless oxidation device is adjusted according to the temperature and flow rate of the high-temperature flue gas generated by the gas flameless oxidation device. When the temperature is low or the flow rate is small, the valve opening of the intake pipeline is increased to increase the intake volume of the pretreated gas entering the gas flameless oxidation device; when the temperature is high or the flow rate is large, the valve opening of the intake pipeline is reduced to reduce the intake volume of the pretreated gas entering the gas flameless oxidation device; the gas intake volume or the circulating water volume of the gas flameless oxidation device is finely adjusted according to the temperature, flow rate and pressure of the saturated steam generated by the waste heat boiler; according to the intake volume of the pretreated gas generated by the gas pretreatment unit, the temperature of the high-temperature flue gas generated by the gas flameless oxidation device, the temperature, pressure and flow rate of the saturated steam generated by the waste heat boiler and the temperature of the generated low-temperature flue gas, the power generation amount of the electric energy generated by the power generation module, and the flue gas indexes of the flue gas that can be discharged generated by the flue gas purification module, at 90m 3Taking the power generation of 200 kWh produced by gas (scalar) as the target parameter, relatively excellent operating conditions are screened out. Further, the self-power consumption under various operating conditions is compared, and the operating parameters used under the operating conditions of maximum power generation and minimum self-power consumption are taken as the economic operating parameters. The economic operating parameters include the intake volume of the pretreated gas produced by the gas pretreatment unit, the temperature of the high-temperature flue gas produced by the flameless oxidation device of the gas, the temperature, pressure and flow rate of the saturated steam produced by the waste heat boiler, and the temperature of the low-temperature flue gas produced. Among them, the temperature, pressure and flow rate of the saturated steam produced by the waste heat boiler are the indication parameters, and the remaining parameters are the input parameters for adjustment. During actual operation control, try to keep them consistent with the above parameters to shorten the combustion optimization adjustment cycle. At this time, the control module has a self-learning function and can give the best operating curve based on historical operating data to provide guidance for the actual operation of the low-concentration gas flameless oxidation power generation system.

[0102] This embodiment is a system for generating electricity using low-concentration gas produced during coal mine mining, which can fully realize the local and efficient utilization of low-concentration gas, solve the problems of local consumption of coal mine gas and coal mine heating in winter, and contribute to energy conservation and carbon reduction in coal production. Aiming at the problem of low power generation efficiency in traditional gas flameless oxidation power generation, in traditional gas flameless oxidation power generation, the gas concentration is blended to 1.2%, and a part of the heat will be carried away by the air, resulting in low thermal efficiency and thus low power generation efficiency. This embodiment directly uses low-concentration gas without blending, so the power generation efficiency can be improved. Aiming at the problem of concentration fluctuation in traditional gas flameless oxidation power generation, traditional gas flameless oxidation power generation requires a basically stable methane concentration. In actual operation, the methane concentration in the gas fluctuates too much, which is likely to cause protection shutdown or a serious decline in power generation efficiency. Moreover, the gas concentration extracted from the underground is unstable, which will cause the gas concentration entering the gas flameless oxidation device to fluctuate, affecting the stability of the oxidation reaction and the power generation efficiency. In this embodiment, by setting the configuration quantity and operation quantity of the gas treatment module and setting a gas pretreatment unit, a basically stable methane concentration and gas concentration can be provided for the gas flameless oxidation device, so the problem of concentration fluctuation can be solved.

[0103] Embodiment 2

[0104] This embodiment provides a skid-mounted low-concentration gas flameless oxidation power generation method, which works based on the skid-mounted low-concentration gas flameless oxidation power generation system described in Embodiment 1, as Figure 2 shown, including:

[0105] S1: The gas treatment module conducts flameless oxidation on the low-concentration gas to obtain high-temperature flue gas, and exchanges heat between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam; the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature water, and the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature flue gas.

[0106] S2: The superheater heats the saturated steam to obtain superheated steam.

[0107] S3: The power generation module generates electricity based on the superheated steam to obtain exhaust steam and electric energy.

[0108] S4: The flue gas purification module purifies the low-temperature flue gas to obtain flue gas that can be discharged.

[0109] S5: The exhaust steam treatment module treats the exhaust steam to obtain low-temperature water and transports the low-temperature water to the gas treatment module.

[0110] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0111] In this article, specific examples are used to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A skid-mounted flameless oxidation power generation system for low-concentration gas, characterized in that, Including: A gas treatment module, a superheater, a power generation module, a flue gas purification module, and a waste steam treatment module. The gas treatment module, the superheater, the power generation module, the flue gas purification module, and the waste steam treatment module all adopt a skid-mounted structure; The gas treatment module is used for flameless oxidation of low-concentration gas to obtain high-temperature flue gas, and heat exchange the high-temperature flue gas with low-temperature water to obtain low-temperature flue gas and saturated steam; the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature water, and the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature flue gas; The superheater is used for heating the saturated steam to obtain superheated steam; The power generation module is used for generating electricity based on the superheated steam to obtain waste steam and electric energy; The flue gas purification module is used for purifying the low-temperature flue gas to obtain flue gas that can be discharged; The waste steam treatment module is used for treating the waste steam to obtain low-temperature water, and conveying the low-temperature water to the gas treatment module.

2. The skid-mounted low-concentration gas flameless oxidation power generation system according to claim 1, characterized in that, The configured quantity of the gas treatment module is determined based on the intake volume and concentration of low-concentration gas. Where n1 is the configured quantity of the gas treatment module. is rounding up, V is the intake volume of low-concentration gas, and C is the concentration of low-concentration gas. The number of operating gas treatment modules is determined based on the intake volume and concentration of low-concentration gas. where n2 is the number of operating gas treatment modules; One superheater corresponds to two gas treatment modules. The superheater is used for heating the saturated steam obtained by the two gas treatment modules corresponding to the superheater to obtain superheated steam.

3. The skid-mounted flameless oxidation power generation system for low-concentration gas according to claim 1, characterized in that, The gas treatment module includes: a gas pretreatment unit, a flameless oxidation device for gas, and a waste heat boiler; The gas pretreatment unit is used for pre-treating low-concentration gas to obtain pre-treated gas; The flameless oxidation device for gas is used for flameless oxidation of the pre-treated gas to obtain high-temperature flue gas; The waste heat boiler is used for heat exchange between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam, and receive the low-temperature water conveyed by the waste steam treatment module.

4. The skid-mounted flameless oxidation power generation system for low-concentration gas according to claim 3, wherein, The gas pretreatment unit includes: a redundant safety control sub-unit, a multi-stage dehydration sub-unit, and a dynamic pressure boosting and regulating sub-unit connected in sequence; The redundant safety control sub-unit includes: a first controller, a methane concentration sensor, and a pneumatic cut-off valve. The methane concentration sensor is installed at the air inlet of the multi-stage dehydration sub-unit, and the pneumatic cut-off valve is installed on the air inlet pipeline of the multi-stage dehydration sub-unit; the methane concentration sensor is used for detecting the methane concentration in the low-concentration gas, and the first controller is used for controlling the pneumatic cut-off valve to close to prohibit the low-concentration gas from entering the multi-stage dehydration sub-unit when the duration of the methane concentration being greater than the methane concentration upper limit is greater than the duration upper limit; The multi-stage dehydration sub-unit includes: a rough dehydration device, a fine dehydration device, and a self-cleaning filter connected in sequence; The dynamic supercharging regulation subunit includes: a second controller, a two-channel Roots supercharger, a pressure sensor, and an anti-surge reflux valve. The pressure sensor is installed at the air outlet of the two-channel Roots supercharger, and the anti-surge reflux valve is installed on the connecting pipeline. The connecting pipeline is a pipeline for connecting the air inlet and the air outlet of the two-channel Roots supercharger. The pressure sensor is used to detect the pressure of the air at the air outlet. The second controller is used to control the rotational speed of the two-channel Roots supercharger and the opening and closing of the anti-surge reflux valve based on the pressure. After the anti-surge reflux valve is opened, part of the air at the air outlet of the two-channel Roots supercharger flows back to the air inlet of the two-channel Roots supercharger.

5. The skid-mounted flameless oxidation power generation system for low-concentration gas according to claim 4, characterized in that, The methane concentration sensor includes: a laser methane sensor, an infrared sensor, and a catalytic combustion sensor; The laser methane sensor is used to detect the methane concentration in low-concentration gas and obtain a first methane concentration; The infrared sensor is used to detect the methane concentration in low-concentration gas and obtain a second methane concentration; The catalytic combustion sensor is used to detect the methane concentration in low-concentration gas and obtain a third methane concentration; The first controller is used to judge whether the absolute value of the difference between the first methane concentration and the third methane concentration is less than a preset difference, and obtain a first judgment result. If the first judgment result is yes, the first methane concentration is used as the methane concentration detected by the methane concentration sensor. If the first judgment result is no, it is judged whether the absolute value of the difference between the second methane concentration and the third methane concentration is less than the preset difference, and a second judgment result is obtained. If the second judgment result is yes, the second methane concentration is used as the methane concentration detected by the methane concentration sensor.

6. The skid-mounted low-concentration gas flameless oxidation power generation system according to claim 3, characterized in that, The flameless oxidation device for gas includes: a third controller, an oxidation chamber, an outer thermal insulation layer, and an auxiliary heating component; The outer thermal insulation layer wraps the oxidation chamber, and molten salt is filled between the outer thermal insulation layer and the oxidation chamber; The third controller is used to control the auxiliary heating component to turn on and raise the temperature of the oxidation chamber to a preset temperature when the concentration of the pretreated gas is less than the preset concentration. Among them, the auxiliary heating component uses fuel-assisted heating or electric-assisted heating.

7. The skid-mounted flameless oxidation power generation system for low-concentration gas according to claim 3, characterized in that, The heating surface in the flue gas inlet section of the waste heat boiler uses plain tubes, and the heating surface in the flue gas outlet section of the waste heat boiler uses corrugated tubes or finned tubes.

8. The skid-mounted flameless oxidation power generation system for low-concentration gas according to claim 2, wherein When the configured quantity of the gas treatment module is less than or equal to 3, the power generation module uses a power generation device based on low-temperature waste heat power generation of the organic Rankine cycle or a power generation device based on screw expander power generation; when the configured quantity of the gas treatment module is greater than or equal to 4, the power generation module uses a power generation device based on steam turbine power generation.

9. The skid-mounted flameless oxidation power generation system for low-concentration gas according to claim 1, wherein, The exhaust steam treatment module includes: a condensation unit and a water treatment unit; The condensation unit is used to condense the exhaust steam to obtain condensed water; The water treatment unit is used to treat the water quality of the condensed water to obtain low-temperature water and transport the low-temperature water to the gas treatment module.

10. A skid-mounted flameless oxidation power generation method for low-concentration gas, which works based on the skid-mounted flameless oxidation power generation system described in any one of claims 1-9, is characterized in that, Includes: The gas treatment module conducts flameless oxidation on low-concentration gas to obtain high-temperature flue gas, and exchanges heat between the high-temperature flue gas and low-temperature water to obtain low-temperature flue gas and saturated steam; the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature water, and the temperature of the high-temperature flue gas is greater than the temperature of the low-temperature flue gas; The superheater heats the saturated steam to obtain superheated steam; The power generation module generates electricity based on the superheated steam to obtain exhausted steam and electric energy; The flue gas purification module purifies the low-temperature flue gas to obtain flue gas that can be discharged; The exhausted steam treatment module treats the exhausted steam to obtain low-temperature water, and conveys the low-temperature water to the gas treatment module.

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