Methane flow temperature swing heat pump enrichment system and method

Abstract

The present application provides a kind of methane flow temperature swing heat recovery enrichment system and method, including adsorption module, gas path control module;The adsorption module includes first adsorption cavity, second adsorption cavity and third adsorption cavity connected by gas path;Gas path control module is used to control gas path to realize: when cold raw material gas enters first adsorption cavity and carries out methane adsorption, hot blow gas carries out methane desorption in second adsorption cavity and third adsorption cavity in turn;When cold raw material gas enters second adsorption cavity and carries out methane adsorption, hot blow gas carries out methane desorption in third adsorption cavity and first adsorption cavity in turn;When cold raw material gas enters third adsorption cavity and carries out methane adsorption, hot blow gas carries out methane desorption in first adsorption cavity and second adsorption cavity in turn.The present application omits the pressurization and vacuumizing equipment of pressure swing adsorption or low-temperature refrigeration low-temperature equipment, reduces early equipment capital investment, utilizes stage heat recovery, improves energy utilization rate.

Description

Technical Field

[0001] This invention relates to methane gas separation technology, specifically to a methane flow temperature-controlled regenerative enrichment system and method. Background Technology

[0002] Existing methane gas separation technologies mainly include pressure swing adsorption (PSA) enrichment and cryogenic liquefaction separation. Compared with the traditional high-concentration methane separation method, cryogenic liquefaction, while adsorption methods are difficult to purify methane to extremely high purity, have significant advantages in terms of initial equipment investment, operating costs, and operational safety. Traditional PSA has the advantages of high concentration ratio and relatively simple equipment, but it is still limited by pressure changes and adsorbent strength issues, making it difficult to reduce the pressure resistance and sealing performance of the adsorption chamber, as well as the initial investment costs of compressors and vacuum pumps.

[0003] The most energy-efficient enrichment method currently recognized is temperature-coupled pressure swing adsorption (PTSA), which achieves low energy consumption. However, the enrichment control methods are strict and require multi-stage control of pressurization and heating, making the enrichment process complex and the initial investment in equipment high.

[0004] like Figure 1 As shown, in existing multi-stage series variable temperature enrichment systems, each adsorption chamber can be considered a stage, and the inlet gas for all stages is coal mine gas. However, the hot stripping gas for each stage is composed of the hot stripping gas from the previous stage. Therefore, the amount of methane desorbed can be kept basically consistent with each stripping, enabling rapid enrichment of low-concentration methane gas. In the above-mentioned basic enrichment system, each stage is equipped with independent heating and cooling devices. Continuous flow adsorption is achieved through the reasonable arrangement of adsorption and desorption chambers. This system is relatively simple and easy to install, but its energy utilization rate is low, and the energy in the hot stripping gas is not fully utilized. Summary of the Invention

[0005] To address the problems of the prior art, this invention provides a methane flow temperature-switching regenerative enrichment system and method, which eliminates the need for pressurization and vacuuming equipment in pressure swing adsorption or cryogenic equipment in cryogenic refrigeration, reducing upfront equipment investment and improving energy utilization by utilizing in-stage regeneration.

[0006] This invention is achieved through the following technical solution:

[0007] A methane flow temperature-varying regenerative enrichment system includes an adsorption module and a gas path control module; the adsorption module includes a first adsorption chamber, a second adsorption chamber, and a third adsorption chamber connected by a gas path;

[0008] The gas path control module is used to control the opening and closing of the gas path to realize: when the cold raw material gas enters the first adsorption cavity for methane adsorption, the hot blow gas sequentially passes through the second adsorption cavity and the third adsorption cavity for methane desorption; when the cold raw material gas enters the second adsorption cavity for methane adsorption, the hot blow gas sequentially passes through the third adsorption cavity and the first adsorption cavity for methane desorption; when the cold raw material gas enters the third adsorption cavity for methane adsorption, the hot blow gas sequentially passes through the first adsorption cavity and the second adsorption cavity for methane desorption.

[0009] Preferably, the gas path control module is a valve assembly.

[0010] Further, the valve assembly comprises a first four-way valve, a first three-way valve, a second three-way valve, a second four-way valve, a third three-way valve, a fourth three-way valve, a third four-way valve, a fifth three-way valve, a fourth four-way valve, a first waste heat valve, a second waste heat valve and a third waste heat valve.

[0011] The raw material gas inlet is connected with the first adsorption cavity inlet through the first four-way valve, the first three-way valve and the second three-way valve in sequence, the raw material gas inlet is connected with the second adsorption cavity inlet through the first four-way valve, and the raw material gas inlet is connected with the third adsorption cavity inlet through the first four-way valve and the third three-way valve; the hot blow gas inlet is connected with the first adsorption cavity inlet through the second four-way valve, the first three-way valve and the second three-way valve in sequence, the hot blow gas inlet is connected with the second adsorption cavity inlet through the second four-way valve in sequence, and the hot blow gas inlet is connected with the third adsorption cavity inlet through the second four-way valve and the third three-way valve in sequence; the first adsorption cavity outlet is connected with the nitrogen gas outlet through the fourth three-way valve and the third four-way valve in sequence, and the first adsorption cavity outlet is connected with the methane enrichment outlet through the fourth three-way valve and the fourth four-way valve in sequence; the second adsorption cavity outlet is connected with the nitrogen gas outlet through the third four-way valve, and the second adsorption cavity outlet is connected with the methane enrichment outlet through the fourth four-way valve; the third adsorption cavity outlet is connected with the nitrogen gas outlet through the fifth three-way valve and the third four-way valve in sequence, and the third adsorption cavity outlet is connected with the methane enrichment outlet through the fifth three-way valve and the fourth four-way valve in sequence; the first adsorption cavity outlet is connected with the second adsorption cavity inlet through the first waste heat valve, the second adsorption cavity outlet is connected with the third adsorption cavity inlet through the second waste heat valve in sequence, and the third adsorption cavity outlet is connected with the first adsorption cavity inlet through the third waste heat valve and the second three-way valve in sequence.

[0012] Preferably, the preheating module is further provided, and the preheating module is used to preheat the gas to obtain the hot blow gas.

[0013] Further, the heat source of the preheating module is geothermal energy, solar energy or a phase change heat storage device.

[0014] Preferably, the parameter measurement module further comprises a flow measurement module, a methane concentration measurement module and a temperature measurement module; the flow measurement module is used for measuring the gas flow at the outlet of each adsorption cavity; the methane concentration measurement module is used for measuring the methane concentration at the outlet of each adsorption cavity; and the temperature measurement module is used for measuring the gas temperature inside each adsorption cavity and the temperature of the hot blow gas.

[0015] Preferably, the adsorbent used in the adsorption module is biomass activated carbon.

[0016] Preferably, the biomass activated carbon is obtained by carbonizing walnut shells.

[0017] A methane flow variable-temperature heat recovery enrichment method, based on the system, when the first adsorption cavity is in a cold-blow adsorption stage, the third adsorption cavity is in a low-temperature hot-blow desorption stage, and the second adsorption cavity is in a high-temperature hot-blow desorption stage, cold raw gas enters the first adsorption cavity for methane adsorption, and hot blow gas sequentially passes through the second adsorption cavity and the third adsorption cavity for methane desorption; when the low-temperature adsorbent in the third adsorption cavity rises to a preset switching temperature, cold raw gas enters the second adsorption cavity for methane adsorption, and hot blow gas sequentially passes through the third adsorption cavity and the first adsorption cavity for methane desorption; when the low-temperature adsorbent in the first adsorption cavity rises to a preset switching temperature, cold raw gas enters the third adsorption cavity for methane adsorption, and hot blow gas sequentially passes through the first adsorption cavity and the second adsorption cavity for methane desorption, thus, a cycle period ends, and the above process is repeated.

[0018] Preferably, the preset switching temperature is 0.7-0.9 times the initial temperature of the hot exhaust gas.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The methane flow variable-temperature heat recovery enrichment system of the present application, when cold raw gas enters the first adsorption cavity for methane adsorption, hot blow gas sequentially passes through the second adsorption cavity and the third adsorption cavity for methane desorption, that is, at this time, the second adsorption cavity and the third adsorption cavity are connected in series, the heat absorbed by the hot blow gas in the second adsorption cavity is transferred to the third adsorption cavity, the effective energy loss caused by the non-uniform exhaust gas temperature of the originally intermittent single-cavity operation is self-reused in the stage, the exhaust gas temperature fluctuation is reduced, and energy saving is realized in the structural principle. The present application discards pressure swing adsorption and uses temperature swing adsorption for methane enrichment, realizes in-stage heat recovery through improvement, improves energy utilization rate, eliminates the need for pressurization and vacuumization equipment or low-temperature equipment for low-temperature refrigeration in pressure swing adsorption, reduces the initial equipment investment, and solves the problems of large energy consumption, high cost, discontinuity, poor adaptability and the like in the existing pressure swing adsorption, temperature swing adsorption and liquefied separation adsorption technologies.

[0021] Further, the application occasion combined with methane gas separation is coal mine and the abundant geothermal resources in the coal mine underground, and the geothermal resources are used as a heating source to preheat the gas to become hot blowing gas for temperature swing adsorption, and change harm into benefit.

[0022] Further, the commonly used adsorbent at present is coconut shell activated carbon, and the source of the coconut shell is mainly imported at present stage in China, and the cost is higher. The application relies on the regional advantage, fully utilizes the secondary product walnut shell of the agricultural specialty walnut in Shaanxi Province to prepare and reuse the activated carbon adsorbent, and breaks away from the dependence on the coal-based activated carbon and the coconut shell activated carbon, and truly realizes the local conditions. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of the existing multistage series connection temperature swing enrichment system;

[0024] Figure 2 It is a schematic diagram of the methane flow temperature swing regenerative enrichment system.

[0025] Wherein: the first adsorption cavity 1, the second adsorption cavity 2, the third adsorption cavity 3, the first four-way valve 6, the first three-way valve 7, the second three-way valve 8, the second four-way valve 5, the third three-way valve 4, the fourth three-way valve 9, the third four-way valve 10, the fifth three-way valve 11, the fourth four-way valve 12, the first waste heat valve 13, the second waste heat valve 14 and the third waste heat valve 15. DETAILED DESCRIPTION

[0026] In order to further understand the application, the application is described below in combination with examples, and these descriptions are only used to further explain the features and advantages of the application, and are not used to limit the claims of the application.

[0027] As shown in the methane flow temperature swing regenerative enrichment system, the methane flow temperature swing regenerative enrichment system comprises an adsorption module, a gas path control module, a parameter measurement module and a preheating module. Figure 2 The gas path control module is used to control the on-off of the gas path to realize that when the cold raw material gas enters the first adsorption cavity 1 to perform methane adsorption, the hot blowing gas sequentially performs methane desorption through the second adsorption cavity 2 and the third adsorption cavity 3; when the cold raw material gas enters the second adsorption cavity 2 to perform methane adsorption, the hot blowing gas sequentially performs methane desorption through the third adsorption cavity 3 and the first adsorption cavity 1; and when the cold raw material gas enters the third adsorption cavity 3 to perform methane adsorption, the hot blowing gas sequentially performs methane desorption through the first adsorption cavity 1 and the second adsorption cavity 2. The cold raw material gas is the gas of the coal mine.

[0028]

[0029] ​The gas path control module comprises a first four-way valve 6, a first three-way valve 7, a second three-way valve 8, a second four-way valve 5, a third three-way valve 4, a fourth three-way valve 9, a third four-way valve 10, a fifth three-way valve 11, a fourth four-way valve 12, a first waste heat valve 13, a second waste heat valve 14, and a third waste heat valve 15.

[0030] The raw gas inlet is connected with the inlet of the first adsorption cavity 1 through the first four-way valve 6, the first three-way valve 7, and the second three-way valve 8, connected with the inlet of the second adsorption cavity 2 through the first four-way valve 6, and connected with the inlet of the third adsorption cavity 3 through the first four-way valve 6 and the third three-way valve 4; the hot blow gas inlet is connected with the inlet of the first adsorption cavity 1 through the second four-way valve 5, the first three-way valve 7, and the second three-way valve 8, connected with the inlet of the second adsorption cavity 2 through the second four-way valve 5, and connected with the inlet of the third adsorption cavity 3 through the second four-way valve 5 and the third three-way valve 4; the outlet of the first adsorption cavity 1 is connected with the nitrogen gas outlet through the fourth three-way valve 9 and the third four-way valve 10, and connected with the methane enrichment outlet through the fourth three-way valve 9 and the fourth four-way valve 12; the outlet of the second adsorption cavity 2 is connected with the nitrogen gas outlet through the third four-way valve 10, and connected with the methane enrichment outlet through the fourth four-way valve 12; the outlet of the third adsorption cavity 3 is connected with the nitrogen gas outlet through the fifth three-way valve 11, the third four-way valve 10, and connected with the methane enrichment outlet through the fifth three-way valve 11 and the fourth four-way valve 12; the outlet of the first adsorption cavity 1 is connected with the inlet of the second adsorption cavity 2 through the first waste heat valve 13; the outlet of the second adsorption cavity 2 is connected with the inlet of the third adsorption cavity 3 through the second waste heat valve 14; and the outlet of the third adsorption cavity 3 is connected with the inlet of the first adsorption cavity 1 through the third waste heat valve 15 and the second three-way valve 8. The single-stage methane flow swing adsorption system is designed according to experimental principles and meets the experimental conditions of flow adsorption and slow adsorption modeling.

[0031] The adsorption cavity of the embodiment of the present application adopts an RBZ-02 type water path protector, the inlet pressure is 0.1-0.8 MPa, the adsorption cavity adopts a double-layer cylindrical nested design, the cavity material is 304 stainless steel, the internal cylindrical cavity has a diameter of 5.0 cm and a height of 20 cm, and can hold 250 g of activated carbon at most, and can be used for cold blow adsorption and hot blow desorption. The adsorption cavity is filled with adsorbents (self-made biomass activated carbon or industrial adsorption activated carbon).

[0032] The gas path control module of the embodiment of the present application uses a rotor flow meter to control the flow of mixed gas, and the control end is located at the nitrogen gas outlet and the methane enrichment outlet; the methane rotor flow meter has a range of 16-60 mL / min and an accuracy of 4 mL / min, and the nitrogen gas rotor flow meter has a range of 0.3-3 L / min and an accuracy of 0.1 L / min. A series of three-way valves and four-way valves are used to control the gas flow in the system.

[0033] The parameter measurement module of the embodiment of the present application comprises a methane concentration measurement module and a temperature measurement module; a mine special pump suction type concentration detector (range 0-50000 PPM, accuracy 1 PPM) is used for measuring the methane concentration at the outlet gas, the measurement point is located at the downstream of the adsorption cavity and at the outlet of the gas path; the temperature measurement module is used for measuring the gas temperature in the adsorption cavity and the heating temperature, the K-type thermocouple (probe diameter 5 mm, rod length 20 mm) is used as the temperature measuring element, the gas temperature measurement point in the adsorption cavity is located at the pressure measurement reserved hole at the upper end of the adsorption cavity cover and extends to the inside of the cavity, the heating temperature measurement point is located in the methyl silicone oil for oil bath, and the two-way temperature signals are displayed through the matching digital display table (DT1320 type, range 200-300 DEG C, accuracy 0.1 DEG C).

[0034] The above parameter measurement can be used for real-time display and monitoring, and can also be used for subsequent access to integrated circuits for automatic control. The structure of the rotor flowmeter is to measure the flow while having an adjusting knob, which simultaneously plays the roles of measuring the flow and adjusting the flow. The methane concentration measurement module measures the concentration, and the purpose is to determine the methane concentration entering the adsorption cavity and the gas methane concentration desorbed, which is a key parameter for measuring the concentration effect; and the temperature measurement mainly monitors the temperature rise of the adsorbent activated carbon, which needs to be controlled at a certain temperature, and if the temperature is too high, the irreversible damage of the adsorption performance of the activated carbon will be caused.

[0035] The preheating module of the embodiment of the present application is composed of an electromagnetic oven (rated power 2200 W) and high phenyl methyl silicone oil (upper limit of temperature resistance 300 DEG C) for oil bath, after the adsorption stage is completed, the temperature needs to be set and the nitrogen is preheated to simulate the actual temperature rise of the mixed gas, after the preheating, the hot blow gas flows into the adsorption cavity through the pipeline wrapped by the heat preservation material (glass wool heat preservation pipeline and heat preservation pad) to perform the hot blow desorption, and the methane mixed gas higher than the inlet concentration is obtained.

[0036] The adsorption cavity of the application needs additional heating, and the adsorption cavity is wrapped with heat preservation material outside to protect the heat of the hot air and prevent the heat from being lost to the environment. The three adsorption cavities of the application have three heat recovery valves because the maximum heating temperature and the minimum cooling temperature of the three adsorption cavities are the same, but their sequences are staggered. For example, when the second adsorption cavity 2 is heated by the hot air to the maximum temperature, the third adsorption cavity 3 is heated by the hot air to a lower temperature, and the first adsorption cavity 1 is in the cold air, the tail gas of the second adsorption cavity 2 can enter the third adsorption cavity 3 for waste heat recovery. When the third adsorption cavity 3 reaches a higher temperature, the first adsorption cavity 1 completes cold air adsorption, and the second adsorption cavity 2 completes hot air desorption, then the second waste heat valve can be closed, and the third waste heat valve takes the responsibility of introducing the tail gas of the third adsorption cavity 3 into the first adsorption cavity 1, and the first waste heat valve, the second waste heat valve and the third waste heat valve are opened in turn to form an alternating working state similar to the different cars of a Ferris wheel reaching the highest point in turn.

[0037] The adsorption cavity of the application is preferably filled with biomass activated carbon, and the preparation scheme of the biomass activated carbon mainly includes carbonization treatment of walnut shell, a biomass peculiar to Shaanxi, and mainly includes processes such as grinding, chemical treatment, high-temperature carbonization and acid pickling.

[0038] The preparation process of the biomass activated carbon in the embodiment of the application includes:

[0039] (1) Physical grinding process

[0040] On the test bench, first, a certain amount of walnut shell is weighed by a beaker and an electronic scale; the walnut shell is ground in a mortar for 5-10 min, and the fineness is maintained to be the same as that of oatmeal; the walnut shell with relatively coarse particles is sieved out by using a 200-mesh net bag, and the remaining powder is reserved; the coarse walnut shell particles are placed in an evaporating dish, the muffle furnace is set to 105 DEG C, the high-temperature air is dried for 30 min in an air-tight manner, and then the evaporating dish is naturally cooled and bottled for use.

[0041] (2) Chemical and heat treatment preparation process

[0042] KOH is dissolved in a beaker according to a certain mass fraction (50%), and the ground walnut shell particles are added to the beaker, which is placed in a muffle furnace at 60 DEG C for 3 h for soaking, and then the temperature is increased to 150 DEG C to evaporate the water (1 h), and the mixture is naturally cooled; the dried mixture is placed in a porcelain boat and placed in a tube furnace, and carbonization and activation are carried out under a nitrogen flow of 100 ml / min, and the temperature is programmed to increase to 850 DEG C, and the temperature is maintained for 1 h, and then the temperature is naturally cooled to room temperature, and the mixture is bottled for use.

[0043] After carbonization, hydrochloric acid pickling and drying filtration are carried out, the sample is bottled for standby, and iodine adsorption value determination is carried out, and the iodine adsorption value determination of the wood active carbon test method in the national standard GB / T 12496.8-2015 is referred to.

[0044] The active carbon adsorbent can be used not only for adsorption separation of methane gas, but also for removal of harmful impurities in LNG tail gas, air separation, carbon dioxide capture and other gas separation fields, and the active carbon adsorbent can be replaced by a zeolite molecular sieve.

[0045] The working process of the methane flow temperature swing heat recovery enrichment system is as follows: when the first adsorption cavity 1 is in the cold-blow adsorption stage, the third adsorption cavity 3 is in the low-temperature heat-blow desorption stage, and the second adsorption cavity 2 is in the high-temperature heat-blow desorption stage, cold raw material gas enters the first adsorption cavity 1 to adsorb methane, and hot blow gas sequentially passes through the second adsorption cavity 2 and the third adsorption cavity 3 to desorb methane; when the high-temperature adsorbent in the second adsorption cavity 2 is completely desorbed, the low-temperature adsorbent in the third adsorption cavity 3 is raised to high temperature, and the adsorbent in the first adsorption cavity 1 is completely adsorbed, cold raw material gas enters the second adsorption cavity 2 to adsorb methane, and hot blow gas sequentially passes through the third adsorption cavity 3 and the first adsorption cavity 1 to desorb methane; when the high-temperature adsorbent in the third adsorption cavity 3 is completely desorbed, the low-temperature adsorbent in the first adsorption cavity 1 is raised to high temperature, and the adsorbent in the second adsorption cavity 2 is completely adsorbed, cold raw material gas enters the third adsorption cavity 3 to adsorb methane, and hot blow gas sequentially passes through the first adsorption cavity 1 and the second adsorption cavity 2 to desorb methane.

[0046] Specifically: when the first adsorption cavity 1 is in the cold-blow adsorption stage, the third adsorption cavity 3 is in the low-temperature heat-blow desorption stage, and the second adsorption cavity 2 is in the high-temperature heat-blow desorption stage, the second waste heat valve 14 is opened, the first waste heat valve 13 and the third waste heat valve 15 are closed, so that the second adsorption cavity 2 and the third adsorption cavity 3 are in a series connection state, cold raw material gas enters the first adsorption cavity 1 from the raw material gas inlet through the first four-way valve 6, the first three-way valve 7 and the second three-way valve 8, is adsorbed by the adsorbent in the first adsorption cavity 1 and is discharged from the nitrogen gas outlet through the fourth three-way valve 9 and the third four-way valve 10, hot blow gas enters from the hot blow inlet, enters the second adsorption cavity 2 through the second four-way valve 5, is desorbed by the high-temperature adsorbent in the second adsorption cavity 2, then continues to enter the third adsorption cavity 3 through the second waste heat valve 14 to desorb the low-temperature adsorbent 3, and is then discharged from the methane enrichment outlet through the fifth three-way valve 11 and the fourth four-way valve 12, after a period of time, when the high-temperature adsorbent in the second adsorption cavity 2 is completely desorbed and the low-temperature adsorbent in the third adsorption cavity 3 is raised to high temperature (reaches the preset switching temperature t sAfter the adsorbent in the first adsorption chamber 1 has finished adsorbing, the second waste heat valve 14 and the first waste heat valve 13 are closed, and the third waste heat valve 15 is opened. Cold raw material gas enters the second adsorption chamber 2 through the raw material gas inlet and the first four-way valve 6. After being adsorbed by the adsorbent, it is discharged from the nitrogen outlet through the third four-way valve 10. Hot blowing gas enters from the hot blowing inlet, passes through the second four-way valve 5 and the third three-way valve 4, and enters the third adsorption chamber 3. After being desorbed by the high-temperature adsorbent, it continues to enter the first adsorption chamber 1 through the third waste heat valve 15 and the second three-way valve 8. After being desorbed by the low-temperature adsorbent, it is discharged from the methane enrichment outlet through the fourth three-way valve 9 and the fourth four-way valve 12. After a period of time, when the high-temperature adsorbent in the third adsorption chamber 3 has completely desorbed, the low-temperature adsorbent in the first adsorption chamber 1 rises to a high temperature (reaching the preset switching temperature t). s After the adsorbent in the second adsorption chamber 2 has finished adsorbing, the second waste heat valve 14 and the third waste heat valve 15 are closed, and the first waste heat valve 13 is opened. Cold raw material gas enters the third adsorption chamber 3 through the raw material gas inlet, the first four-way valve 6, and the third three-way valve 4. After adsorption by the adsorbent, it is discharged from the nitrogen outlet through the fifth three-way valve 11 and the third four-way valve 10. Hot blowing gas enters from the hot blowing inlet, passes through the second four-way valve 5, the first three-way valve 7, and the second three-way valve 8, and enters the first adsorption chamber 1. After high-temperature adsorbent desorption, it continues to enter the second adsorption chamber 2 through the first waste heat valve 13 for low-temperature adsorbent desorption, and then is discharged from the methane enrichment outlet through the fourth four-way valve 12. This completes one cycle of this stage, and the above process begins to repeat. The above process represents a complete operation of a single-stage regenerative cycle of this system. By designing the integrated three-chamber structure and adjusting the pipeline, energy utilization can be maximized, improving energy efficiency compared to a basic adsorption system.

[0047] This invention assigns a corresponding waste heat valve switching temperature t to different hot blowing gas temperatures. s After experimental verification, its empirical value is approximately 0.8 times the hot blowing gas temperature. This temperature means that when the high-temperature outlet gas temperature of a certain adsorption chamber reaches this temperature, the waste heat valve connected to it will open; otherwise, it will remain closed. For example, when the gas temperature at the outlet of the third adsorption chamber 3 reaches the preset switching temperature t... s At that time, the third waste heat valve 15 opens, and the other two waste heat valves close.

[0048] This technical solution can adsorb and collect methane gas directly emitted in coal mine production. The adsorption length L is calculated by using a slow flow model, and the cross-sectional area parameters of the adsorption chamber are obtained by combining relevant actual flow rates, thereby determining the overall parameters of the adsorption chamber.

Claims

1. A methane flow temperature-controlled regenerative enrichment system, characterized in that, It includes an adsorption module and a gas path control module; the adsorption module includes a first adsorption chamber (1), a second adsorption chamber (2) and a third adsorption chamber (3) connected by a gas path; The gas path control module is used to control the gas path opening and closing to achieve the following: when the first adsorption chamber (1) is in the cold blowing adsorption section, the third adsorption chamber (3) is in the low temperature hot blowing desorption section, and the second adsorption chamber (2) is in the high temperature hot blowing desorption section, the cold raw material gas enters the first adsorption chamber (1) for methane adsorption, and the hot blowing gas passes through the second adsorption chamber (2) and the third adsorption chamber (3) in sequence for methane desorption; when the low temperature adsorbent in the third adsorption chamber (3) rises to the preset switching temperature, the cold raw material gas enters the second adsorption chamber (2) for methane adsorption, and the hot blowing gas passes through the third adsorption chamber (3) and the first adsorption chamber (1) in sequence for methane desorption; when the low temperature adsorbent in the first adsorption chamber (1) rises to the preset switching temperature, the cold raw material gas enters the third adsorption chamber (3) for methane adsorption, and the hot blowing gas passes through the first adsorption chamber (1) and the second adsorption chamber (2) in sequence for methane desorption.

2. The methane flow temperature-controlled regenerative enrichment system according to claim 1, characterized in that, The pneumatic control module is a valve assembly.

3. The methane flow temperature-controlled regenerative enrichment system according to claim 2, characterized in that, The valve assembly includes a first four-way valve (6), a first three-way valve (7), a second three-way valve (8), a second four-way valve (5), a third three-way valve (4), a fourth three-way valve (9), a third four-way valve (10), a fifth three-way valve (11), a fourth four-way valve (12), a first waste heat valve (13), a second waste heat valve (14), and a third waste heat valve (15). The raw material gas inlet is connected to the inlet of the first adsorption chamber (1) via the first four-way valve (6), the first three-way valve (7), and the second three-way valve (8) in sequence. The raw material gas inlet is connected to the inlet of the second adsorption chamber (2) via the first four-way valve (6). The raw material gas inlet is connected to the inlet of the third adsorption chamber (3) via the first four-way valve (6) and the third three-way valve (4). The hot blowing gas inlet is connected to the inlet of the first adsorption chamber (1) via the second four-way valve (5), the first three-way valve (7), and the second three-way valve (8) in sequence. The inlet of the first adsorption chamber (1) is connected to the inlet of the second adsorption chamber (2) via the second four-way valve (5) and the inlet of the third adsorption chamber (3) via the second four-way valve (5) and the third three-way valve (4) respectively. The outlet of the first adsorption chamber (1) is connected to the nitrogen outlet via the fourth three-way valve (9) and the third four-way valve (10) respectively. The outlet of the first adsorption chamber (1) is connected to the methane enrichment outlet via the fourth three-way valve (9) and the fourth four-way valve (12) respectively. The outlet of the second adsorption chamber (2) is connected to the nitrogen outlet via the third four-way valve (10), and the outlet of the second adsorption chamber (2) is connected to the methane enrichment outlet via the fourth four-way valve (12). The outlet of the third adsorption chamber (3) is connected to the nitrogen outlet via the fifth three-way valve (11) and the third four-way valve (10) in sequence, and the outlet of the third adsorption chamber (3) is connected to the methane enrichment outlet via the fifth three-way valve (11) and the fourth four-way valve (12) in sequence. The outlet of the first adsorption chamber (1) is connected to the inlet of the second adsorption chamber (2) via the first waste heat valve (13), and the outlet of the second adsorption chamber (2) is connected to the inlet of the third adsorption chamber (3) via the second waste heat valve (14) in sequence. The outlet of the third adsorption chamber (3) is connected to the inlet of the first adsorption chamber (1) via the third waste heat valve (15) and the second three-way valve (8) in sequence.

4. The methane flow temperature-controlled regenerative enrichment system according to claim 1, characterized in that, It also includes a preheating module, which is used to preheat the gas to obtain hot blowing gas.

5. The methane flow temperature-controlled regenerative enrichment system according to claim 4, characterized in that, The heat source for the preheating module is geothermal, solar, or a phase change heat storage device.

6. The methane flow temperature-controlled regenerative enrichment system according to claim 1, characterized in that, It also includes a parameter measurement module, which includes a flow measurement module, a methane concentration measurement module, and a temperature measurement module. The flow measurement module is used to measure the gas flow rate at the outlet of each adsorption chamber. The methane concentration measurement module is used to measure the methane concentration at the outlet of each adsorption chamber. The temperature measurement module is used to measure the gas temperature inside each adsorption chamber and the temperature of the hot blowing gas.

7. The methane flow temperature-controlled regenerative enrichment system according to claim 1, characterized in that, The adsorbent used in the adsorption module is biomass activated carbon.

8. The methane flow temperature-controlled regenerative enrichment system according to claim 7, characterized in that, The biomass activated carbon is obtained by carbonizing walnut shells.

9. A method for the thermal enrichment of methane through flow and temperature variation, characterized in that, Based on the system described in claim 1, when the first adsorption chamber (1) is in the cold blowing adsorption section, the third adsorption chamber (3) is in the low temperature hot blowing desorption section, and the second adsorption chamber (2) is in the high temperature hot blowing desorption section, the cold raw material gas enters the first adsorption chamber (1) for methane adsorption, and the hot blowing gas passes through the second adsorption chamber (2) and the third adsorption chamber (3) in sequence for methane desorption; when the low temperature adsorbent in the third adsorption chamber (3) rises to the preset switching temperature, the cold raw material gas enters the second adsorption chamber (2) for methane adsorption, and the hot blowing gas passes through the third adsorption chamber (3) and the first adsorption chamber (1) in sequence for methane desorption; when the low temperature adsorbent in the first adsorption chamber (1) rises to the preset switching temperature, the cold raw material gas enters the third adsorption chamber (3) for methane adsorption, and the hot blowing gas passes through the first adsorption chamber (1) and the second adsorption chamber (2) in sequence for methane desorption. Thus, one cycle ends, and the above process begins to repeat.

10. The methane flow temperature-varying regenerative enrichment method according to claim 9, characterized in that, The preset switching temperature is 0.7-0.9 times the initial temperature of the hot exhaust gas.

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