Device for reducing humidity of low-concentration gas and dehumidification method

Abstract

The invention discloses a device for reducing the humidity of low-concentration gas and a dehumidification method. The device comprises a dehumidification tower, a gas-liquid separator, a dehumidification liquid constant temperature heat exchanger, a dehumidification liquid regeneration tower and a heat source, wherein the low-concentration gas enters the dehumidification tower through the gas-liquid separator, a dehumidification liquid discharging port and a liquid return port are also formed in the dehumidification tower; a dehumidification liquid passes through the dehumidification liquid constant temperature heat exchanger by the dehumidification liquid discharging port, then enters the dehumidification liquid regeneration tower to be regenerated, and finally returns to the dehumidification tower to be continuously dehumidified by the liquid return port of the dehumidification tower; and the dehumidification liquid regeneration tower also comprises a regeneration air draught fan. According to the device, the concentration of gas can be effectively controlled by adjusting the concentration of an absorbent, so that the dew point temperature of the gas is reduced; the waste heat of smoke discharged by a gas turbine is used as a main energy source, so that the energy consumption of the device is greatly reduced, and as the flow resistance is low, the gas only needs to pass through the dehumidification tower and no longer needs to flow through the heat exchanger with large loss of pressure, and therefore, the operation security of the low-concentration gas is ensured.

Description

technical field [0001] The invention belongs to the field of energy, and in particular relates to a device and a dehumidification method for reducing the humidity of low-concentration gas. Background technique [0002] At present, the utilization process of low-concentration gas in my country generally includes: [0003] Downhole drainage of low-concentration gas (>10%) → water mist transportation → dehumidification → unit power generation. [0004] Low-concentration gas refers to the air mixture with a methane concentration between 3% and 30%. To ensure safety, according to national regulations, the gas will be humidified by spraying water mist to ensure safe transportation. Humidity has brought great difficulties to the subsequent utilization of gas: [0005] (1) A large amount of condensed water is easily mixed with dust, causing the pipe system to be blocked or the valve to be stuck; [0006] (2) During combustion and utilization, ignition is difficult and thermal ...

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Problems solved by technology

[0004] Low-concentration gas refers to the air mixture with a methane concentration between 3% and 30%. To ensure safety, according to national regulations, the gas will be humidified by spraying water mist to ensure safe transportation. Humidity has brought great difficulties to the subsequent utilization of gas:

[0005] (1) A large amount of condensed water is easily mixed with dust, causing the pipe system to be blocked or the valve to be stuck;

[0006] (2) During combustion and utilization, ignition is difficult and thermal efficiency decreases due to the presence of moisture

[0010] In this field, the traditional dehumidification method is to use low-temperature dehumidification, that is, to use refrigeration equipment to reduce the gas temperature to about 7°C, so that the relative humidity increases and the gas temperature is restored after the condensed water comes out, so that the relative humidity of the gas can be reduced. , but this method has high energy consumption. For low-concentration gas, its energy density is low and its power generation capacity is weak. The high dehumidification energy consumption greatly offsets the energy output of the system. Consumed within the system without any output

Traditional low-concentration gas dehumidification adopts electric refrigeration, which consumes a lot of energy to process gas. It needs about 30kw per 2000 cubic meters per hour, and because of its low concentration, the power generation is only 350kw-400kw

[0011] In addition, due to the special requirements of low-concentration gas transportation and utilization equipment, the pressure loss of gas treatment and purification should not be too large, and the current dehumidification heat exchanger has a large pressure loss and consumes more energy

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