Gas low-temperature dehumidification device and process

Abstract

The invention particularly relates to a gas low-temperature dehumidification device. The gas low-temperature dehumidification device comprises a first-stage condenser, a first-stage separator, a second-stage condenser, a second-stage separator, a demister and a heat regenerator, a shell side outlet of the first-stage condenser is communicated with a shell side inlet pipeline of the heat regenerator; a pipe side outlet of the first-stage condenser is communicated with an inlet pipeline of the first-stage separator, a top outlet of the first-stage separator is communicated with a pipe side inlet of the second-stage condenser, a pipe side outlet of the second-stage condenser is communicated with an inlet pipeline of the demister, an outlet of the demister is communicated with an inlet pipeline of the second-stage separator, and a top outlet of the second-stage separator is communicated with a pipe side inlet pipeline of the heat regenerator. The invention further relates to a gas low-temperature dehumidification process. The device is suitable for occasions with high temperature, high humidity and large gas flow change range, and the relative humidity of the obtained dry gas is stable and is not influenced by environmental temperature and humidity.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature gas dehumidification, and in particular to a low-temperature gas dehumidification device and process. Background Art

[0002] Low-temperature dehumidification of gas means condensing water vapor in the gas by lowering the gas temperature, separating it, and then raising the gas temperature to obtain dry gas with low relative humidity. Low-temperature dehumidification is a purely physical process. There is no adsorbent or chemical agent involved in the process, so it will not pollute the gas or change the composition of the gas. The low-temperature dehumidification process of gas is widely used in various industries such as food, pharmaceuticals, metallurgy, and air conditioning.

[0003] The existing low-temperature gas dehumidification process consists of a refrigeration system and an air duct. The wet air first exchanges heat with the low-temperature evaporator, the temperature is reduced, condensed water is precipitated, and most of the liquid is removed by the demister. The remaining gas exchanges heat with the condenser, the temperature rises, and dry gas with low relative humidity is obtained.

[0004] In order to prevent condensed water from freezing and blocking the flow channel, the refrigerant temperature in the evaporator cannot be lower than 0℃. In addition, due to the heat transfer temperature difference, the temperature of the wet air after heat exchange in the evaporator is usually around 10℃.

[0005] The existing gas low-temperature dehumidification process has the following disadvantages:

[0006] 1. In order to prevent the condensed water from freezing and blocking the flow channel, the refrigerant temperature in the evaporator cannot be lower than 0°C. In addition, due to the heat transfer temperature difference, the temperature of the wet air after heat exchange in the evaporator is usually 10°C, which makes it difficult to reach a lower dew point temperature;

[0007] 2. The existing low-temperature gas dehumidification process requires relatively stable working conditions. When the gas flow rate fluctuates greatly, the cooling temperature also fluctuates, and the moisture content of the obtained dry gas is also unstable;

[0008] 3. The demister cannot completely remove the droplets. The existing gas low-temperature dehumidification process uses a wire mesh or corrugated plate to remove the droplets entrained in the gas. The droplets cannot be completely separated. The droplets entrained in the gas are re-gasified during the heat recovery process, which increases the water content of the obtained dry gas.

[0009] Therefore, the existing low-temperature gas dehumidification process is difficult to apply to situations with high temperature, high humidity and large flow changes. Summary of the invention

[0010] The object of the present invention is to provide a low-temperature gas dehumidification process and device, which is suitable for high temperature and high humidity occasions and a large range of gas flow changes. The relative humidity of the obtained dry gas is stable and is not affected by the ambient temperature and humidity.

[0011] In order to achieve the above object, the present invention provides the following technical solutions:

[0012] A gas low-temperature dehumidification device comprises a primary condenser, a primary separator, a secondary condenser, a secondary separator, a demister and a regenerator; the shell side outlet of the primary condenser is connected to the shell side inlet pipeline of the regenerator; the tube side outlet of the primary condenser is connected to the inlet pipeline of the primary separator, the top outlet of the primary separator is connected to the tube side inlet of the secondary condenser, the tube side outlet of the secondary condenser is connected to the inlet pipeline of the demister, the demister outlet is connected to the inlet pipeline of the secondary separator, and the top outlet of the secondary separator is connected to the tube side inlet pipeline of the regenerator.

[0013] In the present invention, as one of the achievable methods, a regulating valve is provided at the shell side inlet of the primary condenser, and a first temperature sensor is provided at the shell side outlet of the primary condenser; the gas low temperature dehumidification device also includes a PLC controller;

[0014] The first temperature sensor is used to measure the shell side outlet temperature of the first-stage condenser and send it to the PLC controller;

[0015] The PLC controller is used to adjust the opening of the regulating valve according to the difference between the measured value and the set value of the shell side outlet temperature of the first-stage condenser, so as to maintain the shell side outlet temperature of the first-stage condenser at the set value.

[0016] In the present invention, as one of the achievable methods, the secondary condenser is a heat exchanger with a heat exchange medium, and the heat exchange tube bundle in the secondary condenser is immersed in the heat exchange medium; the heat exchange medium is a liquid that does not solidify or vaporize at the process temperature, including but not limited to at least one of ethylene glycol, methanol, and ethanol, or a mixture of at least one of ethylene glycol, methanol, and ethanol and water, or an inorganic salt aqueous solution of at least one of ethylene glycol, methanol, and ethanol;

[0017] A refrigeration tube is wound around the shell of the secondary condenser, and a refrigerant is arranged in the refrigeration tube; the refrigeration compressor provides cooling capacity for the refrigerant in the refrigeration tube;

[0018] A second temperature sensor is provided at the secondary condenser tube side outlet; the second temperature sensor is used to measure the secondary condenser tube side outlet temperature and send it to the PLC;

[0019] A differential pressure sensor is provided between the tube side outlet and the tube side inlet of the secondary condenser; the differential pressure sensor is used to measure the pressure drop on the tube side of the secondary condenser and send it to the PLC;

[0020] The PLC is also used to adjust the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the secondary condenser tube side outlet temperature, so as to maintain the secondary condenser tube side outlet temperature at the set value; and to adjust the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the secondary condenser tube side pressure drop, so as to maintain the secondary condenser tube side pressure drop at the set value.

[0021] In the present invention, as one of the achievable ways, the demister is a container filled with a hydrophilic material, including but not limited to a container filled with a ceramic corrugated material.

[0022] In the present invention, as one of the achievable methods, the primary separator and the secondary separator are both gas-liquid separation equipment, and the gas-liquid separation equipment includes but is not limited to a cyclone separator.

[0023] The present invention also provides a gas low-temperature dehumidification process, using the above-mentioned gas low-temperature dehumidification device, comprising the following steps:

[0024] The wet gas is fed into the tube side of the primary condenser through the tube side inlet of the primary condenser, and the cooling medium is fed into the shell side of the primary condenser through the shell side inlet of the primary condenser; the wet gas on the tube side of the primary condenser exchanges heat with the cooling medium on the shell side of the primary condenser, the wet gas is condensed in the first stage, and the cooling medium is heated; the wet gas after the first stage condensation is fed into the primary separator from the tube side outlet of the primary condenser through the inlet of the primary separator, and the heated cooling medium is fed into the shell side of the regenerator from the shell side outlet of the primary condenser through the shell side inlet of the regenerator;

[0025] The primary separator performs primary separation on the wet gas after primary condensation. The liquid after primary separation is discharged from the bottom outlet of the primary separator, and the wet gas after primary separation is sent to the tube side of the secondary condenser from the top outlet of the primary separator through the tube side inlet of the secondary condenser;

[0026] The secondary condenser performs secondary condensation on the wet gas after the primary separation; the wet gas after the secondary condensation is sent to the demister from the secondary condenser tube side outlet through the demister inlet;

[0027] The demister demisters the wet gas after the secondary condensation; the wet gas after demistering is sent from the demister outlet to the secondary separator through the secondary separator inlet;

[0028] The secondary separator performs secondary separation on the wet gas after defoaming. The liquid after secondary separation is discharged from the bottom outlet of the secondary separator, and the dry gas after secondary separation is sent from the top outlet of the secondary separator to the tube side of the regenerator through the tube side inlet of the regenerator;

[0029] The dry gas on the regenerator tube side exchanges heat with the cooling medium on the regenerator shell side, the dry gas is reheated, and the cooling medium is cooled; the reheated dry gas is discharged through the regenerator tube side outlet, and the cooled cooling medium is discharged through the regenerator shell side outlet.

[0030] In the present invention, as one of the feasible methods, during the first-stage condensation process of wet gas, the first temperature sensor measures the shell side outlet temperature of the first-stage condenser and sends it to the PLC controller; the PLC controller adjusts the opening of the regulating valve according to the difference between the measured value and the set value of the shell side outlet temperature of the first-stage condenser to maintain the shell side outlet temperature of the first-stage condenser at the set value.

[0031] In the present invention, as one of the achievable methods, during the secondary condensation of wet gas, the second temperature sensor measures the outlet temperature of the secondary condenser tube side and sends it to the PLC, and the pressure difference sensor measures the pressure drop of the secondary condenser tube side and sends it to the PLC; the PLC adjusts the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the outlet temperature of the secondary condenser tube side, so as to maintain the outlet temperature of the secondary condenser tube side at the set value; the PLC adjusts the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the pressure drop of the secondary condenser tube side, so as to maintain the pressure difference between the inlet and outlet of the secondary condenser tube side at the set value;

[0032] When the measured value of the pressure drop on the secondary condenser tube side is higher than the set value, the wet gas on the secondary condenser tube side freezes; when the measured value of the outlet temperature on the secondary condenser tube side is lower than 0°C, the wet gas on the secondary condenser tube side freezes;

[0033] When the measured value of the pressure drop on the secondary condenser tube side is higher than a certain set value, the PLC reduces the refrigeration power of the refrigeration compressor inverter to maintain the pressure drop on the secondary condenser tube side at the set value;

[0034] When the measured value of the secondary condenser tube side outlet temperature is higher than 0°C, the PLC increases the refrigeration power of the refrigeration compressor inverter to maintain the secondary condenser tube side outlet temperature at the set value.

[0035] In the present invention, as one of the achievable methods, the cooling medium includes but is not limited to cooling water and air.

[0036] Beneficial technical effects of the present invention:

[0037] The gas low-temperature dehumidification device and process of the present invention adopts a multi-stage condensation method to dehumidify the gas with high temperature, high humidity and a large flow rate variation range; uses a sensor to measure parameters to adjust the refrigeration power to prevent the gas from freezing during the cooling process; uses the cooling medium that has the first heat exchange with the gas in the first-stage condenser to recover the low-temperature saturated gas after the second-stage separation, thereby saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the existing gas low-temperature dehumidification process flow;

[0039] Figure 2 It is a structural schematic diagram of an embodiment of a gas low-temperature dehumidification device of the present invention;

[0040] Figure 3 is a schematic diagram of regulation of an embodiment of a primary condenser;

[0041] Figure 4 is a structural schematic diagram of an embodiment of a secondary condenser;

[0042] Figure 5 A schematic diagram of refrigeration power regulation of an embodiment of a refrigeration compressor;

[0043] Figure 6 A schematic diagram of the process for sampling and analyzing the gas blown out of the boiler feed water;

[0044] Figure 7 FIG. 4 is a graph showing a tube-side pressure drop and a tube-side outlet temperature of a secondary condenser according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0046] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific implementation methods.

[0048] The present invention provides a gas low-temperature dehumidification device, comprising a primary condenser, a primary separator, a secondary condenser, a secondary separator, a demister and a regenerator; the shell side outlet of the primary condenser is connected to the shell side inlet pipeline of the regenerator; the tube side outlet of the primary condenser is connected to the inlet pipeline of the primary separator, the top outlet of the primary separator is connected to the tube side inlet of the secondary condenser, the tube side outlet of the secondary condenser is connected to the inlet pipeline of the demister, the demister outlet is connected to the inlet pipeline of the secondary separator, and the top outlet of the secondary separator is connected to the tube side inlet pipeline of the regenerator.

[0049] In the present invention, as one of the achievable methods, a regulating valve is provided at the shell side inlet of the primary condenser, and a first temperature sensor is provided at the shell side outlet of the primary condenser; the gas low temperature dehumidification device also includes a PLC controller;

[0050] The first temperature sensor is used to measure the shell side outlet temperature of the first-stage condenser and send it to the PLC controller;

[0051] The PLC controller is used to adjust the opening of the regulating valve according to the difference between the measured value and the set value of the shell side outlet temperature of the first-stage condenser, so as to maintain the shell side outlet temperature of the first-stage condenser at the set value.

[0052] In the present invention, as one of the achievable methods, the secondary condenser is a heat exchanger with a heat exchange medium, and the heat exchange tube bundle in the secondary condenser is immersed in the heat exchange medium; the heat exchange medium is a liquid that does not solidify or vaporize at the process temperature, including but not limited to at least one of ethylene glycol, methanol, and ethanol, or a mixture of at least one of ethylene glycol, methanol, and ethanol and water, or an inorganic salt aqueous solution of at least one of ethylene glycol, methanol, and ethanol;

[0053] A refrigeration tube is wound around the shell of the secondary condenser, and a refrigerant is arranged in the refrigeration tube; the refrigeration compressor provides cooling capacity for the refrigerant in the refrigeration tube;

[0054] A second temperature sensor is provided at the secondary condenser tube side outlet; the second temperature sensor is used to measure the secondary condenser tube side outlet temperature and send it to the PLC;

[0055] A differential pressure sensor is provided between the tube side outlet and the tube side inlet of the secondary condenser; the differential pressure sensor is used to measure the pressure drop on the tube side of the secondary condenser and send it to the PLC;

[0056] The PLC is also used to adjust the refrigeration power of the refrigeration compressor by adjusting the frequency of the refrigeration compressor inverter according to the difference between the measured value and the set value of the secondary condenser tube side outlet temperature, so as to maintain the secondary condenser tube side outlet temperature at the set value; and adjust the refrigeration power of the refrigeration compressor by adjusting the frequency of the refrigeration compressor inverter according to the difference between the measured value and the set value of the secondary condenser tube side pressure drop, so as to maintain the secondary condenser tube side pressure drop at the set value.

[0057] In the present invention, as one of the achievable methods, the demister is a container filled with hydrophilic material, including but not limited to a container filled with ceramic corrugated material. The hydrophilic material has a large specific surface area, and can attach fine droplets in the wet gas to the surface of the hydrophilic material, and gather into large droplets, so as to facilitate removal in the subsequent process, thereby achieving the technical effect of completely separating the droplets entrained in the wet gas, preventing the droplets from re-gasifying during the heat recovery process, and increasing the water content of the obtained dry gas.

[0058] In the present invention, as one of the achievable methods, the primary separator and the secondary separator are both gas-liquid separation equipment, and the gas-liquid separation equipment includes but is not limited to a cyclone separator.

[0059] The present invention also provides a gas low-temperature dehumidification process, using the above-mentioned gas low-temperature dehumidification device, comprising the following steps:

[0060] The wet gas is fed into the tube side of the primary condenser through the tube side inlet of the primary condenser, and the cooling medium is fed into the shell side of the primary condenser through the shell side inlet of the primary condenser; the wet gas on the tube side of the primary condenser exchanges heat with the cooling medium on the shell side of the primary condenser, the wet gas is condensed in the first stage, and the cooling medium is heated; the wet gas after the first stage condensation is fed into the primary separator from the tube side outlet of the primary condenser through the inlet of the primary separator, and the heated cooling medium is fed into the shell side of the regenerator from the shell side outlet of the primary condenser through the shell side inlet of the regenerator;

[0061] The primary separator performs primary separation on the wet gas after primary condensation. The liquid after primary separation is discharged from the bottom outlet of the primary separator, and the wet gas after primary separation is sent to the tube side of the secondary condenser from the top outlet of the primary separator through the tube side inlet of the secondary condenser;

[0062] The wet gas after primary separation flows through the heat exchange tube bundle of the secondary condenser, and the refrigerant in the refrigeration tube outside the shell of the secondary condenser transfers the cold to the heat exchange medium through the shell, and the heat exchange medium transfers the cold to the wet gas after primary separation through the heat exchange tube bundle, and the wet gas after primary separation is subjected to secondary condensation; the wet gas after secondary condensation is sent to the demister from the secondary condenser tube side outlet through the demister inlet;

[0063] The demister demisters the wet gas after the secondary condensation and removes fine liquid droplets in the wet gas after the secondary condensation; the wet gas after demistering is sent from the demister outlet to the secondary separator through the secondary separator inlet;

[0064] The secondary separator performs secondary separation on the wet gas after defoaming. The liquid after secondary separation is discharged from the bottom outlet of the secondary separator, and the dry gas after secondary separation is sent from the top outlet of the secondary separator to the tube side of the regenerator through the tube side inlet of the regenerator;

[0065] The dry gas on the regenerator tube side exchanges heat with the cooling medium on the regenerator shell side, the dry gas is reheated, and the cooling medium is cooled; the reheated dry gas is discharged through the regenerator tube side outlet, and the cooled cooling medium is discharged through the regenerator shell side outlet.

[0066] The primary condenser has two functions: one is to preliminarily condense the wet gas and partially condense the water in the wet gas into liquid in order to reduce the energy consumption of subsequent processes; the other is to increase the temperature of the cooling medium to a preset range and use it as a heat source for subsequent dry gas heat recovery.

[0067] The purpose of using a heat exchange medium is to utilize the relatively large specific heat of the heat exchange medium to maintain the temperature of the secondary condenser cold source stable, so that the wet gas cooling temperature is maintained in a relatively stable range, and its cooling temperature is relatively stable even when the wet gas flow rate changes.

[0068] In the present invention, as one of the feasible methods, during the first-stage condensation process of wet gas, the first temperature sensor measures the shell side outlet temperature of the first-stage condenser and sends it to the PLC controller; the PLC controller adjusts the opening of the regulating valve according to the difference between the measured value and the set value of the shell side outlet temperature of the first-stage condenser to maintain the shell side outlet temperature of the first-stage condenser at the set value.

[0069] When the measured value of the pressure drop on the secondary condenser tube side is higher than the set value, it indicates that the refrigeration power of the refrigeration compressor is too large, and the wet gas on the secondary condenser tube side is frozen; when the temperature of the wet gas at the outlet of the secondary condenser tube side is lower than 0°C, it indicates that the refrigeration power of the refrigeration compressor is too large, and the wet gas on the secondary condenser tube side is frozen. In order to prevent the wet gas on the secondary condenser tube side from freezing, in the present invention, as one of the feasible ways, during the secondary condensation of the wet gas, the second temperature sensor measures the outlet temperature of the secondary condenser tube side and sends it to the PLC, and the pressure difference sensor measures the pressure drop on the secondary condenser tube side and sends it to the PLC; the PLC adjusts the refrigeration power of the refrigeration compressor by adjusting the frequency of the refrigeration compressor inverter according to the difference between the measured value and the set value of the outlet temperature of the secondary condenser tube side, so as to maintain the outlet temperature of the secondary condenser tube side at the set value; the PLC adjusts the refrigeration power of the refrigeration compressor by adjusting the frequency of the refrigeration compressor inverter according to the difference between the measured value and the set value of the pressure drop on the secondary condenser tube side, so as to maintain the pressure difference between the inlet and outlet of the secondary condenser tube side at the set value;

[0070] When the measured value of the pressure drop on the tube side of the secondary condenser is higher than a certain set value, the PLC reduces the refrigeration power of the refrigeration compressor inverter by reducing the frequency of the refrigeration compression molding machine inverter to maintain the pressure drop on the tube side of the secondary condenser at the set value;

[0071] When the measured value of the outlet temperature on the secondary condenser tube side is higher than 0°C, the PLC increases the refrigeration power of the refrigeration compressor inverter by increasing the frequency of the refrigeration compression molding machine inverter to maintain the outlet temperature on the secondary condenser tube side at the set value.

[0072] In the present invention, as one of the achievable methods, the cooling medium includes but is not limited to cooling water and air.

[0073] Example 1

[0074] See also Figure 2-5 The gas low-temperature dehumidification device and process of this embodiment are used for dehumidification of boiler feed water blow-out gas in a power plant before sampling, analysis and detection to protect the sampling device; the wet gas entering the primary condenser is the boiler feed water blow-out gas; the dry gas after reheating is discharged through the outlet of the reheater tube side to the sampling device for sampling, analysis and detection.

[0075] See also Figure 6 , low-pressure steam enters the deoxidation tank, mixes and bubbles evenly with the boiler feed water in the deoxidation tank, blows out the air dissolved in the boiler feed water, and obtains boiler feed water blowout gas; the boiler feed water blowout gas is a mixture of air and water vapor with a temperature higher than 100°C; in order to protect the sampling device, the boiler feed water blowout gas needs to be cooled before the sampling device, and most of the water vapor needs to be removed, so that the relative humidity of the boiler feed water blowout gas entering the sampling device is below 50%, and the temperature is close to room temperature. The power for the flow of boiler feed water blowout gas is provided by a vacuum pump.

[0076] In this embodiment, the heat exchange medium is ethylene glycol and the cooling medium is cooling water.

[0077] In this embodiment, the setting value of the secondary condenser tube side pressure drop is 0.35 kPa; the setting value of the secondary condenser tube side outlet temperature is 1°C; when the measured value of the secondary condenser tube side pressure drop is higher than 2 kPa, the PLC reduces the refrigeration power of the refrigeration compressor to maintain the secondary condenser tube side pressure drop at the set value; when the measured value of the secondary condenser tube side outlet temperature is higher than 0°C, the PLC increases the refrigeration power of the refrigeration compressor to maintain the secondary condenser tube side outlet temperature at the set value.

[0078] See also Figure 7 This example records the secondary condenser tube side pressure drop and tube side outlet temperature within 8 hours. The test shows that the advantage of the secondary condenser adjustment method is that a lower cooling temperature can be obtained, so it has a better dehumidification effect than the existing gas low temperature dehumidification process.

[0079] In this embodiment, the process parameters of low-temperature gas dehumidification are shown in Table 1.

[0080] Table 1 Gas low temperature dehumidification process parameters of this embodiment

[0081]

[0082]

[0083] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A gas dehumidification device, characterized in that: It includes a primary condenser, a primary separator, a secondary condenser, a secondary separator, a demister and a regenerator; the shell side outlet of the primary condenser is connected to the shell side inlet pipeline of the regenerator; the tube side outlet of the primary condenser is connected to the inlet pipeline of the primary separator, the top outlet of the primary separator is connected to the tube side inlet of the secondary condenser, the tube side outlet of the secondary condenser is connected to the inlet pipeline of the demister, the demister outlet is connected to the inlet pipeline of the secondary separator, and the top outlet of the secondary separator is connected to the tube side inlet pipeline of the regenerator.

2. The gas dehumidification device according to claim 1, characterized in that: A regulating valve is provided at the shell side inlet of the first-stage condenser, and a first temperature sensor is provided at the shell side outlet of the first-stage condenser; the gas dehumidification device also includes a PLC controller; The first temperature sensor is used to measure the shell side outlet temperature of the first-stage condenser and send it to the PLC controller; The PLC controller is used to adjust the opening of the regulating valve according to the difference between the measured value and the set value of the shell side outlet temperature of the first-stage condenser, so as to maintain the shell side outlet temperature of the first-stage condenser at the set value.

3. The gas dehumidification device according to claim 1, characterized in that: The secondary condenser is a heat exchanger with a heat exchange medium, and the heat exchange tube bundle in the secondary condenser is immersed in the heat exchange medium; the heat exchange medium is a liquid that does not solidify or vaporize at the process temperature; A refrigeration tube is wound around the shell of the secondary condenser, and a refrigerant is arranged in the refrigeration tube; the refrigeration compressor provides cooling capacity for the refrigerant in the refrigeration tube; A second temperature sensor is provided at the secondary condenser tube side outlet; the second temperature sensor is used to measure the secondary condenser tube side outlet temperature and send it to the PLC; A differential pressure sensor is provided between the tube side outlet and the tube side inlet of the secondary condenser; the differential pressure sensor is used to measure the pressure drop on the tube side of the secondary condenser and send it to the PLC; The PLC is also used to adjust the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the secondary condenser tube side outlet temperature, so as to maintain the secondary condenser tube side outlet temperature at the set value; and to adjust the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the secondary condenser tube side pressure drop, so as to maintain the secondary condenser tube side pressure drop at the set value.

4. The gas dehumidification device according to claim 3, characterized in that: The heat exchange medium is at least one of ethylene glycol, methanol, and ethanol, or a mixture of at least one of ethylene glycol, methanol, and ethanol and water, or an inorganic salt aqueous solution of at least one of ethylene glycol, methanol, and ethanol.

5. The gas dehumidification device according to claim 1, characterized in that: The demister is a container filled with hydrophilic material.

6. The gas dehumidification device according to claim 1, characterized in that: Both the primary separator and the secondary separator are gas-liquid separation equipment.

7. A gas dehumidification process, characterized in that: The steps include: The wet gas is fed into the tube side of the primary condenser through the tube side inlet of the primary condenser, and the cooling medium is fed into the shell side of the primary condenser through the shell side inlet of the primary condenser; the wet gas on the tube side of the primary condenser exchanges heat with the cooling medium on the shell side of the primary condenser, the wet gas is condensed in the first stage, and the cooling medium is heated; the wet gas after the first stage condensation is fed into the primary separator from the tube side outlet of the primary condenser through the inlet of the primary separator, and the heated cooling medium is fed into the shell side of the regenerator from the shell side outlet of the primary condenser through the shell side inlet of the regenerator; The primary separator performs primary separation on the wet gas after primary condensation. The liquid after primary separation is discharged from the bottom outlet of the primary separator, and the wet gas after primary separation is sent to the tube side of the secondary condenser from the top outlet of the primary separator through the tube side inlet of the secondary condenser; The secondary condenser performs secondary condensation on the wet gas after the primary separation; the wet gas after the secondary condensation is sent to the demister from the secondary condenser tube side outlet through the demister inlet; The demister demisters the wet gas after the secondary condensation; the wet gas after demistering is sent from the demister outlet to the secondary separator through the secondary separator inlet; The secondary separator performs secondary separation on the wet gas after defoaming. The liquid after secondary separation is discharged from the bottom outlet of the secondary separator, and the dry gas after secondary separation is sent from the top outlet of the secondary separator to the tube side of the regenerator through the tube side inlet of the regenerator; The dry gas on the regenerator tube side exchanges heat with the cooling medium on the regenerator shell side, the dry gas is reheated, and the cooling medium is cooled; the reheated dry gas is discharged through the regenerator tube side outlet, and the cooled cooling medium is discharged through the regenerator shell side outlet.

8. The gas dehumidification process according to claim 7, characterized in that: During the primary condensation of wet gas, the first temperature sensor measures the shell outlet temperature of the primary condenser and sends it to the PLC controller; the PLC controller adjusts the opening of the regulating valve according to the difference between the measured value and the set value of the shell outlet temperature of the primary condenser to maintain the shell outlet temperature of the primary condenser at the set value.

9. The gas dehumidification process according to claim 7, characterized in that: During the secondary condensation of wet gas, the second temperature sensor measures the secondary condenser tube side outlet temperature and sends it to the PLC, and the pressure difference sensor measures the secondary condenser tube side pressure drop and sends it to the PLC; the PLC adjusts the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the secondary condenser tube side outlet temperature to maintain the secondary condenser tube side outlet temperature at the set value; the PLC adjusts the refrigeration power of the refrigeration compressor according to the difference between the measured value and the set value of the secondary condenser tube side pressure drop to maintain the pressure difference between the secondary condenser tube side inlet and the tube side outlet at the set value; When the measured value of the pressure drop on the secondary condenser tube side is higher than the set value, the wet gas on the secondary condenser tube side freezes; when the measured value of the outlet temperature on the secondary condenser tube side is lower than 0°C, the wet gas on the secondary condenser tube side freezes; When the measured value of the pressure drop on the secondary condenser tube side is higher than a certain set value, the PLC reduces the refrigeration power of the refrigeration compressor inverter to maintain the pressure drop on the secondary condenser tube side at the set value; When the measured value of the outlet temperature on the secondary condenser tube side is higher than 0°C, the PLC increases the refrigeration power of the refrigeration compressor to maintain the outlet temperature on the secondary condenser tube side at the set value.

10. The gas dehumidification process according to claim 9, characterized in that: The wet gas entering the primary condenser is the boiler feed water blow-off gas; The set value of the secondary condenser tube side pressure drop is 0.35kPa; the set value of the secondary condenser tube side outlet temperature is 1℃; When the measured value of the pressure drop on the secondary condenser tube side is higher than 2kPa, the PLC reduces the refrigeration power of the refrigeration compressor to maintain the pressure drop on the secondary condenser tube side at the set value; When the measured value of the outlet temperature on the secondary condenser tube side is higher than 0°C, the PLC increases the refrigeration power of the refrigeration compressor to maintain the outlet temperature on the secondary condenser tube side at the set value.

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