In-situ fuel gas thermal desorption waste heat driven combined cooling and power supply system and method

Abstract

The invention discloses an in-situ fuel gas thermal desorption waste heat driven combined cooling and power system and method. The system comprises a waste gas input pipeline, a waste gas heat exchange module, an organic working medium cycle power generation module, an absorption type refrigeration cycle module and a tail gas heat exchange module. One end of a waste gas input pipeline is communicated with a combustion-supporting flue gas outlet of a heating well of a thermal desorption heating field, the other end of the waste gas input pipeline is connected with a waste gas heat exchange module, an outlet of the waste gas heat exchange module is connected with a first pipeline and a second pipeline, the first pipeline is communicated with an organic working medium cycle power generation module, and the second pipeline is sequentially communicated with an absorption refrigeration cycle module and a tail gas heat exchange module. One end of the tail gas heat exchange module is communicated with a thermal desorption heating field extraction wellhead. Waste heat generated after polluted soil is heated by combustion-supporting waste gas of the in-situ fuel gas thermal desorption burner is used as power, the organic working medium cycle power generation module is driven to provide electric energy for the in-situ thermal desorption system, and the absorption type refrigeration cycle module is driven to provide cold energy for the in-situ thermal desorption tail gas treatment system. And cold and power combined supply of the system is realized while the waste heat of the waste gas is utilized.

Description

Technical Field

[0001] The present invention relates to the field of waste heat utilization of soil thermal remediation technology, and in particular to a combined cooling and power generation system and method driven by waste heat from in-situ gas thermal desorption. Background Art

[0002] During the process of remediation of contaminated sites using in-situ gas thermal desorption technology, during the site heating process, the high-temperature exhaust gas generated by the combustion of natural gas heats the underground contaminated soil by heat conduction, and the outlet exhaust gas temperature is generally still between 200 and 350°C. The direct emission of a large amount of this waste heat causes a large waste of energy.

[0003] At the same time, in thermal desorption projects, a large number of combustion-supporting fans are often needed to discharge combustion exhaust gas, which has a large electrical load demand; and because the temperature of the combustion-supporting fan is high, exceeding the maximum temperature that the fan bearing can withstand, it is currently necessary to cool the exhaust gas intake before the fan, which generates additional energy consumption. On the other hand, the in-situ thermal desorption tail gas extracted from the contaminated site is a high-temperature gas (generally at 80-100°C) containing a large amount of water vapor and a large number of pollutants such as VOCs and SVOCs. Before entering the tail gas treatment unit such as terminal activated carbon adsorption or high-temperature oxidation, the tail gas extracted from the site needs to be deeply cooled and condensed, so it has a large cooling capacity demand.

[0004] In the context of dual carbon, for in-situ gas thermal desorption technology, how to fully utilize the thermal energy of natural gas combustion, improve the comprehensive energy utilization rate of the system, and achieve overall energy saving and consumption reduction of the system is an important issue currently faced. Summary of the invention

[0005] The purpose of the present invention is to provide a waste heat-driven cooling and power cogeneration system and method for in-situ gas thermal desorption. By using the low-grade waste heat brought by the heat conduction of the combustion-supporting waste gas of multiple burners in the in-situ gas thermal desorption to heat the contaminated soil as the driving force, on the one hand, the organic working fluid circulation power generation module provides electric energy for the in-situ thermal desorption system to reduce the power consumption of the system; on the other hand, the absorption refrigeration cycle module provides cold energy for the in-situ thermal desorption system, and the cold energy is used for the condensation, cooling and dehumidification of the high-temperature tail gas extracted by the thermal desorption, while realizing the full recovery and utilization of the low-temperature waste heat of the exhaust gas, the comprehensive energy utilization rate of the system and the tail gas treatment effect are improved.

[0006] The present invention adopts the following technical solutions:

[0007] An in-situ gas thermal desorption waste heat driven cooling and power cogeneration system, characterized by: comprising an exhaust gas input pipeline, an exhaust gas heat exchange module, an organic working fluid circulation power generation module, an absorption refrigeration cycle module, and an exhaust gas heat exchange module. One end of the exhaust gas input pipeline is connected to multiple heating well combustion flue gas outlets in the thermal desorption additional heating site, and the other end is connected to the exhaust gas heat exchange module. The outlet of the exhaust gas heat exchange module is connected to pipeline 1 and pipeline 2. The pipeline 1 is connected to the organic working fluid circulation power generation module, and the pipeline 2 is connected to the absorption refrigeration cycle module and the exhaust gas heat exchange module in sequence. One end of the exhaust gas heat exchange module is connected to multiple extraction wells in the thermal desorption additional heating site.

[0008] The heating wells include horizontal heating wells and vertical heating wells. The extraction wells include horizontal extraction wells and vertical extraction wells.

[0009] The exhaust gas heat exchange module includes a combustion-supporting fan for discharging heat removal and additional heating site heating well combustion exhaust gas, an exhaust gas heat exchanger, a water tank for storing hot water after heat exchange, and a hot water pump. The exhaust gas heat exchanger is arranged between the exhaust gas input pipeline and the combustion-supporting fan inlet pipeline.

[0010] The organic working fluid circulation power generation module includes a first evaporator, a turbine, a first condenser, and a first working fluid pump which are sequentially connected through pipelines. The turbine is connected to a generator, and the generator is connected to an on-site electrical device for thermal desorption of in-situ gas. The refrigerant outlet of the first condenser is connected to a first cooling tower return port, the refrigerant inlet is connected to a first cooling water circulation pump outlet pipeline, and the heat source inlet of the first evaporator is connected to a hot water pump outlet pipeline.

[0011] The absorption refrigeration cycle module includes a generator, a solution heat exchanger, an absorber, a circulation pump, a second condenser, a second evaporator, a second cooling tower, and a second cooling water circulation pump. The generator, the second condenser, the second evaporator, the absorber, and the solution heat exchanger are connected in sequence, a throttle valve is provided between the second condenser and the second evaporator, the second evaporator is provided with a refrigerant pump, the refrigerant outlet of the second condenser is connected to the return water pipeline of the second cooling tower, and the outlet pipeline of the second cooling water circulation pump performs countercurrent heat exchange in the absorber and the second condenser in turn. The heat source inlet of the generator is connected to the second outlet pipeline of the hot water pump.

[0012] The tail gas heat exchange module includes a tail gas secondary heat exchanger, an extraction well, a tail gas primary heat exchange unit, and a subsequent tail gas treatment unit. The chilled water inlet and outlet ends of the tail gas secondary heat exchanger are respectively connected to the second evaporator chilled water outlet and inlet pipelines.

[0013] The exhaust gas input pipeline, the exhaust gas heat exchanger, the water storage tank, and the pipelines 1 and 2 from the hot water pump outlet to the organic working fluid circulation power generation module and the absorption refrigeration cycle module are provided with insulation; the chilled water delivery pipeline between the second evaporator of the absorption refrigeration cycle system and the secondary tail gas heat exchanger is provided with cold insulation.

[0014] Preferably, the exhaust gas heat exchanger in the exhaust gas heat exchange module adopts a plate heat exchanger.

[0015] Preferably, the organic working fluid circulation power generation module uses R123, R245fa, etc. as the circulating working fluid.

[0016] Preferably, the absorption refrigeration cycle module uses lithium bromide aqueous solution as the refrigerant.

[0017] Preferably, the secondary exhaust gas heat exchanger in the exhaust gas heat exchange module is a shell-and-tube heat exchanger.

[0018] The in-situ gas thermal desorption waste heat driven cooling and power cogeneration method of the present invention adopts the following technical scheme: an in-situ gas thermal desorption waste heat driven cooling and power cogeneration method, comprising the following steps:

[0019] (1) The combustion-supporting exhaust gas from multiple heating wells in the in-situ gas thermal degassing and heating site is collected and sent to the exhaust gas heat exchanger through the combustion-supporting fan to exchange heat with process water. The temperature of the hot water after the exhaust gas heat exchanger is 85-150°C. The heated process water is sent to the water storage tank for storage and connected to pipeline 1 and pipeline 2 through a hot water pump;

[0020] (2) The hot water after the exhaust gas heat exchange is used as the heat source and transported to the first evaporator of the organic working fluid circulation power generation module through pipeline 1. The organic working fluid absorbs heat in the first evaporator to generate steam, which drives the turbine to expand and do work, drives the generator to generate electricity, and continuously supplies power to the electrical equipment on the thermal desorption site;

[0021] (3) The hot water after the exhaust gas heat exchange is used as the heat source and is transported to the absorption refrigeration cycle module generator through pipeline 2. The system working fluid absorbs heat in the generator, condenses in the second condenser, and expands through throttling. It vaporizes in the second evaporator and absorbs the heat of the cooling water to generate low-temperature chilled water. The chilled water outlet / return water temperature is 7 / 12°C, and the cooling capacity can be adjusted within the load range of 20-100%;

[0022] (4) The chilled water prepared by the absorption refrigeration cycle system is transported to the heat exchange tube in the exhaust gas secondary heat exchanger. The extracted exhaust gas that has passed through the front-end exhaust gas primary heat exchange by in-situ fuel gas thermal desorption is countercurrently exchanged with the chilled water in the exhaust gas secondary heat exchanger to achieve deep condensation, cooling, dehumidification and reduction of the exhaust gas treatment load.

[0023] Due to the adoption of the above technical solution, the present invention has at least the following beneficial effects:

[0024] (1) The low-grade waste heat from the combustion-supporting exhaust gas of multiple burners in the in-situ gas thermal desorption system is used as the driving force to heat the contaminated soil, and the organic working fluid circulation power generation module is driven to supply power to the electrical equipment of the in-situ thermal desorption system, making full use of the waste heat of the exhaust gas while reducing the power consumption of the system;

[0025] (2) Using the waste heat of the combustion-supporting exhaust gas from the in-situ thermal desorption of fuel gas as the driving force, the absorption refrigeration cycle module provides cold energy for the in-situ thermal desorption system, and uses the cold energy for deep condensation and dehumidification of the high-temperature exhaust gas extracted by thermal desorption. While recycling the low-temperature waste heat of the exhaust gas, it meets the cooling capacity demand for exhaust gas treatment, improves the exhaust gas treatment effect, and reduces the subsequent exhaust gas treatment load;

[0026] (3) The overall recovery and utilization of low-temperature waste heat from exhaust gas has been achieved, thereby improving the overall energy utilization rate of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0028] in:

[0029] Figure 1 A schematic diagram of a combined cooling and power generation system driven by waste heat from in-situ gas thermal desorption according to the present invention;

[0030] Among them, 1-heating well; 2-combustion-supporting fan; 3-exhaust gas heat exchanger; 4-water storage tank; 5-hot water pump; 6-organic working fluid circulation power generation module; 7-absorption refrigeration cycle module; 8-exhaust gas secondary heat exchanger; 9-extraction well; 10-exhaust gas primary heat exchanger; 11-subsequent exhaust gas treatment unit.

[0031] 61 - first evaporator; 62 - turbine; 63 - generator; 64 - first condenser; 65 - first working fluid pump; 66 - first cooling tower; 67 - first cooling water circulation pump.

[0032] 71-generator; 72-solution heat exchanger; 73-absorber; 74-circulation pump; 75-second condenser; 76-throttle valve; 77-second evaporator; 78-working fluid pump 2; 79-second cooling tower; 710-second cooling water circulation pump. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with the accompanying drawings and examples. In the following detailed description, certain exemplary embodiments of the present invention are described only by way of illustration. Needless to say, those of ordinary skill in the art will recognize that the described embodiments may be modified in various ways without departing from the spirit and scope of the present invention. Therefore, the drawings and description are illustrative in nature and are not intended to limit the scope of protection of the claims.

[0034] Implementation Case 1

[0035] refer to Figure 1 The present invention discloses an in-situ gas thermal desorption waste heat driven cooling and power cogeneration system, comprising a waste gas input pipeline, a waste gas heat exchange module, an organic working fluid circulation power generation module 6, an absorption refrigeration cycle module 7 and an exhaust gas heat exchange module. One end of the waste gas input pipeline is connected to the combustion-supporting flue gas outlets of multiple horizontal and vertical heating wells on the in-situ gas thermal desorption heating field, and the other end is connected to the waste gas heat exchange module. The outlet of the waste gas heat exchange module is connected to pipeline 1 and pipeline 2. Pipeline 1 is connected to the organic working fluid circulation power generation module 6, and pipeline 2 is connected to the absorption refrigeration cycle module 7 and the exhaust gas heat exchange module in sequence. One end of the exhaust gas heat exchange system is connected to multiple horizontal and vertical extraction wellheads on the thermal desorption heating field.

[0036] The exhaust gas heat exchange module is composed of a combustion-supporting fan 2 for discharging the exhaust gas from the heating well of the heat removal and additional heating site, an exhaust gas heat exchanger 3, a water tank 4 for storing hot water after heat exchange, and a hot water pump 5. The exhaust gas heat exchanger 3 is arranged on the pipeline between the exhaust gas input pipeline and the combustion-supporting fan inlet.

[0037] The organic working fluid circulation power generation module 6 includes a first evaporator 61, a turbine 62, a first condenser 64, and a first working fluid pump 65 which are sequentially connected through pipelines. The turbine 62 is connected to the generator 63, and the generator 63 is connected to the on-site fan, pump and other electrical equipment for the in-situ gas thermal desorption. The refrigerant outlet of the first condenser 64 is connected to the return water port of the first cooling tower 66, and the refrigerant inlet is connected to the outlet pipeline of the first cooling water circulation pump 67. The heat source inlet of the first evaporator 61 is connected to the outlet pipeline of the hot water pump 5.

[0038] The absorption refrigeration cycle module 7 includes a generator 71, a solution heat exchanger 72, an absorber 73, a circulation pump 74, a second condenser 75, a second evaporator 77, a second cooling tower 79, and a second cooling water circulation pump 710. The generator 71, the second condenser 75, the second evaporator 77, the absorber 73, and the solution heat exchanger 72 are connected in sequence, a throttle valve 76 is provided between the second condenser 75 and the second evaporator 77, a refrigerant pump 78 is provided in the second evaporator 77, the refrigerant outlet of the second condenser 75 is connected to the return water pipeline of the second cooling tower 79, and the outlet pipeline of the second cooling water circulation pump 710 is countercurrently heat exchanged in the absorber 73 and the second condenser 75. The heat source inlet of the generator is connected to the outlet pipeline 2 of the hot water pump 5.

[0039] The tail gas heat exchange module includes a tail gas secondary heat exchanger 8, an extraction well 9, a tail gas primary heat exchange unit 10, and a subsequent tail gas treatment unit 11. The chilled water inlet and outlet of the tail gas secondary heat exchanger 8 are respectively connected to the chilled water outlet and inlet pipelines of the second evaporator 77.

[0040] In order to reduce heat loss, the exhaust gas input pipeline, the exhaust gas heat exchanger 3, the water storage tank 4, and the pipeline 1 and pipeline 2 from the outlet of the hot water pump 5 to the organic working medium circulation power generation module and the absorption refrigeration cycle module are provided with thermal insulation; the chilled water delivery pipeline between the second evaporator of the absorption refrigeration cycle module and the secondary heat exchanger of the tail gas is provided with cold insulation. Rock wool, polyurethane and other materials can be used for thermal insulation and cold insulation.

[0041] The working process of this implementation case is as follows:

[0042] In the process of in-situ gas thermal decontamination of the contaminated site, the high-temperature exhaust gas generated by the combustion of natural gas heats the underground contaminated soil by heat conduction through the concentric heating pipe, and then discharges the exhaust gas at about 200-350°C. The flue gas from multiple heating wells is collected by the combustion-supporting fan 2 and sent to the plate-type exhaust gas heat exchanger 3 to exchange heat with the heat medium water. The heat medium water absorbs the heat of the flue gas, and the outlet temperature rises to 85-150°C. Considering the instability of flue gas emissions, the system is designed with a water storage tank 4 to store hot water.

[0043] The heat medium water after the heat exchange is used as the heat source for power supply. The hot water is transported to the organic working fluid circulation power generation module 6 through the hot water pump 5 through the pipeline 1. In this module, the circulating working fluid absorbs heat from the waste water after the flue gas heat exchange in the first evaporator 61 and becomes superheated steam. The steam enters the turbine 62 to expand and do work, driving the generator 63 to generate electricity. The exhaust gas that has done work in the turbine 62 enters the first condenser 64 to be recooled into liquid, and is pumped into the evaporator by the working fluid pump for recycling and reuse to achieve continuous low-temperature waste heat power generation. The generated electricity is used to drive the fans, pumps and other electrical equipment of the in-situ gas thermal desorption system. For the in-situ thermal desorption project, the demand for external power supply can be reduced. For the low-temperature exhaust gas waste heat recovery power generation of 200-350℃, R123, R245fa, etc. are often used as circulating working fluids. Table 1 lists the physical property index comparison table of several commonly used working fluids. Taking a small-scale in-situ gas thermal desorption pilot project as an example, the exhaust gas temperature of the combustion-supporting exhaust gas is 220°C and the exhaust gas flow rate is 20,000 m 3 / h, using it as a heat source for organic working fluid circulation power generation, using R245fa as the organic circulating working fluid, deducting the power consumption of the first working fluid pump 65 and the power consumption of the first cooling water circulation pump 67, about 100kW of electricity can be generated per hour. When used to power in-situ thermal desorption equipment such as combustion-supporting fans and pumps, the corresponding power consumption can be saved.

[0044] Table 1 Physical properties of several commonly used organic working fluids

[0045]

[0046] The heat medium water after the heat exchange of the combustion exhaust gas is used as the heat source for cooling. The hot water is transported to the generator 71 of the absorption refrigeration cycle module 7 using the lithium bromide aqueous solution as the working medium through the hot water pump 5 through the pipeline 2. When the lithium bromide aqueous solution is heated by the heat medium water in the generator, the water in the solution is continuously vaporized; as the water is continuously vaporized, the concentration of the lithium bromide aqueous solution in the generator 71 is continuously increased and enters the absorber 73; the water vapor enters the second condenser 75, is cooled by the cooling water in the second condenser 75, and then condenses into high-pressure and low-temperature liquid water; when the water in the second condenser 75 passes through the throttle valve 76 After entering the second evaporator 77, it expands and vaporizes rapidly. During the vaporization process, it absorbs a large amount of heat from the cooling water of the second evaporator 77, turning it into 7°C low-temperature chilled water at the outlet, and then transported to the secondary exhaust heat exchanger 8 in the exhaust heat exchange module to cool and condense the thermally desorbed exhaust gas. During this process, the low-temperature water vapor enters the absorber 73 and is absorbed by the lithium bromide aqueous solution in the absorber 73. The concentration of the solution gradually decreases and is sent back to the generator 71 after being heated by the circulating pump 74 through the solution heat exchanger 72 and the high-temperature concentrated solution flowing out of the generator 71, completing the entire refrigeration cycle. In the secondary exhaust heat exchanger 8, the water vapor and pollutant components in the thermally desorbed exhaust gas are condensed, and the temperature and humidity are reduced. At the same time, the exhaust pollution load before entering the subsequent exhaust treatment unit 11 such as activated carbon adsorption and high-temperature oxidation is further reduced, which is beneficial to the subsequent exhaust treatment. Taking a small-scale in-situ fuel gas thermal desorption pilot project as an example, the exhaust gas emission temperature of the combustion-supporting exhaust gas is 220°C and the exhaust gas flow rate is 20,000 m 3 / h, the inlet and outlet temperatures of the hot water side are 98℃, and 454kW of heat from the combustion-supporting exhaust gas can be recovered. The recovered heat can be used to drive a hot water-type lithium bromide refrigeration unit (cooling capacity 300kW), and the cold energy can be used for deep cooling and condensation of the thermal desorption exhaust gas.

[0047] By recycling the waste heat from thermal desorption combustion-supporting exhaust gas, the system achieves combined cooling and electricity supply, and overall realizes the comprehensive recycling and utilization of low-temperature waste heat from exhaust gas, thereby improving the comprehensive energy utilization rate of the system.

Claims

1. An in-situ gas thermal desorption waste heat driven cooling and power cogeneration system, characterized by: The invention comprises a waste gas input pipeline, a waste gas heat exchange module, an organic working fluid circulation power generation module (6), an absorption refrigeration circulation module (7), and a tail gas heat exchange module; one end of the waste gas input pipeline is connected to a plurality of heating wells (1) of a heat removal additional heating site and a combustion-supporting flue gas outlet, and the other end is connected to the waste gas heat exchange module; the outlet of the waste gas heat exchange module is connected to pipeline 1 and pipeline 2; pipeline 1 is connected to the organic working fluid circulation power generation module (6); pipeline 2 is connected to the absorption refrigeration circulation module (7) and the tail gas heat exchange module in sequence; one end of the tail gas heat exchange module is connected to a plurality of extraction wells (9) of a heat removal additional heating site.

2. According to claim 1, an in-situ gas thermal desorption waste heat driven combined cooling and power system is characterized by: The heating well (1) includes a horizontal heating well and a vertical heating well; the extraction well (9) includes a horizontal extraction well and a vertical extraction well.

3. The in-situ gas thermal desorption waste heat driven combined cooling and power system according to claim 1, characterized in that: The exhaust gas heat exchange module comprises a combustion-supporting fan (2) for discharging heat removal and heating site heating well combustion exhaust gas, an exhaust gas heat exchanger (3), a water storage tank (4) for storing hot water after heat exchange, and a hot water pump (5), wherein the exhaust gas heat exchanger (3) is arranged between the exhaust gas input pipeline and the combustion-supporting fan inlet pipeline.

4. The in-situ gas thermal desorption waste heat driven combined cooling and power system according to claim 3, characterized in that: The organic working fluid circulation power generation module (6) comprises a first evaporator (61), a turbine (62), a first condenser (64), and a first working fluid pump (65) which are connected in sequence through pipelines; the turbine (62) is connected to a generator (63), and the generator (63) is connected to an on-site electrical device for thermal desorption of in-situ fuel gas; the refrigerant outlet of the first condenser (64) is connected to a water return port of a first cooling tower (66), the refrigerant inlet is connected to an outlet pipeline of a first cooling water circulation pump (67), and the heat source inlet of the first evaporator (61) is connected to an outlet pipeline of a hot water pump (5).

5. The in-situ gas thermal desorption waste heat driven combined cooling and power system according to claim 3, characterized in that: The absorption refrigeration cycle module (7) comprises a generator (71), a solution heat exchanger (72), an absorber (73), a circulation pump (74), a second condenser (75), a second evaporator (77), a second cooling tower (79), and a second cooling water circulation pump (710); the generator (71), the second condenser (75), the second evaporator (77), the absorber (73), and the solution heat exchanger (72) are connected in sequence, a throttle valve (76) is provided between the second condenser (75) and the second evaporator (77), the second evaporator (77) is provided with a refrigerant pump (78), the refrigerant outlet of the second condenser (75) is connected to the return water pipeline of the second cooling tower (79), and the outlet pipeline of the second cooling water circulation pump (710) performs countercurrent heat exchange in the absorber (73) and the second condenser (75) in turn; the heat source inlet of the generator is connected to the outlet pipeline of the hot water pump (5).

6. The in-situ gas thermal desorption waste heat driven combined cooling and power system according to claim 5, characterized in that: The exhaust gas heat exchange module comprises an exhaust gas secondary heat exchanger (8), an exhaust gas primary heat exchange unit (10), and a subsequent exhaust gas treatment unit (11); the chilled water inlet and outlet ends of the exhaust gas secondary heat exchanger (8) are respectively connected to the chilled water outlet and inlet pipelines of the second evaporator (77).

7. The in-situ gas thermal desorption waste heat driven combined cooling and power system according to claim 5, characterized in that: The waste gas input pipelines, pipeline 1 and pipeline 2, are provided with a heat preservation layer; and the chilled water delivery pipeline between the second evaporator (77) of the absorption refrigeration cycle module (7) and the tail gas secondary heat exchanger (8) is provided with a cold preservation layer.

8. An in-situ gas thermal desorption waste heat driven combined cooling and power generation method according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: The combustion-supporting exhaust gas from multiple heating wells (1) in the in-situ gas thermal degassing and additional heating site is collected and sent to the exhaust gas heat exchanger (3) through the combustion-supporting fan to exchange heat with process water. The heated process water is sent to the water storage tank (4) for storage and connected to pipeline 1 and pipeline 2 through the hot water pump (5); Step 2: using the hot water after the waste gas heat exchange as a heat source, the hot water is transported to the first evaporator (61) of the organic working medium circulation power generation module (6) through pipeline 1, and the organic working medium absorbs heat in the first evaporator (61) to generate steam, which drives the turbine (62) to expand and do work, driving the generator to generate electricity, and continuously supplying power to the electrical equipment on the thermal desorption site; Step 3: The hot water after the waste gas heat exchange is used as a heat source and is transported to the generator (71) of the absorption refrigeration cycle module (7) through pipeline 2. The system working fluid absorbs heat through the generator (71), is condensed in the second condenser (75), and is throttled and expanded. It is vaporized in the second evaporator (77) and absorbs the heat of the cooling water to generate low-temperature chilled water. Step 4: The chilled water prepared by the absorption refrigeration cycle module is transported to the heat exchange pipe in the exhaust gas secondary heat exchanger (8). The extracted exhaust gas that has undergone the front-end exhaust gas primary heat exchange extracted by the in-situ fuel gas thermal desorption is subjected to countercurrent heat exchange with the chilled water in the exhaust gas secondary heat exchanger (8), thereby achieving deep condensation, cooling, dehumidification and reduction of the exhaust gas treatment load.

9. The method for driving combined cooling and power generation by waste heat from in-situ gas thermal desorption according to claim 8, characterized in that: The temperature of hot water passing through the exhaust gas heat exchanger ranges from 85-150°C.

10. The method for driving combined cooling and power generation by waste heat from in-situ gas thermal desorption according to claim 8, characterized in that: The chilled water outlet / return water temperature prepared by the absorption refrigeration cycle module is 7 / 12°C, and the refrigeration capacity can be adjusted within a load range of 20 to 100%.

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