Gas thermal desorption flue gas serial flow reinjection energy-saving equipment and its use method

Abstract

The present invention provides a gas thermal desorption flue gas serial flow reinjection energy-saving device and a method for using the same, which relates to the technical field of contaminated soil remediation and pesticide site odor removal, and solves the technical problems of low energy utilization and limited energy-saving effect of existing gas thermal desorption remediation systems for contaminated soil. The gas thermal desorption flue gas serial flow reinjection energy-saving device includes a combustion system and a soil heating system; the combustion system includes a combustion chamber and a diverter device, the diverter device includes at least two airflow outlets arranged in parallel; the soil heating system includes a series pipe assembly and at least two groups of heating tube assemblies, the airflow inlet of each group of heating tube assemblies is respectively connected to the airflow outlet of the diverter device, and each airflow outlet of the diverter device is respectively provided with an on-off valve in front; at least two groups of heating tube assemblies can be connected through the series pipe assembly. The present invention is used to provide a gas thermal desorption flue gas serial flow reinjection energy-saving device with high heat utilization and low energy consumption and a method for using the same.

Description

Technical Field

[0001] The present invention relates to the technical field of contaminated soil remediation equipment, and in particular to a fuel gas thermal desorption flue gas serial flow reinjection energy-saving equipment and a method for using the same. Background Art

[0002] The in-situ thermal desorption technology of gas for remediation of organically contaminated soil and removal of odorous substances can be divided into two processes: thermal desorption and extraction. During soil remediation and odor removal, natural gas and clean air are introduced into the burner, where they are mixed and ignited to produce high-temperature gas. The high-temperature gas is injected into the heating well and allowed to flow back and forth within the well. The high-temperature gas indirectly heats the soil, heating the target remediation area through heat conduction, raising the soil temperature to the target temperature. During the heating process, pollutants and odorous substances in the soil are desorbed from the soil, forming pollutant-containing vapor. At this time, gas phase extraction is used to extract the vapor containing pollutants and odorous substances to the surface, and then enters the subsequent exhaust gas treatment equipment for further treatment to meet emission standards.

[0003] Due to the limited indirect heat exchange efficiency between the high-temperature flue gas in the heating tubes and the surrounding soil, the flue gas is still discharged at a relatively high temperature, resulting in high exhaust heat loss and high energy consumption. Published patents, such as the Chinese invention application with publication number CN109351766 A, provide an in-situ thermal desorption system for contaminated soil gas remediation. This system connects two heating wells in series, directing the high-temperature exhaust gas into the next heating well to heat the surrounding soil, thereby reducing exhaust heat loss and process energy consumption.

[0004] The applicant has discovered that in the prior art in-situ thermal desorption remediation system for contaminated soil gas, the heat of the high-temperature flue gas exhausted from the first heating well is limited, generally about 30%-40% of the input heat. This heat is insufficient to raise the soil temperature around the second heating well to the target temperature. In order to raise the soil temperature around the second heating well to the target temperature, high-temperature flue gas must be continuously supplied, which not only easily overheats the soil around the first heating well, but also increases the heat loss of the exhaust gas. If the heating effect of this method is improved by reducing the spacing between the heating wells or adding auxiliary heating devices, it will increase construction and energy costs. Summary of the Invention

[0005] The present invention aims to provide an energy-saving device for thermal desorption of gas and flue gas with serial flow reinjection, and its use method, to address the technical issues of low energy utilization and limited energy conservation in existing in-situ thermal desorption systems for contaminated soil. The various technical effects of the preferred technical solutions of the present invention are detailed below.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] The energy-saving equipment for thermal desorption of gas and flue gas serial flow reinjection provided by the present invention comprises a combustion system and a soil heating system; wherein,

[0008] The combustion system includes a combustion chamber and a diverter device, wherein the air flow inlet of the diverter device is connected to the air flow outlet of the combustion chamber, and the diverter device includes at least two air flow outlets arranged in parallel; the soil heating system includes a pipe assembly and at least two groups of heating tube assemblies, wherein the air flow inlet of each group of heating tube assemblies is respectively connected to the air flow outlet of the diverter device, and each air flow outlet of the diverter device is respectively provided with an on-off valve in front, so that the smoke flowing out of the air flow outlet end of the combustion chamber can enter at least one of the heating tube assemblies;

[0009] At least two groups of the heating tube assemblies can be connected through the pipe string assembly, and after the flue gas flows into one of the heating tube assemblies, it can enter the remaining heating tube assemblies through the pipe string assembly.

[0010] In a preferred or optional embodiment, each group of the heating tube assemblies includes an inner tube and an outer tube, the outer tube is sleeved outside the inner tube, the inner tube is connected to the air flow outlet of the diverter device, and the outer tube is closed at one end close to the diverter device; there is a gap between the inner tube and the outer tube to form a reflux channel, and the string tube assembly can connect the reflux channels in two adjacent groups of the heating tube assemblies.

[0011] In a preferred or optional embodiment, the string pipe assembly includes two connecting pipes and a one-way valve, and the two ends of each connecting pipe are respectively connected to the return channel of one of the two adjacent groups of heating pipe assemblies and the inner pipe of the other one thereof; one end of each connecting pipe is provided with the one-way valve, and the directions of the one-way valves installed on different connecting pipes are opposite.

[0012] In a preferred or optional embodiment, the soil heating system further comprises at least two smoke exhaust systems, each of which is respectively connected to a return flow channel in a group of the heating tube assemblies and can provide negative pressure into the return flow channel.

[0013] In a preferred or optional embodiment, the smoke exhaust system includes a smoke exhaust pipe and a smoke solenoid valve, one end of each of the smoke exhaust pipes is respectively connected to a return channel in a group of the heating tube assemblies, and the other end of each of the smoke exhaust pipes is connected to a fan.

[0014] In a preferred or optional embodiment, the combustion system further includes a secondary combustion-supporting air inlet pipe and an air inlet regulating valve arranged thereon, and the secondary combustion-supporting air inlet pipe is communicated with the combustion chamber.

[0015] In a preferred or optional embodiment, the combustion system further includes an exhaust gas reburning intake pipe and an exhaust gas solenoid valve arranged thereon, and the exhaust gas reburning intake pipe is connected to the combustion chamber.

[0016] In a preferred or optional embodiment, the combustion system further includes an air intake pipe, a gas intake pipe and a burner, the air intake pipe and the gas intake pipe are both communicable with the combustion chamber, and the combustion head of the burner extends into the combustion chamber.

[0017] In a preferred or optional embodiment, the smoke exhaust system also includes a smoke exhaust pipe and a smoke solenoid valve, and the gas thermal desorption and smoke flow reinjection energy-saving equipment also includes a temperature sensor and a central control device, and the central control device is electrically connected to the on-off valve, the smoke solenoid valve and the temperature sensor respectively.

[0018] A method for using a fuel gas thermal desorption and flue gas serial flow reinjection energy-saving device as provided by any technical solution of the present invention comprises the following steps:

[0019] Step A: Dig heating wells and dig temperature monitoring wells 0.2-0.3 meters next to each heating well and in the center of the three heating wells;

[0020] Step B: Place sections of the inner and outer pipes into the heating wells and place temperature sensors in each temperature monitoring well; simultaneously, set up an insulation layer under the ground so that the string pipe assembly is located within the insulation layer;

[0021] Step C: Turning on the burner, the on-off valve connected to one of the heating tube assemblies, and the flue gas solenoid valve connected to the other heating tube assembly to heat the soil around one of the heating wells and simultaneously heat the soil around the other heating well;

[0022] Step D: Based on the temperature difference detected by the temperature sensor in the different temperature monitoring wells, the on-off valve and the flue gas solenoid valve opened in step C are closed, and the on-off valve connected to the other heating tube assembly and the flue gas solenoid valve connected to one of the heating tube assemblies are opened to heat the soil around the other heating well and the soil around one of the heating wells at the same time;

[0023] Step E: Turn on the burner, the on-off valve connected to each heating tube assembly, and the flue gas solenoid valve connected to each heating tube assembly to heat the soil around the two heating wells simultaneously;

[0024] Step F: After the repair is completed, turn off the burner and remove the equipment;

[0025] Among them, step C and step D are one working mode of the said gas thermal desorption flue gas serial flow reinjection energy-saving equipment, and step E is another working mode of the said gas thermal desorption flue gas serial flow reinjection energy-saving equipment.

[0026] The gas thermal desorption flue gas serial flow reinjection energy-saving equipment provided by the present invention comprises a combustion system and a soil heating system, wherein the combustion system is provided with at least two air flow outlets in parallel, each of the air flow outlets is connected to a heating pipe assembly, and an on-off valve is provided at the front of each air flow outlet; at least two of the heating pipe assemblies can be connected through the serial pipe assembly; when the equipment is running, only one of the on-off valves is opened to allow the flue gas in the combustion chamber to enter one of the heating pipe assemblies, thereby heating the soil around one of the heating pipe assemblies, and the flue gas with residual heat then flows into the other heating pipe assembly through the serial pipe assembly. The heat pipe assembly heats the soil around the other heating pipe assembly; when the temperature difference between the two heating wells is greater than the set value, one of the on-off valves is closed and the other on-off valve is opened, so that the flue gas in the combustion chamber first flows into the other heating pipe assembly. Since the other heating pipe assembly has been heated by utilizing the waste heat, the energy required for further heating is relatively low at this time. At the same time, one of the heating wells can also be continuously heated to reach the target heating temperature. While further utilizing the waste heat of the flue gas, the heating effect of the soil at different positions is guaranteed, effectively saving operating energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 A schematic structural diagram of a fuel gas thermal desorption and flue gas serial flow reinjection energy-saving device provided by the present invention from one perspective;

[0029] Figure 2 This is a schematic structural diagram from another perspective of the fuel gas thermal desorption and flue gas serial flow reinjection energy-saving equipment provided by the present invention;

[0030] Figure 3 This is a schematic diagram of the distribution of heating wells, extraction wells, and temperature monitoring wells provided by the present invention.

[0031] In the figure, 1. Combustion system; 11. Combustion chamber; 12. Diverter device; 121. On-off valve; 13. Secondary combustion air inlet pipe; 131. Air inlet regulating valve; 14. Exhaust backfire air inlet pipe; 141. Exhaust solenoid valve; 15. Air inlet pipe; 16. Gas inlet pipe; 17. Burner; 171. Combustion head; 18. Cabinet; 181. Ignition / stop button; 182. Reset button; 183. Indicator light; 2. Soil heating system; 21. Serial pipe assembly; 211. Connecting pipe; 212. One-way valve; 22. Heating pipe assembly; 221. Inner pipe; 222. Outer pipe; 223. Backflow channel; 3. Smoke exhaust system; 31. Smoke exhaust pipe; 32. Smoke solenoid valve; 4. Temperature sensor; 5. Central control device; 6. Heating well; 7. Temperature monitoring well; 8. Extraction well; 9. Insulation layer; 10. Concrete hardened ground. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0033] The present invention provides a gas thermal desorption flue gas serial flow reinjection energy-saving device and a method for using the same, which can improve the heat utilization rate in the gas thermal desorption device and save operating energy consumption.

[0034] The following combination Figures 1 to 3 The technical solution provided by the present invention is described in more detail.

[0035] like Figures 1 to 3 As shown, the energy-saving equipment for thermal desorption of gas and flue gas serial flow reinjection provided by the present invention comprises a combustion system 1 and a soil heating system 2; wherein,

[0036] The combustion system 1 includes a combustion chamber 11 and a diverter 12. The air flow inlet of the diverter 12 is connected to the air flow outlet of the combustion chamber 11. The diverter 12 includes at least two air flow outlets arranged in parallel. The soil heating system 2 includes a pipe assembly 21 and at least two groups of heating tube assemblies 22. The air flow inlet of each group of heating tube assemblies 22 is respectively connected to the air flow outlet of the diverter 12. The front of each air flow outlet of the diverter 12 is respectively provided with an on-off valve 121, which can allow the flue gas flowing out of the air flow outlet end of the combustion chamber 11 to enter at least one of the heating tube assemblies 22.

[0037] At least two groups of heating tube assemblies 22 can be connected through the pipe string assembly 21 . After the flue gas flows into one of the heating tube assemblies 22 , it can enter the remaining heating tube assemblies 22 through the pipe string assembly 21 .

[0038] The gas thermal desorption flue gas serial flow reinjection energy-saving equipment provided by the present invention includes a combustion system 1 and a soil heating system 2. The combustion system 1 is provided with at least two air flow outlets in parallel, each of which is connected to a heating pipe assembly 22, and a shutoff valve 121 is provided in front of each air flow outlet; at least two heating pipe assemblies 22 can be connected through the serial pipe assembly 21; when the equipment is running, only one of the on-off valves 121 is opened to allow the flue gas in the combustion chamber 11 to enter one of the heating pipe assemblies 22, to heat the soil around one of the heating pipe assemblies 22, and the flue gas with residual heat then flows into the other through the serial pipe assembly 21. The heating tube assembly 22 heats the soil surrounding the other heating tube assembly 22. When the temperature difference between the two heating wells 6 is greater than a set value, one of the on-off valves 121 is closed and the other on-off valve 121 is opened, allowing the flue gas in the combustion chamber 11 to flow into the other heating tube assembly 22 first. Since the other heating tube assembly 22 has been heated by waste heat, the energy required for further heating is relatively low. At the same time, one of the heating wells 6 can continue to be heated to reach the target heating temperature. While further utilizing the waste heat of the flue gas, the heating effect of each soil is guaranteed, effectively saving operating energy consumption. Specifically, the on-off valve 121 can be a solenoid valve, a manual regulating valve, etc., and its main purpose is to control the on-off of different airflow outlets of the diversion device 12.

[0039] As a preferred or optional embodiment, each group of heating tube assemblies 22 includes an inner tube 221 and an outer tube 222. The outer tube 222 is sleeved on the outside of the inner tube 221. The inner tube 221 is connected to the air flow outlet of the diversion device 12, and the outer tube 222 is closed at one end close to the diversion device 12. There is a gap between the inner tube 221 and the outer tube 222 to form a return channel 223. The string tube assembly 21 can connect the return channels 223 in two adjacent groups of heating tube assemblies 22.

[0040] Specifically, when the equipment is running, the high-temperature flue gas in the combustion chamber 11 enters the bottom of the heating well 6 through one of the inner tubes 221 and then flows back into the reflux channel 223. At this time, the high-temperature flue gas exchanges heat with the outer tube 222, and the outer tube 222 exchanges heat with the external soil, thereby achieving indirect heating of the soil; the flue gas flowing back into the reflux channel 223 can enter the reflux channel 223 in another heating tube assembly 22 through the string pipe assembly 21, thereby preheating the soil near the other heating well 6.

[0041] As a preferred or optional embodiment, the string pipe assembly 21 includes two connecting pipes 211 and a one-way valve 212, and the two ends of each connecting pipe 211 are respectively connected to the return channel 223 of one of the two adjacent groups of heating pipe assemblies 22 and the inner tube 221 of the other one thereof; a one-way valve 212 is provided at one end of each connecting pipe 211, and the directions of the one-way valves 212 installed on different connecting pipes 211 are opposite.

[0042] Specifically, since the on-off valve 121 can alternately open and close the airflow outlet of the diversion device 12, the flow direction of the high-temperature flue gas between the two groups of heating tube assemblies 22 is alternately changed. Two connecting pipes 211 are set and a one-way valve 212 with different directions is installed at the mouth of each connecting pipe 211 to prevent the high-temperature flue gas from circulating in the opposite direction; the flue gas in the reflux channel 223 of one of the heating tube assemblies 22 enters the inner tube 221 of the other heating tube assembly 22 through one of the connecting pipes 211, and then flows back from the bottom of the inner tube 221 to the reflux channel 223 of the other heating tube assembly 22.

[0043] As a preferred or optional embodiment, the soil heating system 2 further includes at least two smoke exhaust systems 3 , each of which is respectively connected to a return channel 223 in a group of heating tube assemblies 22 and can provide negative pressure into the return channel 223 .

[0044] As a preferred or optional embodiment, the smoke exhaust system 3 also includes a smoke exhaust pipe 31 and a smoke solenoid valve 32. The smoke exhaust system 3 includes a smoke exhaust pipe 31 and a smoke solenoid valve 32. One end of each smoke exhaust pipe 31 is respectively connected to the return channel 223 in a group of heating tube assemblies 22, and the other end of each smoke exhaust pipe 31 is connected to the fan.

[0045] Specifically, when the equipment is running, the on-off valve 121 on one side is opened, and the flue gas solenoid valve 32 and the fan on the other side are opened at the same time. The smoke exhaust system 3 can provide negative pressure for the return channel 223, so that the high-temperature flue gas can first pass through the heating tube assembly 22 on one side, pass through the series pipe assembly 21, enter the heating tube assembly 22 on the other side, and finally be extracted by the smoke exhaust system 3 on the other side; by changing the on-off of the on-off valve 121, the flue gas solenoid valve 32 and the opening and closing of the fan, the flow direction of the high-temperature flue gas in the equipment can be controlled.

[0046] As a preferred or optional embodiment, the combustion system 1 further includes a secondary combustion-supporting air inlet pipe 13 and an air inlet regulating valve 131 provided thereon, and the secondary combustion-supporting air inlet pipe 13 is communicated with the combustion chamber 11 .

[0047] Specifically, when the amount of air is insufficient, the air inlet regulating valve 131 can be manually adjusted to open the secondary combustion-supporting air inlet pipe 13 to supplement the amount of air and make the fuel burn more fully.

[0048] As a preferred or optional embodiment, the combustion system 1 further includes an exhaust gas backfire intake pipe 14 and an exhaust gas solenoid valve 141 arranged thereon, and the exhaust gas backfire intake pipe 14 is connected to the combustion chamber 11.

[0049] Specifically, an extraction well 8 is generally provided at a soil contamination treatment site. After the soil is heated by the heating well 6, the steam generated by the heating of the soil pore water carries pollutants and is extracted from the extraction well 8. The steam carrying organic pollutants is collectively referred to as extraction tail gas. The extracted tail gas cannot be discharged directly after being extracted and needs to be treated before it can be discharged. The present invention provides an exhaust backfire inlet pipe 14, which is connected to the extraction well 8, and passes the extracted tail gas into the combustion chamber 11 for combustion or high-temperature treatment, so that the pollutants in the tail gas are burned or decomposed by high-temperature treatment to meet the safety emission standards, alleviate the operating pressure of the tail gas treatment equipment, and reduce the energy consumption of the remediation process.

[0050] As a preferred or optional embodiment, the combustion system 1 also includes an air intake pipe 15, a gas intake pipe 16 and a burner 17. The air intake pipe 15 and the gas intake pipe 16 can both be connected to the combustion chamber 11, and the combustion head 171 of the burner 17 extends into the combustion chamber 11.

[0051] Specifically, air and gas enter the combustion chamber 11 through the air intake pipe 15 and the gas intake pipe 16 respectively and are mixed, and the combustion head 171 of the burner 17 ignites the mixed gas and burns it.

[0052] Specifically, the burner 17 is also connected to a cabinet 18, on which an ignition / stop button 181, a reset button 182 and an indicator light 183 are provided. The ignition / stop button 181, the reset button 182 and the indicator light 183 are all electrically connected to the burner 17 respectively; the ignition / stop button 181 is used to control the ignition and stop of the burner, the reset button 182 is used to reset after a fault occurs on site to solve the problem, and the indicator light 183 is used to display the operation, stop and fault status of the equipment.

[0053] As a preferred or optional embodiment, the gas thermal desorption flue gas serial flow reinjection energy-saving equipment also includes a temperature sensor 4 and a central control device 5, and the central control device 5 is electrically connected to the on-off valve 121, the flue gas solenoid valve 32 and the temperature sensor 4 respectively.

[0054] Specifically, during the operation of the equipment, high-temperature flue gas flows in from one of the heating wells 6, passes through the string pipe assembly 21, and is discharged from the exhaust system of the other heating well, so that the temperature of the first heating well 6 is higher than that of the other heating well 6, and the surrounding soil also shows the same trend. The soil temperature around the two heating wells can be measured by the temperature sensor 4 in the temperature monitoring well 7 and transmitted to the central control device 5. The central control device 5 receives the temperature difference data of the two temperature monitoring wells 7. The staff can manually switch the on-off valve 121 and the flue gas solenoid valve 32 to adjust the flue gas flow direction; or, the temperature difference value of the two temperature monitoring wells 7 can be set in the central control device 5. When the temperature difference is greater than the set value, the on-off valve 121 and the flue gas solenoid valve 32 are automatically switched to adjust the flue gas flow direction.

[0055] Specifically, a heat-insulating sleeve is provided outside the combustion chamber 11, which can not only prevent on-site workers from being scalded, but also reduce heat dissipation from the pipe wall and reduce heat loss.

[0056] A method for using a fuel gas thermal desorption and flue gas serial flow reinjection energy-saving device as provided by any technical solution of the present invention comprises the following steps:

[0057] Step A: Dig heating wells 6, and dig temperature monitoring wells 7 at 0.2-0.3 meters next to each heating well 6 and at the center of the three heating wells 6;

[0058] Step B: Place sections of the inner tube 221 and the outer tube 222 into the heating well 6, and place a temperature sensor 4 into each temperature monitoring well 7. One or more temperature sensors 4 may be placed in each temperature monitoring well 7 according to the well depth, and the multiple temperature sensors 4 are evenly distributed along the depth direction of the temperature monitoring well 7. Simultaneously, an insulation layer 9 is provided under the hardened concrete floor 10, with the string pipe assembly 21 located within the insulation layer 9.

[0059] Step C: Turn on the burner 17, the on-off valve 121 connected to one of the heating tube assemblies 22, and the flue gas solenoid valve 32 connected to the other heating tube assembly 22 to heat the soil around one of the heating wells 6 and simultaneously heat the soil around the other heating well 6;

[0060] Step D: Based on the temperature difference detected by the temperature sensor 4 in the different temperature monitoring wells 7, the on-off valve 121 and the flue gas solenoid valve 32 opened in step C are closed, and the on-off valve 121 connected to the other heating tube assembly 22 and the flue gas solenoid valve 32 connected to one of the heating tube assemblies 22 are opened to heat the soil around the other heating well 6 and the soil around one of the heating wells 6 at the same time;

[0061] Step E: Turn on the burner, the on-off valve connected to each heating tube assembly, and the flue gas solenoid valve connected to each heating tube assembly to heat the soil around the two heating wells simultaneously;

[0062] Step F: After the repair is completed, turn off the burner 17 and remove the equipment;

[0063] Among them, step C and step D are another working mode of the gas thermal desorption flue gas serial flow reinjection energy-saving device, and step E is another working mode of the gas thermal desorption flue gas serial flow reinjection energy-saving device

[0064] Specifically, the above steps C and D can achieve energy-saving effects by periodically switching the on-off valve 121; step E opens each on-off valve 121. Although the energy-saving effect is slightly worse, for repair projects with tight schedules, the method of step E, on the one hand, saves burner costs compared to the method of installing a burner in each heating well 6, and on the other hand, there is no need to set a string pipe assembly 21 between the heating wells 6, which has a simple structure and a short processing cycle.

[0065] From the perspective of energy flow, by periodically switching the on-off valve 121, the total energy output by the two heating wells 6 is the same, and in different cycles, the heat released outward by each heating well 6 that is the first to enter the flue gas is the same, and the heat released outward by each heating well 6 that is the last to enter the flue gas is also the same, which can make the two heating wells rise to the target temperature at a more balanced temperature.

[0066] Specifically, the remediation site is generally large in area, and the number of heating wells 6 used is also large. The heating wells 6 are often arranged in a triangular pattern, and each row is arranged in parallel. Figure 3 When using the flue gas serial reinjection technology of the present invention with parallel heating wells 6 for gas thermal desorption, the series connection of all heating wells 6 must be designed, typically in an upper and lower series arrangement. During operation, the operation of the on-off valve 121 and the smoke exhaust system 3 is determined by the spacing, i.e., the first row is the smoke inlet, the second row is the outlet, the third row is the smoke inlet, the fourth row is the smoke outlet, and so on. This can reduce the temperature difference in the remediation site. In addition, since the temperature rise trend of the site is the same, the number of temperature monitoring wells can be reduced, and only one or two groups of temperature monitoring wells can be set up in one block.

[0067] Unless otherwise stated, for any of the technical solutions disclosed in the present invention, if a numerical range is disclosed, the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is merely a numerical range that is representative or has a more obvious technical effect among many feasible numerical values. Due to the large number of numerical values, it is impossible to enumerate them exhaustively. Therefore, the present invention discloses some numerical values ​​to illustrate the technical solutions of the present invention. Moreover, the numerical values ​​listed above should not be construed as limiting the scope of protection of the present invention.

[0068] If words such as "first" and "second" are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of description to distinguish between components. Unless otherwise stated, the above words have no special meaning.

[0069] At the same time, if the above-mentioned invention discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be an integrated structure (for example, one-piece molding using a casting process) (except where it is obviously impossible to use an integrated molding process).

[0070] In addition, unless otherwise stated, terms used in any of the technical solutions disclosed herein to represent positional relationships or shapes include states or shapes that are similar, analogous, or approximate. Any component provided by the present invention may be assembled from multiple separate components or may be a single component manufactured using an integral molding process.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solutions of the present invention. They should all be included in the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A fuel gas thermal desorption flue gas serial flow reinjection energy-saving equipment, characterized in that: Including combustion system and soil heating system; The combustion system includes a combustion chamber and a diverter device, wherein the air flow inlet of the diverter device is connected to the air flow outlet of the combustion chamber, and the diverter device includes at least two air flow outlets arranged in parallel; the soil heating system includes a pipe assembly and at least two groups of heating tube assemblies, wherein the air flow inlet of each group of heating tube assemblies is respectively connected to the air flow outlet of the diverter device, and each air flow outlet of the diverter device is respectively provided with an on-off valve in front, so that the smoke flowing out of the air flow outlet end of the combustion chamber can enter at least one of the heating tube assemblies; At least two groups of the heating tube assemblies can be connected through the string tube assembly, and after the flue gas flows into one of the heating tube assemblies, it can enter the other heating tube assemblies through the string tube assembly; each group of the heating tube assemblies includes an inner tube and an outer tube, the outer tube is sleeved outside the inner tube, the inner tube is connected to the air flow outlet of the diverter device, and the end of the outer tube close to the diverter device is closed; there is a gap between the inner tube and the outer tube to form a reflux channel, and the string tube assembly can connect the flue gas in the two adjacent groups of the heating tube assemblies The return channels are connected; the string pipe assembly includes two connecting pipes and a one-way valve, and both ends of each connecting pipe are respectively connected to the return channel of one of the two adjacent groups of heating pipe assemblies and the inner tube of the other one; one end of each connecting pipe is provided with the one-way valve, and the directions of the one-way valves installed on different connecting pipes are opposite; the soil heating system also includes at least two smoke exhaust systems, each of which is respectively connected to the return channel in one group of the heating pipe assemblies and can provide negative pressure into the return channel.

2. The fuel gas thermal desorption flue gas serial flow reinjection energy-saving equipment according to claim 1 is characterized in that: The smoke exhaust system includes a smoke exhaust pipe and a smoke solenoid valve. One end of each of the smoke exhaust pipes is connected to a return channel in a group of the heating tube assemblies, and the other end of each of the smoke exhaust pipes is connected to a fan.

3. The energy-saving equipment for thermal desorption of fuel gas and flue gas serial flow reinjection according to any one of claims 1-2, characterized in that: The combustion system further comprises a secondary combustion-supporting air inlet pipe and an air inlet regulating valve arranged thereon, and the secondary combustion-supporting air inlet pipe is communicated with the combustion chamber.

4. The fuel gas thermal desorption flue gas serial flow reinjection energy-saving equipment according to claim 3 is characterized in that: The combustion system further includes an exhaust gas re-entry intake pipe and an exhaust gas solenoid valve arranged thereon, and the exhaust gas re-entry intake pipe is communicated with the combustion chamber.

5. The fuel gas thermal desorption flue gas serial flow reinjection energy-saving equipment according to claim 3 is characterized in that: The combustion system further comprises an air intake pipe, a gas intake pipe and a burner. The air intake pipe and the gas intake pipe are both in communication with the combustion chamber, and the combustion head of the burner extends into the combustion chamber.

6. The fuel gas thermal desorption and flue gas serial flow reinjection energy-saving equipment according to claim 5 is characterized in that: The soil heating system also includes at least two smoke exhaust systems, each of which includes a smoke exhaust pipe and a smoke solenoid valve. The gas thermal desorption smoke flow reinjection energy-saving equipment also includes a temperature sensor and a central control device, and the central control device is electrically connected to the on-off valve, the smoke solenoid valve and the temperature sensor respectively.

7. A method for using the fuel gas thermal desorption and flue gas serial flow reinjection energy-saving device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step A: Dig heating wells and dig temperature monitoring wells 0.2-0.3 meters next to each heating well and in the center of the three heating wells; Step B: Place sections of the inner and outer pipes into the heating wells and place temperature sensors in each temperature monitoring well; simultaneously, set up an insulation layer under the ground so that the string pipe assembly is located within the insulation layer; Step C: Turning on the burner, the on-off valve connected to one of the heating tube assemblies, and the flue gas solenoid valve connected to the other heating tube assembly to heat the soil around one of the heating wells and simultaneously heat the soil around the other heating well; Step D: Based on the temperature difference detected by the temperature sensor in the different temperature monitoring wells, the on-off valve and the flue gas solenoid valve opened in step C are closed, and the on-off valve connected to the other heating tube assembly and the flue gas solenoid valve connected to one of the heating tube assemblies are opened to heat the soil around the other heating well and the soil around one of the heating wells at the same time; Step E: Turn on the burner, the on-off valve connected to each heating tube assembly, and the flue gas solenoid valve connected to each heating tube assembly to heat the soil around the two heating wells simultaneously; Step F: After the repair is completed, turn off the burner and remove the equipment; Among them, step C and step D are one working mode of the said gas thermal desorption flue gas serial flow reinjection energy-saving equipment, and step E is another working mode of the said gas thermal desorption flue gas serial flow reinjection energy-saving equipment.

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