Method and device for increasing the temperature of coal gas by self-induced combustion

Abstract

The application discloses a method and device for improving coal gas temperature by self-extraction of gas combustion, which comprises the following steps: firstly, low-pressure and low-temperature coal gas is extracted from the upstream of a main coal gas pipe; then, the extracted coal gas is combusted with air in an excess state at a micro-positive pressure to generate micro-positive pressure and high-temperature flue gas and to buffer; then, the high-pressure inert gas is used to induce the micro-positive pressure and high-temperature flue gas to form high-temperature flue gas mixed gas with a pressure value higher than that of the upstream coal gas of the main coal gas pipe; finally, the high-temperature flue gas mixed gas is merged into the downstream of the main coal gas pipe and is fully mixed with the low-pressure and low-temperature coal gas from the upstream to form high-temperature coal gas. The application has low cost, can improve the coal gas temperature, eliminate the influence of coal gas condensation on the downstream system, meet the required working condition temperature requirement of the downstream process, and is safe and reliable.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coal gas production, and particularly relates to a method and device for improving the temperature of coal gas through self-extraction gas combustion. BACKGROUND

[0002] The coal gas system in industrial enterprises generally adopts low-temperature operation, and contains a large amount of mechanical water and saturated water. When the coal gas dry dedusting and condensate water acid corrosion are involved, the normal operation of the coal gas system is adversely affected, and even the normal and stable operation of the coal gas system is affected. Although the operation stability and reliability of the coal gas system will be greatly increased when the temperature of the coal gas is appropriately increased to above the dew point, the scheme for increasing the temperature of the coal gas is difficult to implement due to the large amount of coal gas generation and the low-pressure operation. SUMMARY

[0003] The purpose of the present application is to provide a method and device for improving the temperature of coal gas through self-extraction gas combustion. The present application has low cost, can improve the temperature of coal gas, eliminate the influence of coal gas condensation on the downstream system, and achieve the required operating temperature requirement of the downstream process, and is safe and reliable.

[0004] The technical scheme adopted by the present application is as follows:

[0005] A method for improving the temperature of coal gas through self-extraction gas combustion, low-pressure and low-temperature coal gas is first extracted from the upstream of the coal gas main pipe, and then the extracted coal gas is combusted with air in an excess state at a slight positive pressure to generate slight positive pressure and high temperature flue gas, and then the high pressure inert gas is used to inject the slight positive pressure and high temperature flue gas to form high temperature flue gas mixed gas with a pressure value higher than that of the coal gas upstream of the coal gas main pipe, and finally the high temperature flue gas mixed gas is merged into the downstream of the coal gas main pipe and fully mixed with the low-pressure and low-temperature coal gas from the upstream to form high temperature coal gas.

[0006] Further, the required coal gas temperature or dew point temperature is used as a set value, the temperature of the high temperature coal gas is detected in real time, and the extraction amount of the coal gas is controlled to make the detected value and the set value tend to be the same through comparison.

[0007] Further, the high pressure inert gas is high pressure nitrogen.

[0008] A device for improving the temperature of coal gas through self-extraction gas combustion, comprising a burner for the slight positive pressure combustion of air and excess coal gas, the coal gas inlet of the burner is connected to the upstream of the coal gas main pipe through an extraction pipe, the flue gas outlet is connected to a flue gas tank for buffering and an ejector for pressure boosting in sequence through a pipeline, the injection gas inlet of the ejector is connected to high pressure inert gas through an injection gas pipe, and the pressure boosting outlet is connected to the inlet end of a mixer located downstream of the coal gas main pipe through a backflow pipe.

[0009] Further, the mixer outlet end is provided with a temperature detecting element, and the suction pipe is provided with a flow regulating valve, taking the required coal gas temperature or dew point temperature as the set value, the flow regulating valve automatically adjusts the opening degree according to the set value and the detection value fed back by the temperature detecting element, the opening degree of the flow regulating valve increases when the detection value is less than the set value, the opening degree of the flow regulating valve does not change when the detection value reaches the set value, and the opening degree of the flow regulating valve decreases when the detection value is greater than the set value.

[0010] Further, the suction pipe and the injection pipe are both provided with electrically-controlled cut-off valves, and the electrically-controlled cut-off valves on the suction pipe and the injection pipe are synchronously operated.

[0011] Further, the smoke tank is connected with a discharge pipe provided with a valve.

[0012] Further, the backflow pipe is provided with a check valve.

[0013] Further, the high-pressure inert gas is high-pressure nitrogen.

[0014] Further, the body of the smoke tank and the inlet and outlet connecting pipes are both subjected to heat insulation treatment.

[0015] The present application has the following advantages:

[0016] The present application has the following advantages: BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic view of the device for improving the coal gas temperature by self-suction gas combustion in the embodiment of the present application.

[0018] In the figure, 1 is a coal gas main pipe, 2 is a suction pipe, 3 is an electrically-controlled cut-off valve, 4 is a flow regulating valve, 5 is an injection pipe, 6 is an injector, 7 is a backflow pipe, 8 is a check valve, 9 is a valve, 10 is a discharge pipe, and 11 is a temperature detecting element. DETAILED DESCRIPTION

[0019] The present application will be further described below in combination with the drawings and embodiments.

[0020] A method for increasing the temperature of coal gas by self-extraction combustion, low-pressure and low-temperature coal gas is first extracted from the upstream of a main coal gas pipe 1, and then the extracted coal gas is combusted with air in an excess state at a slight positive pressure to generate high-temperature flue gas at a slight positive pressure and to buffer, and then the high-temperature flue gas at a slight positive pressure is injected by using high-pressure inert gas to form high-temperature flue gas mixture with a pressure value higher than that of the coal gas upstream of the main coal gas pipe 1 (in the process of injection, the temperature of the flue gas slightly decreases, but is still at a relatively high level), and finally the high-temperature flue gas mixture is merged into the downstream of the main coal gas pipe 1 and is fully mixed with the low-pressure and low-temperature coal gas from the upstream to form high-temperature coal gas; the temperature of the high-temperature coal gas is detected in real time by taking the required coal gas temperature or dew point temperature as a set value, and the extraction amount of the coal gas is controlled by comparing the detected value and the set value to make them tend to be the same; the high-pressure inert gas is high-pressure nitrogen.

[0021] As shown in Figure 1 , a device for increasing the temperature of coal gas by self-extraction combustion, comprising a combustor for combusting air and excess coal gas at a slight positive pressure, a coal gas inlet of the combustor being connected to the upstream of a main coal gas pipe 1 through an extraction pipe 2, a flue gas outlet being connected in sequence to a flue gas tank for buffering and an ejector 6 for injection pressurization through a pipeline, an injection gas inlet of the ejector 6 being connected to high-pressure inert gas through an injection gas pipe 5, and a pressurized outlet being connected to an inlet end of a mixer located downstream of the main coal gas pipe 1 through a backflow pipe 7.

[0022] As shown in Figure 1 , in this embodiment, a temperature detection element 11 is arranged at an outlet end of the mixer, and a flow regulating valve 4 is arranged on the extraction pipe 2, and the required coal gas temperature or dew point temperature is taken as a set value, the flow regulating valve 4 automatically adjusts the opening degree according to the set value and the detected value fed back by the temperature detection element 11, the opening degree of the flow regulating valve 4 increases when the detected value is less than the set value, the opening degree of the flow regulating valve 4 does not change when the detected value reaches the set value, and the opening degree of the flow regulating valve 4 decreases when the detected value is greater than the set value. Due to the fact that there are deviations in design parameters and the like in the actual operation process of the coal gas system, there are unavoidable pressure and component fluctuations, and the flue gas temperature may change accordingly, in order to ensure the stability and reliability of the system, the flow regulating valve 4 and the temperature detection element 11 are matched to maintain the coal gas temperature at the set value.

[0023] As shown in Figure 1 , in this embodiment, electrically-controlled cut-off valves 3 are arranged on the extraction pipe 2 and the injection gas pipe 5, and the electrically-controlled cut-off valves 3 on the extraction pipe 2 and the injection gas pipe 5 are synchronously operated to ensure the stability and safety of the system.

[0024] As shown in Figure 1 , in this embodiment, the flue gas tank is connected with a discharge pipe 10 provided with a valve 9, the valve 9 is closed under normal conditions, and the valve 9 is opened when system accidents or emergency shutdowns occur, and part of the flue gas generated by combustion is discharged to the outside through the discharge pipe 10.

[0025] AsFigure 1 As shown in the embodiment, the backflow pipe 7 is provided with a check valve 8 to ensure that the gas does not flow backward in the system maintenance or accident state.

[0026] In the embodiment, high-pressure inert gas is high-pressure nitrogen, which can ensure the safety of the system and control the entrainment ratio at a high level so as to not excessively reduce the flue gas temperature.

[0027] In the embodiment, the body of the flue gas tank and the inlet and outlet connecting pipes are all heat-insulated, and the volume of the flue gas tank is determined according to the system gas amount.

[0028] As shown in the embodiment, the backflow pipe 7 is provided with a check valve 8 to ensure that the gas does not flow backward in the system maintenance or accident state. Figure 1 As shown in the embodiment, the backflow pipe 7 is provided with a check valve 8 to ensure that the gas does not flow backward in the system maintenance or accident state.

[0029] In the embodiment, the ejector 6 is connected in series according to the need for pressure increase.

[0030] The present application has small consumption of gas and external high-pressure entraining gas and low cost, can improve the gas temperature, eliminate the influence of gas condensation on the downstream system, meet the required working condition temperature of the downstream process, avoid the safety hazard of the system caused by the excessive oxygen concentration in the flue gas generated by gas combustion, and is safe and reliable.

[0031] It should be understood that the above description can be improved or changed by those skilled in the art, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A method for increasing the temperature of coal gas through self-extraction combustion, characterized in that: First, low-pressure, low-temperature coal gas is extracted from the upstream of the main gas pipe. Then, the extracted coal gas is burned with air in an excess state under slight positive pressure to generate slightly positive pressure high-temperature flue gas and buffer it. Then, high-pressure inert gas is used to entice the slightly positive pressure high-temperature flue gas to form a high-temperature flue gas mixture with a pressure value higher than that of the coal gas upstream of the main gas pipe. Finally, the high-temperature flue gas mixture is merged into the downstream of the main gas pipe and fully mixed with the low-pressure, low-temperature coal gas from the upstream to form high-temperature coal gas.

2. The method for increasing coal gas temperature through self-extraction combustion as described in claim 1, characterized in that: The required gas temperature or dew point temperature is used as the set value. The temperature of high-temperature gas is detected in real time. The gas extraction rate is controlled by comparing the detected value and the set value to make the two converge.

3. The method for increasing coal gas temperature through self-extraction combustion as described in claim 1, characterized in that: High-pressure inert gas is high-pressure nitrogen.

4. A device for increasing the temperature of coal gas through self-extraction combustion, characterized in that: It includes a burner for micro-positive pressure combustion of air and excess gas. The gas inlet of the burner is connected to the upstream of the main gas pipe through an extraction pipe, and the flue gas outlet is connected in sequence to a flue gas tank for buffering and an ejector for ejector pressurization through a pipeline. The ejector gas inlet is connected to high-pressure inert gas through an ejector gas pipe, and the pressurization outlet is connected to the mixer inlet located downstream of the main gas pipe through a return pipe.

5. The device for increasing the temperature of coal gas through self-extraction combustion as described in claim 4, characterized in that: The mixer outlet is equipped with a temperature detection element, and the extraction pipe is equipped with a flow regulating valve. The required gas temperature or dew point temperature is used as the set value. The flow regulating valve automatically adjusts its opening based on the set value and the detection value fed back by the temperature detection element. When the detection value is less than the set value, the opening of the flow regulating valve increases. When the detection value reaches the set value, the opening of the flow regulating valve remains unchanged. When the detection value is greater than the set value, the opening of the flow regulating valve decreases.

6. The apparatus for increasing the temperature of coal gas through self-extraction combustion as described in claim 4, characterized in that: Both the extraction pipe and the ejector pipe are equipped with electrically controlled shut-off valves, which operate synchronously.

7. The apparatus for increasing the temperature of coal gas through self-extraction combustion as described in claim 4, characterized in that: The flue gas canister is connected to an exhaust pipe with a valve.

8. The apparatus for increasing the temperature of coal gas through self-extraction combustion as described in claim 4, characterized in that: A check valve is installed on the return pipe.

9. The apparatus for increasing the temperature of coal gas through self-extraction combustion as described in claim 4, characterized in that: High-pressure inert gas is high-pressure nitrogen.

10. The apparatus for increasing the temperature of coal gas through self-extraction combustion as described in claim 4, characterized in that: The main body of the flue gas canister and the inlet and outlet connecting pipes are all insulated.

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