LNG Emergency Gasification Device and Method

Abstract

The present invention relates to an LNG emergency gasification device and method. The device includes an air compressor, an electric heater, an attached reactor, an LNG-air heat exchanger, and a dual-functional heat exchange reactor. The dual-functional heat exchange reactor includes a reactor shell, a catalytic combustion reaction tube located inside the reactor shell, and a spiral LNG gasification coil located inside the reactor shell and surrounding the outer periphery of the catalytic combustion reaction tube. The reactor shell is provided with a flue gas outlet for discharging the flue gas in the inner cavity of the reactor shell. The present invention eliminates the explosion risk caused by flames in traditional devices; the combustion chamber temperature can be reduced to below 550°C, effectively suppressing the occurrence of the thermal effect NOx generation reaction; different from the flame combustion mode, flameless combustion allows a higher reaction pressure, thereby reducing the sizes of the burner and the heat exchange system and improving the device integration degree. In addition, the utilization of radiant heat is increased, and no heat exchange medium such as water is required.

Description

Technical Field

[0001] The present invention relates to an LNG emergency gasification device and method. Background Art

[0002] During the process of natural gas supply, emergency repair operations on natural gas pipelines often occur, or the gas supply capacity of the gasification station is insufficient during the peak period of natural gas consumption. At this time, an LNG emergency gas supply device is needed for regional emergency gas supply or supplementary gas supply, which can effectively avoid gas cut-off accidents and ensure the safe and continuous gas use of users.

[0003] LNG emergency gasification devices are generally applied to LNG gasification stations or densely populated urban areas. Once an explosion accident occurs, it will not only cause huge economic losses but also may lead to casualties. According to the current specifications in China, natural gas belongs to explosive gas, and its classification, grouping, and grading are: Class II - Grade A - Group T1. The explosion-proof grade of relevant storage, transportation, and treatment equipment should reach this level. Currently, the burners used in LNG emergency gasification devices on the domestic market are all traditional flame burners. Such burners are extremely likely to accumulate a large amount of high-concentration combustible gas in the furnace and be within the explosion limit due to improper ignition, unstable flame extinction, incomplete purging, etc. Then, when igniting again, it is possible to immediately explode when these combustible gases are ignited. Moreover, the environmental problem in natural gas combustion is that due to the high calorific value of natural gas, the combustion chamber temperature is as high as 1800°C, and the N2 in the combustion-supporting air undergoes high-temperature oxidation, causing NOx pollution. At the same time, such burners produce open flames, and the fire prevention distance from Class A process units and hydrocarbon storage tanks is required to be greater than 30 mm. However, the function of the mobile LNG emergency gasification device is to be used in the LNG gasification station or connected to the LNG storage tank to cope with scenarios such as urban gas peak shaving or temporary gas supply during the maintenance of industrial and civil gas facilities. It is difficult to meet the fire prevention distance requirements, which restricts the market promotion of such products.

[0004] Technical defects existing in the existing catalyst evaluation devices:

[0005] (1) Currently, the burners used in LNG emergency gasification devices on the domestic market are all traditional flame burners. Such burners are extremely likely to accumulate a large amount of high-concentration combustible gas in the furnace and be within the explosion limit due to improper ignition, unstable flame extinction, incomplete purging, etc. Then, when igniting again, it is possible to immediately explode when these combustible gases are ignited;

[0006] (2) The environmental problem of the flame burner is that due to the high calorific value of natural gas, the combustion chamber temperature is as high as 1800°C, and the N2 in the combustion-supporting air undergoes high-temperature oxidation, causing NOx pollution;

[0007] (3) Meanwhile, such burners produce open flames, and the fire prevention distance requirements from Class A process units and hydrocarbon storage tanks are greater than 30 mm. The function of the mobile LNG emergency gasification device is to be used in the LNG gasification station or connected to the LNG storage tank to cope with scenarios such as urban gas peak shaving or temporary supply during the maintenance of industrial and civil gas facilities. It is difficult to meet the fire prevention distance requirements. Summary of the Invention

[0008] The object of the present invention is to solve the problems existing in the above-mentioned prior art, develop an LNG emergency gasification skid-mounted device with an explosion-proof level reaching IIA, and use catalytic combustion to replace the traditional flame combustion method to achieve an overall explosion-proof design for the skid-mounted device; eliminate the explosion risk brought by the flame in the traditional device; the combustion chamber temperature is reduced to below 550 °C, which can effectively inhibit the occurrence of the thermal effect NOx generation reaction; different from the flame combustion method, flameless combustion allows a higher reaction pressure, so the size of the burner and the heat exchange system can be reduced, and the device integration degree can be improved.

[0009] The LNG emergency gasification device provided by the present invention includes an air compressor, an electric heater, an attached reactor, an LNG-air heat exchanger, and a dual-functional heat exchange reactor. The dual-functional heat exchange reactor includes a reactor shell, a catalytic combustion reaction tube located inside the reactor shell, and a spiral LNG gasification coil located inside the reactor shell and surrounding the outer periphery of the catalytic combustion reaction tube. The reactor shell is provided with a flue gas outlet for discharging the flue gas in the inner cavity of the reactor shell.

[0010] Among them, the air pipeline is connected to the inlet of the air compressor. The outlet pipeline of the air compressor is divided into three branches. The first branch is connected to the inlet of the electric heater through the first valve. The second branch is connected to the air inlet of the LNG-air heat exchanger through the second valve. The third branch is connected to the inlet of the catalytic combustion reaction tube of the dual-functional heat exchange reactor through the third valve.

[0011] The liquefied natural gas pipeline is divided into two branches. The first branch is connected to the natural gas inlet of the LNG-air heat exchanger through the fourth valve. The natural gas outlet pipeline of the LNG-air heat exchanger and the outlet pipeline of the electric heater (preferably after convergence) are connected to the inlet of the attached reactor. The outlet pipeline of the attached reactor is connected to the inlet of the catalytic combustion reaction tube of the dual-functional heat exchange reactor.

[0012] The second branch of the liquefied natural gas pipeline is connected to the inlet of the spiral LNG gasification coil of the dual-functional heat exchange reactor through the fifth valve. The outlet pipeline of the spiral LNG gasification coil of the dual-functional heat exchange reactor is divided into two branches. One branch is a natural gas transmission pipeline, and the other branch is connected to the inlet of the catalytic combustion reaction tube of the dual-functional heat exchange reactor through the sixth valve. The catalytic combustion reaction tube is filled with a catalytic combustion catalyst.

[0013] A first thermometer may be provided on the inlet pipeline of the attached reactor (e.g., on the converging pipeline of the natural gas outlet pipeline of the LNG-air heat exchanger and the outlet pipeline of the electric heater).

[0014] A second thermometer may be provided on the outlet pipeline of the attached reactor. The attached reactor may, for example, adopt a straight cylindrical adiabatic reactor, which may also be referred to as an auxiliary activation reactor here.

[0015] A third thermometer may be provided at the inlet of the catalytic combustion reaction tube, and a fourth thermometer may be provided near the outlet of the catalytic combustion reaction tube, preferably at the center position of the outlet of the catalytic combustion reaction tube.

[0016] A fifth thermometer may be provided on the outlet pipeline of the spiral LNG vaporization coil.

[0017] A sixth thermometer may be provided on the LNG outlet pipeline of the LNG-air heat exchanger.

[0018] A seventh thermometer may be provided on the air outlet pipeline of the LNG-air heat exchanger.

[0019] An eighth thermometer may be provided on the flue gas outlet pipeline of the dual-functional heat exchange reactor.

[0020] On the upper and lower pipe walls of the catalytic combustion reaction tube, for example, at the 1 / 3 and 2 / 3 of the reaction tube height on the wall of reaction tube 8, a ninth thermometer and a tenth thermometer may be respectively provided for measuring the wall temperature of the reaction tube. The wall temperature needs to be higher than the catalyst activation temperature, and the temperature of the reaction tube wall (the ninth thermometer and the tenth thermometer) is controlled by controlling the LNG flow rate and the temperature of the fourth thermometer.

[0021] A first pressure gauge may be provided on the outlet pipeline of the air compressor (before it branches into three branches).

[0022] A second pressure gauge may be provided on the flue gas outlet pipeline of the dual-functional heat exchange reactor.

[0023] A third pressure gauge may be provided on the outlet pipeline of the spiral LNG vaporization coil.

[0024] A first flowmeter may be provided on the LNG outlet pipeline of the LNG-air heat exchanger.

[0025] A second flowmeter may be provided on the second branch of the outlet pipeline of the air compressor.

[0026] A third flowmeter may be provided on the third branch of the outlet pipeline of the air compressor.

[0027] A fourth flowmeter may be provided on the first branch of the outlet pipeline of the air compressor.

[0028] A fifth flowmeter may be provided on a branch line of the outlet pipeline of the spiral LNG vaporization coil, which is a natural gas transmission pipeline, and a sixth flowmeter may be provided on another branch line of the outlet pipeline of the spiral LNG vaporization coil.

[0029] The air pipeline may be provided with a seventh valve.

[0030] The liquefied natural gas pipeline may be provided with an eighth valve.

[0031] A ninth valve may be provided on the flue gas outlet pipeline provided on the reactor shell for discharging the flue gas in the inner cavity of the reactor shell.

[0032] A tenth valve may be provided on a branch line branched from the outlet pipeline of the spiral LNG vaporization coil, that is, the natural gas transmission pipeline, and preferably it is behind the fifth flowmeter (F05).

[0033] The dual-functional heat exchange reactor includes a reactor shell, a catalytic combustion reaction tube located inside the shell, a spiral LNG vaporization coil surrounding the catalytic combustion reaction tube, and a flue gas passage (the space between the outer wall of the catalytic combustion reaction tube and the inner wall of the reactor shell and the outside of the spiral LNG vaporization coil) serving as the inner cavity of the reactor shell. The catalyst combustion reaction tube is of a cylindrical structure, with an air inlet provided at the upper part, and the air inlet is not connected to the reactor cylinder body, and is used to receive gas and air. The bottom is of a sieve hole structure and is connected to the inner cavity of the reactor shell, while supporting the catalyst and not hindering the flue gas from entering the flue gas passage. Preferably, the sieve hole size is 1-10 mm, preferably 3-5 mm.

[0034] The spiral LNG vaporization coil is provided with an LNG inlet, and the LNG inlet is located at the lower part of the reactor. For example, the center position of the inlet is 0-10 cm higher than the bottom of the catalytic combustion reaction tube, preferably 3-5 cm, so as to receive the radiation of the outer wall temperature of the reaction tube. The spiral LNG vaporization coil is also provided with an NG outlet after the LNG is vaporized. The NG outlet is located at the upper part of the reactor. Preferably, the center position of the outlet is 0-10 cm lower than the top of the reactor shell, preferably 3-5 cm, so as to make full use of the flue gas heat. The LNG inlet and the NG outlet are not connected to the inner cavity (cylinder body) of the reactor shell.

[0035] Preferably, the inner diameter range of the reactor shell is, for example, 300-1500 mm, the wall thickness is, for example, 1-7 mm, the outer diameter of the spiral of the spiral LNG vaporization coil is, for example, 280-1480 mm, the inner diameter of the coil is, for example, 6-32 mm, and the wall thickness is, for example, 1-7 mm; the inner diameter of the catalytic combustion reaction tube is, for example, 200-1450 mm, and the wall thickness is, for example, 1-7 mm.

[0036] The reactor shell (cylindrical body) is provided with a flue gas outlet, usually located at the top of the reactor shell, for discharging the heat-exchanged flue gas from the reactor. A blowdown port and a manual valve for controlling the opening and closing of the blowdown port are also provided at the lower part or bottom for discharging residues, powders generated during the catalyst loading and disassembly processes, or condensed water generated at the initial stage of system startup from the reactor. Preferably, the flue gas outlet and the blowdown port are arranged at the central positions of the upper and lower surfaces of the cylindrical body and communicate with the reactor shell (cylindrical body).

[0037] The third thermometer is arranged at the inlet of the catalytic combustion reaction tube and on the upper surface of the catalyst bed for measuring the temperature of the upper surface of the catalyst bed; the fourth thermometer is arranged at the central position of the lower bottom surface of the catalytic combustion reaction tube for measuring the temperature of the flue gas at the outlet of the reaction tube.

[0038] Among them, the LNG in the coil absorbs the heat of the high-temperature flue gas on the one hand and the radiant heat of the outer pipe wall of the catalytic combustion reaction tube on the other hand to complete the gasification process.

[0039] The functions of the blowdown port are as follows: ① During the catalyst loading process, some catalyst residues and powders will appear. After the catalyst is loaded, air needs to be used to blow these impurities out of the system through the blowdown port; ② At the initial stage of system startup, the temperature in the flue gas channel is relatively low. At this stage, the water generated by the catalytic combustion reaction will condense in the flue gas channel and needs to be discharged in time to avoid soaking the catalyst. After the flue gas temperature of the dual-functional heat exchange reactor, that is, the eighth thermometer arranged on the flue gas outlet pipe of the dual-functional heat exchange reactor, reaches above 100 °C, no more water will condense in the flue gas channel.

[0040] Among them, the electric heater, preferably an explosion-proof electric heater, an attached reactor, and an LNG-air heat exchanger constitute an auxiliary activation system (auxiliary heating system). Its function is to provide heat for the dual-functional heat exchange reactor in the early stage of startup, so that the upper-layer catalyst in the catalytic combustion reaction tube quickly reaches the activation temperature. Then, the raw material gas starts to be introduced into the catalytic combustion reaction tube gradually. After the entire catalyst bed reaches the activation temperature, the auxiliary activation system can be shut down;

[0041] Among them, the electric heater is used to heat the air entering the attached reactor;

[0042] Among them, the LNG-air heat exchanger uses air to gasify a small amount of LNG (liquefied natural gas) to provide NG (natural gas) for the attached reactor;

[0043] Among them, the hot air from the electric heater and the NG from the LNG-air heat exchanger are mixed and then enter the attached reactor. Under the action of the catalyst, a methane catalytic combustion reaction occurs. The temperature of the flue gas at the outlet of the catalytic combustion reaction tube reaches 350 - 538 °C and enters the catalyst bed of the dual-functional heat exchange reactor through a pipeline, gradually heating the bed to the activation temperature.

[0044] Among them, the temperature control range at the center position of the outlet of the catalytic combustion reaction tube is 350-538 °C, and the specific value is determined according to the LNG composition. The principle is to be lower than the ignition point of any component in the LNG composition. The temperature here must be lower than the ignition points of all components of the LNG. For example, if the LNG is 100% methane, then this point is controlled below 538 °C. If there is propane in the LNG composition, then this point is controlled below 450 °C.

[0045] Among them, the catalysts filled in the attached reactor and the dual-functional heat exchange reactor are catalytic combustion catalysts. For example, Pb-Pt / cordierite, Pb-Pt-Ce-Zr / Al known in the art can be used. 2 O 3 、Pt-CuMnCeOx / cordierite, La-Fe-Zr / molecular sieve, La-Mn-Ni / perovskite, Ag-Mn-Cu / cordierite, MO-MCo 2 O 4 (M = Cu, Ni) composite system, Cu-Mn / Al 2 O 3 and other one or more of noble metal and non-noble metal catalytic combustion catalysts. The activation temperature of the catalyst is 180-360 °C.

[0046] Among them, the principle for controlling the outer wall temperature of the catalytic combustion reaction tube is to be 0-100 °C higher than the activation temperature of the catalyst, such as 1-50 °C, 2-10 °C, 3-8 °C, etc., but not higher than the ignition point of any LNG component.

[0047] Among them, the temperature distribution inside the catalytic combustion reaction tube is as follows: Since the LNG gasification continuously absorbs the radiant heat of the catalytic combustion reaction tube wall and the heat of the flue gas, the flue gas temperature gradually decreases. When the flue gas temperature is lower than the outer wall temperature of the catalytic combustion reaction tube, the flue gas absorbs heat from the outer wall of the catalytic combustion reaction tube and transfers it to the LNG gasification coil. Therefore, in the radial direction, a temperature distribution with a high center and a lower value closer to the wall is formed, and in the axial direction, the temperature distribution is the lowest at the inlet and the highest at the outlet.

[0048] Among them, NOx in the flue gas ≤ 5 ppm;

[0049] Preferably, valves V01-V10 are all pneumatic control valves;

[0050] Preferably, all instruments are purchased as explosion-proof types. The outlet temperature of the catalytic combustion reaction tube is maintained below the ignition point of the medium, and no open fire is generated in the entire system.

[0051] The second aspect of the present invention provides a method for gasifying liquefied natural gas using the above LNG emergency gasification device. The method includes the following steps:

[0052] Feed air (at ambient temperature and pressure) from an air pipeline into a compressor, start the air compressor to compress the air to 5 - 300 KPa. Feed liquefied natural gas (temperature range generally -170 to -140 °C, pressure range generally 0.1 - 0.5 MPa) from a liquefied natural gas pipeline. Control the opening degrees of the first valve and the second valve so that the gas volume flow ratio of the first branch and the second branch separated from the outlet pipeline of the air compressor is 1 - 30:1, further 2 - 20:1, further 5 - 10:1. The flow ratio between the gas passing through the second branch and the liquefied natural gas passing through the first branch pipe separated from the liquefied natural gas pipeline is 8 - 50:1, further 10 - 40:1, further 12 - 35:1 or 14 - 20:1. Heat the liquefied natural gas to -20 to 30 °C, further 5 - 10 °C, and further 6 - 8 °C in an LNG-air heat exchanger;

[0053] Turn on the electric heater and gradually increase the temperature of the gas at the outlet of the electric heater to between 180 and 320 °C;

[0054] The high-temperature air from the outlet of the electric heater and the NG (natural gas) from the outlet of the LNG-air heat exchanger converge. The volume ratio range of the high-temperature air from the outlet of the electric heater to the natural gas from the outlet of the LNG-air heat exchanger is generally 11 - 90:1, preferably 15 - 80:1, or 20 - 70:1, or 30 - 65:1, or 35 - 60:1, or 40 - 60:1. Enter the auxiliary reactor. After heating the mixed gas of high-temperature air and natural gas to 10 - 50 °C higher than the catalyst activation temperature, under a pressure of 5 - 300 KPa, the natural gas reacts with the oxygen in the air under the action of the catalyst, releasing a large amount of reaction heat. The temperature of the gas at the outlet of the attached reactor is adjusted to between 350 and 538 °C;

[0055] The high-temperature flue gas from the attached reactor gradually heats the inlet gas temperature of the catalytic combustion reaction tube in the dual-function heat exchange reactor to 10-50°C higher than the catalyst activation temperature (the catalyst activation temperature is 180-360°C), and then gradually opens the third valve to introduce air (i.e., unheated air) into the dual-function heat exchange reactor, and gradually opens the fifth valve on the second branch pipe of the liquefied natural gas pipeline and the sixth valve on another branch line of the outlet pipe of the spiral LNG gasification coil of the dual-function heat exchange reactor (so that the volume ratio of air to LNG is in the range of 11-90:1, preferably 15-80:1, or 20-70:1, or 30-60:1, or 35-55:1, or 40-50:1). The LNG is gasified in the coil by the flue gas discharged from the catalytic combustion reaction tube in the dual-function heat exchange reactor, and another branch line separated from the outlet pipe of the spiral LNG gasification coil of the dual-function heat exchange reactor is connected to the gas from the air compressor. The air of the third branch separated from the outlet pipeline merges and enters the dual-function heat exchange reactor to start the catalytic combustion reaction. The increase in the flow rate of the third branch of the outlet pipeline of the air compressor (the third flowmeter) and the other branch of the outlet pipeline of the spiral LNG gasification coil (the sixth flowmeter) depends on the inlet gas temperature of the catalytic combustion reaction tube in the dual-function heat exchange reactor. During the process, the inlet point temperature of the catalytic combustion reaction tube is ensured to be greater than the catalyst activation temperature. At the same time, the flow rate ratio of the third branch of the outlet pipeline of the air compressor (the third flowmeter) and the other branch of the outlet pipeline of the spiral LNG gasification coil (the sixth flowmeter) is generally 11 to 90:1, preferably 15 to 80:1, or 20 to 70:1, or 30-65:1, or 35-60:1, or 40 to 60:1, to ensure that the temperature near the outlet of the catalytic combustion reaction tube, preferably the center position of the outlet of the catalytic combustion reaction tube (the fourth thermometer) is lower than the ignition point of any component of LNG;

[0056] When the bed temperature near the outlet of the catalytic combustion reaction tube, preferably at the center of the outlet of the catalytic combustion reaction tube, reaches the activation temperature, the auxiliary activation (heating) system (including the electric heater, the auxiliary reactor, and the LNG-air heat exchanger) is stopped, and the combustion reaction is maintained only by supplying gas through the third branch of the outlet pipeline of the air compressor and the other branch of the outlet pipeline of the spiral LNG gasification coil;

[0057] When the temperature near the outlet of the catalytic combustion reaction tube, preferably at the center of the outlet of the catalytic combustion reaction tube, reaches 350-540°C, a branch line of the outlet pipeline of the spiral LNG gasification coil, i.e., a valve on the natural gas transmission pipeline, is gradually opened to transport natural gas to the outside.

[0058] Adjust the natural gas delivery volume of the natural gas pipeline (e.g., through a flowmeter), and adjust the flow rates of the third branch of the outlet pipeline of the air compressor (third flowmeter) and another branch of the outlet pipeline of the spiral LNG vaporization coil (sixth flowmeter), so as to ensure that the temperature at the natural gas outlet temperature point of the natural gas pipeline is 0 - 20°C, the temperature at the flue gas outlet temperature point provided on the flue gas pipeline is 20 - 40°C, and the upper and lower pipe wall temperatures of the catalytic combustion reaction tube are 0 - 100°C higher than the catalyst activation temperature. While ensuring that the temperature and flow rate of the transported natural gas meet the user's requirements, strictly control the fuel consumption.

[0059] Advantages of the present invention

[0060] The present invention eliminates the explosion hazard caused by the flame in the traditional device; the combustion chamber temperature is reduced to below 550°C, which can effectively inhibit the occurrence of the thermal effect NOx generation reaction; different from the flame combustion mode, flameless combustion allows a higher reaction pressure, thereby reducing the size of the burner and the heat exchange system, and improving the device integration. In addition, the utilization of radiant heat is increased, and no heat exchange medium such as water is required. Description of the drawings

[0061] Figure 1 It is a schematic diagram of the LNG emergency vaporization device of the present invention.

[0062] Figure 2 It is a schematic diagram of the structure of the dual-functional heat exchange reactor. Detailed implementation manners

[0063] The present invention will be further described below with reference to the drawings.

[0064] As Figure 1 and Figure 2 shown, the present invention provides an LNG emergency vaporization device, which includes an air compressor C01, an electric heater E01, an attached reactor R01, an LNG-air heat exchanger E02, and a dual-functional heat exchange reactor R02. The dual-functional heat exchange reactor R02 includes a reactor shell 5, a catalytic combustion reaction tube 8 located inside the reactor shell, and a spiral LNG vaporization coil 11 located inside the reactor shell and surrounding the outer periphery of the catalytic combustion reaction tube. The reactor shell 5 is provided with a flue gas outlet 3 for discharging the flue gas in the inner cavity of the reactor shell.

[0065] Among them, the air pipeline A-1 is connected to the inlet of the air compressor C01. The outlet pipeline of the air compressor C01 is divided into three branches. The first branch A-2 is connected to the inlet of the electric heater E01 through the first valve V02. The second branch A-3 is connected to the air inlet of the LNG-air heat exchanger E02 through the second valve V04. The third branch A-4 is connected to the inlet of the catalytic combustion reaction tube of the dual-functional heat exchange reactor R02 through the third valve V03.

[0066] The liquefied natural gas pipeline LNG-1 is divided into two branch pipes. The first branch pipe LNG-2 is connected to the natural gas inlet of the LNG-air heat exchanger E02 via the fourth valve V06. The natural gas outlet pipeline NG-1 of the LNG-air heat exchanger E02 and the outlet pipeline A-5 of the electric heater E01 (preferably after the two converge) are connected to the inlet of the attached reactor R01. The outlet pipeline A-6 of the attached reactor R01 is connected to the inlet of the catalytic combustion reaction tube of the dual-functional heat exchange reactor R02.

[0067] The second branch pipe LNG-3 of the liquefied natural gas pipeline LNG-1 is connected to the inlet of the spiral LNG vaporization coil 11 of the dual-functional heat exchange reactor R02 via the fifth valve V07. The outlet pipeline of the spiral LNG vaporization coil 11 of the dual-functional heat exchange reactor R02 is divided into two branch lines. One branch line is the natural gas transmission pipeline NG-3, and the other branch line NG-2 is connected to the inlet of the catalytic combustion reaction tube of the dual-functional heat exchange reactor R02 via the sixth valve V09. The catalytic combustion reaction tube is filled with a catalytic combustion catalyst.

[0068] A first thermometer T01 may be provided on the inlet pipeline of the attached reactor R01 (for example, on the converging pipeline of the natural gas outlet pipeline NG-1 of the LNG-air heat exchanger E02 and the outlet pipeline A-5 of the electric heater E01).

[0069] A second thermometer T02 may be provided on the outlet pipeline of the attached reactor R01.

[0070] A third thermometer T03 may be provided at the inlet of the catalytic combustion reaction tube 8, and a fourth thermometer T04 may be provided near the outlet of the catalytic combustion reaction tube, preferably at the center position of the outlet of the catalytic combustion reaction tube.

[0071] A fifth thermometer T05 may be provided on the outlet pipeline of the spiral LNG vaporization coil 11.

[0072] A sixth thermometer T06 may be provided on the LNG outlet pipeline of the LNG-air heat exchanger E02.

[0073] A seventh thermometer T07 may be provided on the air outlet pipeline of the LNG-air heat exchanger E02.

[0074] An eighth thermometer T08 may be provided on the flue gas outlet pipeline of the dual-functional heat exchange reactor R02.

[0075] On the upper and lower pipe walls of the catalytic combustion reaction tube, for example, at the 1 / 3 and 2 / 3 heights of the reaction tube 8 on the wall of the reaction tube, a ninth thermometer T09 and a tenth thermometer T10 can be respectively provided to measure the wall temperature of the reaction tube 8. The wall temperature needs to be higher than the catalyst activation temperature, and the temperatures of T09 and T10 are controlled by controlling the LNG flow rate and the temperature of the fourth thermometer T04.

[0076] A first pressure gauge P01 can be provided on the outlet pipe of the air compressor C01 (before it branches into three branches).

[0077] A second pressure gauge P02 can be provided on the flue gas outlet pipe of the dual-functional heat exchange reactor R02.

[0078] A third pressure gauge P03 can be provided on the outlet pipe of the spiral LNG vaporization coil 11.

[0079] A first flowmeter F01 can be provided on the LNG outlet pipe of the LNG-air heat exchanger E02.

[0080] A second flowmeter F02 can be provided on the second branch A-3 of the outlet pipe of the air compressor C01.

[0081] A third flowmeter F03 can be provided on the third branch A-4 of the outlet pipe of the air compressor C01.

[0082] A fourth flowmeter F04 can be provided on the first branch A-2 of the outlet pipe of the air compressor C01.

[0083] A fifth flowmeter F05 can be provided on a branch line, i.e., the natural gas transmission pipeline NG-3, of the outlet pipe of the spiral LNG vaporization coil 11, and a sixth flowmeter F06 can be provided on another branch line NG-2 of the outlet pipe of the spiral LNG vaporization coil 11.

[0084] A seventh valve V01 can be provided on the air pipe A-1.

[0085] An eighth valve V05 can be provided on the liquefied natural gas pipeline LNG-1.

[0086] A ninth valve V08 can be provided on the flue gas outlet pipe A-7 provided on the reactor housing 5 for discharging the flue gas in the inner cavity of the reactor housing.

[0087] A tenth valve V10 can be provided on a branch line, i.e., the natural gas transmission pipeline NG-3, branched from the outlet pipe of the spiral LNG vaporization coil 11, and preferably it is after the fifth flowmeter F05.

[0088] The dual-functional heat exchange reactor includes a reactor shell 5, a catalytic combustion reaction tube 8 located inside the shell, a spiral LNG vaporization coil 11 surrounding the catalytic combustion reaction tube, and a flue gas channel 10 (the space between the outer wall of the catalytic combustion reaction tube 8 and the inner wall of the reactor shell and the outside of the spiral LNG vaporization coil) that serves as the inner cavity of the reactor shell. The catalyst combustion reaction tube 8 is of a cylindrical structure, with an air inlet 2 provided at the upper part. The air inlet 2 is not connected to the reactor cylinder body and is used to receive gas and air. The bottom is of a sieve hole structure, which is connected to the inner cavity of the reactor shell. While supporting the catalyst, it does not prevent the flue gas from entering the flue gas channel 10. Preferably, the sieve hole size is 1-10 mm, preferably 3-5 mm.

[0089] The spiral LNG vaporization coil 11 is provided with an LNG inlet 1. The LNG inlet 1 is located at the lower part of the reactor. For example, the central position of the inlet 1 is 0-10 cm higher than the bottom of the catalytic combustion reaction tube 8, preferably 3-5 cm, which is convenient for receiving the radiation of the outer wall temperature of the reaction tube. The spiral LNG vaporization coil is also provided with an NG outlet 4 after the LNG is vaporized. The NG outlet 4 is located at the upper part of the reactor. Preferably, the central position of the outlet 4 is 0-10 cm lower than the top of the reactor shell, preferably 3-5 cm, which is convenient for making full use of the heat of the flue gas. Both the LNG inlet 1 and the NG outlet 4 are not connected to the inner cavity (cylinder body) of the reactor shell.

[0090] The inner diameter range of the reactor shell 5 is 300-1500 mm, and the wall thickness is 1-7 mm. The spiral outer diameter of the spiral LNG vaporization coil 11 is 280-1480 mm, and the inner diameter of the coil is 6-32 mm; the inner diameter of the catalytic combustion reaction tube 8 is 200-1450 mm, and the wall thickness is 1-7 mm.

[0091] The reactor shell (cylinder body) 5 is provided with a flue gas outlet 3, which is usually located at the top of the reactor shell 5 and is used to discharge the heat-exchanged flue gas from the reactor. A sewage outlet 7 and a manual valve 12 for controlling the opening and closing of the sewage outlet are also provided at the lower part or the bottom, which are used to discharge the residues, powders generated during the catalyst loading and unloading process or the condensed water generated at the initial stage of the system startup from the reactor. Preferably, the flue gas outlet 3 and the sewage outlet 7 are arranged at the central positions of the upper and lower surfaces of the cylinder body and are connected to the cylinder body.

[0092] The third thermometer T03 is arranged at the inlet of the catalytic combustion reaction tube 8 and the upper surface of the catalyst bed, and is used to measure the temperature of the upper surface of the catalyst bed; the fourth thermometer T04 is arranged at the central position of the lower bottom surface of the catalytic combustion reaction tube 8 and is used to measure the temperature of the flue gas at the outlet of the reaction tube.

[0093] Among them, on the one hand, the LNG in the coil absorbs the heat of the high-temperature flue gas, and at the same time absorbs the radiation heat of the outer tube wall of the catalytic combustion reaction tube to complete the gasification process.

[0094] The functions of the sewage outlet 12 are as follows: ① During the process of loading the catalyst, there will be some catalyst residues and powders. After loading the catalyst, air is needed to blow these impurities out of the system through 12; ② At the initial stage of system startup, the temperature in the flue gas passage 10 is relatively low. At this stage, the water generated by the catalytic combustion reaction will condense in the flue gas passage 10 and needs to be discharged in time to avoid soaking the catalyst. After the flue gas temperature of the dual-functional heat exchange reactor R02, that is, the eighth thermometer T08 installed on the flue gas outlet pipe of the dual-functional heat exchange reactor R02, reaches above 100 °C, no more water will condense in the flue gas passage 10.

[0095] Among them, the electric heater, preferably the explosion-proof electric heater E01, the attached reactor R01, and the LNG-air heat exchanger E02 constitute the auxiliary activation system. Its function is to provide heat for the dual-functional heat exchange reactor in the early stage of startup, so that the upper-layer catalyst in the catalytic combustion reaction tube quickly reaches the activation temperature. After that, the raw material gas starts to be introduced into the catalytic combustion reaction tube gradually. After the overall catalyst bed reaches the activation temperature, the auxiliary activation system can be shut down.

[0096] Among them, E01 is used to heat the air entering R01.

[0097] Among them, the LNG-air heat exchanger E02 uses air to gasify a small amount of LNG (liquefied natural gas) to provide NG (natural gas) for the attached reactor.

[0098] Among them, the hot air from E01 and the NG from E02 are mixed and then enter the attached reactor R01. The methane catalytic combustion reaction occurs under the action of the catalyst. The flue gas temperature T04 at the outlet of the catalytic combustion reaction tube reaches 350 - 538 °C and enters the catalyst bed of the dual-functional heat exchange reactor R02 through the pipeline, gradually heating the bed to the activation temperature.

[0099] Among them, the temperature control range of the T04 point at the center position of the outlet of the catalytic combustion reaction tube is 350 - 538 °C. The specific value is determined according to the composition of LNG. The principle is to be lower than the ignition point of any component in the LNG composition. The temperature here must be lower than the ignition points of all components of LNG. For example, if the LNG is 100% methane, then this point is controlled below 538 °C. If there is propane in the LNG composition, then this point is controlled below 450 °C.

[0100] Among them, the catalysts loaded in R01 and R02 are catalytic combustion catalysts. For example, Pb-Pt / cordierite, Pb-Pt-Ce-Zr / Al 2 O 3 known in the art such as, Pt-CuMnCeOx / cordierite, La-Fe-Zr / molecular sieve, La-Mn-Ni / perovskite, Ag-Mn-Cu / cordierite, MO-MCo 2 O 4(M = Cu, Ni) composite system, Cu-Mn / Al 2 O 3 One or more of noble metals and non-noble metal catalytic combustion catalysts such as etc. The activation temperature of the catalyst is 180 - 360 °C.

[0101] Among them, the principle for controlling the outer wall temperature of the catalytic combustion reaction tube is to be 0 - 100 °C higher than the activation temperature of the catalyst, such as 1 - 50 °C, 2 - 10 °C, or 3 - 8 °C, etc., but not higher than the ignition point of any component of LNG.

[0102] Among them, the temperature distribution inside the catalytic combustion reaction tube is as follows: Since the gasification of LNG continuously absorbs the radiant heat of the catalytic combustion reaction tube wall and the heat of the flue gas, the temperature of the flue gas gradually decreases. When the temperature of the flue gas is lower than the outer wall temperature of the catalytic combustion reaction tube, the flue gas absorbs heat from the outer wall of the catalytic combustion reaction tube and transfers it to the LNG vaporization coil. Therefore, in the radial direction, a temperature distribution with a high center and a lower value closer to the wall is formed, and in the axial direction, the temperature distribution is the lowest at the inlet and the highest at the outlet.

[0103] Among them, NOx in the flue gas ≤ 5 ppm.

[0104] Preferably, valves V01 - V10 are all pneumatic control valves.

[0105] Preferably, all instruments are purchased as explosion-proof types. The outlet temperature of the catalytic combustion reaction tube is maintained at a temperature lower than the ignition point of the medium, and no open flame is generated in the whole system.

[0106] The gasification process flow using the above device is as follows:

[0107] Feed air (ambient temperature and pressure) from the air pipeline to air compressor C01. Start air compressor C01 to compress the air to 5 - 300 KPa. Feed liquefied natural gas (temperature range is generally -170 - -140 °C, pressure range is generally 0.1 - 0.5 MPa) from liquefied natural gas pipeline LNG - 1. Control the opening degrees of the first valve V02 (for example, the flow rate is 0.1 - 30 Nm 3 / h) and the second valve V04 (for example, the flow rate is 0.1 - 10 Nm 3 / h) so that the volume flow ratio of the gas in the first branch A - 2 and the second branch A - 3 separated from the outlet pipeline of the air compressor is 1 - 30:1, further 2 - 20:1, further 5 - 10:1. The gas passing through the second branch A - 3 and the liquefied natural gas in the first branch pipe LNG - 2 separated from the liquefied natural gas pipeline LNG - 1 (for example, the flow rate can be 0.01 - 1 Nm 3The flow rate ratio between ( / h) is 8 to 50:1, further 10 - 40:1, further 12 - 35:1 or 14 to 20:1. The liquefied natural gas is heated to -20 to 30 °C in the LNG-air heat exchanger E02, further 5 - 10 °C, and still further 6 - 8 °C;

[0108] Turn on the electric heater E01 and gradually increase the temperature of the gas at the outlet of the electric heater to between 180 and 320 °C;

[0109] The high-temperature air from the outlet of the electric heater E01 and the NG (natural gas) from the outlet of the LNG-air heat exchanger E02 converge. The volume ratio range of the high-temperature air from the outlet of the electric heater E01 to the natural gas from the outlet of the LNG-air heat exchanger E02 is generally 11 to 90:1, further 15 to 80:1, or 20 to 70:1, or 30 - 65:1, or 35 - 60:1, or 40 to 60:1. They enter the auxiliary reactor R01. After the temperature of the mixed gas of high-temperature air and natural gas (point T01) is heated to 10 - 50 °C higher than the catalyst activation temperature, under a pressure of 5 to 300 KPa, the natural gas reacts with the oxygen in the air under the action of the catalyst, releasing a large amount of reaction heat. The temperature of the gas at the outlet of the attached reactor R01 is adjusted to between 350 and 538 °C;

[0110] The high-temperature flue gas from the attached reactor R01 gradually heats the gas temperature at the inlet (point T03) of the catalytic combustion reaction tube 8 in the dual-functional heat exchange reactor R02 to 10 - 50 °C higher than the catalyst activation temperature (the catalyst activation temperature is 180 - 360 °C), and then gradually opens the third valve V03 to introduce air (i.e., unheated air) into the dual-functional heat exchange reactor R02. Gradually open the fifth valve V07 on the second branch LNG-3 of the liquefied natural gas pipeline LNG-1 and the sixth valve V09 on another branch NG-2 of the outlet pipeline of the spiral LNG vaporization coil 11 in the dual-functional heat exchange reactor R02 (so that the volume ratio of air to LNG ranges from 11 to 90:1, further 15 to 80:1, or 20 to 70:1, or 30 - 65:1, or 35 - 60:1, or 40 to 60:1). The LNG is vaporized by the flue gas discharged from the catalytic combustion reaction tube in the dual-functional heat exchange reactor R02. After the air from another branch NG-2 separated from the outlet pipe of the spiral LNG vaporization coil 11 in the dual-functional heat exchange reactor R02 converges with the air from the third branch A-4 separated from the outlet pipeline of the air compressor C01, it enters the dual-functional heat exchange reactor R02 to start the catalytic combustion reaction. The increase in the flow rates of the third branch A-4 (the third flowmeter F03) of the outlet pipeline of the air compressor C01 and another branch NG-2 (the sixth flowmeter F06) of the outlet pipeline of the spiral LNG vaporization coil 11 depends on the gas temperature at the inlet (point T03) of the catalytic combustion reaction tube 8 in the dual-functional heat exchange reactor R02. During the process, ensure that the temperature at the inlet point of the catalytic combustion reaction tube 8 is higher than the catalyst activation temperature. At the same time, the flow rate ratio (the ratio of F03 to F06) of the third branch A-4 (the third flowmeter F03) of the outlet pipeline of the air compressor C01 to another branch NG-2 (the sixth flowmeter F06) of the outlet pipeline of the spiral LNG vaporization coil 11 is generally 11 to 90:1, further 15 to 80:1, or 20 to 70:1, or 30 - 65:1, or 35 - 60:1, or 40 to 60:1, to ensure that the temperature near the outlet of the catalytic combustion reaction tube, preferably at the center position of the outlet of the catalytic combustion reaction tube (point T04), is lower than the ignition point of any component of the LNG;

[0111] When the bed temperature near the outlet of the catalytic combustion reaction tube, preferably at the center position of the outlet of the catalytic combustion reaction tube (point T04), reaches the activation temperature, stop the auxiliary activation system (including the electric heater E01, the attached reactor R01, and the LNG-air heat exchanger E02), and only supply gas through the third branch A-4 of the outlet pipeline of the air compressor C01 and another branch NG-2 of the outlet pipeline of the spiral LNG vaporization coil 11 to maintain the combustion reaction;

[0112] When the temperature at the center position (point T04) near the outlet of the catalytic combustion reaction tube, preferably at the outlet of the catalytic combustion reaction tube, reaches 350 - 540 °C, gradually open a branch line separated from the outlet pipeline of the spiral LNG vaporization coil 11, that is, the valve V10 on the natural gas pipeline NG-3, to transport natural gas to the outside.

[0113] Adjust the amount of natural gas transported through the natural gas pipeline NG-3 (for example, through the flowmeter F07), and adjust the flow rates of the third branch A-4 (the third flowmeter F03) of the outlet pipeline of the air compressor C01 and the other branch line NG-2 (the sixth flowmeter F06) of the outlet pipeline of the spiral LNG vaporization coil 11, so as to ensure that the temperature at point T05 at the natural gas outlet of the natural gas pipeline NG-3 is 0 - 20 °C, the temperature at point T08 at the flue gas outlet on the flue gas pipeline A-7 is 20 - 40 °C, and the temperatures at the upper and lower pipe walls T09 and T10 of the catalytic combustion reaction tube are 0 - 100 °C higher than the activation temperature of the catalyst. While ensuring that the temperature and flow rate of the transported natural gas meet the user's requirements, strictly control the fuel consumption.

[0114] According to the volume ratio of F03 and F06 (the volume ratio of air to natural gas is 11 - 90:1), the temperature at the flue gas temperature measurement point T02 (on the reactor outlet pipeline) at the outlet of the attached reactor can be adjusted to be between 350 - 538 °C.

[0115] Example 1

[0116] The composition of LNG is: CH4 - 98.6%, C2H6 - 0.3%, C3H6 - 0.07%, N2 - 1.03%.

[0117] Catalyst: La-Mn-Ni / perovskite.

[0118] ① Open the seventh valve V01, the first valve V02, and the second valve V04, start the air compressor C01, adjust the opening of the second valve V04 so that the reading of the second flowmeter F02 is 1.4 Nm 3 / h, adjust the opening of the first valve V02 so that the reading of the fourth flowmeter F04 is 6.5 Nm 3 / h;

[0119] ② Open the explosion-proof electric heater E01, and gradually raise the temperature at point T01 (on the converging pipeline of the natural gas pipeline NG-1 at the natural gas outlet of the LNG-air heat exchanger E02 and the outlet pipeline A-5 of the electric heater E01) to 280 °C. Open the eighth valve V05, adjust the opening of the fourth valve V06 until the reading of the first flowmeter F01 is 0.1 Nm 3 / h, adjust the second valve V04 so that the temperature at point T6 (on the LNG outlet pipeline of the LNG-air heat exchanger E02) is maintained at 5 - 15 °C.

[0120] ③ After the high-temperature air from E01 and the NG (natural gas) from E02 converge, they enter the auxiliary reactor. Under the action of the catalyst, the natural gas reacts with the oxygen in the air, releasing a large amount of reaction heat, and the temperature at point T02 (on the outlet pipe of reactor R01) rises to 420 °C.

[0121] ④ After the high-temperature flue gas from R01 gradually heats the temperature at point T03 (the inlet of the catalytic combustion reaction tube 8) in the dual-functional heat exchange reactor R02 to 320 °C, the third valve V03 is gradually opened, and air is introduced into R02. The reading of the third flowmeter F03 gradually increases from zero to 6000 Nm 3 / h. The fifth valve V07 and the sixth valve V09 are gradually opened. The LNG is vaporized by the flue gas discharged from the catalytic combustion reaction tube in the coil, and after converging with the air in pipeline A-4 through pipeline NG-2, it enters R02. The reading of the sixth flowmeter F06 gradually increases from zero to 100 Nm 3 / h, and the catalytic combustion reaction starts. The increasing amplitudes of F03 and F06 are determined by the temperature at point T03. During the rectification process, ensure that the temperature at point T03 ≥ 280 °C (the activation temperature of the catalyst), and at the same time, the ratio of F03 to F06 is greater than or equal to 50 to ensure that the temperature at point T04 (the center position of the outlet of the catalytic combustion reaction tube) is lower than 450 °C (the ignition point of propane).

[0122] ⑤ When the bed temperature at point T04 reaches 280 °C, stop the auxiliary heating system, and the catalytic combustion reaction tube can maintain the combustion reaction by supplying gas through pipelines A-4 and NG-2.

[0123] ⑥ When the temperature at point T04 reaches 420 °C, gradually open the tenth valve V10 to transport natural gas to the outside.

[0124] ⑦ Adjust the transported natural gas volume F07, adjust the flow rates of F03 and F06, and at the same time control the temperature at point T05 (the outlet pipe of the spiral LNG vaporization coil 11) to be 5 °C and the temperature at point T08 (the flue gas outlet pipe of the dual-functional heat exchange reactor R02) to be 20 - 30 °C. While ensuring that the temperature and flow rate of the transported natural gas meet the user's requirements, strictly control the fuel consumption.

[0125] ⑧ Finally, the reading of F03 is 6000 Nm 3 / h, the reading of F06 is 100 Nm 3 / h, the external gas transmission volume is 5600 Nm 3 / h, the outlet temperature of the catalytic combustion reaction tube is maintained at a temperature lower than the ignition point of the medium, and no open flame is generated, and no NOx is detected in the flue gas.

[0126] Example 2

[0127] The LNG composition is: CH4 - 98.6%, N2 - 1.4%.

[0128] Catalyst: Pd-Pt / honeycomb ceramic catalytic combustion catalyst.

[0129] ① Open the seventh valve V01, the first valve V02, and the second valve V04, start the air compressor C01, and adjust the opening of the second valve V04 so that the reading of the second flowmeter F02 is 1.4 Nm 3 / h, and adjust the opening of the first valve V02 so that the reading of the fourth flowmeter F04 is 6.5 Nm 3 / h;

[0130] ② Open the explosion-proof electric heater E01, and gradually increase the temperature at point T01 (on the converging pipeline of the natural gas outlet pipeline NG-1 of the LNG-air heat exchanger E02 and the outlet pipeline A-5 of the electric heater E01) to 240 °C. Open the eighth valve V05, adjust the opening of the fourth valve V06 until the reading of the first flowmeter F01 is 0.13 Nm 3 / h, and adjust the second valve V04 to maintain the temperature at point T6 (on the LNG outlet pipeline of the LNG-air heat exchanger E02) at 5 - 15 °C.

[0131] ③ After the high-temperature air from the electric heater E01 and the NG (natural gas) from the LNG-air heat exchanger E02 converge, they enter the auxiliary reactor. Under the action of the catalyst, the natural gas reacts with the oxygen in the air, releasing a large amount of reaction heat, and the temperature of the outlet pipeline of the attached reactor R01 at point T02 rises to 530 °C;

[0132] ④ After the high-temperature flue gas from R01 gradually heats the temperature at point T03 in the dual-functional heat exchange reactor R02 to 270 °C, gradually open V03, introduce air into R02, and the reading of the flowmeter F03 gradually increases from zero to 9000 Nm 3 / h. Gradually open V07 and V09. The LNG is vaporized by the flue gas discharged from the catalytic combustion reaction tube 8 in R02 in the coil, and after converging with the air in the pipeline A-4 through the pipeline NG-2, it enters R02. The reading of the flowmeter F06 gradually increases from zero to 200 Nm 3 / h, and the catalytic combustion reaction starts. The increasing amplitudes of F03 and F06 depend on the temperature at point T03. During the rectification process, ensure that the temperature at point T03 ≥ 240 °C (the activation temperature of the catalyst), and at the same time, the ratio of F03 to F06 is greater than or equal to 50 to ensure that the temperature at point T04 is lower than 538 °C (the ignition point of methane);

[0133] ⑤ When the bed temperature at point T04 reaches 240 °C, stop the auxiliary heating system, and the catalytic combustion reaction tube can maintain the combustion reaction by supplying gas through the pipelines A-4 and NG-2;

[0134] ⑥ When the temperature at point T04 reaches 530 °C, gradually open V10 to transport natural gas to the outside;

[0135] ⑦ Adjust the natural gas delivery volume F07, adjust the flow rates of F03 and F06, and at the same time control the temperature at point T05 to be 5°C and the temperature at point T08 to be 20 - 30°C. While ensuring that the temperature and flow rate of the transported natural gas meet the user's requirements, strictly control the fuel consumption;

[0136] ⑧ Finally, the indication of F03 is 9000 Nm 3 / h, the indication of F06 is 200 Nm 3 / h, the external gas transmission volume is 11000 Nm 3 / h, the temperature at the outlet of the catalytic combustion reaction tube is maintained at a temperature lower than the ignition point of the medium, and no open flame is generated. The NOx in the flue gas is 2.3 ppm.

[0137] The above details the preferred implementation of the present invention. However, it should be understood that the above description is for illustrative purposes only and does not constitute any limitation to the scope of the present invention. Those of ordinary skill in the art can make substitutions or changes to certain features of the present invention without departing from the gist and scope of the present invention, and these substitutions or changes should be regarded as falling within the protection scope of the claims of the present invention.

Claims

1. An LNG emergency vaporization device, which includes an air compressor (C01), an electric heater (E01), an attached reactor (R01), an LNG-air heat exchanger (E02), and a dual-functional heat exchange reactor (R02). The dual-functional heat exchange reactor (R02) includes a reactor shell (5), catalytic combustion reaction tubes (8) filled with catalytic combustion catalysts located inside the reactor shell, and a spiral LNG vaporization coil (11) located inside the reactor shell and surrounding the outer periphery of the catalytic combustion reaction tubes. The reactor shell (5) is provided with a flue gas outlet (3) for discharging the flue gas in the inner cavity of the reactor shell. Wherein, An air pipeline (A-1) is connected to the inlet of the air compressor (C01). The outlet pipeline of the air compressor (C01) is divided into three branches. The first branch (A-2) is connected to the inlet of the electric heater (E01) via a first valve (V02). The second branch (A-3) is connected to the air inlet of the LNG-air heat exchanger (E02) via a second valve (V04). The third branch (A-4) is connected to the inlet of the catalytic combustion reaction tubes of the dual-functional heat exchange reactor (R02) via a third valve (V03). The liquefied natural gas pipeline (LNG-1) is divided into two branches. The first branch (LNG-2) is connected to the natural gas inlet of the LNG-air heat exchanger (E02) via a fourth valve (V06). The natural gas outlet pipeline (NG-1) of the LNG-air heat exchanger (E02) and the outlet pipeline (A-5) of the electric heater (E01) are connected to the inlet of the attached reactor (R01). The outlet pipeline (A-6) of the attached reactor (R01) is connected to the inlet of the catalytic combustion reaction tubes of the dual-functional heat exchange reactor (R02). The second branch (LNG-3) of the liquefied natural gas pipeline (LNG-1) is connected to the inlet of the spiral LNG vaporization coil (11) of the dual-functional heat exchange reactor (R02) via a fifth valve (V07). The outlet pipeline of the spiral LNG vaporization coil (11) of the dual-functional heat exchange reactor (R02) is divided into two branches. One branch is a natural gas transmission pipeline (NG-3), and the other branch (NG-2) is connected to the inlet of the catalytic combustion reaction tubes of the dual-functional heat exchange reactor (R02) via a sixth valve (V09). The natural gas outlet pipeline (NG-1) of the LNG-air heat exchanger (E02) and the outlet pipeline (A-5) of the electric heater (E01) are connected to the inlet of the attached reactor (R01) after they converge. The dual-functional heat exchange reactor also includes a flue gas channel (10) serving as the inner cavity of the reactor shell. The catalytic combustion reaction tubes (8) are of a cylindrical structure, with an air inlet (2) provided at the upper part. The air inlet (2) is not connected to the inner cavity of the reactor shell and is used to receive fuel gas and air. The bottom of the catalytic combustion reaction tubes (8) is of a sieve hole structure and is connected to the inner cavity of the reactor shell, supporting the catalyst while not hindering the flue gas from entering the flue gas channel (10). The spiral LNG vaporization coil (11) is provided with an LNG inlet (1), and the LNG inlet (1) is located at the lower part of the reactor; the spiral LNG vaporization coil (11) is also provided with an NG outlet (4) after LNG vaporization, and the NG outlet (4) is located at the upper part of the reactor. Neither the LNG inlet (1) nor the NG outlet (4) is communicated with the inner cavity of the reactor housing; The flue gas outlet (3) is located at the top of the reactor housing (5) and is used to discharge the heat-exchanged flue gas from the dual-functional heat-exchanging reactor. A drain port (7) and a manual valve (12) for controlling the opening and closing of the drain port are also provided at the lower part or the bottom of the reactor housing (5). The drain port (7) is used to discharge the residues, powders generated during the catalyst loading and unloading processes, or the condensed water generated at the initial stage of system startup from the dual-functional heat-exchanging reactor.

2. The LNG emergency vaporization device according to claim 1, characterized in that, a first thermometer (T01) is provided on the inlet pipe of the attached reactor (R01); and / or a second thermometer (T02) is provided on the outlet pipe of the attached reactor (R01); and / or a third thermometer (T03) is provided at the inlet of the catalytic combustion reaction tube (8), and a fourth thermometer (T04) is provided near the outlet of the catalytic combustion reaction tube; and / or a fifth thermometer (T05) is provided on the outlet pipe of the spiral LNG vaporization coil (11); and / or a sixth thermometer (T06) is provided on the LNG outlet pipe of the LNG-air heat exchanger (E02); and / or a seventh thermometer (T07) is provided on the air outlet pipe of the LNG-air heat exchanger (E02); and / or an eighth thermometer (T08) is provided on the flue gas outlet pipe of the dual-functional heat-exchanging reactor (R02); and / or a ninth thermometer (T09) and a tenth thermometer (T10) are respectively provided on the upper pipe wall and the lower pipe wall of the catalytic combustion reaction tube; and / or a first pressure gauge (P01) is provided on the outlet pipe of the air compressor (C01); and / or a second pressure gauge (P02) is provided on the flue gas outlet pipe of the dual-functional heat-exchanging reactor (R02); and / or a third pressure gauge (P03) is provided on the outlet pipe of the spiral LNG vaporization coil (11); and / or a first flowmeter (F01) is provided on the LNG outlet pipe of the LNG-air heat exchanger (E02); and / or a second flowmeter (F02) is provided on the second branch (A-3) of the outlet pipe of the air compressor (C01); and / or a third flowmeter (F03) is provided on the third branch (A-4) of the outlet pipe of the air compressor (C01); and / or a fourth flowmeter (F04) is provided on the first branch (A-2) of the outlet pipe of the air compressor (C01); and / or a fifth flowmeter (F05) is provided on a branch natural gas transmission pipeline (NG-3) of the outlet pipe of the spiral LNG vaporization coil (11), and a sixth flowmeter (F06) is provided on the other branch (NG-2) of the outlet pipe of the spiral LNG vaporization coil (11); and / or a seventh valve (V01) is provided on the air pipe (A-1); and / or The liquefied natural gas pipeline (LNG-1) is provided with an eighth valve (V05); and / or A ninth valve (V08) is provided on the flue gas outlet pipe (A-7) provided in the reactor shell (5) for discharging the flue gas in the inner cavity of the reactor shell; and / or A tenth valve (V10) is provided on a branch line branched from the outlet pipe of the spiral LNG vaporization coil (11), that is, the natural gas transmission pipeline (NG-3).

3. The LNG emergency vaporization device according to claim 1 or 2, characterized in that The sieve hole size of the sieve hole structure at the bottom of the catalytic combustion reaction tube (8) is 1-10 mm.

4. The LNG emergency vaporization device according to claim 3, characterized in that The sieve hole size of the sieve hole structure at the bottom of the catalytic combustion reaction tube (8) is 3-5 mm.

5. The LNG emergency vaporization device according to claim 1, characterized in that The central position of the LNG inlet (1) of the spiral LNG vaporization coil (11) is 0-10 cm higher than the bottom of the catalytic combustion reaction tube (8).

6. The LNG emergency vaporization device according to claim 5, characterized in that The central position of the LNG inlet (1) of the spiral LNG vaporization coil (11) is 3-5 cm higher than the bottom of the catalytic combustion reaction tube (8).

7. The LNG emergency vaporization device according to claim 5, characterized in that The central position of the NG outlet (4) of the spiral LNG vaporization coil (11) is 0-10 cm lower than the top of the reactor shell.

8. The LNG emergency vaporization device according to claim 7, characterized in that The central position of the NG outlet (4) of the spiral LNG vaporization coil (11) is 3-5 cm lower than the top of the reactor shell.

9. The LNG emergency vaporization device according to claim 1 or 5, characterized in that The flue gas outlet (3) and the sewage outlet (7) are arranged at the central positions of the upper and lower surfaces of the cylinder body of the reactor shell (5) and are communicated with the inner cavity of the reactor shell.

10. A method for vaporizing liquefied natural gas using the LNG emergency vaporization device according to any one of claims 1-9, the method comprising the following steps: Feed air from the air pipeline to the air compressor (C01), start the air compressor (C01) to compress the air to 5~300 KPa, feed liquefied natural gas from the liquefied natural gas pipeline, control the opening degrees of the first valve (V02) and the second valve (V04), so that the gas volume flow ratio of the first branch (A-2) and the second branch (A-3) branched from the outlet pipe of the air compressor is 1~30:1, and the flow ratio between the gas passing through the second branch (A-3) and the liquefied natural gas passing through the first branch pipe (LNG-2) branched from the liquefied natural gas pipeline (LNG-1) is 8~50:1, and heat the liquefied natural gas to -20~30 °C in the LNG-air heat exchanger (E02); Open the electric heater (E01) and gradually increase the temperature of the gas at the outlet of the electric heater to between 180~320 °C; The high-temperature air from the electric heater (E01) and the natural gas from the LNG-air heat exchanger (E02) converge. The volumetric flow ratio of the high-temperature air from the electric heater (E01) to the natural gas from the LNG-air heat exchanger (E02) ranges from 11 to 90:1 and enters the attached reactor (R01). After the mixed gas of high-temperature air and natural gas is heated to 10 - 50 °C higher than the catalyst activation temperature, under a pressure of 5 - 300 KPa, the natural gas reacts with the oxygen in the air under the action of the catalyst, releasing a large amount of reaction heat. The temperature of the gas at the outlet of the attached reactor (R01) is adjusted to between 350 and 538 °C; The high-temperature flue gas from the attached reactor (R01) gradually heats the inlet gas temperature of the catalytic combustion reaction tubes (8) in the dual-functional heat exchange reactor (R02) to 10 - 50 °C higher than the catalyst activation temperature. Then, gradually open the third valve (V03) to supply air to the dual-functional heat exchange reactor (R02). Gradually open the fifth valve (V07) on the second branch (LNG-3) of the liquefied natural gas pipeline (LNG-1) and the sixth valve (V09) on another branch line (NG-2) of the outlet pipeline of the spiral LNG vaporization coil (11) of the dual-functional heat exchange reactor (R02), so that the volumetric ratio of air to LNG ranges from 11 to 90:

1. The LNG is vaporized by the flue gas discharged from the catalytic combustion reaction tubes in the dual-functional heat exchange reactor (R02) in the coil. After the air from another branch line (NG-2) separated from the outlet pipe of the spiral LNG vaporization coil (11) of the dual-functional heat exchange reactor (R02) converges with the air from the third branch (A-4) separated from the outlet pipeline of the air compressor (C01), it enters the dual-functional heat exchange reactor (R02) to start the catalytic combustion reaction. The increase in the flow rates of the third branch (A-4) of the outlet pipeline of the air compressor (C01) and another branch line (NG-2) of the outlet pipeline of the spiral LNG vaporization coil (11) depends on the inlet gas temperature of the catalytic combustion reaction tubes (8) in the dual-functional heat exchange reactor (R02). During the process, ensure that the inlet point temperature of the catalytic combustion reaction tubes (8) is higher than the catalyst activation temperature. At the same time, the flow rate ratio of the third branch (A-4) of the outlet pipeline of the air compressor (C01) to another branch line (NG-2) of the outlet pipeline of the spiral LNG vaporization coil (11) is 11 - 90:1, and ensure that the temperature near the outlet of the catalytic combustion reaction tubes is lower than the ignition point of any component of the LNG; When the bed temperature near the outlet of the catalytic combustion reaction tubes reaches the activation temperature, stop the auxiliary activation system and maintain the combustion reaction only by supplying gas from the third branch (A-4) of the outlet pipeline of the air compressor (C01) and another branch line (NG-2) of the outlet pipeline of the spiral LNG vaporization coil (11); After the temperature near the outlet of the catalytic combustion reaction tube reaches 350 - 540 °C, gradually open the tenth valve (V10) on a branch line separated from the outlet pipeline of the spiral LNG vaporization coil (11), i.e., the natural gas pipeline (NG-3), to transport natural gas to the outside.

11. According to the method described in claim 10, characterized in that, adjust the natural gas transportation volume of the natural gas pipeline (NG-3), and adjust the flow rates of the third branch (A-4) of the outlet pipeline of the air compressor (C01) and another branch line (NG-2) of the outlet pipeline of the spiral LNG vaporization coil 11, so as to ensure that the natural gas outlet temperature of the natural gas pipeline (NG-3) is 0 - 20 °C, the flue gas outlet temperature set on the flue gas outlet pipeline (A-7) is 20 - 40 °C, and the upper and lower pipe wall temperatures of the catalytic combustion reaction tube are 0 - 100 °C higher than the catalyst activation temperature.

12. According to the method described in claim 10, characterized in that, the temperature range of the liquefied natural gas fed from the liquefied natural gas pipeline is -170 - -140 °C, and the pressure range is 0.1 - 0.5 MPa.

Images