Fuel gas and air double-preheating device of petrochemical heating furnace
Through the petrochemical heating furnace fuel gas and air dual preheating device, the heat exchange between flue gas and fuel gas and air is used to solve the problem of low heat discharge efficiency of the heating furnace due to the heating furnace, achieving efficient heat recovery and equipment safety.
Patent Information
- Application Number
- CN202421331118.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-12
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-06-12
AI Technical Summary
The thermal efficiency of petrochemical heating furnaces has decreased due to flue gas heat exhaust, and the prior art is difficult to effectively reduce the smoke exhaust temperature to improve the furnace efficiency.
Design a petrochemical heating furnace fuel gas and air dual preheating device, through the combination of fuel gas heater, air preheater and flue gas heat exchanger, and use the circulation circuit of the flue gas heat exchange tube bundle and the fuel gas heat exchange tube bundle. Absorbs the heat of the flue gas and heat the fuel gas and air to reduce the smoke exhaust temperature.
The exhaust temperature of the heating furnace is minimized, the thermal efficiency is improved, and efficient heat transfer and separation between the flue gas and the combustion air is achieved through the heat pipe type, ensuring the safety and long life of the equipment.
Smart Images
Figure CN222256676U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of waste heat utilization of petrochemical heating furnaces, in particular to a flue gas waste heat recovery technology, specifically a fuel gas and air dual preheating device for a petrochemical heating furnace. Background Art
[0002] Heating furnaces are important process equipment in the production process of petrochemical enterprises and are also the main equipment for fuel consumption. The total energy consumption of petrochemical enterprises accounts for about 8% of the crude oil processing volume, of which the fuel energy consumption of heating furnaces accounts for 30-50% of the total energy consumption. Therefore, energy saving and consumption reduction of heating furnaces is an important topic of energy conservation work in petrochemical enterprises. Improving the thermal efficiency of heating furnaces is the key to achieving efficient use of fuel, reducing fuel consumption, reducing energy consumption and costs, and reducing carbon emissions.
[0003] According to the specific situation analysis of petrochemical heating furnaces and waste heat recovery systems, there are four main factors that affect the thermal efficiency of heating furnaces: 1) loss of mechanical incomplete combustion of fuel; 2) loss of chemical incomplete combustion of fuel; 3) heat dissipation loss of heating furnaces and waste heat recovery systems; 4) exhaust loss of heating furnaces. Among the above four influencing factors, due to the large amount of flue gas emitted by the heating furnace, the flue gas will carry a large amount of heat and be discharged into the atmosphere. The heat loss caused by flue gas emission accounts for about 60~70% of the heat loss of the heating furnace. Therefore, exhaust loss of the heating furnace is a key factor affecting the efficiency of the heating furnace.
[0004] According to the characteristics of the heating furnace, the factors affecting its smoke exhaust loss are mainly the following:
[0005] The excess air coefficient of fuel combustion is reflected in the oxygen content and amount of flue gas;
[0006] The problem of air leakage on the flue gas side of the heating furnace and waste heat recovery system will cause an increase in the amount of flue gas;
[0007] The temperature of the exhaust gas.
[0008] In terms of excess air coefficient control, on the basis of selecting qualified burners, the oxygen content in the flue gas can be controlled within an appropriate range (such as 2%~2.5%) through appropriate operating adjustments to ensure that the furnace efficiency is not reduced due to the increase in flue gas volume.
[0009] The problem of air leakage on the flue gas side of the hot furnace and waste heat recovery system can be eliminated or reduced through structural optimization and other means.
[0010] The most effective way to improve furnace efficiency is to lower the exhaust temperature and reduce exhaust heat loss. Therefore, in the heating furnace industry, people have been committed to improving the thermal efficiency of heating furnaces by lowering the exhaust temperature.
[0011] In the industry, the method of preheating the combustion air with the flue gas from the heating furnace is generally used to reduce the exhaust temperature and improve the thermal efficiency of the heating furnace.
[0012] In order to reduce the exhaust gas temperature to the maximum extent and improve the thermal efficiency of the heating furnace, it is necessary to introduce a new cold fluid on the basis of preheating the combustion air to further absorb the heat of the flue gas, so as to achieve the purpose of improving the furnace efficiency. If the new cold fluid uses low-temperature process materials, it is difficult to achieve due to the limitations of the process equipment conditions; while using fuel gas to absorb the heat of the flue gas is easy to achieve in the petrochemical heating furnace. In this way, through the dual preheating of fuel gas and air, the heat of the flue gas is fully absorbed, the flue gas temperature is reduced, and the purpose of maximizing the furnace efficiency is achieved. Utility Model Content
[0013] The utility model aims to solve the problem of reduced thermal efficiency of existing petrochemical combustion furnaces due to flue gas heat exhaust, and designs a petrochemical heating furnace fuel gas and air double preheating device which recovers flue gas heat by double preheating of petrochemical heating furnace fuel gas and combustion air, so as to reduce the exhaust gas temperature to the maximum extent and improve the thermal efficiency of the heating furnace.
[0014] The technical solution of the utility model is:
[0015] A fuel gas and air dual preheating device for a petrochemical heating furnace, characterized in that it comprises a fuel gas heater, an air preheater and a flue gas heat exchanger, wherein the fuel gas heater is provided with a fuel gas channel, the air preheater is provided with an air channel, and the flue gas heat exchanger is provided with a flue gas channel; a flue gas heat exchange tube bundle is installed at the flue gas inlet end of the flue gas heat exchanger, and the flue gas heat exchange tube bundle is connected to the upper header and the lower header at both ends of the fuel gas heat exchange tube bundle in the fuel gas heater through the upper header and the lower header connected to the two ends and the corresponding pipelines, and the flue gas heat exchange The medium in the tube bundle sends the heat of the absorbed flue gas into the fuel gas heat exchange tube bundle to heat the fuel gas. The medium in the fuel gas heat exchange tube bundle releases the heat and returns to the flue gas heat exchange tube bundle. This cycle realizes the cyclic heating of the fuel gas by the flue gas heat. The flue gas flowing through the flue gas heat exchange tube bundle at the inlet end of the flue gas heat exchanger flows into the lower end of the air heat pipe of the air preheater and heats the medium therein. The heated medium exchanges heat with the medium at the upper end of the air heat pipe and heats the air flowing through the air preheater.
[0016] The fuel gas heater adopts a split heat pipe heat exchanger type, which is composed of a flue gas heat exchanger, a fuel gas heat exchanger, and external connecting pipelines (rising pipe and downcomer) between the two devices.
[0017] The flue gas heat exchanger is composed of a shell and a flue gas heat exchange tube bundle; the fuel gas heat exchanger is composed of a shell and a fuel gas heat exchange tube bundle. The flue gas heat exchange tube bundle and the fuel gas heat exchange tube bundle are connected through a riser and a downcomer to form a circulation loop. The flue gas heat exchange tube bundle is arranged in the smoke channel, and the fuel gas heat exchange tube bundle is arranged in the fuel gas channel. The number of the flue gas heat exchange tube bundle and the fuel gas heat exchange tube bundle is set in at least one row, and each row of tube bundles is connected by a riser and a downcomer to form an independent circulation loop for each corresponding tube bundle. The loop system is filled with working fluid, and each circulation loop system works independently. Through the heat exchange tube bundle and the circulation loop, the vaporization heat absorption of the working fluid in the tube bundle on the smoke side and the condensation heat release of the working fluid in the tube bundle on the fuel gas side are realized, so that the heat from the smoke side is transferred to the fuel gas side.
[0018] Fins can be installed on the outside of the heat exchange tubes in the heat exchange tube bundle to enhance heat transfer and improve heat exchange effect. Flue gas heat exchangers and fuel gas heat exchangers can be flexibly arranged according to the site conditions to ensure the separation effect of flue gas and fuel gas, avoid leakage between the two, and can transfer heat over long distances, bringing greater flexibility to the planning and layout of the device.
[0019] Furthermore, the flue gas heat exchange tube bundle and the heating gas heat exchange tube bundle both include an upper header, a plurality of heat exchange tubes and a lower header. The upper header of the flue gas heat exchange tube bundle is connected to the upper header of the fuel gas heat exchange tube bundle through a riser, and the lower header of the flue gas heat exchange tube bundle is connected to the lower header of the fuel gas heat exchange tube bundle through a downcomer.
[0020] The high temperature section / low temperature section air preheater adopts an integral heat pipe heat exchanger, and the heat pipe element of the low temperature section air preheater adopts an anti-corrosion heat pipe to meet the needs of resisting low temperature flue gas acid dew point corrosion.
[0021] The high temperature section / low temperature section air preheater comprises a shell and a plurality of heat pipes, wherein the heat pipe comprises a heat pipe base tube, and the heat pipe base tube is divided into a flue gas side and an air side by a partition, wherein the flue gas side is located in the flue gas channel, and the air side is located in the air channel, and a working medium is arranged in the heat pipe base tube.
[0022] The heat pipe is a gravity heat pipe, including a heat pipe base tube, on which fins can be set to enhance the heat transfer effect; the heat pipe base tube is a closed cavity, a certain negative pressure is first drawn into the closed tube, and a working fluid is filled in. The heat on the flue gas side is quickly transferred to the air side through the working fluid in the heat pipe, completing the heat transfer to the gas to be heated, and the flue gas and air are separated from each other without leakage.
[0023] The utility model describes a petrochemical heating furnace fuel gas and air dual preheating device. The flue gas heat exchanger in the fuel gas heater can also be arranged between the high-temperature section air preheater and the low-temperature section air preheater. The specific setting position is determined according to factors such as flue gas temperature process parameters, site conditions, and on-site needs. The general principle is to enable the fuel gas heat exchange equipment to avoid the risk of low-temperature acid dew point corrosion and ensure the inherent safety of the equipment. At the same time, the temperature of the fuel gas heating meets the needs of stable operation of the burner.
[0024] Furthermore, in the petrochemical heating furnace fuel gas and air dual preheating device described in the utility model, the fuel gas heater can also adopt an integral heat pipe heat exchanger; the air preheater can also adopt a split heat pipe heat exchanger, and the specific setting plan is determined according to the site conditions and needs.
[0025] The beneficial effects of the utility model are as follows:
[0026] Through dual preheating of fuel gas and air, the exhaust temperature of the petrochemical heating furnace is further reduced, thereby maximizing the efficiency of the heating furnace.
[0027] The heat exchange equipment adopts the heat pipe type, which can effectively achieve the source separation and sealing effect between flue gas and combustion / air while realizing efficient heat transfer between flue gas and combustion / air, thus realizing the long life and intrinsic safety of the equipment, especially the safe operation of the fuel gas heater is guaranteed.
[0028] The low-temperature section air preheater module is set up separately and can be replaced flexibly, which greatly reduces the cost of equipment maintenance and replacement. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a schematic diagram of the layout scheme of the utility model.
[0030] Figure 2 It is a schematic diagram of the fuel gas heater of the utility model.
[0031] Figure 3 This is a schematic diagram of the heat exchange tube bundle circulation loop of the fuel gas heater of the utility model.
[0032] Figure 4 This is a schematic diagram of the high-temperature section heat pipe air preheater of the utility model.
[0033] Figure 5 This is a schematic diagram of the high-temperature section heat pipe of the utility model.
[0034] Figure 6 This is a schematic diagram of the low temperature section heat pipe air preheater of the utility model.
[0035] Figure 7 This is a schematic diagram of the low temperature section heat pipe of the utility model.
[0036] Figure 8 This is a schematic diagram of another arrangement scheme of the utility model.
[0037] In the figure:
[0038] 100, smoke channel; 200, air channel; 300, fuel gas channel;
[0039] 110. Flue gas heat exchanger; 120. High temperature section air preheater; 130. Low temperature section air preheater;
[0040] 103, rising pipe; 111, shell; 112, flue gas heat exchange tube bundle; 1121, upper header; 1122, heat exchange tube; 1123, lower header; 113, working medium;
[0041] 121 shell; 122, air heat pipe; 1221, working medium; 1222, base pipe; 1223, fin; 123, partition;
[0042] 131 shell; 132, anti-corrosion heat pipe; 1321, working medium; 1322, base pipe; 1323, fin; 133, partition;
[0043] 310, fuel gas heater; 301, downcomer; 311, shell; 312, fuel gas heat exchange tube bundle. DETAILED DESCRIPTION
[0044] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0045] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of implementation. The change or adjustment of their relative relationship should also be regarded as the scope of implementation of the utility model without substantial change of the technical content.
[0046] Embodiment 1.
[0047] like Figure 1 shown.
[0048] A fuel gas and air dual preheating device for a petrochemical heating furnace, comprising a fuel gas heater 310, an air preheater (composed of a high temperature section air preheater 120 and a low temperature section air preheater 130 connected in series) and a flue gas heat exchanger 110, wherein the fuel gas heater 310 is provided with a fuel gas channel 300, the air preheaters 120 and 130 are provided with air channels 200, and the flue gas heat exchanger 110 is provided with a flue gas channel 100; a flue gas heat exchange tube bundle 112 is installed at the flue gas inlet end of the flue gas heat exchanger 110, and the flue gas heat exchange tube bundle 112 is connected to the fuel gas heat exchange tube bundle 312 in the fuel gas heater 310 through an upper header 1121, a lower header 1123 and corresponding pipelines 103 and 301 connected to the two ends thereof The upper header 3121 and the lower header 3123 at both ends are connected, and the medium in the flue gas heat exchange tube bundle 112 sends the heat of the absorbed flue gas into the fuel gas heat exchange tube bundle 312 to heat the fuel gas. The medium in the fuel gas heat exchange tube bundle 312 releases the heat and returns to the flue gas heat exchange tube bundle 112, so that the cycle heats the fuel gas by the flue gas heat. The flue gas flowing through the flue gas heat exchange tube bundle 112 at the inlet end of the flue gas heat exchanger 110 flows into the lower end of the air heat pipe 122 of the air preheater 120, 130 and heats the medium therein. The heated medium exchanges heat with the medium at the upper end of the air heat pipe 122 and heats the air flowing through the air channel 200 of the air preheater.
[0049] See also Figures 1 to 3 The utility model provides a petrochemical heating furnace fuel gas and air dual preheating device, including a flue gas channel 100, an air channel 200, a fuel gas channel 300, a fuel gas heater 1000, a high temperature section air preheater 120, and a low temperature section air preheater 130. The above three heat exchange devices are arranged in sequence on the flue gas channel 100. Through this arrangement, the exhaust gas temperature of the heating furnace is reduced to the maximum extent.
[0050] The air preheater is divided into two modules, a high-temperature section and a low-temperature section. This is mainly because the low-temperature part of the air preheater operates in relatively harsh conditions of a low-temperature flue gas environment for a long time. To facilitate maintenance and replacement, a low-temperature section air preheater 130 module is specially set up, which can greatly reduce the cost of equipment maintenance and replacement.
[0051] The waste heat of the exhaust gas from the heating furnace is first cooled by heat exchange through the fuel gas heater 1000.
[0052] The fuel gas heater 1000 adopts a split type heat pipe heat exchanger, which is composed of a flue gas heat exchanger 110, a fuel gas heat exchanger 310, and external connecting pipelines (rising pipe 103, downcomer 301) between the two devices.
[0053] The flue gas heat exchanger 110 is composed of a shell 111 and a flue gas heat exchange tube bundle 112, and is installed on the flue gas channel 100; the fuel gas heat exchanger 310 is composed of a shell 311 and a fuel gas heat exchange tube bundle 312, and is installed on the fuel gas channel 100. The flue gas heat exchange tube bundle 112 includes an upper header 1121, a plurality of heat exchange tubes 1122, and a lower header 1123; the fuel gas heat exchange tube bundle 312 includes an upper header 3121, a plurality of heat exchange tubes 3122, and a lower header 3123. The flue gas heat exchange tube bundle 112 and the fuel gas heat exchange tube bundle 312 are connected through the riser 103 and the downcomer 301 to form a circulation loop. The number of the flue gas heat exchange tube bundle 112 and the fuel gas heat exchange tube bundle 312 can be one row or more rows, and each row of tube bundles is connected through the riser and the downcomer to form an independent circulation loop for each corresponding tube bundle. The loop system is filled with working medium 113, and each circulation loop system works independently. Through the heat exchange tube bundle and the circulation loop, the working medium in the flue gas side tube bundle absorbs heat through vaporization and the working medium in the fuel gas side tube bundle releases heat through condensation, thereby transferring heat from the flue gas side to the fuel gas side.
[0054] Fins can be provided on the outside of the heat exchange tubes of the heat exchange tube bundle to enhance heat transfer and improve the heat exchange effect. The flue gas heat exchanger 110 and the fuel gas heat exchanger 310 can be flexibly arranged according to the site conditions to ensure the separation effect of flue gas and fuel gas, avoid leakage between the two, and can transfer heat over a long distance, bringing greater flexibility to the planning and layout of the device.
[0055] See also Figures 1 to 7 The utility model provides a petrochemical heating furnace fuel gas and air dual preheating device, wherein an air preheater is arranged after the fuel gas heater 1000, and is divided into a high-temperature section air preheater 120 and a low-temperature section air preheater 130.
[0056] The high temperature section / low temperature section air preheater 120 / 130 both adopt an integral heat pipe heat exchanger, wherein the heat pipe element of the low temperature section air preheater 130 adopts an anti-corrosion heat pipe 132 to meet the needs of resisting low temperature flue gas acid dew point corrosion.
[0057] The high temperature section air preheater 120 includes a shell 121 and a plurality of heat pipes 122 . The heat pipe 122 includes a heat pipe base tube 1222 which is divided into a flue gas side and an air side by a partition 123 . A working medium 1221 is arranged in the heat pipe base tube 1222 .
[0058] The low-temperature section air preheater 130 includes a shell 131 and a plurality of anti-corrosion heat pipes 132 . The anti-corrosion heat pipe 132 includes a heat pipe base tube 1322 , which is separated into a flue gas side and an air side by a partition 133 . A working medium 1321 is arranged in the heat pipe base tube 1322 .
[0059] The heat pipe is a gravity heat pipe, and fins can be set on the heat pipe base to enhance the heat transfer effect. The heat on the flue gas side is quickly transferred to the air side through the working fluid in the heat pipe, completing the heat transfer to the gas that needs to be heated, and the flue gas and air are separated from each other without leakage.
[0060] The base pipe 1322 and fins 1323 on the flue gas side of the anti-corrosion heat pipe 132 can be made of highly anti-corrosion materials, or ordinary carbon steel with an anti-corrosion coating to meet the anti-corrosion needs of the heat pipe in a low-temperature flue gas environment.
[0061] Embodiment 2.
[0062] See also Figure 8 The utility model describes a petrochemical heating furnace fuel gas and air dual preheating device. The flue gas heat exchanger 110 in the fuel gas heater 1000 can also be arranged between the high-temperature section air preheater 120 and the low-temperature section air preheater 130. The specific setting position is determined according to factors such as flue gas temperature process parameters, site conditions, and on-site requirements. The general principle is to avoid the risk of low-temperature acid dew point corrosion in the fuel gas heat exchange equipment to ensure the inherent safety of the equipment. At the same time, the temperature of the fuel gas heating meets the needs of stable operation of the burner.
[0063] Embodiment three.
[0064] The utility model describes a petrochemical heating furnace fuel gas and air dual preheating device, the fuel gas heater 1000 can also adopt an integral heat pipe heat exchanger; the air preheater (high temperature section air preheater 120, low temperature section air preheater 130) can also adopt a split heat pipe heat exchanger, and the specific setting plan is determined according to the site conditions and needs.
[0065] See the schematic diagram of split and integral heat pipe heat exchanger for details. Figures 2 to 7 .
[0066] The above embodiments are only preferred implementation modes of the present utility model. It should be pointed out that ordinary technicians in this technical field can make several improvements and equivalent substitutions without departing from the principles of the present utility model. These technical solutions after improvements and equivalent substitutions of the claims of the present utility model all fall within the protection scope of the present utility model.
[0067] The parts not involved in the present invention are the same as the prior art or can be implemented by using the prior art.
Claims
1. A petrochemical heating furnace fuel gas and air dual preheating device, characterized in that : It includes a fuel gas heater, an air preheater and a flue gas heat exchanger. The fuel gas heater is provided with a fuel gas channel, the air preheater is provided with an air channel, and the flue gas heat exchanger is provided with a flue gas channel; a flue gas heat exchange tube bundle is installed at the flue gas inlet end of the flue gas heat exchanger, and the flue gas heat exchange tube bundle is connected with the upper header and the lower header at both ends of the fuel gas heat exchange tube bundle in the fuel gas heater through the upper header and the lower header connected to the two ends and the corresponding pipelines. The medium in the flue gas heat exchange tube bundle sends the heat of the smoke absorbed into the fuel gas heat exchange tube bundle to heat the fuel gas. The medium in the fuel gas heat exchange tube bundle releases the heat and returns to the flue gas heat exchange tube bundle. In this way, the heat of the smoke gas is circulated to heat the fuel gas; the smoke flowing through the smoke gas heat exchange tube bundle at the inlet end of the smoke gas heat exchanger flows into the lower end of the air heat pipe of the air preheater and heats the medium therein. The heated medium exchanges heat with the medium at the upper end of the air heat pipe and heats the air flowing through the air preheater.
2. The dual preheating device for fuel gas and air of a petrochemical heating furnace according to claim 1 is characterized in that : The air preheater is composed of a high-temperature section air preheater and a low-temperature section air preheater connected in series, and the air heat pipe in the low-temperature section air preheater is an anti-corrosion heat pipe.
3. The fuel gas and air dual preheating device for petrochemical heating furnace according to claim 1 is characterized in that :The flue gas heat exchanger is composed of a shell and a flue gas heat exchange tube bundle; the fuel gas heat exchanger is composed of a shell and a fuel gas heat exchange tube bundle; the flue gas heat exchange tube bundle and the fuel gas heat exchange tube bundle are connected through an ascending tube and a descending tube to form a circulation loop; the flue gas heat exchange tube bundle is arranged in the flue gas channel, and the fuel gas heat exchange tube bundle is arranged in the fuel gas channel; the number of the flue gas heat exchange tube bundle and the fuel gas heat exchange tube bundle is at least one row, and each row of tube bundles is connected through an ascending tube and a descending tube to form an independent circulation loop for each corresponding tube bundle; the loop system is filled with working fluid, and each circulation loop system works independently. Through the heat exchange tube bundle and the circulation loop, the vaporization heat absorption of the working fluid in the tube bundle on the flue gas side and the condensation heat release of the working fluid in the tube bundle on the fuel gas side are realized, so that the heat from the flue gas side is transferred to the fuel gas side.
4. The fuel gas and air dual preheating device for petrochemical heating furnace according to claim 1 is characterized in that The heat exchange tubes in the fuel gas heat exchange tube bundle are provided with fins for enhancing heat transfer on the outside.
5. The dual preheating device for fuel gas and air of a petrochemical heating furnace according to claim 1 is characterized in that The flue gas heat exchange tube bundle and the heating gas heat exchange tube bundle both include an upper header, a plurality of heat exchange tubes and a lower header. The upper header of the flue gas heat exchange tube bundle is connected to the upper header of the fuel gas heat exchange tube bundle through a riser, and the lower header of the flue gas heat exchange tube bundle is connected to the lower header of the fuel gas heat exchange tube bundle through a downcomer.
6. The dual preheating device for fuel gas and air of a petrochemical heating furnace according to claim 2 is characterized in that : The high temperature section air preheater and the low temperature section air preheater both adopt integral heat pipe heat exchangers.
7. The fuel gas and air dual preheating device for petrochemical heating furnace according to claim 2 is characterized in that The high-temperature section air preheater and the low-temperature section air preheater include a shell and a plurality of heat pipes. The heat pipes include heat pipe base tubes. The heat pipe base tubes are divided into a flue gas side and an air side by a partition. The flue gas side is located in the flue gas channel, and the air side is located in the air channel. A working medium is arranged in the heat pipe base tube.
8. The fuel gas and air dual preheating device for petrochemical heating furnace according to claim 7 is characterized in that The heat pipe is a gravity heat pipe, including a heat pipe base tube, on which fins are arranged to enhance the heat transfer effect; the heat pipe base tube is a closed cavity, in which a certain negative pressure is first drawn and filled with a working fluid; the heat on the flue gas side is quickly transferred to the air side through the working fluid in the heat pipe, completing the heat transfer to the gas to be heated, and the flue gas and air are separated from each other without leakage.
9. The fuel gas and air dual preheating device for petrochemical heating furnace according to claim 1 is characterized in that :The flue gas heat exchanger is arranged between the high temperature section air preheater and the low temperature section air preheater.
10. The fuel gas and air dual preheating device for petrochemical heating furnace according to claim 1 is characterized in that : The fuel gas heater adopts an integral heat pipe heat exchanger; the air preheater adopts a split heat pipe heat exchanger.