Ascending pipe subsequent raw gas waste heat recovery equipment and waste heat recovery method thereof

Abstract

The invention discloses ascending pipe subsequent raw gas waste heat recovery equipment. The high-temperature gas collecting pipe is connected to the outlet end of the bridge pipe; the pi-shaped pipe is connected to a gas outlet in the top end of the high-temperature gas collecting pipe; the low-temperature gas collecting pipe is connected to the outlet end of the pi-shaped pipe; the heavy oil tank, the high-temperature oil pump and the heat exchange device are sequentially connected to the lower end of the high-temperature gas collecting pipe; the pi-shaped pipe comprises a first vertical pipe, a horizontal pipe and a second vertical pipe which are connected in sequence, the first vertical pipe extends upwards from the top end of the high-temperature gas collecting pipe, and a coal tar spraying head is arranged in the first vertical pipe; the high-temperature oil pump is used for conveying coal tar sprayed by the coal tar spraying head to the heat exchange device through the high-temperature gas collecting pipe and the heavy oil tank for waste heat recovery. Therefore, coal tar is sprayed in the first vertical pipe through the coal tar spraying head, so that the sprayed coal tar exchanges heat with raw gas, passes through the high-temperature gas collecting pipe, the heavy oil tank and the high-temperature oil pump and then enters the heat exchange device, and heat recovery can be carried out.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical industry, energy saving and environmental protection technical field, and particularly relates to a rising pipe subsequent raw coal gas waste heat recovery equipment and process. BACKGROUND

[0002] In the production process of coke oven, a large amount of raw coal gas is produced, and the raw coal gas contains organic compounds such as tar, benzene, naphthalene and the like. The temperature of the raw coal gas is 650-750 DEG C, and the current method for recovering heat energy is mainly to change the ordinary rising pipe into a rising pipe heat exchanger. The raw coal gas is usually reduced to 500 DEG C to recover part of the heat energy. If the temperature of the raw coal gas continues to drop, the tar will condense and block the rising pipe. Therefore, the recovery efficiency of the recovered heat energy in the current rising pipe waste heat utilization project is only 30-35%, ammonia water is sprayed at the rising pipe subsequent bridge pipe, the ammonia water is evaporated, absorbs the heat energy of the raw coal gas, and the temperature of the raw coal gas is reduced to 85 DEG C, and the ammonia water becomes steam and enters the raw coal gas. The raw coal gas enters the primary cooler, and the circulating cooling water in the primary cooler reduces the temperature of the raw coal gas to 25 DEG C, and the moisture in the raw coal gas is condensed and discharged. The primary cooler uses circulating cooling water, and needs a cooling water tower fan to operate for cooling, consumes power, and increases the power cost.

[0003] Spraying ammonia water has negative effects in the actual production of coking. Since the ammonia water is recycled, the concentration of ammonium salt in the ammonia water is continuously accumulated, the tar and ammonia water are mixed together in the gas collecting pipe, and under the action of the coal powder and coke powder, a tar water emulsion is formed, and the salt also enters the tar. When the subsequent tar distillation extracts various valuable oil products, it is necessary to first break the emulsion, then separate the tar and ammonia water, then add sodium carbonate to separate the ammonia, and cause sodium chloride to enter the tar. It is necessary to control the amount of sodium carbonate added to prevent the salt content from being too high. The rising pipe subsequent ammonia water spraying process not only wastes the heat energy of the raw coal gas, but also causes a part of the salt to enter the tar due to the recycling of the ammonia water, thereby reducing the quality of the tar. At present, coking enterprises generally hope to update the process, recover the heat energy below 500 DEG C of the raw coal gas, and reduce the use of ammonia water.

[0004] Qingdao University of Science and Technology's patented technology, "Raw Gas Heat Recovery System and Method Based on Scrubbing Distillation," has application publication number CN 105779027 A. Inventors Chen Guanghui and Wang Weiwen proposed a scrubbing distillation tower process, utilizing a 20-meter-tall distillation tower with trays at varying heights to distill and separate light components and recover the heat energy of the raw gas. Due to the high concentration of tar components, the distillation tower's height remained 20 meters, and it could not be lowered. Chen Guanghui and Wang Weiwen discussed the issue with the author and, under their guidance, conducted an on-site inspection of the coking plant. During their inspection of the coking oven roof, they discovered that the scrubbing distillation tower, the patented technology from Qingdao University of Science and Technology, was too tall to be installed directly on the coking oven's existing equipment, including the riser and gas headers. This limited Qingdao University of Science and Technology's patented technology to theoretical standards and could not be applied in coking ovens. In summary, coking plants need to reduce costs and improve energy efficiency, and they intend to further recover heat energy from raw gas below 500°C after the riser. When the raw gas temperature drops below 380°C, a large amount of tar will condense and precipitate. To prevent the tar from accumulating on the inner surface of the steel pipe, the new equipment must also solve this problem. Summary of the Invention

[0005] The purpose of the present invention is to provide a riser subsequent raw gas waste heat recovery device and a waste heat recovery method, which realizes the riser subsequent raw gas heat recovery through coal tar spraying and recovery, thereby improving the heat energy recovery rate.

[0006] To achieve the above-mentioned purpose, the present invention provides a riser subsequent raw gas waste heat recovery device, which includes a bridge pipe connected to the riser, a high-temperature gas collecting pipe connected to the outlet end of the bridge pipe, a π-type pipe connected to the gas outlet at the top of the high-temperature gas collecting pipe, a low-temperature gas collecting pipe connected to the outlet end of the π-type pipe, a heavy oil tank connected to the lower end of the high-temperature gas collecting pipe in sequence, a high-temperature oil pump and a heat exchange device; wherein, the π-type pipe includes a first vertical pipe, a horizontal pipe and a second vertical pipe connected in sequence, the first vertical pipe extends upward from the top of the high-temperature gas collecting pipe, and a coal tar spray head is provided in the first vertical pipe, and the high-temperature oil pump is used to transport the coal tar sprayed from the coal tar spray head through the high-temperature gas collecting pipe and the heavy oil tank to the heat exchange device for waste heat recovery.

[0007] Furthermore, it also includes a heat exchanger arranged in the second vertical pipe.

[0008] Furthermore, the bottom end of the second vertical pipe is connected to the top of the low-temperature gas collecting pipe, and the subsequent raw gas waste heat recovery equipment of the riser also includes a first oil washing spray head arranged in the second vertical pipe, and the heat exchanger is located below the first oil washing spray head, and the first oil washing spray head is arranged at the top of the second vertical pipe.

[0009] Further, the low-temperature gas collecting pipe is provided with a plurality of second oil washing spray heads at the top, the low-temperature gas collecting pipe is made of stainless steel, and the outer surface is provided with an aluminum silicate fiber heat preservation layer.

[0010] Further, the π-shaped pipe is a composite steel pipe, the inner surface is a ceramic non-stick coating layer, the outer surface of the π-shaped pipe is a heat preservation layer, the non-stick coating layer is a ceramic non-stick coating layer, and the outer heat preservation layer is an aerogel heat preservation layer.

[0011] Further, the bridge pipe is a downwardly extending arc-shaped elbow pipe, the high-temperature gas collecting pipe is arranged below the bridge pipe, a coal tar spraying head for spraying coal tar is arranged in the bridge pipe, so that the coal tar sprayed by the coal tar spraying head can enter the high-temperature gas collecting pipe, the coal tar spraying head in the first vertical pipe is referred to as a second coal tar spraying head.

[0012] Further, the bridge pipe is a downwardly extending arc-shaped elbow pipe, the high-temperature gas collecting pipe is arranged below the bridge pipe, a coal tar spraying head for spraying coal tar is arranged in the bridge pipe, so that the coal tar sprayed by the coal tar spraying head can enter the high-temperature gas collecting pipe, the coal tar spraying head in the first vertical pipe is referred to as a second coal tar spraying head.

[0013] Further, the high-temperature gas collecting pipe adopts a double-layer steel pipe structure, the inner layer steel pipe of the high-temperature gas collecting pipe is made of 304, 316, 309 or 310S material, and the outer layer steel pipe of the high-temperature gas collecting pipe is made of carbon steel or stainless steel material.

[0014] Further, the inner layer steel pipe and the outer layer steel pipe of the double-layer steel pipe structure are supported by a steel structure, and an aluminum silicate ceramic fiber blanket is filled between the inner layer steel pipe and the outer layer steel pipe.

[0015] Further, the inner layer structure of the heavy oil tank adopts a double-layer structure, the inner layer structure of the heavy oil tank is made of 304, 316, 309 or 310S material, and the outer layer structure of the heavy oil tank is made of carbon steel or stainless steel material.

[0016] Further, the inner layer structure and the outer layer structure of the heavy oil tank are supported by a steel structure, and a heat preservation material, i.e., an aluminum silicate ceramic fiber blanket, is filled between the inner layer structure and the outer layer structure.

[0017] Further, the heat exchange device is a heat exchange boiler, and the outlet of the high-temperature oil pump is connected to the inlet of the heat exchange boiler through a high-temperature oil pipeline.

[0018] Further, it also comprises a gas-liquid separator, a primary cooler, a rich oil storage tank, a rich oil pump, a rich oil heater and a distillation tower; the inlet of the gas-liquid separator is connected with the outlet of the low-temperature gas collecting pipe, the upper end outlet of the gas-liquid separator is connected with the primary cooler upwardly; the bottom end outlet of the gas-liquid separator is connected with the inlet of the rich oil storage tank, the outlet of the rich oil storage tank is connected with the inlet of the rich oil pump, the outlet of the rich oil pump is connected with the inlet of the bottom end of the rich oil heater, and the upper end outlet of the rich oil heater is connected with the distillation tower.

[0019] Further, it also comprises a tar precipitation tank connected with the bottom end outlet of the heat exchange boiler and a tar storage tank connected with the tar precipitation tank.

[0020] To achieve the above-mentioned purpose, the application further provides a waste heat recovery method using the rising pipe subsequent coke oven gas waste heat recovery equipment, which comprises the following steps: The coal tar is sprayed through a coal tar spraying head in the first vertical pipe of the π-shaped pipe, so that the sprayed coal tar exchanges heat with the coke oven gas entering the first vertical pipe, and then enters the heat exchange device through the high-temperature gas collecting pipe, the heavy oil tank and the high-temperature oil pump for heat recovery.

[0021] To achieve the above-mentioned purpose, the application further provides a waste heat recovery method using the rising pipe subsequent coke oven gas waste heat recovery equipment, which comprises the following steps: The coal tar is sprayed through a coal tar spraying head in the first vertical pipe of the π-shaped pipe, so that the sprayed coal tar exchanges heat with the coke oven gas entering the first vertical pipe, and then enters the heat exchange device through the high-temperature gas collecting pipe, the heavy oil tank and the high-temperature oil pump for heat recovery. The coke oven gas after the first vertical pipe continues to enter the second vertical pipe, exchanges heat with the heat exchanger in the second vertical pipe, and then recovers heat through the heat exchanger again.

[0022] The application has the following beneficial effects: Firstly, the rising pipe of the coke oven can only reduce the coke oven gas to 500 DEG C, and the application can further recover the heat energy below 500 DEG C of the coke oven gas, reduce the load of the primary cooler, produce steam for use and improve the economic benefit.

[0023] Secondly, the coal tar is sprayed through a coal tar spraying head in the first vertical pipe, the coal tar and the coke oven gas directly exchange heat, the heat exchange efficiency is high, and the coal tar washing washes out the coal tar in the coke oven gas and flows into the high-temperature gas collecting pipe downwardly, so that the problem of pipe blockage caused by the coal tar precipitation below 500 DEG C is solved.

[0024] Third, the coal tar is sprayed through the coal tar spray head in the first vertical pipe without spraying ammonia water, so that the water content of the coal tar is greatly reduced and the quality of the coal tar is improved. In the previous process, spraying ammonia water causes the water content of the coal tar to be 4%, and in the subsequent production of various components of the coal tar, dehydration is required before distillation. Since the water content of the coal tar is low in the process, the energy consumption in the subsequent production can be reduced.

[0025] Fourth, in the traditional process of spraying ammonia water through the bridge pipe, the accumulation of ammonium salt in the circulating ammonia water causes the salt content of the coal tar to increase, and sodium carbonate needs to be added in the subsequent production to separate ammonia, and the salt is finally present in the coal tar in the form of sodium chloride. In the present application, the ammonia water spraying device is cancelled, the salt content of the coal tar is low, the quality of the coal tar is further improved, the selling price of the recovered coal tar is improved, and the economic benefit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structural schematic view of the subsequent raw gas waste heat recovery equipment of the rising pipe of the present application; Figure 2 is a structural schematic view of the subsequent process of the oil-rich storage tank of the present application; Among them, 1, rising pipe; 2, high temperature valve; 3, steam spray head; 4, first coal tar spray head; 5, first vertical pipe; 6, second vertical pipe; 7, high temperature gas collecting pipe; 8, heavy oil tank; 9, high temperature oil pump; 10, high temperature oil pipeline; 11, low temperature gas collecting pipe; 12, second coal tar spray head; 13, horizontal pipe; 14, π type pipe elbow; 15, spray pipe; 16, second oil washing spray head; 17, bridge pipe; 18, first oil washing spray head; 19, gas-liquid separator; 20, primary cooler; 21, oil-rich storage tank; 22, heat exchange boiler; 23, tar precipitation tank; 24, oil-rich pump; 25, oil-rich heater; 26, distillation column; 61, heat exchanger. DETAILED DESCRIPTION

[0027] In order to better explain the present application, the technical solutions and effects of the present application are described in detail in the specific embodiments combined with the drawings.

[0028] As shown in Figure 1 and Figure 2 , the present embodiment provides a rising pipe subsequent raw gas waste heat recovery equipment, which comprises a bridge pipe 17, a high temperature gas collecting pipe 7, a low temperature gas collecting pipe 11, a π type pipe, a first coal tar spray head 4, a second coal tar spray head 12, a heavy oil tank 8, a high temperature oil pump 9, a high temperature oil pipeline 10, a heat exchange boiler 22 and a tar precipitation tank 23.

[0029] One end of the bridge pipe 17 is connected with the riser 1, and the other end of the bridge pipe 17 is connected with the inlet of the high-temperature gas collecting pipe 7. The bridge pipe 17 is an arc-shaped downwardly extending elbow pipe. The high-temperature gas collecting pipe 7 is arranged below the bridge pipe 17 and is horizontally arranged to facilitate connection with multiple bridge pipes 17. The first coal tar spray head 4 is arranged in the bridge pipe 17. When the coal tar is sprayed, the sprayed coal tar can smoothly enter the high-temperature gas collecting pipe 7 after heat exchange with the raw coal gas entering the bridge pipe 17.

[0030] The two ends of the π-shaped pipe are respectively connected with the top end of the high-temperature gas collecting pipe 7 and the top end of the low-temperature gas collecting pipe 11 and are arranged above the high-temperature gas collecting pipe 7 and the low-temperature gas collecting pipe 11. The second coal tar spray head 12 is arranged in the π-shaped pipe.

[0031] The bottom end oil outlet of the high-temperature gas collecting pipe 7 is connected with the inlet of the heavy oil tank 8. The outlet of the heavy oil tank 8 is connected with the inlet of the high-temperature oil pump 9. The outlet of the high-temperature oil pump 9 is connected with the inlet of the heat exchange boiler 22 through the high-temperature oil pipeline 10. The bottom end outlet of the heat exchange boiler 22 is connected with the inlet of the tar precipitation tank 23. The heavy oil tank 8 is used for collecting the high-temperature coal tar. The high-temperature oil pump 9 sends the incoming coal tar into the heat exchange boiler 22 through the high-temperature oil pipeline 10 to exchange heat and generate steam. The steam is recycled and utilized.

[0032] After the heavy oil leaves the boiler, the temperature is reduced to 80℃ and enters the tar precipitation tank 23. The coal powder and coke powder in the heavy oil are separated out by using the principle of gravity precipitation. The remaining high-quality heavy oil enters the tar storage tank (not shown in the figure) for storage. The setting of the heavy oil tank 8 can ensure the stable inlet flow of the high-temperature oil pump 9. In the embodiment, the first coal tar spray head 4 and the second coal tar spray head 12 are necessarily connected with a coal tar supply source through an oil supply pipeline. The coal tar supply source can be connected with the tar storage tank or other coal tar supply sources.

[0033] In the embodiment, the π-shaped pipe includes a first vertical pipe 5, a horizontal pipe 13 and a second vertical pipe 6 connected in sequence. The π-shaped pipe has a π-shaped structure as a whole. The horizontal pipe 13 is located above the first vertical pipe 5 and the second vertical pipe 6. The horizontal pipe 13 is connected with the first vertical pipe 5 and the second vertical pipe 6 through a π-shaped pipe elbow 14, respectively.

[0034] The bottom end of the first vertical pipe 5 is connected to the top of the high-temperature gas collecting pipe 7 and extends vertically upward from the top of the high-temperature gas collecting pipe 7. The bottom end of the second vertical pipe 6 is connected to the top of the low-temperature gas collecting pipe 11 and extends vertically upward from the top of the low-temperature gas collecting pipe 11. The first vertical pipe 5 is a heavy oil spraying vertical pipe. The second coal tar spray head 12 is arranged at the top of the first vertical pipe 5 and has an empty tower structure. The second coal tar spray head 12 in the first vertical pipe 5 sprays coal tar transported by the spray pipe 15. The sprayed coal tar not only exchanges heat with the raw gas entering the first vertical pipe 5, but also acts as a wash, causing the raw gas entering the first vertical pipe 5 to precipitate coal tar. After the coal tar is precipitated, it is flushed downward by the sprayed coal tar into the high-temperature gas collecting pipe 7. Then, after passing through the heavy oil tank 8 and the high-temperature oil pump 9, it enters the heat exchange boiler 22 for heat exchange, generating steam, which is then recycled.

[0035] The π-shaped tube is a composite steel tube, and the inner surface of the π-shaped tube is a ceramic non-stick coating to prevent coal tar from accumulating on the inner surface of the steel tube; the outer surface of the π-shaped tube is an aerogel high-efficiency thermal insulation layer to prevent heat loss; the raw gas in the first vertical pipe 5 is cooled by the coal tar sprayed by the second coal tar spray head 12, and a large amount of coal tar carried therein is precipitated; the coal tar sprayed by the second coal tar spray head 12 and the condensed coal tar flow downward together, enter the high-temperature gas collecting pipe 7, and after mixing with the coal tar, enter the heavy oil tank 8, and are pumped out together by the high-temperature oil pump 9, thus solving the problem of coal tar precipitation and recovery.

[0036] The second vertical pipe 6 is a wash oil spray heat exchange pipe, and a heat exchanger 61 is provided inside the second vertical pipe 6. The heat exchanger 61 can adopt several types of tubular heat exchangers such as horizontal tube heat exchange pipes, coil heat exchange pipes, and vertical tube heat exchangers. In this embodiment, coil heat exchange pipes are preferred; water flows in the coil heat exchange pipes to cool the raw gas and recover the heat of the raw gas flowing through, specifically to generate steam for output utilization.

[0037] A first oil washing spray head 18 is also provided at the top of the second vertical pipe 6. The light oil carried in the raw gas is washed through the first oil washing spray head 18 to recover the light components (including, for example, naphthalene and phenol light oil components). The raw gas, washing oil and light components enter the low-temperature gas collecting pipe 11 together. The low-temperature environment is conducive to the absorption of light components.

[0038] In addition, the device also includes a gas-liquid separator 19, a primary cooler 20, an oil-rich storage tank 21, an oil-rich pump 24, an oil-rich heater 25 and a distillation tower 26; the inlet of the gas-liquid separator 19 is connected to the outlet of the low-temperature gas collecting pipe 11, and the upper end outlet of the gas-liquid separator 19 is upwardly connected to the primary cooler 20; the bottom end outlet of the gas-liquid separator 19 is connected to the inlet of the oil-rich storage tank 21, the outlet of the oil-rich storage tank 21 is connected to the inlet of the oil-rich pump 24, the outlet of the oil-rich pump 24 is connected to the bottom end inlet of the oil-rich heater 25, and the upper end outlet of the oil-rich heater 25 is connected to the distillation tower 26.

[0039] After the raw gas, wash oil and light components enter the low temperature gas collecting pipe 11 together, the rich wash oil (after the wash oil recovers naphthalene, phenol and other light oil components, it is called rich wash oil) flows below the low temperature gas collecting pipe 11, and the raw gas flows above the low temperature gas collecting pipe 11; the low temperature gas collecting pipe 11 is made of stainless steel, and the outer surface is insulated by aluminum silicate fiber; the top of the low temperature gas collecting pipe 11 is provided with 10 second wash oil spray heads 16, which can further spray and cool when the temperature of the raw gas is higher than 85℃; the temperature of the raw gas is further reduced to 85℃, and after separation by the gas-liquid separator 19, it enters the primary cooler 20 and is cooled to 25℃, and then is output for subsequent conventional processes; the rich wash oil at 85℃ is separated by the gas-liquid separator 19 and enters the rich oil storage tank 21, and is sent to the rich oil heater 25 by the rich oil pump 24 for heating, and then enters the distillation column 26 to distill naphthalene, phenol and light oil. The oil below the distillation column 26 is poor wash oil, which is cooled by the heat exchanger and then enters the wash oil storage tank, and then is transported back to the second vertical pipe 6 and the low temperature gas collecting pipe for further spray cooling.

[0040] As a preferred embodiment, the heavy oil tank 8 adopts a double-layer structure, the inner layer structure is made of 304, 316, 309 or 310S material, has the effect of high temperature resistance and corrosion resistance, and the preferred material of the embodiment is 316; the outer layer structure is made of carbon steel or stainless steel material, and the preferred material of the embodiment is stainless steel; the inner layer structure and the outer layer structure of the double-layer structure are supported by a steel structure, and are filled with insulation materials such as aluminum silicate ceramic fiber blanket, which greatly reduces heat loss.

[0041] The high temperature gas collecting pipe 7 adopts a double-layer steel pipe structure, the inner layer steel pipe is made of 304, 316, 309 or 310S material, has the effect of high temperature resistance and corrosion resistance, and the preferred steel of the embodiment is 310S; the outer layer steel pipe can be made of carbon steel or stainless steel material, and the preferred material of the embodiment is 304 stainless steel; the inner layer and the outer layer of the double-layer steel pipe structure are supported by a steel structure, and are filled with aluminum silicate fiber blanket, which greatly reduces heat loss. The traditional gas collecting pipe only has a single layer of steel plate, and the heat loss accounts for 10% of the total heat. The double-layer insulation structure is beneficial to reduce heat loss.

[0042] The high temperature oil pump 9 and the high temperature oil pipeline 10 are located on the right side of the high temperature gas collecting pipe 7. The material of the high temperature oil pipeline 10 is 316 stainless steel, the outer surface is insulated, the insulation material is selected from aluminum silicate fiber blanket, the outer surface of the insulation material is wrapped with an insulation outer skin, and the insulation outer skin is made of aluminum skin.

[0043] In addition, the high-temperature valve 2 is arranged on the bridge pipe 17, the material of the high-temperature valve 2 is heat-resistant steel, the high-temperature valve 2 can adopt a gate valve, a ball valve, a butterfly valve or a flap valve, and the butterfly valve is preferred in the embodiment. The high-temperature valve 2 plays a role of isolation, in the later period of production of the carbonization chamber, when the rising pipe 1 is opened for burning, the high-temperature valve 2 is closed, so as to prevent air from entering the high-temperature gas collecting pipe 7, and also prevent the raw coal gas from being discharged from the high-temperature gas collecting pipe 7; when the coal is loaded, the high-temperature valve 2 is opened, and the raw coal gas enters the high-temperature gas collecting pipe 7 from the rising pipe 1.

[0044] The steam nozzle 3 is further arranged in the bridge pipe 17, and is used for high-pressure spraying during the loading of the coal, so as to form a negative pressure and suck the raw coal gas into the high-temperature gas collecting pipe 7.

[0045] The high-temperature valve 2 is arranged close to the inlet end of the bridge pipe 17, so as to connect or disconnect the rising pipe 1 and the bridge pipe 17, and the steam nozzle 3 is arranged between the high-temperature valve 2 and the first coal tar spraying head 4. The high-temperature gas collecting pipe 7 is connected with the heavy oil tank 8, the high-temperature oil pump 9 and the high-temperature oil pipeline 10, so as to deliver the high-temperature coal tar to the heat exchange boiler 22 to produce steam.

[0046] The embodiment further discloses a process using the above device, and the process is specifically as follows. The raw coal gas enters the bridge pipe 17 through the rising pipe 1 of the coke oven, the first coal tar spraying head 4 sprays the coal tar in the bridge pipe 17, so as to reduce the temperature of the raw coal gas to below 300 DEG C, and the heavy coal tar in the raw coal gas is condensed. The raw coal gas and the coal tar all enter the high-temperature gas collecting pipe 7; The coal tar flows below the high-temperature gas collecting pipe, and the raw coal gas flows above the high-temperature gas collecting pipe. The heavy coal tar at 300 DEG C flows into the heavy oil tank 8 through the pipeline below the high-temperature gas collecting pipe 7, is sent into the heat exchange boiler 22 through the high-temperature oil pump 9, steam is produced, and is output for utilization, so that the first waste heat recovery of the raw coal gas in the rising pipe 1 is formed. After the heat exchange of the high-temperature coal tar, the temperature is reduced to below 80 DEG C, the coal tar enters the subsequent coal tar precipitation tank 23 to separate the coal tar residue, and the coal tar enters the coal tar storage tank; The raw coal gas at 300 DEG C enters the π-shaped pipe through the upper end gas outlet of the high-temperature gas collecting pipe 7, the second coal tar spraying head 12 in the first vertical pipe 5 sprays the coal tar, so as to reduce the temperature of the raw coal gas to 230 DEG C, and the coal tar and the raw coal gas are countercurrently heat exchanged. After the coal tar carried by the raw coal gas is separated out, the coal tar is washed away by the sprayed coal tar, and then enters the high-temperature gas collecting pipe 7 downward, and is mixed with the coal tar in the high-temperature gas collecting pipe 7, and then flows into the heavy oil tank 8, and then is extracted by the high-temperature oil pump 9 and is sent into the heat exchange boiler 22 to produce steam, so that the waste heat recovery of the raw coal gas in the rising pipe 1 is formed again; The raw coal gas continues to enter the second vertical pipe 6, and the heat exchanger 61 inside the second vertical pipe 6 has a plurality of groups of heat exchange pipes, water flows in the pipes to recover the heat of the raw coal gas flowing through and generate steam, which is output for use, thus forming the subsequent waste heat recovery of the raw coal gas after the rising pipe 1 again; Further, in the embodiment, the first oil washing spray head 18 in the second vertical pipe 6 sprays oil washing to recover light components including naphthalene, phenol, light oil and the like; since the light oil is attached to the surface of the heat exchange pipe during the third heat recovery, the oil washing can recover the light oil on the surface of the heat exchange pipe to form rich oil washing, which is together input into the low-temperature gas collecting pipe 11, and the temperature of the raw coal gas is further reduced to 85°C; after the raw coal gas and the light components are separated through the gas-liquid separator 19, the raw coal gas enters the primary cooler 20 to complete cooling, and is output after being cooled to 25°C; the rich oil washing flows into the rich oil storage tank 21, enters the rich oil heater 25 through the rich oil pump 24 for heating, and after the rich oil washing is heated, enters the subsequent distillation tower 26 to extract light components such as naphthalene, phenol and light oil, and the rich oil washing becomes lean oil washing. After the lean oil washing is cooled by the heat exchanger, it is returned to the first oil washing spray head 18 of the second vertical pipe 6 to continue to spray and cool.

[0047] Application Example One: A coking enterprise with an annual output of 1.2 million tons of coke. The raw coal gas quantity is 78,000 Nm3 / hour, and the gas contains tar with a content of 65-120 g / m3. The coke oven has been equipped with 120 heat exchangers of the rising pipe 1 to reduce the temperature of the raw coal gas from 750°C to 500°C, and the subsequent raw coal gas waste heat recovery equipment is used for cooling.

[0048] After the 500°C raw coal gas passes through the rising pipe 1, it enters the bridge pipe 17, and the first coal tar spray head 4 in the bridge pipe 17 sprays coal tar to reduce the temperature of the raw coal gas to below 280°C, and at the same time, the heavy tar in the raw coal gas is condensed. The raw coal gas and the coal tar enter the high-temperature gas collecting pipe 7, and the coal tar flows below the high-temperature gas collecting pipe 7, and the raw coal gas flows above the high-temperature gas collecting pipe 7.

[0049] The raw coal gas enters the first vertical pipe 5 upwardly through the high-temperature gas collecting pipe 7, and the second coal tar spray head 12 in the first vertical pipe 5 sprays coal tar, which countercurrently exchanges heat with the raw coal gas to reduce the temperature of the raw coal gas to 230°C. The coal tar sprayed in the bridge pipe 17 and the coal tar sprayed in the first vertical pipe 5 are combined together, flow through the pipe below the high-temperature gas collecting pipe 7, and flow into the heavy oil tank 8, which is pumped out by the high-temperature oil pump 9 and sent to the heat exchange boiler 22 to produce steam with a flow rate of 15 tons / hour. After the high-temperature coal tar is heat exchanged, the temperature is reduced to below 80°C, and the high-temperature coal tar enters the tar sedimentation tank 23 to separate tar residue, and then enters the tar storage tank.

[0050] The raw coal gas continues to enter the second vertical pipe 6, is sprayed with the first washing oil spray head 18, recovers light components, and enters the low-temperature gas collecting pipe 11 together. The temperature of the raw coal gas is reduced to 85°C, is separated through the gas-liquid separator 19, and enters the primary cooler 20. The raw coal gas is cooled to 25°C under the action of the circulating cooling water.

[0051] In addition, the second vertical pipe 6 adopts a pipe heat exchanger, and a plurality of heat exchange pipes are arranged inside. Water flows in the pipes to recover the heat of the raw coal gas and produce steam 3 tons / hour. The light oil adhered to the surfaces of the plurality of heat exchange pipes due to heat recovery is recovered by the spraying of the washing oil of the first washing oil spray head. The 85°C rich washing oil enters the rich oil storage tank 21, is sent to the rich oil heater 25 by the rich oil pump 24, is heated, and then enters the distillation tower 26 to distill naphthalene, phenol and light oil. The oil below the distillation tower 26 is lean oil, which is cooled by the heat exchanger and then returns to the π-shaped pipe to continue spraying and cooling.

[0052] The present example can recover the heat energy of the raw coal gas below 500°C, reduce the load of the subsequent primary cooler 20, and produce steam for use. The total steam production is 18 tons / hour, and the economic benefit per hour is 2700 yuan. Since the project is in production all year round, the annual economic benefit is 23,652,000 yuan of steam income.

[0053] Application Example Two: A coking enterprise with an annual output of 2,040,000 tons of coke. The raw coal gas quantity is 132,600 Nm³ / hour, and the tar content in the coal gas is 65-120 g / m³. At present, 144 up pipes 1 heat exchangers have been installed on the coke oven to reduce the temperature of the raw coal gas from 750°C to 500°C, and the subsequent raw coal gas waste heat recovery equipment is used for cooling.

[0054] After the 500°C raw coal gas passes through the up pipe 1, it enters the bridge pipe 17, the bridge pipe 17 sprays the coal tar to reduce the temperature of the raw coal gas to below 300°C, and the heavy tar in the raw coal gas is condensed. The raw coal gas and the tar enter the high-temperature gas collecting pipe 7, the coal tar flows below the high-temperature gas collecting pipe 7, and the raw coal gas flows above the high-temperature gas collecting pipe 7. The raw coal gas enters the first vertical pipe 5, sprays the coal tar, and the temperature of the raw coal gas is reduced to 230°C. The tar sprayed by the bridge pipe 17 and the tar sprayed by the first vertical pipe 5 are combined together, flow through the pipe below the high-temperature gas collecting pipe 7, and enter the heavy oil tank 8. The heavy oil pump 9 is used to send the heavy oil to the heat exchange boiler 22 to produce steam with a flow rate of 25 tons / hour. After the high-temperature tar is heat exchanged, the temperature is reduced to below 80°C, the tar residue is separated in the subsequent tar settling tank 23, and then the tar is stored in the tar storage tank.

[0055] The raw coal gas enters the second vertical pipe 6 of the π-shaped pipe, is sprayed with the first washing oil spray head 18, and the light components including naphthalene, phenol, light oil and other light components are recovered, and the temperature of the raw coal gas is reduced to 85°C, and enters the primary cooler 20. The second vertical pipe 6 is a tubular heat exchanger, and a plurality of heat exchange pipes are arranged in the tubular heat exchanger, water flows in the pipes, the heat of the raw coal gas is recovered, and 5 tons / hour of steam is produced. Due to the heat recovery, the light oil is attached to the surface of the pipe, and the spraying of the washing oil can recover the light tar on the surface of the pipe. The washing oil is also heat-exchanged with the raw coal gas, and after being heated, enters the rich oil storage tank 21, and then enters the subsequent chemical process to extract naphthalene, phenol, light oil and other light components. After the washing oil absorbs the naphthalene oil and the phenol oil by spraying the raw coal gas, the washing oil becomes rich washing oil, the rich washing oil is heated by the rich oil heater 25, and then enters the distillation tower 26, and after the naphthalene, phenol and other light components are recovered in stages, the washing oil becomes poor washing oil. After the poor washing oil is cooled, it enters the washing oil storage tank (not shown in the figure), and finally the poor washing oil is returned to the washing oil spray head in the second vertical pipe of the π-shaped pipe for continuous use.

[0056] The heat exchanger in the second vertical pipe 6 adopts a horizontal pipe heat exchange pipe, water flows in the pipe to cool the coal gas, and 3 tons / hour of saturated steam is produced, and the saturated steam pressure is 0.6 MPa.

[0057] The present example can recover the heat energy of the raw coal gas below 500°C, reduce the load of the subsequent primary cooler 20, and produce steam for use, a total of 30 tons / hour, 150 yuan per ton of steam, and an economic benefit of 4500 yuan per hour. Since the project is in production for 365 days, the direct economic income is 39.42 million yuan per year, and the steam income is 3942 million yuan per year.

[0058] As can be seen from the above examples, a raw coal gas waste heat recovery device after the riser pipe includes a bridge pipe 17 connected to the riser pipe 1, a high-temperature gas collecting pipe 7 connected to the outlet end of the bridge pipe 17, a π-shaped pipe connected to the top end gas outlet of the high-temperature gas collecting pipe 7, a low-temperature gas collecting pipe 11 connected to the outlet end of the π-shaped pipe, and a heavy oil tank 8, a high-temperature oil pump 9 and a heat exchange device 22 connected to the lower end of the high-temperature gas collecting pipe 7 in sequence; wherein the π-shaped pipe includes a first vertical pipe 5, a horizontal pipe 13 and a second vertical pipe 6 connected in sequence, the first vertical pipe 5 extends upward from the top end of the high-temperature gas collecting pipe 7, and a coal tar spray head 12 is arranged in the first vertical pipe 5, and the high-temperature oil pump 9 is used to deliver the coal tar sprayed from the coal tar spray head 12 to the heat exchange device 22 through the high-temperature gas collecting pipe 7 and the heavy oil tank 8 for waste heat recovery.

[0059] Further, a heat exchanger 61 is arranged in the second vertical pipe 6. The heat exchanger 61 can further cool the raw coal gas, recover the heat of the raw coal gas flowing through, and produce steam for output and utilization.

[0060] Further, the bottom end of the second vertical pipe 6 is connected with the top end of the low-temperature gas collecting pipe 11, and the subsequent coke oven gas waste heat recovery device of the rising pipe 1 further comprises a first washing oil spray head 18 arranged in the second vertical pipe 6, the heat exchanger 61 is arranged below the first washing oil spray head 18, and the first washing oil spray head 18 is arranged at the top of the second vertical pipe 6. Since the light oil contained in the coke oven gas will adhere to the surface of the heat exchange pipeline when the heat exchanger 61 exchanges heat with the coke oven gas, the washing oil sprayed by the first washing oil spray head 18 can carry away the light oil on the surface of the heat exchange pipeline, form rich washing oil, and enter the low-temperature gas collecting pipe 11 together.

[0061] Further, a plurality of second washing oil spray heads 16 are arranged at the top of the low-temperature gas collecting pipe 11, which can further spray and cool when the temperature of the coke oven gas is higher than 85℃; the low-temperature gas collecting pipe 11 is made of stainless steel, and the outer surface is heat-insulated by aluminum silicate fiber.

[0062] Further, the π-shaped pipe is a composite steel pipe, the inner surface is a non-stick coating layer, which prevents the accumulation of coal tar on the inner surface of the steel pipe; the outer part of the π-shaped pipe is a heat-insulating layer, which prevents heat loss caused by heat dissipation. The non-stick coating layer is a ceramic non-stick coating layer, and the outer heat-insulating layer is an aerogel heat-insulating layer.

[0063] Further, the bridge pipe 17 is a downwardly extending arc-shaped elbow pipe, the high-temperature gas collecting pipe 7 is arranged below the bridge pipe 17, and a coal tar spray head 4 for spraying coal tar is also arranged in the bridge pipe 17, so that the coal tar sprayed by the coal tar spray head can enter the high-temperature gas collecting pipe 7 downwardly, the coal tar spray head 4 is called the first coal tar spray head, and the coal tar spray head 12 in the first vertical pipe 5 is called the second coal tar spray head.

[0064] Further, the high-temperature valve 2 and the steam spray head 3 arranged in the bridge pipe 17 are further included, the high-temperature valve 2 is arranged close to the inlet end of the bridge pipe 17 to connect or disconnect the rising pipe 1 and the bridge pipe 17, so that when the rising pipe 1 is opened for burning in the later stage of the production of the carbonization chamber, the high-temperature valve 2 is closed to prevent air from entering the high-temperature gas collecting pipe 7 and also prevent the coke oven gas from being discharged from the high-temperature gas collecting pipe 7; when the coal is loaded, the high-temperature valve 2 is opened, and the coke oven gas enters the high-temperature gas collecting pipe 7 from the rising pipe 1. The steam spray head 3 is arranged between the high-temperature valve 2 and the first coal tar spray head 4. The steam spray head 3 is used for high-pressure blowing to form negative pressure when the coal is loaded, so as to suck the coke oven gas into the high-temperature gas collecting pipe 7.

[0065] Further, the high-temperature gas collecting pipe 7 adopts a double-layer steel pipe structure, the inner layer steel pipe of the high-temperature gas collecting pipe 7 is made of 304, 316, 309 or 310S material, which has the effects of high-temperature resistance and corrosion resistance; the outer layer steel pipe of the high-temperature gas collecting pipe 7 is made of carbon steel or stainless steel material.

[0066] Further, the inner layer steel pipe and the outer layer steel pipe of the double-layer steel pipe structure are supported by a steel structure, and an aluminum silicate ceramic fiber blanket is filled between the inner layer steel pipe and the outer layer steel pipe, so that the heat loss is greatly reduced.

[0067] Further, the inner layer structure of the heavy oil tank 8 is made of 304, 316, 309 or 310S material, which has the effects of high temperature resistance and corrosion resistance; and the outer layer structure of the heavy oil tank 8 is made of carbon steel or stainless steel material.

[0068] Further, the inner layer structure of the heavy oil tank 8 is made of 304, 316, 309 or 310S material, which has the effects of high temperature resistance and corrosion resistance; and the outer layer structure of the heavy oil tank 8 is made of carbon steel or stainless steel material.

[0069] Further, the heat exchange device 22 is a heat exchange boiler, the outlet of the high-temperature oil pump 9 is connected with the inlet of the heat exchange boiler through a high-temperature oil pipeline 10, so that the incoming coal tar is sent into the heat exchange boiler 22 for heat exchange to generate steam, and the steam is recycled. Of course, the heat exchange device 22 can also be a pipe heat exchanger 61 in the second vertical pipe 6 in the above-mentioned embodiment, which can also achieve the purpose of the present application.

[0070] Further, the gas-liquid separator 19, the primary cooler 20, the rich oil storage tank 21, the rich oil pump 24, the rich oil heater 25 and the distillation column 26 are further included; the inlet of the gas-liquid separator 19 is connected with the outlet of the low-temperature gas collecting pipe 11, the upper end outlet of the gas-liquid separator 19 is connected with the primary cooler 20, the bottom end outlet of the gas-liquid separator 19 is connected with the inlet of the rich oil storage tank 21, the outlet of the rich oil storage tank 21 is connected with the inlet of the rich oil pump 24, the outlet of the rich oil pump 24 is connected with the inlet of the bottom end of the rich oil heater 25, and the upper end outlet of the rich oil heater 25 is connected with the distillation column 26. On one hand, the raw coal gas separated by the gas-liquid separator 19 is cooled to 25 DEG C in the primary cooler 20 and then output; on the other hand, the rich washing oil entering the low-temperature gas collecting pipe 11 is separated by the gas-liquid separator 19 and then enters the rich oil storage tank 21, is sent to the rich oil heater 25 by the rich oil pump 24, is heated, and then enters the distillation column 26 to distill naphthalene, phenol and light oil.

[0071] Further, the gas-liquid separator 19, the primary cooler 20, the rich oil storage tank 21, the rich oil pump 24, the rich oil heater 25 and the distillation column 26 are further included; the inlet of the gas-liquid separator 19 is connected with the outlet of the low-temperature gas collecting pipe 11, the upper end outlet of the gas-liquid separator 19 is connected with the primary cooler 20, the bottom end outlet of the gas-liquid separator 19 is connected with the inlet of the rich oil storage tank 21, the outlet of the rich oil storage tank 21 is connected with the inlet of the rich oil pump 24, the outlet of the rich oil pump 24 is connected with the inlet of the bottom end of the rich oil heater 25, and the upper end outlet of the rich oil heater 25 is connected with the distillation column 26. On one hand, the raw coal gas separated by the gas-liquid separator 19 is cooled to 25 DEG C in the primary cooler 20 and then output; on the other hand, the rich washing oil entering the low-temperature gas collecting pipe 11 is separated by the gas-liquid separator 19 and then enters the rich oil storage tank 21, is sent to the rich oil heater 25 by the rich oil pump 24, is heated, and then enters the distillation column 26 to distill naphthalene, phenol and light oil.

[0072] To achieve the above-mentioned purpose, the present application further provides a waste heat recovery method using the subsequent raw coal gas waste heat recovery equipment of the above-mentioned rising pipe 1, which comprises the following steps: Coal tar is sprayed in the first vertical pipe 5 of the π-shaped pipe through a coal tar spraying head, so that the sprayed coal tar exchanges heat with the raw coal gas entering the first vertical pipe 5, and then enters the heat recovery device 22 through the high-temperature gas collecting pipe 7, the heavy oil tank 8 and the high-temperature oil pump 9 for heat recovery.

[0073] To achieve the above-mentioned purpose, the application further provides a waste heat recovery method using the subsequent raw coal gas waste heat recovery equipment of the riser 1, which comprises the following steps: Coal tar is sprayed in the first vertical pipe 5 of the π-shaped pipe through a coal tar spraying head, so that the sprayed coal tar exchanges heat with the raw coal gas entering the first vertical pipe 5, and then enters the heat recovery device 22 through the high-temperature gas collecting pipe 7, the heavy oil tank 8 and the high-temperature oil pump 9 for heat recovery; The raw coal gas after the first vertical pipe 5 continues to enter the second vertical pipe 6, exchanges heat with the heat exchanger 61 in the second vertical pipe 6, and then exchanges heat again through the heat exchanger 61.

[0074] The application has the following beneficial effects: First, the riser 1 of the coke oven can only reduce the raw coal gas to 500 DEG C, and the application can further recover the heat energy below 500 DEG C of the raw coal gas, reduce the load of the primary cooler, produce steam for use, and improve economic benefits.

[0075] Second, the coal tar and the raw coal gas directly exchange heat through the coal tar spraying head in the first vertical pipe 5, the heat exchange efficiency is high, and the coal tar steam in the raw coal gas is washed by the coal tar and enters the high-temperature gas collecting pipe 7; the coal tar washing washes the coal tar separated out of the raw coal gas and flows downward into the high-temperature gas collecting pipe 7, and the process solves the problem of pipe blockage caused by the separation of coal tar below 500 DEG C.

[0076] Third, the coal tar spraying head sprays coal tar in the first vertical pipe 5, and no ammonia water is sprayed, so that the water content of the coal tar is greatly reduced and the quality of the coal tar is improved. In the previous process, spraying ammonia water causes the water content of the coal tar to be 4%, and in the subsequent distillation of the coal tar to extract various components, dehydration is required before distillation. Since the water content of the coal tar is low in the process, the energy consumption of the subsequent production can be reduced.

[0077] Fourth, in the traditional bridge pipe 17 ammonia water spraying process, the accumulated ammonium salt in the circulating ammonia water causes the salt content of the coal tar to increase, and sodium carbonate needs to be added in the subsequent production to separate ammonia, and the salt finally exists in the coal tar in the form of sodium chloride. In the application, the ammonia water spraying device is cancelled, the salt content of the coal tar is low, the quality of the coal tar is further improved, the selling price of the recovered coal tar is improved, and the economic benefits are improved.

Claims

1. A riser-type waste gas waste heat recovery device, characterized by: It includes a bridge pipe connected to a riser, a high-temperature gas collecting pipe connected to the outlet end of the bridge pipe, a π-shaped pipe connected to the gas outlet at the top of the high-temperature gas collecting pipe, a low-temperature gas collecting pipe connected to the outlet end of the π-shaped pipe, a heavy oil tank connected to the lower end of the high-temperature gas collecting pipe in sequence, a high-temperature oil pump and a heat exchange device; wherein, the π-shaped pipe includes a first vertical pipe, a horizontal pipe and a second vertical pipe connected in sequence, the first vertical pipe extends upward from the top of the high-temperature gas collecting pipe, and a coal tar spray head is provided in the first vertical pipe, and the high-temperature oil pump is used to transport the coal tar sprayed from the coal tar spray head through the high-temperature gas collecting pipe and the heavy oil tank to the heat exchange device for waste heat recovery.

2. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: Also included is a heat exchanger disposed in the second vertical pipe.

3. The riser subsequent raw gas waste heat recovery equipment according to claim 2, characterized in that: The bottom end of the second vertical pipe is connected to the top of the low-temperature gas collecting pipe. The subsequent raw gas waste heat recovery equipment of the riser also includes a first oil washing spray head arranged in the second vertical pipe. The heat exchanger is located below the first oil washing spray head, and the first oil washing spray head is arranged at the top of the second vertical pipe.

4. The riser subsequent raw gas waste heat recovery equipment according to claim 3, characterized in that: A plurality of second oil washing spray heads are provided on the top of the low-temperature gas collecting pipe. The low-temperature gas collecting pipe is made of stainless steel and its surface is insulated with aluminum silicate fiber.

5. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: The π-shaped tube is a composite steel tube, the inner surface of which is a non-stick coating, the outside of which is a thermal insulation layer, the non-stick coating is a ceramic non-stick coating, and the outer thermal insulation layer is an aerogel thermal insulation layer.

6. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: The bridge pipe is an arc-shaped curved pipe extending downward, and the high-temperature gas collecting pipe is arranged below the bridge pipe. A coal tar spray head for coal tar spraying is also provided in the bridge pipe, so that the coal tar sprayed by the coal tar spray head can enter the high-temperature gas collecting pipe downward. The coal tar spray head is called the first coal tar spray head, and the coal tar spray head in the first vertical pipe is called the second coal tar spray head.

7. The riser subsequent raw gas waste heat recovery equipment according to claim 6, characterized in that: It also includes a high-temperature valve and a steam nozzle arranged in the bridge pipe. The high-temperature valve is arranged near the inlet end of the bridge pipe to connect or disconnect the riser and the bridge pipe. The steam nozzle is arranged between the high-temperature valve and the first coal tar nozzle.

8. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: The high-temperature gas collecting pipe adopts a double-layer steel pipe structure. The inner steel pipe of the high-temperature gas collecting pipe is made of 304, 316, 309 or 310S material, and the outer steel pipe of the high-temperature gas collecting pipe is made of carbon steel or stainless steel.

9. The riser subsequent raw gas waste heat recovery equipment according to claim 8, characterized in that: The inner steel pipe and the outer steel pipe of the double-layer steel pipe structure are supported by a steel structure, and an aluminum silicate ceramic fiber blanket is filled between the inner steel pipe and the outer steel pipe.

10. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: The heavy oil tank adopts a double-layer structure, the inner layer structure material of the heavy oil tank is 304, 316, 309 or 310S material, and the outer layer structure of the heavy oil tank is carbon steel or stainless steel.

11. The riser subsequent raw gas waste heat recovery equipment according to claim 10, characterized in that: The inner layer structure and the outer layer structure of the heavy oil tank are supported by a steel structure, and the space between the inner layer structure and the outer layer structure is filled with a heat-insulating material, which is an aluminum silicate ceramic fiber blanket.

12. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: The heat exchange device is a heat exchange boiler, and the outlet of the high-temperature oil pump is connected to the inlet of the heat exchange boiler through a high-temperature oil pipeline.

13. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: It also includes a gas-liquid separator, a primary cooler, an oil-rich storage tank, an oil-rich pump, an oil-rich heater and a distillation tower; the inlet of the gas-liquid separator is connected to the outlet of the low-temperature gas collecting pipe, and the upper outlet of the gas-liquid separator is upwardly connected to the primary cooler; the bottom outlet of the gas-liquid separator is connected to the inlet of the oil-rich storage tank, the outlet of the oil-rich storage tank is connected to the inlet of the oil-rich pump, the outlet of the oil-rich pump is connected to the inlet of the bottom end of the oil-rich heater, and the outlet of the oil-rich heater is connected to the distillation tower.

14. The riser subsequent raw gas waste heat recovery equipment according to claim 1, characterized in that: It also includes a tar precipitation tank connected to the bottom outlet of the heat exchange boiler and a tar storage tank connected to the tar precipitation tank.

15. A waste heat recovery method using a riser subsequent raw gas waste heat recovery device according to any one of claims 1 to 14, characterized in that: The following steps are involved: Coal tar is sprayed in the first vertical pipe of the π-shaped pipe through a coal tar spray head, so that the sprayed coal tar exchanges heat with the raw coal gas entering the π-shaped pipe, and then enters the heat exchange device for heat recovery after passing through the high-temperature gas collecting pipe, heavy oil tank, and high-temperature oil pump.

16. A waste heat recovery method using a riser-pipe subsequent raw gas waste heat recovery device as claimed in any one of claims 2 to 4, characterized in that: The following steps are involved: Coal tar is sprayed in the first vertical pipe of the π-shaped pipe through a coal tar spray head, so that the sprayed coal tar exchanges heat with the raw coal gas entering the first vertical pipe, and then enters the heat exchange device for heat recovery after passing through the high-temperature gas collecting pipe, heavy oil tank, and high-temperature oil pump; The raw gas after passing through the first vertical pipe continues to enter the second vertical pipe, exchanges heat with the heat exchanger in the second vertical pipe, and then recovers heat again through the heat exchanger.

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