A kind of inner and outer double-jacketed tube riser heat exchanger

Abstract

The present invention relates to an inner and outer double-jacketed tubular riser heat exchanger, which has a body and a heat exchange tube; the body includes an outer layer cylinder and an inner layer cylinder; the heat exchange tube includes an outer layer heat exchange tube and an inner layer heat exchange tube; the inner layer cylinder is fixedly arranged in the outer layer cylinder; the outer layer cylinder and the inner layer cylinder are respectively provided with an outer interlayer and an inner interlayer; the outer layer heat exchange tube and the inner layer heat exchange tube are respectively arranged in the outer interlayer and the inner interlayer; the outer interlayer and the inner interlayer are both provided with heat conductive materials; a first channel for raw coal gas to pass through is formed between the inner layer cylinder and the outer layer cylinder, and a second channel for raw coal gas to pass through is formed inside the inner layer cylinder. The present invention can overcome the shortcomings of the prior art, greatly increase the heat exchange area, increase the temperature rise of the heat exchange medium, obtain a high-grade heat source, reduce the amount of cooling ammonia water, improve the waste heat utilization efficiency of raw coal gas, prevent coking and corrosion of the riser heat exchanger, and at the same time avoid leakage of the heat exchange medium into the carbonization chamber.

Description

Technical Field

[0001] This invention relates to heat exchange equipment, and particularly to a double-jacketed riser heat exchanger. Background Technology

[0002] my country is a major producer of coke, possessing various types of coking ovens and producing a huge amount of coke. Besides heat dissipation from the oven surface, the waste heat from coke ovens mainly consists of the following three parts: (1) high-temperature waste heat carried out from the 950℃~1050℃ red coke pushed out of the coke oven carbonization chamber, accounting for approximately 37.52% of the total heat output from the coke oven; (2) medium-temperature waste heat carried out from the 650~800℃ raw coal gas, accounting for approximately 33.76% of the total heat output from the coke oven; and (3) low-temperature waste heat carried out from the 260℃ coke oven flue gas, accounting for approximately 18.15% of the total heat output from the coke oven. Currently, there are mature technologies for recovering waste heat from red-hot coke and flue gas. However, for the waste heat of raw coal gas at 650-800℃, the commonly used process is as follows: first, circulating ammonia water is sprayed into the bridge pipe and gas collecting pipe to directly contact the raw coal gas. The large-scale vaporization of the circulating ammonia water rapidly cools the raw coal gas to 80-85℃. The cooled raw coal gas is then indirectly cooled to 25℃ in a primary cooler using cooling water. The ammonia water is then cooled and detarted before being recycled. In this process, a large amount of heat energy contained in the raw coal gas is carried away by the cooling ammonia water. The cooled ammonia water is then discharged after evaporation and ammonia removal. This process consumes a large amount of ammonia water, increasing production costs, while the waste heat resources of the raw coal gas cannot be recovered and are lost. Therefore, the recovery of the sensible heat carried away by the raw coal gas plays a very important role in energy conservation, emission reduction, and improving economic efficiency in coking plants.

[0003] The technology of waste heat recovery from raw coke oven gas has been studied since the 1980s, but due to the thermal properties of raw coke oven gas and the safety issues of coke oven production, the waste heat recovery of raw coke oven gas has not progressed smoothly. In summary, there are the following key technical points or difficulties: (1) When the temperature of raw coke oven gas is lower than a certain value, graphite deposition and tar precipitation are easy, and the adhesion and coking are serious, resulting in the reduction of the inner wall space and the decrease of the heat transfer coefficient; (2) Pressure resistance operation, the temperature rise of the heat transfer medium is not high; (3) During the waste heat recovery process, the heat exchange medium is prone to leakage, which affects the safety of the carbonization chamber.

[0004] Some existing raw coal gas riser heat exchangers mainly use water, heat transfer oil, nitrogen, or other heat transfer media in their jacketed or coiled structures. However, these technologies are characterized by high operating pressure of the heat transfer medium, small temperature rise after heat absorption, and ultimately low pressure and temperature of the steam produced by the system, making it a low-grade heat source with low utilization value. Furthermore, the heat transfer medium is prone to leakage into the coking chamber, affecting the normal operation of the coke oven. Summary of the Invention

[0005] The purpose of this invention is to provide an internal and external double-jacketed tube-type riser heat exchanger, which can overcome the shortcomings of the prior art, greatly increase the heat exchange area, improve the temperature rise of the heat exchange medium, obtain a high-grade heat source, reduce the amount of cooling ammonia water used, improve the waste heat utilization efficiency of raw coal gas, prevent coking and corrosion of the riser heat exchanger, and at the same time prevent the heat exchange medium from leaking into the carbonization chamber.

[0006] The technical solution to achieve the objective of this invention is as follows: This invention comprises a body and a heat exchange tube; the body includes an outer cylinder and an inner cylinder; the heat exchange tube includes an outer heat exchange tube and an inner heat exchange tube; the inner cylinder is fixedly disposed within the outer cylinder; the outer cylinder and the inner cylinder are respectively provided with an outer jacket and an inner jacket; the outer heat exchange tube and the inner heat exchange tube are respectively disposed within the outer jacket and the inner jacket; both the outer jacket and the inner jacket are provided with heat-conducting material; a space is formed between the inner cylinder and the outer cylinder for the passage of raw coal gas. The first channel is formed inside the inner cylinder for the passage of raw coal gas; the heat exchange medium inlets of the outer heat exchange tube and the inner heat exchange tube are connected to form the total heat exchange medium inlet, and the heat exchange medium outlets of the outer heat exchange tube and the inner heat exchange tube are connected to form the total heat exchange medium outlet; or the heat exchange medium outlet of the outer heat exchange tube is connected to the heat exchange medium inlet of the inner heat exchange tube, and the heat exchange medium inlet of the outer heat exchange tube is the total heat exchange medium inlet, and the heat exchange medium outlet of the inner heat exchange tube is the total heat exchange medium outlet.

[0007] The outer heat exchange tube is a first spiral coil with the axis of the outer cylinder as the spiral axis; the inner heat exchange tube is a second spiral coil with the axis of the inner cylinder as the spiral axis.

[0008] The heat exchange medium inlet of the first spiral coil is located at the lower end of the outer shell, and the heat exchange medium outlet of the first spiral coil is located at the upper end of the outer shell and is connected to the heat exchange medium inlet of the second spiral coil; the heat exchange medium inlet of the second spiral coil is located at the upper end of the inner shell, and the heat exchange medium outlet of the second spiral coil is located at the lower end of the inner shell.

[0009] The aforementioned outer cylinder includes an outer cylinder and an inner cylinder; the outer cylinder and the inner cylinder are fixedly connected and form an outer interlayer between them; the outer cylinder is provided with an expansion joint.

[0010] The aforementioned thermally conductive materials are one or more of silicon carbide, aluminum nitride, zinc oxide, boron nitride, toner, graphene, carbon powder, calcium titanium powder, silica powder, metal powder, and thermally conductive solid powders, or a mixture thereof.

[0011] The upper and lower ends of the outer cylinder are respectively fixed with an upper flange and a lower flange.

[0012] The aforementioned upper and lower flanges are made of metal or ceramic.

[0013] The inner wall of the outer cylinder and the outer wall of the inner cylinder are both coated with a thermally conductive coating. The thermally conductive coating can be a high-temperature resistant far-infrared radiation coating (ZS-1061) developed and produced by Beijing Zhisheng Weihua Chemical Co., Ltd. This high-temperature resistant far-infrared radiation coating has a self-cleaning effect, effectively preventing coking on the inner wall of the outer cylinder and the outer wall of the inner cylinder.

[0014] The aforementioned inner cylinder is fixedly installed inside the outer cylinder by a support and limiting device; the support and limiting device includes a lower support limiting component and an upper limiting component;

[0015] The lower support and limiting assembly includes a support plate, and a first limiting plate and a second limiting plate fixedly connected to the support plate; the support plate is fixedly connected to the inner wall of the outer cylinder and located at the lower end of the inner cylinder; a first limiting groove is formed between the first limiting plate and the second limiting plate; the inner cylinder is supported by the support plate and limited by the first limiting groove after its lower end is inserted into the first limiting groove; multiple lower support and limiting assemblies are distributed circumferentially around the axis of the inner cylinder at the lower end of the inner cylinder;

[0016] The upper limit assembly includes a connecting plate, and a third limiting plate and a fourth limiting plate fixedly connected to the connecting plate; the connecting plate is fixedly connected to the inner wall of the outer cylinder and located at the upper end of the inner cylinder; a second limiting groove is formed between the third limiting plate and the fourth limiting plate; the inner cylinder is limited by the second limiting groove after being inserted into it at its upper end; multiple upper limit assemblies are distributed circumferentially around the axis of the inner cylinder at the upper end of the inner cylinder.

[0017] Molten salt is preferred as the heat exchange medium in the heat exchange tubes, but heat transfer oil, water, gas, and other heat exchange media can also be selected.

[0018] The present invention has positive effects: (1) The present invention uses an outer cylinder and an inner cylinder to form a first channel and a second channel. Because it has a first channel and a second channel (i.e., a double channel), the heat exchange area is greatly increased, thereby greatly improving the heat exchange efficiency. At the same time, since the inner heat exchange tube is located in the inner jacket, it can effectively prevent the heat exchange medium from leaking into the carbonization chamber.

[0019] (2) Because of its large heat absorption capacity, the present invention can reduce the amount of cooling ammonia water used, and at the same time avoid coking and corrosion.

[0020] (3) This invention provides elastic compensation for the additional stress caused by temperature difference and mechanical vibration through expansion energy saving.

[0021] (4) The present invention utilizes a support limiting device to support and fix the inner cylinder, effectively preventing the inner jacket layer from shaking. Attached Figure Description

[0022] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0025] Figure 3 for Figure 1 Enlarged view of point B in the middle;

[0026] Figure 4 This is a top view of the outer and inner cylinders in this invention. Detailed Implementation

[0027] See Figures 1 to 4 The present invention comprises a body and a heat exchange tube 1; the body includes an outer cylinder 2 and an inner cylinder 3; the heat exchange tube 1 includes an outer heat exchange tube 11 and an inner heat exchange tube 12; the inner cylinder 3 is fixedly disposed inside the outer cylinder 2; the outer cylinder 2 and the inner cylinder 3 are respectively provided with an outer interlayer and an inner interlayer; the outer heat exchange tube 11 and the inner heat exchange tube 12 are respectively disposed in the outer interlayer and the inner interlayer; both the outer interlayer and the inner interlayer are provided with a heat-conducting material 4; a first channel 5 for the passage of raw coal gas is formed between the inner cylinder 3 and the outer cylinder 2, and a second channel 6 for the passage of raw coal gas is formed inside the inner cylinder 2.

[0028] The outer heat exchange tube 11 is a first spiral coil with the axis of the outer cylinder 2 as the spiral axis; the inner heat exchange tube 12 is a second spiral coil with the axis of the inner cylinder 3 as the spiral axis.

[0029] The heat exchange medium inlet of the first spiral coil is located at the lower end of the outer cylinder 2, and the heat exchange medium outlet of the first spiral coil is located at the upper end of the outer cylinder 2 and is connected to the heat exchange medium inlet of the second spiral coil; the heat exchange medium inlet of the second spiral coil is located at the upper end of the inner cylinder 3, and the heat exchange medium outlet of the second spiral coil is located at the lower end of the inner cylinder 3; the heat exchange medium inlet of the first spiral coil is the total heat exchange medium inlet 13, and the heat exchange medium outlet of the second spiral coil is the total heat exchange medium outlet 14.

[0030] The outer cylinder 2 includes an outer cylinder 21 and an inner cylinder 22; the outer cylinder 21 and the inner cylinder 22 are fixedly connected and form an outer interlayer between them; the outer cylinder 21 is provided with an expansion joint 23.

[0031] The thermally conductive material 4 is one or more of silicon carbide, aluminum nitride, zinc oxide, boron nitride, toner, graphene, carbon powder, calcium titanium powder, silica powder, metal powder, and thermally conductive solid powder, or a mixture thereof.

[0032] The upper flange 7 and the lower flange 8 are fixedly installed at the upper and lower ends of the outer cylinder 2, respectively.

[0033] The upper flange 7 is a metal part, and the lower flange 8 is a ceramic part.

[0034] The inner wall of the outer cylinder 2 and the outer wall of the inner cylinder 3 are both coated with a thermally conductive coating. The thermally conductive coating is a high-temperature resistant far-infrared radiation coating (ZS-1061) developed and produced by Beijing Zhisheng Weihua Chemical Co., Ltd. This high-temperature resistant far-infrared radiation coating has a self-cleaning effect, effectively preventing coking on the inner wall of the outer cylinder 2 and the outer wall of the inner cylinder 3.

[0035] The inner cylinder 3 is fixedly installed inside the outer cylinder 2 by a support and limiting device 9; the support and limiting device 9 includes a lower support and limiting component 91 and an upper limit component 92.

[0036] The lower support and limiting assembly 91 includes a support plate 911, and a first limiting plate 912 and a second limiting plate 913 fixedly connected to the support plate 911; the support plate 911 is fixedly connected to the inner wall of the outer cylinder 2 and located at the lower end of the inner cylinder 3; a first limiting groove is formed between the first limiting plate 912 and the second limiting plate 913; the inner cylinder 3 is supported by the support plate 911 and limited by the first limiting groove after its lower end is inserted into the first limiting groove; a plurality of lower support and limiting assemblies 91 are distributed circumferentially around the axis of the inner cylinder 3 at the lower end of the inner cylinder 3.

[0037] The upper limit assembly 92 includes a connecting plate 921, and a third limiting plate 922 and a fourth limiting plate 923 fixedly connected to the connecting plate 921; the connecting plate 921 is fixedly connected to the inner wall of the outer cylinder 2 and located at the upper end of the inner cylinder 3; a second limiting groove is formed between the third limiting plate 922 and the fourth limiting plate 923; the inner cylinder 3 is limited by the second limiting groove after its upper end is inserted into it; multiple upper limit assemblies 92 are distributed circumferentially around the axis of the inner cylinder 3 at the upper end of the inner cylinder 3.

[0038] The support plate 911 and the connecting plate 921 are offset from each other in the axial projection direction of the inner cylinder 3. This allows the raw coal gas to stay briefly in the first channel 5, which further improves the heat exchange efficiency to a certain extent.

[0039] Molten salt is preferred as the heat exchange medium in heat exchange tube 1. When recovering the waste heat of raw coal gas using molten salt, the heat exchanger's lifespan can be increased because the molten salt operates at atmospheric pressure. At the same time, because the molten salt temperature rises (580℃), the heat exchange between the molten salt and water in the later stage can generate high-temperature and high-pressure steam, which is a high-quality heat source.

[0040] The working principle of this invention is as follows:

[0041] The heat exchange medium enters from the total inlet 13 and exits from the total outlet 14. During the flow of the heat exchange medium, it can absorb the heat from the raw coal gas passing through the first channel 5 and the second channel 6. Since both the outer and inner walls of the inner cylinder 3 are in contact with the raw coal gas, its heat absorption efficiency is extremely high.

[0042] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An inner and outer double-jacketed tubular riser heat exchanger, comprising a body and a heat exchange tube; characterized in that: The body comprises an outer layer cylinder and an inner layer cylinder; the heat exchange tube comprises an outer layer heat exchange tube and an inner layer heat exchange tube; the inner layer cylinder is fixedly arranged in the outer layer cylinder; the outer layer cylinder and the inner layer cylinder are respectively provided with an outer interlayer and an inner interlayer; the outer layer heat exchange tube and the inner layer heat exchange tube are respectively arranged in the outer interlayer and the inner interlayer; the outer interlayer and the inner interlayer are both provided with heat conducting materials; a first channel for raw gas to pass through is formed between the inner layer cylinder and the outer layer cylinder, and the inner layer of the inner layer cylinder is provided with a heat conducting material; ... The heat exchange medium inlets of the outer heat exchange tubes and the inner heat exchange tubes are connected to form a total heat exchange medium inlet, and the heat exchange medium outlets of the outer heat exchange tubes and the inner heat exchange tubes are connected to form a total heat exchange medium outlet; or the heat exchange medium outlet of the outer heat exchange tubes is connected to the heat exchange medium inlet of the inner heat exchange tubes, the heat exchange medium inlet of the outer heat exchange tubes is the total heat exchange medium inlet, and the heat exchange medium outlet of the inner heat exchange tubes is the total heat exchange medium outlet.

2. The inner and outer double-jacketed tubular riser heat exchanger according to claim 1, characterized in that: The outer heat exchange tube is a first spiral coil with the axis of the outer cylinder as the spiral axis; the inner heat exchange tube is a second spiral coil with the axis of the inner cylinder as the spiral axis.

3. The inner and outer double-jacketed tubular riser heat exchanger according to claim 2, characterized in that: The heat exchange medium inlet of the first spiral coil is located at the lower end of the outer cylinder, and the heat exchange medium outlet of the first spiral coil is located at the upper end of the outer cylinder and is connected to the heat exchange medium inlet of the second spiral coil; the heat exchange medium inlet of the second spiral coil is located at the upper end of the inner cylinder, and the heat exchange medium outlet of the second spiral coil is located at the lower end of the inner cylinder.

4. The inner and outer double-jacketed tubular riser heat exchanger according to claim 1, 2 or 3, characterized in that: The outer cylinder comprises an outer cylinder and an inner cylinder; the outer cylinder and the inner cylinder are fixedly connected and an outer interlayer is formed therebetween; an expansion joint is arranged on the outer cylinder.

5. The inner and outer double-jacketed tubular riser heat exchanger according to claim 1, 2 or 3, characterized in that: The thermally conductive material is a mixture of one or more of silicon carbide, aluminum nitride, zinc oxide, boron nitride, toner, graphene, carbon powder, perovskite powder, silica powder, metal powder, and thermally conductive solid powder.

6. The inner and outer double-jacketed tubular riser heat exchanger according to claim 1, characterized in that: An upper flange and a lower flange are fixedly provided at the upper end and the lower end of the outer cylinder respectively.

7. The inner and outer double-jacketed tubular riser heat exchanger according to claim 6, characterized in that: The upper flange and the lower flange are metal parts or ceramic parts.

8. The inner and outer double-jacketed tubular riser heat exchanger according to claim 1, characterized in that: The inner wall of the outer cylinder and the outer wall of the inner cylinder are both coated with a thermal conductive coating.

9. The inner and outer double-jacketed tubular riser heat exchanger according to claim 1, 2 or 3, characterized in that: The inner cylinder is fixedly arranged in the outer cylinder through a support and limit device; the support and limit device comprises a lower support and limit assembly and an upper limit assembly; The lower support and limit assembly comprises a support plate, and a first limit plate and a second limit plate fixedly connected to the support plate; the support plate is fixedly connected to the inner wall of the outer cylinder and is located at the lower end of the inner cylinder; a first limit slot is formed between the first limit plate and the second limit plate; the inner cylinder is supported by the support plate and limited by the first limit slot after its lower end is inserted into the first limit slot; a plurality of lower support and limit assemblies are distributed circumferentially around the axis of the inner cylinder at the lower end of the inner cylinder; The upper limit assembly includes a connecting plate, and a third limit plate and a fourth limit plate fixedly connected to the connecting plate; the connecting plate is fixedly connected to the inner wall of the outer cylinder and is located at the upper end of the inner cylinder; a second limit slot is formed between the third limit plate and the fourth limit plate; the inner cylinder is limited by the second limit slot after its upper end is inserted into the second limit slot; the upper end of the inner cylinder is provided with a plurality of upper limit assemblies distributed circumferentially around the axis of the inner cylinder.

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