Coke oven riser raw gas waste heat recovery device and method

Abstract

The invention relates to a coke oven riser raw gas waste heat recovery device and method.The coke oven riser raw gas waste heat recovery device comprises a combined heat exchanger, a steam pocket and a forced circulation pump, and the combined heat exchanger comprises an inner cylinder, an outer cylinder, a first heat exchange pipeline and a second heat exchange pipeline; the inner cylinder is connected between the ascending pipe tee joint and the ascending pipe base, the outer cylinder is arranged outside the inner cylinder in a sleeving mode, a gap is formed between the outer cylinder and the inner cylinder and comprises a first heat exchange section and a second heat exchange section in the flowing direction of raw gas, the first heat exchange pipeline is arranged in the first heat exchange section, and the second heat exchange pipeline is arranged in the second heat exchange section; a saturated steam outlet of the steam pocket is communicated with the first heat exchange pipeline; a water outlet of the steam pocket, the forced circulation pump, the second heat exchange pipeline and a water inlet of the steam pocket are connected in series. The waste heat recovery device can fully recover heat in raw coke oven gas, the temperature of output steam is increased, and superheated steam is formed, so that generation of condensed water in the conveying process is reduced, and the use requirements of various users are met.

Description

Technical Field

[0001] The invention relates to the technical field of coke oven waste heat utilization, and in particular to a coke oven riser raw gas waste heat recovery device and method. Background Art

[0002] Coke oven raw gas is formed by the escape of volatile components of coking coal during the coking process. The gas temperature is about 600-800℃, and its sensible heat accounts for about 33% of the coke oven expenditure. For this reason, various riser waste heat utilization technologies have been developed in China to absorb the heat in the raw gas to directly generate steam for heating. At present, the pressure of steam generated by the riser waste heat technology is between 0.6-2MPa, which is saturated steam, and the temperature of saturated steam is between 160℃-210℃. During the transportation process, saturated steam will produce a large amount of condensed water when it encounters cold, and at the same time, the steam temperature is not high, so the use scenarios are limited. Summary of the invention

[0003] The first object of the present invention is to provide a coke oven riser raw gas waste heat recovery device so that it can effectively recover and utilize the waste heat of the coke oven raw gas, increase the steam temperature generated by it, and reduce the generation of condensed water.

[0004] The second object of the present invention is to provide a waste heat recovery method based on the above-mentioned coke oven riser raw gas waste heat recovery device.

[0005] To achieve the above object, the present invention provides the following technical solutions: A coke oven riser raw gas waste heat recovery device, comprising a combined heat exchanger, a steam drum and a forced circulation pump; The combined heat exchanger comprises an inner tube, an outer tube, a first heat exchange pipeline and a second heat exchange pipeline. The inner tube is connected between the riser tee and the riser base to form a raw gas supply channel between the riser tee and the riser base. The outer tube is sleeved outside the inner tube. There is a gap between the outer tube and the inner tube. Along the flow direction of the raw gas, the gap includes a first heat exchange section and a second heat exchange section. The first heat exchange pipeline is arranged in the first heat exchange section, and the second heat exchange pipeline is arranged in the second heat exchange section. The saturated steam outlet of the steam drum is in communication with the first heat exchange pipeline; The water outlet of the drum, the forced circulation pump, the second heat exchange pipeline and the water supply port of the drum are connected in series to form a water circulation loop.

[0006] In one embodiment of the present application, an expansion gap is provided between one of the riser tee and the riser base and the outer tube, and the other of the riser tee and the riser base is connected to the end of the outer tube.

[0007] In one embodiment of the present application, the expansion gap is 5 mm to 10 mm.

[0008] In one embodiment of the present application, the inner cylinder is a stainless steel cylinder, and the outer cylinder is a carbon steel cylinder.

[0009] In one embodiment of the present application, it also includes a water supply system, which includes a desalted water tank, a deoxygenated water feed pump, a deaerator and a boiler feed pump, and the desalted water tank, the deoxygenated water feed pump, the deaerator, the boiler feed pump and the water feed port of the steam drum are connected in series in sequence.

[0010] In one embodiment of the present application, it also includes a control system, which includes a controller, a liquid level detection device, a saturated water temperature detection device, a saturated water pressure detection device, a steam temperature detection device and a steam pressure detection device. The liquid level detection device is used to detect the liquid level in the steam drum, the saturated water temperature detection device is used to detect the outlet saturated water temperature of the second heat exchange pipeline, the saturated water pressure detection device is used to detect the outlet saturated water pressure of the second heat exchange pipeline, the steam temperature detection device is used to detect the outlet steam temperature of the first heat exchange pipeline, and the steam pressure detection device is used to detect the outlet steam pressure of the first heat exchange pipeline. The controller is respectively communicated with the liquid level detection device, the saturated water temperature detection device, the saturated water pressure detection device, the steam temperature detection device, the steam pressure detection device, the steam drum, the boiler feed water pump and the forced circulation pump.

[0011] In one embodiment of the present application, the first heat exchange pipeline is spirally coiled around the first heat exchange section, and the two ends of the first heat exchange pipeline are respectively a saturated steam inlet and a superheated steam outlet. Along the flow direction of the raw gas, the saturated steam inlet is located upstream of the superheated steam outlet, and the saturated steam inlet is connected to the saturated steam outlet of the steam drum, and the superheated steam outlet is used to connect to user equipment.

[0012] In one embodiment of the present application, the second heat exchange pipeline is spirally coiled around the second heat exchange section, and the two ends of the second heat exchange pipeline are respectively a saturated water inlet and a saturated water outlet. Along the flow direction of the raw gas, the saturated water inlet is located upstream of the saturated water outlet, the saturated water inlet is connected to the forced circulation pump, and the saturated water outlet is connected to the water supply port of the steam drum.

[0013] A waste heat recovery method based on the coke oven riser raw gas waste heat recovery device described in any one of the above, comprising the steps of: The liquid water in the drum is transported to the second heat exchange pipeline of the combined heat exchanger of each riser of the coke oven through a forced circulation pump, and the liquid water exchanges heat with the raw coal gas passing through the combined heat exchanger in the second heat exchange pipeline to form liquid-gas saturated water of a first preset pressure and a first preset temperature, and the liquid-gas saturated water returns to the drum for vapor-liquid separation, and the separated liquid water is then transported to the second heat exchange pipeline of the combined heat exchanger of each riser of the coke oven through a forced circulation pump, and circulates continuously; The gaseous steam in the steam drum is transported to the first heat exchange pipeline of the combined heat exchanger of each riser of the coke oven under the action of the pressure in the steam drum. The gaseous steam exchanges heat with the raw coal gas passing through the combined heat exchanger in the first heat exchange pipeline to form superheated steam of a second preset pressure and a second preset temperature. The superheated steam in the combined heat exchangers of each riser of the coke oven is combined and transported to the user equipment.

[0014] In one embodiment of the present application, the steps are further included: The liquid level in the drum is detected. If the liquid level in the drum drops to a preset level, the desalted water in the desalted water tank is transported to the deaerator for deoxygenation through the deaerator feed water pump, and the desalted water after deoxygenation is transported to the drum through the boiler feed water pump.

[0015] It can be seen from the above technical scheme that the present invention discloses a coke oven riser raw gas waste heat recovery device, which comprises a combined heat exchanger, a steam drum and a forced circulation pump, wherein the combined heat exchanger comprises an inner tube, an outer tube, a first heat exchange pipeline and a second heat exchange pipeline, the inner tube is connected between the riser tee and the riser base to form a raw gas supply channel between the riser tee and the riser base, the outer tube is sleeved outside the inner tube, and there is a gap between the outer tube and the inner tube, along the flow direction of the raw gas, the gap comprises a first heat exchange section and a second heat exchange section, the first heat exchange pipeline is arranged in the first heat exchange section, and the second heat exchange pipeline is arranged in the second heat exchange section; the saturated steam outlet of the steam drum is connected to the first heat exchange pipeline; the water outlet of the steam drum, the forced circulation pump, the second heat exchange pipeline and the water supply port of the steam drum are connected in series to form a water circulation loop.

[0016] When used, the liquid water in the drum is transported to the second heat exchange pipeline by the forced circulation pump, and the liquid water exchanges heat with the raw coal gas in the second heat exchange pipeline to be heated to 2.0MPa, 180℃~210℃ liquid-gas saturated water, and then sent back to the drum, the liquid-gas saturated water is separated into vapor and liquid in the drum, and the separated liquid water is transported to the second heat exchange pipeline in the combined heat exchanger of each riser of the coke oven by the forced circulation pump, and circulates continuously. The gaseous steam separated in the drum is pressed into the first heat exchange pipeline of the combined heat exchanger in the riser of each coke oven under the action of the drum pressure. After the gaseous steam exchanges heat with the raw coal gas in the first heat exchange pipeline, the saturated steam of 2.0MPa and 180℃~210℃ is changed into superheated steam of 2.0MPa and 300℃~350℃. The generated superheated steam is combined and directly transported to the downstream user equipment. It can be seen that the use of the above-mentioned coke oven riser raw coal gas waste heat recovery device can fully recover the heat in the raw coal gas, increase the output steam temperature, and form high-quality superheated steam above 2.0MPa and 300℃~350℃, thereby reducing the generation of condensate during transportation and meeting the use needs of various users. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic structural diagram of a coke oven riser raw gas waste heat recovery device provided by an embodiment of the present invention; Figure 2 A schematic structural diagram of a combined heat exchanger of a coke oven riser raw gas waste heat recovery device provided in an embodiment of the present invention; Figure 3 A schematic structural diagram of a coke oven riser raw gas waste heat recovery device provided by another embodiment of the present invention; Figure 4 A schematic flow chart of a method for recovering waste heat from raw coal gas in a coke oven riser provided by an embodiment of the present invention; Figure 5 A schematic flow chart of a method for recovering waste heat from raw gas in a coke oven riser provided in another embodiment of the present invention.

[0019] In the figure: 1 is a combined heat exchanger; 110 is an inner tube; 120 is an outer tube; 130 is a first heat exchange pipeline; 131 is a saturated steam inlet; 132 is a superheated steam outlet; 140 is a second heat exchange pipeline; 141 is a saturated water inlet; 142 is a saturated water outlet; 2 is a steam drum; 201 is a saturated steam outlet; 202 is a water outlet; 203 is a water feed inlet; 3 is a forced circulation pump; 4 is a riser tee; 5 is a riser base; 6 is an expansion gap; 7 is a desalted water tank; 8 is a deaerator feed pump; 9 is a deaerator; 10 is a boiler feed pump. DETAILED DESCRIPTION

[0020] One of the core aspects of the present invention is to provide a coke oven riser raw gas waste heat recovery device, the structural design of which enables it to effectively recycle the waste heat of the coke oven raw gas, increase the steam temperature it generates, and reduce the generation of condensed water.

[0021] Another core of the present invention is to provide a waste heat recovery method based on the above-mentioned coke oven riser raw gas waste heat recovery device.

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figure 1 and Figure 2 , Figure 1 A schematic diagram of the structure of a coke oven riser raw gas waste heat recovery device provided by an embodiment of the present invention. Figure 2 A schematic structural diagram of a combined heat exchanger of a coke oven riser raw gas waste heat recovery device provided in an embodiment of the present invention.

[0024] The embodiment of the present invention discloses a coke oven riser raw gas waste heat recovery device, which comprises a combined heat exchanger 1, a steam drum 2 and a forced circulation pump 3.

[0025] The combined heat exchanger 1 includes an inner tube 110, an outer tube 120, a first heat exchange pipeline 130 and a second heat exchange pipeline 140. The inner tube 110 is connected between the riser tee 4 and the riser base 5 to form a raw gas supply channel between the riser tee 4 and the riser base 5. In actual application, a coke oven is equipped with dozens of risers. According to needs, the combined heat exchanger 1 can be set on all the risers or on some of them. The inner tube 110 needs to be directly connected to the raw gas at 600℃~800℃. The main components of raw gas include carbon monoxide, nitrogen oxides, and benzophenone produced under certain combustion conditions. In addition, it also contains toxic components such as sulfides and cyanides, and is corrosive to gas equipment. Therefore, the inner cylinder 110 needs to be made of high-temperature resistant and corrosion-resistant materials. Since the outer cylinder 120 does not directly contact the raw gas, the material requirements are lower than those of the inner cylinder 110. That is, the outer cylinder 120 can be made of a different material from the inner cylinder 110 to reduce costs. Of course, the inner cylinder 110 and the outer cylinder 120 can also be made of the same material.

[0026] The outer cylinder 120 is sleeved outside the inner cylinder 110, and there is a gap between the outer cylinder 120 and the inner cylinder 110. The outer cylinder 120 and the inner cylinder 110 are preferably coaxially arranged to ensure that the radial dimensions of the gap are the same along the axial direction to ensure uniform heating. Along the flow direction of the raw gas, the gap includes a first heat exchange section and a second heat exchange section. Usually, the riser is arranged vertically, and the combined heat exchanger 1 is also arranged vertically. Therefore, the first heat exchange section is located below the second heat exchange section. The first heat exchange pipeline 130 is arranged at In the first heat exchange section, the second heat exchange pipeline 140 is arranged in the second heat exchange section. It should be noted that the first heat exchange pipeline 130 and the second heat exchange pipeline 140 should be fully in contact with the outer wall of the inner tube 110 to be fully heated. The larger the contact area between the first heat exchange pipeline 130 and the second heat exchange pipeline 140 and the outer wall of the inner tube 110, the higher the heat exchange efficiency. Of course, the first heat exchange pipeline 130 and the second heat exchange pipeline 140 can be integrated with one of the inner tube 110 and the outer tube 120. The temperature resistance of the first heat exchange pipeline 130 and the second heat exchange pipeline 140 is above 500°C.

[0027] The superheated steam outlet 132 and the saturated steam outlet 201 of the drum 2 are connected to the first heat exchange pipeline 130, and the water outlet 202 of the drum 2, the forced circulation pump 3, the second heat exchange pipeline 140 and the water supply port 203 of the drum 2 are connected in series to form a water circulation loop.

[0028] Compared with the prior art, in the coke oven riser raw gas waste heat recovery device provided in the embodiment of the present invention, when in use, the liquid water in the drum 2 is transported to the second heat exchange pipeline 140 by the forced circulation pump 3, and the liquid water is heated by heat exchange with the raw gas in the second heat exchange pipeline 140 to be heated to 2.0MPa, 180℃~210℃ of liquid-gas saturated water, and then sent back to the drum 2, the liquid-gas saturated water is separated into gas and liquid in the drum 2, and the separated liquid water is transported to the second heat exchange pipeline 140 in the combined heat exchanger 1 of each riser of the coke oven by the forced circulation pump 3, and circulates continuously, and the gaseous steam separated in the drum 2 is pressed to each under the pressure of the drum 2. In the first heat exchange pipeline 130 of the combined heat exchanger 1 in the coke oven riser, the gaseous steam is converted from saturated steam of 2.0 MPa and 180°C~210°C into superheated steam of 2.0 MPa and 300°C~350°C after heat exchange with the raw gas in the first heat exchange pipeline 130. The generated superheated steam is combined and directly transported to the downstream user equipment. It can be seen that the use of the above-mentioned coke oven riser raw gas waste heat recovery device can fully recover the heat in the raw gas, increase the output steam temperature, and form high-quality superheated steam of more than 2.0 MPa and 300°C~350°C, thereby reducing the generation of condensate during transportation and meeting the use needs of various users.

[0029] like Figure 2 As shown, in one embodiment of the present application, an expansion gap 6 is provided between one of the riser tee 4 and the riser base 5 and the outer tube 120, and the other of the riser tee 4 and the riser base 5 is connected to the end of the outer tube 120. By providing the expansion gap 6 between the outer tube 120 and the riser tee 4 or the riser base 5, the axial load between the outer tube 120 and the riser tee 4 or between the outer tube 120 and the riser base 5 can be reduced, thereby reducing the deformation of the outer tube 120, the riser tee 4 or the riser base 5.

[0030] Specifically, in a specific embodiment of the present application, the expansion gap 6 is 5 mm to 10 mm.

[0031] To further optimize the above technical solution, the inner cylinder 110 is a stainless steel cylinder, specifically a 310s stainless steel cylinder, and the outer cylinder 120 is a carbon steel cylinder.

[0032] As saturated steam is output to the outside, the liquid level in the drum 2 will gradually decrease. Therefore, in one embodiment of the present application, please refer to Figure 3 , Figure 3A schematic structural diagram of a coke oven riser raw gas waste heat recovery device provided for another embodiment of the present invention, the coke oven riser raw gas waste heat recovery device also includes a water supply system, the water supply system includes a desalted water tank 7, a deoxygenation water pump 8, a deaerator 9 and a boiler feed water pump 10, the desalted water tank 7, the deoxygenation water pump 8, the deaerator 9, the boiler feed water pump 10 and the water supply port 203 of the drum 2 are connected in series in sequence, the desalted water tank 7 stores desalted water, when the drum 2 needs to be replenished with water, the deoxygenation water pump 8 sends the desalted water into the deaerator 9, and the deaerator 9 is heated to 104°C with low-pressure steam (0.6MPa, 160°C~200°C) for deoxygenation, and the desalted water is sent into the drum 2 by the boiler feed water pump 10 after deoxygenation.

[0033] In order to ensure the normal and orderly operation of the coke oven riser raw gas waste heat recovery device, in one embodiment of the present application, the coke oven riser raw gas waste heat recovery device also includes a control system, the control system includes a controller, a liquid level detection device, a saturated water temperature detection device, a saturated water pressure detection device, a steam temperature detection device and a steam pressure detection device, the liquid level detection device is used to detect the liquid level in the steam drum 2, the saturated water temperature detection device is used to detect the outlet saturated water temperature of the second heat exchange pipeline 140, the saturated water pressure detection device is used to detect the outlet saturated water pressure of the second heat exchange pipeline 140, the steam temperature detection device is used to detect the outlet steam temperature of the first heat exchange pipeline 130, and the steam pressure detection device is used to detect the outlet steam pressure of the first heat exchange pipeline 130. The controller is respectively communicated with the liquid level detection device, the saturated water temperature detection device, the saturated water pressure detection device, the steam temperature detection device, the steam pressure detection device, the steam drum 2, the boiler feed water pump 10 and the forced circulation pump 3, and the controller controls the operation of the steam drum 2, the boiler feed water pump 10 and the forced circulation pump 3 according to the detection values ​​of each detection device.

[0034] Further optimize the above technical solution, such as Figure 2 As shown, the first heat exchange pipeline 130 is spirally wound around the first heat exchange section, and the two ends of the first heat exchange pipeline 130 are respectively a saturated steam inlet 131 and a superheated steam outlet 132. Along the flow direction of the raw gas, the saturated steam inlet 131 is located upstream of the superheated steam outlet 132, and the saturated steam inlet 131 is connected to the superheated steam outlet 132 and the saturated steam outlet 201 of the drum 2, and the superheated steam outlet 132 is used to connect to user equipment. The second heat exchange pipeline 140 is spirally wound around the second heat exchange section, and the two ends of the second heat exchange pipeline 140 are respectively a saturated water inlet 141 and a saturated water outlet 142. Along the flow direction of the raw gas, the saturated water inlet 141 is located upstream of the saturated water outlet 142, and the saturated water inlet 141 is connected to the forced circulation pump 3, and the saturated water outlet 142 is connected to the water supply port 203 of the drum 2.

[0035] The present application also provides a waste heat recovery method based on the coke oven riser raw gas waste heat recovery device described in the above embodiment, such as Figure 4 As shown, the waste heat recovery method comprises the steps of: The liquid water in the drum 2 is transported to the second heat exchange pipeline 140 of the combined heat exchanger 1 of each riser of the coke oven through the forced circulation pump 3. The liquid water exchanges heat with the raw gas passing through the combined heat exchanger 1 in the second heat exchange pipeline 140 to form liquid-vapor saturated water of a first preset pressure and a first preset temperature. The liquid-vapor saturated water returns to the drum 2 for vapor-liquid separation. The separated liquid water is then transported to the second heat exchange pipeline 140 of the combined heat exchanger 1 of each riser of the coke oven through the forced circulation pump 3 for continuous circulation.

[0036] In the above embodiment, a coke oven has about 60 risers, and each riser is arranged with a combined heat exchanger 1. Therefore, a coke oven should have about 60 combined heat exchangers 1. Liquid water absorbs heat in the second heat exchange pipeline 140 to form liquid-vapor saturated water. The first preset pressure is 2.0 MPa, and the first preset temperature is 180°C~210°C. The liquid-vapor saturated water is separated into liquid and liquid in the steam drum 2 to form liquid water and gaseous steam.

[0037] The gaseous steam in the drum 2 is transported to the first heat exchange pipeline 130 of the combined heat exchanger 1 of each riser of the coke oven under the action of the pressure in the drum 2. The gaseous steam exchanges heat with the raw gas passing through the combined heat exchanger 1 in the first heat exchange pipeline 130 to form superheated steam of a second preset pressure and a second preset temperature. The superheated steam in the combined heat exchanger 1 of each riser of the coke oven is combined and transported to the user equipment.

[0038] In the above steps, the gaseous steam separated in the drum 2 is pressed into the first heat exchange pipeline 130 of the combined heat exchanger 1 in each coke oven riser under the pressure of the drum 2, and after absorbing the heat of the raw gas, it is converted from saturated steam of 2.0 MPa and 180°C to 210°C into superheated steam of 2.0 MPa and 300°C to 350°C.

[0039] Further optimizing the above technical solution, it can be foreseen that as the drum 2 outputs saturated steam, the liquid level in the drum 2 will gradually decrease. Figure 5 As shown, the waste heat recovery method also includes the steps of: The liquid level in the drum 2 is detected. If the liquid level in the drum 2 drops to a preset level, the desalted water in the desalted water tank 7 is transported to the deaerator 9 for deoxygenation through the deoxygenation feed water pump 8, and the desalted water after deoxygenation is transported to the drum 2 through the boiler feed water pump 10 to avoid the liquid level in the drum 2 being too low, thereby ensuring the normal and orderly operation of the entire waste heat recovery device.

[0040] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0041] It should be understood that the use of "system", "device", "unit" and / or "module" in this application is only a method for distinguishing different components, elements, parts, parts or assemblies at different levels. However, if other words can achieve the same purpose, the word can be replaced by other expressions.

[0042] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The elements defined by the sentence "includes a..." do not exclude the existence of other identical elements in the process, method, commodity or device that includes the elements.

[0043] In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0044] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0045] If a flow chart is used in the present application, the flow chart is used to illustrate the operations performed by the system according to the embodiment of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, each step can be processed in reverse order or simultaneously. At the same time, other operations can also be added to these processes, or a certain step or several steps of operations can be removed from these processes.

[0046] It should also be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such articles or devices. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0047] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A coke oven riser raw gas waste heat recovery device, characterized in that: It includes a combined heat exchanger, a steam drum and a forced circulation pump; The combined heat exchanger comprises an inner tube, an outer tube, a first heat exchange pipeline and a second heat exchange pipeline. The inner tube is connected between the riser tee and the riser base to form a raw gas supply channel between the riser tee and the riser base. The outer tube is sleeved outside the inner tube. There is a gap between the outer tube and the inner tube. Along the flow direction of the raw gas, the gap includes a first heat exchange section and a second heat exchange section. The first heat exchange pipeline is arranged in the first heat exchange section, and the second heat exchange pipeline is arranged in the second heat exchange section. The saturated steam outlet of the steam drum is in communication with the first heat exchange pipeline; The water outlet of the drum, the forced circulation pump, the second heat exchange pipeline and the water supply port of the drum are connected in series to form a water circulation loop.

2. The coke oven riser raw gas waste heat recovery device according to claim 1, characterized in that: An expansion gap is provided between one of the riser pipe tee and the riser pipe base and the outer tube, and the other of the riser pipe tee and the riser pipe base is connected to the end of the outer tube.

3. The coke oven riser raw gas waste heat recovery device according to claim 2, characterized in that: The expansion gap is 5 mm to 10 mm.

4. The coke oven riser raw gas waste heat recovery device according to any one of claims 1 to 3, characterized in that: The inner cylinder is a stainless steel cylinder, and the outer cylinder is a carbon steel cylinder.

5. The coke oven riser raw gas waste heat recovery device according to any one of claims 1 to 3, characterized in that: It also includes a water supply system, which includes a desalted water tank, a deoxygenated water feed pump, a deaerator and a boiler feed pump, and the desalted water tank, the deoxygenated water feed pump, the deaerator, the boiler feed pump and the water feed port of the steam drum are connected in series in sequence.

6. The coke oven riser raw gas waste heat recovery device according to claim 5, characterized in that: It also includes a control system, which includes a controller, a liquid level detection device, a saturated water temperature detection device, a saturated water pressure detection device, a steam temperature detection device and a steam pressure detection device. The liquid level detection device is used to detect the liquid level in the steam drum, the saturated water temperature detection device is used to detect the outlet saturated water temperature of the second heat exchange pipeline, the saturated water pressure detection device is used to detect the outlet saturated water pressure of the second heat exchange pipeline, the steam temperature detection device is used to detect the outlet steam temperature of the first heat exchange pipeline, and the steam pressure detection device is used to detect the outlet steam pressure of the first heat exchange pipeline. The controller is respectively connected to the liquid level detection device, the saturated water temperature detection device, the saturated water pressure detection device, the steam temperature detection device, the steam pressure detection device, the steam drum, the boiler feed pump and the forced circulation pump for communication.

7. The coke oven riser raw gas waste heat recovery device according to any one of claims 1 to 3, characterized in that: The first heat exchange pipeline is spirally coiled around the first heat exchange section. The two ends of the first heat exchange pipeline are respectively a saturated steam inlet and a superheated steam outlet. Along the flow direction of the raw gas, the saturated steam inlet is located upstream of the superheated steam outlet. The saturated steam inlet is connected to the saturated steam outlet of the steam drum, and the superheated steam outlet is used to connect to user equipment.

8. The coke oven riser raw gas waste heat recovery device according to any one of claims 1 to 3, characterized in that: The second heat exchange pipeline is spirally coiled around the second heat exchange section, and the two ends of the second heat exchange pipeline are respectively a saturated water inlet and a saturated water outlet. Along the flow direction of the raw gas, the saturated water inlet is located upstream of the saturated water outlet, the saturated water inlet is connected to the forced circulation pump, and the saturated water outlet is connected to the water supply port of the steam drum.

9. A waste heat recovery method based on the coke oven riser raw gas waste heat recovery device according to any one of claims 1 to 8, characterized in that: Includes steps: The liquid water in the drum is transported to the second heat exchange pipeline of the combined heat exchanger of each riser of the coke oven through a forced circulation pump, and the liquid water exchanges heat with the raw coal gas passing through the combined heat exchanger in the second heat exchange pipeline to form liquid-gas saturated water of a first preset pressure and a first preset temperature, and the liquid-gas saturated water returns to the drum for vapor-liquid separation, and the separated liquid water is then transported to the second heat exchange pipeline of the combined heat exchanger of each riser of the coke oven through a forced circulation pump, and circulates continuously; The gaseous steam in the steam drum is transported to the first heat exchange pipeline of the combined heat exchanger of each riser of the coke oven under the action of the pressure in the steam drum. The gaseous steam exchanges heat with the raw coal gas passing through the combined heat exchanger in the first heat exchange pipeline to form superheated steam of a second preset pressure and a second preset temperature. The superheated steam in the combined heat exchangers of each riser of the coke oven is combined and transported to the user equipment.

10. The waste heat recovery method according to claim 9, characterized in that: Also includes the steps: The liquid level in the drum is detected. If the liquid level in the drum drops to a preset level, the desalted water in the desalted water tank is transported to the deaerator for deoxygenation through the deaerator feed water pump, and the desalted water after deoxygenation is transported to the drum through the boiler feed water pump.

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