Coal gas fine desulfurization section heat recovery system for iron and steel enterprises

Abstract

The invention provides a steel enterprise coal gas fine desulfurization section heat recovery system, which relates to the technical field of coal gas fine desulfurization, and comprises a demisting tower, a hydrolysis tower, a second cooler, a desulfurization tower, a coal gas pipeline and a heat pump system, coal gas sequentially flows through a first cooler, a demister and a heater of the demisting tower, then enters the hydrolysis tower and a second cooler and is finally output after being treated by the desulfurizing tower, and the heat pump system comprises a compressor, an evaporator, a condenser, an electronic expansion valve and a refrigerant pipe and can provide heat for the heater and provide cooling capacity for the first cooler and the second cooler. And efficient cyclic utilization of heat energy is achieved. In addition, the system is further provided with a steam heating system and a cold water system for standby application, and an air cooling radiator and a speed regulation fan are adopted to achieve heat regulation and control. The invention solves the problem of energy waste in the cooling-heating-recooling process in the traditional process, and has the advantages of obvious energy-saving effect, high energy efficiency ratio, compact system structure, low improvement cost and the like.

Description

Technical Field

[0001] This invention relates to the field of coal gas desulfurization technology, and more particularly to a heat recovery system for the coal gas desulfurization section of an iron and steel enterprise. Background Technology

[0002] Steel companies commonly employ refined desulfurization processes during coal gas purification to ensure safety and environmental compliance in subsequent processes. Traditional refined desulfurization systems typically involve multi-stage treatment and energy exchange: first, the coal gas, with an initial temperature not exceeding 50 degrees Celsius, is preliminarily cooled in a primary cooler to remove some moisture; then, a demister further removes liquid impurities; next, a heater raises the gas temperature to 70–90 degrees Celsius to facilitate subsequent hydrolysis; after the conversion of organic sulfides in the hydrolysis tower, the gas temperature is further reduced to approximately 35–50 degrees Celsius in a secondary cooler before finally being fed into a desulfurization tower for deep desulfurization. In this process, the primary and secondary coolers generally rely on externally supplied cooling water at approximately 33 degrees Celsius as a cold source, while the heaters require saturated steam at a pressure of approximately 3–4 bar for heating.

[0003] However, this "cooling-heating-cooling" process presents significant energy efficiency problems. On the one hand, the two cooling processes consume large amounts of low-temperature cooling water; on the other hand, the intermediate heating stage requires a continuous supply of medium-temperature steam, resulting in high demand for external cold and heat sources, high operating energy consumption, and high costs. How to fully utilize the inherent temperature difference energy within the system and reduce dependence on external energy sources while ensuring desulfurization effectiveness has become a key technical challenge that urgently needs to be addressed in this field. Existing systems lack effective internal energy recovery mechanisms, leading to energy waste during the cooling and heating processes.

[0004] Therefore, there is an urgent need to develop a new and efficient heat energy recovery system to solve this problem. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a heat recovery system for the coal gas desulfurization stage in steel enterprises. By introducing a heat pump system into the coal gas desulfurization process, this invention achieves self-sufficiency and recycling of heating and cooling energy, significantly reducing external energy consumption.

[0006] To achieve the above objectives, the present invention provides a heat recovery system for the desulfurization section of coal gas in steel enterprises, comprising a demister, a hydrolysis tower, a second cooler, a desulfurization tower, and a coal gas pipeline. Coal gas passes sequentially through the demister, hydrolysis tower, and desulfurization tower via the coal gas pipeline. The demister includes a first cooler, a demister, and a heater. Coal gas passes sequentially through the first cooler, the demister, and the heater. The system also includes a heat pump system, which provides heat to the heater and cooling to the first and second coolers. The heat pump system includes a compressor, an evaporator, a condenser, an electronic expansion valve, and refrigerant pipes. The refrigerant pipes are connected in sequence to the compressor, condenser, electronic expansion valve, and evaporator to form a closed loop. The condenser is installed inside the heater and is used to directly provide heat to the heater; A heat exchange coil is installed outside the evaporator, and the heat exchange coil is connected to a hydraulic center. The hydraulic center supplies cold water to the first cooler and the second cooler through water pipes.

[0007] Furthermore, two evaporators are provided, installed in the first cooler and the second cooler respectively, for directly absorbing heat during the gas cooling process.

[0008] Furthermore, it also includes a steam heating system connected to the heater as a backup heating device; the steam heating system includes a coil device through which steam is supplied.

[0009] Furthermore, it also includes a cooling water system, which is connected to the first cooler and the second cooler via water pipes and serves as a backup cooling device; the cooling water system includes a coil device through which cooling water flows.

[0010] Furthermore, it also includes an air-cooled radiator and a speed-regulating fan. The air-cooled radiator is installed between the condenser and the electronic expansion valve to regulate the amount of heat output to the heater.

[0011] Furthermore, an electric regulating valve is installed on the refrigerant pipe to adjust the refrigerant flow rate.

[0012] Furthermore, the water pipe is equipped with an electric regulating valve for adjusting the flow rate of chilled water.

[0013] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: 1. This invention provides a heat recovery system for the desulfurization stage of coal gas in steel enterprises. By introducing a heat pump system, it cleverly utilizes the significant energy difference inherent in the "cooling-heating-recooling" process of desulfurization. The heat absorbed during cooling the coal gas is used to improve its quality and then reused to heat the coal gas, forming an internal energy cycle. This replaces the traditional system's complete reliance on external steam heating and cooling water cooling, significantly reducing production costs.

[0014] 2. The present invention provides a heat recovery system for the desulfurization section of coal gas in steel enterprises. By integrating heating and cooling functions into a heat pump system for coordinated operation, it not only avoids unnecessary energy waste, but also makes the overall energy efficiency ratio of the system much higher than that of the traditional separate supply method.

[0015] 3. The heat recovery system for the coal gas desulfurization section of an iron and steel enterprise provided by this invention, by equipping a temperature control unit consisting of an air-cooled radiator and a speed-regulating fan, can finely adjust the heat output to the heater according to actual operating conditions, ensuring the stable operation of subsequent hydrolysis and desulfurization sections. At the same time, the original steam heating system and cooling water system are retained as backups, allowing for seamless switching during main system maintenance or fluctuations, ensuring continuous and safe operation of the entire coal gas desulfurization process. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of a heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to Embodiment 2 of the present invention; Figure 3 These are data comparison diagrams of Embodiment 1, Embodiment 2, and a comparative example of a heat recovery system for the coal gas desulfurization section of an iron and steel enterprise as described in this invention.

[0018] In the diagram: 1. First cooler; 2. Demister; 3. Heater; 4. Hydrolysis tower; 5. Second cooler; 6. Desulfurization tower; 7. Hydraulic center; 8. Compressor; 9. Electronic expansion valve; 10. Evaporator; 11. Steam system; 12. Cold water system; 13. Air-cooled radiator; 14. Variable speed fan. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0023] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0024] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0025] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0026] Example 1 like Figure 1 As shown, the present invention provides a heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise, comprising: a demister, a hydrolysis tower 4, a second cooler 5, a desulfurization tower 6, and a coal gas pipeline. The coal gas passes through the demister, hydrolysis tower 4, and desulfurization tower 6 sequentially via the coal gas pipeline. The demister includes a first cooler 1, a demister 2, and a heater 3. The coal gas passes through the first cooler 1, the demister 2, and the heater 3 sequentially. The system includes a heat pump system, which provides heat to the heater 3 and cooling to the first cooler 1 and the second cooler 5.

[0027] The heat pump system includes a compressor 8, an evaporator 10, a condenser, an electronic expansion valve 9, and refrigerant pipes, which are connected in sequence to the compressor 8, evaporator 10, condenser, electronic expansion valve 9, and evaporator 10.

[0028] Evaporator 10 is installed inside heater 3. Heat exchange coil is installed outside evaporator 10. Heat exchange coil is connected to hydraulic center 7. Hydraulic center 7 supplies cold water to first cooler 1 and second cooler 5 through water pipe.

[0029] Furthermore, it also includes an air-cooled radiator 13 and a speed-regulating fan 14, with the air-cooled radiator 13 installed between the condenser and the electronic expansion valve 9.

[0030] The air-cooled radiator 13 and the speed-regulating fan 14 are used to adjust the amount of heat output to the gas heater 3 to ensure stable system operation.

[0031] Both the refrigerant pipes and water pipes are equipped with electric regulating valves to adjust the flow rate of refrigerant and chilled water.

[0032] Furthermore, it also includes a steam heating system 11 and a cold water system 12 as backup heating and cooling systems. The steam system includes a coil device through which steam is supplied, and the cold water system 12 includes a coil device through which cold water is supplied. The steam heating system 11 is connected to the heater 3, and the cold water system 12 is connected to the first cooler 1 and the second cooler 5.

[0033] Application method of this embodiment: During system operation, the heat pump system operates. The evaporator absorbs heat and supplies chilled water to the hydraulic center 7 through heat exchange coils. The hydraulic center 7 then supplies chilled water to the first cooler 1 and the second cooler 5. The evaporator 10 releases heat and is installed inside the heater 3. When the blast furnace gas, not exceeding 50°C, enters the first cooler 1, it undergoes a first cooling process. Then, it enters the demister 2 to remove moisture, followed by heating to 70-90°C in the heater 3. Next, it enters the hydrolysis tower 4 for further processing, then enters the second cooler 5 for a second cooling process to 35-50°C. Finally, it is desulfurized by the desulfurization tower 6 and discharged to the next production port. The steam heating system 11 and the chilled water system 12 serve as backup equipment for heating and cooling.

[0034] Example 2 like Figure 2 As shown, the present invention provides a heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise, comprising: a demister, a hydrolysis tower 4, a second cooler 5, a desulfurization tower 6, and a coal gas pipeline. The coal gas passes through the demister, hydrolysis tower 4, and desulfurization tower 6 sequentially via the coal gas pipeline. The demister includes a first cooler 1, a demister 2, and a heater 3. The coal gas passes through the first cooler 1, the demister 2, and the heater 3 sequentially. The system includes a heat pump system, which provides heat to the heater 3 and cooling to the first cooler 1 and the second cooler 5.

[0035] The heat pump system includes a compressor 8, an evaporator 10, a condenser, an electronic expansion valve 9, and refrigerant pipes, which are connected in sequence to the compressor 8, the electronic expansion valve 9, the condenser, and the evaporator 10.

[0036] Evaporator 10 is installed inside heater 3. There are two evaporators 10, which are installed in the first cooler 1 and the second cooler 5 respectively.

[0037] Furthermore, it includes an air-cooled radiator 13 and a speed-regulating fan 14, with the air-cooled radiator 13 installed between the condenser and the electronic expansion valve 9.

[0038] The air-cooled radiator 13 and the speed-regulating fan 14 are used to adjust the amount of heat output to the gas heater 3 to ensure stable system operation.

[0039] An electric regulating valve is installed on the refrigerant pipe to adjust the refrigerant flow rate.

[0040] Furthermore, a backup steam heating system 11 is included. The steam system includes a coil assembly through which steam is supplied. The steam heating system 11 is connected to the heater 3.

[0041] Application method of this embodiment: During system operation, the heat pump system operates. Evaporator 10 absorbs heat and is installed inside the first cooler 1 and the second cooler 5; evaporator 10 releases heat and is installed inside the heater 3. When blast furnace gas at a temperature not exceeding 50°C enters the first cooler 1, it undergoes a first cooling process. Then, it enters the demister 2 to remove moisture, followed by heating to 70-90°C in the heater 3. Next, it enters the hydrolysis tower 4 for further processing, then enters the second cooler 5 for a second cooling process to 35-50°C. Finally, after desulfurization in the desulfurization tower 6, it is discharged to the next production port. Steam heating system 11 serves as a backup heating device.

[0042] Comparative Example The comparative example is a coal gas desulfurization section system in an iron and steel enterprise, including a demister, a hydrolysis tower 4, a second cooler 5, a desulfurization tower 6, and coal gas pipelines. Coal gas passes sequentially through the demister, hydrolysis tower 4, and desulfurization tower 6 via the coal gas pipelines. The demister includes a first cooler 1, a demister 2, and a heater 3. A steam heating system 11 and a cold water system 12 are also included. The steam system includes a coil device for supplying steam, and the cold water system 12 includes a coil device for supplying cold water. The steam heating system 11 is connected to the heater 3, and the cold water system 12 is connected to the first cooler 1 and the second cooler 5.

[0043] The steam heating system 11 provides heat to the heater 3 through external high-temperature steam, and the cold water system 12 provides cooling to the first cooler 1 and the second cooler 5 through external cooling water.

[0044] like Figure 3 As shown, the energy savings rates of Examples 1 and 2 compared to the comparative example are 40.49% and 45.36%, respectively. This demonstrates the effective energy and production cost savings.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise, comprising: The system comprises a demister, a hydrolysis tower, a second cooler, a desulfurization tower, and a gas pipeline. Gas flows sequentially through the demister, hydrolysis tower, and desulfurization tower via the gas pipeline. The demister includes a first cooler, a demister, and a heater. Gas flows sequentially through the first cooler, the demister, and the heater. The system is characterized by further including a heat pump system, which provides heat to the heater and cooling to the first and second coolers. The heat pump system includes a compressor, an evaporator, a condenser, an electronic expansion valve, and refrigerant pipes. The refrigerant pipes are connected in sequence to the compressor, condenser, electronic expansion valve, and evaporator to form a closed loop. The condenser is installed inside the heater and is used to directly provide heat to the heater; A heat exchange coil is installed outside the evaporator, and the heat exchange coil is connected to a hydraulic center. The hydraulic center supplies cold water to the first cooler and the second cooler through water pipes.

2. The heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to claim 1, characterized in that, Two evaporators are provided, installed in the first cooler and the second cooler respectively, for directly absorbing heat during the gas cooling process.

3. The heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to claim 1, characterized in that, It also includes a steam heating system connected to the heater as a backup heating device; the steam heating system includes a coil device through which steam is supplied.

4. A heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to claim 1, characterized in that, It also includes a chilled water system, which is connected to the first cooler and the second cooler via water pipes and serves as a backup cooling device; the chilled water system includes a coil device through which chilled water flows.

5. A heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to claim 1, characterized in that, It also includes an air-cooled radiator and a speed-regulating fan. The air-cooled radiator is installed between the condenser and the electronic expansion valve to regulate the amount of heat output to the heater.

6. A heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to claim 1, characterized in that, An electric regulating valve is installed on the refrigerant pipe to adjust the refrigerant flow rate.

7. A heat recovery system for the desulfurization section of coal gas in an iron and steel enterprise according to claim 1, characterized in that, The water pipe is equipped with an electric regulating valve to adjust the flow rate of chilled water.

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