Ionic membrane caustic soda hydrogen waste heat recovery device
The closed-loop system consisting of a heat exchanger and a refrigerator solves the problem of waste heat from high-temperature wet hydrogen, realizes waste heat recovery and separation and utilization of water vapor, and improves production efficiency and economy.
Patent Information
- Application Number
- CN202422648633.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-31
AI Technical Summary
During the production of ion-exchange membrane caustic soda, a large amount of waste heat from high-temperature wet hydrogen is wasted, resulting in energy loss and increased production costs. Even after the purity of hydrogen is improved, additional cooling treatment is still required, affecting production efficiency.
A closed circulation system consisting of a heat exchanger and a refrigerator is used. After heat exchange with high-temperature wet hydrogen through the heat exchanger, the circulating liquid enters the refrigerator for cooling and then returns to the heat exchanger for heat exchange again to recover waste heat. Water vapor is condensed and separated in the heat exchanger, and the circulating liquid is used for other processes.
The effective recovery and utilization of waste heat from high-temperature wet hydrogen is achieved, which reduces equipment costs, improves production efficiency, separates and recycles water vapor, and improves overall production economy.
Smart Images
Figure CN223345688U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of waste heat recovery of ion membrane caustic soda, and particularly relates to a hydrogen waste heat recovery device of ion membrane caustic soda. Background Art
[0002] Ion-exchange membrane caustic soda is produced by electrolyzing salt water with an ion exchange membrane. The main principle is that the cation exchange membrane used has a special selective permeability, which only allows cations to pass through while blocking anions and gases. This prevents the anode product Cl2 and the cathode product H2 from mixing, which may cause an explosion. It also prevents the anode product from reacting with another cathode product NaOH to form NaClO, which affects the purity of the caustic soda.
[0003] In the production process of ion-exchange membrane caustic soda, electrolysis is a key link. Through electrolysis, a variety of products including hydrogen can be produced. However, the hydrogen produced in this process often has a high temperature and a large amount of water, and also contains trace amounts of alkaline mist. Specifically, the temperature of the hydrogen produced by electrolysis is usually as high as about 85°C, and its water content can account for about 80wt% of the total weight. In addition, there are trace amounts of alkaline mist mixed in the hydrogen, and these impurities pose certain obstacles to the subsequent use of hydrogen. In order to deal with these impurities, the method currently commonly used in the industry is to wash and cool the wet hydrogen. The main purpose of this step is to remove most of the water and alkaline mist in the hydrogen to improve the purity of the hydrogen so that it can meet the requirements of subsequent applications. The hydrogen after washing and cooling will be further compressed and cooled for secondary cooling so that it can be used for the synthesis of HCl gas or as fuel.
[0004] However, while this treatment method has achieved significant results in improving hydrogen purity, it also brings with it a significant problem: the significant waste of waste heat from the high-temperature wet hydrogen. For example, a plant with an annual production capacity of 400,000 tons of ion-exchange membrane caustic soda produces approximately 7 tons of wet hydrogen per hour during the electrolysis process. The heat carried by this wet hydrogen is enormous, with an estimated calorific value of approximately 2,200 kilowatts. This wasted heat not only results in energy loss but also increases production costs, reducing the overall economic viability of production.
[0005] Therefore, effectively utilizing this wasted waste heat has become a pressing technical challenge in the current production of ion-exchange membrane caustic soda. To reduce caustic soda plant operating costs, lower energy consumption, and minimize carbon emissions, technological improvements to recycle and utilize waste heat from high-temperature wet hydrogen will not only improve energy efficiency and lower production costs, but also contribute to the sustainable development of the ion-exchange membrane caustic soda industry. Utility Model Content
[0006] The purpose of this utility model is to address the above-mentioned shortcomings and provide an ion-exchange membrane caustic soda hydrogen waste heat recovery device, which realizes the recovery and utilization of the waste heat of the high-temperature wet hydrogen in the ion-exchange membrane caustic soda, and also recovers and utilizes the water vapor in the high-temperature wet hydrogen. To achieve the above-mentioned purpose, the utility model provides the following technical solutions:
[0007] An ion-exchange membrane caustic soda hydrogen waste heat recovery device comprises a heat exchanger and a refrigerator; the heat exchanger and refrigerator are connected via a circulation pipeline; the heat exchanger receives high-temperature, wet hydrogen from the electrolysis process and indirectly exchanges heat between the hydrogen and a circulating liquid in the heat exchanger; after the circulating liquid in the heat exchanger is heated by heat exchange, it flows through the circulation pipeline to the refrigerator for cooling; the cooled circulating liquid then flows back through the circulation pipeline to the heat exchanger for further heat exchange with the hydrogen, forming a closed cycle.
[0008] Furthermore, the heat exchanger is a shell and tube heat exchanger.
[0009] Furthermore, the shell of the heat exchanger is provided with a through hole; the circulation pipeline is connected with the inside of the heat exchanger shell through the through hole; and a circulation pump is provided on the circulation pipeline.
[0010] Furthermore, it also includes a liquid storage tank; the liquid storage tank is located below the heat exchanger; the liquid storage tank is connected to the heat exchanger through a first pipeline.
[0011] Furthermore, a gas pipeline is provided on the first pipeline; the outlet of the gas pipeline is upward.
[0012] Furthermore, a drying unit is provided on the gas pipeline; a desiccant is provided in the drying unit.
[0013] Furthermore, the liquid storage tank is connected to the refrigerator via a second pipeline; a liquid pump is provided on the second pipeline; and a liquid outlet is provided at the bottom of the refrigerator.
[0014] Furthermore, it also includes a controller and a temperature probe; the heat exchanger and the refrigerator are respectively provided with temperature probes; the controller is electrically connected to the temperature probe, the circulation pump and the liquid pump.
[0015] The beneficial effects of the utility model are:
[0016] The utility model discloses a waste heat recovery device for hydrogen gas from an ion membrane caustic soda, comprising a heat exchanger and a refrigerator; the heat exchanger and the refrigerator are connected via a circulation pipeline; the heat exchanger receives high-temperature wet hydrogen gas from the electrolysis process and performs heat exchange between the hydrogen gas and a circulating liquid in the heat exchanger; after the temperature of the circulating liquid in the heat exchanger is increased through heat exchange, it flows through the circulation pipeline into the refrigerator for cooling, and the cooled circulating liquid then flows through the circulation pipeline into the heat exchanger for heat exchange with the hydrogen gas again. The waste heat recovery device for hydrogen gas from an ion membrane caustic soda not only recovers and utilizes the waste heat of the high-temperature wet hydrogen gas from the ion membrane caustic soda, but also separates the cooled hydrogen gas into gas and liquid, and recovers and utilizes the separated liquid. The utility model has a simple structure, which not only improves production efficiency but also reduces equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the utility model ion membrane caustic soda hydrogen waste heat recovery device;
[0018] In the accompanying drawings: 1-heat exchanger, 2-refrigeration machine, 3-circulation pipeline, 4-liquid storage tank, 5-first pipeline, 6-gas pipeline, 7-drying unit, 8-second pipeline, 9-circulation pump, 10-liquid pump, 11-liquid outlet, 12-refrigerated return pipe, 13-refrigerated water supply pipe. DETAILED DESCRIPTION
[0019] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.
[0020] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of the stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.
[0021] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teachings of the example embodiments.
[0022] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inside", "outside", "below", "beneath", "above", "above", etc. Such spatially relative terms are meant to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, then an element described as "below other elements or features" or "below other elements or features" will then be oriented as "above other elements or features" or "above other elements or features". Thus, the example term "below..." can include both above and below orientations. The device can be oriented otherwise (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein are interpreted accordingly.
[0023] Example 1:
[0024] See attached Figure 1, showing a schematic diagram of the ion-exchange membrane caustic soda hydrogen waste heat recovery device of the present invention. The ion-exchange membrane caustic soda hydrogen waste heat recovery device includes a heat exchanger 1 and a refrigerator 2, which are connected by a circulation pipeline 3. The high-temperature wet hydrogen generated during the ion-exchange membrane caustic soda electrolysis process enters the heat exchanger 1 from the top inlet, undergoing indirect heat exchange with the low-temperature circulating liquid in the heat exchanger 1. The high-temperature wet hydrogen cools down and flows out from the bottom outlet of the heat exchanger 1. After the low-temperature circulating liquid in the heat exchanger 1 is heated by heat exchange, it enters the refrigerator 2 through the circulation pipeline 3 for cooling. The cooled circulating liquid then returns to the heat exchanger 1 through the circulation pipeline 3, where it again undergoes heat exchange with the high-temperature wet hydrogen in the heat exchanger 1, forming a closed cycle. The ion-exchange membrane caustic soda hydrogen waste heat recovery device of the utility model recovers and utilizes the waste heat of the high-temperature wet hydrogen generated in the ion-exchange membrane caustic soda through the heat exchanger 1 and the refrigerator 2, without the need for additional consumption of circulating water for cooling. After the high-temperature wet hydrogen undergoes heat exchange through the heat exchanger 1, the temperature is reduced while the water vapor in the hydrogen is condensed and separated, and flows out from the bottom outlet of the heat exchanger 1 together with the hydrogen. The device has a simple structure, which not only improves production efficiency but also reduces equipment cost and increases the test accuracy of the equipment.
[0025] Specifically, heat exchanger 1 is a shell-and-tube heat exchanger 1, the most widely used type of heat exchanger 1 in chemical production. It is primarily composed of a shell, tube sheets, heat exchange tubes, headers, baffles, etc. During heat exchange, high-temperature wet hydrogen enters the heat exchange tubes through the connecting pipe at the top header of the shell-and-tube heat exchanger 1, flows through the tubes, and then flows out through the outlet pipe at the other end of the header. Upper and lower through holes are provided on the shell, and the circulation pipeline 3 is connected to the interior of the shell and tube heat exchanger 1 through the upper and lower through holes. Circulation pumps 9 are provided on the upper and lower pipelines of the circulation pipeline 3. After the low-temperature circulating liquid in the shell of the shell and tube heat exchanger 1 is heat-exchanged with the high-temperature wet hydrogen in the heat exchange tube, the circulation pump 9 of the upper pipeline of the circulation pipeline 3 is started to drive the circulating liquid to flow from the circulation pipeline 3 into the refrigerator 2. After cooling in the refrigerator 2, the circulation pump 9 of the lower pipeline of the circulation pipeline 3 is started again. The circulating liquid then returns to the heat exchanger 1 through the lower pipeline of the circulation pipeline 3 and again exchanges heat with the high-temperature wet hydrogen in the heat exchanger 1.
[0026] Specifically, refrigerator 2 is a lithium bromide refrigerator, which utilizes the principle of heat absorption by the evaporation of lithium bromide to generate refrigeration. The circulating liquid in heat exchanger 1 heats up after heat exchange and flows into refrigerator 2 through circulation line 3. This raises the ambient temperature of the lithium bromide in refrigerator 2, causing the lithium bromide to evaporate and absorb heat, thereby lowering the temperature of the circulating liquid.
[0027] Specifically, a liquid storage tank 4 is provided below heat exchanger 1. Liquid storage tank 4 is connected to heat exchanger 1 via a first pipeline 5. A gas pipeline 6 is provided on first pipeline 5. The outlet of gas pipeline 6 faces upward and is connected to other pipelines to collect the produced hydrogen. After the high-temperature wet hydrogen undergoes heat exchange through heat exchanger 1, its temperature decreases, and the water vapor in the hydrogen is condensed and separated to form a liquid. This liquid flows out of the bottom outlet of heat exchanger 1 along with the hydrogen. The condensed liquid flows through first pipeline 5 into liquid storage tank 4 below for recovery, while the hydrogen flows upward from gas pipeline 6 into other pipelines. A drying unit 7 is also provided on gas pipeline 6. Drying unit 7 contains a desiccant, and the gas is further dried by drying unit 7.
[0028] Specifically, because the liquid in liquid storage tank 4 is relatively hot, a second pipe 8 connects liquid storage tank 4 and refrigerator 2. A liquid pump 10 is also provided on second pipe 8, and a liquid outlet 11 is provided at the bottom of refrigerator 2. After liquid storage tank 4 has recovered a certain amount of liquid, liquid pump 10 is turned on, driving the liquid in liquid storage tank 4 to flow into the refrigerant for further cooling. The liquid then flows out of liquid outlet 11 at the bottom of refrigerator 2 for use in other processes.
[0029] Specifically, chiller 2 is equipped with a chilled water return pipe 12 and a chilled water supply pipe 13. When chiller 2 is operating, chilled water at a temperature of approximately 10°C is introduced through chilled water return pipe 12. This water flows into chiller 2, further cooling it to a temperature below 7°C. The chilled water then flows out of chilled water supply pipe 13. This chilled water can be used for electrolytic cell replenishment, salt treatment, and other processes. By recovering hydrogen waste heat through the chiller, chilled water is produced, eliminating the need for separate equipment to produce chilled water and reducing power consumption for other equipment.
[0030] Specifically, it also includes a controller and a temperature sensor. The temperature sensor is respectively provided in the heat exchanger 1 and the refrigerator 2. The temperature sensor transmits the measured temperature to the controller, and the controller can control the start-up of the circulation pump 9 and the liquid pump 10.
[0031] All technical features in this embodiment can be freely combined according to actual needs. The above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, and all of these should be included in the scope of the claims of the present invention. The technologies, shapes, and structural parts not described in detail in this utility model are all well-known technologies.
[0032] The above embodiments are preferred implementation schemes of the present invention. In addition, other implementation schemes are also included. Any obvious replacement without departing from the concept of the present technical solution is within the protection scope of the present invention.
Claims
1. An ion-exchange membrane caustic soda hydrogen waste heat recovery device, characterized by: The invention comprises a heat exchanger (1) and a refrigerator (2); the heat exchanger (1) and the refrigerator (2) are connected via a circulation pipeline (3); the heat exchanger (1) receives high-temperature and wet hydrogen from the electrolysis process, and performs indirect heat exchange between the hydrogen and the circulating liquid in the heat exchanger (1); after the circulating liquid in the heat exchanger (1) is heated by heat exchange, it flows to the refrigerator (2) through the circulation pipeline (3) for cooling, and the cooled circulating liquid flows back to the heat exchanger (1) through the circulation pipeline (3) to perform heat exchange with the hydrogen again, thereby forming a closed cycle.
2. The ion-exchange membrane caustic soda hydrogen waste heat recovery device according to claim 1, characterized in that: The heat exchanger (1) is a shell-and-tube heat exchanger.
3. The ion-exchange membrane caustic soda hydrogen waste heat recovery device according to claim 1, characterized in that: The shell of the heat exchanger (1) is provided with a through hole; the circulation pipeline (3) is connected to the inside of the shell of the heat exchanger (1) through the through hole; and a circulation pump (9) is provided on the circulation pipeline (3).
4. The ion-exchange membrane caustic soda hydrogen waste heat recovery device according to claim 3, characterized in that: It also includes a liquid storage tank (4); the liquid storage tank (4) is located below the heat exchanger (1); the liquid storage tank (4) is connected to the heat exchanger (1) via a first pipeline (5).
5. The ion-exchange membrane caustic soda hydrogen waste heat recovery device according to claim 4, characterized in that: A gas pipeline (6) is provided on the first pipeline (5); the outlet of the gas pipeline (6) is upward.
6. The ion-exchange membrane caustic soda hydrogen waste heat recovery device according to claim 5, characterized in that: A drying unit (7) is provided on the gas pipeline (6); a desiccant is provided in the drying unit (7).
7. The ion-exchange membrane caustic soda hydrogen waste heat recovery device according to claim 4, characterized in that: The liquid storage tank (4) and the refrigerator (2) are connected via a second pipeline (8); a liquid pump (10) is provided on the second pipeline (8); and a liquid outlet is provided at the bottom of the refrigerator (2).
8. The ion-exchange membrane caustic soda hydrogen waste heat recovery device according to claim 7, characterized in that: It also includes a controller and a temperature probe; the heat exchanger (1) and the refrigerator (2) are respectively provided with temperature probes; the controller is electrically connected to the temperature probe, the circulation pump (9) and the liquid pump (10).