Recycling system for assisting seawater distillation and desalination by using radiation waste heat of water electrolyser
By installing heat pipes and thermal energy storage units on the outer wall of the water electrolyzer, the radiant waste heat is used to provide thermal energy for the seawater desalination device, which solves the problem of unutilized waste heat in the water electrolyzer, improves energy utilization and reduces hydrogen production costs.
Patent Information
- Application Number
- CN202422677135.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-10-10
- Estimated Expiration
- 2034-11-04
AI Technical Summary
In the seawater desalination process of existing offshore hydrogen production platforms, the radiant waste heat generated by the water electrolyzer is not effectively utilized, resulting in low energy utilization and increased hydrogen production costs.
A recovery system for seawater distillation and desalination is designed, which utilizes the radiant waste heat of a water electrolyzer to assist in desalination. Heat from the outer wall of the water electrolyzer is transferred to thermal oil via a heat pipe. Heat exchange between the thermal oil and seawater is then performed to provide preheating heat energy for the desalination device. Thermal energy management is optimized through a thermal energy storage unit and an intelligent control module.
It improves the overall energy utilization efficiency of the water electrolyzer, reduces the energy consumption and operating costs of seawater desalination, and ensures that the system can still operate stably when thermal energy is unstable, which has important economic benefits.
Smart Images
Figure CN223422428U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of seawater desalination, in particular to a recovery system that utilizes the radiant waste heat of a water electrolyzer to assist in the distillation and desalination of seawater. Background Art
[0002] Existing technologies for offshore wind power hydrogen production can be broadly categorized into offshore wind power + onshore hydrogen production, distributed offshore hydrogen production + pipeline hydrogen transportation, and centralized offshore hydrogen production + pipeline hydrogen transportation. Both distributed and centralized offshore hydrogen production methods utilize offshore hydrogen production, with equipment typically concentrated on hydrogen production platforms independent of the sea surface. Freshwater production often requires independent desalination equipment on these platforms. Ensuring a stable freshwater supply and reducing production costs are currently key research areas for offshore hydrogen production platforms.
[0003] Currently, the most commonly used desalination technologies on offshore hydrogen production platforms are low-temperature multi-effect distillation and multi-stage flash evaporation, both of which are part of the multi-effect distillation process. Seawater reverse osmosis is also an alternative. The purified water produced by distillation is typically used as feed water for the electrolyzers and for employee living. For equipment using distillation for desalination, the seawater must be preheated to 50°C-80°C before entering the distiller, typically using an electric heater. The electrolyzer generates a significant amount of byproduct heat during hydrogen production, with electrolysis efficiency typically ranging from 60% to 70%. This means that for every kWh of electricity consumed, approximately 0.3-0.4 kWh is converted into heat. This byproduct heat is primarily discharged in two forms: hot water discharged through the cooling system, which can be recycled and accounts for approximately 50% of the heat energy; and nearly half of the heat energy is released into the surrounding environment as radiation, remaining largely unused. This results in low energy efficiency and a waste of resources.
[0004] Therefore, how to design a recovery system that can utilize the radiant waste heat of the water electrolyzer to assist in seawater distillation and desalination, and improve the energy utilization and economy of the wind power hydrogen production process, has become a technical problem that technical personnel in this field urgently need to solve. Utility Model Content
[0005] In view of the above-mentioned defects of the prior art, the utility model provides a recovery system that utilizes the radiant waste heat of the water electrolyzer to assist in the distillation and desalination of seawater, the purpose of which is to recycle the hydrogen production energy and reduce the electricity consumption in the seawater desalination process.
[0006] To achieve the above technical objectives, the present invention provides a recovery system for utilizing the radiant waste heat of a water electrolyzer to assist in the distillation and desalination of seawater, comprising a water electrolyzer, wherein a heat pipe is provided on the outer wall of the water electrolyzer, wherein the heat pipe is connected to a thermal energy storage unit via a pipeline, wherein the thermal energy storage unit is connected to a hot fluid inlet of a heat exchanger via a pipeline, and an oil pump and an oil storage tank are provided on one side of the water electrolyzer, wherein the oil pump is connected to the heat pipe and the oil storage tank respectively via pipelines, and wherein the oil storage tank is connected to a cold fluid outlet of the heat exchanger via a pipeline;
[0007] The heat exchanger further comprises a cold fluid inlet for inputting low-temperature seawater, and a hot fluid outlet for outputting preheated seawater, and the hot fluid outlet of the heat exchanger is connected to the seawater desalination device through a pipeline;
[0008] Temperature control sensors are respectively provided at the connection points of the heat pipe, the thermal energy storage unit and the heat exchanger. A first valve and a second valve are respectively provided on the connecting pipe between the heat pipe and the thermal energy storage unit, and on the connecting pipe between the thermal energy storage unit and the heat exchanger. A thermal energy management module is provided at the pipe connection between the thermal energy storage unit and the heat exchanger. The thermal energy management module is used to receive temperature data from each temperature control sensor and automatically adjust the first valve and the second valve.
[0009] Preferably, the heat conducting pipes are installed in the form of coil structures in the areas of the positive electrode and the negative electrode where the outer wall of the water electrolysis cell generates the most heat.
[0010] Preferably, thermal conductive glue is applied between the heat-conducting pipe and the electrolytic cell, and the outer layer of the heat-conducting pipe is provided with thermal insulation material.
[0011] Preferably, the thermal energy storage unit is a phase change heat storage device.
[0012] Preferably, an auxiliary electric heater is provided on the connecting pipe between the heat exchanger and the seawater desalination device.
[0013] Beneficial effects of the utility model:
[0014] Due to the above-mentioned structural design, the utility model effectively utilizes the radiation waste heat resources generated by the outer wall of the water electrolyzer during operation, and exchanges heat with seawater through the heat-conducting oil of the heat-conducting pipe on the outer wall of the water electrolyzer, thereby finding an alternative source of heat for preheating seawater in the seawater desalination device, improving the overall energy utilization efficiency of the water electrolyzer, and reducing the energy consumption and operating costs of the system; at the same time, it is equipped with a thermal energy storage unit as a supplement to ensure that it can still operate stably and efficiently when the by-product heat energy is insufficient; the intelligent control of the thermal energy management module further improves the stability and efficiency of the system, and has important economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a system schematic diagram of the present utility model.
[0016] In the figure: 1 water electrolyzer, 2 heat pipe, 3 thermal energy storage unit, 4 heat exchanger, 5 oil pump, 6 oil storage tank, 7 thermal energy management module, 8 first valve, 9 second valve, 10 auxiliary electric heater. DETAILED DESCRIPTION
[0017] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.
[0018] Example:
[0019] like Figure 1 As shown, a recovery system for assisting seawater distillation and desalination using radiant waste heat from a water electrolyzer comprises a water electrolyzer 1, an outer wall of which is provided with a heat pipe 2, which is connected to a thermal energy storage unit 3 via a pipeline, and the thermal energy storage unit 3 is connected to a hot fluid inlet of a heat exchanger 4 via a pipeline. An oil pump 5 and an oil storage tank 6 are provided on one side of the water electrolyzer 1, and the oil pump 5 is connected to the heat pipe 2 and the oil storage tank 6 respectively via pipelines, and the oil storage tank 6 is connected to a cold fluid outlet of the heat exchanger 4 via a pipeline.
[0020] The heat exchanger 4 further includes a cold fluid inlet for inputting low-temperature seawater, and a hot fluid outlet for outputting preheated seawater. The hot fluid outlet of the heat exchanger 4 is connected to the seawater desalination device through a pipeline;
[0021] Temperature control sensors are respectively provided at the connection points of the heat pipe 2, the thermal energy storage unit 3 and the heat exchanger 4. A first valve 8 and a second valve 9 are respectively provided on the connecting pipe between the heat pipe 2 and the thermal energy storage unit 3, and on the connecting pipe between the thermal energy storage unit 3 and the heat exchanger 4. A thermal energy management module 7 is provided at the pipe connection between the thermal energy storage unit 3 and the heat exchanger 4. The thermal energy management module 7 is used to receive temperature data from each temperature control sensor and automatically adjust the first valve 8 and the second valve 9.
[0022] The main innovation of the present invention is that it effectively utilizes the radiation waste heat resources generated by the outer wall of the water electrolysis cell 1 during operation, thereby improving the overall energy utilization efficiency of the water electrolysis cell 1 and reducing the energy consumption and operation cost of the system.
[0023] Specifically, the heat pipe 2 is installed in the area of the positive electrode and the negative electrode on the outer wall of the water electrolyzer 1 where the most heat is generated. The heat pipe 2 is close to the outer wall of the water electrolyzer 1, and uses synthetic heat-conducting oil (such as polyisobutylene, polyether oil) to quickly conduct the heat generated by the water electrolyzer 1 to the heat exchanger 4 and the thermal energy storage unit 3; in order to increase the heat conduction efficiency between the heat pipe 2 and the outer wall of the water electrolyzer 1, a thermal adhesive is applied between the heat pipe 2 and the outer wall of the water electrolyzer 1. The material of the heat pipe 2 is a high thermal conductivity metal, such as copper or aluminum, to ensure efficient heat transfer; the heat pipe 2 has a diameter of 20mm, and the outer layer of the heat pipe 2 uses insulation material to reduce heat loss. The heat pipe 2 is installed in a coil manner and is coiled into 3-5 turns along the outer wall of the water electrolyzer 1 at the electrode to ensure that the flow rate of the heat-conducting oil in the pipe is maintained at 1-3m / s to maintain good heat conduction and flow.
[0024] Thermal energy storage unit 3 is a phase-change heat storage device. Its function is to provide a stable heat source when heat supply is unstable or demand fluctuates, balancing heat supply and demand and increasing the flexibility of heat supply. This unit is located between heat exchanger 4 and water electrolyzer 1 and is connected to heat exchanger 4 via a pipeline. When water electrolyzer 1 generates sufficient heat, the thermal oil is preferentially transferred to heat exchanger 4 to heat the seawater. Meanwhile, the remaining heat is stored in thermal energy storage unit 3 via a pipeline. Conversely, when water electrolyzer 1 is insufficiently heated or the distillation unit is under heavy load, thermal energy storage unit 3 releases the stored thermal oil, which flows through the same pipeline into heat exchanger 4 to continue providing heat energy for the desalination unit.
[0025] Furthermore, the thermal energy storage unit 3 uses phase change material (PCM) as a medium to store and release thermal energy; its advantages are high heat storage density, the ability to store a large amount of heat in a relatively small volume, and the ability to maintain a constant temperature for heat release. Phase change materials are very suitable for occasions requiring efficient thermal energy storage.
[0026] Heat exchanger 4 is a plate-type heat exchanger installed in close proximity to the electrode area of water electrolyzer 1. Heat pipe 2 is connected to the hot fluid inlet of heat exchanger 4, directing the heat energy transferred from water electrolyzer 1 to heat exchanger 4. Heat transfer oil and seawater exchange heat in heat exchanger 4. The heat transfer oil passes through heat exchanger 4, transferring heat to the seawater while simultaneously cooling the oil. It then flows out of the cold fluid outlet and returns to oil storage tank 6 for recirculation. Temperature control sensors are installed at the high-temperature heat transfer oil inlet and preheated seawater outlet connections of heat exchanger 4 to monitor heat exchange efficiency and temperature status.
[0027] The oil pump 5 is used to promote the circulation of the heat transfer oil in the system. The oil pump 5 is placed next to the water electrolyzer 1. After the oil pump 5 sucks the heat transfer oil from the oil storage tank 6, it is transported to the coils of the positive and negative electrodes of the water electrolyzer 1 through the heat pipe 2. The heated heat transfer oil is collected and then transported to the heat exchanger 4 for heat exchange with seawater. The cooled heat transfer oil is returned to the oil storage tank 6 from the heat exchanger 4 to complete the cycle.
[0028] The thermal energy management module 7 is responsible for coordinating the temperature control sensors and automatically controlling the adjustment operations of the first valve 8 and the second valve 9. The logic controller of the thermal energy management module 7 automatically adjusts the first valve 8 and the second valve 9 according to the real-time detected temperature data to determine the flow direction of thermal energy; the logic controller can intelligently determine when to store heat in the thermal energy storage unit 3 and when to release heat from the thermal energy storage unit 3, ensuring that the entire system maintains thermal energy balance and efficient operation under various working conditions.
[0029] In some embodiments, an auxiliary electric heater 10 is provided on the connecting pipe between the heat exchanger 4 and the seawater desalination device. If the waste heat is not sufficient to fully meet the heat demand of the heating zone, the auxiliary electric heater 10 can be automatically started to provide additional heat to supplement the shortfall and heat the seawater to the temperature required for preheating; the connection design between the auxiliary electric heater 10 and the heat pipe 2 enables it to intervene in time when the waste heat is insufficient to ensure the temperature stability of the heating zone.
[0030] In summary, the most commonly used water electrolysis hydrogen production devices are alkaline water electrolysis devices and PEM proton exchange membrane water electrolysis devices. The utility model can be applied to both types of water electrolyzers; the utility model effectively utilizes the radiation waste heat resources generated by the outer wall of the water electrolyzer 1 during operation, and exchanges heat with seawater through the heat-conducting oil of the heat-conducting pipe 2 on the outer wall of the water electrolyzer 1, thereby finding an alternative source of seawater preheating heat for the seawater desalination device (distillation device), improving the overall energy utilization efficiency of the water electrolyzer 1, and reducing the energy consumption and operating cost of the distillation system; at the same time, it is equipped with a thermal energy storage unit 3 as a supplement to ensure stable and efficient operation when the by-product heat energy is insufficient; the intelligent control of the thermal energy management module 7 further improves the stability and efficiency of the system, and has important economic benefits.
[0031] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection defined by the claims.
Claims
1. A recovery system for seawater distillation and desalination utilizing radiant waste heat from a water electrolyzer, comprising a water electrolyzer, characterized in that: A heat pipe is provided on the outer wall of the water electrolyzer, and the heat pipe is connected to a thermal energy storage unit through a pipeline. The thermal energy storage unit is connected to a hot fluid inlet of a heat exchanger through a pipeline. An oil pump and an oil storage tank are provided on one side of the water electrolyzer, and the oil pump is connected to the heat pipe and the oil storage tank respectively through pipelines. The oil storage tank is connected to a cold fluid outlet of the heat exchanger through a pipeline. The heat exchanger further comprises a cold fluid inlet for inputting low-temperature seawater, and a hot fluid outlet for outputting preheated seawater, and the hot fluid outlet of the heat exchanger is connected to the seawater desalination device through a pipeline; Temperature control sensors are respectively provided at the connection points of the heat pipe, the thermal energy storage unit and the heat exchanger. A first valve and a second valve are respectively provided on the connecting pipe between the heat pipe and the thermal energy storage unit, and on the connecting pipe between the thermal energy storage unit and the heat exchanger. A thermal energy management module is provided at the pipe connection between the thermal energy storage unit and the heat exchanger. The thermal energy management module is used to receive temperature data from each temperature control sensor and automatically adjust the first valve and the second valve.
2. The recovery system for utilizing the radiant waste heat of a water electrolyzer to assist in seawater distillation and desalination according to claim 1, characterized in that: The heat conducting pipes are respectively installed in the form of coil structures in the positive electrode and negative electrode areas where the heat is generated the most on the outer wall of the water electrolysis tank.
3. The recovery system for utilizing the radiant waste heat of a water electrolyzer to assist in seawater distillation and desalination according to claim 1 or 2, characterized in that: Thermal conductive glue is applied between the heat conducting pipe and the electrolytic cell, and the outer layer of the heat conducting pipe is provided with thermal insulation material.
4. The recovery system for utilizing the radiant waste heat of a water electrolyzer to assist in seawater distillation and desalination according to claim 3, characterized in that: The thermal energy storage unit is a phase change heat storage device.
5. The recovery system for utilizing the radiant waste heat of a water electrolyzer to assist in seawater distillation and desalination according to claim 4, characterized in that: An auxiliary electric heater is provided on the connecting pipe between the heat exchanger and the seawater desalination device.