Water-power-heat cogeneration device and control method

Abstract

A water-power-heat cogeneration device and a control method, relating to the technical field of fuel cells and comprehensive energy utilization. Waste heat of a fuel cell is used to desalinate seawater, and salinity gradient power between brine generated by seawater desalination and the seawater or fresh water can be directly used for power generation. The cogeneration device mainly consists of a fuel cell module, a thermal seawater desalination module, a salinity gradient power generation module, and a domestic hot water module. The waste heat of the fuel cell is used for power generation by automatic switching between two modes, i.e., generating power while producing the fresh water, and closed-loop salinity gradient power generation. The closed-loop mode eliminates the need for seawater pretreatment, thereby avoiding biofouling on the salinity gradient power generation module, improving power generation efficiency and comprehensive energy utilization efficiency, and reducing maintenance costs.

Description

Water-electricity-heat cogeneration device and control method TECHNICAL FIELD

[0001] The present application relates to a water-electricity-heat cogeneration device and control method, and belongs to the technical field of fuel cells and energy comprehensive utilization. BACKGROUND

[0002] Offshore platforms and offshore ships are far away from the mainland, and power supply and water supply are difficult problems. At present, power supply is mostly taken by "diesel generator + wind / light / wave + lithium battery", and water supply is mostly taken by membrane method or thermal method for seawater desalination. The above-mentioned scheme has the following problems: (1) environmental pollution, because renewable energy is unstable, a diesel generator is generally configured, and there is a risk of fuel leakage and exhaust pollution; (2) low comprehensive efficiency, the membrane method of seawater desalination needs to consume a lot of additional electric energy, and the thermal method of seawater desalination generally only utilizes a small part of diesel engine exhaust heat (the energy demand of offshore platforms or ships for electric power is much larger than the energy demand for fresh water, for example, for a hundred-meter-long fishing and traveling platform, the daily electric power demand is 100kW, and the daily fresh water demand is 20 tons, and the waste heat generated by the operation of the power generation equipment for 2 hours is enough to produce the required amount of fresh water), and it is urgent to develop a non-polluting and high-efficiency electric-water-heat cogeneration equipment.

[0003] SUMMARY

[0004] In order to solve the problem of diesel engine pollution in the existing power generation technology of offshore platforms and offshore ships, and the problem of low comprehensive efficiency of power supply and water supply, the present application provides a water-electricity-heat cogeneration device and control method, which uses a methanol fuel cell to reduce environmental pollution, and uses the waste heat of the methanol fuel cell to prepare fresh water, and can also utilize the salt difference energy between brine and fresh water generated by seawater desalination to directly generate electricity, when the fresh water meets the demand, the thermal method of seawater desalination does not stop working, and the prepared fresh water and brine are used to generate electricity in the salt difference power generation module, which greatly improves the energy comprehensive utilization efficiency.

[0005] The present application adopts the following technical scheme:

[0006] A water-electricity-heat cogeneration device, comprising: a fuel cell module, a thermal seawater desalination module, a salt difference power generation module and a domestic hot water module;

[0007] The fuel cell module comprises a stack and an exhaust heat exchanger;

[0008] The thermal seawater desalination module comprises a seawater desalination device, a first oil-water heat exchange device, a domestic fresh water tank, a fresh water tank, a brine tank and a first seawater pretreatment device;

[0009] The salt difference power generation module comprises a salt difference power generation device, a diluted brine tank and a first seawater pretreatment device;

[0010] The domestic hot water module comprises a domestic hot water tank and a second oil-water heat exchange device.

[0011] In the present application, the domestic hot water tank is connected with the domestic fresh water tank, and the water in the domestic hot water tank is supplied by the domestic fresh water tank.

[0012] The stack is heat exchange connected with the domestic hot water tank through the second oil-water heat exchange device, so as to transfer the stack waste heat to the water in the domestic hot water tank.

[0013] The tail gas exhaust channel of the stack is connected with the air inlet channel of the tail gas heat exchanger, so as to transfer the stack tail gas heat to the seawater desalination device.

[0014] The stack is heat exchange connected with the seawater desalination device through the first oil-water heat exchange device, so as to transfer the stack waste heat to the seawater desalination device.

[0015] One end of the seawater desalination device is provided with a to-be-desalinated water inlet, and the other end is provided with a fresh water outlet and a brine outlet.

[0016] The fresh water outlet is connected with the inlet of the domestic fresh water tank and the fresh water tank, and the brine outlet is connected with the inlet of the brine tank.

[0017] One end of the salt differential power generation device is provided with a first inlet and a second inlet, and the other end is provided with a diluted brine outlet.

[0018] The first inlet is connected with the outlet of the brine tank, and the second inlet is connected with the outlet of the fresh water tank and the outlet of the second seawater pretreatment device.

[0019] The inlet of the diluted brine tank is connected with the diluted brine outlet.

[0020] The to-be-desalinated water inlet on the seawater desalination device is connected with the outlet of the first seawater pretreatment device and the outlet of the diluted brine tank.

[0021] Optionally, the first oil-water heat exchange device and the second oil-water heat exchange device are heat exchange connected with the stack through an oil pipeline, so as to remove the heat of the stack through the circulation of the heat conducting oil in the oil pipeline.

[0022] A first three-way valve is arranged on the oil pipeline from the stack to the first oil-water heat exchange device and the second oil-water heat exchange device, so as to distribute the heat.

[0023] The first oil-water heat exchange device is heat exchange connected with the seawater desalination device through a water pipeline, and the heat exchange through the oil pipeline and the water pipeline is used to provide a heat source for seawater desalination.

[0024] The second oil-water heat exchange device is heat exchange connected with the circulating water pipeline of the domestic hot water tank, and the heat exchange through the oil pipeline and the circulating water pipeline is used to increase the water temperature in the domestic hot water tank.

[0025] Optionally, the inlet of the seawater to be desalinated on the seawater desalination device is communicated with the outlet of the first seawater pretreatment device and the outlet of the dilute brine tank through a pipeline provided with a second three-way valve.

[0026] The fresh water outlet is communicated with the inlet of the domestic fresh water tank and the fresh water tank through a pipeline provided with a third three-way valve.

[0027] Optionally, the inlet of the dilute brine tank and the dilute brine discharge port are communicated with the dilute brine outlet on the salt differential power generation device through a pipeline provided with a fourth three-way valve.

[0028] The second inlet on the salt differential power generation device is communicated with the outlet of the fresh water tank and the outlet of the second seawater pretreatment device through a pipeline provided with a fifth three-way valve.

[0029] Optionally, the salt differential power generation module is a pressure retarded osmosis (PRO) and / or reverse electrodialysis (RED) salt differential power generation device.

[0030] Optionally, the thermal seawater desalination module is a low-temperature multi-effect (MED) seawater desalination device and / or a multi-stage flash (MSF) seawater desalination device.

[0031] Optionally, the fuel cell module is a methanol fuel cell module. The type of fuel cell in the present application is not strictly limited, but can be preferably a methanol fuel cell.

[0032] The heat exchange connection in the present application refers to the connection between the devices, oil pipelines and water pipelines, but only the exchange of heat exists.

[0033] According to another aspect of the present application, a control method of the above-mentioned water-electricity-heat cogeneration device is provided. During the power generation process of the fuel cell module, the heat generated by the stack is transferred to the domestic hot water module through the second oil-water heat exchange device for heating the water in the domestic hot water tank; and / or, the heat is transferred to the thermal seawater desalination module through at least one of the first oil-water heat exchange device and the exhaust gas heat exchanger as a heat source of the seawater desalination device for water-electricity cogeneration.

[0034] The water-electricity cogeneration is:

[0035] The seawater is desalinated by the thermal seawater desalination module, and the desalinated water is discharged into the domestic fresh water storage tank, and the brine is discharged into the salt differential power generation module. The salt differential power generation module utilizes the brine and seawater to generate power and discharges dilute brine; or, the dilute brine generated by the salt differential power generation module is desalinated by the thermal seawater desalination module, and the desalinated water and brine are discharged. The desalinated water is discharged into the fresh water tank and the brine is discharged into the salt differential power generation module. The salt differential power generation module utilizes the fresh water and brine to generate power and discharges dilute brine.

[0036] In the present application, the heat of the fuel cell stack is passed through the oil-water heat exchanger, and the hot water / steam is used as the heat source to enter the seawater desalination device. The temperature of the seawater desalination device decreases, and the cooling water enters the oil-water heat exchanger. At the same time, the exhaust heat of the high-temperature exhaust gas of the fuel cell is recovered by the exhaust gas heat exchanger. The cooling water from the exhaust gas heat exchanger enters the seawater desalination device as a heat source, and the temperature of the seawater desalination device decreases, and the cooling water returns to the exhaust gas heat exchanger.

[0037] Optionally, the first three-way valve is adjusted so that sufficient heat-conducting oil in the oil pipeline enters the first oil-water heat exchanger to exchange heat with the water in the water pipeline, thereby providing a heat source for the seawater desalination device; and / or the heat of the stack tail is exchanged with the water in the water pipeline by the exhaust gas heat exchanger to provide a heat source for the seawater desalination device;

[0038] The amount of water in the domestic fresh water tank is monitored.

[0039] When the amount of water in the domestic fresh water tank does not reach the set value:

[0040] The second three-way valve is adjusted so that the seawater treated by the first seawater pretreatment device enters the seawater desalination device; the third three-way valve is adjusted so that the fresh water discharged from the seawater desalination device enters the domestic fresh water tank; the brine discharged from the seawater desalination device enters the salt differential power generation device, and the fifth three-way valve is adjusted so that the seawater treated by the second seawater pretreatment device enters the salt differential power generation device. The salt differential power generation device uses the brine and the seawater to generate power and discharges diluted brine, and the fourth three-way valve is adjusted so that the diluted brine is discharged.

[0041] When the amount of water in the domestic fresh water tank reaches the set value:

[0042] The second three-way valve is adjusted so that the diluted brine in the brine tank enters the seawater desalination device; the third three-way valve is adjusted so that the fresh water discharged from the seawater desalination device enters the fresh water tank; the brine discharged from the seawater desalination device enters the salt differential power generation device, and the fifth three-way valve is adjusted so that the fresh water in the fresh water tank enters the salt differential power generation device. The salt differential power generation device uses the brine and the fresh water to generate power and discharges diluted brine, and the fourth three-way valve is adjusted so that the diluted brine enters the diluted brine tank.

[0043] Optionally, the temperature of the water in the domestic hot water tank is monitored.

[0044] When the temperature of the water does not reach the set value, the first three-way valve is adjusted so that sufficient heat-conducting oil in the oil pipeline enters the second oil-water heat exchanger to exchange heat with the water in the circulating water pipeline of the domestic hot water tank to increase the temperature of the water.

[0045] When the temperature of the water reaches the set value, the first three-way valve is adjusted so that the heat-conducting oil in the oil pipeline stops entering the second oil-water heat exchanger.

[0046] Optionally, in the fuel cell module, the fuel cell is a high-temperature proton exchange membrane-based methanol fuel cell, and the type of the fuel cell is not strictly limited in the application, but can be preferably a high-temperature proton exchange membrane-based methanol fuel cell.

[0047] When the fuel cell is a high-temperature proton exchange membrane-based methanol fuel cell, the working temperature of the stack is 120-180℃, and oil cooling is used for heat dissipation.

[0048] The electricity-water-heat cogeneration device has an automatic control function, and can automatically adjust the utilization mode of the waste heat of the fuel cell according to the water temperature in the domestic hot water tank and the water amount in the domestic fresh water tank through the control of the three-way valves in the device.

[0049] The application can produce beneficial effects, including:

[0050] The water-electricity-heat cogeneration device and the control method provided by the application use a methanol fuel cell to reduce environmental pollution, and the methanol fuel cell has near-zero emissions of NO x , SO x , and PM, and the methanol is biodegradable and will not cause long-term environmental impact when leaked into open water, and the waste heat of the fuel cell can be fully utilized to ensure domestic hot water, prepare fresh water, and generate electricity at the same time, and the fuel has high comprehensive efficiency and no pollution. In the aspect of waste heat power generation, the power generation can be realized in two modes of preparing fresh water while generating electricity and through closed-cycle salt differential power generation. The closed-cycle salt differential power generation module avoids biological pollution and improves the power generation efficiency and reduces the maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a schematic diagram of the electricity-water-heat cogeneration device of the application.

[0052] Fig. 2 is a schematic diagram of the waste heat power generation mode 1 “seawater desalination + power generation mode” of the application.

[0053] Fig. 3 is a schematic diagram of the waste heat power generation mode 2 “pure power generation” of the application.

[0054] Fig. 4 is a schematic diagram of the waste heat utilization control method of the electricity-water-heat cogeneration device of the application.

[0055] Fig. 5 is a schematic diagram of the process of the electricity-water-heat cogeneration device of the application.

[0056] Figure 1: The flow chart of the water-electricity-heat cogeneration device. 101. The fuel cell stack; 102. The methanol fuel processor; 103. The methanol pump; 104. The methanol solution tank; 105. The exhaust gas heat exchanger; 106. The heat conducting oil pump; 107. The first three-way valve; 108. The first oil-water heat exchanger; 201. The seawater desalination device; 202. The circulating pump; 203. The first seawater pretreatment device; 204. The second three-way valve; 205. The brine tank; 206. The fresh water tank; 207. The third three-way valve; 301. The salt difference power generation device; 302. The dilute brine tank; 303. The second seawater pretreatment device; 304. The fourth three-way valve; 305. The fifth three-way valve; 401. The hot water storage tank; 402. The second oil-water heat exchanger; 501. The fresh water tank. DETAILED DESCRIPTION

[0057] The present application will be described in detail below with reference to the examples, but the present application is not limited to the examples.

[0058] The raw materials in the examples of the present application are commercially available unless otherwise specified.

[0059] The test methods are conventional unless otherwise specified, and the instrument settings are recommended by the manufacturers.

[0060] According to an embodiment of the present application, a water-electricity-heat cogeneration device, as shown in the flow chart of the electricity-water-heat cogeneration device, comprises a fuel cell module, a thermal seawater desalination module, a salt difference power generation module and a hot water module;

[0061] The fuel cell module comprises a fuel cell stack 101 and an exhaust gas heat exchanger 105.

[0062] The thermal seawater desalination module comprises a seawater desalination device 201, a first oil-water heat exchanger 108, a fresh water tank 501, a fresh water tank 206, a brine tank 205, a first seawater pretreatment device 204.

[0063] The salt difference power generation module comprises a salt difference power generation device 301, a dilute brine tank 302205, a first seawater pretreatment device 204.

[0064] The hot water module comprises a hot water tank 401 and a second oil-water heat exchanger 402.

[0065] The life hot water tank 401 is communicated with the life fresh water tank 501, and the water in the life hot water tank 401 is supplied by the life fresh water tank 501; the second oil-water heat exchange device 402 is connected in heat exchange with the life hot water tank 401 and the stack 101, so as to transfer the waste heat of the stack 101 to the water in the life hot water tank 401; the tail gas discharge channel of the stack 101 is communicated with the gas inlet channel of the tail gas heat exchanger 105, so as to transfer the heat of the tail gas of the stack 101 to the seawater desalination device 201; the first oil-water heat exchange device 108 is connected in heat exchange with the stack 101 and the seawater desalination device 201, so as to transfer the waste heat of the stack 101 to the seawater desalination device 201; one end of the seawater desalination device 201 is provided with a water inlet to be desalinated, and the other end is provided with a fresh water outlet and a brine outlet; the fresh water outlet is communicated with the inlet communicated with the life fresh water tank 501 and the fresh water tank 206, and the brine outlet is communicated with the inlet of the brine tank 205; one end of the salt differential power generation device 301 is provided with a first inlet and a second inlet, and the other end is provided with a diluted brine outlet; the first inlet is communicated with the outlet of the brine tank 205, and the second inlet is communicated with the outlet of the fresh water tank 206 and the outlet of the second seawater pretreatment device 303; the inlet of the diluted brine tank is communicated with the diluted brine outlet; the water inlet to be desalinated on the seawater desalination device 201 is communicated with the outlet of the first seawater pretreatment device 204 and the outlet of the diluted brine tank.

[0066] The first oil-water heat exchange device 108 and the second oil-water heat exchange device 402 are connected in heat exchange with the stack 101 through an oil pipeline, so as to remove the heat of the stack 101 through the circulation of the heat conducting oil in the oil pipeline; the first three-way valve 107 is arranged on the oil pipeline from the stack 101 to the first oil-water heat exchange device 108 and the second oil-water heat exchange device 402, so as to distribute the heat; the heat conducting oil pump 106 is arranged on the oil pipeline, so as to circulate the heat conducting oil in the oil pipeline. The first oil-water heat exchange device 108 is connected in heat exchange with the seawater desalination device 201 through a water pipeline, so as to provide a heat source for seawater desalination through the heat exchange of the oil pipeline and the water pipeline; the circulating pump 202 is arranged on the water pipeline, so as to circulate the water in the water pipeline. The second oil-water heat exchange device 402 is connected in heat exchange with the circulating water pipeline of the life hot water tank 401, so as to increase the water temperature in the life hot water tank 401 through the heat exchange of the oil pipeline and the circulating water pipeline. The water inlet to be desalinated on the seawater desalination device 201 is communicated with the outlet of the first seawater pretreatment device 204 and the outlet of the diluted brine tank through the pipeline provided with the second three-way valve 204; the fresh water outlet is communicated with the inlet communicated with the life fresh water tank 501 and the fresh water tank 206 through the pipeline provided with the third three-way valve 207. Optionally, the inlet of the diluted brine tank and the diluted brine discharge port are communicated with the diluted brine outlet on the salt differential power generation device 301 through the pipeline provided with the fourth three-way valve 304; the second inlet on the salt differential power generation device 301 is communicated with the outlet of the fresh water tank 206 and the outlet of the second seawater pretreatment device 303 through the pipeline provided with the fifth three-way valve 305.

[0067] The salt differential power module is a pressure delayed osmosis technology (PRO) and / or reverse electrodialysis technology (RED) salt differential power device 301. The thermal method seawater desalination module is a low-temperature multi-effect (MED) seawater desalination device 201 and / or a multi-stage flash (MSF) seawater desalination device 201. The fuel cell module is a methanol fuel cell module.

[0068] Exemplarily, the principle schematic diagram of the electricity-water-heat cogeneration device of the present application is shown in FIG. 1, the fuel cell module is taken as a methanol fuel cell module (i.e. the methanol fuel cell comprehensive energy system shown in FIG. 1), the thermal method seawater desalination module is taken as low-temperature distillation for fresh water, and the principle of the electricity-water-heat cogeneration device of the present application is that the waste heat generated by the methanol fuel cell module is transferred to the thermal method seawater desalination module by external circulation (heat is transferred by heat transfer oil) to utilize heat exchange to transfer the waste heat to the thermal method seawater desalination module as a heat source required for low-temperature distillation for fresh water, and the waste heat is also transferred to the domestic hot water module by heat exchange to heat the water temperature. The low-temperature distillation for fresh water process processes seawater into fresh water and brine, and the brine flows into the salt differential power module to generate power by utilizing the salt difference between the brine and seawater.

[0069] Embodiment 1 electricity-water-heat cogeneration device and control method thereof

[0070] The process schematic diagram of the electricity-water-heat cogeneration device is shown in FIG. 5, 60%vol methanol solution in the methanol tank 104 enters the methanol fuel processor 102 to generate steam reforming response, generates hydrogen-rich fuel gas to enter the electric pile 101 (high-temperature proton exchange membrane fuel cell electric pile) to generate power, and the excess hydrogen tail gas returns to enter the methanol fuel processor 102 to burn, providing the required heat for steam reforming. The heat generated by the fuel cell electric pile 101 is removed by heat transfer oil, the heat transfer oil is pumped into the first oil-water heat exchanger 108 or the second oil-water heat exchanger 402 by the heat transfer oil pump 106 and the first three-way valve 107, wherein the heat transfer oil pumped into the second oil-water heat exchanger 402 exchanges heat with the water in the domestic hot water tank 401 (the water in the domestic hot water tank 401 is supplied by the domestic fresh water tank 501), to improve the temperature of the domestic hot water, and the cathode air tail gas of the electric pile 101 is discharged after water heat exchange by the tail gas heat exchanger 105, and the heat-exchanged hot water is also used as a heat source for the seawater desalination device.

[0071] The heat-conducting oil pumped into the first oil-water heat exchanger 108 exchanges heat with the water circulating in the seawater desalination device through the circulating pump 202. The heated water / steam after heat exchange serves as a heat source and is provided to the low-temperature multi-effect (MED) distillation seawater desalination device 201. The seawater pretreated by the first seawater pretreatment device 203 or the diluted brine in the diluted brine tank 302 enters the low-temperature multi-effect (MED) distillation seawater desalination device 201 through the second three-way valve 204, is desalinated using the aforementioned heat source, and brine and fresh water are discharged. The low-temperature multi-effect (MED) distillation seawater desalination device 201. Among them, the fresh water enters the domestic fresh water tank 501 for storage or enters the fresh water tank 206 through the third three-way valve 207, and the brine enters the brine tank 205; the fresh water in the fresh water tank 206 or the seawater treated by the second seawater pretreatment device 303 enters the salinity power generation device 301 (in this embodiment, the salinity power generation device 301 is specifically a reverse electrodialysis device 301) through the fifth three-way valve 305, and forms a salinity difference with the brine entering the reverse electrodialysis device 301 from the brine tank 205 to generate salinity power. The diluted brine discharged from the reverse electrodialysis device 301 is discharged or enters the diluted brine tank 302 through the fourth three-way valve 304.

[0072] The control method for waste heat utilization of the combined power and water and heat generation device is shown in FIG. 4. When the system of the combined power and water and heat generation device is running, whether the water quantity in the domestic hot water storage tank 401 meets the set value is monitored (the water in the domestic hot water tank 401 is supplied by the domestic fresh water tank 501):

[0073] When the fresh water quantity is insufficient, the waste heat power generation mode 1 "seawater desalination + power generation mode" is entered. This mode is shown in FIG. 2. The seawater is desalinated using the waste heat of the methanol fuel cell, and the produced fresh water is used for replenishment, and the produced brine is used for salinity power generation with seawater. The specific operation is as follows: adjust the second three-way valve 204, and the seawater enters the low-temperature multi-effect distillation seawater desalination device 201 after pretreatment; adjust the third three-way valve 207, and the generated fresh water enters the domestic fresh water storage tank 501, and the generated brine enters the brine tank 206 and finally enters the reverse electrodialysis device 301. At the same time, adjust the fifth three-way valve 305, and the seawater enters the reverse electrodialysis device 301 after pretreatment, and the salinity power generation is performed using the brine and seawater. Adjust the fourth three-way valve 304 to discharge the solution after mixing the seawater and brine.

[0074] When the amount of fresh water meets the requirements, enter the waste heat power generation mode 2 "simple power generation", the mode is shown in Figure 3, using the methanol fuel cell waste heat to carry out seawater desalination on the diluted brine produced by the salt difference power generation, and after producing fresh water and brine, continue to carry out salt difference power generation, the specific operation is: adjust the second three-way valve 204, so that the diluted brine in the diluted brine tank 302 enters the low-temperature multi-effect distillation seawater desalination device 201, adjust the third three-way valve 207, so that the generated fresh water enters the fresh water tank 206, and adjust the fifth three-way valve 305, so that the fresh water enters the reverse electrodialysis device 301, and the generated brine enters the brine tank 206 and finally enters the reverse electrodialysis device 301, and use the fresh water and brine to generate power. Adjust the fourth three-way valve 304, so that the fresh water and brine mixed solution enters the diluted brine tank 302. In order to make the reverse electrodialysis more efficient, NaCl, a supporting electrolyte, can be added to the fresh water entering the reverse electrodialysis device 301.

[0075] When the system is running, monitor whether the temperature in the domestic hot water tank 401 meets the set value, when the temperature does not reach the set value, adjust the first three-way valve 107, so that part of the heat transfer oil enters the second oil-water heat exchanger 402 and exchanges heat with the water. When the temperature reaches the set value, adjust the first three-way valve 107, so that no heat transfer oil flows through the second oil-water heat exchanger 402.

[0076] The utilization of the waste heat of the methanol fuel cell includes: 1. providing domestic hot water, 2. providing a heat source for the seawater desalination module, 3. indirectly used for salt difference power generation, the present embodiment can automatically switch between the two aforementioned waste heat power generation modes, and the core processes of the two modes are as follows:

[0077] Mode 1: produce fresh water + generate power, seawater enters the seawater desalination device, the waste heat of the fuel cell is used for seawater desalination, and the brine and seawater after seawater desalination enter the salt difference power generation module to generate power;

[0078] Mode 2: simple power generation, the mixed solution (diluted brine) after salt difference power generation enters the seawater desalination device, the waste heat of the fuel cell is used for seawater desalination, and the brine and fresh water after seawater desalination enter the salt difference power generation module to generate power, at this time, the salt difference power generation and seawater desalination form a closed cycle.

[0079] The above is only a few embodiments of the present application, and does not limit the present application in any form, although the preferred embodiments are disclosed as above, however, it is not intended to limit the present application, any person skilled in the art, within the scope of the technical solution of the present application, makes some changes or modifications using the above disclosed technical content, which is equivalent to the equivalent embodiment, and belongs to the scope of the technical solution.

Claims

1. A water-electric-heat cogeneration device, characterized by, The application relates to a fuel cell module, a thermal seawater desalination module, a salt differential power generation module and a domestic hot water module. The fuel cell module comprises a stack and a tail gas heat exchanger. The thermal seawater desalination module comprises a seawater desalination device, a first oil-water heat exchange device, a domestic fresh water tank, a fresh water tank, a brine tank and a first seawater pretreatment device. The salt differential power generation module comprises a salt differential power generation device, a dilute brine tank and a first seawater pretreatment device. The domestic hot water module comprises a domestic hot water tank and a second oil-water heat exchange device. The stack and the domestic hot water tank are connected through the second oil-water heat exchange device to transfer the stack waste heat to the water in the domestic hot water tank. The tail gas discharge channel of the stack is communicated with the air inlet channel of the tail gas heat exchanger to transfer the stack tail gas heat to the seawater desalination device. The stack and the seawater desalination device are connected through the first oil-water heat exchange device to transfer the stack waste heat to the seawater desalination device. One end of the seawater desalination device is provided with a water inlet to be desalinated, and the other end is provided with a fresh water outlet and a brine outlet. The fresh water outlet is communicated with the inlet of the domestic fresh water tank and the fresh water tank, and the brine outlet is communicated with the inlet of the brine tank. One end of the salt differential power generation device is provided with a first inlet and a second inlet, and the other end is provided with a dilute brine outlet. The first inlet is communicated with the outlet of the brine tank, and the second inlet is communicated with the outlet of the fresh water tank and the outlet of the second seawater pretreatment device. The inlet of the dilute brine tank is communicated with the dilute brine outlet. The water inlet to be desalinated on the seawater desalination device is communicated with the outlet of the first seawater pretreatment device and the outlet of the dilute brine tank. The first oil-water heat exchange device and the second oil-water heat exchange device are connected with the stack through oil pipelines.

2. The water-electric-heat co-generation apparatus according to claim 1, characterized by A first three-way valve is arranged on the oil pipeline from the stack to the first oil-water heat exchange device and the second oil-water heat exchange device. The first oil-water heat exchange device is connected with the seawater desalination device through a water pipeline. The second oil-water heat exchange device is connected with the circulating water pipeline of the domestic hot water tank. The water inlet to be desalinated on the seawater desalination device is communicated with the outlet of the first seawater pretreatment device and the outlet of the dilute brine tank through a pipeline provided with a second three-way valve.

3. The water-electric-heat cogeneration device according to claim 1 or 2, characterized by, The fresh water outlet is communicated with the inlet of the domestic fresh water tank and the fresh water tank through a pipeline provided with a third three-way valve. The inlet of the dilute brine tank and the dilute brine discharge port are communicated with the dilute brine outlet on the salt differential power generation device through a pipeline provided with a fourth three-way valve.

4. The water-electric-heat cogeneration device according to any one of claims 1 to 3, characterized by The second inlet on the salt differential power generation device is communicated with the outlet of the fresh water tank and the outlet of the second seawater pretreatment device through a pipeline provided with a fifth three-way valve. The salt differential power generation module is a salt differential power generation device adopting pressure delayed osmosis technology and / or reverse electrodialysis technology.

5. The water-electric-heat cogeneration device according to any one of claims 1 to 4, characterized by The fuel cell module is a methanol fuel cell module.

6. The water-electric-heat cogeneration device according to any one of claims 1 to 5, characterized by During the power generation of the fuel cell module, the heat generated by the stack is transferred to the domestic hot water module through the second oil-water heat exchange device to heat the water in the domestic hot water tank; and / or the heat is transferred to the thermal seawater desalination module through at least one of the first oil-water heat exchange device and the tail gas heat exchanger to serve as the heat source of the seawater desalination device to realize water-electricity cogeneration.

7. The method of controlling a water-electric-heat cogeneration apparatus according to any one of claims 1 to 6, characterized by, The water-electricity cogeneration is ​ The seawater is desalinated by the thermal seawater desalination module, and the desalinated water is discharged into a domestic fresh water tank, and the brine is discharged into a salt differential power generation module, which utilizes the brine and seawater to generate salt differential power and discharges diluted brine; or, the diluted brine generated by the salt differential power generation module is desalinated by the thermal seawater desalination module, and the desalinated water and brine are discharged, and the desalinated water is discharged into the fresh water tank and then discharged into the salt differential power generation module together with the brine, and the salt differential power generation module utilizes the fresh water and brine to generate salt differential power and discharges diluted brine.

8. The control method according to claim 7, characterized by, The first three-way valve is adjusted so that sufficient heat conducting oil in the oil pipeline enters the first oil-water heat exchanger to exchange heat with water in the water pipeline, thereby providing a heat source for the seawater desalination device; and / or the heat of the tail gas of the electric pile is exchanged with water in the water pipeline through the tail gas heat exchanger, thereby providing a heat source for the seawater desalination device; The water quantity in the domestic fresh water tank is monitored. When the water quantity in the domestic fresh water tank does not reach a set value: The second three-way valve is adjusted so that the seawater treated by the first seawater pretreatment device enters the seawater desalination device; and the third three-way valve is adjusted so that the desalinated water discharged by the seawater desalination device enters the domestic fresh water tank; The brine discharged by the seawater desalination device enters the salt differential power generation device, and the fifth three-way valve is adjusted so that the seawater treated by the second seawater pretreatment device enters the salt differential power generation device, the salt differential power generation device utilizes the brine and seawater to generate salt differential power and discharges diluted brine, and the fourth three-way valve is adjusted so that the diluted brine is discharged. When the water quantity in the domestic fresh water tank reaches the set value: The second three-way valve is adjusted so that the diluted brine in the brine tank enters the seawater desalination device; the third three-way valve is adjusted so that the desalinated water discharged by the seawater desalination device enters the fresh water tank; the brine discharged by the seawater desalination device enters the salt differential power generation device, and the fifth three-way valve is adjusted so that the fresh water in the fresh water tank enters the salt differential power generation device, the salt differential power generation device utilizes the brine and fresh water to generate salt differential power and discharges diluted brine, and the fourth three-way valve is adjusted so that the diluted brine enters the diluted brine tank.

9. The control method according to claim 7 or 8, characterized by, The water temperature in the domestic hot water tank is monitored. When the water temperature does not reach the set value, the first three-way valve is adjusted so that sufficient heat conducting oil in the oil pipeline enters the second oil-water heat exchanger to exchange heat with water in the circulating water pipeline of the domestic hot water tank to increase the water temperature. When the water temperature reaches the set value, the first three-way valve is adjusted so that the heat conducting oil in the oil pipeline stops entering the second oil-water heat exchanger.

10. The control method according to any one of claims 7 to 9, characterized in that, In the fuel cell module, the fuel cell is a high-temperature proton exchange membrane-based methanol fuel cell.

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