CN115751767A - Multi-system coupled combined heat, power and water supply system and method - Google Patents

Abstract

The invention discloses a multi-system coupled heat, power and water combined supply system and method, including a solar system, a water electrolyzer system, a fuel cell system, a heat pump system and a membrane distillation system; the solar system and the fuel cell system provide electric energy for users and heat energy; the water electrolyzer system utilizes the electric energy provided by the solar system to produce hydrogen and provides it to the fuel cell system; the feed liquid treatment water of the membrane distillation system utilizes the heat of the solar system and the fuel cell system to produce drinkable fresh water; The heat pump system is coupled with the membrane distillation system through a condenser and an evaporator; the present invention is based on the principle of cascade utilization of energy, and integrates a solar energy system, a water electrolyzer, a fuel cell system, a heat pump system and a membrane distillation system, and has better The temperature matching effect can realize the purpose of providing electric energy, drinking fresh water, domestic hot water and energy storage.

Description

A multi-system coupled heat, power and water cogeneration system and method

technical field

The invention relates to the technical field of renewable energy utilization and energy systems, in particular to a multi-system coupled heat, power and water combined supply system and method.

Background technique

Renewable energy such as solar energy has problems such as intermittency and discontinuity, and a suitable energy carrier is needed to provide users with continuous and reliable energy. As one of the alternative energy sources of traditional fossil energy, hydrogen energy has attracted much attention, and the technology of coupling photovoltaic power generation and electrolysis of water to produce hydrogen can achieve the goal of energy saving and emission reduction.

The traditional energy system mainly satisfies people's demand for electricity, cooling and heating by dividing production, and its energy utilization efficiency is low, resulting in waste of resources and serious environmental pollution. Distributed cogeneration system is an efficient, reliable and environmentally friendly energy system, and it is an important development direction in the field of comprehensive energy utilization technology.

With the increasing scarcity and increasing demand of fresh water resources, fresh water production technology has been developed unprecedentedly. Low-grade heat-driven membrane distillation water treatment technology is considered to be an effective water purification method, which can be widely used in the desalination of seawater and brackish water, especially in the treatment of high-concentration brine. The inventors found that the existing cogeneration systems usually couple the two systems to supply one or two types of energy, which cannot meet people's needs for multiple energies at the same time. Therefore, it is urgent to study a thermoelectric system that can realize thermoelectric Multi-energy cogeneration system for water co-supply.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a multi-system coupled heat, power and water cogeneration system and method, which integrates solar photovoltaic/photothermal, proton exchange membrane water electrolyzer, fuel cell, heat pump and membrane distillation, Improve the comprehensive utilization efficiency of energy.

Technical scheme of the present invention is as follows:

In the first aspect of the present invention, a multi-system coupled heat, power and water cogeneration system is provided, including a solar energy system, a water electrolyzer system, a fuel cell system, a heat pump system and a membrane distillation system;

The solar system and the fuel cell system provide users with electric energy and heat energy; the water electrolyzer system utilizes the electric energy provided by the solar system to produce hydrogen and provides it to the fuel cell system; the feed liquid treatment water of the membrane distillation system utilizes the solar system and the heat of the fuel cell system to produce drinkable fresh water; the heat pump system is coupled with a membrane distillation system through a condenser and an evaporator.

In some embodiments of the present invention, the solar energy system includes a solar photovoltaic photothermal integrated assembly, wherein the photovoltaic assembly is connected to a DC controller, and the photothermal assembly is sequentially connected to a water pump hot water storage tank.

In some embodiments of the present invention, one of the DC controllers is connected to a DC/AC converter to provide electric energy for users, and the other is connected to a DC/DC converter to provide electric energy for the water electrolyzer system.

In some embodiments of the present invention, the water electrolyzer system includes a PEM water electrolyzer, and the hydrogen gas outlet of the PEM water electrolyzer is connected to a hydrogen storage bottle.

In some embodiments of the present invention, the fuel cell system includes a PEMFC stack, the hydrogen inlet of the PEMFC stack is connected to the hydrogen storage bottle, the oxygen inlet is connected to the air compressor, and the anode and cathode of the PEMFC stack are The wet gas outlets are all provided with gas-liquid separators, and the liquid outlets of the gas-liquid separators are connected with the water storage tank.

In some embodiments of the present invention, the membrane distillation system includes a membrane distillation assembly, a feed liquid tank and a permeate tank, and the feed liquid outlet of the feed liquid tank passes through the heat exchanger of the fuel cell system, the heat storage of the solar system The water tank and the condenser of the heat pump system are connected with the high-temperature feed liquid inlet of the membrane distillation component.

In some embodiments of the present invention, the permeate outlet of the membrane distillation module is connected to the permeate tank through the evaporator of the heat pump system.

In some embodiments of the present invention, the heat pump system includes a compressor, a condenser, a throttle valve and an evaporator connected in sequence.

In some embodiments of the present invention, the heat pump system further includes a regenerator for exchanging heat between the high-temperature heat pump working fluid from the evaporator and the low-temperature heat pump working fluid from the condenser.

In a second aspect of the present invention, a multi-system coupled heat, power and water cogeneration method is provided, including:

When the solar radiation is sufficient, the solar system provides users with electricity and hot water, and the membrane distillation system provides users with drinkable fresh water;

When the solar radiation is insufficient, the solar system provides part of the electricity and hot water for the user, the fuel cell system provides the electricity for the user, and the membrane distillation system provides the user with drinkable fresh water;

When there is no solar radiation, the hot water storage tank provides hot water for users, the fuel cell system provides electrical energy for users, and the membrane distillation system provides drinkable fresh water for users.

One or more technical solutions of the present invention have the following beneficial effects:

(1) The present invention introduces the membrane distillation system to recover the medium and low temperature waste heat of the fuel cell system and the solar energy system, produces drinkable fresh water, and improves the energy utilization efficiency; utilizes the organic combination of the heat pump system and the membrane distillation system to further improve the efficiency of the membrane distillation process. heat transfer efficiency.

(2) Based on the principle of energy cascade utilization, the present invention integrates a solar system, a water electrolyzer, a fuel cell system, a heat pump system and a membrane distillation system, has a good temperature matching effect, and can provide electric energy, drinkable fresh water, Domestic hot water and energy storage purposes.

(3) The multi-system coupled heat, power and water cogeneration system proposed by the present invention can continuously provide users with electric energy, drinkable fresh water and domestic hot water according to different operating conditions, and the entire system will not be affected by discontinuous solar energy.

(4) Multiple heat exchangers and regenerators are set in the multi-system coupled heat, power and water cogeneration system of the present invention, which can recycle the heat generated by each system, realize energy utilization maximization, and improve energy utilization rate .

(5) The multi-system coupling heat, power and water cogeneration system proposed by the present invention has a short construction period, convenient maintenance and can realize "unattended", and can be applied in remote areas including military fields, border defense areas, islands and public power grids that are difficult to cover Regions, to meet the needs of users for heat, electricity and water, to achieve energy conservation and emission reduction and to improve energy efficiency.

Description of drawings

Fig. 1 is a schematic structural diagram of a multi-system coupled heat, power and water cogeneration system according to Embodiment 1 of the present invention.

In the figure, 1. Solar photovoltaic photothermal integrated components, 2. DC controller, 3. The first DC/AC converter, 4. DC/DC converter, 5. PEM water electrolyzer, 6. The first electricity user , 7. Hydrogen storage bottle, 8. Air compressor, 9. Pressure reducing valve, 10. First confluence valve, 11. Air humidifier, 12. Hydrogen humidifier, 13. Hydrogen compressor, 14. PEMFC stack, 15. The first gas-liquid separator, 16. The second gas-liquid separator, 17. The second DC/AC converter, 18. The second electric user, 19. The second confluence valve, 20. The water storage tank, 21. The first One water pump, 22, the first heat exchanger, 23, the feed liquid tank, 24, the second water pump, 25, the second heat exchanger, 26, the fresh water user, 27, the permeate tank, 28, the third water pump, 29, Membrane distillation assembly, 30, evaporator, 31, throttle valve, 32, regenerator, 33, heat pump working fluid compressor, 34, condenser, 35, first valve, 36, second valve, 37, third Valve, 38, the fourth valve, 39, the hot water storage tank, 40, the fourth water pump, 41, the hot water user.

Detailed ways

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, it only means that it is consistent with the up, down, left and right directions of the accompanying drawings, and does not limit the structure. It is for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Example 1

In a typical implementation of the present invention, a multi-system coupled heat, power and water cogeneration system is proposed, as shown in Figure 1, including a solar energy system, a water electrolyzer system, a fuel cell system, a heat pump system and a membrane distillation system; The solar system and the fuel cell system provide users with electric energy and heat energy; the water electrolyzer system utilizes the electric energy provided by the solar system to produce hydrogen and provides it to the fuel cell system; the feed liquid treatment water of the membrane distillation system utilizes the solar system and the heat of the fuel cell system to produce drinkable fresh water; the heat pump system is coupled with a membrane distillation system through a condenser and an evaporator.

The solar energy system includes a solar photovoltaic photothermal integrated module (PVT) 1, the photovoltaic module in the solar photovoltaic photothermal integrated module is connected to the DC controller 2, and the photothermal module is connected to the fourth water pump 40 and the hot water storage tank 39 in sequence, One of the DC controllers 2 is connected to the first DC/AC converter 3 to provide electric energy for users, and the other is connected to the DC/DC converter 4 to provide electric energy for the water electrolyzer system, and the photovoltaic module converts solar energy into Electric energy, the DC controller 2 is used to control the DC power generated by the photovoltaic module, the first DC/AC converter 3 converts the DC power into AC power for the first electricity user 6, and the DC/DC converter 4 converts the DC power into the PEM The water electrolyzer 5 operates a matching direct current to produce hydrogen; the photothermal module converts solar energy into heat energy to heat the water, and the hot water is stored in the hot water storage tank 39 for heating the feed liquid and providing domestic hot water.

The water electrolyzer system includes a PEM water electrolyzer 5. The PEM water electrolyzer uses a solid proton exchange membrane as an electrolyte, uses pure water as a reactant, and uses electric energy to ionize water to generate hydrogen. The hydrogen outlet of the PEM water electrolyzer and the hydrogen storage bottle 7 connected, the hydrogen storage bottle stores the hydrogen.

The fuel cell system is a proton exchange membrane fuel cell (PEMFC) system, including a PEMFC stack 14, the hydrogen inlet of the PEMFC stack 14 is connected to the hydrogen storage bottle 7 through a pressure reducing valve 9, and the oxygen inlet is connected to the air compressor 8 Connected, the anode and cathode wet gas outlets of the PEMFC stack are provided with a first gas-liquid separator 15 and a second gas-liquid separator 16 for reclaiming the moisture in the anode and cathode outlet wet gases of the PEMFC stack, the first The liquid outlets of the gas-liquid separator 15 and the second gas-liquid separator 16 are connected to the water storage tank 20 through the second confluence valve 19, and the water storage tank stores the recovered moisture; the gas outlet of the first gas-liquid separator 15 is compressed by hydrogen. Machine 13 and the first confluence valve 10 enter the hydrogen pipeline, a hydrogen humidifier 12 is set between the hydrogen inlet of the PEMFC stack and the hydrogen storage bottle, an air humidifier 11 is set between the oxygen inlet and the air compressor 8, the hydrogen humidifier and the air The moisture of the humidifier comes from the water storage tank 20 , and the electric energy generated by the PEMFC stack is converted into alternating current through the second DC/AC converter 17 and then supplied to the second electric user 18 .

Since the fuel cell system will generate a large amount of heat, a first heat exchanger 22 is also provided in the fuel system. The first water pump 21 pumps water into the PEMFC stack to take away the heat generated by it, and then enters the first heat exchanger to convert the water into the first heat exchanger. The heat is exchanged to the feed liquid of the membrane distillation system, and the cooled water enters the PEMFC stack again for cooling, and this process is continuously cycled.

The membrane distillation system includes a membrane distillation assembly 29, a feed liquid tank 23 and a permeate tank 27, and the feed liquid outlet of the feed liquid tank 23 passes through the first heat exchanger 22 of the fuel cell system and the hot water storage tank of the solar energy system. 39 and the condenser 34 of the heat pump system are connected to the high-temperature feed liquid inlet of the membrane distillation assembly 29; the permeate outlet of the membrane distillation assembly is connected to the permeate tank 27 through the evaporator 30 of the heat pump system to provide fresh water for the fresh water user 26, Part of the fresh water in the permeate tank enters the membrane distillation assembly 29 again for circulation under the action of the third water pump.

Further, the high-temperature feed liquid outlet of the membrane distillation assembly 29 returns to the feed liquid tank 23 again through the second heat exchanger 25, and the feed liquid in the feed liquid tank enters the second heat exchanger 25 under the action of the second water pump 24 Heat exchange with the high-temperature liquid material from the membrane distillation component realizes the recovery and utilization of the heat of the high-temperature liquid material.

The heat pump system includes a heat pump working fluid compressor 33 , a condenser 34 , a throttle valve 31 and an evaporator 30 connected in sequence, forming a closed circulation loop of the thermal working fluid.

Further, the heat pump system further includes a regenerator 32 for exchanging heat between the high-temperature heat pump working fluid from the evaporator 30 and the low-temperature heat pump working fluid from the condenser 34 to improve energy utilization efficiency and reduce power consumption of the compressor.

In the multi-system coupled heat, power and water cogeneration system of this embodiment, a plurality of valves are set up, including the first valve 35, the second valve 36, the third valve 37, and the fourth valve 38, and different valves can be realized by changing the opening of the valves. operating conditions.

The multi-system coupled heat, power and water cogeneration system of the present invention includes the following operating conditions:

(1) When the solar radiation is sufficient

The solar system provides the electrical energy required by the user and the thermal energy required for the membrane distillation process.

Part of the direct current generated by the PVT components of the solar system is converted into alternating current through the DC/AC converter 3 to provide electric energy for users, and the other part is converted into direct current matching the operation of the PEM water electrolyzer 5 through the DC/DC converter 4 to produce hydrogen. Store in the hydrogen storage bottle 7 to realize the energy storage process. In addition, the thermal energy generated by the solar PVT components is stored in the hot water storage tank 39, a part of the thermal energy is used to heat the material liquid, and the other part is used to provide domestic hot water for users.

Through the second heat exchanger 25, the high-temperature feed liquid from the membrane distillation assembly 29 is used to preheat the low-temperature feed liquid from the feed liquid tank 23 to improve energy utilization efficiency; at this time, the second valve 36 and the third valve 37 are closed, The first valve 35 and the fourth valve 38 are opened, and the preheated feed liquid first flows through the hot water storage tank 39 to absorb heat, then enters the condenser 34 to absorb the heat of the heat pump working fluid, and then enters the membrane distillation component 29 to complete a cycle At the same time, the low-temperature permeate in the permeate tank 27 is pumped into the membrane distillation assembly 29 by the third water pump 28 to complete the membrane distillation process; the high-temperature permeate from the membrane distillation assembly 29 enters the evaporator 30 of the heat pump system and heat pump workers heat exchange with the liquid, release heat, and then flow back to the permeate tank 27 to complete a cycle to provide users with drinkable fresh water.

The high-temperature and high-pressure gaseous heat pump working medium in the heat pump system enters the condenser 34 to release heat, then enters the regenerator 32 to further release heat, and then enters the throttle valve 31 to become a low-temperature and low-pressure liquid working medium, and then enters the evaporator 30 to absorb the permeate The heat then enters the regenerator 32 to further absorb heat and become a gaseous working medium, and then enters the heat pump working medium compressor 33 to complete a cycle; by setting the regenerator 32, energy utilization efficiency is improved and the power consumption of the compressor is reduced.

(2) When the solar radiation is insufficient

Together, the solar system and the fuel cell system provide the electrical energy required by the user and the thermal energy required for the membrane distillation process.

The direct current generated by the PVT components of the solar system is all converted into alternating current through the DC/AC converter 3 to provide electric energy for the user; the thermal energy generated by the PVT component is stored in the hot water storage tank 39, a part of the thermal energy is used for heating the feed liquid, and the other part is used for the user Provide domestic hot water.

The fuel cell system uses the hydrogen stored in the hydrogen storage bottle to generate electricity, heat and water; the direct current generated by the PEMFC stack is converted into alternating current through the second DC/AC converter 17 to provide electric energy for the user; the first water pump 21 and the first The heat exchanger 22 is connected by pipelines to form a thermal management cycle. The cooling liquid takes away the waste heat generated by the PEMFC stack, and heats the feed liquid through the first heat exchanger 22 to release heat; the first gas-liquid separator 15 and the second gas-liquid The separator 16 collects the moisture in the wet gas at the outlet of the anode and the cathode respectively, and stores it in the water storage tank 20 to replenish water for the air humidifier 11 and the hydrogen humidifier 12, forming a water management cycle.

At this time, the second valve 36 and the fourth valve 38 are opened, the first valve 35 and the third valve 37 are closed, and the feed liquid preheated by the second heat exchanger 25 first enters the first heat exchanger 22 to absorb the cooling liquid. heat, then flows through the hot water storage tank 39 to absorb heat, then enters the condenser 34 to absorb the heat of the heat pump working medium, and finally enters the membrane distillation component 29 to complete a cycle; the circulation mode of the permeate and the circulation mode of the heat pump are consistent with the solar energy sufficient working The situation is the same.

(3) When there is no solar radiation (at night or in bad weather)

The fuel cell system provides the electrical energy required by the user and the thermal energy required for the membrane distillation process.

The hot water stored in the hot water storage tank 39 can provide domestic hot water for users, and the fuel cell system uses the hydrogen stored in the hydrogen storage bottle to generate electricity, heat and water.

At this time, the second valve 36 and the third valve 37 are opened, the first valve 35 and the fourth valve 38 are closed, and the feed liquid preheated by the second heat exchanger 25 first enters the first heat exchanger 22 to absorb the cooling liquid. The heat then enters the condenser 34 to absorb the heat of the heat pump working fluid, and then enters the membrane distillation assembly 29 to complete a cycle; the rest of the system is the same as the cycle of the above two working conditions.

Example 2

In a typical implementation of the present invention, a multi-system coupled heat, power and water cogeneration method is proposed, including:

When the solar radiation is sufficient, the solar system provides electricity and hot water for users, the membrane distillation system provides drinkable fresh water for users, and the heat pump system provides heat/cooling for users;

When the solar radiation is insufficient, the solar system provides part of the electric energy and hot water for the user, the fuel cell system provides electric energy for the user, the membrane distillation system provides drinking fresh water for the user, and the heat pump system provides heat/cooling for the user;

When there is no solar radiation, the hot water storage tank provides users with hot water, the fuel cell system provides users with electrical energy, the membrane distillation system provides users with drinkable fresh water, and the heat pump system provides users with heat/cooling capacity.

The embodiments described above have described the technical solutions of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. All done within the principle scope of the present invention Any modification, supplement or substitution in a similar manner shall be included within the protection scope of the present invention.

Claims (10)

1. A multi-system coupled combined heat, power and water supply system is characterized by comprising a solar system, a water electrolyzer system, a fuel cell system, a heat pump system and a membrane distillation system;

the solar energy system and the fuel cell system provide electric energy and heat energy for users; the water electrolyzer system utilizes the electric energy provided by the solar energy system to prepare hydrogen which is provided to the fuel cell system; the feed liquid treatment water of the membrane distillation system utilizes the heat of a solar system and a fuel cell system to prepare drinkable fresh water; the heat pump system is coupled to the membrane distillation system through a condenser and an evaporator.

2. The multi-system coupled combined heat and power water supply system of claim 1, wherein the solar system comprises a solar photovoltaic and photo-thermal integrated module, wherein the photovoltaic module is connected with the direct current controller, and the photo-thermal module is connected with the water pump hot water storage tank in sequence.

3. A multi-system coupled combined heat and power water supply system as claimed in claim 2 wherein one of said DC controllers is connected to a DC/AC converter to provide power to a user and the other is connected to a DC/DC converter to provide power to a water electrolyser system.

4. The multi-system coupled combined heat and power water supply system as claimed in claim 1, wherein the water electrolyzer system comprises a PEM water electrolyzer, and the hydrogen outlet of the PEM water electrolyzer is connected with a hydrogen storage bottle.

5. The multi-system coupled combined heat and power water supply system according to claim 4, wherein the fuel cell system comprises a PEMFC stack, a hydrogen inlet of the PEMFC stack is connected with a hydrogen storage bottle, an oxygen inlet of the PEMFC stack is connected with an air compressor, wet gas outlets of an anode and a cathode of the PEMFC stack are respectively provided with a gas-liquid separator, and a liquid outlet of the gas-liquid separator is connected with a water storage tank.

6. The multi-system coupled combined heat and power system according to claim 1, wherein the membrane distillation system comprises a membrane distillation assembly, a feed liquid tank and a permeate tank, and a feed liquid outlet of the feed liquid tank is connected with a high-temperature feed liquid inlet of the membrane distillation assembly through a heat exchanger of the fuel cell system, a hot water storage tank of the solar energy system and a condenser of the heat pump system.

7. The multi-system coupled combined heat and power water system as claimed in claim 6, wherein the permeate outlet of the membrane distillation module is connected to the permeate tank via an evaporator of the heat pump system.

8. The multi-system coupled combined heat and power system of claim 1, wherein the heat pump system comprises a compressor, a condenser, a throttle valve and an evaporator connected in series.

9. The multi-system coupled combined heat and power system of claim 8, wherein the heat pump system further comprises a regenerator for exchanging heat between the high temperature heat pump working fluid from the evaporator and the low temperature heat pump working fluid from the condenser.

10. A multi-system coupled cogeneration method employing the multi-system coupled cogeneration system of any one of claims 1-9, comprising:

when the solar radiation is sufficient, the solar system provides electric energy and hot water for the user, and the membrane distillation system provides drinkable fresh water for the user;

when solar radiation is insufficient, the solar energy system provides partial electric energy and hot water for a user, the fuel cell system provides electric energy for the user, and the membrane distillation system provides drinkable fresh water for the user;

when solar radiation does not exist, the heat storage water tank provides hot water for a user, the fuel cell system provides electric energy for the user, and the membrane distillation system provides drinkable fresh water for the user.

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