Pure water supply pipeline system for producing hydrogen by electrolyzing water

Abstract

The invention discloses a pure water supply pipeline system for producing hydrogen by electrolyzing water. A heat exchange pipeline is arranged in the pure water supply pipeline system, and the heat exchange pipeline is used for carrying out heat exchange on a water body before flowing through a make-up pump (72) and a water body after flowing through the make-up pump; the heat exchange pipeline comprises a cooling water supply source (3), a first heat exchanger (81) and a second heat exchanger (82); the first heat exchanger is arranged between a pipeline at a water outlet pipe orifice of the pure water storage tank (1) and a cooling water circulation pipeline, and the second heat exchanger is arranged between a pipeline for communicating a main port of a second three-way valve (92) to a deionizer (4) and the cooling water circulation pipeline; water flow in the cooling water circulation pipeline passes through the second heat exchanger and then passes through the first heat exchanger after being supplied by the cooling water supply source. The heat exchange pipeline arranged in the pure water supply pipeline system helps to cool high-temperature pure water, and meanwhile, heat is transferred to preheat normal-temperature pure water, so that waste heat is secondarily utilized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of proton exchange membrane (PEM) electrolysis of water to produce hydrogen, and particularly relates to a pure water supply system through resource utilization of wastewater, recovery of cooling water waste heat and solar heating, aiming to realize independent optimization and collaborative energy saving of the heating and cooling links in pure water supply. BACKGROUND

[0002] In the industrialization process of PEM electrolysis of water to produce hydrogen, the following technical difficulties exist:

[0003] Firstly, the wastewater containing trace electrolytes discharged from the pure water storage tank is directly discharged, resulting in waste of water resources. The existing wastewater treatment scheme only focuses on the discharge problem after purification, and lacks a recycling design (see Su Jiaxin, Wu Jiang, Meng Xiangrui, et al. Application of electrolysis of water to produce hydrogen in wastewater treatment [J]. Cleaning World, 2024, 40(10): 13-15.);

[0004] Secondly, the traditional oxygen cooler (E-0102) needs to continuously consume external cooling water to reduce the temperature of oxygen, which has high energy consumption and does not fully utilize internal resources. The traditional cooling water system operates independently and cannot be coupled with the wastewater treatment link (see Yang Gui. An automatic cooling water circulation device for a water electrolysis hydrogen production equipment: 201921980411.6 [P]. 2020-09-29.);

[0005] Thirdly, the waste heat of the cooling water in the heat exchanger (E-0101) is not effectively utilized, resulting in a decrease in the overall energy efficiency of the system (see Zhou Wenli, Ju Bingzhong, Zhang Wei, et al. Development of an automatic cooling water circulation device for a water electrolysis hydrogen production equipment [J]. Qinghai Science and Technology, 2019, 26(02): 85-88.);

[0006] Fourthly, the traditional pure water heating relies on electric heating, which has a high energy consumption ratio (see Shanghai Hydrogen Energy Technology Co., Ltd. Multifunctional hydrogen production circulation system and control method: 202510185804.1 [P]. 2025-03-18.).

[0007] In summary, the main problems at present are:

[0008] 1) The existing pure water supply pipeline system has a low waste heat utilization rate. The cooling water in the heat exchanger is directly discharged after heat exchange, and the waste heat is not utilized, resulting in waste of waste heat.

[0009] In addition, there are also some secondary problems:

[0010] 2) In the existing pure water supply pipeline system, the heat pump is provided with heat by the electric heater 5, which has a relatively low energy consumption, increasing the power consumption of the entire system;

[0011] 3) The existing pure water supply pipeline system has trace electrolyte wastewater directly discharged, resulting in waste of water resources. SUMMARY

[0012] The present application aims to provide a pure water supply pipeline system for water electrolysis hydrogen production, which uses heat exchange pipeline to transfer heat between high-temperature pure water and normal-temperature pure water, thereby saving overall energy consumption.

[0013] In order to achieve the above technical purpose, the present application adopts the following technical solutions:

[0014] A pure water supply pipeline system for water electrolysis hydrogen production is provided, which is provided with a water replenishing pump, and is also provided with a heat exchange pipeline, which exchanges heat between water before flowing through the water replenishing pump and water after flowing through the water replenishing pump.

[0015] A pure water supply pipeline system for water electrolysis hydrogen production includes a pure water storage tank, an oxygen water primary distribution tank, an electrolytic cell, a first three-way valve and a second three-way valve, and is also provided with a waste discharge port and an oxygen outlet port; the water outlet port of the pure water storage tank is connected to the main port of the first three-way valve, and the first switching port of the first three-way valve is connected to the waste discharge port; the second switching port of the first three-way valve is connected to the first switching port of the second three-way valve, and a water replenishing pump is arranged in the pipeline from the second switching port of the first three-way valve to the first switching port of the second three-way valve; the main port of the second three-way valve is connected to the oxygen water primary distribution tank through a pipeline, and the oxygen water primary distribution tank is connected to the second switching port of the second three-way valve through another pipeline; the oxygen water primary distribution tank is connected to the water inlet of the electrolytic cell through a pipeline, and an electrolytic cell circulating pump is arranged in the pipeline from the oxygen water primary distribution tank to the electrolytic cell; the anode side of the electrolytic cell is connected to the oxygen water primary distribution tank through a pipeline; the oxygen water primary distribution tank is connected to the oxygen outlet port; the pure water supply pipeline system further includes a cooling water supply source, a first heat exchanger and a second heat exchanger; a cooling water circulating pipeline is constructed based on the cooling water supply source, the first heat exchanger is arranged between the pipeline at the water outlet port of the pure water storage tank and the cooling water circulating pipeline, and the second heat exchanger is arranged between the pipeline from the main port of the second three-way valve to the oxygen water primary distribution tank and the cooling water circulating pipeline; after water flow in the cooling water circulating pipeline is supplied by the cooling water supply source, it first passes through the second heat exchanger and then passes through the first heat exchanger.

[0016] Further, a deionizer and an electric heater are arranged in the pipeline from the main port of the second three-way valve to the oxygen water primary distribution tank in sequence, and a deionization circulating pump is arranged in the pipeline from the oxygen water primary distribution tank to the second switching port of the second three-way valve.

[0017] Further, the electric heater is powered by a photovoltaic panel.

[0018] Further, the pure water supply pipeline system further comprises a third heat exchanger, which is arranged between the pipeline connected to the waste outlet and the pipeline connected to the oxygen outlet.

[0019] Further, the pure water storage tank receives hydrogen side return water.

[0020] Further, the pure water storage tank is provided with an electric conductivity sensor, and the first three-way valve is controlled by the electric conductivity sensor.

[0021] Further, when the electric conductivity of the pure water in the pure water storage tank is greater than 0.2 muS / cm, the first three-way valve is switched to the first switching port, and is connected to the waste outlet through the pipeline, until the electric conductivity of the pure water in the pure water storage tank is less than 0.15 muS / cm, the first three-way valve is switched to the second switching port.

[0022] Further, a waste water storage tank and a heat pump are arranged in the pipeline from the first switching port of the first three-way valve to the waste outlet.

[0023] Further, the pure water supply pipeline system further comprises an electric heating rod, a phase change heat storage tank, a flow control pump, a third three-way valve and a fourth three-way valve; the first switching port of the third three-way valve is connected to the oxygen water primary distribution tank, and the electric heater is arranged in the pipeline from the first switching port of the third three-way valve to the oxygen water primary distribution tank; the second switching port of the third three-way valve is connected to the fourth three-way valve through the pipeline, and the flow control pump and the phase change heat storage tank are arranged in the pipeline from the second switching port of the first three-way valve to the fourth three-way valve in sequence, and the phase change heat storage tank is arranged on the water outlet side of the flow control pump; the first switching port of the fourth three-way valve is connected to the oxygen water primary distribution tank through the pipeline, and the second switching port of the fourth three-way valve is connected to the electric heater through the pipeline.

[0024] The pure water supply pipeline system for electrolytic water hydrogen production of the present application has the following main beneficial effects compared with the prior art:

[0025] 1) The heat exchange pipeline is arranged in the pure water supply pipeline system of the present application, which helps to cool the high-temperature pure water, and at the same time, transfers the heat to preheat the normal-temperature pure water, so that the waste heat is utilized twice.

[0026] In addition, the pure water supply pipeline system of the present application also has other beneficial effects:

[0027] 2) In the pure water supply pipeline system of the present application, an electric heater and a photovoltaic panel are arranged, and the photovoltaic panel converts solar energy into electric energy, which is stored in the battery to a certain amount of electricity, and then powers the electric heater, thereby reducing the system power consumption;

[0028] 3) In the pure water supply pipeline system of the present application, a waste water storage tank, a heat exchange pump and a third heat exchanger are arranged. The waste water is introduced into the waste water storage tank by the three-way valve for storage, and then pumped into the heat exchanger by the heat exchange pump to exchange heat with oxygen, so that the oxygen is cooled to achieve cooling effect, and the use of original cooling water is reduced, and the waste water is reused. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the pure water supply pipeline system for electrolyzing water to produce hydrogen based on the embodiment 1 of the present application;

[0030] Figure 2 It is a flow chart of the control method of the pure water supply pipeline system based on the embodiment 1 of the present application;

[0031] Figure 3 It is a control flow chart of the electric heater in the pure water supply pipeline system based on the embodiment 1 of the present application;

[0032] Figure 4 It is a schematic diagram of the pure water supply pipeline system based on the embodiment 2 of the present application;

[0033] Figure 5 It is a control flow chart of photovoltaic energy storage and power generation of the pure water supply pipeline system based on the embodiment 2 of the present application. DETAILED DESCRIPTION

[0034] Before introducing the specific embodiments, the professional terms related to the invention are introduced first:

[0035] 1) The three-way valve mentioned in this paper is a pipeline device of prior art, which has three ports, one of which is called the main port, and the other two are called the switching ports;

[0036] For convenience of description, the two switching ports are defined as "first switching port" and "second switching port" respectively in this paper.

[0037] It should be noted that the three-way valve used in this paper is an electrically controlled valve.

[0038] 2) The electrolytic cell 6 mentioned in this paper is a device of prior art, which is a device for directly implementing electrolytic water treatment. The electrolytic cell 6 has a pure water inlet, an anode side and a cathode side. The pure water inlet functions to allow the pure water required for electrolysis of the electrolytic cell 6 to enter from the port. The anode side functions to allow the oxygen and water obtained after the electrolytic cell 6 works to flow out from the channel. The cathode side functions to allow the hydrogen obtained after the electrolytic cell 6 works to flow out from the channel. The specific function implementation of the electrolytic cell 6 is common knowledge known by those skilled in the art.

[0039] In order to facilitate the description of the technical solutions in the following, the following definitions are made in advance:

[0040] Definition 1: The "cooling water" referred to herein is the water body for cooling supplied by the cooling water supply source 3.

[0041] Definition 2: The "hydrogen side return water" referred to herein is the water body separated from the water vapor contained in the hydrogen gas produced by the cathode side of the electrolytic cell 6 after cooling and gas-water separation.

[0042] The specific embodiments of the present application are further described below:

[0043] Embodiment 1:

[0044] Referring to Figure 1 , Figure 2 and Figure 3 , the embodiment 1 provides a pure water supply pipeline system for hydrogen production by electrolysis of water.

[0045] Referring to Figure 1 , the pure water supply pipeline system of the embodiment 1 mainly includes a pure water storage tank 1, an oxygen water primary separation tank 2, a cooling water supply source 3, a deionizer 4, an electric heater 5 and an electrolytic cell 6.

[0046] The pure water supply pipeline system further includes three heat exchangers, namely a first heat exchanger 81, a second heat exchanger 82 and a third heat exchanger 83.

[0047] The pure water supply pipeline system of the embodiment 1 is provided with two three-way valves, namely a first three-way valve 91 and a second three-way valve 92.

[0048] The pure water supply pipeline system of the embodiment 1 is provided with four water pumps, namely a heat exchange pump 71, a water replenishment pump 72, a deionization circulating pump 73 and an electrolytic cell circulating pump 74.

[0049] The pure water supply pipeline system of the embodiment 1 further has three external pipe openings, namely a waste discharge pipe opening, an oxygen outlet pipe opening and a hydrogen outlet pipe opening. The waste discharge pipe opening is used for discharging waste water externally; the oxygen outlet pipe opening is used for outputting the oxygen produced by electrolysis of water externally; and the hydrogen outlet pipe opening is used for outputting the hydrogen produced by electrolysis of water externally (see the specific description below).

[0050] The pure water storage tank 1 is used for receiving and storing pure water (water body for electrolysis of water), wherein the pure water is mainly pure water introduced from outside. In addition, in order to save water, part of the hydrogen side return water is also included in the pure water.

[0051] For the convenience of description, hereinafter, the "externally introduced pure water" is referred to as "externally supplied water" for short. It should be noted that the externally supplied water is deionized pure water.

[0052] That is, the pure water stored in the pure water storage tank 1 is a mixed water body of the hydrogen side return water and the externally supplied water. The pure water storage tank 1 is equivalent to the water supply source of the entire pure water supply pipeline system, and provides water source for the entire electrolytic water process.

[0053] Specifically,

[0054] The pure water storage tank 1 has three water inlets, two of which are water inlets, and the other is a water outlet. The two water inlets are used to receive the externally supplied water and the hydrogen side return water respectively, and the water outlet of the pure water storage tank 1 is connected to the main port of the first three-way valve 91 through a pipeline.

[0055] The first switching port of the first three-way valve 91 is connected to the waste discharge port through a pipeline, and the waste discharge storage tank 11 and the heat exchange pump 71 are sequentially arranged in the pipeline from the "first switching port of the first three-way valve 91" to the "waste discharge port". The water pumping direction of the heat exchange pump 71 is towards the waste discharge port, that is, the waste discharge storage tank 11 is on the water inlet side of the heat exchange pump 71, and the waste discharge port is on the water outlet side of the heat exchange pump 71.

[0056] The second switching port of the first three-way valve 91 is connected to the first switching port of the second three-way valve 92 through a pipeline, and the water supplement pump 72 is arranged in the pipeline from the "second switching port of the first three-way valve 91" to the "first switching port of the second three-way valve 92". The water pumping direction of the water supplement pump 72 is towards the "first switching port of the second three-way valve 92", that is, the first three-way valve 91 is on the water inlet side of the water supplement pump 72, and the second three-way valve 92 is on the water outlet side of the water supplement pump 72.

[0057] The main port of the second three-way valve 92 is connected to the oxygen water primary distribution tank 2 through a pipeline, and then the oxygen water primary distribution tank 2 is connected to the second switching port of the second three-way valve 92 through a pipeline.

[0058] The deionizer 4 and the electric heater 5 are sequentially arranged in the pipeline from the "main port of the second three-way valve 92" to the oxygen water primary distribution tank 2, and the deionization circulating pump 73 is arranged in the pipeline from the oxygen water primary distribution tank 2 to the "second switching port of the second three-way valve 92".

[0059] It should be noted that the electric heater 5 is powered by a photovoltaic cell panel 51.

[0060] The oxygen water primary distribution tank 2 is connected to the water inlet of the electrolytic tank 6 through a pipeline, and an electrolytic tank circulating pump 74 is arranged in the pipeline to pump the water in the oxygen water primary distribution tank 2 into the electrolytic tank 6 for electrolytic water treatment.

[0061] The anode side of the electrolytic tank 6 is connected to the oxygen water primary distribution tank 2 through a pipeline, and the cathode side of the electrolytic tank 6 is connected to the hydrogen outlet through a pipeline.

[0062] The oxygen water primary distribution tank 2 is also provided with a pipeline for outputting oxygen, and the oxygen water primary distribution tank 2 is connected to the oxygen outlet through the pipeline.

[0063] The combination of the oxygen water primary distribution tank 2 and the electrolytic tank 6 can implement the traditional electrolytic water process.

[0064] A cooling water circulating pipeline is constructed based on the cooling water supply source 3, and the first heat exchanger 81 is arranged between the pipeline connecting the pure water tank 1 water outlet to the main port of the first three-way valve 91 and the cooling water circulating pipeline, and heat exchange is performed between the two pipelines through the first heat exchanger 81.

[0065] The second heat exchanger 82 is arranged between the pipeline connecting the main port of the second three-way valve 92 to the oxygen water primary distribution tank 2 and the cooling water circulating pipeline, and heat exchange is performed between the two pipelines through the second heat exchanger 82. According to the water flow direction in the cooling water circulating pipeline, the water flow in the cooling water circulating pipeline is first supplied from the cooling water supply source 3, then passes through the second heat exchanger 82, then passes through the first heat exchanger 81, and then returns to the cooling water supply source 3, forming a loop.

[0066] In summary, the cooling water supply source 3 and the cooling water circulating pipeline essentially constitute a heat exchange pipeline for heat exchange between the normal temperature water before passing through the water replenishing pump 72 and the high temperature water after passing through the water replenishing pump 72.

[0067] It should be noted that the cooling water supply source 3 refers to a device or pipeline capable of supplying cooling water.

[0068] In addition, the third heat exchanger 83 is arranged between the pipeline connected to the waste outlet and the pipeline connected to the oxygen outlet, and heat exchange is performed between the two pipelines through the third heat exchanger 83.

[0069] The first heat exchanger 81 functions to exchange heat between the cooling water whose temperature has been raised to 30-50℃ after heat exchange in the second heat exchanger 82 and the pure water which maintains a normal temperature (25℃), so that the temperature of the pure water is raised, thereby reducing the energy consumption of the water replenishing pump 72.

[0070] The second heat exchanger 82 functions to cool the water pumped by the deionization circulating pump 73 and the water pumped by the make-up water pump 72, so that the temperature of the water reaches the working temperature requirement of the deionizer 4, and the deionizer 4 can work normally.

[0071] The third heat exchanger 83 functions to cool the oxygen gas discharged from the oxygen water primary separation tank 2 by heat exchange between the normal temperature (about 25℃) waste water pumped by the heat exchange pump 71 and the oxygen gas, so that the oxygen gas is cooled to a suitable temperature, which is conducive to subsequent work.

[0072] In the first embodiment, the first three-way valve 91 is controlled by the conductivity sensor installed on the pure water storage tank 1. Specifically, when the conductivity of the pure water in the pure water storage tank 1 is greater than 0.2 μS / cm, the first three-way valve 91 is switched to the first switching port, and is connected to the waste discharge port through the pipeline, with a flow rate consistent with the hydrogen side backwater flow rate. The waste water enters the waste water storage tank 11, and at the same time, the external water enters the pure water storage tank 1 at the hydrogen side backwater flow rate, so that the liquid level of the pure water storage tank 1 remains relatively stable. When the conductivity of the pure water in the pure water storage tank 1 is less than 0.15 μS / cm, the external water stops being input, and the first three-way valve 91 is switched to the second switching port, and the pure water enters the second heat exchanger 82 through the make-up water pump 72.

[0073] In the first embodiment, the second three-way valve 92 is fully open after the system is started, and is closed after the system is powered off.

[0074] The pure water supply pipeline system of the first embodiment has the following operation process and working principle:

[0075] The pure water storage tank 1 receives and stores the hydrogen side backwater and the external water as pure water. The pure water storage tank 1 is provided with a conductivity sensor for detecting the conductivity of the pure water in the pure water storage tank 1. The first three-way valve 91 is controlled by the conductivity sensor. When it is detected that the conductivity of the pure water in the pure water storage tank 1 exceeds the pre-set threshold value of 0.2 μS / cm, the first three-way valve 91 is switched to the first switching port, and is connected to the waste discharge port through the pipeline, with a flow rate consistent with the hydrogen side backwater flow rate. The waste water enters the waste water storage tank 11, and under the driving action of the heat exchange pump 71, the water in the waste water storage tank 11 is discharged from the waste discharge port. At this time, the external water enters the pure water storage tank 1 at the hydrogen side backwater flow rate, so that the liquid level of the pure water storage tank 1 remains relatively stable. When the conductivity of the pure water in the pure water storage tank 1 is less than 0.15 μS / cm, the external water stops being input, and the first three-way valve 91 is switched to the second switching port.

[0076] Under the driving action of the make-up water pump 72, the water in the pure water storage tank 1 enters the oxygen water primary separation tank 2 through the first heat exchanger 81, the second heat exchanger 82, the deionizer 4 and the electric heater 5.

[0077] At the first heat exchanger 81, heat is transferred from the pure water in the second heat exchanger 82 to the cooling water delivered to the second heat exchanger 82 from the cooling water supply source 3, and the cooling water after heat exchange at the second heat exchanger 82 exchanges heat with the pure water in the first heat exchanger 81, so that the heat in the cooling water is transferred to the pure water to make the pure water get warmed up.

[0078] At the second heat exchanger 82, the pure water in the second heat exchanger 82 is transferred to the cooling water delivered to the second heat exchanger 82 from the cooling water supply source 3, so that the pure water in the second heat exchanger 82 gets the effect of cooling to meet the requirements of normal operation of the deionizer 4.

[0079] At the deionizer 4, the conductivity of the pure water is reduced after passing through the deionizer 4, and at the electric heater 5, the pure water is heated to meet the requirements of normal operation of the electrolytic cell 6, and the photovoltaic cell panel 51 is coupled to the power grid to supply power to the electric heater 5, and when the electric energy generated by the photovoltaic cell panel 51 can meet the operation of the heat pump, it is switched to photovoltaic cell power supply, and if the electric energy generated by the photovoltaic cell panel 51 cannot meet the operation of the heat pump (such as at night without solar energy), it is switched to power grid power supply.

[0080] At the electrolytic cell 6, the pure water enters the electrolytic cell 6 through the pure water inlet, and the water is decomposed into oxygen and hydrogen in the electrolytic cell 6, the hydrogen gas flows out from the cathode side of the electrolytic cell, and the oxygen and water flow out from the anode side of the electrolytic cell.

[0081] At the heat pump 71, the waste water in the waste water storage tank 11 is pumped into the third heat exchanger 83 by the heat pump 71. At the make-up water pump 72, the pure water after heat exchange in the first heat exchanger 81 is pumped into the second heat exchanger 82 by the make-up water pump 72, which is controlled by the liquid level and conductivity of the oxygen water primary distribution tank 2, when the liquid level of the oxygen water primary distribution tank 2 is less than a constant value 1, the make-up water pump 72 is started, until its liquid level is greater than a constant value 2, when the conductivity of the oxygen water primary distribution tank 2 is > 0.2 μS / cm and the deionization circulating pump 73 power reaches 120% and runs to a specified time 1, the deionization circulating pump 73 stops, the make-up water pump 72 starts and starts timing 2, if the specified time 2 is reached, the conductivity is still higher than the threshold value, the system stops, and the fault is checked, if the conductivity is < 0.2 μS / cm within the specified time 2, the make-up water pump 72 stops.

[0082] In the deionization circulating pump 73, the pure water in the oxygen water primary distribution tank 2 is pumped into the second heat exchanger 82 by the deionization circulating pump 73, which is controlled by the conductivity of the oxygen water primary distribution tank 2. When the conductivity of the oxygen water primary distribution tank 2 is <0.2 μS / cm, the deionization circulating pump 73 operates normally. When the conductivity of the oxygen water primary distribution tank 2 is >0.2 μS / cm, the deionization circulating pump 73 reaches 120% power and starts timing 1. If the specified time 1 is reached and the conductivity is still higher than the threshold, the deionization circulating pump 73 stops running. At this time, the make-up pump 72 starts and starts timing 2. If the specified time 2 is reached and the conductivity is still higher than the threshold, the system stops and the fault is checked.

[0083] In the electrolytic tank circulating pump 74, the pure water in the oxygen water primary distribution tank 2 is pumped into the electrolytic tank 6 by the electrolytic tank circulating pump 74, which is controlled by the conductivity of the oxygen water primary distribution tank 2. When the conductivity of the oxygen water primary distribution tank 2 is <0.2 μS / cm, the electrolytic tank circulating pump 74 operates normally. When the conductivity of the oxygen water primary distribution tank 2 is >0.2 μS / cm, the electrolytic tank circulating pump 74 stops running.

[0084] In the pure water supply pipeline system of the present embodiment 1, a cooling water supply source 3, a first heat exchanger 81 and a second heat exchanger 82 are provided. Since the cooling water supplied by the cooling water supply source 3 helps to cool the high-temperature pure water through the second heat exchanger 82, and at the same time transfers heat to the cooling water, which is then preheated in the first heat exchanger 81, the waste heat is utilized twice. Thus, the problem 1 mentioned in the background art is solved: "the waste heat in the heat exchanger is directly discharged after heat exchange, and the waste heat is not utilized, resulting in waste of waste heat".

[0085] In the pure water supply pipeline system of the present embodiment 1, an electric heater 5 and a photovoltaic panel 51 are provided. Since the photovoltaic panel 51 absorbs solar energy and converts it into electrical energy, which is stored in the battery to a certain amount of electricity, and then supplies power to the electric heater 5. When the battery power is not enough to support the operation of the electric heater 5, the power grid supplies power to the electric heater 5, which reduces the power consumption of the system. Thus, the problem 2 mentioned in the background art is solved: "the heat pump is provided with heat by the electric heater 5, the electric heater 5 has low energy consumption, and the power consumption of the whole system is increased".

[0086] In the pure water supply pipeline system of the present embodiment 1, the waste water storage tank 11, the heat pump 71 and the third heat exchanger 83 are arranged, and the waste water is introduced into the waste water storage tank 11 for storage by the three-way valve, and then the waste water is pumped into the heat exchanger by the heat pump 71 to exchange heat with the oxygen, so that the oxygen is cooled to achieve the cooling effect, and the use of the original cooling water is reduced, and the waste water is reused. Thus, the problem 3 mentioned in the background art is solved: "In the existing pure water supply pipeline system, a small amount of electrolyte waste water is directly discharged, resulting in waste of water resources".

[0087] Embodiment 2:

[0088] Referring to Figure 4 and Figure 5 , the pure water supply pipeline system of the present embodiment 2 is based on the technical solution of the embodiment 1, and the electric heating rod 52, the phase change heat storage tank 53, the flow control pump 75, the third three-way valve 93 and the fourth three-way valve 94 are additionally arranged.

[0089] Specifically,

[0090] The first switching port of the third three-way valve 93 is connected to the oxygen water primary distribution tank 2 through a pipeline, and an electric heater 5 is arranged in the pipeline from the "first switching port of the third three-way valve 93" to the "oxygen water primary distribution tank 2".

[0091] The second switching port of the third three-way valve 93 is connected to the fourth three-way valve 94 through a pipeline, and the flow control pump 75 and the phase change heat storage tank 53 are arranged in the pipeline from the "second switching port of the first three-way valve 91" to the "fourth three-way valve 94" in sequence, and the water pumping direction of the flow control pump 75 is towards the first switching port of the fourth three-way valve 94, that is, the third three-way valve 93 is on the water inlet side of the flow control pump 75, and the phase change heat storage tank 53 is on the water outlet side of the flow control pump 75.

[0092] The first switching port of the fourth three-way valve 94 is connected to the oxygen water primary distribution tank 2 through a pipeline, and the second switching port of the fourth three-way valve 94 is connected to the electric heater 5 through a pipeline.

[0093] Specifically,

[0094] The existing electric heater relies on the power grid, and accounts for about 30% of the energy consumption of the whole system. Considering the use of photovoltaic power supply, the power grid is switched in rainy days and at night to reduce energy efficiency, but the surplus of photovoltaic power is not fully utilized, and the light abandonment rate is as high as 15%. Considering adding a phase change heat storage tank downstream of the electric heater, heat is stored during the day when photovoltaic power is surplus, and heat is released at night to heat water. At the same time, based on the weather forecast, the threshold of the heat storage temperature is adjusted, photovoltaic power is preferentially used, then the heat storage is used, and finally the power grid is switched. Not only does it solve the problem of dependence on the power grid for the initial heat pump, but it also meets the standard of "green hydrogen" certification, and solves the problem of photovoltaic light abandonment and the contradiction between energy demand and photovoltaic power generation peak and night heat demand.

[0095] The main problem to be solved is that the electric heater relies on the power grid, and accounts for about 30% of the energy consumption of the whole system. Most of the power grid is thermal power, which is contrary to the concept of "green hydrogen", and the energy consumption is relatively high.

[0096] The solution is to use photovoltaic power generation and heat storage to meet the demand of the electric heater for heating pure water, reduce the power supply proportion of the power grid to less than 10%, meet the concept of "green hydrogen", reduce system energy consumption, and achieve cost reduction and efficiency improvement.

[0097] Specific measures: Since solar energy is periodic, it is divided into three stages.

[0098] The first stage: when the solar energy is sufficient, the third three-way valve 93 supplies photovoltaic power to the electric heater 5, so that the pure water reaches 80 DEG C, meets the demand of the electrolytic cell 6, and the excess solar energy heats the phase change material in the phase change heat storage tank 53 to liquefy and store heat.

[0099] The second stage: when the solar energy is not enough to heat the pure water in the electric heater 5 to 80 DEG C, the photovoltaic power still supplies power to the electric heater 5 to heat the pure water, and after heating, the pure water enters the phase change heat storage tank 53 to exchange heat with the phase change material, and the flow of the pure water is controlled by the flow control pump 75, so as to meet the temperature requirement of the pure water.

[0100] The third stage: when the photovoltaic power is completely not generated, the electric heater 5 stops working, the pure water enters the phase change heat storage tank 53 to exchange heat, so that the pure water meets the temperature requirement, if the pure water does not meet the temperature requirement of the electrolytic cell 6, the power grid supplies power to the electric heater 5, so as to meet the temperature requirement of the electrolytic cell 6.

[0101] The above is only a preferred embodiment of the present application, and is not used to limit the protection scope of the present application, therefore, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A pure water supply pipeline system for hydrogen production by water electrolysis, wherein the pure water supply pipeline system is equipped with a water replenishment pump (72), characterized in that: The pure water supply pipeline system is also equipped with a heat exchange pipeline, which exchanges heat between the water flowing before the water supply pump (72) and the water flowing after the water supply pump (72).

2. A pure water supply pipeline system for hydrogen production by water electrolysis, the pure water supply pipeline system comprising a pure water storage tank (1), an oxygen-water primary separator (2), an electrolytic cell (6), a first three-way valve (91) and a second three-way valve (92), the pure water supply pipeline system further comprising a waste discharge port and an oxygen outlet port; The outlet of the pure water storage tank (1) is connected to the main port of the first three-way valve (91), and the first switching port of the first three-way valve (91) is connected to the waste discharge port. The second switching port of the first three-way valve (91) is connected to the first switching port of the second three-way valve (92), and a water supply pump (72) is provided in the pipeline from the second switching port of the first three-way valve (91) to the first switching port of the second three-way valve (92); The main port of the second three-way valve (92) is connected to the oxygen water primary separator (2) through a pipeline, and the oxygen water primary separator (2) is then connected to the second conversion port of the second three-way valve (92) through another pipeline; The oxygen water primary separator (2) is connected to the inlet of the electrolytic cell (6) through a pipeline. An electrolytic cell circulation pump (74) is installed in the pipeline from the oxygen water primary separator (2) to the electrolytic cell (6). The anode side of the electrolytic cell (6) is connected to the oxygen water primary separator (2) through a pipeline. The oxygen-water primary separator (2) is connected to the oxygen outlet pipe; Its features are: The pure water supply pipeline system also includes a cooling water supply source (3), a first heat exchanger (81), and a second heat exchanger (82); A cooling water circulation pipeline is constructed based on the cooling water supply source (3). The first heat exchanger (81) is set between the pipeline at the outlet of the pure water storage tank (1) and the cooling water circulation pipeline. The second heat exchanger (82) is set between the pipeline connecting the main port of the second three-way valve (92) to the oxygen water primary separator (2) and the cooling water circulation pipeline. The water in the cooling water circulation pipeline is supplied by the cooling water supply source (3), and then passes through the second heat exchanger (82) and then the first heat exchanger (81).

3. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 2, characterized in that: A deionizer (4) and an electric heater (5) are sequentially installed in the pipeline connecting the main port of the second three-way valve (92) to the oxygen water primary separator (2). A deionization circulation pump (73) is installed in the pipeline from the oxygen water primary separator (2) to the second conversion port of the second three-way valve (92).

4. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 3, characterized in that: The electric heater (5) is powered by a photovoltaic panel (51).

5. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 2, characterized in that: The pure water supply pipeline system also includes a third heat exchanger (83), which is located between the pipeline connected to the waste discharge port and the pipeline connected to the oxygen outlet port.

6. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 2, characterized in that: The pure water storage tank (1) receives hydrogen-side return water.

7. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 2, characterized in that: The pure water storage tank (1) is equipped with a conductivity sensor, and the first three-way valve (91) is controlled by the conductivity sensor.

8. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 7, characterized in that: When the conductivity of the pure water in the pure water storage tank (1) is >0.2μS / cm, the first three-way valve (91) turns to the first conversion port and is connected to the waste discharge port through the pipeline until the conductivity of the pure water in the pure water storage tank (1) is <0.15μS / cm, at which point the first three-way valve (91) turns to the second conversion port.

9. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 2, characterized in that: A wastewater storage tank (11) and a heat exchange pump (71) are sequentially installed in the pipeline from the first switching port of the first three-way valve (91) to the waste discharge port.

10. The pure water supply pipeline system for hydrogen production by water electrolysis according to claim 3, characterized in that: The pure water supply pipeline system also includes an electric heating rod (52), a phase change heat storage tank (53), a flow control pump (75), a third three-way valve (93), and a fourth three-way valve (94); The first switching port of the third three-way valve (93) is connected to the oxygen water primary separator (2), and the electric heater (5) is located in the pipeline from the first switching port of the third three-way valve (93) to the oxygen water primary separator (2); The second switching port of the third three-way valve (93) is connected to the fourth three-way valve (94) through a pipeline. A flow control pump (75) and a phase change heat storage tank (53) are sequentially installed in the pipeline from the second switching port of the first three-way valve (91) to the fourth three-way valve (94). The phase change heat storage tank (53) is located on the outlet side of the flow control pump (75). The first switching port of the fourth three-way valve (94) is connected to the oxygen-water primary separator (2) through a pipeline, and the second switching port of the fourth three-way valve (94) is connected to the electric heater (5) through a pipeline.

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