Water replenishing device of water electrolysis system

Abstract

The utility model discloses a water replenishing device of an electrolyzed water system, which comprises a separator for gas-liquid separation, a transition pipe for leading in replenishing water is arranged at the top of the separator, a heat exchange pipe is arranged in the separator, an outlet of the heat exchange pipe is communicated with an inlet of the transition pipe, and a delivery pump is arranged at the inlet of the transition pipe. According to the scheme, the heat exchange tube is arranged in the separator, so that on one hand, a relatively small amount of make-up water enters the separator and is fully preheated, and the temperature of an inlet of the electrolytic bath is maintained at about 70-75 DEG C; on the other hand, the preheated make-up water is conveyed to the uppermost portion of the gas-liquid separator through the transition pipe and injected into the gas-liquid separator, gas washing is carried out, secondary heating is carried out through gas pre-waste heat, the alkaline solute is recycled, and meanwhile heat is fully utilized.

Description

Technical Field

[0001] The utility model relates to a water replenishing device for an electrolytic water system and belongs to the field of electrolytic water devices. Background Art

[0002] Alkaline water electrolysis is a process that consumes electricity and water to produce hydrogen and oxygen. Pure water is continuously added during the electrolysis process. The temperature of the electrolyte is around 80-90°C, and the supplementary water is room temperature water (1-30°C). It is directly added. The large temperature difference between the inlet and outlet of the electrolytic cell can easily cause temperature turbulence and voltage instability, affecting the electrolysis process. The electrolyte is alkaline solution, and the gas formed by electrolysis contains a large amount of alkali when it is separated from the alkaline solution. As the electrolysis process proceeds, the alkaline solute in the electrolyte decreases.

[0003] In the prior art, in order to simultaneously solve the problems of the temperature of the supplementary water and the reduction of the alkaline solutes in the electrolyte, the invention patent application with the publication number CN 104388971A discloses a comprehensive treatment device for water electrolysis hydrogen production equipment, in which a gas outlet tank body of the gas-liquid separator is provided with a sleeved gas return pipe and an overflow pipe inside the tank body, and a cooling water coil is also provided outside the gas return pipe. An interlayer is formed between the gas return pipe and the tank body to temporarily store the supplementary water, and the gas enters the bottom of the interlayer through the gas return pipe to preheat the supplementary water and wash away the alkali in the gas. The preheated supplementary water containing alkali enters the separator through the overflow pipe and finally flows into the electrolytic cell, the water consumed in the electrolyte, and the alkali is recovered. This solution solves the preheating and gas washing at the same time, but adds additional devices, a complex structure, and increased costs. The utility model patent application with publication number CN 204874762 U discloses an electrolyte liquid adding circulation cooling system. By setting a replenishment tank and a power mechanism, a cooling coil is set inside the replenishment tank. The power mechanism introduces the electrolyte with too high temperature into the cooling coil, and performs heat exchange with the supplementary water pre-stored in the replenishment tank, so that the temperature of the supplementary water increases and the temperature of the electrolyte decreases. The electrolyte refluxes after cooling, and the supplementary water after heating is used to replenish the water consumed in the electrolysis process to maintain the reaction. The amount of supplementary water is small compared to the electrolyte. The degree of reduction in electrolyte temperature in this scheme depends on the size of the replenishment tank. When the replenishment tank is large, the electrolyte will be too low in temperature after heat exchange. When the replenishment tank is small, a large amount of electrolyte is continuously drawn out for heat exchange with the supplementary water, which easily causes the supplementary water to overheat or even boil. The practical application is limited, and the problem of reduced alkaline solutes in the electrolyte cannot be solved at the same time. Utility Model Content

[0004] Purpose of the utility model: The purpose of the utility model is to provide a water replenishing device for an electrolytic water system which has a simple structure and can preheat replenished water and recover alkali.

[0005] Technical solution: The utility model describes a water replenishment device for an electrolyzed water system, comprising a separator for gas-liquid separation, a transition pipe for introducing replenishing water is provided on the top of the separator, a heat exchange pipe is provided inside the separator, the heat exchange pipe outlet extends out of the separator and is connected to the transition pipe inlet, and a delivery pump is provided at the heat exchange inlet.

[0006] The separator is used to separate the residual gas in the electrolyte after electrolysis. The electrolyte inside the separator is large in volume and high in temperature. This solution sets the heat exchange tube inside the separator. On the one hand, a relatively small amount of supplementary water enters the separator and is fully preheated, so that the inlet temperature of the electrolytic cell is maintained at about 70-75°C; on the other hand, the preheated supplementary water is transported to the top of the gas-liquid separator through the transition pipe and injected into the gas-liquid separator to wash the gas and be heated again by the preheated waste heat of the gas, recovering the alkaline solute while making full use of the heat.

[0007] In addition, a relatively small amount of make-up water enters the gas-liquid separator. Even if the heat exchange tube is damaged, it will not cause a large fluctuation in the electrolyte concentration, which helps to maintain the stability of the electrolysis process.

[0008] Preferably, in order to fully utilize the heat, the transition pipe outlet is arranged above the wire mesh demister of the gas-liquid separator.

[0009] Preferably, in order to allow the supplementary water to fully contact with the separated gas, a nozzle or a distribution plate is provided at the transition pipe outlet.

[0010] Preferably, in order to facilitate assembly and prevent device failure from affecting the electrolysis process, the heat exchange tube and the transition tube, and the heat exchange tube and the delivery pump are connected by flange connectors. If the heat exchange tube fails, the outlet of the water supply pump can be directly connected to the inlet of the transition tube through a flange, so as to maintain the electrolysis process and avoid downtime for maintenance during the electrolysis process. In addition, the use of an external transition tube to support and fix the heat exchange tube inside the separator makes the overall device assembly simpler.

[0011] Preferably, in order to facilitate installation and fixation of the transition pipe, the transition pipe and the separator are connected via a flange connector.

[0012] Preferably, a lead-out pipe for connecting to the electrolytic cell is provided at the bottom of the gas-liquid separator.

[0013] Preferably, the heat exchange tube is spiral or W-shaped.

[0014] Beneficial effects: Compared with the prior art, the utility model has the following advantages: 1. Fully preheating the supplementary water to maintain the inlet and outlet temperature of the electrolytic cell stable, while collecting the alkaline solutes entrained by the gas; 2. Simple structure, easy to install and maintain; 3. Maintaining continuous electrolysis of water. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the working state structure of the first embodiment of the utility model;

[0016] Figure 2 This is a schematic diagram of the emergency state structure of the first embodiment of the utility model;

[0017] Figure 3 This is a schematic diagram of the working state structure of the second embodiment of the utility model;

[0018] Figure 4 This is a schematic diagram of the emergency state structure of the second embodiment of the utility model. DETAILED DESCRIPTION

[0019] The technical solution of the utility model is further described below in conjunction with the accompanying drawings.

[0020] Example 1: Figure 1 and Figure 2 As shown, the utility model discloses a water replenishing device for an electrolytic water system, which consists of a separator 1, a heat exchange tube 2 and a transition tube 3, wherein the separator 1 is a vertical gas-liquid separator for separating the gas inside the electrolyte after electrolysis, and a wire mesh demister (not shown) is provided on the top thereof. The separator 1 is a prior art and will not be described in detail here.

[0021] After the electrolyzed electrolyte is separated by the separator 1, the inside of the separator 1 can be roughly divided into two phase regions, gas and liquid. The transition pipe 3 is roughly arranged outside the gas phase region of the separator 1, and is used to introduce supplementary water into the separator 1. The supplementary water contacts the gas above the separator 1 through spraying, washes the gas and recovers the alkali entrained in the gas. The heat exchange tube 2 is roughly arranged in the liquid phase region inside the separator 1, and is used to exchange heat between the supplementary water and the electrolyte. The top outlet of the heat exchange tube 2 is connected to the bottom inlet of the transition tube 3, and the bottom inlet of the heat exchange tube 2 is connected to the delivery pump 4 for delivering the supplementary water. The heat exchange tube 2 guides the supplementary water into the separator 1, so that the supplementary water and the electrolyte inside the separator 1 are heat exchanged, and then injected into the separator 1 through the transition tube 3. The shape of the tube body of the transition tube 2 is determined according to the heat exchange requirements, and can be spiral or other shapes. The bottom of the separator 1 is provided with a lead-out pipe 6 for connecting to the electrolytic cell.

[0022] The top outlet of the transition pipe 3 is arranged above the wire mesh demister (not shown), and the supplementary water is guided through the transition pipe 3 to bypass the gas phase zone of the separator 1 and enter the separator 1 from the top of the gas phase zone to remove the residual alkali in the gas, cool the gas, and heat the supplementary water again. A nozzle or a distribution plate can be arranged at the top outlet of the transition pipe 3 to disperse the supplementary water and increase the water-gas contact area. Since the top outlet of the transition pipe 3 is arranged at the top of the separator 1, the supplementary water is at a certain distance from the inlet of the electrolytic cell, and the fluctuation caused is small.

[0023] The top outlet of the transition pipe 3 and the separator 1, the transition pipe 3 and the heat exchange pipe 2, and the heat exchange pipe 2 and the delivery pump 4 are all connected by flange connectors 5. The heat exchange pipe 2 is not easy to fix inside the gas-liquid separator 1, but the transition pipe 3 is easy to fix outside the separator 1. The heat exchange pipe 2 is fixed by the transition pipe 3, which is convenient for installation.

[0024] The heat exchange tube 2 is connected to the delivery pump 4 and the transition pipe 3 through the flange connector 5. When the heat exchange tube 2 is damaged due to electrolyte corrosion, the water replenishment position changes, and the thermal management system of the electrolyzer will send a signal to the control of the water replenishment device to shut down the water replenishment device, affecting the electrolysis process. In order to prevent the water replenishment process from stopping due to the damage of the heat exchange tube 2, when the heat exchange tube 2 is damaged, such as Figure 2 The delivery pump 4 can pass over the heat exchange tube 2 and be directly connected to the transition tube 3 through the flange connector 5 to maintain the electrolysis process. After the electrolysis is completed, the machine can be shut down for maintenance.

[0025] 1000m 3 / h electrolytic cell, the total amount of electrolyte is 25-28t, and the average hourly replenishment amount is 1t. With this device, the replenishment water can be preheated to 70-75℃, greatly reducing the inlet and outlet temperature difference of the electrolytic cell. The replenishment water volume is less than the electrolyte volume. Even if the heat exchange tube 2 is damaged at a long distance and the temperature fluctuation is not detected in time, it will not cause a sharp change in the electrolyte concentration in a short time, which helps to maintain the stability of the electrolysis process.

[0026] Example 2: Figure 3 and Figure 4 As shown, this embodiment is consistent with Embodiment 1, and is also composed of a gas-liquid separator 1, a heat exchange tube 2 and a transition tube 3. The difference is that the separator 1 of this embodiment is a horizontal gas-liquid separator, most of the main body of the heat exchange tube 2 is arranged in the liquid phase area inside the gas-liquid separator 1, a small part is arranged in the liquid phase area, and the transition tube 3 is arranged at one end away from the bottom inlet of the heat exchange tube 2.

Claims

1. A water replenishing device for an electrolytic water system, comprising a separator (1) for gas-liquid separation, characterized in that: A transition pipe (3) for introducing supplementary water is provided at the top of the separator (1), a heat exchange pipe (2) is provided inside the separator (1), the outlet of the heat exchange pipe (2) is connected to the inlet of the transition pipe (3), and a delivery pump (4) is provided at the inlet.

2. The water replenishing device for electrolyzed water system according to claim 1, characterized in that: The outlet of the transition pipe (3) is arranged above the wire mesh demister of the separator (1).

3. The water replenishing device for electrolyzed water system according to claim 2, characterized in that: The outlet of the transition pipe (3) is provided with a nozzle or a distribution plate.

4. The water replenishing device for electrolyzed water system according to claim 1, characterized in that: The heat exchange tube (2) and the transition tube (3), and the heat exchange tube (2) and the delivery pump (4) are connected via flange connectors (5).

5. The water replenishing device for electrolyzed water system according to claim 2, characterized in that: The transition pipe (3) and the separator (1) are connected via a flange connection (5).

6. The water replenishing device for electrolyzed water system according to claim 1, characterized in that: The bottom of the separator (1) is provided with an outlet pipe (6) for connecting to the electrolytic cell.

7. The water replenishing device for electrolyzed water system according to claim 1, characterized in that: The heat exchange tube (2) is spiral-shaped or W-shaped.

Images