50~200 Nm³/h Containerized PEM Electrolyzer

1、Circulating water supply unit

The power source of water circulation is a circulating water pump, and the circulating water supply unit is a closed water circulation. The inlet of the water pump is connected with the water tank; The outlet water flows into the electrolytic cell after being filtered by the filtering device. Oxygen generated by electrolysis carries part of water out of the anode outlet of the electrolytic cell and is discharged into the water tank.

The circulating water filtering device includes Y-type filter, deionized resin tank, filter and other hardware. The filter mainly absorbs impurities in the water circulation loop to prevent damage to the electrolyzer to be tested;

The water circulation loop is also equipped with cooling plate exchange and cooling plate exchange, which are mainly used to absorb excess heat in the operation of the electrolytic cell;

When the signal that the water conductivity in the circulating water unit exceeds the standard is detected (the alarm threshold can be set in the software), the circuit of the deionized resin tank can be automatically opened to automatically reduce the water conductivity online;

2、Deionized water supply unit

PEM electrolyzer consumes water all the time during operation, so it is necessary to make up water for closed water circulation unit in real time and online. The electrolyzer operates in a high-pressure environment, so the outlet pressure of the makeup pump needs to be higher than the working pressure to complete the makeup action.

The water replenishment circuit also needs to ensure the cleanliness of the water replenished into the system, so a filter and a check valve are arranged in the water replenishment circuit.

Components such as. During the water replenishment process, it is also necessary to ensure that the added fresh water (whose temperature is lower than the water temperature of the closed cycle in the operation condition) has the least impact on the test condition, so the method of "frequent water replenishment and small single water replenishment" is adopted.

3、Gas-liquid separation and gas condensation unit

During the operation of the electrolyzer, the hydrogen produced by the cathode and a small amount of water enter the cooling and condensing tube heat exchanger at the same time, and the cold water at 7~10℃ is introduced into the cold water side of the tube heat exchanger, and the gas flows through the condensing plate to continuously generate condensed water, and then enters the dryer. After the gas enters the dryer, the temperature drops to 12~15℃.

The gas enters the first-stage gas-water separator after passing through the tube heat exchanger, and the water and gas are separated efficiently in the first-stage steam-water separator (the separation efficiency is higher than 99%). The water is discharged from the lower part of the first-stage separator, and the gas continues to be transported to the next process at the upper part of the separator.

4、Back pressure control unit

After the gas flows out of the dryer, it flows through the back pressure control valve. By adjusting the opening of the back pressure valve, the pressure of the cathode or anode close system of the electrolytic cell can be adjusted. The back pressure adjustment range in this system is wide (0.5~ 3.5MPa), so it is necessary to use multiple valves in parallel to meet the demand of such a large valve adjustable ratio.

5、Unit voltage inspection unit (optional)

In order to monitor the performance of the electrolyzer in the whole operation process, the hydrogen production system is equipped with a single voltage acquisition unit, which can expand the sampling channel through multiple modules.

6、PLC sampling and control unit

Siemens S7-200 SMART controller is adopted to realize the collection of all monitoring variables and the functional operation control of the system, including control program module, digital/signal acquisition module, digital/signal output control module and communication data interaction module.

7、Sampling and control unit

It realizes the collection of various monitoring quantities of the system and the functional operation control of the system, including control host module, digital/signal acquisition module, digital/signal output control module, communication data interaction module and so on.

8、Safety protection unit

Hydrogen production system has the function of emergency stop. In case of unexpected situations, such as fire inside the bench, control interface of upper computer stuck, communication line broken or falling off, hydrogen overpressure or serious leakage, etc., the emergency stop function can be applied when personnel cannot handle it or have no processing time. Emergency stop includes hardware (emergency stop button) and software function (emergency stop button of control interface). Hydrogen production equipment has real-time display functions such as hydrogen pressure and waterway pressure, and has overpressure alarm function, which can be used according to overpressure conditions.

Take certain protection functions, such as automatic pressure relief, emergency cut-off and other protection functions.

In order to ensure the safety of hydrogen, a hydrogen sensor is designed and installed on the hydrogen production system. In case of hydrogen leakage, the controller program can make timely treatment according to the leakage amount to reach the set dangerous value range, directly turn off the power supply, cut off the water supply at the same time, open the exhaust valve, and enter the emergency stop program. Because the safety of hydrogen is particularly important, a special alarm lamp is designed at the top of the hydrogen production system. When there is hydrogen leakage, the alarm lamp can give a warning to remind the operator to enter the corresponding treatment program immediately according to the operating procedures.

For some unexpected situations, such as gas leakage, abnormal state of electrolytic cell and other faults, the change of monitoring parameters may be later than the operator's perception. The operator can press the emergency switch, and the system will immediately deal with some key valve parts directly through the circuit, cut off the power supply, open the exhaust valve and release the pressure automatically, and send the emergency switch state signal to the controller. After receiving the signal, the controller will immediately execute the fault handling procedure to ensure the safety of batteries, equipment and personnel.

The system has a safety PLC design, which can be put into use when the main control PLC fails in extreme cases, and the shutdown procedure is executed to ensure the safety of the hydrogen production system and the tested parts. The fault code is displayed on the upper computer interface, and the system can also be linked with the laboratory safety protection system through communication or I/O port.