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水电解制氢工作原理
Water electrolysis hydrogen works
水电解制氢是一种较为方便的方法。在充满氢氧化钾的电解槽中通入直流电，水分子在电极上发生电化学反应，分解成氢气和氧气。其化学反应式如下 ：
阴 极：2H2O+2e H2↑ +2OH
阳 极： 2OH—2e H2O+1/2O2↑
总反应式：2H2O 2 H2↑+ O2↑
根据库仑定律，气体产量与电流成正比，与其它因素无关。氢氧化钾的作用在于增加水的电导，本身不参加电解反应，理论上是不消耗的。电解液中加入五氧化二矾的作用是在于降低电解电压。单位气体产量的电耗，取决于电解电压，电解槽的工作温度越高，电解电压越低，同时也增加了对电解槽材料，主要是隔膜材料的腐蚀。石棉在碱液中长期使用温度不能超过100℃，因此操作温度选择在80~85℃为宜。电解压力的选择主要根据用氢的需要。气体纯度决定于制氢机结构和操作情况。在设备完好操作压力正常的条件下，纯度是稳定的。
工艺流程简介
生活自来水经纯水装置处理制取纯水，并送入原料水箱，经补水泵输入碱液系统，补充被电解消耗的水。电解槽中的水，在直流电的作用下被分解成H2与O2，并与循环电解液一起分别进入框架中的氢、氧分离洗涤器后进行气液分离、洗涤、冷却。分离后的电解液与补充的纯水混合后，经碱液冷却器、碱液循环泵、过滤器送回电解槽循环，电解。调节碱液冷却器冷却水流量，控制回流碱液的温度，来控制电解槽的工作温度，使系统安全运行。分离后的氢气由调节阀控制输出，经氢气纯化装置纯化后，送入氢气储罐，再经缓冲减压后，供用户使用。
主要设计条件：
1、 原料水（电解用水）：
要求：二次蒸馏水（或去离子水），电阻率＞2.0×105Ω٭cm；氯离子含量＜2mg/l；悬浮物＜lmg/l，按实际经验，原料水设备能力应为2—8小时产量供水电解24小时使用量。
2、 电解液：26%KOH水溶液
3、 控制柜电源：
三相四线制AC
设备控制系统
1 测点设置：系统测点设置齐全，影响系统安全稳定运行的量均设置了上限或下限。除系统中的常规控制测点外，仪用气源压力设置控制测点，自动操作阀设有阀位反馈，使系统在水、电、气都合格的情况下运行，保证了阀门及仪表动作的正确性和出现故障时提示并在影响系统安全运行时联锁停机，保障系统安全运行。
2 自动运行：系统只要具备开机条件，只需点击开车按钮，系统自动检测各参数的正确性，以最优值自动升压、升流，自动开启除盐水冷却装置，自动投运分析仪表，自动补水，系统全自动运行。氢气合格后自动充罐，罐压力到达定值时自动维持热备运行（小电流运行）或停车，停车后自动切断整流柜电源和工业冷却水，自动停运分析仪表。
3、安全性
3.1 冗余设计。特殊参数的监控采用各自独立的硬件回路，关系到系统的安全运行的回路采用冗余；
3.2 完善的联锁报警功能。与系统安全运行有关的参数均设置了报警和联锁功能，以保障系统安全运行，相应的调节上、下限，报警上、下限，联锁上、下限均可根据用户的需要进行在线调整。一旦系统发生超限联锁，则系统整流柜停机，且分阶段对系统进行安全降压，如果中途故障消除，则系统又会自动投入正常运行。
水电解设备主要部件：
电解槽
框架
整流变压器
整流柜
控制柜
原料水箱
原料碱箱
Water electrolysis hydrogen works
Water electrolysis hydrogen is a more convenient way. Full of potassium hydroxide into direct current through the electrolytic cell, an electrochemical reaction of water molecules on the electrode, into hydrogen and oxygen. The chemical reaction is as follows:
Cathode: 2H2O + 2e H2 ↑ + 2OH
Anode: 2OH-2e H2O + 1 / 2O2 ↑
Overall reaction: 2H2O 2 H2 ↑ + O2 ↑
According to Coulomb's law, proportional to the current gas production, independent of other factors. Role of potassium is to increase the conductivity of the water itself does not participate in the electrolytic reaction, it is not consumed in theory. Electrolyte vanadium pentoxide was added role is to reduce the electrolysis voltage. Electricity gas production unit of consumption, depending on the electrolysis voltage, the higher the cell operating temperature, the lower the electrolysis voltage, but also increased the cell material, mainly corrosion diaphragm material. Long-term use of asbestos in lye temperature should not exceed 100 ℃, so the operating temperature is selected is appropriate at 80 ~ 85 ℃. Select electrolysis pressure primarily on the basis of hydrogen needed. Hydrogen gas purity depends on the structure and operation of the machine. Under normal operating pressure equipment in good condition, purity is stable.
Process Description
Water means life through water treatment system of pure water, and raw materials into the water tank, the water supply pump input lye system, supplemented by electrolysis of water consumed. Cell water, under the action of a direct current is decomposed into H2 and O2, respectively, along with the electrolyte circulation into the framework of the hydrogen gas-liquid separation, washing, oxygen separator scrubber after cooling. After the separation of pure water mixed with an electrolyte supplement upon, lye cooler, lye circulation pump, filter back to the cell cycle, electrolysis. Lye cooler water flow regulator to control the temperature of reflux lye to control the operating temperature of the cell, to make the system safe operation. After the separation of hydrogen from the control valve output, after purification of hydrogen purification device, into the hydrogen tank, and then the buffer after decompression, for users.
The main design criteria:
1, raw water (electrolysis of water):
Requirements: double distilled water (or deionized water), the resistivity of> 2.0 × 105Ω * cm; chloride ion content of <2mg / l; suspension <lmg / l, according to practical experience, the water feed device capability should be 2-8 hours electrolysis of water yields 24 hours usage.
2, the electrolyte: 26% KOH solution
3, power control cabinet:
Three-phase four-wire AC
Equipment control system
1 measuring point: System measuring points set up complete, safe and stable operation of the system affect the volume set upper or lower limit. In addition to the conventional control system measuring point, set the control instrument with air pressure measuring points, automatically operated valve is provided with valve position feedback, the system is running in the water, electricity and gas are qualified, to ensure the operation of valves and instrumentation correct and prompt interlock failure and downtime affecting the safe operation of the system, the security system safe operation.
2 automatic operation: as long as the system is ready for start, just click the drive button, the system automatically detects the correctness of the parameters to optimal values automatically boost, flow automatically open demineralized water cooling device, automatic analytical instruments put into operation, automatic replenishment, the system fully automatic operation. After passing the hydrogen tank automatic filling, tank pressure reaches the set value is automatically maintained when running Hot Standby (low current operation) or stop, automatically cut off the power supply and rectifier cabinet industrial cooling water, parking, automatic shutdown of the instrument.
3, security
3.1 redundant design. Monitor specific parameters using separate hardware circuits, related to the safe operation of the loop system with redundant;
3.2 perfect interlock alarm. Parameters related to the safe operation of the system are set up alarm and interlock functions, to ensure safe operation, the corresponding adjustment of the lower limit, the alarm, the lower limit, the interlock, the lower limit can be adjusted according to the needs of users online. Once the interlock system overrun occurs, the system rectifier cabinet down and secure the system in stages down, if the failure to eliminate the middle, the system will automatically put into normal operation.
Water electrolysis apparatus main components:
Cell
frame
Rectifier transformer
Rectifier cabinet
Control cabinet
Raw water tank
Raw material base box
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