電解車壓差控制-中英對照
電解車間壓差控制

通常，電解車間中的壓差總體的控制，是通過對共同電解車間排出管上游氯氣和氫冷卻的工作壓強(qiáng)和差壓的測量來進(jìn)行。對一個有下游氯氣和

干燥管的電解車間來說，最簡單人們最會傾向于采取的控制策略包括將氯作為主工作壓強(qiáng)控制器，同時通過一個壓差控制器將氫排出到大氣中

，以此同時來控制氫壓強(qiáng)。

電解車間壓差控制器內(nèi)的設(shè)定值必須時刻保持在氫大于氯15mbar，控制系統(tǒng)應(yīng)起調(diào)節(jié)作用，這樣在穩(wěn)態(tài)運行狀態(tài)下，壓差的波動相對于設(shè)定值

不會超過正負(fù)3mbar。但是，必須避免離子膜震顫的發(fā)生，由于控制系統(tǒng)過于敏感， 它會引起離子膜和網(wǎng)眼之間的摩擦損害。

對于偏差和脫扣運行來說，測量到的差數(shù)波動性增大是可以允許的，壓差控制系統(tǒng)必須設(shè)計成在所有可能的分離帶來的干擾下，比如整流器脫

扣，壓差不會超過氫大于氯-10到+40mbar的范圍，一旦超出這個范圍，無論超出時間多段，都會對離子膜和電解組件造成不可修復(fù)的損害。

至關(guān)重要的一點是，要充分考慮到壓差測量設(shè)備的可靠程度和系統(tǒng)中建立冗余的潛在需求。

4.6.2局部電解壓差控制

對于裝載超過一個BICHLORTM 電解槽的電解車間來說，關(guān)鍵是壓強(qiáng)和差壓控制器要在一臺BICHLORTM 電解槽和另一臺BICHLORTM 電解槽的開車

和停車要分開。控制器營控制電解槽局部支流的排出，當(dāng)通往主總管的氣體隔離閥關(guān)閉后，通過極化并凈化氣體形成氯吸收（氯氣）和大氣排

放（氫氣）。

局部壓差控制器的設(shè)定值必須在氫大于氯10-15mbar之間，控制系統(tǒng)應(yīng)起調(diào)節(jié)作用，在穩(wěn)定開車或停車狀態(tài)下，壓差的波動相對于設(shè)定值不會超

過正負(fù)3mbar�？刂葡到y(tǒng)應(yīng)設(shè)計為，當(dāng)開車和停車運行時，在所有可能的瞬間突發(fā)狀況發(fā)生時，壓差不會超過氫大于氯0到+30mbar的范圍。

系統(tǒng)大小須滿足開車和停車時所有無用雜料的凈化要求，同時適用于極化階段產(chǎn)生氣體。盡管如此，若在一臺電解槽的開車和停車階段，需要

防止凈化氣體進(jìn)入主總管，那么可能需要調(diào)整系統(tǒng)尺寸，滿足等值于1千安/m2。同時系統(tǒng)必須可調(diào)試，這樣壓強(qiáng)就能順利地在大氣壓強(qiáng)和電解

車間運作壓強(qiáng)之間提高或降低，并使得壓差一直處于上述定義的控制區(qū)間內(nèi)。
4.6 Differential Pressure Control
4.6.1 Cellroom Differential Pressure Control

Differential pressure is normally controlled on the cellroom as a whole from measurements of working pressure and differential pressure at the common cellroom outlet headers upstream of chlorine and hydrogen cooling. For a typical cellroom with downstream chlorine cooling and drying train, the simplest preferred control scheme involves using chlorine as the master working pressure controller with hydrogen pressure following this via a differential pressure controller that vents hydrogen to atmosphere.

The cellroom differential pressure controller must operate at all times with a set point of 15 mbars hydrogen over chlorine. The control systems should be tuned, such that under steady state operating conditions, the fluctuation in differential pressure around the set point does not exceed +/- 3 mbar.
However, what must be avoided is membrane ‘flutter’ due to an oversensitive control system, which can cause abrasive damage of membranes against the meshes.

For operating excursions, trips etc greater fluctuations in measured differential are permissible. The differential pressure control system must be designed such that under all conceivable operating excursions from disturbances such as rectifier trips, the differential pressure never goes outside the range of –10 to + 40 mbars hydrogen over chlorine. Any departure from this range, however short in duration, could result in irreversible damage to membrane and Electrolyser components.

It is essential that full consideration is given to the reliability of differential pressure measurement instruments and the potential requirement for building redundancy into this system.    

4.6.2 Local Electrolyser Differential Pressure Control

For cellrooms containing more than one BICHLORTM Electrolyser, it is essential that pressure and differential pressure controllers are provided to permit start-up and shutdown of an Electrolyser independently from other Electrolysers in the cellroom. The controllers will control local sidestream vents from the Electrolyser, which will pass polarisation and purge gases into chlorine absorption (for chlorine) and atmosphere (for hydrogen), when the isolation valves to the main gas headers are closed. 

The set point for the local differential pressure controllers must be 10-15 mbars hydrogen over chlorine. The control systems should be tuned, such that under steady start-up / shutdown conditions, the fluctuation in differential pressure around the set point does not exceed +/- 3 mbar. The control system must be designed such that under all conceivable transient events during start-up and shut-down operations, differential pressure never goes outside the range of 0 to + 30 mbars, hydrogen over chlorine.

These systems must be sized for full inerts purge requirements at start-up and shutdown, and for gases generated during polarisation. However, it may be necessary to size them for process gas flows up to the equivalent of 1 kA/m2 if there is a requirement to prevent purge gases entering the main gas headers during start-up and shut-down of a single electrolyser. They must also be set-up so that pressure can be smoothly raised and lowered between atmospheric and cellroom operating pressure, with differential pressure always within the control envelope defined above.

 2014.8.22