1、 Function of biogas engine coolant

沼氣發動機正常工作溫度為65-70°，比普通的發動機要低15-20°，過高的發動機溫度會使混合氣體爆燃，影響發動機正常運轉同時會加速發動機油蛻變，使之產生積碳，容易形成油膜決裂，光滑不良，磨損加劇。因而，運用發動機冷卻液對沼氣發動機停止恰當降溫尤為重要，能夠保證發動機正常工作。

The normal working temperature of biogas engine is 65-70 °, which is 15-20 ° lower than that of ordinary engine. Too high engine temperature will deflagration the mixed gas, affect the normal operation of the engine, and accelerate the transformation of engine oil to produce carbon deposition, which is easy to form oil film cracking, poor smoothness and intensified wear. Therefore, it is particularly important to use engine coolant to stop and properly cool the biogas engine, which can ensure the normal operation of the engine.

但假如發動機的溫度太低，冷卻過度，也會產生反作用，使發動機蓋的熱量損失加大，不利于可燃混合氣體的構成和熄滅，并招致發動機油粘度變大，摩擦損失增加，形成發動機有效功率降低。

However, if the temperature of the engine is too low and the cooling is too excessive, it will also have a reaction, which will increase the heat loss of the engine cover, which is not conducive to the composition and extinction of combustible gas mixture, increase the viscosity of engine oil, increase the friction loss, and reduce the effective power of the engine.

在實踐運用過程中，普通應用冷卻液的小循環和大循環處理沼氣發動機的冷卻光滑問題， 使發動機得到適度的冷卻，從而使其堅持在適合的溫度范圍內工作。通常關于沼氣發動機的水冷卻系統，當缸蓋冷卻水套中的冷卻液溫度到達60°左右時，大循環啟動，可確保沼氣發動機正常工作。

In the process of practical application, the small cycle and large cycle of coolant are commonly used to deal with the problem of smooth cooling of biogas engine, so that the engine can be moderately cooled, so as to make it work within the appropriate temperature range. Generally, for the water cooling system of biogas engine, when the coolant temperature in the cylinder head cooling water jacket reaches about 60 °, the large cycle is started to ensure the normal operation of biogas engine.

二、水介質能否能替代發動機冷卻液

2、 Can water replace engine coolant

在實踐運用中用戶常常疏忽發動機冷卻液的運用，而簡單的用水作為發電機組的冷卻介質。隨著發電機組的運轉冷卻水損耗嚴重，需求頻繁補加水分，且運用一段時間后就會結垢，招致發電機組冷卻效果降落，發動機運轉溫度升高，影響發電機組的正常發電。

In practice, users often neglect the use of engine coolant, and simply use water as the cooling medium of generator set. With the operation of the generator set, the cooling water loss is serious, the water needs to be added frequently, and scaling will occur after use for a period of time, resulting in the reduction of the cooling effect of the generator set and the increase of the engine operating temperature, affecting the normal power generation of the generator set.