傳熱過(guò)程分析（熱工分析）是任何熱工設(shè)備設(shè)計(jì)和制作的理論依據(jù)。冷干機(jī)熱工計(jì)算的目的是根據(jù)壓縮空氣狀態(tài)（主要是進(jìn)氣壓力和溫度），確定其降溫過(guò)程制冷系統(tǒng)所需要供給的制冷量Q、預(yù)冷器和蒸發(fā)器的負(fù)荷分配、計(jì)算冷干機(jī)排水量，同時(shí)也可借此預(yù)測(cè)排氣干球溫度t4。

The analysis of heat transfer process (thermal analysis) is the theoretical basis for the design and manufacture of any thermal equipment. Cold and dry machine thermal calculation according to the compressed air condition (mainly inlet pressure and temperature), the cooling process of the refrigeration system to supply cooling capacity Q, pre cooler and evaporator load distribution calculation, cold and dry machine displacement, and also can be used to forecast the exhaust dry bulb temperature t4.

 

就其實(shí)質(zhì)而論，冷干機(jī)是由兩個(gè)換熱器構(gòu)成的復(fù)合式換熱器，共有三種不同狀態(tài)的流體參與了換熱：

As a matter of fact, the cold dryer is a compound heat exchanger consisting of two heat exchangers. There are three different states of fluid involved in the heat exchange.

①預(yù)冷器里，熱流體是溫度較高的飽和壓縮空氣，冷流體是冷卻后相對(duì)干燥的壓縮空氣，兩者水當(dāng)量（定壓比熱與質(zhì)量的乘積）極為接近；

(1) in the precooler, the hot fluid is a high temperature saturated compressed air, and the cold fluid is the relatively dry compressed air after cooling. The water equivalent of the two parts is very close to the product of constant pressure and specific heat.

 

②蒸發(fā)器里熱流體是溫度已預(yù)先降低了的飽和壓縮空氣，冷流體是冷媒蒸汽。

The thermal fluid in the evaporator is the saturated compressed air which has been reduced in advance by the temperature, and the cold fluid is the refrigerant steam.

 

蒸發(fā)器由獨(dú)立的制冷系統(tǒng)提供冷源，而預(yù)冷器的冷源則來(lái)自通過(guò)蒸發(fā)器冷卻了的壓縮空氣，因而不具備獨(dú)立性。所以說(shuō)，在整個(gè)熱交換過(guò)程中預(yù)冷器的作用是回收制冷系統(tǒng)產(chǎn)生的部分冷量，客觀上減少了整機(jī)的能量消耗。

The evaporator provides a cold source by an independent refrigeration system, while the cold source of the precooler comes from the compressed air cooled by the evaporator, and thus does not have independence. Therefore, in the whole process of heat exchange, the function of the precooler is to recover part of the cooling capacity produced by the refrigeration system and reduce the energy consumption of the whole machine.