在冷干機中，換熱器（蒸發(fā)器和預(yù)冷器）負荷可通過計算熱流體進出口焓差來求得：

In a cold dryer, the load of the heat exchanger (evaporator and precooler) can be calculated by calculating the enthalpy difference between the inlet and outlet of the thermal fluid.

 

Δh=1.01Δt+（2501+1.84Δt）Δd （KJ/kg干空氣） ①

Delta h=1.01 Delta t+ (2501+1.84 delta T) Delta D (KJ/kg dry air)

 

式中Δt──作為熱流體的壓縮空氣進出口溫度差，℃

In the form of delta T - the temperature difference between the inlet and outlet of the compressed air as a thermal fluid, C

 

Δt=t’-t”

Delta t=t '-t

t’──壓縮空氣進入換熱器時的溫度

T '-- the temperature of compressed air entering the heat exchanger

 

t”──壓縮空氣離開換熱器時的溫度

T "- the temperature of compressed air leaving the heat exchanger

 

1.01──干空氣的平均定壓比熱，KJ/kg.℃

1.01 - average constant pressure and specific heat of dry air, KJ/kg. C

 

1.84──水蒸氣的平均定壓比熱，KJ/kg.℃

1.84 - the average constant pressure of water vapor, KJ/kg. C

 

2501──水的汽化潛熱，KJ/kg

2501 - latent heat of vaporization of water, KJ/kg

 

Δd ──換熱器中產(chǎn)生的凝結(jié)水量，kg

Delta D - condensation water produced in the heat exchanger, kg

 

Δd=d’-d”

Delta d=d '-d

 

式中，d’、d”分別表示對應(yīng)溫度t’和t”時壓縮空氣中的飽和含水量，kg。

In the formula, d 'and D respectively indicate the saturated water content in the compressed air, kg, when the temperature T' and T are corresponding to the temperature.

 

換熱器的熱負荷為

The heat load of the heat exchanger is

 

Q=qmΔh （W） ②

Q=qm delta H (W) 2

 

式中，qm──空氣的質(zhì)量流量，kg/s

In the formula, QM - the mass flow of air, kg/s

 

公式①和②是計算壓縮空氣降溫過程熱負荷的基本公式，它由下述三部分組成：

The formula 1 and 2 are the basic formulas for calculating the heat load of the compressed air cooling process. It consists of the following three parts:

 

1）1kg干空氣從t’降到t”放出的熱量1.01Δt；

1) the heat of 1kg dry air from t 'to t' is 1.01 delta T;

 

2）（d’-d”）kg的水蒸氣從t’降到t”放出的熱量；

2) the heat released from the water vapor from t 'to t in (d' -d ") kg.

 

3）（d’-d”）kg的水蒸氣凝結(jié)成液態(tài)水放出的凝聚熱（在數(shù)值上等于汽化潛熱）。

3) (d '-d ") the condensation heat of the water vapour of kg condenses into liquid water (in numerical value equals vaporization latent heat).

 

其中1），2）兩項是隨溫度變化的熱量，稱為顯熱，第3）項由凝結(jié)水量的多少決定，它不參與系統(tǒng)的換熱，因此是潛熱。

Among them, 1), 2) two is the heat that changes with the temperature. It is called sensible heat. Third) is determined by the amount of condensation water. It does not participate in the heat exchange of the system, so it is latent heat.

 

在蒸發(fā)器里，冷媒蒸發(fā)過程放出的冷量（或吸收的熱量），一部分用于壓縮空氣的降溫，另一部分用于支付水蒸氣凝結(jié)所需的潛熱；

In evaporator, the cooling capacity (or absorbed heat) released by the refrigerant evaporation process is used for cooling the compressed air, and the other part is used to cover the latent heat required for steam condensation.

 

在預(yù)冷器里，低溫干燥空氣升溫過程吸收的熱量（或放出的冷量）一部分用于壓縮空氣進氣的降溫，另一部分用來支付熱氣流中部分水蒸氣凝結(jié)所需的潛熱。

In the pre cooler, the amount of heat absorbed (or released) during the heating process of low temperature and dry air is partly used for cooling the compressed air intake, and the other part is used to cover the latent heat required for condensation of some steam in the hot gas flow.

 

結(jié)合上圖，通過單位質(zhì)量流量（kg/s）壓縮空氣時，預(yù)冷器熱負荷可以寫成

Combined with the above picture, the heat load of the precooler can be written when the unit mass flow (kg/s) is compressed into the air.

 

Q’=[1.01Δt1-2+（2501+1.84Δt1-2）*（d1-d2）] （W）

Q '=[1.01 Delta t1-2+ (2501+1.84 delta T1-2) * (d1-d2)] (W)

 

式中，Δt1-2=t1-t2

In the formula, Delta t1-2=t1-t2

 

通過單位質(zhì)量流量（kg/s）壓縮空氣時，蒸發(fā)器熱負荷可寫成如下表達式

When the air is compressed by a unit mass flow (kg/s), the heat load of the evaporator can be written as the following expression

 

Q0=[1.01Δt2-3+（2501+1.84Δt2-3）*（d2-d3）] （W）

Q0=[1.01 Delta t2-3+ (2501+1.84 Delta T2-3) * (d2-d3)] (W)

 

式中，Δt2-3=t2-t3

In the formula, Delta t2-3=t2-t3