How To Calculate Plate Type Heat Exchanger

How To Calculate Plate Type Heat Exchanger

   The plate heat exchanger is a new type of high-efficiency heat exchanger formed by stacking a series of metal plates with a certain corrugated shape. A thin rectangular channel is formed between the various plates to exchange heat through the plate. Compared with the conventional shell-and-tube heat exchanger, the heat transfer coefficient is much higher under the same flow resistance and pump power consumption, and there is a tendency to replace the shell-and-tube heat exchanger within the applicable range.


Hot side- 65M3/H, Inlet :90 ℃,Outlet:45℃,Cold side-58.5M3/H Inlet:25℃,Outlet:75℃,Pressure:100Kpa

 physical parameters

Hot fluid: Density(ρ1)=979.1kg/m3   Specific heat(cp1)=4.185KJ(kg. ℃)

Cold fluid: Density(ρ1)=988.1kg/m3   Specific heat(cp1)=4.174KJ(kg. ℃)

Design process

1. Heat load (Q)=qm1 .cp1(t1’- t1”)=(65/3600)x979.1x4.185x(90-45)=3329.25Kw

2. Logarithmic mean temperature difference
Tm=T1-T2÷㏑(T1/T2)=(20-15) ÷(20/15)=17.38℃

3.The K-Value(heat transfer coefficient)
water and water:2000-7000w/m
water and oil:150-900w/m
Steam and water:1000-2000w/m
water and milk:1000-4000w/m

4.Heat transfer area A        Q=AK Tm         A=Q/ Tm.K=3329250W/17.38.4100=46.72

5.Confirm the model and the gasket

Following the flow rate ,we check it require the DN100 connection, Then our model is BR10MBL, The heat transfer area is the model is :  TL10M-10-157-E, with 157 pcs plate
The gasket is according to the temperature and the fluid
NBR  design temperature 110 ℃
EPDM design temperature 150 ℃

6.Check  the velocity in the connection and the two plate
Connection velocity W1 ≤ 3.5-4.5m/s
 Velocity between two plate=Flow rate/Pass x(corrugation depth-plate thickness)x plate width=0.1-0.4m/s
Then for this application W1=4q/3600. π D
2=4x65/(3600x3.14x0.12)=2.26m/s , it ok for this connection
Velocity between two plate=(65÷3600)/(39x0.0034x0.369)=0.37m/s, this is good.
So confirm the model is: TL10M-10-157-E
Pass: 2x39/2x39

Plate heat exchanger pressure drop

About the pressure, General, the customer  advice less than 150Kpa. The pressure according the  Velocity between two plate, if the velocity is quickly , the heat transfer coefficient is high, the pressure will so big. The designer will following the pressure drop requirement to adjust the heat transfer area.