Calculate the heat exchange area
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I would like to ask fellow sea users: the inlet on the hot side is saturated steam at 0.4 MPa； The cold-side inlet is a 40% ethylene glycol solution, which is pumped to the cold side; the flow rate is Q=35 m3/h and the head loss is H=30 m. Heat is circulated for heating, with a total heat exchange requirement of 200,000 Kcal/h. What area is required for the plate heat exchanger?
To calculate the required area of a plate heat exchanger, it is first necessary to know data such as the specific heat of the ethylene glycol solution and the inlet and outlet temperatures in order to determine the total heat capacity. In addition, it is also necessary to understand parameters such as the heat transfer coefficient on the hot side and the possible heat transfer efficiency. Assuming these parameters are known, the formula is: \ Where: – \( Q \) is the total heat transfer rate (200,000 Kcal/h) – \( U \) is the overall heat transfer coefficient (which needs to be determined by consulting relevant sources) – \( A \) is the heat transfer area (which we need to find) – \( \Delta T_{lm} \) is the logarithmic mean temperature difference. For example, if \( U \) is assumed to be around 1000 W/m·K and calories are converted to joules (1 Kcal = 4184 J), the average temperature difference can be calculated after adjusting the units, and thereby the corresponding value of \( A \) can be obtained. (The logarithmic mean temperature difference generally requires knowledge of the specific inlet and outlet temperatures on the hot side and the cold side.) Due to the lack of detailed parameters such as specific heat and temperature differences, an exact calculation result cannot be provided here; you need to supply these key data before using the aforementioned formula for calculation. .
I just don’t know the process conditions after the steam at 0.4 MPa on the hot side passes through the plate exchanger; the initial temperature on the cold side is 25 degrees, and the total heat exchange capacity required is 200,000 kcal
When stainless steel heat exchangers are used for steam heating, the heat transfer coefficient should be more than 1000
20W kcal = 830,000 kJ = 232.5 kW; Q = 35 m³/h. The temperature rise is around 10°C. Using the conventional value of K = 3000–4000 for stainless steel plates, the heat exchange area comes out to be practically non-existent after performing the calculations. . . About 1 ping, I guess. . . I’m not sure either what the difference is in my calculations compared to those of the experts here
Provide the temperature on the cold side as well as the allowable diameter. If neither of these is available, an approximate area of 3-4 square meters can be estimated; the diameter should be DN65 (depending on the flow rate on the cold side). We are a professional manufacturer of plate heat exchangers – feel free to contact us for free consultation