Plate heat exchanger: seeking help from friends in Sichuan, and also looking for manufacturers.
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Here’s the situation: I’m investing in a hot water project with a friend, and plate heat exchangers are needed for it. I’ll share the parameters with you first. Water/water heat exchange – Heat source: 140°C steam condensate (liquid), 0.35 Mpa. Output: 0.28 Mpa. Cold water: 5°C, 0.4 Mpa, 40 t/h, at atmospheric pressure at the plate heat exchanger outlet. Requirements: 1. Hot water: 85°C, flow rate of 40 t/h ； 2. Calculate the steam condensate demand, with the condensate outlet temperature < 60°C. 3. Pipe diameter requirements for water and condensate. This is a parameter. Then I searched online for heat exchanger manufacturers, and the heat exchangers they offered came in different sizes, although they were made from the same material. The first one offered 38.4 square meters, made of 304 stainless steel. The second one is 20 square meters, made of 316 stainless steel. The third one is 120 square meters, made of 304 stainless steel. The deviation is way too large. I’m at my wits’ end. So I can only turn to my friends from Sichuan. Also, please help introduce reliable heat exchanger manufacturers. It’s better to be near Henan.
Friend, I wonder if you’ve managed to get information on this heat exchanger?
For your operating conditions, does the outlet pressure need to reach the value you specified, or is it acceptable if it’s lower than that? A pressure drop of 70 kPa on the hot side is considered normal; however, the pressure drop on the cold side is too high. Assume for now that 0.4 MPa represents the absolute pressure, resulting in a pressure drop of nearly 300 kPa. Typically, heat exchanger manufacturers assume a pressure drop of 50 kPa. If such a high pressure drop is indeed required, the four ports will not likely be on the same side, which means multiple flow paths – and this makes cleaning and disassembly more complicated. Therefore, you need to make it clear to the manufacturer you’re choosing: among the three area values you provided, the third one seems too large. I’ll do some calculations using Alfa Laval’s model M10M; the area in that case would be around 25 square meters, with 4 flow paths on the hot side and 7 flow paths on the cold side. If the pressure drop of the heat exchanger is lower than what you require, that’s also fine. For example, if you require a pressure drop of 300 kPa, the heat exchanger I calculate would have only a pressure drop of 50 kPa, in which case the area would be around 20 square meters, with single flow paths, making cleaning and maintenance easier. As for the 20 square meter and 38 square meter options provided by the manufacturer, either one is acceptable; the designs are different, and different designers are involved, which results in varying dirt coefficient values and thus different areas. The difference isn’t very large, so there’s generally no problem – both options can function properly. The important thing is that the parameters and conditions you provide must be accurate and free of any ambiguity.
You can estimate the pipe diameter yourself; a flow rate of 1–1.5 is sufficient. If the connectors provided by the manufacturer don’t fit, you can use an adapter, or you can simply request from the manufacturer that flanges of DN100 be used so that they fit your pipelines perfectly.
Have you gotten a quote for your plan? My estimate is around 20 as well; it’s not a large heat exchange area.
My cold water test showed that the water was going into the hot water tank. So it is written as normal pressure.
Using a plate exchanger with 20 is sufficient; the price is less than 10,000 yuan
If it’s convenient, add me on WeChat: A949984070
This post was last edited by Heat exchanger or Plate heat exchanger on 2020-9-1 16:40. I just saw your post and wonder if you’ve found what you were looking for. I am a manufacturer of plate heat exchangers. My QQ number is 1035366037; my factory is located in Zhuzhou, Hunan. I will answer your questions one by one: 1. To heat 40 t/h of water from 5°C to 85°C, the heat transfer capacity required is 3756 KW. 2. Steam condensate at 140°C is used as the heat source, with the exit temperature of the condensate being less than 60°C. The demand for steam condensate is also 40 t/h (with the specific heat densities taken as 1000 and 4.226 respectively; any discrepancies are ignored). ) 3. Diameter of pipes for water and condensate: DN80. 4. Heat exchanger area: This is a scenario with a large temperature difference; while it is necessary to heat one side, the condensate also needs to be cooled below 60°C. Therefore, a 3/3 configuration is required, and the heat exchange area needed is 93 square meters (BR06K model). It should be noted that the selection and calculation of heat exchangers require expertise; it is not sufficient to consider only the area involved. A comprehensive evaluation is needed based on different operating conditions, taking into account the manufacturer’s plate heat exchanger models and process design. 5. Regarding the material of the plates: it needs to be selected based on the chloride ion content in your medium. 304 is generally used; if the chloride ion concentration exceeds 50 mg/L, 316L should be used. 6. As for the material selection for the first and second units, it’s not clear what type of plate is being used, but there is a high likelihood of errors, as this is a scenario where the temperature difference between the hot and cold sides is 80°C. It will be difficult to achieve satisfactory results with a small area, and a multi-stage design is necessary.