Help me take a look at this heat exchanger design problem
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I’m currently working on my graduation project, and its title is “Design of a Heat Exchanger with a Heat Exchange Area of 579 Square Meters.” Just looking at this title already gives me a headache. I think everyone can see the problem as well. It was only later that I found out this topic was taken from a completed design drawing; all the drawings were given to me and they were design drawings for xx Chemical Plant. After noticing the problem, I went to see the teacher; we talked for a long time but it didn’t help – he was even more confused than I was. Well, in the end I said I’d go back and change the conditions, but the main topics couldn’t be changed. How to design a heat exchanger with a limited heat exchange area? ? Are there such questions in reality? The key thing is that there’s no specified workload!!!! The teacher told me to estimate the data usage myself, but I don’t know where to start. How to choose a data volume to meet 579. It feels like I’m creating the questions myself and then answering them. Conditions: Shell side, tube side, cooling water, oxidized exhaust gases. Operating temperature: 33/43 °C; 125.5/36.5 °C. Operating pressure: 0.4/1.1185 bar. Design temperature: 110/228 °C. Design pressure: 0.75 Mpa/1.86 Mpa. Corrosion allowance: 0/1.5. Weld joint factor: 1.0/0.85. Number of passes: 1/1. Heat treatment: No/No. Hydrostatic test pressure: 0.94/2.65 bar. Heat exchange area: 579. I calculated the heat exchange area based on a certain flow rate; there is a margin of 18.4% – I’m not sure if this is acceptable ?
This already provides you with ample room to design; you can decide on the diameter of the heat exchanger, the number of tubes, and the length of the heat exchange tubes yourself. As for things like converting flow rate to heat exchange area or pressure drop, as well as the size of the pipe openings, these are considerations from the process side. If you need to design and calculate both the process and the equipment, then that’s another matter. This post was last edited by Wen Bing on 2008-5-24 07:51]
It seems the questions given don’t have much practical relevance! ~~
The data is provided, but it has no physical properties; it cannot be simulated. It needs to be calculated manually, which is quite troublesome
First, without material data, the calculation is meaningless； Second, there is no flow of materials that require cooling, as such situations do not occur in reality ； The temperature of the third cooling water supply is 33°C; after cooling, the material’s temperature is required to reach 36.5°C, and a larger area is indeed necessary for this purpose
These types of questions are of little value in terms of design. To specifically design a project, it is necessary to provide the flow rate or heat exchange amount in order to calculate the size of the equipment interfaces. Determine the flow velocity in the tube and shell sides, decide on the number of tube and shell sides in the heat exchanger, determine the structural design of the equipment, and select materials appropriately based on the medium and temperature.
What is the real value of the practice exercises at school? Just design something that can “hold up on its own” and be consistent.
I wonder whether it’s because there are too many students in schools these days or teachers are too busy, that the topics for graduation projects are such shoddy.
“This already provides you with ample room to design; you can decide on the diameter of the heat exchanger, the number of tubes, and the length of the heat exchange tubes yourself. As for things like converting flow rate to heat exchange area or pressure drop, as well as the size of the pipe openings, these are considerations from the process side. If you need to design and calculate both the process and the equipment, then that’s another matter. ” Agreed. In fact, the graduation project is mainly aimed at familiarizing oneself with the entire design process of equipment, serving as a preparation for entering the workplace; there is no need to place too much emphasis on its practical significance.