Is it feasible to use 0.35 MPa saturated steam instead of 0.45 MPa saturated steam in the same heat exchanger?
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Is it feasible to use 0.35 MPa saturated steam instead of 0.45 MPa saturated steam in the same heat exchanger?
Changes in pressure and temperature, as well as variations in the stresses on the tube sheet, shell, and heat exchange tubes, will lead to changes in the stress distribution; it is recommended to perform recalculation.
Depends on the heat exchange temperature; design margin of the equipment
Changing this parameter is equivalent to redesigning the heat calculation; if the margin is small, it is likely to not work
It can be used within the specified pressure range without any problems! Efficiency needs to be taken into account!
This mainly depends on whether the temperature of the medium to be heated still meets the required standards. The temperature of saturated steam at 0.35 MPa is 139°C, while it is 148°C at 0.45 MPa – a difference of 9°C. If the temperature difference at the hot end of the heat exchanger remains unchanged, it means that the outlet temperature of the medium to be heated also has to decrease by 9°C. Will this still meet the process requirements? If the conditions are met, it can be used, but the quantity of material needs to be reduced, as the pressure is reduced and there is no issue with strength ； If the temperature is not met, it cannot be used.
It will certainly have an impact on the heat transfer efficiency, and it is necessary to conduct calculations to determine whether it can meet the requirements of the heat transfer process.
From the perspective of design pressure, there’s no problem. From the perspective of heat transfer efficiency, it is necessary to conduct calculations; as the temperature difference decreases, a larger surface area becomes required! The original design parameters are incomplete, so it’s not possible to make a simple judgment! Each specific issue must be analyzed on its own. Is it mainly about whether it can meet the process requirements? There should be no issues with security.
From the perspective of equipment safety, there is no issue; from a process perspective, it may not meet the requirements, and it is necessary to consider the design margin under the original process conditions. The poster needs to specify the process requirements for the other side as well in order to calculate and provide an answer
From a safety perspective, reducing the temperature is certainly no problem; the key is whether it can meet the process requirements. A decrease in steam pressure leads to a drop in the maximum heat exchange temperature, and process calculations are necessary. In fact, the difference in heat transfer capacity isn’t very large. Such changes require change management within chemical companies, with various functional departments simultaneously assessing any other associated risks