What is the function of the E7 shell-side inlet and outlet connection pipes in the low-temperature methanol washing process at Dalian University of Technology?
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The low-temperature methanol washing process at Dalian University of Technology uses a six-tower configuration. The fluid comes out of pump P2 (the feed pump for the carbon dioxide separation tower) and enters the shell side of E7 (the methanol heat exchanger). There are connection pipes (also known as bypasses, equipped with stop valves) on both the inlet and outlet pipelines of the shell side. What is the function of these pipes?
Is it to prevent the methanol temperature in the washing tower from becoming too high, by introducing cold methanol that does not undergo heat exchange, so that both the cold methanol and the methanol that has undergone heat exchange can be cooled? It’s just my personal opinion, about that place of yours, friend. :handshake
What is the relationship between the temperature of the E7 heat exchanger and that of the inlet to the washing tower?
Does the heat-exchanged methanol return to the desorption tower? How many heat exchangers does this stream of methanol pass through?
The cooling capacity of E3 and E4 is adjusted by changing the amount of cold methanol fed into E7, thereby regulating the load on the refrigeration system
The colder the methanol in the shell side, the more cooling capacity it provides for the methanol in the tube side. As a result, less cooling medium is required for E3 and E4, and the load on the refrigeration plant is reduced accordingly, which helps save energy! Is this bypass provided in the shell side to reduce the cooling capacity supplied to the tube side?
How can methanol flow through both the shell side and the tube side? I am working on my graduation project on the heater for a distillation tower (a shell-and-tube heat exchanger has been chosen). Let the pipeline carry steam! ! !
I am also working on a heat exchanger as part of my graduation project. The information I found seems to meet the requirements: adding bypasses at the cold or hot end of the heat exchanger increases the degree of control available, which helps to ensure smoother operation. When a bypass is added to the heat exchanger, the degree of design margin of the heat exchanger is crucial for the effectiveness of bypass control. Currently, when performing process design, the amount of design margin is usually determined based on design experience, which results in either an excessive area margin for the heat exchanger or an insufficient design margin, making it difficult to meet the control requirements. Sun Lin and others proposed a method for quantitatively determining the design margin of heat exchangers, and conducted a comparative analysis of the operating margin, fouling margin, and control margin in bypass design, thereby laying the foundation for the optimized control of bypass systems. Examples have shown that it is essential to quantitatively determine the design margin, and the use of bypasses enables the heat exchanger to meet all control requirements while ensuring stable operation. By analyzing the design margins of the heat exchangers and the bypass design, the control efficiency of the heat exchange network was improved, laying a foundation for energy savings and reduced consumption
I think the CO2 purity of this bypass T102 product is related to this; the process designed in Dalian increases the production of CO2, causing the methanol-rich stream after heat exchange to enter the lower part of T102 where it flashes again. Such high temperatures result in a larger amount of H2S flashing, which affects the purity of CO2! It is also possible to increase the recovery rate of effective gases such as CO and H2!
The main thing is to understand this sentence (the rest can be ignored): \"Adding bypasses at the cold or hot end of the heat exchanger increases the degree of control flexibility, which helps to ensure stable operation.\" I’m not sure if the original poster is familiar with the control theory in process equipment – there are concepts such as single-loop control systems and complex control systems. Increasing the number of control degrees of freedom is equivalent to using a complex (cascade) control system. Simply put, when one control system is not able to meet the requirements of production, another control mechanism is installed to provide compensatory control, thereby ensuring accuracy and timeliness in control
Used to adjust the cooling capacity. . The methanol from this section bypasses the heat exchanger and goes directly to the outlet. . To meet the rich methanol temperature required for outlet E7, or to control the temperature going directly to tower C2, either approach is possible. . It depends on the relevant process parameters of yours