2013 Professional Knowledge Morning, Question 35
Thread Content
What will be the effect of increasing the vacuum level of the evaporator on the evaporation system? A increases the heat transfer temperature difference of the heater; B increases the heat transfer temperature difference of the condenser; C improves the overall heat transfer coefficient of the heater; D reduces the pressure drop in the secondary steam system. My guess is D. Please have an expert explain it.
An increase in vacuum level indicates a decrease in absolute pressure; obviously, the boiling point of the solution will drop, and as a result, the heat transfer temperature difference T-t will increase.
Please refer to http://bbs.hcbbs.com/thread-464370-1-1.html; the answer regarding the sofa is correct, taking into account the analysis provided in the post above.
http://www.zbbz.com/images/dxns.jpg As the vacuum level increases, if the dynamic pressure drop of the secondary steam is understood as the pressure difference between the steam and the outside environment, then this pressure drop should increase.