Who figured it out? Please explain
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Today I saw a post that explained the principle of temperature-reducing pressure regulators. At the end, it said, “Regardless of the type, temperature-reducing pressure regulators first reduce the pressure and then reduce the temperature. Can you figure out why?” “ I haven’t figured it out yet. Has anyone figured it out? Please share
Temperature and pressure reducers – I only know that they are used for water and steam; those I’ve seen reduce pressure first and then temperature. There are also those that reduce temperature without lowering pressure (the steam remains superheated after the temperature is reduced).
If the temperature is reduced first, the steam will enter the saturated zone first; when the pressure is then reduced, condensate water is generated, which hinders the control of the cooling water thereafter.
According to the ideal gas law, when the volume remains constant, temperature is directly proportional to pressure; therefore, as pressure decreases, temperature also decreases.
Without pressure reduction, the steam remains superheated; if the temperature is lowered first, condensate will form
There are temperature changes during the pressure reduction process, while during the temperature reduction process essentially only cooling can be achieved. Therefore, it is necessary to first carry out the process with more changes, and then one with fewer changes, so as to facilitate simultaneous control of both the outlet temperature and pressure
What the title says is correct. The explanation upstairs is very clear
At saturated steam, temperature and pressure are in a one-to-one correspondence. If the temperature is reduced first while the pressure remains constant, condensate will form, causing water hammer in the pipes. If pressure is reduced first, the water vapor will be in a superheated state; at this point, adding an appropriate amount of water to lower the temperature will achieve the desired result.
Both temperature and pressure reducers first reduce the pressure before reducing the temperature; if water is added first to lower the temperature, water hammer will occur.