Calculation of safety valve discharge capacity under heat exchanger tube rupture conditions
Thread Content
I found several calculations in the literature regarding the discharge volume of safety valves under conditions of heat exchanger failure. The formula that is used most frequently is shown below; this formula is applicable when the high-pressure side is in gaseous state. However, at what pressure does the density of the gas in this formula refer to – high pressure, low pressure, or an average of both? This formula is derived from the following literature:
In the scenario of a cracked heat exchanger tube, when the formula is applicable to the high-pressure side where it is in a gaseous state, the gas density referred to is usually calculated under the conditions of the high-pressure side. This is because the design of the safety valve is primarily based on protecting the system from exceeding the maximum allowable operating pressure on this side, that is, the pressure on the high-pressure side. The calculation of gas phase density is usually based on the temperature and pressure on the high-pressure side, as this is the side that is directly driven by pressure when the gas is released. In practical applications, it may also be necessary to consider the effect of temperature on density, as well as the adjustment of density when operating conditions change. If specific operating conditions and material properties are available, the density can be calculated more accurately. .
https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1867133 TP410
I thought there was only an English version, which seemed too difficult to understand. Thank you for the Chinese version; now I can read it carefully.
I have read this literature; the author cites a problem with Condition 1, where ammonia is in liquid state under the operating conditions, which is an inappropriate example. Regarding the value of density, I believe it is appropriate to use the constant-pressure or critical pressure value.