How to control the liquid level of the ammonia cooler
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How should the liquid level of the ammonia cooler be controlled when the system is not operating at full capacity? Is it lower or higher than the normal liquid level, or is it kept at the normal liquid level? As a beginner, I’m not familiar with this, so I hope all fellow sailors can offer me some guidance. Thank you!
The low liquid level should be controlled, and the gas temperature at the ammonia outlet can also be regulated using ammonia pressure.
It is adjusted based on the ammonia cooling temperature at all times, and not according to the level of the liquid. As for the normal liquid level you mentioned, which is essentially the company’s target, in that case, it would be possible to discuss with the company and set another target when the load is not at full capacity
The ammonia cooling temperature (i.e., the temperature of the fluid cooled by ammonia) should be controlled, while there is no need to control the liquid level.
It should be lower than the normal liquid level, provided that the process cooling temperature requirements are met. A high liquid level will carry the liquid to the chiller section.
Generally, it is necessary to control the low liquid level to ensure that the ammonia cooler has sufficient space for phase change. Furthermore, if the liquid level is high and liquid ammonia boils, the gas phase is likely to carry liquid with it, which can result in high pressure at the compressor inlet and an increased load, leading to unnecessary energy consumption.
I think there is a misunderstanding upstairs. In fact, both the Casale and Topsoe processes use liquid level control, rather than controlling the pressure of ammonia or the temperature of the process gas. The reason for this is that ammonia coolers rely on the latent heat of vaporization of ammonia; by controlling the amount of vaporization, one can control the temperature. This has an advantage: when operating under varying conditions, it is sufficient to adjust the liquid level slightly based on the temperature of the process gas side to ensure normal operation. Personal opinion; hope experts will discuss it
The purpose of controlling the liquid level is still to maintain the temperature of the process gas after ammonia cooling.
The last edit to this post was made by ZZJJAA70 on 2009-10-12 at 15:34. There are two control methods for ammonia coolers. One type uses a accumulator; such coolers are filled with liquid ammonia, and control is primarily exercised over the pressure at the outlet of the accumulator, as different pressures result in different temperatures of the liquid ammonia. This method does not focus on controlling the level of liquid ammonia. The other type of cooler does not have an accumulator, and liquid ammonia enters the cooler directly; in this case, it is necessary to control the level of liquid ammonia.
The liquid level can be maintained at a normal level, while the temperature is primarily regulated by the pressure of gaseous ammonia and has little to do with the liquid level; the normal liquid level should already take into account the presence of liquid
8# Wang Jingliang: Right, ours is from Topso. That’s exactly what I want to ask – could you elaborate on your views regarding my question?