What are the reasons for the excessively high inlet temperature of ammonia compressors (chillers) (double-screw compressors)?
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Let’s start by discussing our manufacturing process. The reactions that take place in the polymerization reactors in our factory generate a large amount of heat, which is cooled using liquid ammonia. The ammonia gas produced is sent to a gas-liquid separator, where it is then compressed by an ice machine. After that, it is condensed into liquid ammonia through a heat exchanger, before being sent back to the polymerization unit. The entire ammonia system operates on a closed-loop basis. In recent days, the inlet temperature of the chillers has been very high, exceeding 20 degrees, with the highest values reaching over 60 degrees. I’ve worked at Shandong Qilu Petrochemical, and I’ve never seen temperatures this high there; I’ve never witnessed the temperature at the inlet of the chiller exceeding 15 degrees. I hope the experts here can help me analyze the reason
I basically agree with the view expressed on the second floor; the main reason for the high inlet temperature of the chiller is a short circuit in the flow of the compressed gas. The evaporation temperature of ammonia cannot exceed 50°C, and it is only when the temperature of the compressed gas returns that the inlet temperature of the chiller rises.
Reply to 2# yg20080707: I checked the chiller; there are no return pipes
There could be the following reasons: First, the system load increases, and the cooling capacity isn’t adjusted properly, resulting in an excessive cooling load. Second, the capacity of the chiller is insufficient, and the inlet temperature rises as the inlet pressure increases. Third, there may be issues with the instruments. Fourth, there are faults in the chiller circuit. Fifth, if the temperature is in the high 20s, it might mean that the insulation effect isn’t good enough; however, a temperature of over 60 degrees is abnormal
Reasons for high inlet temperature of the chiller: 1. The temperature of the gaseous ammonia coming from the ammonia evaporator is high, and the evaporator is not functioning properly; 2. The insulation around the gaseous ammonia pipeline is inadequate, resulting in a high superheat level; 3. If the inlet temperature reaches 60 degrees, it is necessary to check whether there is a pipeline leading from the chiller’s outlet to its inlet, and whether the valve on that pipeline (the bypass valve) is open.
1. The inlet temperature of the ice machine is high; as a result, the load on the ammonia cooler is low, the amount of liquid ammonia that evaporates is small, and the temperature of the ammonia entering the ice machine is high (i.e., it is equivalent to the temperature of the liquid ammonia coming out of the ammonia receiver tank). 2. The circulating water in the oil cooler of the screw compressor is not flowing properly, resulting in a high oil temperature that in turn causes high temperatures at the inlet and outlet of the ice machine
1. The liquid level in the ammonia cooler is too low, resulting in insufficient liquid supply to meet the evaporation requirements. 2. There is not enough ammonia in the system. 3. The insulation layer of the gaseous ammonia pipeline is of poor quality, causing overheating
Could you tell us the model and manufacturer of your ice machine? We are interested in purchasing one
Check how high the temperature of the liquid ammonia you are condensing is; the temperature at which the liquid ammonia is added also affects the temperature of the gaseous ammonia after evaporation.
What the people upstairs said makes sense: First, the system load increases, and the amount of refrigeration provided isn’t adjusted properly, resulting in an excessive refrigeration load； II. The capacity of the chiller is insufficient; the pressure of gaseous ammonia is too high, and the inlet temperature increases as the inlet pressure rises ； III. Excessively high or low liquid level in the ammonia evaporator ； IV. The purity of liquid ammonia is insufficient, and there is too much oil and water in the ammonia evaporator ； V. The insulation effect of the pipes may be poor; since the pipes are long, there is significant heat loss.