Ice machine evaporation and refrigeration
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This post was last edited by 654262293 on 2010-8-17 14:19 The synthetic ammonia system operates two 31.5 screw ice machines and one ice machine with a cooling capacity of 440,000Kcal, five evaporative cooling machines with a capacity of 2150KW, and four plate cooling machines. The ammonia pressure at the outlet of the ice machine is 1.45MPa. Is it too high? We have used evaporative coolers from three manufacturers in parallel, but the discharge temperatures are very different. One unit is at 40°C, two are at 37°C, and two are at 31°C. Which one do you think does the most work? Is it related to the position of the liquid outlet of the ice machine? Is it related to the position of the non-condensable gas emission at the ice machine inlet? The drain pipe is not equipped with a liquid trap and the ammonia discharge valve is basically opened. Will gas ammonia return to the liquid storage tank? Each cooler and liquid storage tank are equipped with balance pipes. Please express your opinions and share with us the problems and solutions that have occurred in the past. Thank you!
Reply 1# Courtyard Shen I think the condenser with a higher discharge temperature has a heavier load. I wonder whether the balance pipe is connected to the condenser discharge port or the condenser inlet? There are installation requirements for the vertical height of the evaporative ammonia condenser drain port. The manufacturer recommends that it be no less than 2M. In addition, are the plate cooler and evaporative ammonia condenser connected in parallel or in series? Have the inlet valves of each evaporative ammonia condenser been opened? From what you said, the outlet pressure of the ice machine is not high. The heat discharged by the condenser is still sufficient, but the condenser inlet valve with low discharge liquid temperature is fully opened? The low discharge temperature after the valve is turned on may be due to the lack of a drain trap.
Different evaporative cooling manufacturers have different models and related sizes, and there will definitely be differences in evaporation volume. However, I feel that the impact should not be too great. However, as the original poster said, the difference is so large. It is recommended to consider whether it is caused by the large difference in the amount of ammonia distributed by each evaporative cooling system.
The outlet pressure of the ice machine is determined by the local circulating water temperature. If the circulating water temperature is low, the ice machine outlet pressure can be lower. If the circulating water temperature is high, the ice machine outlet pressure will increase.
The outlet pressure of the ice machine is not only related to the temperature of the circulating water but also to the heat exchange effect of the heat exchanger.
The outlet pressure is high. Our factory has two 25-screw ice machines and one 31.5-screw ice machine. The maximum outlet pressure is around 1.2MPa. It may be because the large evaporative condenser of your ice machine is not enough. We have four evaporative cooling machines. The temperature is different, which is related to the parallel connection. The air intake volume is uneven. Adjusting the inlet valve can have an effect.
The evaporative coolers used by the poster are from three manufacturers. Do they have the same internal structure? Is the cooling water volume the same? Are the nozzles the same form? Are the air volumes of the fans the same? If different, the effect is different ； Evaporative coolers are installed in parallel. If there is no valve to control the air volume, the air intake volume of each evaporative cooler is different. ； The vertical installation height of the evaporative cooling liquid drain pipe is required to be >2m, otherwise it is easy to cause air leakage.