1) insufficient cooling water. The heat of the air is not enough to be taken away by the cooling water, resulting in the increase of the next level of suction temperature, the decrease of gas density, and finally the reduction of exhaust volume. Therefore, the water supply pressure of cooling water should be closely monitored during operation to control the water supply. The process generally requires that the cooling water pressure should be greater than 0.15MPa (surface pressure );
2) cooling water temperature is too high. High water temperature reduces the temperature difference between water and gas, and reduces the effect of heat and cooling. Even if the amount of cooling water is not reduced, the temperature will still be very high after gas cooling;
3) There are too much scale in the cooling water pipe or it is blocked by sediment and organic matter, as well as moisture precipitation after cooling on the air side of the cooler, which can not be discharged timely, all of which will affect the heat transfer area or the heat transfer working condition, and affect the cooling effect. The cooling effect is not good, which makes the temperature of the next level rise, affects the performance curve of the next level, and reduces the outlet pressure and flow. Figure 98 shows the change of the performance curve of a compressor obtained from the experiment when the temperature of cooling water rises from 10℃ to 30℃. In addition, when the suction volume of the lower level is reduced, it will cause that the air produced by the former level can not be "eaten in" completely, and it is easy to make the work of the former level enter into the surge area, and surge occurs at this level. Treatment methods include: check the temperature and pressure of the upper water and make adjustments; if the temperature and pressure of the upper water are normal, stop and disassemble to check, use physical and chemical methods to clean or replace the cooler; if the cooler leaks, replace the cooler.
