Industrial chillers four common causes of failure analysis
AMC AMC 2016-05-25 17:31:17
Industrial chillers range more widely, in the course of more or less will encounter problems, analyze today on the more common causes of four faults. First, the intake air temperature is too high need to distinguish between the suction temperature does not mean that high suction pressure is high, because the suction superheated steam is absorbed, causing the intake air temperature is too high mainly due to the suction superheat increases caused by industrial chiller compressor cylinder head under normal circumstances should is half cold, half of the heat if the temperature is too high suction head all the heat if the temperature is higher than normal intake, exhaust temperature will be a corresponding increase in the intake air temperature is too high main reasons are: 1, cold water machine system refrigerant charge insufficient fluence, even at maximum expansion valve, the liquid volume will not have any change, so the refrigerant vapor in the evaporator superheat the suction temperature. 2, through the expansion valve opening small, resulting in insufficient circulation amount of refrigerant in the system, the less the amount of refrigerant into the evaporator superheat large, so that a high intake temperature .3 expansion valve port filter clogging, inadequate for the amount of fluid within the evaporator, the refrigerant reduce the amount of liquid inside the evaporator part is occupied by superheated steam, so the intake air temperature rise. 4, other causes of the intake air temperature is too high, such as the return air duct or pipe insulation is not good for too long, can cause aspiration temperature is too high. Second, the intake air temperature is too low for the amount of liquid chiller evaporator partial Assembly resulting in low suction superheat. 1, charge excessive fluence chiller refrigerant in the condenser portion of the volume occupied leaving condensing pressure increased, the liquid entering the evaporator will be increased. evaporator liquid can not be completely vaporized, the compressor inhalation gas with droplets of liquid, so that the temperature drop of the gas pipeline, but the pressure is not due to the evaporation temperature decline without change, superheat decreases, even off a small expansion valve .2 no significant improvement, expansion valve through the large, due to the temperature sensing element binding too loose, a small area in contact with the back to the trachea, or the temperature sensing element is not used insulation wrap and wrap position errors, causing the measured temperature sensing element is not accurate, close to ambient temperature, the degree of opening of the expansion valve operation increases, resulting in excessive liquid supply. 3, the exhaust gas temperature affect chiller Causes include adiabatic index, compression ratio, intake air temperature compressor discharge temperature can be read out from the exhaust pipe on the road thermometer. it adiabatic index refrigerant compression ratio (condensation pressure / the evaporation pressure) and the suction temperature related The suction temperature, the higher the compression ratio, the exhaust gas temperature is higher, and vice versa constant suction pressure, discharge pressure rises when the exhaust gas temperature rises; if the constant discharge pressure, suction when the pressure drops, the exhaust temperature also rises. both cases are caused because the compression ratio increases. condensing temperature and the exhaust temperature is too high is detrimental to the operation of the compressor and should be prevented. exhaust temperature lubricating oil is too high thinning even carbonization coke, so that the compressor lubrication conditions deteriorate exhaust temperature and the level of compression ratio (the condensing pressure / evaporation pressure) and the temperature is proportional to the suction, the suction superheat temperature is high, the compression ratio, the temperature is also high, if the inspiratory pressure and temperature constant, when the exhaust pressure rises, the exhaust gas temperature rise caused by industrial chillers exhaust temperature of the exhaust main reasons are: 1, the intake air temperature is higher, the refrigerant vapor is compressed exhaust gas temperature will be higher. 2, the condensing temperature, the condensing pressure is also high, resulting in exhaust temperature. 3, exhaust valve film was shot broken, repeated high-pressure steam is compressed and the temperature rises, the hot cylinder and the cylinder head, the exhaust pipe thermometer indication value also rises actual exhaust temperature factors are: low-intermediate cooling efficiency or cooler inside scale impact of excessive heat, the subsequent stage of the inevitable high intake temperature, exhaust gas temperature will rise. valve leakage, piston ring leak, not only affects the exhaust temperature, but also make the grade Room pressure changes, as long as the compression ratio will be higher than normal temperature of the exhaust gas. in addition, water-cooled chiller in the water or not enough water causes all the exhaust temperature, the condensing pressure is not normal and reduced exhaust pressure Third, the higher the exhaust pressure caused by exhaust pressure industrial chillers and the main reason is the high condensing pressure, rather than press for their own reasons. exhaust pressure is generally the condensation temperature corresponding to the level of under normal circumstances, compressor discharge pressure and condensing pressure is very close. when the chiller condensing pressure rises, the compressor discharge temperature also increased compression ratio of the compressor increases, the gas transmission coefficient decreases, so that the cooling capacity of the compressor reduce power consumption increases if the exhaust temperature is too high, and an increase of the compressor oil consumption, thinning the oil, affecting lubrication; when the exhaust temperature and compressor oil flash point close, but also so that part of the lubrication carbonized and accumulate in the oil suction exhaust port, the impact of the valve seal. the temperature can be reduced so that the cooling medium condensation temperature drops, the condensing pressure will drop, but is limited by environmental conditions, difficult to artificial selection increase coolant flow can be a little lower condensing temperature (more than using this method), but can not unilaterally increase the flow of cooling water or air, as this will increase the cooling water pump or fan and motor power should be fully considered. exhaust pressure high compression work will increase gas transmission coefficient decreases, so that the cooling efficiency decreased mainly due to industrial chillers produce this failure: 1, the cooling water (or air) low flow, high temperature; 2, within the system. air, the condensation pressure increases; 3, charging excessive fluence refrigerant liquid occupied the effective condensation area; 4, a condenser disrepair, heat transfer surface dirt serious, can also lead to increase in the presence of condensing pressure scale. Effect of condensing pressure as well. Fourth, the exhaust gas pressure is too low exhaust pressure is mainly low industrial chillers pipe cooling system refrigerant flow is too small or even stop causing exhaust pressure is too low, although the phenomenon is manifested in high-pressure side, but the reason to produce more low-voltage side of the reasons: the expansion valve ice blocking or fouling and clogging of the filter, etc., is bound to suction and discharge pressure has fallen industrial chillers in different environments and conditions. The system should be different.
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