Treatment of high pressure fault and oil leakage of water chiller

There are two types of cooling units and water-cooling units Fan refers to the direct exchange of fresh air for refrigeration or heating Water machine refers to the first cooling or heating of hot medium water to be sent to the fan coil air conditioning system, and the heat or cold energy will be sent to the designated area by fresh air or mixed air at the end Chillers are also called: chillers, chillers, chillers, cooling equipment, etc because of the wide use of all walks of life, the requirements for chillers are not the same The chiller consists of four main parts: compressor, evaporator, condenser, expansion valve, so as to achieve the cooling and heating effect of the chiller The high-pressure fault of chiller refers to the high discharge pressure of compressor, which results in the action of high-pressure protection relay The discharge pressure of the compressor reflects the condensation pressure, the normal value should be 1.4 ~ 1.8MPa, and the setting of the protection value should not exceed 2.0MPa Because the long-term pressure is too high, it will lead to the compressor running current is too large, easy to burn the motor, causing damage to the compressor I what are the main causes of high voltage fault? 1 Too much refrigerant is charged This kind of situation generally occurs after maintenance, which shows that the suction and discharge pressure, balance pressure are high, and the running current of compressor is also high Solution: the refrigerant shall be discharged according to the suction and exhaust pressure, balance pressure and operation current under the rated working condition until it is normal 2 The cooling water temperature is too high and the condensation effect is poor The rated working condition of cooling water required by chiller is 30 ~ 35 ℃, high water temperature and poor heat dissipation will inevitably lead to high condensation pressure, which often occurs in high temperature season Solution: the cause of high water temperature may be the failure of cooling tower For example, the fan is not opened or even reversed, and the water distributor does not turn, which shows that the temperature of cooling water is very high, and it rises rapidly; the external temperature is high, the water path is short, and the amount of circulating water is small In this case, the temperature of cooling water is generally maintained at a high level, which can be solved by increasing the storage tank 3 The cooling water flow is insufficient to reach the rated water flow The main performance is that the pressure difference between the inlet and outlet water of the unit becomes smaller (compared with the pressure difference at the beginning of system operation), and the temperature difference becomes larger Solution: if the pipeline filter is blocked or selected too fine, and the water permeability is limited, the appropriate filter shall be selected and the filter screen shall be cleaned regularly; or the water pump shall be selected smaller, which is not matched with the system 4 The condenser is scaling or blocked Generally, tap water is used for condensate water, which is easy to scale when the temperature is above 30 ℃ Moreover, because the cooling tower is open and directly exposed to the air, dust and foreign matters are easy to enter the cooling water system, resulting in dirty and blocked condenser, small heat exchange area, low efficiency, and also affecting water flow Its performance is that the pressure difference and temperature difference between the water in and out of the unit become large, the temperature of the condenser is very high when touching it by hand, and the liquid outlet copper tube of the condenser is hot Solution: the unit shall be backwashed regularly, and chemical cleaning and descaling shall be carried out if necessary 5 False alarm caused by electrical fault Due to the damp, poor contact or damage of the high-voltage protection relay, the unit electronic board is damp or damaged, and the communication fault causes false alarm Solution: for this kind of false fault, the fault indicator light on the electronic board is not on or slightly on, the manual reset of the high-voltage protection relay is invalid, the running current of the compressor is normal, and the suction and exhaust pressure are normal 6 The refrigerant is mixed with air, nitrogen and other non condensable gases There is air in the refrigeration system In many cases, the pointer of the high-pressure meter shakes severely when there is a lot of air Solution: this kind of situation usually occurs after maintenance, and the vacuumizing is not complete It can be emptied or re vacuumized at Zui high point of condenser after shutdown Oil leakage treatment of water chiller: A: the oil is in the evaporator At this time, pay close attention to the temperature of chilled water, which can first reduce its flow rate appropriately, reduce the temperature of the effluent water, and then rapidly increase the flow rate, so that the temperature of the evaporator outlet water rises rapidly At this time, the water temperature will exceed the saturation temperature of the refrigerant, so that the refrigerant will boil fiercely, and the frozen oil will be sucked like the compressor of the refrigerant foam, so the temperature should be reduced However, the separation temperature of the oil and the refrigerant should also be much higher, so as to bring the oil back to the oil separator and separate them Several times, the oil will be recovered to the oil separator Pay attention to the time interval of each adjustment of water volume Zui is good to make the exhaust temperature rise to Zui before adjustment after each adjustment B: the oil is in the condenser At this time, it is not necessary to pay much attention to the water temperature, as long as the unit can operate normally, there will be no big problem At this point, the expansion valve should be gradually opened to Zui large (the opening process is not too fast, to prevent excessive liquid supply damage to the copper tube in the evaporator), and wait for a few minutes until the balance of the unit is high and low pressure At this time, a large amount of white foam can be seen from the evaporator's liquid lens, which means that the oil has entered the evaporator from the condenser Just repeat step a and the oil will come back soon.