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Central air conditioning maintenance details and procedures

作者:xuemei 点击:181 发布时间:2020-09-16

 1、 Maintenance classification of central air conditioning


1. Inspection maintenance:


(1) Carry out all kinds of routine inspection in a planned way based on equipment operation and customer requirements;


(2) Guide the owner's operators on site and explain the practical technology related to unit operation and maintenance;



(3) Provide all kinds of necessary value-added services



(4) Provide professional advice and improvement plan for the problems existing in the operation of main engine and auxiliary equipment.


2. Preventive maintenance:


(1) Including the contents of inspection and maintenance;


(2) Carry out necessary preventive maintenance according to the manufacturer's recommendation;


(3) Preventive maintenance includes cleaning the copper tube of heat exchanger, analyzing and changing the refrigeration oil, oil filter element and drying filter.


3. Comprehensive maintenance:


(1) * comprehensive and thorough maintenance plan, including all routine inspection, value-added services and emergency troubleshooting services;


(2) In case of equipment failure, be responsible for all maintenance work and parts replacement.


4. Emergency maintenance:


According to the needs of customers, 24-hour emergency maintenance service is provided for customers. The developed service network and high-quality service personnel team ensure quick troubleshooting and short downtime.


5. Energy saving transformation:


Energy saving transformation means that the cooling water pump and cooling fan motor are driven by frequency conversion, and the frequency conversion speed regulation of water pump and fan is realized according to the temperature change of chilled water outlet, so as to realize energy saving and consumption reduction.


6. Analysis of refrigeration oil:


The quality of lubricating oil can fully reflect the internal mechanical operation status and operation trend of the compressor. The metal content, humidity and acidity of the lubricating oil are the key indicators that may lead to major equipment failure. The professional oil analysis provided by us can provide improvement suggestions to you at the critical moment, eliminate the major hidden trouble of the unit in advance, avoid accidental shutdown and high maintenance costs, and protect the equipment Your investment.


7. Maintenance and reconstruction of cooling tower, water pump, fan coil unit, fresh air unit, etc.


2、 Maintenance contents of central air conditioning system


1. Main unit of air conditioner:


(1) Check whether the high pressure and low pressure of the refrigerant in the refrigeration system of the air conditioner are normal;


(2) Check whether there is leakage of refrigerant in the refrigeration system of air conditioner host and whether it is necessary to supplement refrigerant;


(3) Check whether the running current of compressor is normal;



(4) Check whether the compressor operates normally;



(5) Check whether the working voltage of compressor is normal;



(6) Check the oil level and color of the compressor;



(7) Check whether the oil pressure and oil temperature of the compressor are normal;



(8) Check whether the phase sequence protector of the air conditioner is normal and whether there is phase loss;



(9) Check whether the wiring terminals of the air conditioner host are loose;



(10) Check whether the water flow protection switch works normally;



(11) Check whether the resistance of computer board and temperature probe is normal;



(12) Check whether the air switch of the air conditioner host is normal; whether the AC contactor and thermal protector are in good condition.



2. Air system inspection:



(1) Check whether the air volume of fan coil unit is normal;



(2) Check the return air filter screen of fan coil unit for dust accumulation;



(3) Check whether the outlet air temperature is normal.



3. Inspection of water system:



(1) Check the quality of cooling water and chilled water, and whether it is necessary to replace water;



(2) Check the impurities in the filter screen of cooling and chilled water system, and clean the filter screen;



(3) Check whether there is water in the exhaust system;



(4) Check whether the temperature of return water and outlet water is normal;



(5) Check whether the sound and current of water pump operate normally;



(6) Check whether the valve can be opened flexibly, whether there is rust or leakage;



(7) Check the insulation system for cracks, damage, water leakage and other phenomena.


3、 Regular return visit for maintenance of central air conditioning system


(1) Ask the engineering staff to know whether the equipment and system are in good condition in the near future;


(2) Check the operation records of equipment and system, and judge whether there is any fault.


4、 Maintenance contents of central air conditioner


1. Maintenance in normal operation


(1) Check the oil pressure and oil quantity of compressor refrigeration oil;


(2) System leakage detection (refrigerant), leakage points found in time to deal with;


(3) Check for abnormal sound, vibration and high temperature;


(4) Check the temperature and pressure of condenser and cooler;


(5) Check whether all kinds of valves are normal;


(6) Check the temperature and pressure of water in and out of the chiller;


(7) Check and compact the terminals on the main circuit;


(8) Check the electrical control part;


(9) Check the lubrication system of the unit;


(10) Check the working state of all instruments and controllers;


(11) Keep the equipment clean.


2. Maintenance after annual shutdown


(1) Check and clean the drying filter. Desiccant should be dried or replaced after moisture absorption;


(2) Check the setting value of safety protection device of refrigeration equipment;


(3) Check the oil pressure and oil quantity of compressor refrigeration oil, and replace and supplement the refrigeration oil if necessary;


(4) Check the insulation of compressor motor;


(5) Check and tighten the wire contacts on the circuit;


(6) Check the electrical control part;


(7) Provide the above inspection report (once a year).


3. Terminal maintenance


(1) Inspection of air handling unit and fan coil unit (once a year).


(2) Maintenance and refueling of air handling unit and fan coil unit (once a year).


(3) Check and adjust belt, clean surface cooler and filter (at least once a year).


(4) Clean the pipeline and decontaminate (at least once a year).


(5) Cleaning and dedusting of air handling unit (once a year).


4. Maintenance of water system


(1) Inspection and refueling of chilled water pump and cooling water pump;


(2) Motor, electrical insulation testing, refueling, inspection and replacement of sealing elements;


(3) General maintenance overhaul of cooling tower;


(4) Inspection, replacement and repair of valves, filters, one-way valves, pressure gauges, thermometers and thermal insulation of key parts of water system.


5. Maintenance of cooling tower


(1) Maintenance of cooling tower packing, cleaning and replacement;


(2) Repair cooling tower steel parts, cleaning, anti-corrosion and replacement;

(3) Repair, clean, repair and replace the FRP parts of cooling tower;


(4) Maintenance cooling tower fan, motor maintenance, reducer maintenance, repair and replacement;


(5) Maintenance of cooling tower fan static balance, adjustment;


(6) Maintenance, repair and replacement of water distributor and water distribution pipe of round tower;


(7) Maintenance, repair and replacement of spray nozzle and water collector of square tower;


(8) Maintenance, cleaning and maintenance of cooling tower sump and circulating water pipeline;


(9) Removal of cooling tower;


(10) Maintenance and reconstruction of cooling tower structure;


(11) Thermal performance upgrading of cooling tower;


(12) Noise and vibration maintenance of cooling tower.


6. Precautions for maintenance of cooling tower:


(1) The V-belt of the forced draft fan may stretch slightly during the initial operation. Please adjust the belt tightness according to the adjustment essentials. If the belt is too tight, the bearing will be damaged and an accident will occur.


(2) Regularly clean the upper water tank apron, lower water tank filter, etc.


(3) When the cooling tower stops for a long time, loosen the belt and cover the motor. During operation, the belt and locking nut shall be fixed, and the bird's nest or foreign matter in the cooling tower shall be checked. Then start the machine again.


(4) Exchange circulating water more than once a month. (in closed situation, the circulating water does not need to be exchanged, but the dispersed water needs to be exchanged).


7. Precautions for cooling tower operation in winter:


(1) When the cooling tower is stagnant, pay attention to discharge the circulating water and the water in the water distributor to avoid damage.


(2) For closed cooling tower, please open the drain valve of circulating water drainage, exhaust port and apron water pump.


(3) In order to prevent the water tank under the cooling tower from freezing, the anti freezing electric heater should be used when the temperature is low.


8. Precautions for closed cooling tower in winter:


(1) Attention should be paid to prevent the freezing of copper tube (radiator) and dispersed water in the closed cooling tower in winter.


(2) In order to prevent the cooling tower circulating water from freezing, please add non freezing liquid in the circulating water or add auxiliary anti freezing electric heater in the piping.


(3) After adding antifreeze to the cooling tower, the freezing temperature drops and it is not easy to freeze. The higher the concentration of antifreeze, the lower the freezing temperature, but the lower the thermal conductivity. Therefore, attention should be paid when using the cooling tower. When the cooling tower has water leakage or natural loss, the make-up water will dilute the unfrozen liquid and increase the freezing temperature. Please pay attention to the water temperature.


(4) When the circulating water pump of the cooling tower is running, the anti freezing electric heater will heat up, and the water will not freeze. If the circulating water pump stops, it is necessary to use auxiliary circulating water pump. Here, we suggest to use a complete set of antifreeze (including auxiliary circulating water pump, anti freezing electric heater, piping).


(5) The circulating water system is equipped with a 3-way valve. When the circulating water is controlled by the bypass pipe, if the flow rate of the bypass pipe is increased, the flow rate in the copper pipe will be reduced, even if there is a load, freezing may occur. Please set the cooling tower * small circulating water volume.


(6) In order to prevent the water pump and pipe from freezing, please use the anti freezing electric heater to keep the temperature of the lower water tank.