9/17/2015

Maintenance Considerations of Water Chillers chiller trane party 2

Maintenance Considerations
of Water Chillers chiller trane
party 2

Maintenance Water Chillers chiller trane


Other design-specific requirements:
Other design-specific requirements

◆    Change oil when oil analysis dictates
◆    Replace oil filter periodically
◆    Replace filter drier periodically
◆    Clean oil strainers annually
◆    Check shaft alignment annually
◆    Check coupling annually
◆    Replace shaft seal every 2 to 4 years
◆    Compressor teardown inspection every 5 to 10 years


Some helical-rotary compressor designs do require periodic maintenance of mechanical system components. This includes oil and refrigerant filter changes, oil strainer changes, and a compressor rotor inspection.
Open-motor compressor designs require shaft alignment, coupling inspection, bearing lubrication, and cleaning of the motor windings, rotor ends, and fan blades on a quarterly or annual basis.
In all cases, strictly follow the manufacturer’s published maintenance requirements and recommendations.
Recommended maintenance:
Recommended maintenance
◆    Use a qualified water treatment specialist
◆    Clean condenser tubes as needed (water-cooled)
◆    Clean water-side strainers
◆    Test tubes every 3 years
◆    Clean condenser coils as needed (air-cooled)
Optimum performance of heat transfer components depends on keeping the heat transfer surfaces free from scale and sludge. Even a very thin deposit of scale can substantially reduce heat transfer capacity. Owners of water-cooled chillers should engage the services of a qualified water treatment specialist to determine the level of water treatment required to remove contaminants from the cooling tower water.
Scale deposits are best removed by chemical means. The water-cooled condenser is commonly isolated from the rest of the cooling tower water circuit by valves, and a pump circulates cleaning solution through the condenser tubes.
Sludge is removed mechanically. This involves removing the water boxes from the condenser and loosening the deposits with a stiff-bristled brush. The loosened material is then flushed from the tubes with clear water. As part of this procedure, the strainers on both the chilled water and cooling tower water circuits should be cleaned every year.
Every 3 years, or more frequently for process or critical applications, it is recommended that a qualified service organization perform non-destructive tube inspections on both the evaporator and condenser tubes. The eddy- current tube test is a common method.
Rarely, problems may arise that cause refrigerant or water leaks. These must be repaired immediately.
For air-cooled chillers, the condenser coils should be cleaned at least annually in order to maintain proper efficiencies and operating conditions. Follow the manufacturer’s instructions to avoid damage to the coils.

Fluid Analysis:

\Fluid Analysis

▲ Oil analysis
◆    Conduct annual analysis to verify system integrity
◆    Measure oil pressure drop to determine if filter needs changing
◆    Measure charge
▲ Refrigerant charge
◆    Measure charge and trim as necessary
◆    Measure superheat and subcooling

Probably the most important annual maintenance task required for helical- rotary water chillers is an oil analysis. It may be conducted more frequently for chillers that run continuously or more often than normal. This test, performed by a qualified laboratory, verifies the integrity of the refrigeration system by testing the moisture, acidity, and metal concentration levels. This analysis can determine where problems exist or could potentially develop. By taking oil samples on a regular basis, normal operating trends for the compressor and bearing metals can be analyzed. As opposed to changing the oil once a year whether it needs it or not, regular oil analyses can be used to determine proper oil change intervals as well as predict major problems before they occur.
Refrigerant analysis measures contamination levels and determines suitability for continued use. It can also determine the acceptability of recycled refrigerant for reuse. Refrigerant analysis helps extend the life of the existing charge and ensures that the chiller is operating at peak efficiency.
Logging the oil and refrigerant charges, and examining the trends of this data, can help identify potential problems before they occur.

Fluid Analysis:
Fluid Analysis2

▲ Why perform regular oil analyses?
◆    Helps reduce maintenance costs
◆    Detects problems without compressor disassembly
◆    Extends service life of oil charge
◆    Reduces environmental problems related to oil disposal
◆    Helps maintain compressor efficiency and reliability
◆    Helps lower refrigerant emissions


An oil analysis is a key preventive maintenance measure and should be conducted at least annually. It will help the compressor last longer while improving chiller efficiency and reducing refrigerant emissions. A certified chemical laboratory has years of experience in analyzing oil and refrigerant from all types of compressors.
Often the chiller manufacturer can provide this service.


                                    younes kandi

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