Maintien de l'intégrité mécanique des condenseurs évaporatifs

Par Stephen G. Kline, P.E., M.B.A., BAC

Evaporative condensers are an efficient and cost-effective heat rejection solution for various applications—food and beverage refrigeration, industrial machinery cooling, and HVAC. The units work by condensing superheated refrigerant vapor inside a coil that is continually sprayed with water. As the water evaporates, fans reject the heated water vapor to the atmosphere. By lowering system condensing temperatures, evaporative condensers reduce compressor horsepower requirements, resulting in energy savings of up to 15% when compared to air-cooled systems.

A comprehensive program of routine preventive maintenance will keep refrigeration systems performing at peak efficiency, maximize system operating life, and reduce unplanned downtime due to equipment failure. It also helps to ensure reliable and safe operation, which is critically important to avoid leakage of ammonia and other refrigerants. Regular inspections are, of course, key and should be done in accordance with the manufacturer’s recommendations and plant preventative maintenance schedule.  Below are general guidelines for the areas of inspection that should be part of any effective evaporative condenser preventive maintenance program. These guidelines cover inspections in 10 areas. Although maintenance frequency will depend on a variety of factors—e.g., condition of circulating water, cleanliness of ambient air, and the unit’s operating environment—each area of inspection should be performed at least annually and more frequently as recommended by the manufacturer for a particular component or as circumstances warrant.

For each inspection, it is important to document the inspection process and all findings, the date of the inspection, the name of the person performing the inspection, any actions taken. If any additional future actions or repairs are necessary perform per manufactures recommendations or industry standards. Digital images are a useful method for documenting present conditions and demonstrating changes over time.

To ensure worker safety, all proper lock out-tag out procedures for the unit and any site safety procedures must be followed prior to beginning inspection or maintenance work. Additionally, measures must be taken to confirm there is no refrigerant left in the coil. This is usually done by employing a vacuum system prior to entering or servicing the condenser. Always follow industry best practices regarding the use of proper PPE and “one in-one out” procedures. 

Recommended Inspection Tools

Most people carry a smartphone with a good digital camera, which is a useful tool for photographing or recording inspection findings. Other recommended tools include an infrared thermometer, an infrared camera, an ultrasonic metal thickness meter, a vibration meter (ultrasonic or accelerometer), a laser alignment tool, a multimeter for voltage and amperage, a micrometer depth gauge, and a dye penetrant test kit to detect cracks. Importantly, a complete inspection kit will also include the manufacturer’s installation, operation, and maintenance manuals and lock-out / tag out forms.

Rappelez-vous, n'attendez pas que le condenseur échoue pour effectuer l'entretien. Pour optimiser la durée de vie de votre système, la maintenance préventive est essentielle. Un équipement bien entretenu maximisera la disponibilité et l'efficacité et contribuera à maintenir l'hygiène et la sécurité de votre système.