September, 2012
All experts are well familiar with the method of building up a refrigeration supply system using a secondary circuit with a circulating intermediate cooling medium.
Let us review some practical aspects
Mainly a system consists of two integral parts — equipment and a cooling medium circulating through it. At the beginning of operation both of them are new but as time moves on equipment ages and cooling medium deteriorates, some accidents happen at production, and this leads to the necessity to evaluate the overall picture.
For a start we will give some definitions:
- A new cooling medium is a qualitative cooling medium that was not in operation and has unexpired shelf life.
- New equipment is equipment that has not been in operation yet.
- An old cooling medium is a cooling medium that has been in operation and/or has expired shelf life.
- Old equipment is equipment that was in operation.
We offer to our honourable reader the review of some common situations
New cooling medium in the new equipment
The most clear option. We should note that it is necessary to wash out the entire system after assembling and before filling it with a cooling medium in order to prevent introduction of dirt, grease, slag and etc. If necessary a system is washed both with plain water and with chemical agents. You should remove all washing fluid and collected dirt from a system after washing process.
Old cooling medium in the new equipment
Quite a rare case. We recommend to inspect characteristics of a cooling medium thoroughly before making a decision on whether it is worth to be filled in a new expensive equipment or not. If an old cooling medium cannot be cleared by filtration, settlement and treatment with other simple methods, then it is unreasonable to use it.
New cooling medium in the old equipment
This case often appears when an old cooling medium is changed to a new one. A new cooling medium can be equal to an old one with expired date or can have another base, as in a case of changing of brine with propylene glycol. In both cases it is critically necessary to conduct full cleanup from different deposits accumulated during operation process. There is a vast amount of various methods and agents for cleanup of equipment. A cleaning scheme should be designed for each case individually to obtain optimal result.
Old cooling medium in old equipment: problems
A cost-effective option when there is no money for reorganization but interference is needed. It is necessary to clean equipment (as mentioned above) and also clean and correct a cooling medium.
In order to execute such operations you have to stop a system temporary. You have to drain a cooling medium in reserve vessels, analyze it and make a decision on its further usage. Equipment has to be cleaned, washed and repaired. After completion of works with a cooling medium and equipment, the latter is filled up with the first one. The best choice is to execute scheduled maintenance of operated equipment. Along with that, labour, material and temporary costs to be optimized.
Old cooling medium in the old equipment: no problems
Probably, problems already exist, but you do not know about them. When problems arise clearly we recommend you to read the previous chapter.
But we will rely on the better variant: the system is operated for not a long time, there are no problems, you just want to have it all under your control and take immediate actions if necessary. In this situation you should execute scheduled monitoring of equipment and cooling medium operated in it. You can get a piece of advice on equipment check-up from professionals who mounted your system.
Monitoring of a cooling medium is a scheduled check-up of its main operating characteristics. Changes in characteristics give a pretty clear picture on what is going on in your system. This type of control does not require much time and costs but allows to detect and remove majority of problems on the stage of their arousal.