In the last article, we thought a bit about the effect water has on ammonia when they are mixed, and it was noted that ammonia refrigeration systems have been known to carry on working even when as much as 25% of the liquid in the system is water. The effect of the water is to move the boiling point of the ammonia, so that in an evaporator the temperature shifts as the liquid turns to gas.
It is important to remember that when air leaks into a refrigeration system it brings other stuff with it. Like an onion, the other stuff is mostly water. In fact, every 9 lbs (4 kg) of air that get into a system bring 1 oz (30 mL) of water with them. This doesn’t sound like a lot, but when you purge the air out of the system it leaves the water behind so over weeks and months it can build up.
This article is the 12th in a series exploring refrigeration and heat pump concepts without using jargon. Last time we considered the effect of air or nitrogen in a condenser. Now, it’s time to consider some effective — and not so effective — strategies for overcoming this problem.
It is now time to dig a little deeper into the jargon, although you should bear in mind that it is theoretically possible to talk about refrigeration systems without using any jargon at all. Fridge guys are generally not good at this; they have a language of their own and they are not ashamed to use it.
This article is the ninth in a series exploring refrigeration and heat pump concepts without using jargon. Last month we started looking at the unsavory side of refrigeration. This continues with a sideways look at lubricating oil.
This article is the eighth in a series exploring refrigeration and heat pump concepts without using jargon. We start to look at some of the unsavory things that creep into refrigeration plants. The first of these is the defrost cycle.
This column is the sixth in a series exploring refrigeration and heat pump concepts without using jargon. Previously in this series, we thought about efficiency being defined as “what you want to do” divided by “what you need to do.” For example, a beer maker would measure his efficiency in “beers per kWh.” A corollary of this definition is that inefficiency occurs when, in addition to doing what you want to do, you are unwittingly doing a whole bunch of other things as well. These other things will consume additional resources and so will make the plant less efficient than it should be.