Absorption Refrigeration
Absorption Refrigeration
(OP)
Can somebody tell me please why I should not use an absorption type refrigeration for room cooling as against the conventional vapor compression system.
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RE: Absorption Refrigeration
By the way, I do actually run a couple of absorption chillers myself (each about 800 TonR capacity), but that's only because I get "cheap" steam from a combined heat and power system.
Brian
RE: Absorption Refrigeration
Until and unless I have cheap steam I won't disagree
Olmedo!
The basic advantage of absorption system was (or is?) conversion of low grade energy to low grade energy. Generally electrcity is considered as high grade energy and heat as low grade energy. Conversion from high grade energy to a low grade energy is a loss. Though COP of absorption machines are almost one third that of compression machines, the net work input will be less incase of absorption system.
Some of the disadvantages
1. On LiBr-Water system, you cannot go below 50C chilled water temperature with the best attainable vacuum.
2. Crystallization of LiBr strong solution is a deadly problem at lower cooling water temperatures.
3. Periodic treatment and cleaning of LiBr is required.
4. Not a stand alone system. Even steam generator failure contributes to chiller downtime.
5. Foot print area is more for same capacity.
6. Not very flexible with load variations. (capacity control is not very good. (Liquid bypass from evaporator to absorber is a common practice. This shows the inefficiency of capacity control)
7. One point where I think Brian will agree with me is that, we should spend more time with an absorption machine when compared to relatively trouble free compression machine.
Regards,
RE: Absorption Refrigeration
$406,800 for electric centrifugal
$786,000 for gas fired absorption
$509,000 for steam absorption
RE: Absorption Refrigeration
You will also need to have a bigger cooling tower, since the approximate factor for heat rejection calculation would be about 1.85 as against 1.25 normally used for vapour compression machines.
If you were to use HSD as fuel for generating steam, then the additional hassles of "Explosive licences", storage of diesel, etc., etc.
RE: Absorption Refrigeration
In saying this though, i have seen major energy savings in steam turnbine to electric power plants where the waste heat from the turbines drives absorpers that chill the air entering the turbines and therefore increase the efficiency of the turbines considerably. Also, there are a lot of Absorption machines used in geothermal areas where natural reserves of high pressure steam/hot water can be utilised by large wood pulp processors and the low pressure steam left at the end of the process can be used to drive absorbers to meet all of the process cooling requirements
cheers
kiwicam
RE: Absorption Refrigeration
RE: Absorption Refrigeration