Refrigeration – Processes – Evaporation induced by sorption
Patent
1995-09-05
1997-10-07
Doerrler, William
Refrigeration
Processes
Evaporation induced by sorption
62476, F25B 1500
Patent
active
056735669
DESCRIPTION:
BRIEF SUMMARY
The invention relates to heat pump and refrigeration systems and in particular to a reversible heat pump and refrigeration system which is combined with an injector, ejector or jet pump, hereinafter referred to as elector.
The environmental case for using heat operated refrigeration and heat pump cycles instead of vapour compression types is strong. For example, some more complex, ie multiple-effect absorption refrigerators typically used in air conditioning applications are reported to have effective coefficient of performance (COP) values, (in terms of primary energy consumption), approaching 1.5, whereas vapour compression systems, powered by mains electricity, seldom have effective COP values greater than 0.9 when the inefficiencies of electrical power supply are taken into account. A comparison of these COP values indicates the potential for a 70% reduction in CO.sub.2 emissions is possible by changing over to absorption refrigerators. This is in addition to the potential environmental benefits of using environmentally friendlier refrigerants, such as water.
Unfortunately, less complex, ie single-effect absorption refrigerators tend to be less efficient than either of those described above. For example, they tend to have a COP in the region of 0.4-0.45. Their performance is therefore less than multiple-effect absorption refrigerators and vapour compression refrigerators. Moreover, they also tend to be more costly in terms of capital investment per kW of cooling.
One important application of refrigeration and heat pumping is in building air conditioning. At this time there is an increasing trend away from at large centralized refrigeration plant for both economic and environmental control reasons. This trend is recognized by the increasing sales success of split, multi-split and Variable Refrigerant Volume (VRV) systems, all of which include small mains powered vapour compression refrigerators. The vast majority of systems sold have cooling capacities of less than 30 kW. However, at this time, absorption refrigerator units are generally only available with cooling capacities ranging from 300 kW to 6000 kW.
The need for a cost effective and efficient absorption refrigerator in the small capacity range is recognized. However, the small scale refrigerator market is particularly price sensitive and very competitive. Further research into heat powered refrigerator technology is required if efficient and cost effective units are to become widely available and the environmental benefits realized.
Our aims for the future development of refrigeration machines must include a cessation to the use of synthetic refrigerant fluids, such as CFC, HCFC and HFC refrigerants, and also significant cuts in CO.sub.2 emissions associated with operating refrigeration equipment. One way to achieve these aims is to encourage users of refrigeration equipment to select heat powered refrigerator options, as opposed to vapour compression options.
We therefore want to provide a heat pump and refrigeration system which is adapted so that the load on the absorber in reduced.
It is known to provide heat pump and refrigeration systems which include an ejector, which is arranged so as to be upstream of a condenser. For example, U.S. Pat. No. 4,290,273 describes such a system but it is of note that the ejector is not used for the purpose of extracting refrigerant vapour from the evaporator and so reducing the demands of the absorber so as to increase the efficiency of the system. On the contrary, the provision of an ejector has no effect on the load on the absorber and therefore the relative positioning of the ejector in the system described in this patent document is of no relevance to the subject matter of this invention.
Similarly, U.S. Pat. No. 3,440,832 also described a system incorporating an ejector, which ejector is position upstream of the condenser. However, this document similarly does not address how to reduce the load on an absorber but rather it tends to teach away from the invention described in this application in that it
REFERENCES:
patent: 1615353 (1927-01-01), Altenkirch
patent: 1934690 (1933-11-01), Babcock
patent: 2014701 (1935-09-01), Seligmann
patent: 2446988 (1948-08-01), Flukes et al.
patent: 3167929 (1965-02-01), Rorschach
patent: 3402570 (1968-09-01), Schlichtig
patent: 3440832 (1969-04-01), Aronson
patent: 3638452 (1972-02-01), Kruggel
patent: 4248049 (1981-02-01), Briley
patent: 4270365 (1981-06-01), Sampietro
patent: 4285211 (1981-08-01), Clark
patent: 4290273 (1981-09-01), Meckler
patent: 4301662 (1981-11-01), Whitnah
patent: 4311024 (1982-01-01), Itoh et al.
patent: 4374467 (1983-02-01), Briley
patent: 4474025 (1984-10-01), Alefeld
Aphornratana Satha
Eames Ian William
Doerrler William
The University of Sheffield
LandOfFree
Absorption refrigerators does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Absorption refrigerators, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Absorption refrigerators will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2348816