Heat exchange – Flow passages for two confined fluids – Interdigitated plural first and plural second fluid passages
Patent
1994-11-10
1996-07-02
Leo, Leonard R.
Heat exchange
Flow passages for two confined fluids
Interdigitated plural first and plural second fluid passages
165DIG364, F28F 308
Patent
active
055312691
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a plate heat exchanger for heat transfer between two fluids having different flow volumes, comprising several principally rectangular heat transfer plates, each having inlet and outlet openings for respective fluids through its corner portions, a heat transfer portion, located centrally between respective inlet and outlet openings, and two distribution portions, located between the heat transfer portion and respective inlet and outlet openings, and being formed for distribution of the respective two fluids, when these flow from their inlet openings towards the heat transfer portions.
Traditionally formed plate heat exchangers usually have a package of identical heat transfer plates, which have inlet and outlet openings of the same kind for both of the fluids. Such a heat exchanger, having inlet and outlet openings of the same kind, is optimally used only with equal flow volume of both of the fluids. If one of the fluids has a smaller flow through the heat exchanger than the other fluid, the pressure drops of the fluids will be different, because the pressure drops alter proportionally with the square of the volume flow. This means, that the heat transfer between the fluids and the heat transfer plates cannot become optimal on both sides of each heat transfer plate, if the flows of the fluids differ.
To increase the heat transfer, in connection with a so called unsymmetrical flow between the heat exchanging fluids, it has previously been proposed to decrease the volume of the flow ducts on one side of the heat transfer plates, as disclosed in EP 470 073, or to influence the flow resistance of the flow ducts by a combination of different corrugation pattern of the heat transfer plates, as disclosed in EP 88 316 or EP 204 880. These previously proposed arrangements have in common that they only admit a small unsymmetrical flow between the two fluids and that the heat transfer regarding the heat transfer plates would not become sufficiently effective for both fluids.
An object of the present invention is to achieve an improved heat transfer between two fluids having different flow volumes in a plate heat exchanger of the described kind. An additional object is to provide a plate heat exchanger, which admits a larger unsymmetrical flow between the two fluids of different flow, compared to previously known plate heat exchangers.
These objects are attained according to the invention in that the size of the inlet and outlet openings of the heat transfer plates for a first of said two fluids is smaller than the size of the inlet and outlet openings for the other fluid, and in that the heat transfer plates in their distribution portions are so formed that the flow resistance of the first fluid, flowing between the inlet and outlet openings of first fluid and the heat transfer portions, is larger than the flow resistance of the other fluid, flowing between the inlet and outlet openings of the other fluid and the heat transfer portions.
The present invention aims at equally large pressure drops on both sides of the heat transfer plates, despite that the flows of the two heat exchanging fluids are different. Thus, for instance the flow condition of the first fluid, i.e. the fluid having the smallest flow, is optimized with respect to the heat transfer, simultaneously as the flow is simplified for the other fluid, i.e. the fluid having largest flow.
Preferable, the flow resistance can be made larger for the first fluid than for the other fluid, by making a longer flow path, at each distribution portion, for the first fluid than for the other fluid.
Also, by forming the distribution portion in such way, that the total width of the flow becomes smaller for the first fluid than for the other fluid, one can make the flow resistance larger for the first fluid than for the other fluid.
The flow resistance of the two fluids can also be made unequal, by designing the pressing pattern in the distribution portions of the heat transfer plates with smaller pressing depth on one side than on the othe
REFERENCES:
patent: 2623736 (1952-12-01), Hytte
patent: 3661203 (1972-05-01), Mesher
patent: 3783090 (1974-01-01), Andersson et al.
patent: 3817324 (1974-06-01), Andersson
patent: 4176713 (1979-12-01), Fisher
patent: 4376460 (1983-03-01), Skoog
patent: 4572766 (1986-02-01), Dimitriou
patent: 4605060 (1986-08-01), Andersson et al.
patent: 4781248 (1988-11-01), Pfeiffer
patent: 4911235 (1990-03-01), Andersson et al.
patent: 4915165 (1990-04-01), Dahlgren et al.
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