Refrigeration – With internal-combustion engine
Patent
1986-07-17
1988-10-11
Capossela, Ronald C.
Refrigeration
With internal-combustion engine
62376, 126 195, F25B 2700
Patent
active
047761814
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for transferring heat from one liquid to another, to heat exchangers for performing the method, and particularly to such exchangers wherein the coolant is passed through a network of conduction passages across which a cooling medium is passed.
2. Description of the Prior Art
Hitherto, water cooled heat exchangers operating at temperatures below 100.degree. C. at atmospheric pressure and in temperate ambient conditions suffer the shortcoming of poor effiency due to the low heat gradient between the coolant such as flows through an engine and the cooling medium. In the past this problem has been overcome by one of, or a combination of two methods.
In a first method the flow rate of the cooling medium across to the passages is increased. The problems associated with this solution are two-fold. Firstly, increased energy is required to pump the cooling medium across the passages and secondly, a greater amount of cooling medium is required. This can be a particular problem in closed cycle, fluid cooling medium systems.
In a second method the length of passage is increased, increasing the contact area between the coolant and the cooling medium. The problems associated with this method are increased cost of manufacture and increased required coolant pump capacity to overcome the frictional losses incurred in the increased passage length.
It is an object of the present invention to provide a method and apparatus able to avoid or at least ameliorate the above listed shortcomings by utilizing latent heat of vaporization to assist in the cooling process, the boiling point of the cooling medium being reduced below the temperature of the coolant by reducing the pressure of the cooling medium.
SUMMARY OF THE INVENTION
According to the first aspect the invention consists in a method of transferring heat from a first fluid to a second, the temperature of the first being less than the boiling point of the second at ambient pressure, comprising the steps of:
causing the fluids to come into heat flow communication; and,
reducing the pressure of the second fluid so that it boils at or below the temperature of the first.
According to a second aspect the invention consists in a heat exchanger for performing the method comprising:
a pressure vessel;
at least one tube for conducting a fluid into, within, and out of the vessel;
means for admitting a cooling medium to the vessel, and directing it over the exterior surface of the tube within the vessel;
means for removing the cooling medium from the vessel after contact with the tube; and
means for reducing pressure in the vessel whereby to lower the temperature of evaporation of the cooling medium.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the apparatus of the present invention will now be described by way of example only, with reference to the accompanying drawings in which:
FIG. 1 is a schematic representation of a heat exchanger according to the invention;
FIG. 2 is a schematic side elevation of a desalination plant incorporating the heat exchanger of FIG. 1;
FIG. 3 is a schematic end elevation of the plant of FIG. 2; and
FIG. 4 is a schematic view of a combustion engine constituting a heat source for the plant of FIGS. 2 and 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1 a heat exchanger 1 is shown, which was developed to cool the engine cooling water (coolant) from a "Caterpillar 398G" by 5.degree. C. from 85.degree. C. to 80.degree. C.; both of which are below the boiling point of water at sea level atmospheric pressure, with the cooling medium at 20.degree..
The heat exchanger 1 comprises a pressure vessel 2 and a plurality of tubes 3 housed within the pressure vessel 2.
Coolant inlet ports 4 and coolant outlet ports 5 are provided on the respective ends of tubes 3 and extend into the pressure vessel 2. The tubes 3 are adapted to conduct the coolant from the engine (not shown) through the pressure vessel 2.
The tube 3 may be in the
REFERENCES:
patent: 3344041 (1967-09-01), Wulfson
patent: 3344584 (1967-10-01), Kehoe et al.
patent: 3528890 (1970-09-01), Brown
patent: 3597164 (1971-08-01), Ab-Der-Halden
patent: 3675436 (1972-07-01), Ganiaris
patent: 3732690 (1973-05-01), Meijer
patent: 3844132 (1974-10-01), Miller et al.
patent: 4144849 (1979-03-01), Dahm
Capossela Ronald C.
Salfon Pty. Ltd.
LandOfFree
Evaporative heat exchanger does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Evaporative heat exchanger, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evaporative heat exchanger will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1950595