Abstract
An internal melt ice thermal storage device having an ice build/melt coils with tubes fitted with extensions or fins that transfer heat from the thermal transfer medium in the tubes to distal portions of the ice rings that surround said tubes in order to define the shape of the liquid meniscus between the tube and ice allowing the ice to break free from the tube near the initiation of melt.
Claims
1. An internal melt thermal ice storage device comprising: an ice build/melt coil mounted in an ice water tank configured to hold a thermal storage medium, said ice build/melt coil having a thermal transfer medium input end and a thermal transfer medium output end, both of which are connected to a thermal transfer medium source; said ice build/melt coil comprising a plurality of tubes, wherein one or more of said tubes bear ice breaker projections configured to transmit heat from a thermal transfer medium circulating in said tubes to distal areas of an ice ring surrounding said tube thereby defining a shape of a liquid meniscus surrounding said tube and said ice breaker projections during a melt cycle of said internal melt thermal ice storage system; wherein each said tube has a first fin extending vertically up from a top exterior surface of said tube and a second fin extending vertically down from a bottom exterior surface of said tube, and wherein said first and second fins run along a longitudinal length of said tube.
2. The device according to claim 1, wherein said tubes have an oval shape with a vertically oriented major axis.
3. The device according to claim 1, wherein each said tube has a third fin extending away from an exterior surface of said tube and running along a longitudinal length of said tube, wherein said first, second and third fins are spaced equally about said tube.
4. The device according to claim 1, wherein each said tube has a third fin extending away from an exterior surface of said tube and running along a longitudinal length of said tube, wherein said first, second and third fins are spaced unequally about said tube.
5. The device according to claim 1, wherein said thermal storage medium is water.
6. The device according to claim 1, wherein said thermal transfer medium is glycol.
Description
DESCRIPTION OF THE DRAWINGS
(1) The subsequent description of the preferred embodiments of the present invention refers to the attached drawings, wherein:
(2) FIG. 1 is a schematic showing the major components of a thermal ice storage coil.
(3) FIG. 2 shows an outside perspective view of a standard ice coil tube.
(4) FIG. 3 shows a cross-sectional view of a standard ice coil tube.
(5) FIGS. 4a through 4d show the progression of melt of a standard ice coil.
(6) FIG. 5 shows an outside perspective view of an ice breaker tube according to an embodiment of the invention.
(7) FIG. 6 shows a cross-sectional view of an ice breaker tube according to the embodiment of FIG. 5.
(8) FIGS. 7a through 7c show the progression of melt with an ice breaker tube according to the embodiment shown in FIGS. 5 and 6.
(9) FIG. 8 shows a thermal ice storage coil using tubes with projections according to the invention.
(10) FIG. 9 is a cutaway close-up view of a thermal ice storage coil according to an embodiment of the invention, during a melt phase, showing ice separated from the tubes but constrained from floating by adjacent structures.
(11) FIG. 10 is another view of the embodiment of claim 9, showing hidden structures in dashed lines.
(12) FIG. 11 shows ice breaker tubes according to six different embodiments.
(13) FIG. 12 shows relative glycol supply temperature performance of the a prior art ice coil tube in an internal melt ice coil as compared to an ice breaker tube according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
(14) FIG. 1 shows the major components of a prior art internal melt ice coil system in cross section. Ice water tank 1 holds a plurality of tubes 3 filled with glycol. The plurality of tubes 3 is submerged in water 2. When cold glycol flows through the plurality of tubes 3, the water 2 is converted to ice 4 around the tubes 3. Detail A shows a close-up view of the tube 3 and ice 4 with its melt direction 5 away from the tube surface.
(15) FIG. 2 illustrates an isometric view of a prior art ice coil tube.
(16) FIG. 3 shows a cross section of the tube in FIG. 2. In use, the tube 3 surrounds a glycol solution 6.
(17) FIG. 4a shows an ice coil tube with ice build in cross section. An ice coil tube 3 is filled with a cold glycol solution 6 that has previously built a layer of ice 10 around the tube 3.
(18) FIG. 4b shows an ice coil tube with ice first starting to melt. Tube 3 contains a warm glycol solution which has initiated heating of the tube. A meniscus of water 12 forms as the ice 10 begins to melt.
(19) FIG. 4c shows an ice coil tube well into the melt cycle. At this point the meniscus of water 12 is large but has not penetrated the ice 10. During this stage, the ice 10 floats up until it touches the tube 3.
(20) FIG. 4d shows breakout of the ice. The ice 10 melts free from the tube 3 and floats. Just prior to the stage shown in 4d, the ice may also break free from the tube, but be constrained from floating as it is held by its distal/bottom ends.
(21) FIG. 5 shows an isometric view of an ice breaker tube according to an embodiment of the invention, having a generally oval-shaped tube fitted with projections or fins extending from the top and bottom of the tube.
(22) FIG. 6 shows the main components of the ice breaker tube embodiment of FIG. 5 in cross section. Tube 21 is filled with glycol 19. Projections 20a and 20b connect to the tube 21. The projections may be fixed to the tube according to any known manner, including integrally cast with the tube, welded to the tube, etc.
(23) FIG. 7a shows a cross section of an ice breaker tube according to an embodiment of the invention in which ice has formed and before ice melt begins. Tube 21 is filled with cold glycol 22 which has previously formed ice 24. Projections 20a and 20b pass to the outside of the ice into the water surrounding the ice.
(24) FIG. 7b shows the embodiment of the ice breaker tube of FIG. 7a at the initiation of melt. The water meniscus around the tube projects to the outside of the ice 24 in channel 28.
(25) FIG. 7c shows breakout of the ice. Tube 21 is in contact with the bulk water in the tank as ice 24a and 24b float free of the tube 21.
(26) FIG. 8 shows a thermal ice storage coil using tubes with projections according to the invention. Ice water tank 1 holds a plurality of tubes 21 filled with glycol, which tubes are fitted with projections 20a and 20b. The plurality of tubes 21 is submerged in water 2. When cold glycol flows through the plurality of tubes 21, the water 2 is converted to ice 24 around the tubes 21. Detail A shows a close-up view of the tube 21 and ice 24 with its melt direction 5 away from the tube and projection surfaces.
(27) FIG. 9 is a cutaway close-up view of a thermal ice storage coil according to an embodiment of the invention, during a melt phase, showing ice separated from the tubes but constrained from floating by adjacent structures.
(28) FIG. 10 is another view of the embodiment of claim 9, showing hidden structures in dashed lines. As can be seen from FIGS. 9 and 10, even though the ice is separated from the tube by the meniscus, the ice is initially constrained from moving to the surface of the water in the tank by adjacent tubes, ice pieces, and the ends and sides of the tank.
(29) FIG. 11 shows alternative embodiments of ice breaker tubes according to the invention. According to alternative embodiments of the invention, the tube may be provided with two extensions, three extensions, four extensions, five extensions (not shown), six extensions (not shown), seven extensions (not shown), eight extensions, or more, in order to accelerate ice breakout from the tube. According to various embodiments, the extensions may be distributed equally or unequally around the tube, and asymmetrically or symmetrically around the tube. The tube itself may be round, oval, or extended oval in shape.
(30) FIG. 12 is a chart plotting the temperature of the glycol supply circulating through the coil versus percentage of ice melted during a melt cycle for an ice coil with prior art ice coil tubes and for an ice coil with ice breaker tubes according to the present invention, in particular the embodiment shown in FIGS. 5 and 6. As shown in the chart, the temperature of the glycol supply with the prior art ice coil has a much higher average temperature, and fluctuates significantly, as compared to the temperature of the glycol supply in the ice coil with the ice breaker tubes of the present invention. Accordingly, the present invention provides more effective and more efficient cooling with little additional capital expenditure.
