Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24V—COLLECTION, PRODUCTION OR USE OF HEAT NOT OTHERWISE PROVIDED FOR
  • F24V50/00—Use of heat from natural sources, e.g. from the sea
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S20/00—Solar heat collectors specially adapted for particular uses or environments
  • F24S20/40—Solar heat collectors combined with other heat sources, e.g. using electrical heating or heat from ambient air
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/40—Solar thermal energy, e.g. solar towers

Definitions

• the present invention relates to a method of recovering the energy made available when water freezes.
• Such energy can be recovered by means of collectors, so-called heat receivers, for heat pump systems. This is explained in more detail in the Swedish patent application No. 8201039-8.
• the condensed water will freeze to ice on the surface of the collector and a further phase conversion then can be utilized.
• 336 kJ/kg water are made available, which should be conferred with about 4.2 kJ/kg that can be recovered when lowering the temperature of water by 1 C.
• the heat receivers which operate with the outside air as the heat source, are not constructed such that the ice formation energy provides an energy supply, because the ice must be removed rapidly by thermal de-icing. The energy that possibly has been received at the ice formation, then will be consumed for the removal of the ice from the surface of the receiver. Otherwise the admission of the air will be obstructed and the power delivery will be reduced.
• the porosity of the collector screen is large and the admission of the air is not obstructed notwithstanding heavy ice formation on the several surfaces of the collector. Accordingly, heat will be exchanged through an ice layer, and the ice formation energy of 336 kJ/kg at the same time can be recovered.
• the temperature in the zone where the ice is being formed will be 0 C, i.e. higher than in case no ice formation had occurred. In this manner the ice formation will supply energy to the brine liquid or the fluid circulated in the collector screen.
• the heat receiver therefore can absorb the heat energy at a higher temperature than that corresponding solely to the air temperature.
• an ice collector body is a good receiver of radiated heat, direct sun radiation, and so on.
• the collector will not need specific de-icing, which is a great advantage as compared with the existing fin batteries or fan coolers. Due to the large area the air flows will always be admitted. During the shutdown periods of the heat pump, which comprise about 50% of the time at normal operation, the ice crystals will disappear and make room for new icing when the heat pump restarts.
• the ice crystals will not melt to water. On the contrary, they will sublime, i.e. they will evaporate without intervening melting. Then, the enlargement of the surface caused by the icing will be of great importance. The sublimation proceeds more rapidly when the surface is larger.
• the collector is active although the system has come to a stop.
• the generated cold thus does not affect the heat in the system; it is removed by the air flow, i.e. the wind power. Instead of de-icing in the strict meaning thereof a volatilization will take place.
• the heat pump restarts and absorbs heat from the collector screen there will again be space for repeated ice formation.
• the system will provide a good heat absorption also at bad operational conditions, such as low outside temperatures At low temperatures water is therefore sprayed through atomizing nozzles directly onto the collector body while the heat pump is operating. During the shutdown periods the water flow ceases and the ice will sublime. This is an extraordinarily effective method of utilizing the energy of water.
• the heat pump systems operating with the outside air as the heat source are dependent on de-icing means already at about +4 C due to the fact that the collector is clogged by ice which accordingly excludes the air.
• de-icing means already at about +4 C due to the fact that the collector is clogged by ice which accordingly excludes the air.
• An air temperature of about -5 C so much energy is consumed for such de-icing by means of hot gas or hot water that it is no longer worthwhile to operate the heat pump.
• Other kinds of energy then have to guarantee the heat supply, e.g. an electric element or an oil-heated furnace. In everyday speech, the energy thus supplied is called peak energy. This condition is very disadvantageous for the community, because the network for distributing electric energy will be overloaded when the outside temperature decreases and the electric elements are energized.
• Heat pumps with underground water as the heat source are considered to provide such a system. Then, water is pumped through bores to the evaporator where 4-5°C can be recovered before the water is again returned to the same depth through another bore.
• the power required for heating a house may comprise about 8 kW. This power can be obtained by allowing 62.5 1 of water to freeze so as to make 5800 W available for the heat pump system which supplies about 3000 W from the compressor heat. Alternatively, an electric element could be used for supplying the totally required power about ⁇ kW.
• the tap water shall guarantee the total peak energy, i.e. 5.8 kW. Then, 62.5 1 are required at a price of about SEK 0.006/1 (about SEK 5.50/m 3 ) at a total cost of SEK 0.38 for the 5.8 kW mentioned.
• the price of 1 kW generated by means of the invention will be SEK 0.06.
• the purpose of the invention is to make the wind screens according to the Swedish patent application No. 8000488-0 and the Swedish patent application No. 8201039-8 more effective by utilizing the heat energy available in the air which is heated close to the outside surface of a building body partly by the building body collecting large amounts of incident sun energy and partly by heat leaking from the interior of the building body in spite of an effective insulation.
• the invention it should also be possible to apply the invention to constructions which are separate from buildings, e.g. pillars or towers, poles, and so on.
• the method of the invention has obtained the characteristics appearing from claim 1.
• the method of the invention is applied most favourably in combination with a heat pump system, the heat content being utilized most effectively as a consequence thereof.
• FIG. 1 is a fragmentary side view of the screen
• FIG. 2 is a fragmentary side view of the screen with ice formation in different stages
• FIG. 3 is a fragmentary side view of the screen with heavy ice formation but with remaining apertures (porosity) for the passage of the air flow through the screen
• FIG. 4 is a side view of the screen from the outside thereof at a building body in combination with a heat pump system
• FIG. 5 is a plan view of a freely located screen construction formed as a pillar wherein the screens are interconnected in parallel, and
• FIG. 6 is a fragmentary cross-sectional view of the screen with supporting poles.
• FIG. 1 the air-permeable screen is shown.
• the apertures allowing passage of the air flow 10 are large in relation to the parts 11 and 12 of the construction having a braking effect on the air flow.
• the screen is made of aluminium or another good heat conductor. In that way the screen heat-exchanges the wind passing therethrough as described in the Swedish patent application No. 8201039-8.
• the fin surface of the screen shown in FIG. 1 is about 2.5 times larger than the area.
• Channels for the circulating heat-carrying fluid are provided in the parallel parts 11, and the interconnecting fins 12 are surface enlargers.
• the screen is shown in different ice-forming stages wherein 14 are the zones which are initially covered by ice, the zones 15 then being covered by energy-supplying ice. However, at the same time the air flow is admitted and can supply the thermal energy thereof to the different fin surfaces of the screen. A larger relative air humidity provides a larger energy supply and so does an increasing wind velocity (cfr. the diagram below). In the operational condition illustrated, the fins of the screen are still free from ice and thus can exchange heat directly to the metal. Then, it can be assumed that the surface of the screen has a temperature of at least 0 C.
• FIG. 3 the different surfaces of the screen are shown completely frosted and all energy supplied is produced in the ice formation layer or passes through said layer from the open air.
• this operational condition there is a low temperature in combination with sufficient humidity. Due to heavy ice formation when the heat pump activates the screen, the ice formation layer at low temperatures of the outside air will still hold 0°C which thus can provide a large energy supply. Under these circumstances it is possible to operate the heat pump at very low temperatures of the outside air, even if the screen primarily operates as an air collector.
• the screen 18 is shown as a heat exchanger in a heat pump system wherein the screen is located in the open air to recover energy from the surroundings.
• the heat-carrying medium 20 circulates through the screen, one half of which being connected in series with the other one.
• the heat pump 19 absorbs energy in the evaporator thereof, and by the compressor the heat energy is raised to a usable temperature level so as to be exchanged by the condenser to the radiator circuit of the object to be heated.
• the sprinkler system is synchronized with the heat-carrier pump of the system in such a way that the screen will be moistened when the rest of the system is activated.
• the moistening ceases at shutdown periods and instead the ice crystals will disappear by sublimation - volatilization.
• the passage of air through the screen is important for an effective sublimation, because the required energy primarily is taken from the air flow.
• FIG. 5 there is shown another type of screen having the same function. In this case the screen is located freely and the poles 23 form conduits for the heat-carrying fluid 20.
• the screens are interconnected in parallel for the lowest possible pressure drop.
• FIG. 6 there is shown a detail of the embodiment according to FIG.
• the heat-carrying fluid circulated through the wind screen can comprise another fluid than water with anti-freezing agent.
• this fluid can comprise freon gas and so-called direct evaporation may be applied.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Paper (AREA)
• Other Air-Conditioning Systems (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26658686

Family Applications (1)

Country Status (3)

Citations (5)

• 1984
  • 1984-04-03 SE SE8401833A patent/SE8401833L/sv not_active Application Discontinuation
• 1985
  • 1985-10-03 WO PCT/SE1985/000382 patent/WO1987002121A1/en unknown
  • 1985-10-03 EP EP85905440A patent/EP0239573A1/en active Pending

Patent Citations (5)

Non-Patent Citations (1)

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