NL8600650A - DEVICES FOR INFLUENCING WIND AND TEMPERATURE. - Google Patents

Abstract

Means for keeping down the energy consumption for cooling spaces open at their sides like indoor artificial skating-rinks and outdoor artificial skating-rinks. The means is a wind/heat barrier surrounding the space or the ground, consisting of a system of tubes arranged at a distance from one another through which a refrigerant flows and which acts as a heat exchanger.The barrier at its top preferably contains a device dispersing moist over the tube situated underneath. The tubes are preferably provided with a coating with a high emission coefficient for longwave heat radiation.

Description

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Arrangements for influencing wind and temperature *

The invention relates to provisions for influencing wind and / or temperature in interior or exterior spaces, in particular for use on ice rinks.

Initially, such a facility is a fence that is placed around outside artificial ice rinks with the intention of limiting the cold requirement of the ice rink by the wind shielding effect. The permeability of the gate is 50 ± 10Z to make the wind shield as optimal as possible. A more favorable wind climate for the skaters on the track due to this wind shield is also the result. The gate height 10 can vary from 1 to more than 10 meters.

The gate is also designed as a heat exchanger consisting of horizontal and / or vertical pipes. The pipes can in principle be smooth, but can also be found. The cooling medium flows through these pipes, with which the condensation heat of the cooling installation is removed from the pipes to the ambient air. The coolant in the pipes is water or antifreeze.

A water metering device (gutter or pipe) is arranged above the fence and parallel thereto. The water flowing over the underlying pipes will evaporate, resulting in considerably improved heat transfer by evaporative cooling. When the fence is constructed with vertical pipes, the wetting of the pipe surface by the water metering device will be better than with horizontal pipes in which falling drops can be blown away by the wind. The water dosing device can be designed as a round pipe with holes or as an open gutter, with the water flowing over the edge. For an even distribution over the entire perimeter, this pipe or channel could be segmented. The surplus of run-off water must be collected in a gutter under the fence and can be recycled if desired after filtering. Due to lime-growth on the fence, collected rainwater or softened groundwater can be used if possible.

The heat output of the gate is largely determined by the emission of long-wave heat radiation. For the best possible appearance, the fence should have a high emission coefficient of 35 * Λ Λ ^ t · Λ ö ·; 11 I. I. 1.1.11. Hl II Ί.ΙΙΙ ·· wa I I - ^ -'S '' - 2 - cient. Zinc-coated metal fences have a low emission coefficient. This can be increased by applying a coat of paint to the fence. The paint should then preferably be white, due to sunlight reflection. When the gate is wetted, the emission coefficient is again high due to the presence of water on the pipes. In that case, a paint layer may be dispensed with. Because the application of white paint on a metal fence with a low emission coefficient for heat radiation (for example zinc) can mean the difference between an acceptable gate temperature and a gate temperature that is too high for the cooling system, in case of little wind and a lot of sun, the application becomes of paint or any other medium with the same properties for short and long wave radiation considered as a possible embodiment of the wind-heat fence, which is covered by the patent application.

15 If the cooling installation is not in use at low outside temperatures (below 0 ° C), there is the possibility of cold buffering via freezing of water or in an eutectic medium. This cooling can considerably increase the efficiency of the cooling installation by cooling the hot condensed medium from the condenser. The cold-20 buffer could preferably be integrated with a snow pit or square for the scraper ice from the artificial ice rink.

All draft holes that are located between the slope and the buildings at the main stand or between the buildings themselves or between the buildings and the stand must also be provided with half-through (last 25) windshields, it being understood that the lower meters of the windshield must be closed. The rink is then surrounded by a dense wall consisting of embankment, dense windshields and main stand, or other buildings, respectively. The air below the level of this ramp is cooled by the ice surface and forms a stable cold blanket above the ice. This results in an additional reduction of the convective load. In calm weather and clear weather, this can cause "frost" at air temperature above zero. This phenomenon is known in, for example, dune pans where on clear nights temperature differences between the 35 dune top and the dune bowl of more than 10 ° C can arise. The air that comes into contact with the walls of the dune bowl, which cools down by 85 ft after ή

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* - * o * - 3 - radiation to the atmosphere, cools and collects at the lowest point, where frost can form.

Of the various elements by which the cold requirement of an ice rink 5 is determined, such as: convection load (wind air temperature, air humidity), solar radiation (short-wave) and radiation (long-wave), the radiation is negative on average in the winter season. This means that the outdoor track benefits from the atmosphere as a free cold source. A good covering must be able to reduce the convective sun-10 and rain load without lowering the radiation.

A further provision is a covering net.

For example, the net consists of plastic with a mesh opening of a few mmfs (50 ± 10% air permeable). This cover is hung horizontally above the ice at a height of a few tens of 15 centimeters. The convective load decreases enormously (a factor of 5 to 10) due to this type of cover due to the wind reduction under the net and the cold air blanket under the net, which is created by a stable thermal stratification. The net cover is relatively insensitive to wind load due to its open structure and horizontal low position.

20 Due to its open structure, the net already lets a lot of heat radiation into the atmosphere (* radiation). Even more profit is obtained by the choice of net material that is transparent to heat radiation.

Some plastics such as polyethylene have this property. Additions to obtain UV resistance cause a higher absorption of heat radiation and are therefore in principle undesirable. This invention also encompasses all applications of nets in which they are used for covering (artificial) ice rinks regardless of the choice of material.

The semipermeable net will reflect or absorb a portion of it because of its open structure when exposed to conspicuous sunlight. A white net will heat up less than a black net due to increased sunlight reflection, so that the white net radiates less heat radiation to the runway. A special embodiment of the cover is a polyethylene net 35 with a slight addition of titanium dioxide to the net material.

As a result, the polyethylene just takes on a white color while retaining p - η λ .s z Λ

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The net must be attached to a movable support structure, which can move (semi-) automatically. When the ice rink is open, the net and support structure must be stored in a gutter or tray along the inside or outside of the track. Given the accessibility of the track, the interior is preferred. When using a semi-permeable inner boarding that serves as a permanent windshield, integration with the storage channel or container is possible. The support construction can in principle consist of steel cables which are stretched over the track in the form of triangles with winches.

The fine-meshed net is particularly useful during the ice-making period. Pre-applied, the ice floor can be built up with spray water through the net. During the day when not spraying, it can just stay put. The winches can pull the covering construction over the track by means of "pull-up wires" across the track. The lift wires must be attached to the winches by technical personnel.

In the rain, the fine-meshed net will partially close due to the capillary action, so that the convective load can decrease even further.

By giving the net an angle of inclination relative to the horizontal, it can be ensured that rainwater drains through the meshes to the edge of the track. This further limits the cold requirement and prevents ice build-up.

Rainwater runoff can be improved by using the spruce supports that support the net, and to give different angles of inclination. This gives the whole the appearance of a greenhouse cover. The rainwater can be drained via the lowest tension wires, under which a rain gutter of foil material is attached.

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In connection with the stated with regard to the non-cover of non-covered artificial ice rinks, in which it is not possible to skate on the ice rink during covering, the invention comprises a cover (whether or not removable) that can be used during skating. .

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The roofing of the track can in principle take place with a conventional steel construction as support. If only the ice surface is covered, the covering is preferably constructed in such a way that the supporting profiles are placed only on the outside, so that there are no visual obstacles in the form of uprights on the inside of the track.

The vertical outer side wall of the canopy is semi-permeable. Two special embodiments are: - nets approximately 50% + 10% permeable 10 - wind-warm fence.

A semi-permeable inner boarding has been applied along the inside of the track. Embodiment: plastic / metal nets. Height approximately 1.20 - 1.30 m (no higher) for overview of the track. On the top side of the roof, a semi-permeable screen of 1 to 2 m. Height is arranged along the inside of the track, vertically depending on the wind. This screen can be rolled out to the ground in bad weather.

The roof itself is made of white plastic film, which transmits heat radiation well and reflects sunlight (for example 70% and 60%, respectively). In clear sunny weather this can cause a small or even negative net radiation load on the ice rink.

Together with the low convective load on the ice rink due to the wind-limiting side walls, the cold requirement of the ice rink is minimal. A special embodiment of the roof is a plastic roof 25 with a network structure which has a 50 ± 10% mesh opening and which otherwise has the same properties as the above-mentioned foil. This embodiment has the advantage over a closed foil roof that the wind load is considerably less, so that the entire construction can be made lighter. Another advantage is the low noise load in rain. A drawback is that despite a certain angle of inclination of the net roof, the drainage of rain may not be 100%.

An improved embodiment with regard to rainwater discharge is obtained by alternately tensioning the tension wires supporting the net high and low. This gives the roof the appearance of a greenhouse roof. The rainwater can be drained via the lowest tension wires, under which a rain gutter is attached, Λ - "\ '> Λ i - 6 -

Films that reflect sunlight well (for example 60%) and transmit heat radiation (for example 80%) can be considered as radiation-selective materials. By making the foil thicker or thinner, less or more solar radiation or less or more warm test radiation will be transmitted. This phenomenon has, for example, the plastic material polyethylene in particular when it is designed as low-density polyethylene. The tensile forces exerted on the material during the manufacturing process, including small gaps in the material, which give the material a white color. The stretching gives the molecular chains a certain preferred direction and the foil a high strength in that direction. Laminating several of such layers on top of each other, with the strength directions at right angles to each other, results in a very strong yet thin film, which has the desired properties. This manufacturing cage process is known. The invention includes some special applications of such films, taking advantage of the fact that high sun load is always accompanied by a high heat radiation to the atmosphere.

Glasshouses in tropical areas have the drawback that the "greenhouse effect" means that high costs must be incurred for cooling the greenhouse air. This often takes place in tropical areas by passing groundwater over a distribution package, while very dry ambient air is blown through the package in a cross flow. The evaporating water extracts heat from the hot air, which is thus blown into the greenhouse cooled and humidified (adiabatic cooling). Because cooling is required continuously, the greenhouse is continuously extracted with the help of fans. All this is accompanied by enormous water consumption, energy consumption, while the cleaning and replacement costs of the calcified distribution packages are also very considerable. The object of the invention is to remove a considerable part of the cooling load by using radiation-selective plastic films.

The glass cover of the greenhouse is partly (possibly side walls) or entirely (roof) replaced by the radiation-selective foil, which has a thickness such that the net radiation received is small or zero.

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If there is a surplus of natural light in the greenhouse, the side walls and front and rear facades can also be equipped with radiation-selective plastic foil instead of glass. In the case of a version with 100% foil, a possible construction form is the foil greenhouse, wherein the supporting structure can be constructed very lightly in the form of, for instance, half arcs on which the foil rests.

With sufficient light in the greenhouse, the vertical walls of the greenhouse can be covered with aluminum foil. This results in the following favorable effects: * 0 - Heat radiation from the warmer environment of the greenhouse is blocked.

- At high foil temperatures, the heat radiation emitted by the foil itself will be low.

- Additional radiation cooling takes place between the greenhouse content and the atmosphere via the vertical greenhouse walls.

In warm areas, straw, corrugated iron and the like is often used as roofing of residential houses. The disadvantage of these materials is that the sunlight is no longer transmitted, but is partially absorbed. The hot roof then emits heat radiation, which contributes to the heat load of the house. The shortage of light through the roof must be compensated for by windows in vertical walls, which in turn can give additional heat radiation load. The use of radiation-selective foil as a roof covering can mean sufficient light with not too high internal temperatures. The housing contents can now "cool" by the emitter of heat radiation through the foil roof.

The radiation-selective foil material can also be used as a tent material in hot areas. This could include operating tents for remote areas where electricity and cooling are lacking. This material may also be suitable for permanent habitation of tents. For the nighttime situation in connection with possible excessive cooling, a combination with a radiation-impermeable screen, for example aluminum foil, may be desirable.

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The radiation-selective film may also lend itself to the production of fresh water from brackish water (for example, sea water). Production then only takes place during the day. The salt water evaporates with the help of solar collectors by means of the absorbed solar radiation. The thus saturated air is extracted between a horizontally arranged radiation-selective foil and a solid surface. The water vapor in the air will cool and condense via contact with the relatively cold solid surface. The exiting air which is still saturated with water vapor at lower temperatures can be reheated and humidified via the solar collectors via recirculation.

The invention also includes the use of semi-permeable nets for outdoor swimming pools and cooling water ponds. The purpose of the cover for outdoor pools is to save energy, for cooling water ponds to prevent evaporation mist in favorable weather conditions. The idea was derived from research into energy savings in artificial ice rinks. See TNO report 85-014144, among others. The biggest advantages in comparison to other carbon black covers are: 20 - wind resistance - light weight - cheap

The net primarily serves to reduce the wind speed above the water surface. With a net with a diameter of 50 ± 10%, 25 <Your reduction is a factor of 5 to 10. The net is suspended horizontally and a few tens of cm above the water surface. The effect of this is: - The water surface is at rest, so that the evaporation surface is minimal.

30 _ The convective heat transfer coefficient is minimal, as a result of which both convective heat transfer and evaporation transfer decrease equally.

35 8800650 - 9 - - The temperature of the air between the net and the water surface will rise. As a result, both forms of heat transfer decrease. In the heat transfer by evaporation, both the difference in absolute moisture content of the air between the water surface and the surface above it decreases, as does the difference in entalpia.

- If the mesh opening is sufficiently small (in the order of mms), it acts as a drip catcher. The rising vapor partially condenses on the net and falls back into the water. For cooling water ponds, this means an additional decrease in fog formation. An additional reduction in heat transfer results from the capillary action of the net with a fine mesh structure. As a result, the permeability of the network decreases, the more the humidity of the environment increases. In cooling water ponds where there is also spirake, odors from co-evaporating substances from the pond, some of these substances will be returned with the falling condensed drops.

- Due to the fog formation under the net at a lower temperature than the water surface and through the net, the cooling by heat radiation will decrease. In principle, the heat radiation from the sun is also reduced by the net, which is positive for cooling water ponds but negative for swimming pools. In cooling water ponds, moreover, at a given wind speed, proportionally more ambient air is mixed with new moist air, so that the mist cloud is thinned more strongly. The fog cloud is therefore expected to be smaller in size, which is of great importance in case of fog nuisance.

- In open-air swimming pools, the optimal degree of transmission of the net is probably slightly less than 50%, for example 60 to 70% in connection with more sunlight entering. The choice of the net material should preferably not be black in swimming pools, but transparent for sunlight and impermeable to heat radiation (for instance PVC). Such a net, which is stretched over the bath in the preseason, is expected to be able to bring the water temperature to the desired level only with natural radiation.

A net with a diameter of 40 ± 10% 35 and a mesh size of one or a few mm is suspended above the bath.

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In a special embodiment, the passage is reduced for the purpose of the night cover by: - Moving the net on one side of the bath parallel to it.

- A second net with, for example, 20% passage can be arranged over the bath above the first net. The resulting passage is then approximately 10% while the wind sensitivity is still small due to the small pressure differences. The second net can rest on the first net if desired. During the day with sufficient sun (for example irradiation more than 300 W / m2, not too much wind and too low temperatures), the cover can be removed in the 10 warm-up period.

In cooling water ponds, fog nuisance is drastically reduced by using semi-permeable nets (50 ± 10%), which are UV-resistant and are suspended at approximately 20 cm from the water surface. Due to snow loads, the space between the water and the net should not be chosen too high. The net only hangs above that part of the pond that causes fog nuisance. When the net is used, the cooling over the hottest part of the pond will decrease, so that a larger area than the original roist area must be covered. Cascade cooling water ponds are thought to account for approximately 25% of the total surface.

Based on measured water temperatures and weather conditions, the decision to remove the cover can be made automatically using a micro-computer. The latter periodically makes calculations on the measured values of the said quantities and determines whether or not the cover should be removed or the second cover applied.

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Claims (24)

1. Device for limiting the use of energy required for cooling at least on the sides open spaces »such as halls and areas exposed to the outside, such as artificial ice rinks, 5 characterized in that it is a fence, or with one another fence parts that can be completely assembled, with which the space or terrain is surrounded, consisting of, at least comprising an assembly of spaced apart pipes, which functions as heat exchanger in cooperation with a cooling medium to be guided there. 2. Device according to claim 1, characterized in that the gate is provided at its top with a device extending over its length for dispensing moisture. 3. Device according to claim 2, 15, characterized in that the device is a tube, with holes in its wall. 4. Device according to claim 2, characterized in that the device is a gutter open at its top. Device according to any one of the preceding claims, characterized in that the gate is provided with a coating with a high emission coefficient for long-wave heat radiation. 6. Device according to claim 5, characterized in that the coating is white. Device according to one or more of the preceding claims, characterized in that the pipes in use form part of a circuit that contains a cold storage facility or that provides cooling for another room, floor or the like, 8. Open space or terrain on the sides, characterized in that it has a provision according to one or more of the preceding claims, respectively. Method for keeping the temperature of an outdoor surface of a liquid or solid medium as constant as possible, characterized in that the surface is spanned at some distance above it with a fine-mesh net with mesh openings of a few 8600650 - o «u 'rkw - 12 - millimeters and with an air permeable surface of approx. 50%. 10. Method as claimed in claim 9, with b, ti! I.ÊÜGltC! L, that the net is applied in such a way that it encloses one or more angles of inclination with the horizontal plane over the entire surface, so that striking water along a (de) slope (s) descends downwards. 11. Method according to claim 9 or 10, for counteracting heat loss of the water of outdoor swimming pools, with the <6ü! 5Ëd <that the net is stretched a few tens of centimeters above the water surface. Method according to claim 9 or 10 for reducing cold loss of the ice floor of an outdoor artificial ice rink, characterized in that the net is stretched a few centimeters above the ice floor. * Device for carrying out the method according to claims 9-13, characterized in that it comprises a fine-meshed net and a support structure for the net to stretch it over the relevant surface. 14. Device as claimed in claim 13, characterized in that the support construction is movable in such a way that the net can thereby be tensioned over the surface or removed from it again. Device according to claim 13 or 14, 25, characterized in that the support construction consists of steel cables which can be tensioned above the surface. 16. Device as claimed in claim 15, characterized in that in the tensioned condition the tension cables alternately give different angles of inclination with the horizontal plane to the net and that a drainage channel is attached at the bottom of the lowest tension cables. 17. Outdoor swimming pool, provided with a net and provided with a device according to one of the claims 13 - 16. IS. Outdoor artificial ice rink, provided with a net and provided with a device according to any one of claims 13 - 16. 19. Method for laying or updating an ice floor for an outdoor artificial ice rink provided with a net, with water being sprayed on the net, which is passed through the net 860 0 650 • ~ ar-. - 13 - go out and underneath »forms ice on the cooled surface. 20. Method according to claim 19, characterized in that use is made of a device according to any one of claims 13 - 16. 21. Device for outdoor artificial ice rinks, whether or not in combination with one or more of the features of the preceding claims, comprising: - a removable cover over the track »made of a material which has a high transmittance to heat radiation and a high reflection. for solar radiation; - from the roof extending downwards on both sides »removable» for approximately 50% breathable walls, 22. Device according to claim 21, wherein the material of the covering is a white plastic foil, preferably low-density polyethylene. 23. Device according to claim 21, wherein the material of the covering is a plastic with a net structure with approximately 50% mesh openings. 24. Device according to any one of claims 21 - 23, wherein the roof is inclined with respect to the horizontal plane. 25. Device according to any one of claims 21 - 24, wherein the side walls can be rolled up. 26. Outdoor artificial ice rink, equipped with a provision according to one of the claims 21 - 25. 8600650