GB2176590A

GB2176590A - A method for producing a climatic effect in double-walled buildings and a building for putting the method into operation

Info

Publication number: GB2176590A
Application number: GB08611319A
Authority: GB
Inventors: Claus-Dieter Herbert; Jurgen Nitzsche; Holger Reum; Manfred Wichtrei
Original assignee: Akademie der Landwirtschaftswissenchaften der DDR
Current assignee: Akademie der Landwirtschaftswissenchaften der DDR
Priority date: 1985-05-10
Filing date: 1986-05-09
Publication date: 1986-12-31
Also published as: DD250847A3; DK191486A; GB8611319D0; FR2581738A1; JPS6226424A; DK191486D0; GB2176590B; FR2581738B1; DE3613050A1

Abstract

A method and building for producing a climatic effect, the building having an internal wall (2) and an external wall (3) between which a gaseous medium is fed as a result of which layers of condensation form on the inner and outer wall surfaces, the gaseous medium being fed through a guiding devices (3) in said space having outlets (8) along their length and one or more additional openings (5) in the inner or outer walls (1,2). <IMAGE>

Description

SPECIFICATION A method for producing a climatic effect in double-walled buildings and a building for putting the method into operation The invention relates to a method for producing a climatic effect in the interior of buildings, preferably double walled greenhouses, using an untreated heating medium such as waste water from mining shafts or the exhaust air from a nearby building and a building for the implementation of the method.

Greenhouses covered with foil are well known in agriculture. These greenhouses are heated by the provision of energy from an external source, that is to say by means of heat generators or other external sources of heat, if the outside temperature and lack of sunlight make this necessary. The use of greenhouses covered with foil heated in this way makes it possible to plant earlier, but they are very costly as they require a high capital investment and operating costs are also high.

A well known solution for improving the insulation effect of double-walled buildings such as greenhouses covered with foil is to circulate water whose temperature has been raised in the space between the double walls. To ensure that the surface over which the water passes is as large as possible and that the heat is used to the fullest possible extent, guide channels or guide elements are normally fitted.

This type of heating has also been used in glass greenhouses but it does however have fundamental disadvantages because it requires the use of guide elements which make the use of this method extremely difficult in practice.

A further decisive disadvantage is that the circulating water does not allow adequate exploitation of the heat.

It is also known from German Patent Specification No. OS 821 959 to wet the wall of a building with water which is pumped out of the ground, maintaining its outlet temperature, which is basically the same as the temperature of the ground, this water being applied at atmospheric pressure by means of spray nozzles to the inside wall of, for example, a double-walled foil tent. This means that the water wets only the inside pieces of foil. The sprayed water then runs down to the foot of the wall and is collected at the bottom of the space between the double coverings and is taken back into the ground. It is possible to adjust the water temperature depending on the external temperature but this requires that the water stay for a fairly long time in the ground or the use of additional energy Sources for raising the temperature of the water.To implement the method, a device is also needed to take the water to the spray heads fitted in the ridge of the building.

After running down over the inside foil wall, the water is collected and taken by means of pipes to a water reservoir underground and, following a dwell time and heating period, it is pumped via a closed circuit to the spray heads.

This known method and building suffer from the following disadvantages. Firstly, it is impossible to install the required complicated circuit for raising the temperature of the water in the ground for the relatively short-lived buildings. Secondly the expenditure on equipment to implement this method is relatively high.

Further methods are known which are based on the direct use of a gaseous medium using coventional ventilation and air conditioning technology in the inside space. In this case, it is necessary to place high requirements on purity or on plant compatibility because media which carry with them substances such as living organisms for example in greenhouses, could cause harm to plant growth and therefore cannot be used.

Further devices are known which directly heat the interior of greenhouses but these are generally devices for heating air, the design of which is extremely expensive and in respect of which it is necessary to place a high requirement on the energy transfer as well as on the purity of the heat carrier.

With this method, the air is conducted through the inside space. The dwell time of the air in the inside space is very brief. A very high rate of air change per time unit of up to 30 changes/hour is necessary.

So far methods intended to use exhaust air have not been used since either the equipment and technological requirements as regards purity are very high or the heat loss is so high that additional heat is necessary so on the whole the implementation of the method is rather uneconomic.

It is an object of the invention to create a method for producing a climatic effect in the inside space of buildings,preferably a doublewalled greenhouse, using an untreated heating medium such as waste water from mining shafts or the exhaust air from stalls and stables. It is a further object of the invention to provide a building to implement the method, by means of which it is possible to use existing heating media, not preheated, and therefore give the building an extremely high functional value taking into account its air conditioning.With the method and building of the invention, it is possible to use the exhaust air from stalis and stables or the waste water from mining shafts which until now have been unsuitable for heating the inside space of buildings, whereby the heat energy, without any technical pretreatment of the gaseous, heat-conducting medium unsuitable for the inside space of the building, can act thermally on these and at the same time possibilities of using the inherent heat and thermal insulation are created by the heat-conducting medium.

The invention overcomes or substantially reduces these problems in that a gaseous medium is taken between the outside and inside walls of a building filling the space evenly from one end of the building to the other longitudinally and transversally to its axes, one or several condensate filtering layers being formed between the surfaces of the double wall, whereby the gaseous medium is enriched with components of fluid, gaseous and/or solid type, flowing over the inside space of the building and is taken out of the inside space at a specific point. In a preferred embodiment, after flowing through the double walls, the medium is taken away to atmosphere. In the event that return air is used, that is to say the air which is extracted from the inside space of the building, this is fed back into the inside space of the building after flowing through the double walls.It is a feature of the invention that the medium from the inside space is fed between the double walls and condenses on these, whereby the condensate adheres in the solid or fluid state and, as a result of these layers of condensation, one or several layers of insulation are formed.

Preferably, the fluid components of the medium are held in a solid or fluid state on the inner surfaces of the double-walled building as a precipitation. This precipitation or deposit, which is in the form of condensed water or, at very low external temperatures, a layer of ice on the inner surface of the double wall, serves at the same time to increase the insulation by reducing heat losses from the interior or in the event that the building is being cooled, the prevention of the penetration of heat into the building.

The building of the invention is designed so that the condensate of the medium can be taken away, if it is not to be used for any further operational function. It is however possible that the condensate can be returned into the thermal circuit, if it is of significance for the regulation of the heat. This is in fact the case when, for example, using the method in a greenhouse, water which has been extensively purified by condensation, can be used in the technical plant production process to have a physiological effect on the plants in the interior space of the building. In accordance with a preferred embodiment of the invention, the medium is introduced at the foot of the two longitudinal sides between the external and internal walls and can exit in the ridge space of the building.

In another embodiment of the invention, it is advantageous to introduce the medium at the foot of one of the longitudinal sides and conduct it between the double walls so that it reaches the foot of the opposite side to be extracted. The medium can however be introduced via the base between the double walls and create possibilities in the ridge space of again removing the medium from the double wall after it has given off its heat energy.

With this embodiment, the regulating of this heat, that is to say the temperature in the inside space is effected by the quantity of medium.

It is an advantage for the temperature regulating to be backed up by the insertion of low-power or high-power or fluid or gaseous energy carriers, the optimum situation being where termperature regulation is effected by control of the temperature of the medium.

The preferred building of the invention is designed in known manner to include two walls which enclose a hollow space between them. Air guiding devices are fitted in this hollow space which have outlet openings, which enable an even distribution of the medium over the whole extension of the air guiding devices, whereby in the area of the ridge of the building, one or several openings are arranged in the double walls. In one embodiment of the invention, openings are arranged in the wall of the building for the introduction of return air, in order to guarantee an internal closed air circulation circuit, if an infeed of heating media from outside is unnecessary. In accordance with one embodiment of the invention, it is an advantage for the air guiding devices to be fitted in the area of the foot of the walls.Preferably, the air guiding devices are formed at the foot of the inside wall and extend up a third of the way up the inside wall. If the greenhouses are designed either completely or partially with vertical side walls, which also have an internal and external wall, the air guiding devices can be fitted at the foot of the external wall, the flow of the medium being directed from the foot of the wall upwards, inlet openings being arranged in the internal wall. In one embodiment of the invention, the outlet openings for the air guiding devices are provided at the top point where the air guiding devices are attached to the inside wall. It is an advantage of the invention if, observing what has already been described, a heating medium is used for the building which can be used, without preparation in its original form with all the types of contamination with which it is affected. The use of such large temperature transfer surfaces which are usual with greenhouses also allows the use of low-power heating media. A fundamental advantage of the method is to be seen in the fact that an overlapping insulation effect is retained on reaching the condensation point of the heating medium. At this time, several condensation filtering layers in the form of thin films form on the double wall of the bulding or greenhouse and thus increase the intended thermal effect. This effect largely minimizes any undesired energy exchange with the surrounding atmosphere.

It should be stressed that the method and building used to implement the method guar antee high operational safety and reliability with extremely low investment costs. It is therefore possible by means of the building of this invention to use exhaust air to heat the building, which when conveyed by the air guiding devices gives off its heat inside the double walls and leaves the building again through the openings in the ridge space.

The use of the enthalpy of the exhaust air requires for the technical operation of the heating a minimum proportion of energy for the media movement but not energy for its heating. It is now possible to use the method to advantage by using the return air for the building itself. The air is then conditioned without the contribution of energy and preferably introduced from the inside space of the greenhouse with increased acceleration via guiding devices provided with openings at the foot of the longitudinal sides of the building into the double walls and passes via the openings in the ridge space of the internal wall of the building back into its interior. The particular insulation effect already explained is achieved in that during operation, on reaching the condensation point of the heating medium, insulating condensation layers form on the coverings.

A preferred embodiment of the invention will now be described by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a cross-section through a double-walled greenhouse.

Figure la is a cross-section through a modified greenhouse.

Figure 2 is a plan view of the greenhouse of Figure 1.

Figure 2a is a plan view of the greenhouse of Figure la and, Figure 3 is a partial axonometric cross-section of the greenhouse of Figure 1.

For the purposes of explanation, the invention will be described in relation to a greenhouse and particularly an aerothermic greenhouse which is a greenhouse covered with foil in known manner, the inside and outside walls being arranged concentrically with respect to each other and enclosing a hollow space between them. At the foot of wall 2, facing space 9, there is an air guiding device 3, which may extend up to a third of the height of wall 2. It is however also possible to provide the air guiding device 3 at the foot of the wall without it extending upwardly. Outlet openings 8 are provided where the guiding device 3 is attached to wall 2 (see Figures 2 and 2a) said openings extending at regular intervals over the whole length of the air guiding devices 3.

In the embodiment of Figure 1, an opening 5 is arranged in the apex or ridge of the outer wall 1. However, if the greenhouse is intended to operate on a recycled air principal, then with the same arrangement of air guiding devices 3 as well as outlet openings 8, an opening 5 is provided in the ridge or apex of inner wall 2 of the greenhouse in order to return the air to the interior thereof. The greenhouses of Figures 1 and 1a therefore differ in their technological operation mainly due to the arrangement of the opening 5 in the relevant ridge part of the greenhouse.

Figure 2 shows the possibility of using exhaust air for heating, in that the air guiding device 3 is connected to a feed pipe 4. Figure 2a shows the possibility of designing the inside air circuit in the greenhouse as a completely closed circuit, since there is no provision for the admission of outside air. In this case the air in the inside space is fed by gable wall 6 to feed pipe 4.

In operation, the heating medium is fed via feed pipe 4 into the air guiding device 3 and into the foil tent. The medium flows into space 9 between the inner and outer walls 1,2 via the corresponding outlet openings 8 and then leaves this space, after giving off its heat energy, via the corresponding openings 5 in the ridge area. An air distribution pipe 4 is fitted in gable 10 with walls 6,7. A test carried out with a foil tent designed in accordance with the invention showed that the inside space was kept free of frost with outside temperatures of up to-200C. The aerothermic greenhouse was on this occasion connected to the forced ventilation system of an adjacent storage building. This caused no additional expenditure of energy for the air conditioning of the greenhouse.The aerothermic greenhouse is designed so that, at the end of the cold weather period when heating is no longer needed, the external or inner covering can be moved along its longitudinal centreline to provide two separate greenhouses for use in the temperate period. The operating systems are therefore kept separate from each other.

If the aerothermic greenhouse is to operate on the recycled air principal, then air is extracted from the interior of the greenhouse, accelerated and then fed via the air guiding devices 3 into intermediate space 9. After flowing evenly through the space 9 between the inner and outer walls 1,2, the air re-enters the interior space of the greenhouse via openings 5 in the ridge area of the inner wall 2.

(See Figure la) Heating or enrichment with moisture in the interior space of the greenhouse can be effected both by well known heating and sprinkling systems as well as by air conditioning devices such as air heaters or spray nozzles, none of which are shown.

Aerothermic greenhouses provide a high degree of insulation which in turn results in a much lower heat energy consuption rate per unit of surface area.

The insulation effect is achieved by the deliberate build-up of the following insulation layers considered from the outside inwards.

a) The external envelope (1) b) A layer of condensation or ice on the external envelope (1) c) A layer of air between the envelopes.

d) The external layer of condensation of the inner envelope (2) e) The inner envelope (2) f) An inner layer of condensation of the inner envelope (8) g) The air guiding device (8) Making use of these specific advantages, it is possible without any great expenditure to use the aerothermic method in conventional greenhouses. A similar effect also occurs when only the vertical walls are converted.

As a result of the described insulation effect, a very good uniformity of temperature is achieved in the area of the plants.

It will be seen from the foregoing description with reference to the drawings that the invention provides a method for producing a climatic effect in double-walled buildings and a building for the implementation of the method, with which the heat energy, without any technical pretreatment of the gaseous, heat-conducting medium which is unsuitable for the inside space of the building, can have a thermal effect on this space and at the same time provide possibilities of utilising the inherent heat and providing thermal insulation through the heat-conducting medium. This is achieved using a gaseous medium which is fed between the external and internal wall of the buildings filling the intermediate space evenly from one end of the building to the other forming one or several condensation filtering layers longitudinally and transversally to its centre-lines between the surfaces of the double-wall, whereby the gaseous medium is enriched with components of fluid, gaseous or solid type and after flowing around the inside space of the building is removed from the intermediate space at one or several specific points.

Claims

1. A method for producing a climatic effect inside a building having an internal wall and a spaced external wall such as a double-walled greenhouse comprising the steps of feeding a heated gaseous medium between the external and internal walls of the building to evenly fill said space, forming one or several layers of condensation between the surfaces of the inner and outer walls from one end of the building to the other to enrich the gaseous medium with fluid, gaseous and/or solid type particules, said gaseous medium being removed from said space at one or more exits after it has flowed round the space intermediate the inner and outer walls.

2. A method in accordance with claim 1 wherein the gaseous medium is removed to atmosphere after it has flowed between the inner and outer walls.

3. A method in accordance with claim 1 wherein the gaseous medium is fed to the interior of the building after it has flowed between the inner and outer walls.

4. A method in accordance with claims 1 and 3, wherein the gaseous medium is fed from the space between the double walls and condenses on these in a solid or fluid state.

5. A method in accordance with claim 4 wherein one or several layers of insulation are formed by the layers or condensation.

6. A method in accordance with claim 1 wherein components of the medium in the solid or fluid state are held on the inner sides of the double wall of the building as a precipitation.

7. A method in accordance with claims 1 and 3 wherein the condensation of the medium is taken away.

8. A method in accordance with claim 6 or claim 7 wherein the condensation is conducted back into a further thermal circuit for heat recovery purposes.

9. A method in accordance with claim 7 wherein the condensation is fed back for further processing in the physiological development of the plants in the interior of the building.

10. A method in accordance with claim 1 wherein the gaseous medium is introduced into the space between the inner and outer walls at the base thereof and is removed at the ridge thereof.

11. A method in accordance with claim 1, wherein the gaseous medium is introduced at the base of one longitudinal side wall and is removed at the base of the opposite side wall.

12. A method in accordance with claim 1, wherein the gaseous medium is introduced at the base between the inner and outer walls and leaves at the ridge thereof.

13. A method in accordance with claim 1, wherein the temperature of the interior space of the building is regulated by regulating the quantity of gaseous medium supplied thereto.

14. A method in accordance with claim 12 wherein the temperature is regulated by controlling the temperature of the gaseous medium.

15. A method in accordance with claim 1, wherein temperature regulation is effected by the insertion of low or high-power, fluid or gaseous energy carriers.

16. A double walled building such as a greenhouse having an inner and outer wall formed of foil, means for feeding a gaseous medium into the space between said walls, an air guiding device in said space having outlet openings along its length and one or more additional openings in one or other of the inner or outer walls.

17. A building as claimed in claim 16 wherein the additional openings are arranged in the inner wall for the return feed of air into the interior of the building.

18. A building as claimed in claim 16, or claim 17 wherein the air guiding devices are arranged in the area adjacent the base of the interior and exterior walls.

19. A building as claimed in any of claims 16-18 wherein the air guiding devices extend upwardly by one third of the height of the interior wall.

20. A building as claimed in any one of claims 16-19 wherein, in the case of greenhouses with complete or partial inner and outer walls, the air guiding devices are arranged at the foot of inner wall and the flow of gaseous medium is directed upwardly from the base thereof, inlet openings being provided in the inside wall.

21. A building as claimed in claim 18 wherein the outlet openings of the air guiding devices are the top point where the air guiding device are connected to the interior wall.

22. A method for producing a climatic effect inside a building substantially as herein described with reference to the accompanying drawings.

23. A building substantially as herein described with reference to the accompanying drawings.