SE513178C2 - Chemical Heat Pump with solid substance - Google Patents

Abstract

In a chemical heat pump a substance is used which in an efficient way interacts with a volatile liquid such as water. The substance is selected considering among other things the magnitude of its DELTAT and its energy content so that the heat pump becomes suited for converting low grade heat energy such as solar energy to cooling for airconditioning and also for a simultaneous production of heat for example for use as hot tap water in houses. The heat pump can also be used in a refrigerating box. Suitable substances comprise barium hydroxide, lithium hydroxide, strontium bromide and cobalt chloride. The substance is applied as a layer (23) on the surface of a heat conducting wall (22) by applying a slurry-like mixture of the substance with the liquid when being vibrated to the wall between heat conducting flanges 25). The mixture is dried under a vacuum and is heated and is simultaneously compressed by applying an exterior pressing force. This gives a solid, well adhering layer of a substance having a high porosity which can resist a large number of cycles without any degradation of the internal structure of the layer and of its adherence to the heat conducting wall and the flanges.

Description

15 20 25 30 35 40 Isis 178 i ~ 'VÄ 51 ”. t 2 with a heat accumulator in the form of a cylindrical chamber and a space for the evaporator / condenser located below it separated by a partition. In one embodiment, the accumulator part has a surface-enlarging and heat-conducting structure designed as a rectangular winding of metal wire wound as a screw. There is a heat exchanger in the accumulator part and the evaporator / condenser. On the inside of the evaporator / condenser part there are support elements covered with capillary-sucking fabric. In the accumulator part in the spaces between the parts of the screw-joined end, a breast material is applied, in the preferred case a mixture of cellulose and graphite, which is then allowed to absorb sodium sulphide. The graphite is included in the mixture to improve the friendly conductivity properties. Plastic sheets can be previously arranged in the accumulator part, which are removed after introduction of the mixture, so that cavities for the expansion of the mixture are formed. The sodium sulfide is generally applied at elevated temperature in its most hydrated form such as Na 2 S-9H 2 O, i.e. in molten form, and is absorbed by the mixture and sodium sulfide crystals are then formed by cooling. These crystals bind at the end of the accumulator through the fibrous material.

Thus, when using sodium sulfide in an accumulator, there is firstly a problem associated with the adhesion of the sodium sulfide to the heat exchanging surfaces, so that without a fiber leaching as above, after a number of cycles small gaps can occur between the layer of sodium sulfide and the surface. to and from which heat is transferred resp. removed from resp. to the sodium sulfide. In addition, there is a second problem associated with the formation of other gases in the long term, so-called residual gas, see below.

DISCLOSURE OF THE INVENTION It is an object of the invention to provide a chemical heat pump which can be used for operation by means of solar energy.

It is a further object of the invention to provide a chemical heat pump which is capable of performing a large number of cycles with charging and discharging without degrading performance.

It is a further object of the invention to provide heat exchanger elements for a chemical heat pump which have efficient transfer of heat between heat conducting parts of the element and an active substance and which allow the active substance to be applied to heat conducting parts in such a way that the substance effectively can interact with a gas phase of a volatile liquid.

For a chemical heat pump to work in practice, the active substance, which performs the actual process in the heat pump, ie absorption and release of a sorbate, must meet at least the following criteria: 1. The substance must have a suitable AT, where AT is the temperature difference, which at pressure equilibrium prevails between substance and the volatile, dipolar liquid in condenser / evaporator.

A suitable AT for systems with water / water vapor is in the range 20 - 40 ° C, see the discussion below. 2. The substance should preferably react with the gas, ie the vapor phase of the wettable liquid, at one and the same phase transition with constant AT or at least at phase transitions with near varying 10 15 20 25 30 35 40 513178 '' f 'l "|' f | . '|' other horizontal AT. 3. The substance must at all times during the process remain solid, ie have a suitable melting point in relation to the process temperatures. '4. The substance must not sublimate. 5. The substance must be chemically stable and clear long-term operation 6. The substance must not emit gaseous by-products other than the gaseous liquid in gaseous form 7. The substance must be mechanically stable and not change structure over time or show significant changes in its external shape, when it absorbs and emits The substance must have a high reactivity with the gas phase of the fl liquid liquid and maintain the high reactivity over time for as many cycles as possible 9. The substance must have a high energy content calculated as evaporation energy of k evaporator / evaporator side per volume of substance. 10. The substance must be able to be applied to heat exchanger surfaces and not have a tendency to detach from them, ie be fixedly applied to the surfaces, which can be achieved if the substance can be slurried in water to obtain a slurry, see the discussion below. 11. The substance should not be corrosive, flammable or otherwise pose a problem to, for example, the environment or an operator. 12. The substance must not be too expensive to obtain or manufacture.

How the quantity AT mentioned under point 1 is defined is shown in the diagram in Fig. 6. Here the vapor pressure is shown as a function of the temperature for pure water and for a typical salt MeX with crystal water. As above, the temperature difference AT indicates the difference between the temperature of a quantity of salt and the temperature of a quantity of water, when an adiabatic process involving the quantity of salt occupying water vapor proceeds. As can be seen from the diagram, AT is fairly constant at pressures around the atmospheric pressure.

Criterion 1 is especially crucial when designing a chemical heat pump intended for solar-powered air conditioning. During the charging phase, occurring during the day, the outdoor temperature can be very high. As the condenser / evaporator will preferably be cooled with a liquid fl fate from an air heat exchanger connected to the air conditioning system, the current outdoor temperature will limit the condensing temperature. Thus, at an imaginary charge temperature of the substance oxidized to about 90 ° C, the possible AT value of the substance is also limited.

Taking into account that approx. 10 ° C must be reserved as a power-driving temperature difference on both the substance side and on the condenser / evaporator side, at an outdoor temperature of 40 ° C only 30 ° C remains to the substance AT. The selected substances should therefore be limited to only substances with AT between 20 ° C and 40 ° C. Criterion 1 must also be satisfied in the current circumstances, which exist when the system is discharged. In the case of a discharge, which for the application of solar-powered air conditioning is preferably intended to take place at night, the minimum cooling temperature generated by the system is limited by the temperature of the substance during discharge, which is also determined by the liquid flow from the air conditioning system. 4 air heat exchangers. For example, if this temperature is 30 ° C and 5 ° C must be reserved on both the substance side and the condenser / evaporator side as the power driving temperature difference (the discharge effect is lower due to a longer time cycle) and the cooling water for the pipe coolers must be 10 ° C, the substance must have an AT of 30 ° C. However, some substances such as LiOH and Ba (OH) 2 have the great advantage that their AT decreases with increasing temperature and thus facilitates charging at high temperature of the condenser. Criterion 3 must also be carefully considered. Many substances have a sufficiently high melting point at the utilized phase transition or the utilized phase transitions, but have a significantly lower melting point at a subsequent phase transition. If the vapor pressure of the substance in saturated solution is low enough to meet the transition to this phase somewhere in the system, the substance will partially transition into liquid phase. This is especially risky near heat exchanger artery at high power consumption, because if melting occurs, the substance can detach from the surfaces.

Criterion 4 also sorts out certain possible substances. Thus, oxalic acid (COH) O-2H2 O has an AT of 30 ° C and a relatively high energy content but it sublimates within the temperature range within which a solar powered heat pump is operated. Sublimation means that the substance's own vapor pressure is so low that the substance evaporates without first melting. When used in a chemical heat pump at the current temperatures and pressures, this acid is transferred as a finely divided powder to a condenser. As a result, there will eventually be no substance left in the reactor. Boric acid BOOH, which is an otherwise good substance suitable for heat storage but which has too high AT to be able to be used for the air conditioning application intended here, also sublimates during charging.

In criterion 9, the term energy content means the evaporation energy required for the gasification, when a unit of volume of the substance absorbs the gas phase of the volatile liquid. A high energy content here is at least 0.15 kWh / l, preferably at least 0.2 kWh / l and preferably at least 0.3 kWh / l.

A number of substances, which correspond to the set criteria, have been developed and tested under realistic conditions. All substances are primarily intended for the conversion of thermal energy to cooling, but heat can in some cases be obtained at the same time as cooling is generated.

The substances are suitable for solar-powered air conditioning systems as well as for refrigerators and cooler bags, which can be charged by heating with electrical resistance elements or other optional energy source.

All substances are intended to be used with water as the working medium. Water has a high steam-forming energy, is cheap and harmless and provides a suitable temperature on the cooling side in the intended applications.

Primarily selected substances include 1. CoCl2 (Cobalt Chloride) in the phase transition 1 - 2 H 2 O with AT = 42 ° C and the phase transition 2 - 6 H 2 O with AT = 20 ° C. Ba (OH) 2 (Barium hydroxide) in the phase transition 1.5 - 6.5 H 2 O with AT = 20 ° C. LiOH (Lithium hydroxide) in the phase transition 0 - 0.65 H 2 O and AT = 25 ° C. 4. SrBr 2 (Strontium bromide) in the phase transition 1 - 6 H 2 O and AT = 35 ° C. 10 15 20 25 30 35 51-3 1'i7 “8 '- || q | All of these substances thrive extremely well as an active chemical in a chemical heat pump for a cooling end needle. SrBr2 has a high enough AT to also be able to produce heat at the same time as cooling is produced, at a temperature level that, for example, allows the production of domestic hot water. Substances are very reactive with water vapor and show no difficulties in either discharging or charging. No detectable reaction inhibitions occur over time as a result of gaseous cleavage products formed. No structural changes have been noted between a large number of cycles. The substances have a high energy content calculated as cooling energy per volume of substance. The energy content for all these substances except LiOH is about 0.2 kWh / l for dry packing and about 0.3 kWh / l for drying with the slurry method, see below. Lithium hydroxide has an energy content of about 0.15 kWh / l for dry packing and about 0.17 kWh / l for slurry packing.

The cooling effect is determined by the design of the system. The transfer of energy between the substance and the heat exchanger is in a solid state system significantly reduced compared to the case of a substance in the liquid form. The effect is primarily determined by the thickness of the substance layer on the heat exchanger surfaces and by the gas availability to these substance surfaces. However, it is possible to significantly increase the effect if thin and preferably extremely thin layers are used, such as with a thickness of at most about 10 mm. As a result, significantly greater flexibility can be achieved in the adaptation of substance and technical construction to practically useful applications.

In a reactor for a chemical heat pump, in which the function is optimized for fast charging, long discharge times and high power turnover, both heat conduction and diffusion in the solid should take place in the same directional direction within the substance. By reactor is meant here the vessel in which the active substance is placed and in which the reaction of the substance with the gas phase of the volatile liquid takes place. An improvement of the friend's conduction conduit by integrating a properly directed grid, mesh, wire or pleated strip made of metal or other suitable material should thus be supported by other measures which improve the diffusion in the microchannels of the substance.

In the reactor there is a heat exchanger unit, which transfers heat between the active substance and an external medium. The chemical substance can be integrated with the heat exchanger unit to form a compact unit, in which a heat transport-improving structure, also called heat-bearing arrangement, attached to heat-exchanging surfaces in the heat exchanger unit mechanically stabilizes the substance to form a combined heat exchanger / maximum heat exchanger between substance and the surface of the heat exchanger is obtained, compare the discussion above of US U.S. Patent 5,440,899 to De Beijer et al. To obtain such a combined unit, the chemical substance is slurried in a suitable amount of water, which constitutes a certain excess in addition to the substance's most hydrated state of working molar contents. Prior to that, the chemical substance has obtained a suitable grain size distribution by sieving, and the substance will then form a desired slurry-like mixture when suspended in water. During stirring or preferably vibration, this mixture is applied to heat-exchanging surfaces provided with heat-bearing reinforcement in the heat exchanger unit.

During a gradual decrease of the atmospheric pressure around the area including that of the host; When the slurry-like substance is applied to the 6 interchangeable surfaces while a gradual temperature rise of this area is achieved, the substance is dried to assume conditions approaching its working molar content, i.e. water is caused to leave the unit. This vacuum drying process preferably takes place at the same time as a gradually increasing force compresses this area and thus the substance into a homogeneous dry layer. Thereby an improvement of the diffusion in the microchannels of the substance is achieved. The process of applying the substance under preferably vibration and of carrying out final formulation by simultaneous gradual drying and also pressing of the substance maximizes the packing density and thereby the energy density of the substance applied to the heat exchanger structure.

In a preferred geometric design of the heat exchanger unit and its surfaces to retain the substance, which design is here referred to as the planar self-supporting reactor, this final shaping can take place in place in the reactor itself during the final stage of manufacture. The pressing moment of the final formation is generated from the action of the atmospheric pressure on an outer enclosure of the substance, so that the walls of the outer enclosure through the self-supporting structure press against all substance layers in the reactor.

In circular or cylindrical reactors with radially set heat exchange surfaces, which are thus in the axial plane, it can be difficult to use substance layers which are sufficiently thin over their entire extent, even if such a geometry has obvious structural advantages. An alternative would be to have the heat exchange surface substantially in the radial plane, i.e. in planes perpendicular to the axis of the cylindrical mold, as shown by the helical surfaces in the above-discussed U.S. Pat. 5,440,899 to De Beijer et al., DESCRIPTION OF THE DRAWINGS The invention will now be described by means of non-limiting exemplary embodiments in connection with the accompanying drawings, in which Fig. 1 is a schematic view of a chemical heat pump, Fig. 2a is a cross-section through an integrated heat exchanger-substance unit, Fig. 2b is a perspective view of a self-supporting accumulator with fl your heat exchanger-1 substance units, Fig. 3a is a schematic cross-section through a chemical heat pump with accumulator and evaporator / condenser in the same circular closure / housing, Fig. 3b is a schematic cross-section through a circular substance unit, Fig. 3c is a perspective view of a part of a circular substance unit, Fig. 3d shows a detail of a circular substance unit, Fig. 4 is a schematic view of a chemical heat pump in an air conditioning system, Figs. Fig. 5 is a cross-section through a chemical heat pump used as a cooling element in a cooling box, and Fig. 6 is a diagram showing the vapor pressure of water and a metal salt as a function of temperature. peraturen.

PREFERRED EMBODIMENT 10 15 20 25 30 35 40 513 178> ~ - | - | ~ .- | - 7 I fi g. 1 schematically shows a chemical heat pump for the production of cooling or heat. The chemical heat pump shown consists of a first container 1 or accumulator containing a substance 2, which can exothermically absorb and endothermically desorb a sorbate, usually water. The first container 1 is connected to a second container 3, also called condenser / evaporator, via a fixed gas connection 4 in the form of a pipe connected with its ends at the top of the containers. The second container 3 acts as a condenser for condensing gaseous sorbate 6 into liquid sorbate 5 during endothermic desorbing from the solid 2 in the first container 1 and as an evaporator of liquid sorbate 5 to gaseous sorbate 6 during exothermic absorption of sorbate in the solid substance 2 in the first container 1.

The system, i.e. the interconnected internal spaces of the first and second containers 1, 3 and the gas line 4, is completely gas-tight and evacuated from all gases other than the gas 6 active in the chemical process, which is usually water vapor. The substance 2 in the accumulator 1 is in direct contact with a first heat exchanger 7 therein, which in turn can be supplied with heat from or emit heat to the surroundings via a liquid fl. The liquid 5 in the evaporator / condenser part 3 is also in direct contact with a second heat exchanger 9 in this, to or from which heat can be supplied or removed from resp. to the environment via a liquid fl fate 10.

In a preferred embodiment of an integrated heat exchanger unit for supporting the active substance, which is suitable as the heat exchanger 7 in fi g. 1 and for which unit a cross section is shown in fi g. 2a, the heat fl desolation and gas fl desolation are directed perpendicular to the large outer surfaces 21 and 21a of the heat exchanger. Both of the heat exchanger's whole, gas and heat exchanger medium impermeable parallel surfaces 21, 21a of, for example, sheet metal are connected by a structure such as a truss with channels 22 for an external heat exchanger medium through which the heat exchanger medium passes parallel to the large surfaces. At least on one surface 21 of the heat exchanger, a heat transport-increasing structure 25 of metal or other suitable heat-conducting material is arranged.

The heat conducting structure 25 has "channels" directed perpendicular to the surface 21 of the heat exchanger, which channels lie in the same direction as the heat and gas transport. The "channels" of this heat transfer increasing structure 25 are constituted by flanges which project perpendicularly from the heat transfer surface 21 and are fixedly connected to the surface 21. If the surface 25 were of copper, these ends 25 would be soldered to the surface.

The active solid is applied to one surface 21 of the heat exchanger and to the structure 25 supporting the heat transport in the form of a slurry mixture of water and substance with a higher molar content of water than the highest working molar content of the substance. By vibration of the heat exchanger / substance unit thus formed, the mixture is fixed to the surface 21 of the heat exchanger and to the structure 25 supporting the heat transport.

The substance layer is bounded on its side opposite the large surface 21 by a perforated metal structure such as a thin perforated plate 26 or a metal grid. The gas transport to / from the substance layer 23 takes place via spaces 27 in and next to a number of perforated tubular 10 15 square structures 28 arranged at the outer surface of the thin perforated the plate 26. In these spaces gas moves substantially parallel to the large surface 21 of the heat exchanger.The thin perforated plate 26 and the structure 28 at its surface can in some contexts be replaced by metal mesh structures, not shown, see more below. The net structure may comprise an inner mesh net closest to the substance and on the outside a net with coarser meshes, at the end of which is a strong net with a large thickness, which provides transport spaces corresponding to the spaces 27 for gas transport.

The mixture of substance with water is dried by gradually lowering the pressure around the heat exchange / substance unit while gradually increasing the temperature of the substance layer 23, so that excess water and water above the highest molar content leave the layer and the microchannel structure in the substance is formed and improved. This vacuum drying is carried out at the same time as the substance layer is gradually compressed by means of an externally applied force. The dried and pressed substance layer 23 is hereby integrated into a mechanically stable heat exchanger substance substance unit, which allows high heat and gas transport through the layer.

In a preferred embodiment, a substance structure 23 and a gas channel structure 27 are applied to the two opposite large surfaces 21 and 2la of the heat exchanger, thus forming a double heat exchanger / substance structure with solid substance on its large surfaces. Such double heat exchanger / substitute nicks can then be placed against each other to form a package, see ñg. 2b, with an outer tight enclosure of, for example, thin sheet metal, not shown. When the interior of the enclosure is then placed under vacuum, due to the air pressure, the walls of the enclosure will press the inside heat exchanger / substance structures especially in x-direction against each other, provided that the heat transport increasing structure 25 is not completely rigid but can give some . This is used in the drying and the final formation of the substance layer 3. The accumulator becomes self-supporting in the x-, y- and z-directions at the same time as advantageous properties of the heat and gas transport from the final formation are obtained. The structure 25 has a depth of about 10 mm in a preferred embodiment suitable for room air conditioning with day charging and night cooling. The flanges or "channels" in these structures are spaced about 5 to 10 mm apart.

The perforated plate 26 (which as mentioned above can be replaced by a grid) assists in drying and pressing against the heat transfer port increasing structure 25 and distributes the forces between the packages, so that this structure in each package becomes self-supporting. By self-supporting is meant that the entire mechanical structure, without taking into account the salt, can withstand the forces from the walls of the container when vacuum is applied. As mentioned above, however, the structure implies that the "packages" are compressed and the plates 26 are pressed hard against the ends 25 and the substance lying between them. During the casting, before the packages are placed under vacuum for drying, the substance has expanded out towards the plate 26 in the possible free space which exists between the "packages" in this state. This compresses the substance. The perforated plate or net is so meshed that crystals or sintered conglomerates of crystals of the substance are unable to pass through the holes therein. Between these crystals or conglomerates, certain gaps are maintained during the compression, which allow a sufficient gas transport.

The substances which can be used in a heat exchanger in a chemical heat pump must be 15 15 25 25 30 35 513 178 e Mar; - 9 react with water to include water bound as crystal water, which can be fairly easily broken down from the substance, at moderate temperature rises. Such substances typically include various metal salts. Substances which have been mentioned in the literature for use in chemical heat pumps or which have actually been used in heat pumps include, as mentioned above, calcium chloride CaCl 2, magnesium chloride MgCl 2, lithium chloride LiCl and sodium sulfide NazS. In order to function well in a solar-powered heat pump with water as a suitable medium, a substance within a selected, suitable temperature range such as a temperature range of about 0 - 100 ° C, where the upper temperature may in some cases be lower, must have the following properties as above: The substance must have an AT in the range of about 20 - 40 ° C. 2. The substance shall react with water vapor at phase transitions with adjacent AT. 3. The substance must at all times during the course of the process remain in a solid state, which means a melting point above 100 ° C in the preferred case. In some cases, slightly lower melting points may be allowed. 4. The substance must not sublimate. 5. The substance must be chemically stable during the reaction with water vapor. 6. The substance must not emit gases other than water vapor. 7. The substance must be mechanically stable and not change structure over time or show significant changes in its external shape when absorbing and emitting water vapor. 8. The substance must have a high reactivity with water vapor, ie react quickly, and maintain the high reactivity over time for as many cycles as possible. 9. The substance must have an energy content of at least 0.15 kWh / l and preferably more. 10. The substance must be able to be applied to heat exchanger surfaces and not show a tendency to detach from them over time.

Another requirement is that the substance must not be delicatessen. Upon discharge, a first crystal phase A is converted to a second phase B. This takes place at a certain vapor pressure. For example, if the substance is kept at 30 ° C and its melting point is 80 ° C, nothing special happens. However, when the discharge is nearing the end and all the substance in the first phase A is exhausted and converted to the second phase B, it may happen that there is still water in the evaporator and that a third phase C can be formed in vapor pressure, i.e. the conditions as regards temperature and pressure at this transition are met. Furthermore, the third phase C at 30 ° C may be liquid instead of solid. Then there is a risk of delicacy. The whole substance in solid form can now become fl surface and melt. Such a risk can also be found in the middle of a discharge, when partially or locally some part of the substance fulfills the conditions for transition to the third fl phase Phase C. When the substance is loaded by trying to cool it significantly below its normal equilibrium in order to recover so as much power as possible, in this case down to 30 ° C, no such new fl surface phases must be possible. The condition that the substance may not be delicated can be briefly expressed so that at the current temperatures there is no risk that the substance will spontaneously dissolve, when it is exposed to an unlimited amount of water vapor.

Of course, not all the criteria listed above apply to heat pumps for other applications. 10 15 20 25 30 35 40 5513 178 - - 'W' | '|' | in 10 er, although in many cases corresponding criteria can be used with adapted limit values within the temperature ranges relevant for such heat pumps.

A large number of different metal salts, which can absorb crystal water, have been studied with respect to the various properties above. In the first instance, the properties according to points 1 and 2 have been studied. In the alternative, the conditions with not too low melting rates and chemical stability according to points 3, 4 and 5 have been considered. Thirdly, the condition with not too low energy content according to point 9 has been studied. Thereafter, the reaction kinetics condition according to point 8 has been studied.

Data for various substances with respect to the properties according to points 1 - 5 are partly found in the literature. Comparison with the desired properties leaves a few substances, which meet the conditions and for which supplementary measurements have been made in the order just mentioned.

Of the known substances, sodium sulphide for use in a solar-powered heat pump is eliminated partly due to an excessive AT of 58 ° C (property 1) and partly due to lack of chemical stability (property 5). When reacting with water vapor, the equilibrium is shifted so that the formation of hydrogen sulphide H28 cannot be avoided. This gas will then be constantly present in the system and accumulate, so that an intermittent pumping out of the gas becomes necessary. If the vapor pressure of this gas, which is undesirable for the reaction, becomes too great, the reaction rate of the water vapor is affected by the substance on discharge (when the substance absorbs water) and also the reaction rate of the water vapor on charge (when the substance emits water). Calcium chloride is lost due to too low a melting point (property 3). Magnesium chloride is lost due to it having too high AT (54 ° C) in the primarily possible phase transition from 4 to 6 water molecules per molecule of chloride.

The following substances, which could be thought to have the properties 1 - 10 as above, emerged from the literature study CrFz, FeFz, FeF3, CoPz, CoF3, NiFz, LiCl, MgClz, SrClz, BaClz, CoClz, SrBrz, BaBrz, NaI, BaIZ, Mnlz , Felz, LiOH, NaOH, KOH, Sr (OH) 2, Ba (OH) 2, Na2CO3, K2CO3, LizS, MgSO3, CaSO3, CoSO3, NiSO4, FeSO4, Li2SO4, MgSO4, MnSO4, CoSO4, Mg (NO3) 2 , NiCl 2, NH 4 Al (SO 4) 2, KAl (SO 4) 2.

Strontiuric chloride SrCl2 and cobalt chloride CoCl2 could be determined to have properties 1 - 9 through literature studies. However, strontium chloride is omitted because the literature references were found to be incorrect. The stated value of AT of 20 ° C is instead close to 15 ° C.

Magnesium sulphate MgSO 4 could be determined to have all properties except 8. In tests, it was found to have inhibited the reaction rate during discharge, ie when absorbing water. This was later found to apply generally to all sulphates examined except lithium sulphate.

A number of these residual substances were omitted for various reasons in tests carried out with them: The fluorides of chromium, iron and cobalt thus proved to have large reaction mimics, ie the current processes of absorbing crystal water are very slow.

MgCl 2 has too high AT and SrCl 2 has too low AT in the current phase transitions, such as 10 15 20 25 30 35 »sis 118 of .ladxfrl, 11 already BaCl 2 had suitable AT in phase transitions with 0 - 1 H 2 O and 1 - 2 H 2 O but it has too little energy content due to the large molecular weight of barium.

BaBr2 has too little energy content in the interesting phase transition 1 - 2 H 2 O.

For BaI2, the same applies in the transition with 1 - 2.5 H2O.

MnI2 in the transition with 4 - 6 H2O has an unknown melting point and the appropriate AT = 27 ° C has never been tested. However, manganese is expensive, the energy content is theoretically too small and iodides are generally not stable, as they emit iodine gas.

FeI2 in the transition to 2 - 4 bound water molecules has a melting point of 98 ° C and its AT is unknown. However, it has never been tested, as it follows for general reasons that the energy content is too low. In addition, as mentioned, iodides are not chemically stable.

NaOH has a suitable AT but has a too low melting point of about 60 ° C and delicates extremely easily.

The same applies to KOH.

Na2CO3 and K2CO3 have too low resp. suitable AT but they have too small energy content and extremely high delicacy risk.

Sults of Mg, Ca and Co show large reaction rates.

Sulphates of Ni, Fe, Mg, Mn and Co show very strong reaction inhibitions as well as the most sulphates as mentioned above.

Li2SO4 is a good substance in most respects with a melting point exceeding 100 ° C and an AT of 20 ° C, but it has too low an energy content in the current phase transition with 0 - 1 bound water molecules.

Mg (NO3) 2 has too low AT (17 ° C) in the interesting phase transition with 4 - 6 H 2 O and also too little energy content. Vapor pressure measurements were performed on the following selected substances: Ba (OH) 2, Li 2 S, LiOH, LiCl, NaI, Sr (OH) 2, SrBr 2, NiCl 2, NiF 2. The vapor pressure measurement was performed by drying the respective substance in glass equipment at about 95 ° C in a thermostatic bath using a vacuum pump. After cooling to a low temperature, the substance was allowed to absorb a certain amount of water vapor and the vapor pressure was measured after equilibrium had occurred. The temperature was then recorded and the substance was weighed. The procedure was repeated over the entire temperature range, which is of interest for a solar-powered heat pump as above. Curves were obtained, among other things, which showed the temperature as a function of moles of water per mole of metal salt.

Results: Ba (OH) 2 was found to have three phase transitions: 0 - 0.5 H 2 O with AT> 80 ° C, 0.5 - 1.5 H 2 O with AT; 65 ° C, 1.5 - 8 H 2 O with AT = 19 ° C. Only the latter of these can be used in a solar-powered heat pump.

Li 2 S was found to have three phase transitions: 0 - 2 H 2 O with AT = 21 ° C, 2 - 3.5 H 2 O with AT = 15 ° C, 3.5 - X H 2 O with AT = 11 ° C, where X is an unknown number greater than 3.5.

Li (OH) 2 was found to have two phase transitions: 0 - 0.65 H 2 O with AT = 25 ° C, 0.65 - 1 H 2 O 10 15 20 25 30 35 40 'l "« l'f »f | - Q 51 -3 178 12 with AT = 15 ° C.

LiCl was found to have three phase transitions: 0 - 1 H 2 O with AT = 60 ° C, 1 - 2 H 2 O with AT = 30 ° C, 2 ~ 3 H 2 O with AT = 26 ° C.

NaI was found to have two phase transitions: 0 - 1 H 2 O with AT = 30 ° C, 1 - 2 H 2 O with AT = 13 ° C.

Sr (OH) 2 was found to have three phase transitions: 0 - 1 H 2 O with AT = 33 ° C, 1 - 6 H 2 O with AT = 14 ° C, 6 - 8 H 2 O with AT = 3 ° C.

SrBr2 was found to have two phase transitions: 0 - 1 H 2 O with AT = 130 ° C, 1 - 6 H 2 O with AT = 35 ° C.

NiC12 has three phase transitions according to literature information: 0 - 2 H 2 O with not measured AT, 2 - 4 H 2 O with AT = 20 ° C, 4 - 6 H 2 O with AT = 10 ° C. When measuring, however, equilibrium could not be made to adjust within a reasonable time.

NiF12 has a phase transition 0 - 4 H2 O according to literature information without any measured AT. When measuring, however, iron weight could not be made to adjust within a reasonable time.

For these and other measurements and for various other reasons, the following evaluation is obtained: Barium hydroxide Ba (OH) 2 can be used as above in the phase transition 1.5 - 6.5 H 2 O with AT = 20 ° C. However, barium hydroxide is toxic.

Lithium sulfide Li2S exhibits chemical instability and can form LiHS lithium hydrogen sulfide when taken up in water. Lithium hydroxide LiOH can be used as above in the phase transition 0 - 0.65 H 2 O and AT = 25 ° C.

Lithium chloride LiCl is found to dissolve too easily, ie the risk of delicacy is too great. The transition to the liquid state is obtained at 1.7 moles of water per mole of salt.

Sodium iodide NaI has an uptake of no more than 1 mole of water per mole of salt in the area of interest. Furthermore, NaI delicates already at 1 mole of water per mole of salt, so it is not suitable. Furthermore, iodides as pointed out above are chemically unstable and can form iodine gas.

Strontium hydroxide Sr (OH) 2 (AT = 33 ° C) also has a maximum uptake of 1 mole of water per mole of salt in the area of interest, which makes it less suitable due to its high molecular weight, which means that its energy content is too small. Incidentally, Sr (OH) 2 in its phase transition with 1-6 bound water molecules has too little AT.

Strontium bromide SrBr2 can be used as above in the phase transition 1 - 6 H 2 O and AT = 35 ° C, but there is a certain delicacy risk.

Nickel chloride NiC12 and nickel fl uoride NiF 12 do not meet the reaction rate requirement.

Li2S is eliminated despite having a suitable AT and a suitable energy content in the transition 0 to 2.5 bound water molecules due to the risk of formation of H28 as well as too low melting point and risk of deliquination.

For the remaining substances barium hydroxide, lithium hydroxide and Strontium bromide, the energy content of the interesting phase transitions was calculated. The energy content was determined to be 0.23, 0.15 resp. 0.25 kWh / l without slurry gasket.

Cobalt chloride CoCl2-2 - 6 H2O with a melting point of 86 ° C showed in tests to have very good properties with an AT of 20 - 22 ° C. The melting point may be too low in some applications. This substance is also very expensive.

Example 1a. 598 g of barium hydroxide (octahydrate) with a purity of 98%, quality "Puriss" was mixed with 194 g of water, ie 5.7 moles of H2 O per mole of Ba (OH) 2-8 H2 O, so that a semi- or thick surface mass, slurry was obtained. This contains a content of 5.7 moles above the most hydrated state of the salt. The mass thus becomes only fl surface during stirring or vibration.

It was applied at room temperature to a heat exchanger surface of the type shown in Fig. 2 during simultaneous vibration obtained from a vibrator which was of the same type used in concrete casting but of smaller size and held against the heat exchanger. The vibrations had a frequency of 25 to 50 Hz. The substance then flowed easily and settled in the spaces in the heat exchanger structure. A thin sheet metal casing was placed around the heat exchanger and connected to a vacuum pump. This had to pump out air and water while simultaneously heating. Typical data were that the pumping was done down to the equilibrium vapor pressure of the substance of about 20 mm Hg at 20 ° C for about 240 minutes with a steady temperature increase from room temperature to 80 ° C, when the pumping out was complete. The tight sheet metal cover was removed. The mass was found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken which was found to contain hydroxide of the formula Ba (OH) 2-1.5 H 2 O. The density of the pulp was determined to be 861 g / l, which is considerably greater than the density of the corresponding dry-packed substance, which for this amount of crystal water is 619 g / l, see Example 1b. Despite the high degree of packing, as shown by the measured density of 861g / l, the porosity is good. The density of crystalline Ba (OH) 2-1.5H 2 O is 1.37 g / l, so that the remaining porosity still constitutes 36% of the volume. The heat exchanger with the stuck substance fi ck then perform 10 cycles with absorption of water and heating to 80 ° C to remove water placed in a heat pump according to ñg. 1. The mass showed no signs of detachment from the surface of the heat exchanger - no cracks or cavities appeared at this surface of the substance. The mass absorbed and released water without reaction inhibitors with time as follows: fully charged after 4 hours, fully discharged after 30 hours.

The reaction rate was maintained without appreciable change during all cycles. The effective value of the energy content was measured at 0.32 kWh / l.

Example lb. 430 g of barium hydroxide (octahydrate) with a purity of 98%, grade "Puriss" was ground to a fine-grained powder and sieved through a 300 mesh steel cloth. The sieved powder was applied at room temperature under vibration in the same manner as in Example 1a on the heat exchanger surface according to FIG. 2. The substance then settled in the spaces in the heat exchanger structure. The substance was sintered by drying and heating to a mass in the same manner as in Example 1a. The mass was then found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken which was found to contain hydroxide of the formula Ba (OH) 2-1,5 H 2 O. The density of the pulp was determined to be 619 g / l, giving a porosity of 50% by volume of crystalline Ba (OH) 2-1.5H 2 O. The heat exchanger with the adhering substance was then allowed to perform 10 cycles with absorption of water and heating to 80 ° C to remove water placed in a heat pump according to Fig. 1. The mass showed signs of dropping from the surface of the heat exchanger. The mass absorbed and gave off water without reaction inhibitors, but the time to obtain full charge was now extended to 6 hours. The time until complete discharge was 10 - 40 hours. The reaction rate was maintained without appreciable change during all cycles. The effective value of the energy content was measured to be 0. , 23 kWh / l.

Example 2a. 670 g of CoCl2 ~ 6H2O with purity 99% and quality "pro analysis" were mixed with 127 g of water, ie 1.75 moles of H2 O per mole of CoCl2-6H2O, so that a semi- or thick-flowing mass, slurry was obtained. This means a content of 1.75 mol over the most hydrated state of the salt. The mass was applied at room temperature under vibration in the same manner as in Example 1a on the heat exchanger surface according to ñg. 2. The substance then became slightly fl surface and settled in the gaps in the heat exchanger structure. The substance was sintered by drying and heating to a solid mass in the same manner as in Example 1a. The mass was then found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken, which was found to contain hydrated salt of the formula CoCl2-2H2O. The density of the solid mass was measured to be 900 g / l, which is greater than the density of 635 g / l of the corresponding dry packed substance, see Example 2b. The pulp has a porosity of 33% compared to the crystalline form of the corresponding hydrate, which has a density of 1.34. The heat exchanger with the adhering substance then did not perform 10 cycles with absorption of water and heating to 80 ° C to remove water, when placed in a heat pump according to fi g. l. The mass did not show any signs of detachment from the surface of the heat exchanger. The mass absorbed and gave off water without reaction inhibitors. The effective value of the energy content was achieved to 0.25 kWh / l.

Example 2b. 473 g of CoCl2 ~ 6H2O (hexahydrate) of 99% purity and of "pro-analysis" quality were ground to a granular powder and sieved through a 300 mesh steel cloth. The sieved powder was applied at room temperature under vibration in a circular manner as in Example 1a on the heat exchanger surface according to fi g. 2. The substance then settled in the gaps in the heat exchanger structure. The substance was sintered by drying and heating to a solid mass in the same manner as in Example 1a. The mass was then found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken, which was found to contain hydrated salt of the formula CoCl2-2H2O. The density of the solid mass was reached to 635 g / l. The pulp has a porosity of 33% compared to the crystalline form of the corresponding hydrate, which has a density of 1.34.

The heat exchanger with the adhering substance was then allowed to perform 10 cycles with absorption of water and heating to 80 ° C to remove water, when it was placed in a friend pump according to ñg. The mass showed signs of dropping from the surface of the heat exchanger. The mass absorbed and released water without reaction inhibitions. The effective value of the energy content was measured at 0.21 kWh / l.

Example 3a. 302 g of LiH-0.65H2O with a purity of 98% and of the quality "purum" were mixed with 167 g of water, which corresponds to 1.1 mol of H2 O over the most hydrated state of the salt, so that a semi- or thick-flowing mass, slurry was obtained. The mass was applied at room temperature under vibration in the same manner as in Example 1a on the heat exchanger surface according to fi g. 2. The substance then became slightly fl surface and settled in the spaces in the host exchange structure. The substance was sintered by drying and heating to a solid mass in the same manner as in Example 1a.

The mass was then found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken out, which was found to contain salt LiOH without crystal water. The density of the solid mass was reached to 513 g / l, which is greater than the density of 487 g / l of the corresponding dry packed substance, see Example 3b The pulp then has a volume porosity of 67% compared to the crystalline form of the salt, which has a density of 1.46 The heat exchanger with the solid substance was then allowed to perform 10 cycles with absorption of water and heating to 80 ° C to remove water , when it was placed in a heat pump according to ñg. 1. The time for complete charging was 4 hours while a complete discharge took 24 hours.

The mass showed no signs of detachment from the surface of the heat exchanger. The mass absorbed and released water without reaction inhibitions. The effective value of the energy content was measured at 0.16 kWh / l.

Example 3b. 287 g of 98% pure 98% LiH-0.65H 2 O were purified to a fine powder and sieved through a 300 mesh steel cloth. The sieved powder was applied at room temperature with vibration in the same manner as in Example 1a of the surface according to Fig. 2. The substance then settled in the spaces in the heat exchanger structure.

The substance was sintered by drying and heating to a solid mass in the same manner as in Example 1a. The mass was then found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken out, which was found to contain the salt LiOH without crystal water. The density of the solid mass was measured at 487 g / l, which corresponds to a volume porosity of 71% compared to the crystalline form of the salt. The friend changer with the stuck substance fi ck then perform 10 cycles with absorption of water and heating to 80 ° C for removal of water, when it was placed in a friend pump according to Fig. 1. The time for complete charging was as for the in the slurryform applied the salt to 4 hours while the time for a complete discharge was increased to 27 hours. The mass showed very weak signs to drop from the surface of the heat exchanger. The mass absorbed and gave off water without reaction inhibitions. The effective value of the energy content was measured at 0.15 kWh / l.

Example 4a. 883 g SrBr2-6H2O with purity 99% and of quality "puriss.p.a." was mixed with 132 g of water, corresponding to 2.48 mol of H 2 O over the most hydrated state of the salt, so that a semi- or thick-surface mass, slurry was obtained. The pulp was applied at room temperature with vibration in the same manner as in Example 1a on the heat exchanger surface according to Fig. 2. The substance then became slightly surface and settled in the spaces in the heat exchanger structure. The substance was sintered by drying and heating to a solid mass in the same manner as in Example 1a.

The mass was then found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken, which was found to contain the hydrated salt SrBrz-H 2 O. The density of the solid mass was measured at 1492 g / l, which is greater than the density of 1044 g / l of the corresponding dry packed substance, see Example 4b. The pulp then has a volume porosity of 17% compared to the crystalline form of the salt, which has a density of 1.79. The heat exchanger with the adhering substance was then allowed to perform 10 cycles with absorption of water and heating to 80 ° C to remove water, when it was placed in a heat pump according to Fig. 1. The time for complete charging was 4 hours while a complete discharge took 16 hours.

The mass showed no signs of detachment from the surface of the heat exchanger. The mass absorbed and released water without reaction inhibitions. The effective value of the energy content was measured at 10 15 20 25 30 35 40 513 178 || ". | \ R '| ~' t 16 0.32 kWh / l.

Example 4b. 618 g SrBr2-6l-I2O with purity 99% and of quality "puriss.p.a." mortar to a granular powder and sieved through a 300 mesh steel cloth. The sieved powder was applied at room temperature under vibration in the same manner as in Example 1a on the friend exchange surface according to fi g. 2. The substance then settled in the spaces in the heat exchanger structure.

The substance was sintered by drying and heating to a solid mass in the same manner as in Example 1a. The mass was then found to be well sintered and firmly attached to the surface of the heat exchanger. A piece of pulp was taken, which was found to contain the hydrated salt SrBrZ-H 2 O.

The density of the solid mass was measured at 1044 g / l, which corresponds to a volume porosity of 24% compared to the crystalline form of the salt. The heat exchanger with the adhering substance was then allowed to perform 10 cycles with absorption of water and heating to 80 ° C to remove water, when it was placed in a heat pump according to fi g. The time for full charge was 4 hours while the time for full charge was extended to 20 hours. The mass showed signs of detachment from the surface of the heat exchanger. The mass absorbed and released water without reaction inhibitions. The effective value of the energy content was measured at 0.23 kWh / l.

CaCl2 is an example of a substance which has suitable AT values and a sufficiently high energy content but which cannot be slurried. The melting point of the phase transitions useful in this salt is lower than that required to regenerate the substance after filling the slurry in the heat exchanger structure.

This is the case for many of the above-mentioned sorted substances, such as LiCl, LiBr, CaBrz, FeCl 3, NaOH, KOH, etc. It is the sum of all the above-mentioned required properties that makes a substance both function in the process and be suitable for filling and generation according to the slurry method. Most substances can be slurried but not counteracted after the application of the slurry.

In the application of solar-powered air conditioning, the reactor part and the condenser / evaporator part can suitably be placed within one and the same physical space or housing, see the schematic cross-section in Fig. 3a. They can also be made with circular or cylindrical geometry or symmetry, although some advantages of the planar structure according to fi g. 2a and 2b may be sacrificed.

A common tank 31 thus encloses the entire system, so that a complete hermetically evacuated chemical heat pump is obtained therein. The tank 31 is internally divided into two separate compartments. A first upper compartment 32 houses the accumulator and constitutes a reactor and in a second lower compartment 33 there is a condenser / evaporator. In the accumulator part 32 there is a friend changer 34 placed concentrically along the inner periphery of the tank 31. The heat exchanger 34 can be simple or as shown in fi g. 3a consist of fl your concentric units 34a, 34b seen from the center of the tank, so that each unit has the shape of a cylinder ring. Each unit in the heat exchanger 34 is of the fl type and includes vertically standing slats 35, see fi g. 3b, which thus lie in a plane through the axis of the cylindrical shape and are solar-mounted on the heat carrier 36's heat exchanger, see the perspective view in fi g. 3c. These heat carriers 36 consist of horizontal, parallel-connected pipe loops, which form circular pipe loops also 10 15 20 25 30 35 40 3513 178 || ". | Tr 't 17 with the same axis as the other parts of the heat pump. Around the heat exchanger units or - the packages 34 are net 37 stretched on both the outside and inside and over their bottom.The substance 38 has been filled between the net walls 37. It is further assumed that the substance 38 molded in between the slats 35 has free gas fl or gas-free fl via a channel 45 parallel to the slats. see fi g 3d.

The channels 45 can be provided by a coarse net on its two surfaces or sides having mesh nets, the coarse net being bent to a suitable shape and being applied with support to the ends 35. The coarse net forms the channels 45 themselves while the narrow net prevents substance in the slurry form from flowing into the channels when filling the substance from above.

In these cylindrical heat exchangers, the surfaces of the vanes 35 correspond to the large outer surface 21 of the heat exchanger for that of the. G. 2a showed the flat case. The heat conduction in the substance is namely so low that the fl ends connected to the pipe with the protective carrier in this context can be considered to have the same temperature and the same temperature as the pipe. The substance layers between the fls and the channel 45 are made with a thickness of about 10 mm, ie in the direction perpendicular to the ochs and in the circumferential direction in the entire heat exchanger ring. No heat-conducting structure corresponding to the structure 23 is present in the cylinder symmetry design. Such is required only at very high effects. In an application with room temperature, charging can take at least 6 hours while discharging takes place for perhaps up to 12 hours. Tests show that in this case 10 mm thick layers directly against metal surfaces without any additional heat-conducting structure are sufficient and that the metal surfaces do not have to be in direct contact with the heat-carrying medium but can be of the lamella type such as the 35 ends 35. Some simple compression of inserted substance by evacuating the tank can not be obtained in the cylindrical symmetrical case.

For a heat exchanger designed as fl your concentric cylinder rings according to fi g. 3a, the central part of the tank cannot be used, which gives a certain dead volume. For a case in which half the radius of the tank is used for the heat exchanger packages, it will be appreciated that these occupy 3/4 of the volume of the tank. However, the remaining space does not need to be filled with a heat exchanger package, but this space is used for gas transport and excellently prevents pressure losses in the system, between the reactor and the condenser / evaporator.

If you instead place a friend-changer / substance package with an external shape as a rectangular block with a square cross-section in a cylindrical tank and thereby use the central area of the tank to the maximum, you also get a degree of filling of 3/4 of the tank volume and the remaining the four spaces are good gas transport spaces.

Inlet and outlet 39 for the heat exchanger supply resp. removes heat via the external heat exchanger medium. Between the accumulator part 32 and the condenser / evaporator part 33 there is a partition 40 with a hole located centrally in the tank 41. The condenser / evaporator part 33 consists of a cylindrical plate protection exchanger 41 connected to inlets resp. outlet 13 for supply resp. removal of heat via an external medium. The liquid, which in this case is water 42, fills the bottom of the tank 31. A capillary suction material has been applied to the surfaces of the heat exchanger 41 at least on one side. When the accumulator is delivered to the user, all the water bound in the substance is in the accumulator part 32. The accumulator is discharged. 10 15 20 25 30 35 40 513 178 lrïiïi fl 't 18 In an intended application for air conditioning, for example at night, the function is as follows. Hot water produced in a solar collector during the day is supplied to the heat exchanger 34 of the accumulator 32 via the inlet and outlet connections 39. At the same time, water, which is exchanged with the outdoor air, is supplied to the heat exchanger 41 of the condenser / evaporator 33 via the inlets resp. the outlets 43 thereof for external medium. The vapor pressure of the substance 38 then rises and eventually reaches a pressure which is higher than the vapor pressure of the water at the heat exchanger 4 of the condenser / evaporator 33. Steam then flows from the substance 38 to the heat exchanger 41 of the condenser / evaporator 33 and condenses to water 42 The process continues until all the water of the substance used in the used phase transition has passed. All water 42 has then condensed in the condenser / evaporator part 33 and the condensation barrier has been wiped away via the heat exchanger 41 to the outdoor air with the liquid fl through the heat exchanger 41.

In the evening, the heat exchanger 41 of the condenser part / evaporator part 33 is connected via liquid fl through it to the room heat exchanger of the house, at the same time as the heat exchanger 44 of the accumulator part 32 is connected via its liquid flow to an outdoor heat exchanger. The substance 38 is then kept at the same temperature as the outdoor air, whereby its vapor pressure remains very low. Due to the low vapor pressure, water vapor now flows from the heat exchanger 41 of the condenser part / evaporator part 33 to the substance 38 of the accumulator part 32.

The rooms are getting cold. The supplied steam generating energy accompanies the steam and is released together with bound chemical energy in the substance 38 of the accumulator part 32, and is carried away through its heat exchanger 34 to the outdoor air via the liquid flow 39 between the heat exchanger 34 and the outdoor heat exchanger.

In order for the function of the entire air conditioning system to be fully understood, its mode of operation must be further explained with reference to the schematic diagram in fi g. 4. The chemical heat pump is in fi g. 4 divided into accumulator 32 and condenser / evaporator 33. External components in the complete air conditioning system consist of a solar panel 53, outdoor heat exchanger 54, room cooler 55, accumulator pump 56, condenser / evaporator pump 57, accumulator valve 58 and condenser / evaporator valve 59.

When charging during the day, the accumulator valve 58 is set so that the accumulator pump 56 drives the flow from the solar panel 53 to the accumulator 32. At the same time, the condenser / evaporator valve 59 is set so that the condenser / evaporator pump 57 drives the flow from the outdoor heat exchanger 54 through the condenser / evaporator 33. the accumulator 32 then emits water vapor to the condenser / evaporator 33, until the substance is fully charged with absorbed water. During the evening, the accumulator valve 58 is set so that the accumulator pump 56 drives the flow through the outdoor heat exchanger 54. At the same time, the condenser / evaporator valve 57 is set so that the condenser / evaporator pump 57 drives the flow from the room coolers 55 through the condenser / evaporator 33.

In this case, the substance is kept in the accumulator 32 at outdoor temperature, whereby the vapor pressure over the substance becomes significantly lower than the vapor pressure in the evaporator / condenser 3, which is "heated" with the pipe coolers 55. Water vapor now flows from the condenser / evaporator 33 to the substance in rtwq - 51-3 178 19 the accumulator 32. Vapor formation energy is then transported from the room coolers 55 to the substance in the accumulator 32 and on to the outdoor heat exchanger 54. The rooms are cooled and the process continues until the substance in the accumulator 32 has absorbed all water in the phase transition for the substance used.

The fact that the tank enclosing the accumulator and evaporator / condenser is of cylindrical shape is advantageous for strength reasons. Furthermore, the heat exchangers can advantageously be designed as essentially conventional lamella heat exchangers for liquid / gas with a straight pipe loop. This provides a heat exchanger package with an outer rectangular shape. The heat transfer in such packages is determined by how tightly the slats are placed. The packages can, for example, have 400x500x50 mm. The packages are thus thin to facilitate gas transport to and from the substance. To some extent, in such packages it is possible to deviate from the rule that heat and gas must flow in the same direction. The packages correspond to the cylinder rings according to ñg. 3a - 3d except that the tube 36 is straight, the ends 35 are all parallel and the channels 45 for gas transport are missing. A number of such packets enclosed in networks can be connected in parallel and filled with substance from above as well as in the embodiment in fi g. 3a.

This proposed chemical heat pump can also be used for direct cooling purposes. It is quite possible to cool smaller spaces such as refrigerators or cooler bags for a long time. A cooler bag for transporting food or medicine and with a capacity for fl your 24-hour function will now be described with reference to fi g. 5.

The i ñg. The chemical heat pump shown in Fig. 5 is integrated with the lid of the cooling bag, which is constructed in a manner similar to the tank 31 in one. 3a. The lid is thus hollow and in the inner space in the upper part of the lid is the accumulator 71, which is attached to the outer, upper surface of the lid, and in the lower part of the inner space the condenser / evaporator 72 is attached to the lower, towards the cooling bag cold space facing surface. The accumulator 71 and the condenser / evaporator 72 consist of two flat, low metal containers preferably made of thin stainless steel, connected to each other via a centrally located tubular connection 73 for gas transport between the accumulator 71 and the condenser / evaporator 72. These are thermally separated from each other by means of a layer of heat-insulating material 74 located between the accumulator part and the condenser / evaporator part. The accumulator 71 is further divided into two spaces, an upper space containing the substance 75 and a heat exchanger 76 and a lower space containing supports 77 made of perforated sheet metal. The two spaces are separated by a mesh net 78. The flange heat exchanger 76 distributes heat from an electric heating cartridge 79 plugged into a heat exchanger tube 80 connected to the ns ends of the vär heat exchanger 76, and together with the support ns ends 77 in the lower part against the construction. The condenser part / evaporator part 72 is filled with perforated supports fl also 81 with the task of stabilizing the construction against the force of the air pressure and conducting heat. Between the support members 81 a capillary-absorbing material 82 has been arranged, for instance a cellulosic material, in which the water 73 is prevented from moving freely. Evacuation of the lid's interior space is carried out via a "tip-off" nipple 84 of the type used for closing, for example, refrigeration systems.

The construction is made as two low stainless steel boxes welded together via the tubular central connection 73. The heat exchanger 76, the net 78 and the supports 77, 81 are placed in the boxes and the substance 75 is filled in the accumulator 71. Stainless steel lids 85, 86 are welded to the two parts by means of welding joints 87, 88 around the periphery, of which one lid 85 faces upwards and forms the upper surface of the cooler bag lid and the other lid 86 faces The cooler lid is electrically charged before use by means of the built-in heating cartridge 79. The underside of the lid, which faces the space to be cooled and which in this case serves as a condenser, can advantageously be placed, for example, on a sink in a kitchen. An insulating hood is placed over the accumulator part of the lid to reduce heat loss.The charging is intended to be carried out in a few hours.The lid is ready for use after cooling and is then placed on the cooler bag. there is no shut-off valve, the lid must be used immediately. To keep the lid charged, in this case the heating cartridge must be connected. Of course, it is also quite possible to carry out the construction with a valve in the connecting pipe 73. Such a valve must then be made with magnetic force transfer from the outside, since no normal valves are able to meet the very high tightness requirements.

Thus, effective substances have been described. A method for producing structures containing a substance and structures has been described, which gives very good heat transport and diffusion in an applied layer of the substance, a good mechanical stability a layer of the substance and a high energy density of the substance. Designs of a nuclear heat pump suitable for applications such as air conditioning, cooler bags and refrigerators have also been described.

Claims (17)

10 15 20 25 30 35 40 51-3. 178 'Pai' f-HI 1 21 PATENTKRAV A chemical heat pump comprising a first container (1, 32, 71) containing an active solid (7), a second container (3, 33, 72) and a connecting line (4, 73) between the first container and the second container , so that the inner spaces of the containers and connecting line form a closed system, and further comprising a volatile liquid (6) in the closed system, characterized in that a substance having an temperature difference AT of substantially 20 - 40 ° C at a pressure equilibrium between active solid and the volatile liquid within a temperature range of substantially 0 - 100 ° C for the chemical heat pump and that the volatile liquid consists of water. Chemical heat pump according to claim 1, characterized in that the active solid substance within the temperature range reacts with the gas phase of the volatile liquid at at least two phase transitions with adjacent AT. Chemical heat pump according to one of Claims 1 to 2, characterized in that the active solid has an energy content calculated as evaporation energy amounting to at least 0.15 kWh / l of the active solid, preferably at least 0.20 kWh / l of active solid. Chemical heat pump according to any one of claims 1 to 3, characterized in that the active substance comprises a substance selected from CoCl 2, Ba (OH) 2, LiOH and SrBrz. Chemical heat pump according to one of Claims 1 to 4, characterized in that the active solid is present in a porous state. Chemical heat pump according to one of Claims 1 to 5, characterized in that the active solid is present in a porous state with a volume porosity of at least 15%, preferably 35%, relative to the active solid in a completely compressed state or in crystal state. Chemical heat pump according to one of Claims 1 to 6, characterized in that the first container comprises an at least partially heat-conducting wall and in that the active substance is applied to the at least partially heat-conducting wall as a layer with a substantially constant thickness and with an outer surface, which layer has such a thickness that the volatile liquid in the evaporated state is able to interact from the outer surface with all parts of the active substance. Chemical heat pump according to Claim 7, characterized in that the layer has a thickness of at most 10 mm. Chemical heat pump according to one of Claims 7 to 8, characterized in that the active substance in the layer is in a porous state. Chemical heat pump according to one of Claims 7 to 9, characterized in that the active substance in the layer is present in a porous state with a volume porosity of at least 15%, preferably 35%, relative to the active solid in a completely compressed state or in crystal state. Chemical heat pump according to one of Claims 7 to 10, characterized in that there are substantially parallel slit-shaped channels in the layer with a direction perpendicular to the heat 51.1 »1” 78. | -. | -F, - | . 22 conductive wall to allow the volatile liquid to enter the channels to interact with the substance. Chemical heat pump according to one of Claims 7 to 11, characterized in that heat-conducting thin or narrow material, in particular wire-shaped or disc-shaped heat-conducting material, which is attached to the heat-conducting wall, penetrates the layer. Chemical heat pump according to claim 12, characterized in that the heat-conducting thin or narrow material lies substantially perpendicular to the surface of the heat-conducting wall. Chemical heat pump according to one of Claims 1 to 13, characterized in that the active substance is arranged in the first container in the form of a dried slurry-like mixture of the substance with excess of the volatile liquid. Chemical heat pump according to claim 14, characterized in that the active substance is placed in the first container in the form of a not only dried but also gradually heated slurry-like mixture of the substance with excess of the volatile liquid. Chemical heat pump according to one of Claims 14 to 15, characterized in that the active substance is arranged in the first container in the form of an even compressed slurry-like mixture of the substance with excess of the volatile liquid. Chemical heat pump according to one of Claims 14 to 16, characterized in that the active substance is arranged in the first container in the form of an evenly vibrated slurry-like mixture of the substance with excess of the volatile liquid.