DE2808464A1 - Storage of heat for subsequent use - using reversible chemical reaction with greatly reduced ambient losses - Google Patents

Abstract

The periodic storage and discharge of heat uses at least one heat transformer contg. a working medium. This undergoes an endothermic reversible reaction to give a solid and a gaseous component. In the storage phase, heat is added to the absorber/releaser and the medium yields the gaseous component, which flows into the condenser/evaporator section. Here it condenses releasing heat. In a heat release mode, the condensate in the condenser/evaporator section is evaporated. This then releases heat in the absorber/release zone by reacting with the solid phase which absorbs it. Solar or electric energy can be used as sources of heat. The energy released by condensation is released to atmosphere or to a latent heat store. The heat released during the release mode is used for water heating or space heating. For use in storing solar energy or electrical energy during the night.

Description

Method and arrangement for periodic storage

and release of heat The invention relates to a method for periodic Storage and release of heat using at least one heat transformer with a working fluid enclosed in it, which is caused by an endothermic, reversible Reaction can be converted into a gaseous and a solid component. The invention further relates to a heat pump arrangement for carrying out this method.

There are latent heat storage systems known as earthenware or hot water storage tanks work or use the heat of fusion of various salts for storage. This latent heat storage is disadvantageous because the storage with large losses is connected and the heat at most at the same temperature level as the Storage can be regained.

A heat storage device would be desirable, in particular for storing Solar heat and / or electrically generated heat, e.g. B. as night storage heater.

To also low-temperature heat, for example from the low-lying Sun, still to be able to use, should be the collected and stored heat can be released again at a higher temperature level.

Finally, the problem should also be proportional to the storage time increasing heat losses from conventional heat storage systems can be avoided.

Now pairs of substances are known, which in the temperature range from about 0 - Enter 1000 C reversible chemical reactions, being the heat of reaction is bound or released depending on the direction of the reaction. It is now possible to use such endothermic reactions for the storage of heat.

The substances mentioned include the halides of the alkali and alkaline earth metals with ammonia, methylamine, ethylamine, etc.

The one for the technical evaluation for the chemical heat storage Working materials in question are pairs of substances that act as solid, powdery salts are present and in which a gaseous component is expelled by the supply of heat can be. These are especially those gaseous components or absorbates of Interest in the expulsion pressure and one not too deep below the expulsion temperature lying condensation temperature enter their liquid phase. In the condensed In this state, such absorbates can be stored in a space-saving manner without heat loss.

The method according to the invention consists in that in a storage phase the working equipment housed in the expeller-absorber part of the heat transformer Heat is supplied to release the gaseous component that enters the condenser-evaporator section of the heat transformer flows where it condensed with release of heat becomes ~ and that the condensate in the condenser-evaporator part is in a depletion phase is evaporated and releasing heat of reaction in the expeller-absorber part is bound again to the solid component.

The heat pump arrangement for carrying out the method is according to the invention characterized by at least one self-contained heat transformer, consisting of an expeller-absorber part and a condenser-evaporator part connected to it, whereby the working fluid is housed in the heat transformer without loss.

The released heat can be used directly as useful heat for space heating or domestic water heating can be used.

However, it can also go to the next level in one of several levels existing heat pump arrangement. This makes it possible to adjust the temperature level to further increase the useful heat.

It is also useful to have two periodically operating heat pump arrangements (single or multi-stage) to be coupled with each other and operated out of phase. Alternately, the an arrangement of heat stored, while the other arrangement extracts useful heat, thereby creating continuity the useful heat output.

Exemplary embodiments are now given below with reference to the drawings the invention explained in more detail. They show: FIG. 1 schematically a heat pump arrangement with a heat transformer for the alternative storage of solar heat or electrically generated heat, Fig. 2 the pressure and temperature conditions in the heat transformer According to FIG. 1 when storing solar energy, FIG. 3 that of FIG. 2 Pressure / temperature diagram for the release of stored heat from the heat transformer according to Fig. 1, Fig. 4 schematically a multi-stage heat pump arrangement with three Heat transformers during the exchange phase, Fig. 5 schematically part of the arrangement according to FIG. 4 during the heating or cooling phase, with a Heat transformer for heating and another heat transformer for air conditioning are used, Fig. 6 schematically a part of the arrangement according to FIG. 4, wherein two heat transformers are connected in parallel for winter operation, FIG. 7 the pressure and temperature conditions during the exchange phase of the multi-stage The heat pump arrangement according to FIG. 4, FIG. 8 shows the pressure and temperature conditions during the heating phase in the multistage heat pump arrangement according to FIG. 4, FIG. 9 shows the heat flow diagram of the multi-stage heat pump arrangement according to FIG. 4, FIG. 10 the working range of a heat transformer, in terms of the storage temperature and the outside temperature, whereby the respective process pressure is entered as a parameter is, 11 shows the working area of a heat transformer, in function the useful heat temperature and the Absorbatsverdampfung Temperatur, where again the respective process pressure is entered as a parameter, FIG. 12 shows a section through an embodiment in which a heat transformer and a molten salt latent storage are combined to form an operating unit, FIG. 13 shows the floor plan of the operating unit according to FIG. 12, FIG. 14 shows a section along the line XIV-XIV according to FIG. 12, wherein the heat exchanger absorber plate is shown, Fig. 15 is a side view of the Heat exchanger absorber plate according to FIG. 14 in the direction of arrow XV, FIG. 16 schematically shows the structure and routing of the heat transformer according to FIG Fig. 12 and 17 shows a single-stage heat pump arrangement, with two heat transformers are coupled together and alternately in the Storage phase or

work in the heating phase.

In the heat pump arrangement shown in FIG. 1 with the heat transformer 1 it can be a stand-alone system or the first stage of a multi-level plant. The substance pair methylamine-calcium chloride serves as working medium A, which is enclosed in the encapsulated heat transformer 1. The latter exists from an expeller-absorber part 2, which is connected to a condenser-evaporator part 3 communicates. The solar heat collected by the solar collector 4 is via an intermediate medium, for example air or water, by means of the heat exchanger 5 is supplied to the working medium A in the expeller absorber part 2. This will result in the following endothermic reversible reaction triggered: 2 6CH3NH2 + 9A = CaC12.2Cll3N112 + 4CII Nll The gaseous methylamine 4CH3NH2 (component A1) flows into the condenser-evaporator part 3, where it is condensed while the solid substrate (component A2) remains in the expeller absorber part 2.

The heat of condensation released during the condensation of methylamine A1 q. is by means of the heat exchanger 6 1 to the environment, for example to the Outside air L, released.

The available solar energy is not sufficient for the complete expulsion the methylamine, the remaining expulsion with electrical energy, z. B. with the electric heater 7 and the heat exchanger 8 take place.

Since temperature and pressure are higher during expulsion with electricity can assume, is expediently also obtained at a higher temperature Condensation heat is not given off to the outside air, but via the heat exchanger 9 is supplied to the additional memory 10 acting as a latent memory. In the additional storage 10 there may be water that is heated, or it could have melted a salt will. The heater 7, the additional memory 1 and the corresponding heat exchangers 8 and 9 are shown in dashed lines in FIG. 1 to illustrate the process sequence suppose, for example, that the sun heats the intermediate medium in the collector 4 to 450 C and the temperature of the outside air is 5 C. In first As an approximation, the heat losses are neglected. As for the heat exchange process sufficiently long times are available, a temperature difference of 'O C considered to be feasible for all heat transfers. These ratios are shown in the pressure / temperature diagram log p - 1 / T (Fig. 2), with A being the voltage curve of the working medium, with A1 the voltage curve of the methylamine and with A and Alc the corresponding expulsion or condensation points are designated. That Methylamine A1 is released at 400 C and condenses at 100 C, with the heat of condensation is released to the environment at 5 ° C. The process proceeds at a constant Pressure of about 2 bar from automatically.

During the expulsion process, about 4 molecules of methylamine A1 are released the saturated compound A is released. Per kg total weight of the work equipment qA = 242 kcal heat is bound.

Since the molecular weight of the saturated working fluid is 296, the one of methylamine is 31, the weight loss on expulsion is: = = 4. 31/29 () = 41, ° Based on 1 kg total weight of the saturated work equipment Let the solar energy bound during expulsion (242 kcal) be defined as 1 5.

The heat of condensation qC of the methylamine is 201.6 kcal / kg at 100 C. The amount of heat released into the environment during the condensation of the methylamine is: In relation to the originally bound solar heat, 34.9% is released into the outside air and the rest is chemically bound.

The storage process is largely self-regulating and will triggered as soon as heat to expel the methylamine to the heat transformer is fed.

As can be seen from the log p-l / T diagram of FIG the temperatures of the expulsion (400 C) and the condensation (100 C) a process pressure from 2 bar.

Compared to the direct use of solar heat, for example for heating purposes, about Y3 of the energy is lost during storage. For that can the chemically bound energy can be stored for a long time without loss and can be used again if necessary. In addition, the heat pump effect can also increased Low-temperature solar heat is used and stored and then at a higher level Temperature can be transformed.

In order to remove the chemically bound heat, the Condenser-evaporator part 3 evaporated methylamine condensate. The gaseous one Methylamine A1 then reaches the expeller absorber part 2, where it is again with the absorber A2 connects, whereby useful heat is released by the exothermic reaction.

The unstoring process is shown in the log p − 1 / T diagram in FIG. 3 recorded.

In order to obtain useful heat, for example from 530 C, the transformation process carried out in the opposite direction at a pressure of 5.4 bar. If solar energy is available for the evaporation of the liquid methylamine, this can be done at 470 C can be used for this. Otherwise, part of the heat of reaction or Heat from the additional storage 10 needed for evaporation. The methylamine condensate evaporates at 370 G (point A1v) and absorption takes place at 58 ° C (point Ab).

Assuming that the heat of evaporation is covered by the absorption process, the amount of heat remains: This amount of heat can be used directly for heating purposes or for hot water preparation, for example.

From the originally collected at a temperature of 450 C. Solar energy is still around 65% available for use, whereby the heat pump effect increases the temperature to the more valuable level of 530 C has been achieved.

The heat pump arrangement described can be used as a pure solar heat storage heater, as a pure night-time storage heater or conveniently as a combination of both can be used. But it can also be used as the first stage of an alehr pump arrangement to serve.

A multistage heat pump arrangement will now be described below with reference to FIGS. 4 to 6 explains in which the heat transformer 1 according to FIG. 1 in a slightly modified form Execution is coupled with two further heat transformers 31 and 41, around To provide heating at a higher temperature or cooling heat for the air conditioning.

All three heat transformers 1, 31, 41 are encapsulated, so that the work equipment they contain cannot escape. The heat supply and discharge between the working equipment takes place via heat exchangers in the expeller-absorber parts 2, 32, 42 or the condenser-evaporator parts 3, 33, 43 of these heat transformers.

While in the first heat transformer 1 still methylamine-calcium chloride (Working fluid A) is used in the other two heat transfer converters 31, 41 methylamine lithium chloride (working fluid B) loaded.

In the function of the multi-stage heat pump arrangement, three different work phases can be distinguished: a storage, an exchange and a heating or a cooling phase.

In the storage phase, as already in the description of Fig. 1 has been mentioned, some of the solar heat is bound in the first heat transformer 1, possibly also condensation heat of higher temperature in the additional storage 10 submitted. During the exchange phase, which is shown in FIG is shown, the energy stored in the first heat transformer 1 is released and serves to expel the gaseous components from the working equipment of the Heat transformers 31 and 41. For this purpose, the expeller absorber part 2 is via the Heat exchangers 11, 12 are connected to the expeller-absorber parts 32 and 42.

To release the heat in the heat transformer 1 can, provided during the exchange phase the sun shines, its heat over the collector 4 and over the heat exchanger circuit 13 are fed to the condenser-evaporator part 3, to vaporize the liquid methanyl. Otherwise you can do this in the additional memory 10 existing heat via the circuit 14 or part of the heat of reaction the circuit 15 are used for this.

The heat of condensation from the working equipment B of the heat transformers 31 and 41 released, gaseous component B1 is through the heat exchanger 16, 17 and the circuit 18 are released to the outside air L. Subsequent to the Exchange phase there is still the possibility of using the stored energy supply with electrical energy through continued expulsion with the Heating 19 and the heat exchangers 20 and 21 to supplement. During the expulsion The condensation heat from the condenser-evaporator parts is generated with electrical energy 33, 43 stored in the container 10 via the circuit 22.

During the heating or cooling phase, which is shown in FIG. 5, the condensate is evaporated in the two condenser-evaporator parts 33, 43 and absorbed in the expeller-absorber parts 32, 42. Will the heat transformer 41 is used for air conditioning, the evaporation heat is generated by the Cooling circuit 23 taken from the room air RL. The one in the expeller-absorber part 42 resulting heat of absorption is depending on requirements and temperature conditions either released with the exchanger system 24 to the outside air L, or it is stored in the container 10 and thus serves, for. B. the evaporation of the condensate in the condenser-evaporator part 33 of the heat transformer 31. The evaporation in the Condenser-evaporator part33 can depending on availability and temperature conditions with solar heat, with the stored in the container 10 and thus z. B. from the exhaust air recovered heat or with the inherent heat of the absorption from the expeller-absorber part 32 can be made. In the latter case, the heat from this Part 32 with the exchanger system 25 is fed to the condenser-evaporator part 33. The heat of absorption released in the expeller absorber part 32 is transferred to the exchanger 26 of the building heating H or the domestic hot water preparation W supplied. in the In summer, the heat transformer 31 is used for hot water preparation and the heat transformer 41 the air conditioning. In the transition period, the heat transformer 31 warms up additionally the building heating H and the heat transformer 41 are either not needed or it is used to recover the heat from the exhaust air. In winter the two will Heat transformers 31 and 41 connected in parallel and both used for heating, as shown in FIG. In this case, the in the expeller absorber part 42 Released heat of reaction with the exchanger 27 of the building heating H and the Domestic hot water treatment W supplied. The heat source of the evaporation of the The condensate is identical in the two condenser-evaporator parts 33, 43.

With regard to the heat balance and the efficiency of the multi-stage heat pump arrangement, reference is made to the log p - l / T diagrams. Initially, the exchange phase is initiated by removing the stored heat from the first heat transformer. As already described for the single-stage system, the liquid methylamine is evaporated at 370 C and the chemical reaction is carried out in the opposite direction at 5.4 bar. The heat of evaporation is covered by the absorption process. The remainder of the heat released at 58 C is then 157.5 kcal / kg and is used to drive out one molecule of methylamine from the compound LiGl.3CH3NH2 (working fluid B) of the heat transformer 31. The expelled methylamine condenses again at 100 C. The heat of condensation is again given off to the outside air at 5 ° C. The condensation pressure of the methylamine of 2 bar prevails in the heat transformer 31 during the exchange phase. The expulsion is carried out at 530 ° C. The combined absorption / expulsion process of the exchange phase is shown in FIG. Since methylamine is released during the expulsion of both working fluids A and B, the voltage curve A1 is identical to the voltage curve B1. In this phase, an intermediate heat carrier circulates between the two working media A and B. The available temperature difference from OC is sufficient for the heat transfer. The molecular weight of the working medium B is 134. The weight loss of the substance B is therefore: gB = 31/134 = 23.1 t The corresponding reversible chemical reaction is: To expel 1 molecule of methylamine from substance B qB = 84.1 kcal / kg of heat is required.

d The weight ratio of the quantities of the two substances A and B involved in the heat exchange results from the ratio of the quantities of heat exchanged: from B to A As a result of the condensation of the expelled methylamine, the following amount of heat is given off to the environment in this phase: which corresponds to 36 t.

In the heating phase, the methylamine, which has evaporated at 370 ° C. under 5.4 bar, is reabsorbed at 76 ° C. Since the evaporation heat of the methylamine has to be covered by the absorption process, the following amount of heat is available: which corresponds to 29% of the originally stored solar heat. With this heat, heating and domestic hot water can be heated to around 710 and used to cover household heating requirements under the usual conditions and with the usual equipment. The absorption process of the heating phase is shown in FIG.

Reference is made to FIG. 9 for an illustration of the heat flow.

In this figure, X1 means the storage phase, X2 the exchange phase and X3 the release of heat from the second heat transformer 31 for heating purposes or for hot water preparation. It should be noted that the stated overall efficiency of 29% means the minimum possible exploitation of solar energy. An improvement the efficiency is possible by the evaporation of the methylamine in the exchange or in the heating phase also takes place with solar heat. The methylamine evaporation in the heating phase is z. B. possible if the three phases of Energy storage and release extend over two days, but two days for that identical, multi-stage heat pump systems are necessary.

1st system 2nd system night ----- exchange phase 1st day sunshine storage phase heating phase night exchange phase 2nd day sunshine heating phase storage phase night »exchange phase As can be seen, the continuous heat supply requires that the two identical systems work with a phase shift. Since the methylamine evaporation heat does not need to be withdrawn from the absorption process, the usable amount of heat increases by the same amount. Viewed differently, the additional solar heat collected at a lower temperature is immediately converted into usable heat, ie transformed to a higher temperature. In this case, the maximum value of the overall efficiency is: = (242 - 84.5 - 87.2 + 87.5) / (242 + 87.2) = 47.8 Oa The following is assumed: cv The minimum temperature of the heat transfer medium coming from the solar collector at which the accumulated heat is stored is still possible, is shown in Fig. 10 as a function of the outside temperature. The associated pressure in the corresponding heat transformer is plotted as a parameter. For the heat transfer and for the existence of an acceptable reaction rate, the temperature of the heat carrier must be above the minimum, ie above the equilibrium temperature. In FIG. 10, T denotes the storage temperature, 5 T denotes the outside temperature and Y denotes the working range.

a. The line of the chemical equilibrium state is analogous in FIG. 11 drawn for the release of the stored heat in the heating phase. The chemical The reaction takes place when the heat is dissipated, otherwise it comes self-regulating to a standstill. The dissipation of heat and ensuring a sufficient reaction speed cause sufficient hypothermia of the absorbate. The actual temperature level Tw the useful heat, d. H. that which can be effectively achieved with the heating or domestic hot water Temperature is indicated as working range Y in FIG. 11. As the abscissa is the necessary absorbate evaporation temperature T is selected.

v Whether the heat for the methylamine evaporation from the molten salt heat storage, taken from the solar collector or from the absorption process, depending on the current offer to be decided.

In summary, it can be stated that the heat pump arrangement described as solar heat storage and heat transformer in addition to an ordinary one Oil heating to save energy without changing the radiators or other heat distribution devices and can be implemented without any loss of comfort. So much for the warmth of the sun about 40 - 50 C can be collected with commercially available collectors, it can with 29 - 48 t efficiency transformed to 70 - 750 C with the heat pump arrangement and be used. After the stored solar energy has been consumed, the oil heating must take action. If the heat pump arrangement is additionally equipped with electric night power heated, the complete replacement of the oil heating is possible. If and when The replacement of the oil heating system depends on the development of the price for heating oil and night power.

A little more than Y3 of the solar heat collected goes per transformation stage lost. In the summer the single-stage is sufficient for domestic hot water preparation Transformation off. In this case the transformation losses are corresponding lower.

When assessing the transformation losses need the solar collector and the heat pump assembly can be viewed as a unit. Will the heat used directly without a heat transformer, there are no transformation losses, this requires a higher temperature in the solar collectors. Thus can less heat can be collected. The advantage of heat transformation is first Line in it to be seen that they are collecting more heat at lower temperatures permitted. The prerequisite for the heat transformation is less the absolute Temperature of the collected solar heat than the presence of a sufficient Temperature gradient to the environment.

With regard to the structural design and the routing of the cables a single heat transformer is now referred to Fig.

12-16.

The floor plan of the heat transformer designed as a storage unit 50 is designed in a square shape, so that several storage units can be used directly can be placed side by side in a row. In the storage unit 50 a cylindrical pressure vessel 51 is housed. In the corners of the square Unit 50, four molten salt latent stores 52 are arranged. These are pressureless Steel tanks that have the shape of a right triangle in cross-section and are slightly concave and the same height as the pressure vessel 51. Inside every latent storage A finned tube 53 runs over the entire length of the same. The heating water in the finned tube 53 flows through all four latent storages 52 in series. The ribs improve the heat transfer between the salt and the heating water. The pressure vessel 51 is in an absorbate container 54 (condenser-evaporator part) and an absorber container 55 (expeller-absorber part) divided. The two containers 54, 55 are thermally insulated 56 from one another. Normally the same pressure prevails in the two containers 54, 55, but there are also applications possible, at which the pressure can be different, which is why the partition 57 is designed as a pressure vessel bottom.

In the absorber container 55 there are fourteen heat exchange absorber plates at regular intervals 58 arranged. Training one of the lower plates is in 14 and 15 shown. The plates 58 are of three heating water supply and Support tubes 59, 60, 61 penetrated, which are offset from one another by 1200 are. On the plates 58 pipe coils 63 are welded, in which the heating water can flow over from one support tube 59, 60, 61 to the other. The circuit the flow through can be seen from FIG.

The heating water flows into the bottom five plates from inlet E. through the pipe 59 into the pipe 60 over. At the height of the space between the fifth and sixth plates is the tube 59 through a blind flange 62 interrupted. The heating water flows from the pipe from the sixth to the tenth plate 60 back into the tube 59. Above the tenth plate, the tube 60 is through a further blind flange 64 interrupted. On the top four heat exchanger absorber plates the pipe coil 63 is arranged offset by 1200, so that the heating water here flows over from pipe 59 to pipe 61. The pipe 61 leads to outlet A.

The three tubes 59, 60, 61 are through above the top plate a straight pipe piece 65 connected to one another. A flowing over of the water from pipe 59 through pipe 65 into pipe 61 is prevented by the blind flange 66. in the Inside the tube 60, a thinner coaxial tube can be arranged which is guided from below to the pipe section 65. This thin pipe penetrates the blind flange 64 and is used to vent the heat exchanger through the vent valve 67.

Between the tubes 59 and 60, the plates 58 are folded at the edge, these edges 68 touching one another, so that over the entire height of the heat exchanger an uninterrupted flat surface is created. After welding the heat exchanger bundle together A close-meshed wire mesh 69 is placed around the plates on the tubes 59, 60, 61 and attached to the surface created by the folding by spot welding.

Before the wire mesh 69 is closed in the middle of the surface, the gaps between the absorber plates with the granular working medium filled up. After the wire mesh 69 is closed, the absorber container 55 becomes placed in the pressure vessel 51, the insulation 56 placed on top and the intermediate floor 57 welded in.

Located in the upper part of the pressure vessel 51, in the absorbate container 54 three condensation evaporator plates 70 different training, which also of heating water are flowed through. The circuit of the flow can be seen again from FIG. Through the coil 75 of the top plate the heating water flows from pipe 72 to pipe 73. Between the upper and middle The tube 72 is interrupted by a blind flange 76 so that the water flows back in the pipe coil of the middle plate from pipe 73 to pipe 72. The bottom plate is rotated by 1200 in relation to the middle plate, so that the heating water thereby flows from pipe 72 to pipe 74 and thus to outlet A.

After completion, the pressure cylinder 51 is evacuated and with Filled absorbate gas. After the heat storage, in the state charged by heat, the condensed absorbate fills the absorbate container 54 to almost the level of the top one Plates.

To the absorbate container and the upper part of the absorber container. lines 77, 78 and 79 are connected. A pressure measuring element is attached to the line 72 and a pressure relief valve connected, the latter in the event of overheating of the absorbate gas this leads into the open. Between lines 77 and 78 is a Level meter attached, which shows the level of the condensed in the absorbate tank 54 shows the absorbates and thus the charge status of the memory Gives information. The absorbate gas can be between the connections of the lines 77 and 79 circulate freely.

The required storage capacity is achieved by connecting several Storage units applied, these are installed at the same level. The lines 77, 78 and 79 then serve as connecting lines through which the Absorbate can circulate freely. In this arrangement with several storage units there is only one safety valve and one pressure and level measuring element needed.

An application of the invention will now be described with reference to FIG. in which two single-stage heat pump arrangements 80 ', 80 "are coupled to one another in this way are that alternatively the one arrangement in the storage phase and the other arrangement works in the heating phase. Two heat transformers 81 ', 81 "with the associated integrated latent storage 82 ', 82 "form the double system, their circuit and Operating conditions will now be explained.

The charging or recharging of the heat transformers 81 ', 82 "with Heat from night electricity as well as the direct heating of the domestic hot water in the boiler 83 takes place with the heating water as an intermediate heat carrier, with the water in the water heater 84 is heated. The solar collector 85 must be equipped with a heating water / outside air heat exchanger 86 can be added. With this heat exchanger 86, the condensation heat of the absorbate at the storage of solar heat is released to the outside air L. With advantage will the heat exchanger 86 is designed and installed to allow heat recovery from the exhaust air in the heating phase.

There are a total of four heating water circulation pumps in the system: a common heating pump 87, a common collector circulation pump 89 and each a circulation pump 88 ', 88 "for the two heat transformers 81' and 81". To the three-way heating control valve 91 are two bypass three-way control valves 90 ', 90 "for regulating the vaporization of absorbate and with it the pressure.

All other valves 92-105 are three-way solenoid valves of the simplest Execution. They control the heating water flow and thus set the operating status fixed. In addition, a non-return valve 106 is used.

The operation of the double system varies with the outside temperature, must be adapted to the supply of solar energy and follows the day / night cycle: a) Daytime operation in summer This operating mode is operated when the offer is on Solar energy is large and heating can be dispensed with. The collected solar heat is only required for domestic hot water treatment. Works accordingly one of the two systems (e.g. system 80 ') in the storage phase and the other in the heating phase. The circulation pump 89 conveys the water via the valve 104 to Solar collector 85, then via the valves 96 ', 103, 102, 101 to the expeller absorber, where the absorbate is expelled with the heat of the sun and finally via the Valve 97 'back to the suction side of the pump.

If the temperature in the collector is temporarily not available for expulsion is sufficient, the expeller absorber is bypassed via the valves 101 and 105. the Circulation pump 88 'presses the water through valves 92' and 93 'to the heat exchanger 86, then via the control valve 90 to the absorbate container. With this circulation is the Release of the absorbate condensation heat to the outside air is guaranteed.

b) Night operation in summer The domestic hot water boiler 83 is mainly charged at night, but can also be recharged at any time during the day.

However, the solar energy is stored during recharging interrupted in system 80 '. The circulation pump 89 conveys the water through the valve 104 via the (switched off) water heater 84 and the valve 102 to the hot water boiler 83. The cooled water reaches the expeller absorber via valve 100 81 ", where it is heated before it is returned to the pump 89 via the valves 97'1 and 105 will.

In this case, the heat of vaporization of the absorbate is also generated by the heated, Covered water emerging from the expeller absorber. Through the valves 97 '', 98, 90 ", the circulation pump 88" and finally through the valves 92 ", 100 that will Water returned to the expeller absorber 81 ″. The reaction pressure becomes regulated by the three-way bypass control valve 90 ".

c) Daytime operation in the transition period In this operating mode, the solar heat is used for heating in addition to heating the hot water boiler. The two systems 80 'and 80 "work alternately like in summer operation.

System 80 'is e.g. B. charged, same as described under a). System 80 "can also do exactly the same and with first priority to the Charging the hot water boiler 83 are needed. The heating water is used in the heating drive circulated with the pump 87 through the radiators. The room temperature regulation leaves the three-way control valve 91 in the direction of the valve if the temperature is too low 100 of the expeller absorber 81 "open.

The water heated in the expeller absorber then flows through the valves 97 "and 105 back into the heating water circuit.

The absorbate evaporation is advantageously carried out with solar heat. The pump 88 "pushes the water through the valves 92", 93 "and 94" to the solar collector 85. From here, the heated water passes through valve 96 ″ to the bypass control valve 90 "and thus to the absorbate container. The absorbate evaporation in system 80" and the Absorbate expulsion or storage in the system 80 'are carried out simultaneously with solar heat performed.

If there is too little solar heat, the heating is switched on with the system 80 "continued by removing the absorbate evaporation in the same way from the absorption is covered, as described under b) when reloading the hot water boiler has been. As long as heat has been loaded into the molten salt latent storage (see next Section: Night operation in the transition period), this heat is given priority used for absorbate evaporation.

d) Night operation in the transition period On days with little sunshine this will be System working in the storage phase is not fully charged. Depending on the heating requirement is recharging with heat from electric current during the subsequent one Night necessary. When reloading, the water with the circulation pump 89 through the Valve 104 passed to the water heater 84, where it is heated. Afterward it flows through the valves 102 and 101 to the expeller absorber (e.g. of the system 80 '), where the remaining expulsion takes place, and from here via valve 97' back to pump 89. During the expulsion with electric night energy can the heat of condensation of the absorbate is either stored in the molten salt reservoir or used directly for heating. In the first case, the water is from the pump 88 'via the valves 92', 93 ', 94' and 95 'to the latent storage 82', from where it goes to the bypass control valve 90 'and thus to the absorbate container. With the same Cycle, the heat is taken from the molten salt storage tank and used to vaporize the absorbate used. The valve is bypassed while the molten salt storage tank is charging 90 'closed. During the evaporation of the absorbate, the valve 90 'also regulates this Fall the operating pressure. The absorbate condensation heat is used directly for heating is used, the water is from the pump 88 'over the valves 92 ', 93', 94 'and 95' to the heating three-way control valve 91 and thus to the radiator circuit guided.

From here it arrives via the non-return flap 106, the valve 98 and the bypass control valve 90 'back to the absorbate container.

The hot water boiler 83 is charged or recharged with the pump 89, which transfers the water via the valve 104 to the water heater 84 and via the valve I02 to the boiler 83, from where it is via the valve 103 to The suction side of the pump. This charging process is an alternative to charging of the heat transformer.

e) Night operation in winter As far as solar heat can be collected, the heat pump arrangement is the same in winter as in the transition period, and operated as described under points c) and d). In the coldest season the solar energy cannot cover the heat demand by far. The expulsion will therefore take place mainly or entirely at night with electrical energy.

The two storage systems 80 ', 80 "are for charging in series switched. The pump 89 presses the water through the valve 104 to the water heater 84. From here it arrives via the Valves 102 and 101 to the expeller absorber 81 ', then via the valves 97' and 99 to the absorber 81 "and finally via the Valve 97 ″ back to pump 89. The heat of condensation of the expelled absorbate can either be used directly for heating, or it is stored in the molten salt storage tank loaded as described under d).

f) Daytime operation in winter The two of them are at the coldest time of the year Storage systems connected in series. The water passes from the heating control valve 81 via valve 100 to expeller absorber 81 ', then via valves 97' and 99 to Expeller absorber 81 "and finally via the valves 97" and 105 back to the Radiator circuit H. The circulation is brought about by the heating pump 87. Since the useful temperature of the heating water is reached in the expeller absorber 81 ", the absorbate evaporation of this system takes place with heat from the latent storage 82 ", as described under point d). In system 80 ', a slightly lower Pressure prevail, so that here the heat from the exhaust air is used to evaporate the absorbate can be. The water cycle is exactly the same as with the release of the condensation heat to the outside air according to point a), only the heat flow is the other way around, and the air / water heat exchanger 86 is flowed against by the building exhaust air. As long as a little solar heat is still available, it can be used to vaporize the absorbate can be used in the system 80 '.

In summary, the following will refer to the advantages of the above-described Invention pointed out: - In the heat pump arrangement acting as a memory the energy during heat extraction both in the chemically bound form and also available as heat The bound energy is released in a self-regulating manner, according to the demand or the amount of heat dissipated. The temperature level of the Heat release corresponds to the normal heating or domestic hot water temperature of the household; also the solar energy collected and stored at lower temperatures can be transformed to the required temperature level with a reasonable degree of efficiency will.

- A charged heat transformer can be chemically bound Heat for any length of time in a cold state, d. H. on Ambient temperature, save. During the release of the heat corresponds to the Storage temperature of the normal hot water boiler temperature. Accordingly, are the insulation costs and the heat losses are low.

The storage with heat-transforming properties is claimed approximately Y4 of the volume and Y3 of the weight of a conventional hot water storage tank for solar heat, assuming a temperature spread of the water of 170 C.

This results in considerable volume savings.

In relation to the costs, the values of the storage mass, the container and isolation. The insulation cost of the heat transformer correspond to the costs of a hot water boiler of the same size. With that they are up related to the stored amount of energy, considerably lower.

Because the insulation is only effective during the replacement or heating phase is, the heat losses are correspondingly low on average. During the release of the stored heat, there is a pressure in the heat transformer that is equal to that The pressure of a hot water storage tank is around 1500 C storage temperature. To note is also that in the event of a break or leak, only one Small part of the non-toxic and difficult to perceive absorbate gas escape can. However, the stored energy is not released, such as. B. with the hot water boiler in a similar incident. The consequences are correspondingly milder. the Chemical storage mass costs are only a fraction of the container costs.

No external energy is used for the functioning of the heat pump arrangement alone needed. Like any solar thermal heating system, however, the heat pump arrangement must be suitable for bridging longer periods of bad weather to ensure uniformity Comfort can be supplemented by heating from another energy source. this happens particularly simply by installing the electric heater in the storage tank. So the heat pump arrangement works like an ordinary one in bad weather Night storage heating.

Compared to supplementing a solar energy heating system with a conventional heat pumps without storage have the advantage of consuming night-time electricity.

In the long term, energy policy aspects also play a role, because in the future a significant part of the electrical energy will be generated by nuclear power plants is delivered.

It is known that nuclear power plants should advantageously run base loads. In off-peak periods, the excess energy can be used for pumping in pumped storage plants be used.

The way in which the nuclear power plants operate also contributes to the nighttime power supply is cheaper than daily or peak electricity. With an increasing proportion of nuclear power plants this is even more pronounced in the energy supply.

The possibility of building central energy storage, d. H.

Pump storage plants are geographically limited and require large ones Investments. The stored energy is released to cover peak demand, so that the uneven load on the distribution network remains.

Decentralized storage of the energy would be cheaper because it would the uniform loading of the distribution systems could also be achieved.

Household and trade almost need in industrialized countries today half of the primary energy available.

More than two thirds of this is used for space heating and domestic hot water treatment used. For this purpose, heat that is not of very high quality is sufficient: direct heat The use of high-quality electrical daily energy does not make sense. Heat pumps "multiply" the electrical ones Daily energy through transformation the ambient heat, however, there is the possibility of collecting this ambient heat associated with difficulties. This means that the actual heat source is missing. We see from the ambient air as a heat source due to the risk of freezing, then the only one Heat source accessible everywhere at the point of consumption the solar radiation. Her However, direct use is due to the meteorological fluctuations and the associated associated, uneven availability without solving the short- and medium-term Storage limited.

The combined use of cheap night electricity and solar energy to cover the household heat demand is now through the present invention guaranteed.

This makes it a real alternative to heating oil. The one to be expected The contribution of solar energy to the energy supply is estimated at around 2 - 5 t. With the use of the heat pump arrangement, this value can increase considerably.

The essential importance of short and medium term energy storage lies in the fact that with their help, energy supply, distribution and consumption are related to each other can be matched. This opens up a greater technological scope, that for more economical extraction, distribution and combined Use of electrical and solar energy can lead.

The main energy policy advantages of the heat pump arrangement for The combined use of solar energy and night-time electricity are: - considerable Improved comfort and thus the possibility of better dissemination of solar energy heating; - better utilization of power generation and distribution facilities; - increased security of supply and increased independence from oil; - Eliminate the rivalry of solar energy and nuclear energy from the energy policy discussion, since these two Now ideally complement energy sources; - because heating and hot water consumption are predominant are covered by the oil and account for around 50 - 60% of the total energy consumption, the advantages of the heat pump arrangement described are obvious.

Claims (15)

Claims 1. Method for periodic storage and release of heat using at least one heat transformer with one therein included working medium, which is produced by an endothermic, reversible reaction in a gaseous and a solid component can be converted, characterized in that that in a storage phase that in the expeller absorber part of the heat transformer housed working fluid heat is supplied to release the gaseous Component flowing into the condenser-evaporator section of the heat transformer, where it is condensed with release of heat, and that in a storage phase Condensate is evaporated in the condenser-evaporator part and releasing heat of reaction is bound again to the solid component in the expeller-absorber part. 2. The method according to claim 1, characterized in that in the Storage phase solar heat and / or electrically generated heat is supplied, and that the heat to be dissipated during the condensation to the environment and / or to a Latent heat storage is released. 3. The method according to claim 1, characterized in that the in the heat of reaction released during the storage phase to a domestic water heating system and / or to a space heating system. 4. The method according to claim 1, characterized in that the in the heat supplied to the storage phase has a lower temperature than that at the heat released for storage. 5. The method according to claim 1, characterized in that the gaseous Component of the working medium is methylamine or ethylamine. 6. The method according to claim 1, characterized in that the solid Component of the working medium calcium and / or lithium and / or magnesium chloride is. 7. The method according to claim 1, characterized in that at least two heat transformers are coupled to form a multi-stage heat pump unit, and that the heat released during the depletion from the first heat transformer at least partially in the second heat transformer cached and is then released at a higher temperature level. 8. The method according to claim 7, characterized in that at one a heat pump unit consisting of at least three heat transformers the heat released during the storage is fed to the third heat transformer and that this heat is also temporarily stored and at a higher temperature level is released, the third heat transformer alternatively for heating purposes or operated as an absorption chiller for air conditioning. 9. The method according to claim 1. or claim 7 or claim 8, characterized characterized in that the single or multi-stage heat pump unit together with a another, identical unit is operated, and that alternately the heat in stored in one unit and released in the other unit. 10. Heat pump arrangement for performing the method according to claim 1, characterized by at least one self-contained heat transformer (1, 31, 41, 50, 81 ', 81 "), consisting of an expeller-absorber part (2, 32, 42, 55) and a condenser-evaporator part connected to this (3, 33, 43, 54), with the working fluid housed in the heat transformer without loss is. 11. Heat pump arrangement according to claim 10, characterized in that that the heat transformer (50) and a latent heat storage (52) to a storage unit are summarized. 12. Heat pump arrangement according to claim 11, characterized in that that the cylindrical heat transformer (50) housed in a cuboid housing is, in the corners of which consists of four parts latent heat storage (52) is arranged is. 13. Heat pump arrangement according to claim 10, characterized in that that several heat transformers (1, 31, 41) to a multi-stage heat pump unit are summarized. 14. Heat pump arrangement according to claim 10 or claim 13, characterized characterized in that, in addition to a single or multi-stage heat pump unit, a further, identical one-unit is provided, the units in such a way with one another coupled are that alternately one unit for storing heat and the other Unit is operated to remove heat. 15. Heat pump arrangement according to claim 11 or claim 12, characterized characterized in that the latent heat storage (52) is water or a heat supply Contains fusible salt.