METHOD AND ARRANGEMENT FOR PRODUCING COOLING POWER

Abstract: The invention relates to a method and an arrangement for producing cooling power for one or more buildings and for distributing the power to the buildings by means of liquid circulating in a pipe system, the cooling power being produced by an absorption aggregate (5, 8, 9, 10) or some other aggregate that produces heat to be condensed, and the cooling power being transferred to the supply air of the buildings by an air-conditioning unit or the like. To lower the investment costs, at least part of the return water coming from the air-conditioning unit or the like is arranged to be conducted to the absorption aggregate (5, 8, 9, 10) or some other aggregate that produces heat to be condensed, where it absorbs the condensation heat generated in the aggregate.

Description: Method and arrangement for producing cooling power The invention relates to a method for producing cooling power for one or more buildings and for distributing the power to the buildings by means of liquid circulating in a pipe system, the cooling power being produced by an absorption aggregate or some other aggregate that produces heat to be condensed, and the cooling power being transferred to the supply air of the buildings by an air-conditioning unit or some other apparatus that consumes cooling energy. The invention also relates to an arrangement for producing cooling power for one or more buildings. Today buildings are generally cooled by a cooling aggregate based on a compressor aggregate, the cooling aggregates being dispersed to places of use. Cooling power is produced in them by electricity. The proportion of the cooling of buildings in the consumption of electricity is now fairly important, e.g. in the Southern European countries the electricity consumption peaks in the summer. With regard to production, the consumption also occurs at an unfavourable time. The heat inevitably generated in connection with production of electricity cannot be used for much else than production of hot tap water, and so it has to be condensed and supplied to waterways e.g. by brine condensers or to air by cooling towers. Cooling power could also be produced by waste heat produced in the production of electricity in so- called absorption aggregates, the best known of which are lithiumbromide/water and ammonia/water aggregates. The consumption of electricity and thus e.g. emissions of C0 2 could be reduced with these aggregates, and the waste heat, which is now completely wasted, could be utilized. The preferred way of generating chill is a so- called district cooling system, in which cooling power is generated concentratedly in power plants and supplied to users via a pipe system in the same way as district heat. This has an advantageous effect e.g. on servicing costs, which in the present, dispersed systems are high, and on reliability, on levelling down of random load peaks, etc. District cooling systems have not become common, however, due to high investment costs. Although the kWh price of the chill generated in this way is low as compared with the price of electricity, the number of hours of use is so small in those climatic zones where district heating systems are worth building that the investment costs will not be covered. In Finland, for example, such systems have thus not been built. The majority of them exist in Japan, Korea and the U.S.A. Finnish Patent Application 940,342 teaches a 3-pipe system by which the costs of the distribution system can be reduced significantly. In addition, Finnish Patent Application 940,343 teaches a system in which the operations of the heat exchangers are combined, which makes it possible to significantly reduce the investment costs in individual buildings. Further, Finnish Patent Application 940,344 teaches a system in which the return water of the district heating/cooling system is used as condensation water, which is needed by the absorption aggregate, whereby no cooling tower or other condenser is needed in the power plant. This reduces the investment costs and the costs of use in the production of district chill. The above measures make district cooling systems worth building in new communities where all buildings that require cooling are connected to the system. The proportion of such building, however, is small in industrialized countries, and its proportion in all building is growing smaller. Most building now comprises extension or renovation of existing communities. It is then not possible to connect a significant number of buildings simultaneously to a district cooling system when a system is built in the area. A small number of buildings connected is not sufficient to cover the investment costs of a district cooling system and of generation of district chill, which prevents building of district cooling systems in existing communities. A similar problem has been encountered when district heating systems have been built. The problem has been solved by movable heating stations in which heat has been produced only for a limited area, whereby the costs of a distribution system have remained small and can have been covered immediately. When a sufficient number of areas has been connected, a main network is built, and the areas are connected to the power plant via the network. The movable heating stations are shifted to new areas or maintained in the area as heating stations that are used during maximum heat demand. The idea cannot be applied to building a district cooling system without difficulty. It is true that the costs of building a main network are eliminated, but the use of return water as condensation water is here not possible. Because of this, cooling towers, ground water, etc. should be used. But, for example, it is often impossible to place cooling towers in urban areas for architectural reasons, lack of space, etc. Some plants of the above type based on absorption aggregates have been built, and technically such systems work well, but their competitiveness with compressor cooling is questionable, and the smaller the number of hours of use (i.e. in mild and cold climatic zones, where district heating systems are common), the less competitive they are. The reason for this is that the investment costs of an absorption heat pump, a cooling tower and a distribution network are much higher than the costs of a corresponding compressor aggregate. Even when the energy, i.e. heat, is almost free and the electricity used by the compressor aggregate is expensive, a reduction in the costs of use is not sufficient to cover the difference in the investment costs if the number of hours of use is not sufficiently great. The situation is made worse by a strong, short-term load peak in the cooling demand, the peak being more than double the average load during a cooling period. This is due to the fact that in the mild and cold zone, the design outdoor temperature prevails only in the afternoon on a few days a year. The average cooling load is also short-term. Cooling, unlike heating, is not needed round-the-clock but only at midday and in the afternoon. Since the consumption of electricity in the countries situated in the cold and mild zones peaks in the winter, high investment costs cannot be substantiated by a reduction in the investments on electricity production machinery, like in the countries situated in the hot zone. Only a few such plants have thus been built in Middle and Northern Europe for test and research purposes, although they are common in the hot zone. The above system is described e.g. in simultaneously filed Finnish Patent Application 954,949. The document also discloses a system in which investment costs can be essentially reduced and reliability of the plant can be improved as compared with the prior art. These advantages are achieved by cutting the peak load by evaporative cooling arranged in the air-conditioning units of a building and by levelling daily variation in consumption by providing the system with a tank from which power that has been loaded at night or some other time when there is no consumption or consumption is minimal is unloaded in day-time during a consumption peak. The evaporative cooling and especially the tank naturally cause additional costs, which, however, are much smaller than the savings achieved by making the absorption heat pump, spray tower, pipe system, etc. smaller. They do, however, impair the competitiveness of the system as compared with compressor cooling. In the system described in the above-mentioned Finnish patent application, the use of electricity is compensated for in the summer by the use of waste heat, which is otherwise almost totally wasted in the summer, and the system levels the use of waste heat over a 24- hour period. This makes production of energy more economic. Investments on the district heating network and production of heat, however, are determined by the amount of heat consumed in the winter. The investments on the production and distribution of heat are determined by peak consumption, which is primarily dependent on the outdoor temperature. The design outdoor temperature, however, prevails relatively seldom. The design temperature of Helsinki, for example, is -26°C. This temperature, however, prevails on the average during fewer than 18 hours per year. A temperature of or below 20°C, in turn, prevails on the average during about 88 hours, whereas the entire heating period is about 5000 to 6500 hours in length, depending on the building. The situation is thus very similar to the summer. The temperature duration curve comprises a high peak value of short duration. With regard to production and distribution of heat, the situation is worsened by variation in the consumption in a 24-hour period. About half of the buildings are not used except during the working hours. In such buildings, ventilation is usually stopped or adjusted to be minimal in the night and the weekends. The proportion of ventilation in the heat consumption of an average building is about half, but in these buildings the heat consumption in a 24-hour period varies continuously between 50% and 100%. This further increases the difference between the average and peak consumption of heat. The indoor temperature of a building like this is also often lowered when the building is not in use, which worsens the situation even further. In recent years, it has been noticed that the energy saving measures taken have made the situation even worse. The yearly consumption of heat has dropped drastically during the last 20 years. The peak consumption, instead, has not dropped nearly as much. There are several reasons for this. Maybe the most important reason is that heat cannot be recovered from exhaust air at full capacity during the peak load because of the risk of freezing. Another major reason is that the indoor temperature is lowered when the buildings are not in use. With regard to production and distribution of heat, the situation is difficult. A heat power plant and a distribution system should be designed in accordance with peak consumption, but their average degree of use would then be about 25% to 35%. In addition, the situation is growing worse and worse. In practice, the power plant and distribution system, which are expensive to build, are not designed in view of the peak load but of a much smaller output. The peak output of heat consumption is generated in heating stations used during maximum heating demand, the heating stations being arranged in different parts of the distribution system and their proportion of the overall heating power optionally being large. In Helsinki, for example, the degree of use of the maximum heating stations is low, at best only a few dozen hours a year. The unit price of heat generated in them is very high because of the high investment costs . With an arrangement described in simultaneously filed Finnish Patent Application 954,950, the daily variation in heat consumption can be levelled such that the buildings connected to the system do not take any heat from the district heating network and in some cases may even be able to supply power to the district heating network when consumption in the other buildings is maximal. Correspondingly, they draw power from the network when consumption in the other buildings is small. The basis of the system is that a tank for storing cooling power is used even for the storage of heating power at a temperature that is higher than the temperature of the heat consuming apparatuses of the building. The system makes it possible to level peak loads caused by the other buildings and to make uneconomic maximum heating stations smaller or even replace them. As stated above, district heat return water obtained from present networks cannot be used in removal of extra heat from an absorption aggregate. A conventional temperature for return water in a design situation is about 40-50°C. The temperature of the water to be condensed, as it returns from the absorber, is about 40-45°C, and it should be cooled to below 30°C, which is naturally impossible to accomplish with district heat return water. To condense extra heat, one thus needs cooling towers, closed air-cooled condensers, brine condensers or the like, which cause extra costs, consume electricity, bring about servicing costs, etc. A particular problem is the space they need, since extra space is very difficult to find in old buildings in a city centre. The other problems include e.g. architectural problems and health hazards, the latter relating to cooling towers and air-cooled condensers where the temperature is ideal e.g. to the bacterium legionella . The object of the invention is to provide a method and an arrangement by which the drawbacks of the prior art can be eliminated. The object is achieved by the invention. The method of the invention is characterized in that at least part of the return water coming from the air-conditioning unit or some other cooling energy consuming apparatus is conducted to the absorption aggregate or some other aggregate that generates heat to be condensed, where the water absorbs the condensation heat generated in the aggregate. The arrangement of the invention, in turn, is characterized in that at least part of the return water coming from the air-conditioning unit or some other cooling energy consuming apparatus is arranged to be conducted to an absorption aggregate or some other aggregate that generates heat to be condensed, where the water absorbs the condensation heat generated in the aggregate. The primary advantage of the invention is that either no condensers are needed at all in the system or their size and/or number can be significantly reduced from what it is in the previously known solutions. The drawbacks of the above prior art are either eliminated altogether or at least they become essentially more easy to overcome. In particular, the costs of the absorption aggregate are greatly reduced, which makes cooling energy produced by waste heat more competitive as compared with compressor cooling. The idea of the invention is that the apparatuses for generating, storing and consuming cooling power are integrated into a single unit that is used differently at different times of the day. The basic idea is that the temperature of the return water in an air-conditioning system that is often the sole or at least the most important user of cooling power is less than 20°C. It is thus particularly well-suited for use as condensation water in an absorption aggregate, and so the return water of the air-conditioning system is not supplied to a tank in the invention but the water is supplied to a condenser part of the absorption aggregate and from there to the tank at a temperature of about 45°C instead of 20°C. Let us assume that in most buildings in the mild zone, no cooling is needed at night, since the temperature of the outdoor air usually drops to ' at least 20°C, and most buildings do not have any internal heat loads at night. The air- conditioning units, for example, are thus usually turned off in the evening. In the system of the invention, the air-conditioning units that usually stand idle at night are used in day-time for removing the condensation heat stored at night. This makes it possible to decisively reduce the size/number of separate condensers, or to eliminate condensers altogether. In the following the invention will be described in greater detail with reference to the embodiments illustrated in the attached drawing, in which fig. 1 shows a general diagram of a first embodiment of an arrangement according to the invention, fig. 2 shows a general diagram of a second embodiment of an arrangement according to the invention, fig. 3 shows a general diagram of a third embodiment of an arrangement according to the invention, and fig. 4 shows a general diagram of a fourth embodiment of an arrangement according to the invention. Fig. 1 shows a first embodiment of the invention. Reference numbers 1-4 indicate a system of district heating pipes for supplying thermal energy to an absorption aggregate 5-12 that generates cooling power. Numbers 13-16 indicate a drain pipe system of the absorption aggregate, and numbers 26-29 indicate a tank and its pipe system. Apparatuses consuming cooling power are represented by an air-conditioning unit 18-25 to 35-39. A pipe system for transferring cooling water is indicated by reference numbers 32, 33. For the sake of clarity, all parts that do not help to understand the invention have been excluded. For example, usually dozens or even hundreds of air-conditioning units 18-25 and 35-39 and even other cooling energy consuming apparatuses are connected to the transfer pipe system 32, 33. The system of fig. 1 operates as described in the following. Hot water from a supply pipe 2 connected to a district heating network 1 is supplied through a control valve 7 to a boiler unit 5 of an absorption aggregate. In the boiler unit, the water heats a mixture of an absorbent and a refrigerant and returns, cooled, through a return pipe 4 of a pump 6 to a return pipe 3 of the district heating network. The refrigerant is evaporated from the absorbent in the boiler unit 5 of the absorption aggregate and conducted to a condenser part 8, where it is re-liquefied by cooling. The cooled liquid is conducted to an evaporator part 9 simultaneously reducing its pressure, whereby the liquid is evaporated and cooled. Cooling water circulating in a transfer pipe system 32, 33 is cooled with cold steam. The refrigerant is conducted from the evaporator 9 to an absorption part 10, to which is also conducted the absorbent reduced in the boiler 5. In the absorption part 10, the refrigerant is re-absorbed, whereby heat is released. The mixture is pumped with a pump 12 through a heat exchanger 11 back to the boiler 5. The heat released in the condenser part 8 and absorption part 10 of the absorption aggregate must be conducted away in order that the process would work. This has usually been done by supplying cooling water having a temperature of less than 30°C to the condenser part 8, where it absorbs the condensation heat of the refrigerant. The cooling water has then usually been conducted to the absorption part 10, where it absorbs the absorption heat and that part of the heat absorbed into the absorbent in the boiler 5 which cannot be transferred in heat exchanger 11. Subsequently, the heated cooling water has usually been conducted from the absorption part 10 to a condenser, which may be a cooling tower, brine condenser, closed air-cooled condenser, etc. The system of the invention employs water returning from the air-conditioning units 18-25 and 35-39 through return pipe 32 and having a temperature of about 20°C. When the system operates at full capacity, cooling power is supplied to the air- conditioning units both from a tank 26 and from the evaporator part 9 of the absorption aggregate through a pipe 33. For the sake of simplicity, let us assume that an equal amount of power is obtained from both. A control valve 14 then supplies equal flows of water to the evaporator part 9 for cooling and to the condenser part 8 for use as cooling water. The cooled water is supplied through pipe 33 to the air-conditioning unit 18-25 and 35-39. In addition, an equal flow of water is drawn from tank 26 through a pipe 28. From the condenser part 8, the water is supplied through pipe 16 to the absorption part 10 and further through pipe 14 to the tank 26. A valve 27 is in a position where the flow path to pipe 27 is closed. The flow of water flowing to and from the tank 26 are equal. The system is also thermodynamically in balance if the design values are selected e.g. such that the temperatures of the cooling water in the air- conditioning system are 10/20°C and those of the cooling water in the absorption aggregate are 20/45°C and the power factor is 0.7. Heat is supplied to the evaporator of the absorption aggregate in an amount that corresponds to the cooling power supplied to pipe 33, and to the boiler in an amount that is about 1.5-fold (produced power divided by power factor, i.e. 1/0.7) . The total amount of heat to be absorbed is then about 2.5-fold as compared with the amount of cooling power produced. This also corresponds to the ratio of temperature differences (45/20) / (20-10) = 2.5. It is fairly easy to balance the system with different flows of water by selecting the design temperatures appropriately. When cooling is no longer needed in the evening, valve 29 closes the flow path through pipe 38 to the evaporator part 9 and tank 26 and opens the flow path through pipe 27 to the tank 26. A supply air fan 38 of the air-conditioning unit is stopped, and the flow path to a supply air radiator 19 is closed by a control valve 25. In addition, flow path 36 for exhaust air is closed and flow path 37 for outdoor air is opened. A pump 24 further circulates water through a heat exchanger 23 and an exhaust air radiator 22. Pump 20 is still in operation. Since the flow path through pipe 28 to the tank 26 and to the evaporator part of the absorption aggregate is closed, the pump draws hot 45-degree water partly from the tank 26, partly through pipe 13 from the absorption part 10 of the absorption aggregate. The water is cooled in heat exchanger 23 to about 20°C and returned through pipe 32 to valve 14, which supplies half of the water flow to the evaporator part 9 for cooling and half to pipe 15 for use as condensation water in the absorption aggregate. Since valve 29 closes the flow path to pipe 33, the cooled water flows through pipe 28 to the tank 26, where cold water is thus stored for the next day. When the tank 26 is full, which can be checked by a thermostat arranged in the upper part of the tank or in pipe 27 or by some other way known per se, fan 39 and pumps 12, 20, 24 are stopped, and valve 29 and the closing means for air intakes 36 and 37 are set in a position corresponding to day-time use. As stated above, fig. 1 shows only the parts that help to clarify the invention. In reality, the overall system is much more complicated. For example, in addition to individual pumps 20 of air-conditioning units, there is usually a main pump in pipe 32 or 33; the condensation circuit 13-16 of the absorption aggregate is usually provided with a pump; to make the absorption and condenser part adjustable, an adjustment means similar to control valve 7 of the boiler part 5 is needed; etc. All these solutions in which art known per se is applied are naturally encompassed by the invention. Fig. 1 shows one example for utilizing heat exchanger 22 of an air-conditioning unit. Heat exchangers on the side of supply air can also be used. The exemplary solution of fig. 2 can be used, for example, when the heat delivery surface of heat exchanger 22 is not adequate to sufficiently cool the water flowing to exchanger 33. Heat exchanger 19 can then also be put to use by providing closable openings 39, 40 on the supply air side, air inlet 39 being open and outlet 40 - which leads out - being closed in day¬ time. At night, inlet 39 is closed and outlet 40 is open. Fan 38 will not be stopped and valve 25 is set in a position where the flow path to a bypass line 41 is closed and the flow paths to heat exchanger 19 are open. Liquid also flows through heat exchanger 19, which usually almost doubles the heat delivery surface. Figs. 1 and 2 show an air-conditioning unit in which heating, cooling and heat recovery are integrated into a single heat exchange circuit. Naturally, the principle of the invention can also be applied when the unit comprises separate heat exchangers for heating, cooling and/or heat recovery. The principle can be applied to any heat exchanger whatsoever of the air- conditioning unit, or even an auxiliary heat exchanger can be arranged in the unit or the openings 36-40, if the heat exchangers of the unit do not have sufficient capacity. All these embodiments, and the connection of the exchangers e.g. in parallel or in series in a manner known per se are encompassed by the invention. Figs. 1 and 2 show a heat exchanger 23 serving an individual air-conditioning unit. The heat exchangers of a plural number of air-conditioners in a zone or building can naturally be combined to form one large heat exchanger. Especially in small plants, heat exchanger 23 can also be eliminated altogether, and liquid can be supplied from pipe 33 directly to a flow circuit of the air-conditioning units. Figs. 1 and 2 show a single tank 26. It is often advantageous, for example with respect to the use of space, to use two or more smaller tanks, which can be connected in series or, for example, in parallel as groups intraconnected in series. Valves 35, 25, 29, 14 and 7 are shown as 3- way valves. It is naturally also possible to use 2-way valves. All solutions like this known per se are encompassed by the invention. The design temperatures and flow rates may sometimes have to be selected for various reasons in such a way that the system is not in thermodynamic balance. Temperature balance can be achieved, for example, by an arrangement shown in fig. 3, in which part of the liquid flowing in a pipe leading to the tank 26 is conducted by valve 42 to a condenser 43, which in fig. 3 is a spray tower. The condenser 43 may naturally be any apparatus known per se. The water is cooled in the condenser 43 and returned through pipe 44 by pump 47 to pipe 16. It is naturally also possible to draw water from pipe 16 and return it to pipe 15, draw it from pipe 13 and return to pipe 15. To achieve a balance in the flow rate, part of the liquid can be returned, for example, from pipe 16 directly to the tank. Fig. 4 shows an embodiment in which 45-degree water flowing in a pipe is used for pre-heating hot tap water. All or some of the liquid flowing in pipe 13 to the tank 26 is conducted by valve 42 to a tap water heat exchanger 45, in which water flowing in the tap water system 46 is heated. The embodiment is cheap and simple, and it makes it possible both to recover a reasonable amount of condensation heat and to reduce the amount of condensation energy exhausted. If the problems are the sufficiency of condensation water flowing in pipe 15 and/or the volume of the tank 26, heat exchanger 45 is preferably designed and/or valve 42 controlled such that the water temperature in pipe 47 is 20°C, i.e. the return water temperature of the air-conditioning system, and pipe 47 is connected to pipe 15 rather than to pipe 13. A pump must then naturally be provided in the flow circuit. The consumption of tap water varies greatly. If the aim is to recover as much energy as possible, heat exchanger 45 must have storage capacity. This can also be achieved by arranging a simple coil exchanger in the hot section of the tank 26. In some cases, an absorption aggregate will have to be used periodically e.g. in the spring or autumn when the cooling load of a building is light. Preferably, the problem is solved by using the aggregate only at night and storing cold water in a tank 26. In day-time, the absorption aggregate stands idle and cooling is effected by water stored in the tank. Air-conditioning units 18-25 and 35-41 need then not be used, either, since the water stored has a temperature of 20°C. It is also possible to provide an auxiliary tank for the 20°C return water of the cooling systems of the building produced between operating periods and/or for the 50 to 55°C water produced during an operating period, or for both. They are connected with pipe and control arrangements known per se, and the arrangements can be varied in many ways depending on the selected strategy of use. All the above solutions known per se are encompassed by the invention. As appears from the above examples, the basic idea of the invention can be implemented in various embodiments. The essential feature is that part or all of the condensation heat generated during the day is stored in the return water of an air-conditioning system or some other system that requires cooling power and is then released at night or some other time when no cooling is needed using a heat exchanger of the air- conditioning system. The above embodiments are not to be understood as limiting the invention, but the invention can be modified quite freely within the scope of the claims. It is thus obvious that the arrangement of the invention or details of the arrangement need not be exactly as described in the figures, but that other kinds of solutions are also possible. In the above description, cooling power is generated by an absorption aggregate, since the advantages are then greatest. Naturally, however, the invention can also be applied in other cooling power generating apparatuses that produce heat to be condensed.

Claims: Claims 1. A method for producing cooling power for one or more buildings and for distributing the power to the buildings by means of liquid circulating in a pipe system, the cooling power being produced by an absorption aggregate (5, 8, 9, 10) or some other aggregate that produces heat to be condensed, and the cooling power being transferred to the supply air of the buildings by an air-conditioning unit or some other apparatus that consumes cooling energy, c h a r a c ¬ t e r i z e d in that at least part of the return water coming from the air-conditioning unit or some other cooling energy consuming apparatus is conducted to the absorption aggregate (5, 8, 9, 10) or some other aggregate that generates heat to be condensed, where the water absorbs the condensation heat generated in the aggregate. 2. A method according to claim 1, c h a r a c t e r i z e d in that after the condensation part (8), the return water coming from the air-conditioning unit or some other cooling energy consuming apparatus is conducted to a tank (26) connected to the absorption aggregate (5, 8, 9, 10) or some other aggregate that generates heat to be condensed. 3. A method according to claim 1 or 2, c h a r a c t e r i z e d in that the water trans¬ ferring cooling power is cooled in the heat exchangers of an air-conditioning unit or the like when no cooling is needed in the air-conditioning system. 4. A method according to claim 2 or 3, c h a r a c t e r i z e d in that the power needed by the buildings is drawn during the day from the tank (26) in which cold water is stored at night. 5. A method according to claim 2, c h a r a c t e r i z e d in that the return water is conducted to the tank (26) through an absorption part (10) of the absorption aggregate (5, 8, 9, 10) or the like. 6. A method according to any one of the preceding claims, c h a r a c t e r i z e d in that after the condensation part (8) of the absorption aggregate or the like, at least part of the return water coming from the air-conditioning unit is conducted through a return water condenser (43) or heat exchanger (45) before it is conducted to the tank (26) . 7. An arrangement for producing cooling power for one or more buildings and for distributing the power to the buildings by means of liquid circulating in a pipe system, the cooling power being arranged to be produced by an absorption aggregate (5, 8, 9, 10) or some other aggregate that produces heat to be condensed, and the cooling power being arranged to be transferred to the supply air of the buildings by an air-conditioning unit or some other apparatus that consumes cooling energy, c h a r a c t e r i z e d in that at least part of the return water coming from the air-conditioning unit or some other cooling energy consuming apparatus is arranged to be conducted to the absorption aggregate (5, 8, 9, 10) or some other aggregate that generates heat to be condensed, where the water absorbs the condensation heat generated in the aggregate. 8. An arrangement according to claim 7, c h a r a c t e r i z e d in that after the condensation part (8), the return water coming from the air-conditioning unit or some other cooling energy consuming apparatus is arranged to be conducted to a tank (26) connected to the absorption aggregate (5, 8, 9, 10) or some other aggregate that generates heat to be condensed. 9. An arrangement according to claim 8, c h a r a c t e r i z e d in that the return water is arranged to be conducted to the tank (26) through an absorption part (10) of the absorption aggregate (5, 8, 9, 10) or the like. 10. An arrangement according to any one of preceding claims 7 to 9, c h a r a c t e r i z e d in that after the condensation part (8) of the absorption aggregate (5, 8, 9, 10) or the like, at least part of the return water coming from the air-conditioning unit is arranged to be conducted through a return water condenser (43) and/or heat exchanger (45) before it is conducted to the tank (26) . 11. An arrangement according to any one of preceding claims 7 to 10, c h a r a c t e r i z e d in that cold condensation water is arranged to be stored in the tank (26) at night, and that the tank (26) is arranged to supply the stored water in day-time to provide buildings with power.

Inventors: LESKINEN SEPPO, LESKINEN, SEPPO
Applicants: ABB INSTALLAATIOT OY, LESKINEN SEPPO, LESKINEN, SEPPO
Application year: 1996
Main classification: F24D11
IPC codes: F24F5, F25B29