AN AIR-CONDITIONING PLANT

Abstract: An air-conditioning plant for cooling the air in rooms of a single-family house comprises an evaporator (7), a compressor (8) and a main condenser (9) in a closed cooling circuit and a blower (10) capable of blowing air through the evaporator (7). The main condenser (9) is constituted by a substantially helical tube, the turns of which are place round a hot-water tank (11) in contact with the outer surface of said tank (11). The main condenser (9) and the hot-water tank (11) are made of the same type of material, whereby a secure transfer of heat from the main condenser (9) through the wall of the hot-water tank (11) to the water in the tank (11) is obtained. The lubricating oil of the compressor (8) is cooled by means of an oil-cooling condenser (18) in the form of a helical tube, the turns of which are placed round the hot-water tank (11) in contact with the outer surface of said tank and is placed between the turns of the main condenser (9).

Description: Title: An Air-Conditioning Plant Technical ' Field The invention relates to an air-conditioning plant for cooling the air in rooms of a building/ such as a 5 single-family house, comprising an evaporator with a cooling surface, a compressor, a main condenser, and a reduction valve connected in a closed circuit for a re¬ frigerant and a blower capable of blowing air through the evaporator, said main condenser being constituted by 10 a substantially helical tube, the turns of which are placed round a hot-water tank in contact with the outer surface of the tank, said main condenser and said hot- water tank being provided with a lagging,such as foam plastic, on the outside. 15. Background Art From German Offenlegungsschrift No. 2,619,722 a heat pump plant is known in which the water in a hot-water tank is heated by the condenser which is wound round the hot-water tank, and in which the hot-water tank with 20 condenser is surrounded by an insulating mantle. The hot-water tank and the condenser are made of different materials, as the tube of the condenser is of copper and thus must be assumed to have a better coefficient of thermal expansion than the hot-water tank. hen the 5 water in the tank is heated, a stratification will arise in a well-known manner so that the temperature will vary- between the uppermost and the lowermost layer of water in the tank, and hot water i * s discharged at the top of the tank. If the cold water at the bottom of the tank 0 has a temperature of e.g. 10°C, and the hot water at the top has a temperature of e.g. 55°C, a difference in tem¬ peratures of 45°C will arise in the tank. This stratifi- cation means that the wall of the tank will have differ¬ ent temperatures in vertical .direction, so that a con¬ denser consisting of copper will expand substantially different from the bottom and upwards, the tube of the condenser expanding more at the top than at the bottom, so that at its top the condenser is released from the tank, and consequently heat cannot be transferred from the condenser tube to the wall of the tank. Disclosure of Invention The object of the present invention is to provide an air- conditioning plant of the type mentioned in the intro¬ duction permitting a secure transfer of heat from the main condenser through the wall of the hot-water tank to the water in the tank. The air-conditioning plant according to the invention is characterised in that the main condenser and the hot- water tank are made of the same type of material. Since the main condenser and the hot-water tank are made of the same type of material it is obtained that although the temperature of the water in the hot-water tank rises with increasing distance from the bottom of the hot- water tank, e.g. from 10°C to 55°C, the wall of the tank and the tube of the main condenser will have substan- tially the same temperature at a given distance from the bottom of the hot-water tank and will consequently ex¬ pand simultaneously. Hereby the contact between the tube of the main condenser and the wall of the tank will be maintained, so that heat is first transferred from the tube of the main condenser to the outer surface of the wall of the tank and then from the inner surface of the wall of the tank to the water in the tank. Further¬ more, holes or cracks are avoided in the tube of the main condenser because of the fact that -by changes in temperature occurring every time cold water flowed into the tank is heated after discharge of hot water, the tube of the main condenser and the wall of the tank will not move relative to each other, whereby friction would arise between them and cause wear and tear. According to the invention the material used may be steel. A main condenser and a hot-water tank are ob¬ tained, which are comparatively cheap to manufacture and have great mechanical strength. Furthermore according to the invention the hot-water tank may be made of an alloy with a better thermal con¬ ductivity than the alloy used for the main condenser. It is hereby obtained that the heat emitted from the main condenser is immediately transferred through the wall of the hot-water tank to the water in the tank. Besides the tube of the main condenser may according to the invention have a triangular, quadrangular or oval cross-section. As a result the tube of the main conden¬ ser has a flat side abutting the outer surface of the hot-water tank which gives an especially good thermal conduction between the main condenser and the hot-water tank. Furthermore according to the invention the. evaporator may be a laminated evaporator. An especially efficient evaporator for air-conditioning plants is hereby ob¬ tained. According to the invention the lubricating oil in the compressor may be cooled by means of a heat exchanger in the form of an oil-cooling condenser located on the out- side of the hot-water tank in contact with the outer sur¬ face of said tank and made of the same type of material C PI as the main condenser and the hot-water tank. It is hereby partly obtained that when the air-conditioning plant functions in the subtropical or tropical zone, the compressor will be cooled suitably, so that its life time is increased considerably, typically from about two to about six years, and it is partly obtained that the heat emitted by the lubricating oil is used, namely to heat water for general use, which will give a further saving of energy. In addition according to the invention the oil-cooling condensor may be constituted by a substantially helical tube, the turns of which are placed round the hot-water tank in contact with the outer surface of said tank, preferably in such a way that the turns of the oil- cooling condenser are located between the turns of the main condenser. As a result a good contact and thus a good thermal conduction are obtained between the oil- cooling condensor and the hot-water tank. Furthermore according to the invention the main condenser and the oil cooling condenser may each be of a height corresponding to about 1/3 of the height of the hot- water tank. It is hereby obtained that the heat ex¬ pansion of the tube of the main condenser and the oil- cooling condenser as well as of the wall of the hot- water tank is reduced to a suitable level. Besides according to the invention a motor-operated valve may be disposed on the hot-water discharge tube of the hot-water tank to ensure that the temperature of the hot water in the hot-water tank ' does not exceed a predeter- mined temperature. By means of this motor-operated valve it is obtained that when the water inthe hot-water tank reaches a ' predetermined temperature, e.g. 55°C and no hot water is used, the motor-operated valve will be C T 'F1 activated to be open for a predetermined period of time. Hot water is thus drained off. the tank and simultaneous¬ ly cold water is flowed into the tank so that the tem¬ perature of the water in the tank drops. The water in the tank is then again ready to receive heat from the main condenser and the oil-cooling condenser. According to the invention a secondary evaporator and a secondary blower may be located above the evaporator and the blower, said secondary blower being capable of blow- ing hot air through the secondary evaporator into the rooms of the building after the hot-water supply has been covered. Such a plant is advantageous in cold weather. When the temperature of the water in the hot- water tank has reached a predetermined temperature, the cooling circuit will shift from the main condenser to the secondary evaporator, and the secondary blower will start blowing hot air into the building through the air- conditioning ducts. If hot water is now tapped from the hot-water tank, the injection of hot air stops, and the injection does not start again until the water in the tank has reached a predetermined temperature. Additionally according to the invention the air-condi¬ tioning plant may be adapted in such a way that in its inlet passage a motor-operated throttle is disposed forrever- sing air from lofts, instead of from channels, in living rooms of the building. When injection of hot air is required, the hot air in the living rooms is not sucked out, but sucked from the loft to be used for generating hot air to be injected into the living rooms, whereby a considerable saving of energy is obtained too. Brief Description of Drawings The invention will be explained below with reference to o;*rι the accompanying drawing, in which Fig. 1 is a substantially vertical sectional view through a first embodiment of an air-conditioning plant according to the invention, Fig. 2 is a top plan view of the air-conditioning plant. Fig. 3 is an outside view of the hot-water tank of the air-conditioning plant and with main condenser and oil- cooling condenser, Fig. 4 is a substantially vertical sectional view through a second embodiment of an air-conditioning plant according to the invention, Fig. 5 is a top plan view of the air-conditioning plant of Fig. 4, Fig. 6 is a schematical view of the cooling circuit for the first embodiment of the air-conditioning plant according to the invention, Fig. 7 is a schematical view of the cooling circuit for the second embodiment of the air-conditioning plant according to the invention, Fig. 8 is on a smaller scale a perspective view of a single-family house, in which an air-conditioning plant according to Figs.4 and 5 with associated duct sys¬ tem has been installed, and Fig. 9 is a schematical sectional view through the house of Fig. 8. Best Mode of Carrying out the Invention The air-conditioning plant shown in Figs. 1 and 2 is primarily adapted by ventilation to cool the air in rooms, e.g. living rooms, in a building, such as a single- family house, a flat or similar residence. The air cooled by the air-conditioning plant is blown through a duct system into the rooms to be cooled, and from here the air is sucked out via a duct through e.g. a vent pipe in the roof, or it is recirculated if so desired. The air-conditioning plant is constructed as a vertical compact unit consisting of a comparatively large lower section la. and a smaller upper section lb detachably • ; connected with the lower section la. Each of the sec¬ tions la and lb is preferably built up of an angle-iron frame enclosed in plates, the section la being buit up by interconnected horizontal and vertical frame bars 2a and 2b, respectively, of angle-iron. A number of ad¬ justing screws 3 is fastened to the underside of the horizontal frame bars 2a.. At the top the air-condition¬ ing plant comprises a top plate 4 (Figs. 1 and 2) provid- ed with an inlet opening 5 for the air to be cooled and an outlet opening 6 for the air which has been cooled in the air-conditioning plant and is ready for injection into the rooms of a building. As it appears from Fig. 1 and the diagram in Fig. 6 the air-conditioning plant comprises an evaporator 7 with a cooling surface, a compressor 8, a main condenser 9, a receiver 25, a dry filter 26 and a reduction valve 27 in the form of a thermostatic expansion valve, which by means of connecting lines (Fig. 6) is connected in a closed cooling circuit, in which a refrigerant, e.g. Freon 502, is circulated. Furthermore, the air- conditioning plant comprises a blower 10 capable of blowing air through the evaporator 7 and a vertical hot- water tank 11 located centrally in the lower section la. . < '*° An almost circular supporting flange 11a of angle-iron is secured on the outside of the hot-water tank 11, said supporting flange resting on top of the vertical frame bars 2b, whereby transfer of heat from the tank 11 to : the frame bars 2b is substantially avoided. As it appears from Fig. 1, the blower 10, the evaporator 7 and the compressor 8 are located in the upper section lb of the air-conditioning tank above the hot-water tank 11. The adjusting screws 3 serve to adjust the angle-iron frames 2a, 2b in such a way that the compres¬ sor 8 is in exactly vertical position. The main condenser 9 is constituted by a substantially helical tube, the turns of which are indicated by solid lines in Figs. 1 and 3 and are placed round the hot- water tank 11 in contact with the outer surface of the tank. The main condenser 9 and the hot-water tank 11 are on the outside provided with a lagging 12 of e.g. foamed polyurethane or a similar foam plastic. The upper section lb is provided with a lagging 12a of simi- lar material. On the underside the lagging 12 is provided with a drain pipe 13 for condensed water. On the underside of the lagging 12 there is also a stud 14 for a cold water inlet pipe 15 projecting a short distance into the hot-water tank 11, and a stud 16 for a hot-water discharge pipe 17 extending through the hot-water tank 11 almost to its upper end bottom. When the air-conditioning plant is in operation, the blower 10 sucks the air to be cooled through the inlet opening 5 and blows it through the evaporator 7 provid- ed with a cooling surface and out through the outlet opening 6, from which the cooled air is injected through a duct system into the rooms to be cooled of the resi¬ dence. When the air is flowing along the cooling sur¬ face of the evaporator 7, the air is cooled as well as C-/II dehydrated, and consequently the air humidity in the residence is regulated too. • In the closed cooling circuit formed by the evaporator 7, the compressor 8, the main condenser 9 and the reduc- tion valve 27 the refrigerant in the evaporator 7 will absorb the heat emitted by the air and evaporate. The refrigerant vapour is conveyed to the main condenser 8, where it is compressed and then conveyed to the main condenser 9, where the refrigerant vapour is condensed while heat is emitted. The condensed refrigerant is then conveyedto ' the receiver 25 and from there on through the dry filter 26. The refrigerant is then con¬ veyed to the reduction valve 27 and through this valve during a great drop in pressure and flows at low pres- sure back to the evaporator 7, whereby the cyclic process is completed. The heat which the condenser 9 emits by thermal conduc¬ tion through the wall of the hot-water tank 11 to the water in the tank contributes to heating the water in the hot-water tank 11, so that the hot water can be used as hot water for general use. The amount thus pro¬ duced of hot water for general use deriving from the cooling of the air in the evaporator 7 is of such a size that it amply covers the consumption of hot water in an ordinary family. The hot water is tapped from the discharge pipe 17. The main condenser 9 and the hot-water tank 11 are made of the same type of material. It is hereby obtained that although the temperature of the water in the hot- water tank 11 rises with increasing- distance from the bottom of the hot-water tank 11, e.g. from 10°C to 55°C the wall of the tank 11 and the tube of the main conden¬ ser 11 will have substantially the same temperature and C-.ΪFI consequently expand simultaneously at a given distance from the bottom of the hot-water tank 11. Hereby the contact between the tube of the main condenser 9 and the wall of the hot-water tank 11 will be maintained so that heat is first transferred from the tube of the main condenser 9 to the outer surface of the wall of the tank 11 and then from the inner surface of the wall of the tank 11 to the water in the tank 11. Furthermore holes or cracks are avoided in the tube of the main condenser 9 because of the fact that by changes in tem¬ perature occurring every time cold water flowed into the tank 11 is heated after discharge of hot water, the tube of the main condenser 9 and the wall of the tank 11 will not move relative to each other, whereby friction would arise between them and cause wear and tear. The material used for the main condenser 9 and the hot water tank 11 is preferably steel. A main condenser 9 and a hot water tank 11 are thus obtained which are com¬ paratively cheap to manufacture and have great echani- can strength. The hot-water tank 11 may advantageously be made of an alloy with a better thermal conductivity than the alloy .used for the main condenser 9. It is hereby obtained that the heat emitted from the main condenser 9 is immediately transferred through the wall of the hot- water tank 11 to the water in the tank 11. The tube of the main condenser 9 may have a triangular, quadrangular or oval cross-section. As a result the tube of the main condenser 9 has a flat side which may abut the outer surface of the hot-water tank 11 which will give an especially good thermal conduction between the main condenser 9 and the hot-water tank 11. cvπ The evaporator 7 may advantageously be a laminated evaporator. An especially efficient evaporator is there¬ by obtained with a comparatively large cooling surface capable of receiving large quantities of heat from the air per unit of time. The lubricating oil of the compressor 8 may be cooled by means of a heat exchanger in the form of an oil-cooling condenser 18 (Figs. 1, 3, and 6) located on the outside of the hot-water tank 11 in contact with the outer sur- face of the tank and made of the same type of material as the main condenser 9 and the hot-water tank 11. It is hereby partly obtained that when the air-conditioning plant functions in the subtropical or tropical zone, the compressor 8 will be cooled suitably, so that its life time is increased considerably, typically from about 2 to about 6 years, and it is partly obtained that the heat emitted by the lubricating oil is used, namely to heat the water for general use which will give a further saving of energy. During operation of an air-conditioning plant with coupled-in oil-cooling condenser 18 as shown in Fig. 6 the compressor 8 will send compressed refrigerant gas into the main condenser 9. The gas is cooled there, whereby it condenses partly. The mixture of gas and condensate is conveyed through the oil-cooling spiral 28, where it evaporates and absorbs heat from the com¬ pressor 8. The final condensation takes place in the oil-cooling condenser 18, and the condensate is accumu¬ lated in the receiver 25. The oil-cooling condenser 18 is constituted by a sub¬ stantially helical tube, the turns of which are indicat¬ ed by dotted lines in Figs. 1 and 3 and are placed round the hot water tank 11 in contact with the outer surface of said tank 11, preferably in such a manner that the turns of the oil-cooling condenser 18 are situated be¬ tween the turns of the main condenser 9. Hereby a good contact and thus a good thermal conduction are obtained between the oil-cooling condenser 18 and the hot-water tan 11. The main condenser 9 and the oil-cooling condenser 18 are each of a height corresponding to about 1/3 of the height of the hot-water tank 11. As a result the heat expansion of the tube of the main condenser 9 and of the tube of the oil-cooling condenser 18 as well as of the wall of the hot-water tank 11 is reduced to a suitable level. A motor-operated valve 19 is disposed at the bottom of the hot-water discharge pipe 17 on the hot-water tank 11 to ensure that the temperature of the hot water in the hot-water tank 11 does not exceed a predetermined tempe¬ rature, e.g. 55°C. Such a motor-operated valve 19 is advantageous under certain climatic conditions with much heat, where an overproduction of hot water will often occur, i.e. when the water in the hot-water tank 11 has reached the predetermined temperature, and no hot water is used. In this case the motor-operated valve 19 is activated to be open for a predetermined period of time, whereby some ' hot water is drained from the tank 11 through the discharge pipe 17, and simultaneously cold water is charged into the tank 11 through the inlet pipe 15, so that the temperature of the water in the tank 11 drops. The water in the tank 11 is then again ready to absorb heat from the heat condenser 9 and the oil-cool¬ ing condenser 18. The motor-operated valve 19 may ad¬ vantageously be activated automatically by a signal from a temperature detector 20 located at the top of the hot- water tank 11. The hot water discharged can e.g. be used in swimmming pools or the like, or as far as flats are concerned be connected to a central hot-water supply plant. The air-conditioning plant may be electronically con¬ trolled from a control panel 21 (Figs. 1 and 2) advan- tageously located at the front side of the air-condition¬ ing plant. On said control panel 21 e.g. the tempera¬ ture of the hot water for general use and the velocity of the air exchange may be adjusted. In Figs. 4 and 5 a second embodiment of the air-condi- tioning plant is shown, and in Fig. 7 a diagram for the associated cooling circuit is shown. The second embodi¬ ment differs from the embodiment of Fig. 1 by the fact that a secondary evaporator 22 and a secondary blower 23 are located above the evaporator 7 and the blower 10, ' respectively. At the top the air-conditioning plant of Fig. 4 further comprises a top plate 24 provided with four apertures 29, 30, 31, and 32 (Fig. 5) . The secon¬ dary blower 23 can blow hot air into the rooms of a building through the secondary evaporator -22, after the hot-water supply has been covered. Such a plant is ad¬ vantageous in cold weather. When the temperature of the water in the hot-water tank 11 has reached a predetermined temperature, e.g. 55 C, the cooling cir¬ cuit shifts by means of a three-way-valve 35 (Fig. 7) from the main condenser 9 to the secondary evaporator 22 now operating as condenser, and the secondary blower 23 starts blowing hot air into the building through the air-conditioning ducts. If hot water is now tapped from the hot-water tank 11, the injection of hot air stops, and the injection does not start again until the water in the tank 11 has reached a predetermined temperature. In the inlet passage of the air-conditioning plant a motor-operated throttle (not shown) may be disposed for reversing air from lofts instead of from ducts to the living rooms of the residence. At 33 the reversing is effected by means of a motor-operated throttle between the ducts 29a and 31a, and at 34 the reversing is effec¬ ted by means of a motor-operated throttle between the ducts 30a and 32a. After the motor-operated throttle has been closed, the air is sucked from the loft through an inlet opening 29 in the top plate 24. The air is then conveyed through the primary evaporator 7, where¬ by the air is cooled and conveyed on out through the inlet opening 30 in the top plate 24 and blows out over the roof (cf. Figs. 8 and 9), as the motor-operated throttle in closed position will turn off the injection into the living room. Through an inlet opening 31 at the top of the top plate 24 return air is sucked in from the living rooms, and the air is conveyedthrough the secondary evaporator/condenser 22, and thus heated, and on through an outlet opening 32 in the top plate 24. The suction-in through the inlet opening 31 and the blow- -ing-out through the outlet opening 32..are then reversed to recirculate the air in the existing duct system.

Claims: Claims 1. An air-conditioning plant for cooling the air in rooms of a building,, such as a single-family house, com¬ prising an evaporator (7) with cooling surface, a com¬ pressor (8), a main condenser (9) and a reduction valve (27) connected in a closed circuit for a refrigerant and a blower (10) capable of blowing air through the evapo¬ rator (7) , said main condenser (9) being constituted by a substantially helical tube, the turns of which are placed round a hot-water tank (11) in contact with the outer surface of the tank, said main condenser (9) and said hot-water tank (11) being provided with a lagging, such as foam plastic, on the outside, c h a r a c¬ t e r i s e d in that the main condenser (9) and the hot-water tank (11) are made of the same type of material. 2. An air-conditioning plant as claimed in claim 1, c h a r a c t e r i s e d in that the material used is steel. 3. An air conditioning plant as claimed in claim 1 or 2, c h a r a c t e r i s e d in that the hot-water tank (11) is made of an alloy with a better thermal con¬ ductivity than the alloy used for the main condenser (9) . 4. An air-conditioning plant as claimed in claim 1, 2 or 3, c h a r a c t e r i s e d in that the tube of the main condenser (9) has a triangular, quadrangular or oval cross-section. 5. An air-conditioning plant as claimed in claims 1- 4, c h a r a c t e r i s e d in that the evaporator (7) is a laminated evaporator. 6. An air-conditioning plant as claimed in any of claims 1-5, c h a r a c t e r i s e d in that the lub¬ ricating oil in the compressor (8) is cooled by means of a heat exchanger in the form of an oil-cooling condenser (18) located on the outside of the hot-water tank (11) in contact with the outer surface of said " tank and made of the same type of material as the main condenser (9) and the hot-water tank (11) . 7. An air-conditioning plant as claimed in claim 6, c h a r a c t e r i s e d in that the oil-cooling con¬ denser (18) is constituted by a substantially helical tube, the turns of which are placed round the hot-water tank (11) in contact with the outer surface of said tank, preferably in such a way that the turns of the oil-cooling condenser (18) are located between the turns of the main condenser (9) . 8. An air-conditioning plant as claimed in claim 6 or 7, c h a r a c t e r i s e d in that the main con¬ denser (9) and the oil-cooling condenser (18) each is of a height corresponding to about 1/3 of the height of the hot-water tank (11) . 9. An air-conditioning plant as claimed in any of the preceding claims, c h a r a c t e r i s e d in that a motor-operated valve (19) is disposed on the hot- water discharge tube (17) of the hot-water tank (11) to ensure, that the temperature of the hot water in the hot- water tank (11) does not exceed a predetermined tempera¬ ture. 10. An air conditioning plant as claimed in any of the preceding claims, c h a r a c t e r i s e d in that a secondary evaporator (22) and a secondary blower (23) are located above the evaporator (7) and the blower (10) , said secondary blower (23) being capable of blowing hot air through the secondary evaporator (22) into the rooms of the building after the hot-water supply has been covered. 11. An air conditioning plant as claimed in claim 10, c h a r a c t e r i s e d in that in its inlet pas¬ sage a motor-operated throttle is disposed for reversing air from lofts, instead of from channel, to living rooms in the building. c

Inventors: VIUFF CARL-JOHAN KOFOD FINNEMA, VIUFF, CARL-JOHAN, KOFOD, FINNEMANN
Applicants: VIUFF CARL JOHAN KOFOD FINNEMA, VIUFF, CARL-JOHAN, KOFOD, FINNEMANN
Application year: 1983
Main classification: F24F5
IPC codes: F24D17, F24F1, F24F5, F24H4, F25B5, F25B31