A BOILER ARRANGEMENT

Abstract: A boiler arrangement for heating the heat-transfer medium, such as water, of a heating system utilizing water-carried heat. The boiler comprises a vessel (2) containing the heat-transfer medium; a combustion chamber (3) in heat conductive connection with the heat-transfer medium in the vessel (2); smoke pipes (4) which extend from the combustion chamber (3) down through the vessel (2) and discharge at the bottom of the vessel into an exhaust-gas collecting chamber (5). The vessel (2) is provided in its upper part with an outlet (7) leading to the inlet line of the heating system, and beneath the outlet (7) with an inlet (8) from the exhaust line of the heating system. One or more additional heating circuits (14) located externally of the boiler and having an outlet (15) from the vessel (2) are arranged so as to obtain additional cooling of the heat-transfer medium in the lower part of the vessel (2). The outlet (15) from the vessel (2) to the additional heating circuit or circuits (14) lies beneath the inlet (8) from the exhaust line of the heating system, and the return-water inlet from the heating circuit or circuits (14) is connected to the lower part of the vessel (2).

Description: A boiler arrangement The present invention relates to a boiler• arrangemen for heating a heat-transfer medium, such as water, in a heating system utilizing water-carried heat, said system comprising a vessel containing the heat-transfer medium; a combustion chamber in heat-conductive connection with th heat-transfer medium; smoke pipes which extend from the combustion chamber, down through said vessel, and discharg into a combustion-gas collecting chamber; the vessel con¬ taining the hea -transfer medium having arranged in its • upper part an outlet which leads to the inlet line of the heating system, and beneath said outlet an inlet from the exhaust line of said system. Known to the art are heating systems utilizing water-carried heat in which the radiators of the radiator system have relatively small radiating surfaces, ' resulting in high-tempe axure return water. When a boiler of the above-mentioned kind is used to heat the heat-transfer medium in such a radiator system, the smoke gases are not cooled to a satisfactorily low temperature ^ as they pass down through the smoke pipes, and consequently the tempera¬ ture of the smoke gases is not low enough to enable steam carried " by the smoke to condense. This means that no heat will be generated by steam condensation, resulting - inter alia - in unnecessary heat losses . An object of the invention is to provide a boiler arrangement of the aforementioned kind in which these dis¬ advantages are substantially overcome. Accordingly, there is provided externally of the boiler an additional heating circuit which can be connected to the lower part of said boiler. The boiler connections of this additional heating circuit are located beneath the -boiler connections of the main heating circuit . The circuit is dimensioned so that τhe temperature of the return water is below 50 C. As a result of this additional heating circuit, the temperature of The return water at the lower part of the aforesaid vessel can be below 50°C. Thus, the invention OMPI provides a heating system in which the return water from the additional circuit is colder than the return water from the conventional part of the heating system. The additio¬ nal heat which can be taken from the additional heating circuit is about 10 - 20% of the heat delivered by the boiler. The additional heating circuit may include a so- called aerotemper, i.e. a heat exchanger in which a fan blows air over flanged pipes , or comprises additional radiators . The additional heating circuit may also com- prise a closed system carrying water mixed with glycol, for heating the entrances to garages and passages . In this case, the boiler water is cooled indirectly by a loop or coil located beneath the return-water inlet from the conventional or main heating system. This closed cooling system may also be incorporated as a τhird cooling system in the heating system, in which case said closed cooling system is located beneath the return-water inlet from the additional heating circuit in which the boiler water flows . In this way extremely good layering of the ' ' emperature of the boiler water in the bottom part of the" vessel is obtained. An exemplary embodiment of the invention will now be described in more detail with reference to the accompany¬ ing schematic drawing. The illustrated exemplary embodiment of the boiler arrangement according to the invention comprises a boiler casing 1 which encloses a vessel 2 containing heat-trans¬ fer medium, which in the illustrated example comprises preferably water. Smoke pipes 4 extend downwardly from a combustion chamber 3 to a smoke-gas collecting chamber 5. An exhaust gas connection 6 extends from the collect¬ ing chamber 5 to a chimney. Arranged in the upper part of the vessel 2 is an outlet 7 connected to the input line of the heating system, while an inlet 8 from the exhaust line of the heating system is arranged in the lower part of said vessel. The exhaust line is coupled to radiators 12 and 13 through a shunt valve 9 and a pump 11. The total radiating surface of the radiators 12, 13 is relatively small, resulting in a relatively high OMPI V FO temperature of the return water at the inlet 8. In order to obtain good heat exchange with the s oke gases flowing down through the smoke pipes 4 it is necessary for the temperature of the boiler water in the lower part of the vessel 2 to be as low as possible, preferably beneath about 50 C, so that heat generated by the condensation of steam carried by the gases can also be utilized. Because the temperature of the return water at the inlet 8 is above 50°C, the illustrated boiler is provided with an additional heating circuit 1*+ provided with a boiler- outlet to said additional circuit located beneath the return-water inlet 8. The boiler water is circulated "in the circuit 14- by means of a pump 16. The water circulat¬ ing in the circuit 14- is returned to the vessel 2 through an inlet 17. The additional circuit 14 is so dimensioned that the water returned to the vessel 2 has a temperature below 50°C. Optionally, the circuit 14 may comprise a closed system, in which case an additional loop or coil is arranged within the vessel 2, hetween the outlet 15 and the -inlet 17. The boiler water heats the water in the coil, which may contain, for example, water mixed with glycol for heating, for example, garage entrances or passages with the aid of the circuit 14, which in this case comprises a loop or coil buried beneath the garage entrance or passageway. The vessel 2 also includes a tap water reservoir 18, comprising a lower and an upper part, for heating tap water. The inlet 19 of the tap-water reservoir leading to the vessel 2 is connected to a fresh cold-water line and lies beneath the level of the inlet 17 from the addi¬ tional heating circuit 14. The tap-water reservoir 18 contributes to further layering of the temperature in the bottom part of the vessel 2 into different temperature zones . In accordance with a particular embodiment of the invention, the additional heating coil may also be used o pre-heat combustion air. OMPI

Claims: CLAIMS ; 1. A boiler arrangement for heating heat-transfer medium, such as water, in a heating system using water- carried heat, said boiler arrangement including a vessel (2) containing the heat-transfer medium; a combustion chamber (3) in heat-conductive connection with the heat- transfer medium in the vessel (2); smoke pipes (4) which extend from the combustion chamber (3) down through said vessel (2) and discharge into a combustion-gas collect¬ ing chamber (5); the vessel (2) containing the heat- transfer medium having arranged in its upper part an out¬ let (7) which leads to the inlet line of the heating system, and an inlet (8) from the exhaust line of said system located bene.ath said outlet (7), characterized by at least one additional heating circuit (14) located externally of the boiler and having a vessel-outlet (15) located beneath the inlet (8) from the exhaust line of the heating system and inlet (17) to the vessel (2) in the lower part of said vessel, where the lower circuits are dimensioned so that the temperature of the return water is below 50°C, to enable the heat of condensation of steam carried by the smoke gases to be utilized. 2. A boiler arrangement according to claim 1 , characterized in that arranged in the vessel (2) is a reservoir or loop (18) for heating tap water, the lowest part (19) of the tap water reservoir lying beneath the level of the inlet (17) from the additional heating cir¬ cuit (14) located externally of the boiler. 3. A boiler arrangement according to claim 1 or claim 2 , characterized by a f rther heating circuit additional to said additional heating circuit , comprising a closed system which contains water mixed with glycol.

Inventors: BERNSTEIN RAGNAR
Applicants: BERNSTEIN RAGNAR, FAGERSTA AB
Application year: 1982
Main classification: F24H1
IPC codes: F24D3, F24H1, F24H8