Heating systems – Heat and power plants
Patent
1994-10-28
1996-08-20
Tapolcai, William E.
Heating systems
Heat and power plants
290 2, F24D 500
Patent
active
055471277
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method for extracting thermal energy for use in a heat distributing plant and of the kind stated in the preamble of claim 1, as well as to a combined heat and power plant for performing the method.
Heat distributing plants are normally supplied with thermal energy from a boiler fired by coal, oil or gas, but recently heat distributing plants have been built or planned, in which a major or smaller part of the thermal supply derives from cooling of an internal combustion engine driving a generator coupled in the public electricity supply system. The most common form of such heat distributing systems supply district heating to dwelling houses, and in the following the term district heating system is used generally about such heat distributing plants. It is normal practice to equip smaller generators with a shaft-driven ventilator, which is normally somewhat oversized and which circulates the air surrounding the generator around its electrical windings. To attain sufficient cooling the ambient air should be kept at a comparatively low level. To avoid noise nuisances the generator and the motor are usually placed in the same sound-absorbing cabinet, and it should therefore be ventilated to such an extent that sufficient cooling of the generator is attained. In the plant thus outlined, the heat, which is present in the used ventilation air, will be discarded due to the fact that it is present at a temperature level, at which it cannot be exploited in the district heating system without a heat pump.
The heat loss, which has up until now been accepted it such a combined heat and power plant, amounts to approx. 12-15% of the effect fired into the plant, but even though the loss is considerable, it has on account of the low temperature level of this amount of heat not been considered profitable to recover it.
From the specification to U.S. Pat. No. 4,680,478 a gas engine generator plant with heat recovery built into a closed, sound-absorbing cabinet is known. In this plant a ventilator ensures the presence of a cooling air flow in the cabinet, the cooling air passing in its flow path in series condensing heat exchangers for exhaust gas from the engine, the generator, the cooling ribs of the motor and a primary exhaust gas cooler. The cooling air is supplied in comparatively big amounts to ensure an effective cooling of the various components, and the cooling air outlet therefore only reaches a temperature of approx. 55.degree. C., which is not sufficient for heating circulation water in the heat distributing system, but only sufficient for being used for direct in-blowing in an air-heated house, which on account of the difficulties in connection with transferring air heat over bigger distances should be present in the immediate vicinity of the generator plant. The direct contact between the cooling air used for heating and the cooled machines entails a risk of obnoxious smells and exudation of hydrocarbon.
EP-A-0 152 121 discloses a heat pump apparatus. Thermal energy is extracted for use in a heat distribution plant from a generator plant having an air cooled generator enclosed in a common cabinet together with a combustion engine. The generator is cooled with the ventilation air passing through the cabinet. Thermal energy from the cooling system and exhaust gas is transferred to the district heating system. The cooling air from the generator constitutes part of the ventilation air in the cabinet and is part of the low temperature heat source for the heat pump. In the known apparatus a heat pump is an indispensable component, which adds to the cost and maintenance of the apparatus.
The object of the present invention is to provide a method for profitable recovery of essential parts of the amount of heat mentioned in connection with district heating systems and avoiding the complication of using a heat pump. The invention exploits the sound-absorbing cabinet for reduction of the dissipation of heat to the surroundings and is based on the perception that the engine has a considerabl
REFERENCES:
patent: 2961550 (1960-11-01), Dittman
patent: 4657290 (1987-04-01), Linden
patent: 4680478 (1987-07-01), Wicks
patent: 4736111 (1988-04-01), Linden
patent: 4951871 (1990-08-01), Hata et al.
Madsen S.o slashed.ren M.
Stromvig Jan
Clarke Dennis P.
Kruger Systems AS
Tapolcai William E.
LandOfFree
Method for utilization of heat energy in a district heating netw does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for utilization of heat energy in a district heating netw, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for utilization of heat energy in a district heating netw will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2324770