GB2174799A

GB2174799A - Central heating system

Info

Publication number: GB2174799A
Application number: GB08610988A
Authority: GB
Inventors: Veit Merges
Original assignee: Messerschmitt Bolkow Blohm AG
Current assignee: Airbus Defence and Space GmbH
Priority date: 1985-05-10
Filing date: 1986-05-06
Publication date: 1986-11-12
Anticipated expiration: 2006-05-06
Also published as: DE3516962C2; FR2581741B3; FR2581741A1; JPS61265443A; GB8610988D0; DE3516962A1; GB2174799B

Abstract

An oil or gas-fired hot water domestic heating system comprises a burner (10) and a heating boiler (12) with a continuous flow of water, and one or more Stirling units (11, 11a, 11b) which extract heat from the surrounding air (19) or from the waste air (14) from the dwelling and pump it up to the temperature level of the heating water, the burners and the boilers being arranged so that they are automatically controlled, particularly on cold days, and are capable of heating the house sufficiently without the assistance of water pumps. <IMAGE>

Description

SPECIFICATION Domestic. heating systems This invention relates to an oil or gas fired hot water domestic heating system comprising a burner and a heating boiler with a continuous flow of water.

Apparatus of this kind is known in a number of forms each of which suffers from certain disadvantages rendering them uneconomical. One system requires expensive absorbers for the heat of the surrounding air. Another system is equipped with an electric heat pump drive and provides no saving of primary energy whereas systems driven by diesel motors are not only expensive, maintenance-intensive and produce harmful emissions but also call for costly sound insulation measures. Almost all systems require, in the event of external temperatures of below 0 C as example, an independent bivalent equipment and they are thus uneconomical for this reason.

This invention seeks to provide a domestic heating system which will be free of the aforementioned disadvantages since it allows bivalent use of the burner and the boiler and requires no electric drive.

According to this invention there is provided oil or gas-fired hot water domestic heating systems comprising a burner and a heating boiler with a continuous flow of water, which are controlled by a temperature control, in which system a Stirling engine is directly associated with the burner and a Stirling heating pump, a cooling system for the Stirling motor being directly associated with the heating boiler and a continuous flow of water and an overheating prevention system and an air sup ply automatically adapted to the external temperature by an adjustable temperature control.

Embodiments according to the invention are shown by way of example in the accompanying drawings, wherein: Figure 1 shows a schematic diagram of a config uration of an oil-fired hot water heating system.

Figure 2 shows a schematic diagram of a typical flow of energy for the system shown in Figure 1, and Figure 3 shows a schematic diagram of a config uration of a gas fired domestic heating system.

Referring to the drawings, the configuration illustrated in Figure 1 shows a construction of an oilfired hot water domestic heating system with a heat pump allowing dual use of the heating com ponents required for a bivalent system and dispen sing with the absorber hitherto required outside the dwelling. In addition, the heat content of the stale indoor air requiring to be changed is used si multaneously with the heating and ventilating process. For this purpose a Stirling unit consisting of a Stirling engine 11 and a Stirling heat pump 11a is inserted in the base of an oil-fired hot water boiler 12 and conveys the heat from air in the room to the hot-water system.The Stirling engine 11 is positioned in the combustion chamber of the heating boiler 12 in such a way that the heater head or heads 11c are situated in the actual flame zone of the burner 10 and are heated thereby. The remaining waste heat from the flue gas is also given off to the boiler, as is usual. The aforementioned heater head 11c does not become overheated even if the engine is shut off, since the flue gases are then deflected by a protective device 18.

The air in the room, mainly taken in by suction by fan 15 via air ducts 14 and miscible with the surrounding air 19 is cooled in the Stirling heat pump or the ducts (air) and the heat receiving device 11b and is exhausted externally through a channel 17 provided with heat insulation 17a. To the same extent as the stale air flows out of the rooms, heated fresh air is introduced through apertures in the outer wall and heated by the heating unit through which water flows.

In a special constructional example a number of units comprising a Stirling motor 11 and a Stirling heat pump 11a should be positioned on a modular principle in the base of the heating boiler 12. This enables an ample power range to be covered with a relatively small Stirling unit 11, 11a, 11b, 11c designed as a constructional module, inasmuch as one, two three or more such modules, according to need, can be installed in the water boiler 12 or the base thereof. From the point of view of manufacture, this greatly simplifies the system, as only one size need be produced. Thus, a unit with an output of 3 kW can provide power for the boiler of about 4 kW, 8kW or 12 kW, according to whether the system is equipped with one, two or three such units.

As the operation of the burner is confined, for example, to days on which the ambient temperature is below 0 C (bivalence), the burner and boiler are each designed for twice the power.

Figure 2 illustrates the flow of energy for an oilfired hot water domestic heating system described in the foregoing, the assumed values being as follows: (a) An efficiency of 45/70 = 0.64 for the burner.

(b) An efficiency 15/45 = 0.33 for the Stirling engine.

(c) a performance figure of 45/15 = 3 for the heat pump.

A typical thermal coefficient is approximately 1.4.

Apart from the rationalisation of power, the plant provides, without necessitating any greater current consumption, a saving of between 1/4 and 1/3 of the fuel consumption hitherto involved. The configuration proposed ensures reliable redundancy, since if the Stirling units fail the remaining parts of the plant, which in extreme cases may mean simply the heating of the burner, remain operative at all times.

Figure 3 illustrates a gas-fired domestic heating system constructed according to the system described on the foregoing. Here again, the function is similar to that described and the problem is solved to a similar extent. It should be added that existing gas-fuelled systems and also existing oilfired plant can be converted in the manner described without presenting any problems.

Claims

1. Oil or gas-fired hot water domestic heating systems comprising a burner and a heating boiler with a continuous flow of water, which are controlled by a temperature control, in which system a Stirling engine is directly associated with the burner and a Stirling heating pump, a cooling system for the Stirling motor being directly associated with the heating boiler and a continuous flow of water and an overheating prevention system and an air supply automatically adapted to the external temperature by an adjustable temperature control.

2. A domestic heating system in accordance with Claim 1, wherein a number of units comprising a Stirling engine and a Stirling heat pump are mounted in modular forms on the heating boiler with a continuous flow system and are controlled together by a temperature regulator.

3. A domestic heating plant in accordance with Claim 1 or 2, wherein the heater head or heads of the Stirling engines are situated in the actual flame zone of the oil or gas fired burner.

4. A domestic heating system in accordance with any one of Claims 1 to 3, wherein the energysupplying air is fed to the heat pump by manual or automatic control either from the surroundings or through air ducts from rooms in the dwelling or from both simultaneously, air then leaving the dwelling via a heat-insulated duct with a fan serv- ing as an air conveying means.

5. A domestic heating system in accordance with Claims 1 to 4, wherein the unit comprising the Stirling engine and the Stirling heat pump is installed in a removable and replaceable manner in the place of operation.

6. A domestic heating system in accordance with any one of Claims 1 to 5, wherein a number of Stirling units are provided in a fail-safe arrangement ensuring direct flame heating in the event of a failure of one or all said units.

7. A domestic heating system constructed and arranged to function as described herein and exemplified with reference to the drawings.