WO1997035153A1

WO1997035153A1 - Thermo-electric boiler arrangement

Info

Publication number: WO1997035153A1
Application number: PCT/GB1997/000730
Authority: WO
Inventors: David Michael Rowe; Gao Min
Original assignee: University College Cardiff Consultants Limited
Priority date: 1996-03-16
Filing date: 1997-03-17
Publication date: 1997-09-25
Also published as: AU2033897A; GB9605561D0; JP2000506964A

Abstract

A boiler arrangement comprises a heat source (2) and passages (4, 6, 8) for the through-flow of fluid to be heated by the heat source, and further comprises one or more thermo-electric or Seebeck devices (14) situated between the heat source and the heating fluid flow passages to generate an EMF according to the temperature differential between them. The EMF may be used, for example, to power a pumping device (10).

Description

Thermo-Electric Boiler Arrangement

The present invention relates to a boiler arrangement, particularly for a heating system.

Existing domestic and commercial heating systems rely upon an external electrical power supply to pump water through a boiler or other heat-exchanging device and around a heat distribution circuit. Such systems are therefore inherently vulnerable to a failure of that electricity supply.

We have now devised an alternative boiler arrangement which overcomes this limitation by independently generating its own internal electrical power supply.

In accordance with the present invention there is provided a boiler arrangement comprising a heat source and passages for the through-flow of fluid to be heated by said heat source, and further comprising one or more thermo-electric or Seebeck devices situated between said heat source and said heating fluid flow passages to generate an EMF according to the temperature differential between them.

Preferably the generated EMF supplies a pumping device to pump said heating fluid through the boiler arrangement and around a heat distribution circuit.

Preferably said one or more thermo-electric or Seebeck devices comprise a plurality of fins, ribs or other surface features to increase the efficiency of thermal conduction from the heat source or to the heating fluid. Preferably said one or more thermo-electric or Seebeck devices comprise a binary, ternary or quaternary combination of metals selected from Silver, Lead, Tellurium, Bismuth, Antimony, and Selenium. Most preferably said one or more thermo-electric or Seebeck devices comprise Lead Telluride devices.

Preferably the temperature of the heat source is between 100 and 1000 degrees centigrade and the temperature of the heating fluid is between 50 and 100 degrees centigrade so that the temperature differential between them is between 400 and 950 degrees centigrade.

Preferably the heat source is a fossil fuel burner. Preferably the heating fluid comprises water drawn from a mains water supply.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings in which:

FIGURE 1 is a schematic illustration of a prior art boiler arrangement used for a central heating system; and,

FIGURE 2 is a schematic illustration of a thermo¬ electric boiler arrangement in accordance with the present invention also used for a central heating system.

Referring to Figure 1 of the drawings, a prior art boiler arrangement (either gas-fired or oil-fired) is shown, comprising a heat source 2 and a re-circulating water supply 4,6,8. Cold water from an inlet conduit 4 is pumped through the boiler by a pumping device 10, where it is heated by the heat source 2. The resulting heated water passes out through an outlet conduit 8 and around a heat distribution circuit (not shown) to return again via inlet conduit 4. Pumping device 10 operates via an external electrical power source 12, and therefore the boiler arrangement is susceptible to a failure of this supply, due for instance to a power cut.

Figure 2 illustrates a boiler arrangement (again either gas-fired or oil-fired) in accordance with the present invention in which thermo-electric devices 14 are arranged to generate an electrical supply 16. The thermo-electric devices have one side towards the high temperature heat source 2 and their opposite side towards the low temperature water supply

6. The independent supply is used instead of the external supply 12 to power the pump 10. Typically, the thermo-electric devices are less than 10% efficient and therefore do not significantly effect the flow of heat from the heat source 2 to the circulating water. Preferably, the thermo-electric devices are Lead and Bismuth based Telluride devices whose structure and performance are most suited to operation at high temperatures.

The arrangement of Figure 2 is clearly an improvement over that of the prior art in that its internal power supply mechanism allows it to operate independently of the electrical mains supply. Whilst the example described uses the thermo- electrically generated EMF to supply a pumping device, it would remain in accordance with the present invention for the generated EMF to supply additional devices, e.g. a control unit of the heating system.

Claims

Cla ims

1) A boiler arrangement comprising a heat source and passages for the through-flow of fluid to be heated by said heat source, and further comprising one or more thermo-electric or Seebeck devices situated between said heat source and said heating fluid flow passages to generate an EMF according to the temperature differential between them.

2) A boiler arrangement as claimed in Claim 1, wherein said generated EMF supplies a pumping device to pump said heating fluid through the boiler arrangement and around a heat distribution circuit.

3) A boiler arrangement as claimed in Claim 1 or 2, wherein said one or more thermo-electric or Seebeck devices are formed with a plurality of fins, ribs or other surface features to increase the efficiency of thermal conduction from said heat source or to said heating fluid.

4) A boiler arrangement as claimed in any preceding claim, wherein said one or more thermo-electric or Seebeck devices comprise a binary, ternary or quaternary combination of metals selected from Silver, Lead, Tellurium, Bismuth, Antimony, and Selenium.

5) A boiler arrangement as claimed in Claim 4, wherein said one or more thermo-electric or Seebeck devices comprise Lead Telluride devices.

6) A boiler arrangement as claimed in any preceding claim, arranged so that, in use, the temperature of said heat source is between 100 and 1000 degrees centigrade and the temperature of said heating fluid is between 50 and 100 degrees centigrade so that the temperature differential between them is between 400 and 950 degrees centigrade.

7) A boiler arrangement as claimed in any preceding claim, wherein said heat source is a fossil fuel burner. 8) A boiler arrangement as claimed in any preceding claim, wherein said heating fluid comprises water drawn from a mains water supply.