GB2447670A

GB2447670A - Heat transfer in void beneath building

Info

Publication number: GB2447670A
Application number: GB0705332A
Authority: GB
Inventors: Roger Bullivant
Original assignee: Roxbury Ltd
Current assignee: Roxbury Ltd
Priority date: 2007-03-21
Filing date: 2007-03-21
Publication date: 2008-09-24
Also published as: GB0705332D0

Abstract

A heat exchanger is provided in a void 22 between the lowermost floor 12 of a building 24 and the ground 20 for heat exchange between the interior 28 and exterior 29 of the building 24. The first heat exchanger may comprise refrigerant-filled legs 38 within the void 22 and may be connected to 'C'-shaped, metal radiating members 14, which may form the floor supports. The heat exchanger 38 may be embedded in a material with high thermal conductivity 46 within a recess 44 of the radiating member 14. A second heat exchanger 32, a compressor 34 and expansion device 36 may be provided to form a refrigeration circuit 26 operable to either heat or cool the interior 28. A second circuit 48 may be provided for heat recovery or storage, e.g. to heat water 50. Legs 60 may extend into the ground 20 for geothermal heat exchange and may form part of the refrigerant circuit (figure 5), or a separate circuit. A wind-blown cowl 70, or fan or blower may be provided within the void 22 to drive a turbine to draw air through duct 66 to ventilate the void 22 (figure 7) and the expansion device 36 may include a turbine to drive a generator (72, figure 7) to provide electricity.

Description

lmrovements in or Relating to Heating and/or Coollnci of Buildings The

present invention relates to arrangements for heating and/or cooling buildings.

Embodiments of the present invention provide a building comprising a lowermost floor supported above the ground to provide a void beneath the building, and a heat transfer arrangement operable to transfer heat between the interior and exterior of the building, the heat transfer arrangement including a first heat exchanger located within the void.

The heat transfer arrangement may include a second heat exchanger located in the interior of the building, the heat transfer arrangement providing a refrigeration system for transferring heat through the heat exchangers, between the interior and exterior the building.

The first heat exchanger may include a pipe containing refrigerant and having a leg extending within the void. There may be a plurality of legs extending within the void. At least one of the pipe legs may be affixed to a radiating member within the void. The radiating member may be a metal member. The or each pipe leg may be affixed to an elongate supporting member on which the floor is supported. The elongate member may be metal to provide improved thermal contact between the pipe leg and the void. The elongate member may be a channel section. The pipe leg may be housed within a recess in the channel member. The pipe leg may be embedded within a body of material which provides enhanced thermal contact between the pipe leg and the elongate supporting member.

The first heat exchanger may include a pipe containing refrigerant and having a leg which extends into the ground, for geothermal heat exchange.

The pipe may form part of a refrigerator circuit which extends into the interior of the building. The geothermal leg may form part of a thermal circuit which includes the first heat exchanger and the ground, and is external to the building. The pipe for geothermal heat exchange may form part of a refrigerant circuit which is separate from the said refrigeration system.

The heat transfer arrangement may include a heat exchange arrangement for diverting heat being transferred between the interior and exterior, the diverted heat being stored. The diverted heat may be stored for water heating.

The heat transfer arrangement may include a first circuit for heat transfer between the interior and exterior of the building, a second circuit for diverted heat, and at least one heat exchanger coupling the circuits. There may be at least one coupling heat exchanger within the building and at least one coupling heat exchanger outside the building. The first heat exchanger may provide the outside coupling heat exchanger. The coupling heat exchangers may be in respective legs of the second circuit, there being switch means operable to connect the legs into or out of the second circuit.

The refrigeration system may include a compressor and an expansion device. The expansion device may include a turbine operable to extract energy from the refrigerant, as it expands.

The second heat exchanger may be embedded within a floor of the building. There may be ducting for conveying air past the first heat exchanger when travelling between the interior and exterior of the building.

Embodiments of the present invention will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which: Fig. I is a schematic perspective view of a floor structure of a building with which embodiments of the present invention may be used: Fig. IA isa cross-section of a beam used in the floor of Fig. 1; Fig. 2 is a schematic diagram of a first embodiment of the invention; Fig. 3 corresponds with Fig. 2 and illustrates additional features of a modified embodiment; Fig. 4 illustrates further modifications of the embodiment of Fig. 2; Fig. 5 illustrates modifications of the arrangement of Fig. 3, with geothermal heat exchange; Fig. 6 represents a modified version of the arrangement of Fig. 5; and Fig. 7 is a schematic diagram of a further embodiment.

Embodiments of the present invention provide a building comprising a lowermost floor supported above the ground to provide a void beneath the building.

Fig. 1 illustrates a floor construction 10, which is an example of a floor construction for such a building. The floor construction 10 consists of a floor slab 12, which may be poured, settable material, or sheet material, or the like.

The slab 12 is supported by parallel beams 14. In this example, the beams 14 are metal beams of generally C-shape section, as illustrated more clearly in Fig. 1A. The spanning beams 14 are supported at each end by peripheral beams 16, at the edges of the building. Additional beams 16 may be provided at other positions across the building, according to the length of the beams 14. The beams 16 are in turn supported, for example by piles 18 in the ground 20. Alternatively, the beams 16 may be laid directly on the ground 20.

The beams 14, 16 serve to support the floor 12 above the ground 20, so that a void 22 exists above the ground 20 and below the floor 12, between the beams 14, 16. Accordingly, the void 22 is beneath the building of which the floor 12 forms part.

Fig. 2 illustrates a first example of an embodiment of the invention. In this example, a building 24 includes a lowermost floor 12 of the type described above in relation to Fig. 1. The floor 12 is supported above the ground 20 to provide a void 22 beneath the building 24. A heat transfer arrangement indicated generally as a circuit 26 is provided to transfer heat between the interior 28 and exterior 29 of the building 24. The heat transfer arrangement 26 includes a first heat exchanger located within the void 22.

In addition to the first heat exchanger 30, the heat transfer arrangement 26 includes a second heat exchanger 32 located in the interior 28 of the building 24. The heat transfer arrangement 26 is a circuit for circulating refrigerant material through the first and second heat exchangers 30, 32, there being a compressor 34 and expansion device 36 to create a refrigeration system for transfemng heat through the heat exchangers 30, 32, between the interior 28 and exterior of the building, the exterior being represented by the void 22. It is important to note that the direction of heat transfer between the interior 28 and exterior 22 can be in either direction, according to the direction in which refrigerant circulates around the circuit 26.

The compressor 34 serves to supply one of the heat exchangers 30, 32 with pressurised refrigerant, the supplied heat exchanger becoming the hot side of the circuit 26. Refrigerant then passes through the expansion device 36 to the other exchanger 32, 30 respectively, forming the cold side of the circuit 26.

Preferably, the compressor 34 and expansion device 36 are constructed or connected to operate in either direction, so that the interior 28 can be cooled or warmed.

One leg 38 of the pipe 40 containing the refrigerant of the circuit 26 extends within the void 22. This pipe leg 40 is affixed to one of the metal beams 14 on which the floor 12 is supported. Affixing the pipe leg 38 to the beam 14 places the pipe leg 38 and the beam 14 in thermal contact. The metal material of the beam 14 causes the beam 14 to act as a heat sink or radiator fin, providing improved thermal contact between the pipe leg 38 and the void 22. This thermal contact is further enhanced in the manner illustrated in Fig. IA. The base 42 of the C-channel of the beam 14 is provided with an elongate recess 44 in which the leg 38 is housed, embedded within a body 46 of material which provides enhanced heat transfer characteristics between the leg 38 and the beam 14. The body 46 may be of a graphite based filler material, for example.

The pipe leg 38, together with the beam 14, provide a heat exchanger for heat exchange between the refrigerant of the circuit 26, and the void 22.

The size, and therefore the thermal efficiency of the heat exchanger 30 can be further improved by providing additional legs 38 of the circuit 26, which may be affixed to respective beams 14. The set of legs 38 and beams 14 then form a radiator structure which may extend over the whole floor area of the building 24. Indeed, the total surface area available for heat exchange, that is, the exposed surface area of the beams 14, may equal or exceed the floor area of the building, depending on the dimensions and spacing of the beams 14.

In use, the circuit 26 can be used to cool or heat the interior 28. When heating the interior 28, the compressor 34 draws refrigerant from the first heat exchanger 30, compresses it and supplies it to the second heat exchanger 30, which then gives off heat to the interior 28. The refrigerant then expands in the device 36 before returning to the first heat exchanger 30, now at low temperature to draw energy from within the void 22.

Alternatively, the interior 28 may be cooled by reversing the direction of flow of the refrigerant, so that refrigerant leaving the first heat exchanger 30 expands within the device 36 to be relatively cold within the second heat exchanger 32, thereby cooling the interior 28. The refrigerant is then compressed by the compressor 34 before returning to the first heat exchanger 30, now relatively hot, to lose heat to the void 22.

The efficiency of heat exchange with the void 22 is expected to be very large, by virtue of the large size of the first heat exchanger 30, as has been described.

Fig. 3 illustrates a modified version of the embodiment of Fig. 2. The reference numerals of Fig. 2 are used again in Fig. 3, for corresponding features. The arrangement of Fig. 2 includes the heat transfer arrangement 26 operating as described above, to heat or cool the interior 28. In addition, a second circuit 48 is provided for energy recovery and storage. In this example, recovered energy is used to heat water stored in a tank 50, which may be used as the hot water supply for the building 24. The circuit 48 has three legs. A first leg 48a extends through the tank 50 and includes a pump 52. A medium, such as water, heated as will be described, passes along the leg 48a to heat the contents of the hot water tank 50. The leg 48a is connected either to the leg 48b or to the leg 48c by valves 54. The leg 48b includes a coupling heat exchanger 56a in thermal contact with the circuit 26 to allow heat to be diverted from the circuit 26, when the second heat exchanger is the hot side of the circuit 26. Thus, when the pump 52 is circulating medium through the circuit consisting of the legs 48a and 48b, heat being used to heat the interior 28 can be diverted through the coupling heat exchanger 56a to heat the contents of the water tank 50.

The leg 48c of the circuit 48 extends into the void 22 and is affixed to one or more of the beams 14 in the manner described above in relation to the circuit 26. Accordingly, the leg 48c is in thermal contact with the first heat exchanger 30, forming a coupling heat exchanger 56b. When the circuit 26 is being used to cool the interior 28, so that the first heat exchanger 30 is the hot side of the circuit 26, heat being given off to the void 22 can be diverted through the leg 48c to heat the contents of the water tank 50.

Fig. 4 illustrates a further modification of the arrangement of Fig. 3.

Numerals from previous figures are used again, for corresponding features.

In the arrangement of Fig. 4, the arrangement of Fig. 3 is further modified by extending the legs 48b, 48c of the circuit 48. Thus, the leg 48, which diverts heat from the second heat exchanger 32 when used as the hot side, also has an additional leg 48e which extends to a heat exchanger 58a, between the cold side heat exchanger (the first heat exchanger 30) and the compressor 34. Similarly, the leg 48c has an additional leg 48f extending to a heat exchanger 58b between the second heat exchanger 32 and the compressor 34, noting that when the leg 48c is being used, the first heat exchanger 30 is the hot side of the circuit 26.

The use of the additional legs 48e, 48f and heat exchangers 58a, 58b allows additional heat to be recovered for diversion to heat the contents of the water tank 50.

Fig. 5 illustrates a further example which has many similarities with the example of Fig. 3. Accordingly, corresponding features are given the same reference numerals.

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In the example of Fig. 5, the construction of the first heat exchanger 30 is more complex than in the example of Fig. 3. In common with the example of Fig. 3, the first heat exchanger 30 has a first leg 38 affixed to a beam 14 (and may have additional legs 38 affixed to additional beams 14, to create a very large radiator, in the manner which has been described). In addition to the leg or legs 38, the circuit 26 extends down into the ground 20, below the void 22. In this example, the circuit 26 has several legs 60 which are embedded within the ground 20. Thus, the refrigerant of the circuit 26 is able to undertake geothermal heat exchange within the legs 60. Thus, in this example, the geothermal legs 60 form part of the refrigeration circuit 26 which extends into the interior 28 of the building 24. The circuit 26 includes the leg 38 of the first heat exchanger 30, and the geothermal circuit provided by the legs 60.

In the example of Fig. 5, the refrigerant flowing around the circuit 26 therefore flows through the geothermal legs 60 and thus, flows through the ground 20. In some circumstances, this may be considered undesirable, for example because corrosion of the pipes in the legs 60 may result in refrigerant being released into the ground 20, creatIng ground pollution. This difficulty is addressed by the further modification illustrated in the example of Fig. 6. This has many similarities with the example of Fig. 5 and therefore, the same reference numerals are used again.

The example of Fig. 6 differs from the example of Fig. 5 in that the circuit 26 is separated from the geothermal circuit. Thus, the circuit 26 is formed in the manner of the example of Fig. 3, with the leg 38 forming part of the first heat exchanger 30 by being affixed to a beam 14. A geothermal circuit 62 has a leg 62a running along the beam 14, preferably within the recess 44 in the beam 14, to be in good thermal contact with the beam 14 and the leg 38. The circuit 62 also includes geothermal legs 62b embedded in the ground 20, in the manner of the legs 60 of the example of Fig. 5. The legs

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62a, 62b form a closed circuit around which a heat transfer medium is pumped by a pump 64. The medium is preferably water, so that the pollution risk, described above, is removed.

Accordingly, it can be seen that in the example of Fig. 5, the first heat exchanger 30 includes the leg 38 and beams 14, allowing heat to be given off to or drawn from the void 22, and also includes the geothermal legs 60, allowing heat exchange with the ground 20. By contrast, in the example of Fig. 6, the first heat exchanger 30 provides for heat exchange between the circuit 26 and the void 22, by means of the leg 38 and the beam 14, and also allows for heat exchange between the circuit 26 and the geothermal circuit 62.

The geothermal circuit 62 then provides for heat exchange with the ground 20.

In both of the examples of Figs. 5 and 6, the hot water circuit described more fully in relation to Fig. 3 may be optionally included and may optionally include the enhancements described above in relation to Fig. 4.

In all of the examples described above, it is desirable for the void 22 to be well ventilated to the surrounding atmosphere, to improve the thermal efficiency achieved. Fig. 7 illustrates one possibility for achieving enhanced ventilation of the void 22, using active ventilation. In this example, many features are common with previous examples, but illustrated in less detail.

Nevertheless, they are given the same reference numerals.

In the example of Fig. 7, the first heat exchanger 30, in the void 22, is located in a duct having an inlet 66, close to ground level, and an outlet 68, illustrated in this example as being at roof level. The outlet 68 has a wind-blown rotating cowl 70 driving a turbine to draw ventilation air through the duct, past the heat exchanger 30. The heat exchanger forms part of the circuit 26, allowing heat transfer between the interior 28 and the exterior air flowing through the duct, in the manner which has been described.

In the example of Fig. 7, the second heat exchanger 32 is illustrated as embedded in the floor 12, for example to provide under floor heating or cooling.

Accordingly, it can be seen that in Fig. 7, the floor 12 is supported above the ground 20, leaving a void 22 in which the first heat exchanger 30 is accommodated to enable heat transfer between the interior 28 and the exterior of the building 24.

The example of Fig. 7 includes a further modification which can be used in conjunction with any of the other examples described above. In this example, the expansion device 36 is not a simple expansion valve common to many conventional refrigeration circuits, but is an expansion device which incorporates a turbine which can extract energy from the refrigerant, as it expands. This is used to drive a generator 72, to provide electrical energy for the building 24, recovered from the circuit 26.

Any of the preceding examples may be modified to incorporate the heat exchange and duct arrangements of the example of Fig. 7, or to incorporate the expansion device 36 of the example of Fig. 7. The example of Fig. 7 may be modified by providing for the duct to draw air from the interior 28, particularly from hot rooms such as a kitchen or bathroom, so that ventilation is provided while allowing heat to be recovered by the first heat exchanger 30.

Ventilation through the void 22 (including ventilation through the duct) may be entirely passive, wind driven as illustrated in the example of Fig. 7, or driven by powered fans, blowers etc. Many variations and modifications can be made to the apparatus described above, without departing from the scope of the present invention.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A building comprising a lowermost floor supported above the ground to provide a void beneath the building, and a heat transfer arrangement operable to transfer heat between the interior and exterior of the building, the heat transfer arrangement including a first heat exchanger located within the void.

2. A building according to claim 1, wherein the heat transfer arrangement includes a second heat exchanger located in the interior of the building, the heat transfer arrangement providing a refrigeration system for transferring heat through the heat exchangers, between the interior and exterior the building: 3. A building according to claim 1 or 2, wherein the first heat exchanger includes a pipe containing refrigerant and having a leg extending within the void.

4. A building according to claim 3, wherein there are a plurality of legs extending within the void.

5. A building according to claim 3 or 4, wherein at least one of the pipe legs is affixed to a radiating member within the void.

6. A building according to claim 5, wherein the radiating member is a metal member.

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* 7. A building according to any of claims 3 to 6, wherein the or each pipe *..*S * leg is affixed to an elongate supporting member on which the floor is *:* 30 supported. S. S * * *S

8. A building according to claim 7, wherein the elongate member is metal to provide improved thermal contact between the pipe leg and the void.

9. A building according to claim 7 or 8, wherein the elongate member is a channel section.

10. A building according to claim 9, wherein the pipe leg is housed within a recess in the channel member.

11. A building according to any of claims 7 to 10, wherein the pipe leg is embedded within a body of material which provides enhanced thermal contact between the pipe leg and the elongate supporting member.

12. A building according to any preceding claim, wherein the first heat exchanger includes a pipe containing refrigerant and having a leg which extends into the ground, for geothermal heat exchange.

13. A building according to claim 12, wherein the pipe forms part of a refrigerator circuit which extends into the interior of the building.

14. A building according to claim 12 or 13, wherein the geothermal leg forms part of a thermal circuit which includes the first heat exchanger and the ground, and is external to the building. * 25 *.

A building according to claim 12, 13 or 14, wherein the pipe for geothermal heat exchange forms part of a refrigerant circuit which is separate from the said refrigeration system.

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30 16. A building according to any preceding claim, wherein the heat transfer arrangement includes a heat exchange arrangement for diverting heat being transferred between the interior and exterior, the diverted heat being stored.

17. A building according to claim 16, wherein the diverted heat is stored for water heating.

18. A building according to any preceding claim, wherein the heat transfer arrangement includes a first circuit for heat transfer between the interior and exterior of the building, a second circuit for diverted heat, and at least one heat exchanger coupling the circuits.

19. A building according to claim 18, comprising at least one coupling heat exchanger within the building and at least one coupling heat exchanger outside the building.

20. A building according to claim 19, wherein the first heat exchanger provides the outside coupling heat exchanger.

21. A building according to any of claims 18 to 20, wherein the coupling heat exchangers are in respective legs of the second circuit, there being switch means operable to connect the legs into or out of the second circuit.

22. A building according to claim 2 or any of claims 3 to 21 insofar as dependent on claim 2, wherein the refrigeration.system includes a compressor and an expansion device.

25 23. A building according to claim 22, wherein the expansion device *.** includes a turbine operable to extract energy from the refrigerant, as it expands. **S

* 24. A building according to claim 2, 22, 23 or any of claims 3 to 21 insofar 30 as dependent on claim 2, wherein the second heat exchanger is embedded within a floor of the building.

25. A building according to any preceding claim, comprising ducting for conveying air past the first heat exchanger when travelling between the interior and exterior of the building.

26. A building substantially as described above, with reference to the accompanying drawings.

27. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims. p. p. p *IS * S.. I *

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