WO2008067595A1

WO2008067595A1 - Method of heating and/or cooling

Info

Publication number: WO2008067595A1
Application number: PCT/AU2007/001867
Authority: WO
Inventors: Christopher Roderick Lomberg
Original assignee: Lomvac Technology Pty Ltd
Priority date: 2006-12-04
Filing date: 2007-12-03
Publication date: 2008-06-12

Abstract

A heat exchange assembly (11) comprising a flow path (20) having an inlet (16) and an outlet (18), the inlet (16) and outlet (18) adapted to be in fluid communication with a conduit (10) at respective spaced locations along the conduit (10), at least one portion of the flow path (20) associated with a heat exchanger (22) in heat exchange relationship with the flow path (20).

Description

"Method of Heating and/or Cooling"

Field of the Invention

The present invention relates to a method and apparatus related to the sourcing of or disposal of heat for in relation to an installation, which requires an exchange of heat. The installation can comprise a building or the heat exchanger of plant which may comprise a refrigeration system, air conditioning system, a heat pump or a like item of plant which requires an exchange of heat.

Background Art

The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

It is known to use external heat sinks or heat sources in conjunction with a heat exchanger to provide heating or cooling to a building or an installation. Examples include the use of geothermal heat as a heat source and the use of groundwater or surface water as a heat sink. Such heat sinks and sources use a closed loop which accommodates a heat exchange fluid which is caused to be in heat exchange relationship with a heat sink or source and in heat exchange relationship with the installation which is to be heated or cooled. Other arrangements comprise an open loop where a fluid which is to be heated or cooled is conducted through a heat source or sink to be heated or cooled. These arrangements are often constrained in practical application because of the availability of a suitable heat source or sink, the space required for the extensive piping required in the resultant horizontal and vertical closed loop systems, the number of bores required in vertical closed loops and the difficulties and cost in operating the extraction and re-injection bores in open loop systems.

The present invention attempts to overcome at least in part some of the aforementioned disadvantages of previous heat sink and source utilisation. Disclosure of the Invention

Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Throughout the specification and claims, unless the context requires otherwise the term "conduit" shall be taken as a pipe, conduit, duct or the like which is used to convey a fluid where the primary use of the fluid is for a purpose other than the purposes of heating or cooling and can include the fluid delivery system of a utility which is used to carry effluent, and waste water of all forms which can include sewerage, treated water, recycled waterj, or any fluid of an industrial installation and can also include transfer lines and any portion of a network of such conduits.

Throughout the specification and claims, unless the context requires otherwise the term "installation" shall be taken as a heat exchange facility associated with a building or plant which may include within its scope a refrigeration system, air conditioning system, a heat pump, or a processing facility which requires an exchange of heat as a part of its operation or a like item of plant which requires an exchange of heat.

In accordance with one aspect of the present invention there is provided a method of utilising a heat sink or a heat source, wherein the heat sink or heat source is a fluid carried in a conduit, the method comprising providing an inlet and an outlet in the wall of the conduit, the inlet being spaced along the conduit from the outlet, the inlet and outlet being interconnected by a flow path, at least one portion of the flow path being in heat exchange relationship with an installation, the method comprising extracting fluid from the conduit into the flow path via the inlet, causing the fluid to pass through the at least one portion of the flow path to enable an exchange of heat at the at least one portion and returning the fluid into the conduit through the outlet.

According to preferred feature of the invention the fluid is pumped through the flow path. According to a preferred feature of the invention a pressure differential is created in the conduit between the inlet and outlet and wherein the pressure differential causes the flow of fluid through the flow path.

According to a preferred feature of the invention the flow of fluid through the flow path is measured. According to one embodiment the quantity of fluid passing into and/or from the flow path is measured.

According to a preferred feature of the invention the quantity of heat delivered into or extracted from the contents of the conduit is measured.

According to another aspect the invention resides in a heat exchange assembly comprising a flow path having an inlet and an outlet, the inlet and outlet adapted to be in fluid communication with a conduit at respective spaced locations along the conduit, at least one portion of the flow path associated with a heat exchanger in heat exchange relationship with the flow path.

According to a preferred feature of the invention the assembly further comprises a pump which is adapted to induce a flow between the inlet and outlet.

According to preferred feature of the invention the assembly further comprises a bypass flow path interconnecting the inlet and outlet of the heat exchange means assembly which is not associated with the heat exchanger.

According to a preferred feature of the invention the bypass flow path is provided with a flow control means which is adapted to vary the flow rate through the bypass path.

According to a preferred feature of the invention the fluid is selectively allowed to flow through the flow path and/or the bypass flow path.

According to a preferred feature of the invention the apparatus further comprises a means of creating a pressure differential in the conduit between the inlet and outlet to induce a flow through the flow path between the inlet and outlet.

According to a preferred feature of the invention the apparatus further comprises a flow control means which is adapted to vary the flow rate through the flow path. According to an alternative feature of the invention the apparatus comprises a flow control means which is adapted to vary the flow rate through the bypass flow path and is adapted to vary the flow rate through the flow path.

According to a preferred feature of the invention the control means is adapted to vary the flow rates in accordance with the amount of heat which is to be absorbed or dissipated at the heat exchanger. According to a preferred feature of the invention the control means comprises sensors adapted to measure the flow rate of the fluid through the flow path. According to one embodiment the control means comprises a measuring means adapted to operate on the output of the sensors and provide measure of the quantity of fluid delivered to the flow path.

According to a preferred feature of the invention the conduit is associated with a sensing means and a measuring means adapted to determine the quantity of heat delivered into the conduit or extracted from the conduit by the apparatus. According to one embodiment the sensing means comprises a means for providing an output indicative of the temperature of the fluid flowing into the flow path, the temperature of the fluid flowing from the flow path and the flow rate of fluid through the flow path, the measuring means adapted to operate on the outputs from the sensing means to provide a measure quantity of the quantity of heat extracted from or delivered into the contents of the conduit.

According to a preferred feature of the invention the conduit comprises a sewer conduit and the fluid comprises the liquid effluent from that conduit in a treated or untreated state.

According to a preferred feature the inlet is associated with a separation means adapted to prevent at least large particulate or solid materials from entering the flow path. According to one embodiment the separating means comprises a screen. According to a preferred feature of the invention the separating means includes a settling zone. According to a preferred feature of the invention the separation means comprises a cyclonic separator.

According to a preferred feature of the invention the fluid passing through the flow path is liquid and the inlet is associated with a separation means further adapted to separate entrained gaseous fluids from the liquid entering the flow path. According to a further preferred feature of the invention the separator is further adapted to remove any dissolved gases which may effervesce from the fluid prior to the fluid entering the flow pathj and/or remove dissolved gases from the flow path which may effervesce from the fluid in its passage through the flow path.

The invention will be more fully understood in the light of the following description of several specific embodiments.

Brief Description of the Drawings

Preferred forms of the present invention will now be described with reference to the accompanying drawings, wherein:

Figure 1 is a schematic representation of a heat exchanger and heat sink or source according to the first embodiment; and

Figure 2 is a schematic representation of a heat exchanger and heat sink or source according to the fourth embodiment.

Detailed Description of Specific Embodiments

The first embodiment as shown in Figure 1 comprises a method of using a sewer conduit 10 for the purposes of dumping heat and the apparatus 11| according to the first embodiment is shown schematically in Figure 1.

In the case of the first embodiment the apparatus 11| according to the embodiment is associated with a conduit 10, having an external wall 12. The conduit 10 is pressurised such that the contents flow in one direction within the conduit from A to B in the drawing as shown by the arrows 14. It is anticipated that the conduit 10 is preferably located within the vicinity of the building (not shown) with which the apparatus of the embodiment is to be associated.

The apparatus 11 comprises an inlet 16, and an outlet 18 located in the external wall 12 of the conduit 10 at spaced intervals along the length of the conduit 10 with the outlet 18 being located downstream from the inlet 16. The apparatus 11 further comprises a flow path 20 which extends between the inlet 16 and the outlet 18 and as a result the flow path 20 is able to receive liquid from the conduit 10 at the inlet 16 and return the liquid to the conduit 10 at outlet 18 such that the liquid flows through the flow path 20 in the direction shown by arrows 21. To effect the flow of liquid through the flow path 20 a pump 24 is provided at the inlet 16 or the outlet 18 or at any position along the flow path 20.

The flow path 20 has a portion which is in heat exchange relationship with a heat exchanger 22 which is associated with an installation within a building such as an air conditioning plant having a closed circulation circuit 26 containing a heat exchange medium and a pump 28 for circulating the heat exchange medium through the circuit.

According to the embodiment heat is extracted from the heat exchange medium of the air conditioning plant by the heat exchanger 22 and is transmitted to the liquid within the flow path 20.

The pump 24 is controlled by a controller (not shown) which is associated with sensors which are associated with the heat exchanger 22 and/or the air conditioning plant such that the flow rate through the flow path 20 can be varied according to the quantity of heat which is to be extracted from the heat exchanger 22.

In addition the inlet 16 is associated with a screening or separating means (not shown) which is adapted to restrict the entry of solid materials into the flow path 20 which may be likely to cause a blockage within the flow path 20. The screening or separating means is such that any solid materials which are collected from the liquid entering the flow path 20 will not inhibit the continued flow of liquid into the flow path 20 but be returned to the sewer conduit 10 or extracted from the system.

According to the first embodiment liquid is drawn from the sewer conduit 10. The extracted liquid is screened to eliminate most solid materials whereby the screened material is returned to the sewer conduit 10 and the liquid is conveyed to the inlet 16 and is delivered to the heat exchanger 22. The liquid flowing from the portion of the flow path 20 associated with the heat exchanger 22 is then also delivered back into the sewer conduit 10 and in so doing delivers the heat which has been extracted from the heat exchanger 22 into the contents of the sewer conduit 10. The relative flow rates of the liquid flowing into the sewer iconduit 10 from the outlet 18 and the flow rate of liquid in the sewer conduit 10 between the inlet 16 and outlet 18 is able to be varied in order that the heat energy being delivered into the contents of the sewer conduit 10 will not result in a significant increase in temperature. In addition, the amount of heat delivered into the contents of the sewer conduit 10 may be governed by the inherent capacity of the conduit 10 to lose or use heat. It is anticipated that the added heat will be dissipated from the conduit 10 as a result of conduction through and from the walls of the conduit 10 or by digestion purposes.

It should be appreciated that the reference to an air conditioning plant in regard to the first embodiment is for illustrative purposes only and that the first embodiment can apply to any situation where excess heat must be dissipated. In addition the embodiment can have application to a circumstance where heat is required to an installation and the heat is extracted from the conduit 10.

According to a second embodiment the pump 24 of the first embodiment is replaced by a diversion means (not shown) located within the sewer conduit 10 which is able to induce a flow of liquid into the inlet 16. The diversion means for diverting the water may be a pressure reducing device located in the sewer conduit

10 between the inlet 16 and the outlet 18. One example of such a pressure reducing device is a section of conduit of reduced cross section compared with the conduit 10 upstream of the apparatus 11.

According to a third embodiment the flow through the flow path 20 may be effected as a result of an inherent pressure difference in the sewer conduit 10 between the inlet 16 and the outlet 18. One example of when this may occur is when the flow rate down the conduit 10 is high and the frictional losses within the conduit 10 create a pressure differential in the length of the conduit 10 between the inlet 16 and the outlet 18.

A fourth embodiment is shown in figure 2 which has some similar features to the preceding embodiments] and therefore, the same numbers are used to indicate similar corresponding components.

According to the fourth embodiment a bypass flow path 32 is connected between the inlet 16 and outlet 18. The bypass flow path 32 has a flow control means 36 which in this embodiment is a valve 36. The valve 36 can be selectively adjusted between a fully open position and a fully closed position as well as intermediate positions there between. Reducing the opening of the valve 36 reduces the flow through the bypass flow path 32 and conversely, increasing the opening of the valve 36 increases the flow through the bypass flow path 32. By closing or reducing the opening of the valve 36 the flow rate in the bypass fluid path 32 is decreased and thereby the flow rate through the heat exchanger 22 is increased with a corresponding increase in the transfer of heat. By opening or increasing the opening of the valve 36 the flow rate in the bypass fluid path 32 is increased and thereby the flow rate through the heat exchanger 22 is reduced with a corresponding decrease in the transfer of heat.

The opening and closing of the valve 36 is controlled by a controller 34 which in this embodiment is a Programmable Logic Control device. The controller 34 receives signals from sensors 38 associated with the heat exchanger 22 and/or the air conditioning plant. The sensors 38 can be adapted to measure the flow rate of the fluid through the flow path 32. Thus the flow rate through the bypass flow path 32 can be varied according to the quantity of heat which is to be transferred through the heat exchanger 22. The controller 34 can also include a measuring means adapted to operate on the output of the sensors 38 to provide a measure of the quantity of fluid delivered to the flow path 32.

The sensors 38 can also comprise a means for providing an output indicative of the temperature of the fluid flowing into the flow path 32, the temperature of the fluid flowing from the flow path 32 and the flow rate of fluid through the flow path 32. The controller 34 can then be adapted to operate on the outputs from the sensors 38 to provide a measure of the quantity of heat extracted from or delivered into the contents of the conduit 10.

In an alternative embodiment the controller 34 can control the valve 36 of the bypass flow path 32 and also control the pump 24 such that the flow rate through the flow path 20 can be varied according to the quantity of heat which is to be transferred through the heat exchanger 22.

According to further alternative embodiments each of the above embodiments can be applied to use in association with other fluid conveying systems and in particular can be used with conduits carrying recycled waters, waste waters including sewers, potable water or natural gas and like gaseous mediums. In addition the embodiments can have application to fluid flow lines which are used in industrial plants and the like for the conduct of fluids such as gases, liquids, potable water, slurries, waste water, effluents and the like whereby heat can be extracted from an installation and delivered into the conduit.

According to further alternative embodiments, in each of the above embodiments the apparatus may be used for extracting heat from the flow line and delivering that heat to an installation.

In addition while each of the embodiments have been described with the inlet being upstream from the outlet this has been more for the sake of clarity since in many reticulated fluid systems the fluid within the conduit can flow in both directions along the conduit depending on the nature of the reticulation system and the drawing demands being made on the system at any one time.

Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. For example, the separating means for removing large particulates from the fluid can alternatively include a settling zone or a cyclonic separator. The separation means can also be further adapted to separate entrained gaseous fluids from the liquid prior to entering the flow path, or remove dissolved gases from the flow path which may effervesce from the fluid in its passage through the flow path.

Claims

The Claims Defining the Invention is as Follows:

1. A method of utilising a heat sink or a heat source, wherein the heat sink or heat source is a fluid carried in a conduit, the method comprising providing an inlet and an outlet in the wall of the conduit, the inlet being spaced along the conduit from the outlet, the inlet and outlet being interconnected by a flow path, at least one portion of the flow path being in heat exchange relationship with an installation, the method comprising extracting fluid from the conduit into the flow path via the inlet, causing the fluid to pass through the at least one portion of the flow path to enable an exchange of heat at the at least one portion and returning the fluid into the conduit through the outlet.

2. The method of claim 1 wherein the fluid is pumped through the flow path.

3. The method of claim 1 wherein a pressure differential is created in the conduit between the inlet and outlet and wherein the pressure differential causes the flow of fluid through the flow path.

4. The method of any one of the preceding claims wherein the flow of fluid through the flow path is measured.

5. The method of any one of the preceding claims wherein the quantity of fluid passing into and/or from the flow path is measured.

6. The method of any one of the preceding claims wherein the quantity of heat delivered into or extracted from the contents of the conduit is measured.

7. A heat exchange assembly comprising a flow path having an inlet and an outlet, the inlet and outlet adapted to be in fluid communication with a conduit at respective spaced locations along the conduit, at least one portion of the flow path associated with a heat exchanger in heat exchange relationship with the flow path.

8. The assembly of claim 7 further comprising a pump which is adapted to induce a flow into the flow path between the inlet and outlet.

9. The assembly of claim 7 or 8 further comprising a bypass path interconnecting the inlet and outlet of the heat exchange assembly which is not associated with the heat exchanger.

10. The assembly of claim 9 wherein the bypass path is provided with a flow control means which is adapted to vary the flow rate through the bypass path.

11. The assembly of claim 9 or 10 wherein fluid is selectively allowed to flow through the flow path and/or the bypass path.

12. The assembly of claim 9 further comprising a means of creating a pressure differential in the conduit between the inlet and outlet to induce a flow through the flow path between the inlet and outlet.

13. The assembly of any one of claims 7 to 12 further comprising a flow control means which is adapted to vary the flow rate through the flow path.

14. The assembly of claim 8 further comprising a flow control means which is adapted to vary the flow rate through the bypass path and the flow path.

15. The assembly of claim 14 wherein the control means is adapted to vary the flow rates in accordance with the amount of heat which is to be absorbed or dissipated at the heat exchanger.

16. The assembly of claim 14 or 15 wherein the control means comprises sensors adapted to measure the flow rate of the fluid through the flow path.

17. The assembly of claim 16 wherein the control means further comprises a measuring means adapted to operate on the output of the sensors and provide measure of the quantity of fluid delivered to the flow path.

18. The assembly of claim 16 or 17 wherein the conduit is associated with a sensing means and a measuring means adapted to determine the quantity of heat delivered into the conduit or extracted from the conduit by the assembly.

19. The assembly of claim 18 wherein the sensing means comprises a means for providing an output indicative of the temperature of the fluid flowing into the flow path, the temperature of the fluid flowing from the flow path and the flow rate of fluid through the flow path, the measuring means adapted to operate on the outputs from the sensing means to provide a measure of the quantity of heat extracted from or delivered into the contents of the conduit.

20. The assembly of claim 14 wherein the conduit comprises a sewer conduit and the fluid comprises the liquid effluent from that conduit in a treated or untreated state.

21. The assembly of claim 20 wherein the inlet is associated with a separation means adapted to prevent at least large particulate or solid materials from entering the flow path.

22. The assembly of claim 21 wherein the separating means comprises a screen.

23. The assembly of claim 21 wherein the separating means includes a settling zone.

24. The assembly of claim 21 wherein the separation means comprises a cyclonic separator.

25. The assembly of claim 20 wherein the fluid passing through the flow path is liquid and the inlet is associated with a separation means further adapted to separate entrained gaseous fluids from the liquid entering the flow path.

26. The assembly of claim 25 wherein the separator is further adapted to remove any dissolved gases which may effervesce from the fluid prior to the fluid entering the flow path.j and/or remove dissolved gases from the flow path which may effervesce from the fluid in its passage through the flow path.

27. A method of utilising a heat sink or a heat source, the method substantially as herein described with reference to Figure 1 or Figure 2 of the accompanying drawings.

28. A heat exchange assembly substantially as herein described with reference to Figure 1 or Figure 2 of the accompanying drawings.