Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
METHOD AND SYSTEM OF RAPID HEATING AND COOLING OF A FLUID
Document Type and Number:
WIPO Patent Application WO/2016/025985
Kind Code:
A1
Abstract:
A system (10) for rapidly changing the temperature of a fluid between an inlet (14) and an outlet (16), the system (10) including a heat exchanger unit (36) connected between the inlet (14) and the outlet (16) and having a first member (52) interleaved with a second member (60) such that a passageway (84) is defined between the first (52) and second (60) members for the fluid to flow through; thermoelectric means (22) linked to one or both the first and second members (52, 60) for altering the temperature of the fluid; a source of electrical energy (20) connected to the thermoelectric means (22); control means (18) linked to the thermoelectric means (22); a first temperature sensor (26) for measuring the temperature of the fluid input to the heat exchanger unit at the inlet (14); a second temperature sensor (28) for measuring the temperature of the fluid output from the heat exchanger unit (36) at the outlet (16);wherein said control means (18) controls the amount of energy drawn by the thermoelectric means (22) to change the temperature of the fluid to match a predetermined temperature difference At of the fluid between the inlet (14) and the outlet (16) or the temperature of the fluid at the outlet (16) based on signals received from each of the first and second temperature sensors (26, 28).

Inventors:
VAN AKEN, Robert Cornelis (72/503 Orrong Road, Armadale, VIC 3143, AU)
DOBSON, Nicholas James (9 Kinsale Crescent, Mont Albert North, VIC 3129, AU)
Application Number:
AU2015/000497
Publication Date:
February 25, 2016
Filing Date:
August 19, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
VAND TECHNOLOGY PTY LTD (CI- The Practice, Level 10 369 Royal Parad, Parkville VIC 3052, AU)
International Classes:
F28D20/00; B60H1/00; F25B21/02; F28D21/00; H01L35/00; H01L37/00
Foreign References:
US5711155A1998-01-27
KR20100029572A2010-03-17
US20120312030A12012-12-13
US20120279233A12012-11-08
Attorney, Agent or Firm:
OLLERENSHAW, Richard E (Patent Attorney Services, 26 Ellingworth ParadeBox Hill, VIC 3128, AU)
Download PDF:
Claims:
CLAIMS:

1. A system for rapidly changing the temperature of a fluid between an inlet and an outlet, said system including: a heat exchanger unit connected between the inlet and the outlet and having a first member interleaved with a second member such that a passageway is defined between the first and second members for the fluid to flow through; thermoelectric means linked to one or both the first and second members for altering the temperature of the fluid; a source of electrical energy connected to the thermoelectric means ; control means linked to the thermoelectric means; a first temperature sensor for measuring the temperature of the fluid input to the heat exchanger unit at the inlet; a second temperature sensor for measuring the temperature of the fluid output from the heat exchanger unit at the outlet; wherein said control means controls the amount of energy drawn by the thermoelectric means to change the temperature of the fluid to match a predetermined temperature difference At of the fluid between the inlet and the outlet or the temperature of the fluid at the outlet based on signals received from each of the first and second temperature sensors.

2. A system according to claim 1 further including flow sensor means positioned at or near the outlet for measuring the flow of fluid leaving the outlet.

3. A system according to claim 1 or claim 2 wherein the control means receives signals from any one or more of the first temperature sensor, the second temperature sensor or the flow sensor means, said signals representative of temperature of the fluid or flow rate of the fluid.

4. A system according to claim 3 wherein the control means has a memory device and a processor device, said memory device storing values associated with said predetermined

c

Substitute Sheet

(Rule 26) RO/AU temperature difference At and tout where tout the is the set temperature at the outlet, said processor device receiving said signals representative of temperature of the fluid or flow rate of the fluid.

5. A system according to claim 4 wherein said processor device compares the received signals to the predetermined At and tout stored in said memory device.

6. A system according to claim 5 wherein the control means has switch means connected to said thermoelectric means and to said processor device, such that when the value or values of the measured At and tout from the received signals differ from the predetermined At and tout , the processor device controls the switch means to enable said thermoelectric means to receive energy from the electrical energy source.

7. A system according to claim 6 wherein said thermoelectric means includes one or more thermoelectric devices.

8. A system according to any one of the preceding claims wherein the heat exchanger unit includes a frame for housing said first and second members and a pair of heat sinks mounted at respective sides of the heat exchanger unit.

9. A system according to claim 8 wherein the first member and the second member form part of a heat exchanger in the heat exchanger unit, said first member connected to said thermoelectric means by a first plate member and said second member connected to said thermoelectric means by a second plate member, each of said first and second plate members adapted to transfer energy from said thermoelectric means to said first and second members of the heat exchanger.

10. A system according to claim 9 wherein said first member includes a first set of substantially parallel fins and said second member includes a second set of substantially parallel fins, said second set of substantially parallel fins being interleaved with respective fins in said

Substitufe Sheet

(Rule 26) RO/AU first set of fins so as to define said passageway for fluid to flow through, the passagewa including multiple channel sections with each channel section defined between a fin of the first set of fins and a fin of the second set of fins.

1 1. A system according to claim 10 wherein said thermoelectric means includes one or more thermoelectric devices with each said one or more thermoelectric devices connected to said source of electrical energy.

12. A system according to claim 10 or claim 1 1 wherein the arrangement of the first and second sets of fins in said frame is such that a reservoir is formed at an end of each fin in either or both sets of fins for the fluid to temporarily reside in.

13. A system according to claim 12 wherein the flow of fluid through the heat exchanger is laminar, which together with the reservoir at the end of each fin creates a vortex effect in the fluid that mixes the fluid to attain a substantially equal temperature in the channel sections of the passageway, which improves the thermal transfer of energy from the fins of the heat exchanger to the fluid.

14. A system according to any one of the previous claims wherein the fluid is heated through said thermoelectric means.

15. A system according to any one of claims 1 to 13 wherein the fluid is cooled through said thermoelectric means by reversing the direction of current supplied from the electrical energy source through the thermoelectric means.

16. A system according to any one of claims 8 to 13 wherein the heat exchanger unit has a fan unit and a pair of side panels that attach to the fan unit, each side panel having an inwardly diverging channel such that a gap is formed between the channels through which air is blown under pressure from the fan unit to cool the heat sinks.

Substitute Sheet

(Rule 26) RO/AU

17. A method of rapidly changing the temperature of a fluid between an inlet and an outlet in a system having a heat exchanger unit connected between the inlet and the outlet and

thermoelectric means linked to the heat exchanger unit, the heat exchanger unit having a first member interleaved with a second member such that a passageway is defined between the first and second members for the fluid to flow through, said method including: measuring the temperature of the fluid input to the heat exchanger unit at the inlet; measuring the temperature of the fluid output to the heat exchanger unit at the outlet; controlling the amount of energy drawn by said thermoelectric means to change the temperature of the fluid in response to the measured temperatures at the inlet and the outlet; stopping the provision of energy to said thermoelectric means when the difference in temperature of the fluid between the inlet and the outlet matches a predetermined fluid temperature difference At or a predetermined outlet fluid temperature has been reached.

18. A method according to claim 17 including providing said first member with a first set of substantially parallel fins and providing said second member with a second set of substantially parallel fins, said second set of substantially parallel fins being interleaved with respective fins in said first set of fins so as to define said passageway for fluid to flow through, the passageway including multiple channel sections with each channel section defined between a fin of the first set of fins and a fin of the second set of fins.

19. A method according to claim 18 including forming a reservoir at an end of each fin in either or both of the first set of fins or the second set of fins in which the fluid temporarily resides.

20. A method according to claim 19 wherein the flow of fluid through the heat exchanger is laminar, which together with the reservoir at the end of each fin forms a vortex effect in the fluid that mixes the fluid to attain a substantially equal temperature in the channel sections of the

Substitute Sheet

(Rule 26) RO/AU passageway to improve the thermal transfer of energy from the fins of the heat exchanger to the fluid.

21. A heat exchanger for use in a system for rapidly changing the temperature of a fluid between an inlet and an outlet; including: a first member and a second member interleaved between one another and defining a passageway for fluid to flow therethrough, said fluid flowing from the inlet to the outlet; means for heating or cooling either one or both the first and second members and connected to said first and second members; wherein the temperature of the fluid at the inlet and the outlet is measured and if the temperature difference between the fluid at the inlet and at the outlet is not equivalent to a predetermined temperature difference At or the outlet temperature is not equivalent to a predetermined outlet fluid temperature, then energy is provided to said means for heating or cooling to heat or cool the fluid until the temperature difference between the fluid at the inlet and at the outlet matches said predetermined temperature difference At or until the predetermined outlet fluid temperature has been reached.

22. A heat exchanger according to claim 21 wherein said means for heating or cooling includes one or more thermoelectric devices with each said one or more thermoelectric devices connected to a source of electrical energy.

23. A heat exchanger according to claim 21 or claim 22 wherein said first member is connected to said means for heating or cooling by a first plate member and said second member is connected to said means for heating or cooling by a second plate member, each of said first and second plate members adapted to transfer energy from said means for heating or cooling to said first and second members of the heat exchanger.

24. A heat exchanger according to any one of claims 21 to 23 wherein said first member includes a first set of substantially parallel fins and said second member includes a second set of in

Substitute Sheet

(Rule 26) RO/AU substantially parallel fins, said second set of substantially parallel fins being interleaved with respective fins in said first set of fins so as to define said passageway for fluid to flow through, the passageway including multiple channel sections with each channel section defined between a fin of the first set of fins and a fin of the second set of fins.

25. A heat exchanger according to claim 24 wherein the arrangement of the first and second sets of fins in said frame is such that a reservoir is formed at an end of each fin in either or both sets of fins for the fluid to temporarily reside in.

26. A heat exchanger to claim 25 wherein the flow of fluid through the heat exchanger is laminar, which together with the reservoir at the end of each fin creates a vortex effect in the fluid that mixes the fluid to attain a substantially equal temperature in the channel sections of the passageway, which improves the thermal transfer of energy from the fins of the heat exchanger to the fluid.

27. A computer-readable medium comprising computer-executable instructions that, when executed on a processor, in a method of rapidly changing the temperature of a fluid between an inlet and an outlet in a system having a heat exchanger unit connected between the inlet and the outlet and thermoelectric means linked to the heat exchanger unit, the heat exchanger unit having a first member interleaved with a second member such that a passageway is defined between the first and second members for the fluid to flow through, directs a device to: calculate the difference between received temperature values of the fluid at the inlet and at the outlet and compare said difference to a predetermined temperature difference At or compare the outlet fluid temperature to a predetermined outlet temperature stored in a memory device; if a difference between the received values and the predetermined temperature difference Δΐ stored in said memory device is detected or a difference between the outlet fluid temperature and the predetermined outlet temperature is detected, calculate the amount of energy or power that is required to be delivered to the heat exchanger; and

Substitute Sheet

(Rule 26) RO/AU send a signal to a switch means connected to the thermoelectric means and activate an appropriate number of switches in said switch means so that respective thermoelectric devices said thermoelectric means can draw energy to then heat or cool the fluid to attain the predetermined temperature difference At or the predetermined fluid outlet temperature.

Substitute Sheet

(Rule 26) RO/AU

Description:
METHOD AND SYSTEM OF RAPID HEATING AND COOLING OF A FLUID

FIELD OF THE INVENTION

This invention relates to a method and system of providing rapid heating and/or cooling of a fluid and more particularly to a system and method of rapidly changing the temperature of a fluid between an inlet and an outlet.

BACKGROUND OF THE INVENTION

The heating and cooling of fluid systems, in particular water systems, are installed in the vast majority of residential and business premises in developed countries. In some countries the most common energy source for such heating and cooling is electricity. Electricity is now considered a practical necessity for residential and commercial premises. With electricity consumption growing annually, the projected increase in electricity consumption for residential and commercial use has become a central issue in the ongoing debate regarding carbon stabilisation and meeting the goals of the climate change discussions globally. The most common form of fluid heating or fluid cooling systems involves a storage tank in which fluids, such as water, are heated or cooled slowly over time to a pre-determined temperature. The fluid in the storage tank is maintained at a predetermined temperature as fluid is drawn from the storage tank and replenished with warmer or cooler inlet fluid.

A common form of cooling is vapour cycle refrigeration which includes the use of an evaporator, condenser and compressor. A suitable refrigerant travels through a long circuit of tubing and in the process changes from a vapour to a liquid and then back to a vapour and is connected to the mains electricity supply, which is controlled by a thermostat or temperature- monitoring device.

Electrically-cooled fluid storage systems that use vapour cycle refrigeration are generally considered to be energy inefficient as they operate on the principle of storing and cooling water to a predetermined temperature even though the consumer may not require cold fluid until some future time. As thermal energy is lost from the cold fluid in the storage tank, further

consumption of electrical energy is required to re-cool that fluid to the predetermined

temperature. Ultimately a consumer may not require cold fluid for some considerable period of time. The same can be said for electrically heated storage systems. During the time where the consumer does not require fluid, either hot or cold, electric hot/cold fluid storage systems

Substitute Sheet

(Rule 26) RO/AU continue to consume energy in order to heat or cool the fluid in preparation for a consumer that requires such hot or cold fluid at any particular time.

Vapour cycling refrigeration is incompatible with on-demand cooling of fluids due to the build-up of pressure in the system and therefore cannot be switched on and off effectively. On demand vending water systems store fluid and when the demand is great the system depletes its fluid volume and time and energy is thereafter needed to cool or heat the volume of water back to the predetermined temperature. In the case of vapour cycling refrigeration, continuous on- demand cooling is not possible.

The present invention seeks to provide a method and (off-grid) system which is energy efficient and substantially uses renewable energy resources to fuel its system electrical storage device. The present invention seeks to enable use of a system to avoid inefficiencies, that necessarily occur as the result of storing hot or cold fluid, by providing rapid heating and/or cooling of fluid so that the fluid temperature reaches a predetermined temperature level within a short period of time. The present invention also seeks to use the principles associated with thermo-electric heating and refrigeration where there are no moving parts and the refrigerant is replaced by two dissimilar conductors. Such a system provides continuous on-demand heating and cooling of fluid.

SUMMARY OF THE INVENTION According to a first aspect of the invention, there is provided a system for rapidly changing the temperature of a fluid between an inlet and an outlet, said system including: a heat exchanger unit connected between the inlet and the outlet and having a first member interleaved with a second member such that a passageway is defined between the first and second members for the fluid to flow through; thermoelectric means linked to one or both the first and second members for altering the temperature of the fluid; a source of electrical energy connected to the thermoelectric means ; control means linked to the thermoelectric means; a first temperature sensor for measuring the temperature of the fluid input to the heat exchanger unit at the inlet;

Substitute Sheet

(Rule 26) RO/AU a second temperature sensor for measuring the temperature of the fluid output from the heat exchanger unit at the outlet; wherein said control means controls the amount of energy drawn by the thermoelectric means to change the temperature of the fluid to match a predetermined temperature difference Δΐ of the fluid between the inlet and the outlet or the temperature of the fluid at the outlet based on signals received from each of the first and second temperature sensors.

The system may further include flow sensor means positioned at or near the outlet for measuring the flow of fluid leaving the outlet. The control means may receive signals from any one or more of the first temperature sensor, the second temperature sensor or the flow sensor means, said signals representative of temperature of the fluid or flow rate of the fluid. The control means preferably has a memory device and a processor device, said memory device storing values associated with said predetermined temperature difference At and t ou t where t ou t the is the set temperature at the outlet, said processor device receiving said signals representative of temperature of the fluid or flow rate of the fluid. Preferably the processor device compares the received signals to the predetermined At and t out stored in said memory device.

The control means preferably has switch means connected to said thermoelectric means and to said processor device, such that when the value or values of the measured At and t ou t from the received signals differ from the predetermined At and t out , the processor device controls the switch means to enable said thermoelectric means to receive energy from the electrical energy source.

In an embodiment the thermoelectric means includes one or more thermoelectric devices. The heat exchanger unit can include a frame for housing said first and second members and a pair of heat sinks mounted at respective sides of the heat exchanger unit. The first member and the second member preferably form part of a heat exchanger in the heat exchanger unit, said first member connected to said thermoelectric means by a first plate member and said second member connected to said thermoelectric means by a second plate member, each of said first and second plate members adapted to transfer energy from said thermoelectric means to said first and second members of the heat exchanger.

The first member preferably includes a first set of substantially parallel fins and said second member includes a second set of substantially parallel fins, said second set of

substantially parallel fins being interleaved with respective fins in said first set of fins so as to define said passageway for fluid to flow through, the passageway including multiple channel

Substitute Sheet

(Rule 26) RO/AU sections with each channel section defined between a fin of the first set of fins and a fin of the second set of fins.

The thermoelectric means may include one or more thermoelectric devices with each said one or more thermoelectric devices connected to said source of electrical energy. The arrangement of the first and second sets of fins in said frame may be such that a reservoir is formed at an end of each fin in either or both sets of fins for the fluid to temporarily reside in. In an embodiment, the flow of fluid through the heat exchanger is laminar, which together with the reservoir at the end of each fin creates a vortex effect in the fluid that mixes the fluid to attain a substantially equal temperature in the channel sections of the passageway, which improves the thermal transfer of energy from the fins of the heat exchanger to the fluid.

In one embodiment the fluid is heated through said thermoelectric means. In a further embodiment the fluid is cooled through said thermoelectric means by reversing the direction of current supplied from the electrical energy source through the thermoelectric means.

The heat exchanger unit preferably has a fan unit and a pair of side panels that attach to the fan unit, each side panel having an inwardly diverging channel such that a gap is formed between the channels through which air is blown under pressure from the fan unit to cool the heat sinks.

According to a second aspect of the invention, there is provided a method of rapidly changing the temperature of a fluid between an inlet and an outlet in a system having a heat exchanger unit connected between the inlet and the outlet and thermoelectric means linked to the heat exchanger unit, the heat exchanger unit having a first member interleaved with a second member such that a passageway is defined between the first and second members for the fluid to flow through, said method including: measuring the temperature of the fluid input to the heat exchanger unit at the inlet; measuring the temperature of the fluid output to the heat exchanger unit at the outlet; controlling the amount of energy drawn by said thermoelectric means to change the temperature of the fluid in response to the measured temperatures at the inlet and the outlet; stopping the provision of energy to said thermoelectric means when the difference in temperature of the fluid between the inlet and the outlet matches a predetermined fluid temperature difference Δΐ or a predetermined outlet fluid temperature has been reached.

Substitute Sheet

(Rule 26) RO/AU According to a third aspect of the invention, there is provided a heat exchanger for use in a system for rapidly changing the temperature of a fluid between an inlet and an outlet;

including: a first member and a second member interleaved between one another and defining a passageway for fluid to flow therethrough, said fluid flowing from the inlet to the outlet; means for heating or cooling either one or both the first and second members and connected to said first and second members; wherein the temperature of the fluid at the inlet and the outlet is measured and if the temperature difference between the fluid at the inlet and at the outlet is not equivalent to a predetermined temperature difference At or the outlet temperature is not equivalent to a predetermined outlet fluid temperature, then energy is provided to said means for heating or cooling to heat or cool the fluid until the temperature difference between the fluid at the inlet and at the outlet matches said predetermined temperature difference At or until the predetermined outlet fluid temperature has been reached.

According to a fourth aspect of the invention, there is provided a computer-readable medium comprising computer-executable instructions that, when executed on a processor, in a method of rapidly changing the temperature of a fluid between an inlet and an outlet in a system having a heat exchanger unit connected between the inlet and the outlet and thermoelectric means linked to the heat exchanger unit, the heat exchanger unit having a first member interleaved with a second member such that a passageway is defined between the first and second members for the fluid to flow through, directs a device to: calculate the difference between received temperature values of the fluid at the inlet and at the outlet and compare said difference to a predetermined temperature difference At or compare the outlet fluid temperature to a predetermined outlet temperature stored in a memory device; if a difference between the received values and the predetermined temperature difference At stored in said memory device is detected or a difference between the outlet fluid temperature and the predetermined outlet temperature is detected, calculate the amount of energy or power that is required to be delivered to the heat exchanger; and send a signal to a switch means connected to the thermoelectric means and activate an appropriate number of switches in said switch means so that respective thermoelectric devices in

Substitute Sheet

(Rule 26) RO/AU said thermoelectric means can draw energy to then heat or cool the fluid to attain the predetermined temperature difference At or the predetermined fluid outlet temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention will hereinafter be described, by way of example only, with reference to the Figures in which:

Figure 1 is a block diagram of a system that enables rapid heating and/or cooling of fluid;

Figure 1 A is a flow diagram showing processes that a control means undertakes to control heating or cooling of a fluid;

Figure IB is a block diagram showing the components of the control means; Figure 2 is a perspective view from above of apparatus for heating and/or cooling fluid, in a fully assembled state;

Figure 3 is an exploded perspective view of the apparatus of Figure 2;

Figure 4 is a further exploded perspective view of the apparatus of Figure 2 showing the inner core area of the apparatus; Figure 5 is a perspective view from above of a heat exchanger unit and its enclosures including a pair of heat sink units;

Figure 6 is a perspective exploded view from above of the heat exchanger unit from one side in Figure 5;

Figure 7 is an exploded view from above of the heat exchanger unit of Figure 6 showing further components, particularly the heat exchanger;

Figure 8 is a perspective exploded view from above of both sides of the heat exchanger unit of Figure 7;

Figure 9A is a perspective view of a frame in which a heat exchanger is housed;

Figure 9B is a front view of the heat exchanger fitted within the frame of Figure 9A and taken as a cross-section across line A-A in Figure 9C;

Figure 9C is a top view of the frame of Figure 9A;

Substitute Sheet

(Rule 26) RO/AU Figures 1 OA is a sectional view of the frame of Figure 9A with the heat exchanger contained therein taken on line B-B in Figure 10B and showing part of a fin assembly and corresponding reservoir;

Figure 1 OB is a front view of the heat exchanger showing an enlarged portion of parts of interleaving fin assemblies of the heat exchanger;

Figure IOC is a top view of the frame of the heat exchanger;

Figure 10D is a sectional view along line D-D in Figure 10B of the heat exchanger frame and showing part of a further fin assembly and corresponding reservoir;

Figures 1 1 A, 1 IB and 1 1C are similar views respectively to Figures 9 A, 9B and 9C but with Figure 1 IB showing the flow of fluid throughout the heat exchanger;

Figure 12A is a top view of a section taken along line B-B in Figure 12B and showing the fluid flow through the heat exchanger;

Figure 12B is a sectional view of fluid flowing through the heat exchanger; and

Figure 12C is a top view of the frame which houses the heat exchanger. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to Figure 1 there is shown a block diagram of a system 10 used to rapidly heat and/or cool a fluid, such as water. The system 10 has a heat exchanger apparatus 12 which has an inlet 14 and an outlet 16. Fluid, typically water, to be heated or cooled is passed through the inlet 14 and progresses on a path through the heat exchanger apparatus 12 to the outlet 16.

Thermoelectric devices 22 are in contact with the heat exchanger unit in apparatus 12 and are provided with power through DC electric power source 20 through link 71 and are also under the control of a control means 18 which includes a micro-processor 31. Electrical energy sensor 30 detects how much current or power is drawn by the thermoelectric devices 22 (or 68, 70 in Figure 8) in order to heat or cool the fluid flowing through the heat exchanger unit of apparatus 12. Input (or first) temperature sensor means 26 and output (or second) temperature sensor means 28 are directly linked respectively through links 11 and 13 to the control means 18 to respectively provide the temperature of the fluid flowing into and out of the heat exchanger apparatus 12 in order to calculate how much power is required to cool or heat the fluid in the heat exchanger to a predetermined temperature. A flow sensor device 24 connected in the downstream portion of the fluid flow is also connected to the control means or central unit 18

Substitute Sheet

(Rule 26) RO/AU through link 15 to provide an indication of the rate of flow of fluid out of the heat exchanger unit. The system enables heating or cooling of fluids that fall within a viscosity range of 1 Centipoises (cps), such as water, and 5000 cps, so that the system is not sensitive to fluids of varying turbidity or conductivity. Referring to Figures 1A and IB, there is shown a flow diagram 19 depicting the various steps taken by control means 18 in adjusting the amount of energy delivered to one or more thermoelectric devices 68, 70 (see Figure 8) to control the temperature of the fluid so that the temperature between the inlet 14 and the outlet 16 matches a preset (or set) temperature difference At or preset (or set) outlet temperature t ou t- At step 21 signals are received by the control unit 18 through links 39 from each of the various temperature sensors 26, 28 and any other sensors distributed throughout the heat exchange unit 36 (see Figure 4). Signals from flow sensor 24 are also received through link 39. The signals can be transmitted at preset intervals or continuously and contain information on temperature or flow rate of the fluid entering, within and exiting the apparatus 12. At step 23, the received signals, particularly those relating to temperature of the fluid, are compared to a preset or predetermined At (TDIFF) and/or outlet temperature t out which are stored in memory 33 of control unit 18. The preset values have been manually entered into memory 33 through control pad or keypad 35. A computer program stored in memory 33 instructs processor 31, such as a microprocessor, to compare the received temperature values to those stored in memory 33. At step 25, if a difference between the received values and those stored in memory 33 is detected, the computer program instructs the processor 31 to calculate the amount of energy or power that is required to be delivered to the heat exchanger unit 36 (and for how long the calculated energy is to be delivered) to rapidly achieve the preset At and preset outlet temperature at step 27. This will be based on the equations (1) and (2), described hereinafter, and values for specific heat/cooling capacity of the fluid, density of the fluid, volume of the fluid in the heat exchanger unit, applied voltage of the electrical source which are all input to, and stored in, the memory 33. When the processor 31 determines how much energy is required and for how long it is to be delivered to the

thermoelectric devices 68, 70 (or 22), then at step 29 the processor 31, under instruction from the computer program stored in memory 33, sends a signal to switch means 37 which connects to the thermoelectric devices 68, 70 (or 22) through links 17 (or links 72, 74 in Figure 8). The switches of switch means 37 can be co-located with respective thermoelectric devices 68, 70 rather than be located in the control unit 18. Each of the thermoelectric devices 68, 70 may be individual or grouped so that some thermoelectric devices heat or cool specific segments of the heat exchanger unit. The switch means 37 includes a series of switches, typically FET or Triac switches, that g

Substitute Sheet

(Rule 26) RO/AU are linked to the individual or grouped thermoelectric devices 68, 70. Depending on the required energy to be drawn from the electrical power source 20, the microprocessor 31 activates the correct number of switches in the group of switches 37 so that the respective thermoelectric devices 68, 70 can draw energy from the connected power source 20 to then heat or cool the fluid to the desired temperature. Once the preset At and/or outlet temperature t out have been attained the microprocessor 31 switches each of the relevant switches off. At step 25, if no change to the preset At and/or outlet temperature t out has been detected, the process returns to step 21.

Referring to Figures 2 and 3 there is shown a heat exchanger apparatus 12 in the form of a housing 47 which includes top panel 32, bottom panel 34 and side panels 38 and 40. A fan unit 42 is adapted to connect to various flanges 44 on each of the side panels 38 and 40. The fan unit 42 houses three separate fans 46 and is enclosed at an outer end by respective fan grilles 48. The side panels 38 and 40 diverge inwardly to form channels 41 and 43 which results in a narrow gap or opening 45 extending along the full height of the panels 38, 40 at the apices of each of the channels 41, 43. This arrangement forces air blown by the fans 46 to gather and move quickly through the opening 45 under pressure to provide rapid flow of air to the heat sinks 58 and 66 (Figure 5) to provide adequate cooling to the heat sinks 58, 66.

Referring to Figures 4 to 8, these Figures progressively show exploded views of all of the components of the heat exchanger unit 36 of apparatus 12. The apparatus 12 consists of a heat exchanger unit 36 covered by various panels 32, 34, 38 and 40 making up housing 47. The heat exchanger unit 36, as more clearly seen in Figure 8, includes housing or frame 50 which houses a first member (or portion) 52 and second member (or portion) 60 of the heat exchanger unit that interleave with each other to provide a passageway for fluid to flow while at the same time being heated or cooled. Each of the first member 52 and second member 60 are shaped in a comb-like structure and have a plurality of fins which interleave with each other when they are both fitted and secured in housing 50. Each of the fins 55 of the first member 52 are integrally formed with a first plate member 54 which is termed a first hot-cold plate. Thus the first member 52 may include integrally the fins 55 and the first plate member 54. Attached to the side of plate member 54, on the opposite side of the fins 55 of the first member 52, are a series of heating or cooling devices 68, referred to as thermoelectric devices, which each have a pair of leads 72 that are connected to electrical source 20 for providing current to one or more of the units 68 in a first direction to heat plate member 54 or in a reverse second direction to cool plate member 54. Each of the devices 68, 70 use the well-known Peltier effect. The plate member 54 fits into the housing 50 and is more clearly shown in Figure 6 with the leads 72 fitting into apertures or

r

Substitute Sheet

(Rule 26) RO/AU recesses 69 of insulating plate 56. The insulating plate 56 has apertures 57 which fit around respective thermoelectric devices 68 as well as recesses 59 for mounting flanges 61 located on an outside face 49 of frame 50. These are so designed so that the insulating plate 56 sits flush against the outside face 49 of frame 50. A first heat sink structure 58 is then fitted against the outer surface 51 of the insulating plate 56 and is secured to the frame 50 through suitable securing means through respective screw apertures 63 which are aligned with respective mounting flanges 61 of the frame 50.

Referring to Figure 8 again, the second member 60 of the heat exchanger unit 36 also has a series of fins 63 that extend in a comb-like structure and are integrally affixed to second plate member 62, which is also a hot-cold plate, for heating or cooling the respective fins 63. The second member 60 may include integrally the series of fins 63 and the second plate member 62. Both the second member 60 and plate member 62 fit within the other side of housing 50 such that the fins 63 of second member 60 mesh with the fins 55 of the first member 52. Attached to the outer side of plate member 62 are a series of heating/cooling devices 70 in the form of thermoelectric devices. Each of the thermoelectric devices 70 have leads 74, that fit into apertures or recesses 73 of insulating plate 64, which are connected to the electrical energy source 20 for supplying current in one of two directions to effect the heating or cooling of plate member 62 which in turn heats or cools the fins 63 of the first member 60 and therefore heats or cools the fluid flowing through the heat exchanger. A second insulating plate 64 abuts against the plate member 62 and has apertures 65 that fit around respective thermoelectric devices 70, recesses 67 that fit around respective mounting flanges 53 of frame 50. The insulating plate 64 is sandwiched between plate member 62 and a second heat sink member 66. The overall configuration of the heat exchange unit 36 is shown in Figure 5. The heat sink members 58 and 66 are preferably made from aluminium. The effect of the fins 55 and 63 create the passageway 84 like a flat ribbon which provides efficient transfer of heat or coldness to the fluid.

Referring to Figure 9A there is shown a perspective view of frame 50 which houses the two member 52 and 60 of the heat exchanger unit. It shows an aperture 80 that provides access to fluid flowing through inlet 14. Similarly there is an aperture 82 at the bottom of the frame 50 that allows fluid to flow out of the outlet 16 shown in Figure 9B.

Referring to Figure 9B, fluid flows from a fluid source into inlet 14 and through the passageway 84 formed by the interleaving comb structures of each of the members 52 and 60 of the heat exchanger unit. During this time the fluid is either heated or cooled to a predetermined temperature and exits the outlet 16 at the bottom of the heat exchange unit 36 to be dispensed. A

Substitute Sheet

(Rule 26) RO/AU first temperature sensing means 26 is located in the path of the fluid flowing through the inlet 14 to measure the temperature of the fluid. There is a second temperature measuring means 28 positioned in the stream of fluid flow through the outlet 16 to measure the temperature at the outlet. Referring to the series of Figures 10A to 10D, Figure 10A shows a sectional view from below of the frame 50 in Figure 10B along the line B-B, while Figure 10B shows an enlarged portion of the interleaving fins 55 and 63 of the first and second members 52, 60 of the heat exchanger unit. Water flows from top to bottom as indicated by the arrows. The fins 55 are shaped as in Figure 10A with an angled side 59 so that reservoir 57 exists for water to temporarily collect as it moves through the heat exchanger unit. Similarly referring to Figure 10D, each of the fins 63 of the member 60 are angled so that the angled side 67 provides a further reservoir 65 for the fluid to gather. Therefore at the end of each fin, fluid is able to pool alternately in the respective reservoirs 57 and 65. This provides a facility for better mixing of the fluid as it progresses through each of the individual fins and provides better heat or energy transfer from each of the fins 55 and 63 to the fluid. Similarly it provides better transfer of coldness if the heat exchanger is being used to cool the fluid.

Figures 12B and 1 IB show sectional views of the heat exchanger with fluid filling the heat exchanger unit between the two members 52 and 60 of the heat exchange apparatus.

Referring back to Figure 1 , the operation of the system will now be described. Fluid that is to be heated enters the heat exchanger apparatus 12 through inlet 14. The fluid, typically water, enters the inlet 14 so that it travels through the passageway 84 formed by the fins 55, 60 of members 52 and 60 of the heat exchanger unit 36. Heat that is required to be supplied to the system in order to heat the fluid is controlled by control means 18 based on inputs from a flow sensor device 24, which measures the flow rate of the downstream fluid upon exit from the outlet 16, measurement of the temperature of the fluid input to the apparatus 12 via a temperature sensor 26 and also fluid temperature that is output from the apparatus 12 via temperature sensor 28 which measures the output fluid temperature at outlet 16. A predetermined At, which is a difference in temperature between the outlet 16 and inlet 14 is set within the control means 18. In order to maintain the At temperature difference, energy may need to be supplied in the form of heat to a thermoelectric device or devices 22, typically in the form of the thermoelectric units 68 and 70, so that heat can be supplied to the plate members 54 and 62 which directly contact the fins 55, 63 of the members 52 and 60 of the heat exchanger unit. Both plates 54 and 62 are preferably made from a high conductor of heat/coldness such as aluminium or copper and kept as

Substitute Sheet

(Rule 26) RO/AU thin as possible to efficiently transfer heat or coldness to the respective fins 55, 63. Current is delivered to the thermoelectric devices 68 and 70 through an electrical power source 20, which is typically a direct current electrical energy source. The DC storage device 20 can be rechargeable via renewable solar energy or wind generated electrical energy or any other electrical energy source that is available in the public domain. Thus the input temperature and the output temperature are constantly monitored, as well as the flow sensor 24, by the control unit or control means 18 to provide optimum heating or cooling by maintaining the At temperature range. The flow rate, for example when a user activates a valve to release fluid out of outlet 16, will provide an indication as to how much the heat exchanger unit 36 will need to be heated or cooled. If the flow rate is fast, then the fluid will need to be heated to a higher temperature or cooled to a lower temperature (depending on the application) more quickly. Therefore control means 18 activates as many thermoelectric modules 68, 70 as needed to rapidly heat or cool the fluid. The delivery of heated or cooled fluid to the end user is instantaneous for a given flow rate. It is to be noted that the desired temperature of the output fluid may be adjusted manually by the user through an adjustable control means. An electrical energy sensor system 30 may also be connected to the electrical power source 20 for monitoring the amount of current drawn by each of the one or more thermoelectric devices. The thermoelectric devices 68, 70 are preferably made from ceramic material that can withstand temperatures up to 300 degrees Celsius. They can be made any suitable size and shape. The thermoelectric devices 68, 70 may be switched on and off as required and as many temperature sensor units can be used to measure the temperature of the fluid in the heat exchange unit. For example, a temperature sensor can be placed in the flow of the fluid in any number of positions in the passageway 84 at regular intervals. Depending on the resultant measurements, if heat/coldness needs to be applied to a certain segment of the heat exchange unit, such as in passageway 84, then an appropriately positioned thermoelectric device can be switched on until the overall preset temperature difference At is reached. Each segment of the heat exchange unit 36 can be linked to one or more grouped thermoelectric devices 68, 70.

As mentioned previously, a temperature difference may be determined between the inlet fluid at inlet 14 and a desired temperature of the fluid exiting outlet 16. The volume of the fluid passing through the heat exchange unit 36 can be determined by the dimensions of the pathway through which the fluid flows. There is approximately a 2mm gap between the respective fins 55, 63 of the members 52 and 60 and a height of about 30mm that defines the passageway. The volume of each of the reservoirs 57 and 65 will also need to be taken into account to arrive at a final volume for fluid. The amount of time for which the fluid is heated or cooled to the preset

Substitute Sheet

(Rule 26) RO/AU temperature can be determined by measuring the flow rate of the fluid through the passageway, which is done through the flow measuring device 24. The temperate increase or decrease of the fluid is proportional to the amount of electrical power applied to the fluid. The amount of power required to raise the temperature of the fluid or decrease the temperature of the fluid by a predetermined amount is proportional to the mass or volume of the fluid being heated or cooled and to the fluid flow rate through the passageway. In order to cool the fluid, the current directed to each of the thermoelectric devices 68, 70 is simply reversed at the terminals of the electrical power source 20 initiating the Peltier Effect in the devices 68, 70.

The flow of fluid through passageway 84 is laminar in the sense that "layers" of fluid are created which travel at different speeds through the passageway 84. The passageway 84 between respective fins 55, 63 of the members 52, 60 has an inlet portion that leads from an outlet of the previous passageway (upstream) and an outlet that leads into the inlet of the succeeding passageway in the heat exchanger unit (downstream). At each end, between the outlet portion of one passageway portion and the inlet of the succeeding passageway portion, there is reservoir 57 or 65. Fluid nearest the end of a respective fin, such as near angled sides 59, 67, will travel more quickly than fluid further away from the fin end, in the reservoir. Together with the existence of the reservoir (57 or 65) and the speed differential of fluid flow around the end of the fin creates a low and high pressure difference at each exit and entry of consecutive passageways. This creates a vortex effect in the fluid that mixes the fluid to attain a substantially equal temperature in the passageway 84, which improves the thermal transfer of energy (heat or cooling) from the fins 55, 63 of the heat exchanger unit 36 to the fluid.

The energy required to increase or decrease the temperature of the fluid flowing through the heat exchange unit 36 can be determined by the following equations:

Energy = Specific Heat/Cooling Capacity x Density x Temp-Change (1) The DC energy per unit of time required to increase or decrease the temperature of the fluid can be determined by:

Power (P)kWh = Specific Heat/Cooling Capacity(SHC) x Mass/Vol TV) x Temp-Change (At)

Time (T) (2)

When a user requires the fluid to be heated or cooled, the user commences activation of the system by opening a control valve. For example, the person may wish to dispense cold water or hot water into a cup. The system sensors 24, 26 and 28 are connected to the control means 18,

Substitute Sheet

(Rule 26) RO/AU which is micro-processor controlled, and provide signals indicating temperature or flowrate to the control unit 18, which thereafter controls the applied heating or cooling sequence to the fluid flow. The flow of fluid is detected by the flow/pressure sensor 24 and provides a signal to the control unit 18 which causes the initiation of the heating or cooling cycle. The temperature of the incoming fluid is measured at the inlet 14 by the first temperature sensor 26 and compared with a pre-set desired temperature difference or At for the fluid to be emitted at outlet 14 from the system. From these two values the required change in fluid temperature from inlet to outlet can be determined and the amount of DC electrical heating or cooling energy that is required to be provided to one or more sets of thermoelectric devices 68, 70 embedded in the heat exchanger apparatus 12. Once the outlet temperature is reached and sensed by the output temperature sensor 28, then power is switched off or cut to the thermoelectric devices or modules 68, 70.

The temperature of the inlet fluid may be repeatedly measured over time and as the value of the measured inlet water temperature changes, the calculated value, as calculated by the control means 18, for the required temperature change from the inlet 14 to the outlet 16 can be adjusted accordingly. The control unit 18 then calculates or selects the required number of thermoelectric devices 68, 70 to be switched on to provide a correct or predetermined outlet temperature.

Computing means, in the form of microprocessor 31 in the control unit 18, is used to determine the DC electrical power that should be delivered to one or more of the thermoelectric modules 68, 70 (Thermoelectric Couple Segments TSn) in the heat exchanger unit 36 in order to heat or cool the fluid passing through the heat exchanger unit 36. Once the optimised DC electrical power that should be delivered to some or all of the thermoelectric modules 68, 70 has been determined, the processor or CPU 31 in the control unit 18 calculates the DC electrical energy that should be applied to each of the thermoelectric modules or segments 68, 70 using the following equations. If the power required (Preq/t) for the thermoelectric modules is known, then the DC power that is drawn by the thermoelectric modules (segments) 68, 70 can be measured through the measuring unit 30.

Voltage TSn (Vapp«)=Power TS« (Preq«)/Current TS«(IS«) (3)

Vappw = Preqw / ISn (4)

where Voltage TSn, Vappn is the voltage that should be applied to the particular Thermoelectric Couple Segments (any of 68, 70) determined by the temperature difference t=Tset - Tin; Power

Substitute Sheet

(Rule 26) RO/AU TSn (Preqfl) is the power required to be delivered to the Thermoelectric Couple Segments; and \Sn is the current drawn by the respective Thermoelectric Couple Segments to deliver the power to achieve the correct fluid temperature output at the outlet 16.

As part of the initial heating or cooling sequence, the applied DC electrical energy can be set 5 to a relatively low value in order to determine the initial specific thermoelectric devices that need to be switched on to effect the temperature change.

Substitute Sheet

(Rule 26) RO/AU




 
Previous Patent: CANTILEVER BRACKET

Next Patent: ROSTER DESIGN METHODS AND SYSTEMS