AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT (ORIGINAL) Name of Applicant: Inform Energy Pty Ltd Actual Inventors: John David AITKEN Address for Service: DAVIES COLLISON CAVE, Patent Attorneys, Level 3, 303 Coronation Drive, Milton 4064, Queensland. Invention Title: "Temperature control apparatus" Details of Associated Provisional Application No: Australian Provisional Patent Application No. 2008904023, filed 6 August 2008 The following statement is a full description of this invention, including the best method of performing it known to us: Q:\oper\ajs\2009\juIy 2009\40134296 inform AU It PO filing complete 208.doc - 27/7/09 P perbjsispecA41342%_AU completedoc-27Af/279 TEMPERATURE CONTROL APPARATUS Background of the Invention The present invention relates to a method and apparatus for controlling the temperature of a building, and in particular for controlling the temperature using a thermal transfer system. 5 Description of the Prior Art The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to [0 which this specification relates. Temperature control within buildings is typically achieved through a combination of heating and air conditioning systems. In one example, this may be achieved through the use of separate systems, such as central heating and separate air conditioning, or combined apparatus such as reverse cycle air conditioning. However, such systems typically utilise a 5 significant amount of energy to operate, making them expensive to operate and environmentally unfriendly. Summary of the Present Invention The present invention seeks to substantially overcome, or at least ameliorate, one or more disadvantages of existing arrangements. 20 In a first broad form the present invention seeks to provide apparatus for controlling the temperature of a building, the apparatus including: a) a heat storage vessel for storing heat transfer medium, the heat storage vessel including a number of heat storage elements; b) a pump for pumping heat transfer medium through a heat transfer pipe extending 25 through a part of the building; c) a building temperature sensor for sensing a building temperature; P:operjs\spci1Aul3129 AU compicie doc-27A07/2009 -2 d) a controller coupled to the temperature sensors, the controller being for controlling the pump in accordance with the sensed building temperature to thereby selectively transfer heat transfer medium through the heat storage vessel and the heat transfer pipe. 5 Typically the controller is for: a) comparing the building temperature to the building temperature range; b) if the building temperature is greater than the building temperature range, causing the pump to pump thermal transfer medium from a first port of the heat storage vessel, the first port being positioned below a second port. 10 c) if the building temperature is lower than the building temperature range, causing the pump to pump thermal transfer medium from the second port. Typically the apparatus includes a vessel temperature sensor, coupled to the controller, for sensing a vessel temperature. Typically the controller is for controlling the pump in accordance with the sensed vessel 15 temperature. Typically the controller is for: a) comparing the vessel temperature to a vessel temperature range; b) depending on the results of the comparison, selectively causing at least one of: i) heating of the heat transfer medium; and, 20 ii) cooling of the heat transfer medium. Typically the heat storage elements include a phase change material. Typically the phase change material is a hydrated calcium or magnesium chloride. Typically the heat storage elements have a planar shape. Typically the controller is a processing system. 25 In a second broad form the present invention seeks to provide a method of controlling the temperature of a building, the method including, in a controller: P:\oprajs\speciW)11426_AU completedoc.-27/0712009 -3 a) determining a building temperature; and, b) controlling a pump in accordance with the sensed building temperature to thereby selectively transfer heat transfer medium through the heat storage vessel and the heat transfer pipe, the heat storage vessel including a number of heat storage elements; 5 Brief Description of the Drawings An example of the present invention will now be described with reference to the accompanying drawings, in which: Figure IA is a schematic diagram of an example of temperature control apparatus; Figure lB is a flow chart of an example of a process performed by the apparatus of Figure 0 1A; Figures 2A and 2B are schematic side and plan views of an example of a heat storage vessel; Figures 3A and 3B are schematic side and plan views of an example of a building; Figure 4 is a schematic diagram of a second example of temperature control apparatus; Figure 5 is a schematic diagram of an example of a controller; and, 5 Figure 6 is a flow chart of an example process for controlling the apparatus of Figure 4. Detailed Description of the Preferred Embodiments An example of a temperature control apparatus will now be described with reference to Figure lA. In this example, the temperature control apparatus includes at least one heat storage vessel 20 100 for storing a heat transfer medium, which may be any fluid capable of storing heat, such as water, thermal oil, or the like. The heat storage vessel 100 is coupled to a heat transfer pipe provided in a building 110 via connecting pipes 120, 122. A pump 121 is provided to allow the heat transfer medium to be pumped through the heat transfer pipe, as will be described in more detail below. In one example, the pump can be adapted to allow the heat 25 transfer medium to be pumped in the direction of arrow 123 or the direction of arrow 124. The apparatus typically includes a controller 130 for controlling the operation of the pump 121. The controller 130 may be coupled to a building temperature sensor 131, which senses P iopcejs4pec\401342)6_AU complete doc-27l7/2009 -4 a temperature of the building 110, allowing the pump 121 to be operated in accordance with a building temperature. The apparatus may also include a vessel temperature sensor 132, for sensing the temperature of the heat storage vessel 100, which can optionally also be used in controlling operation of 5 the pump 121. An example of operation of the temperature control apparatus will now be described with reference to Figure IB. In this example, at step 150, the controller 130 operates to determine the building temperature. At step 160, the controller 130 determines if the building temperature is o acceptable. This is typically achieved by comparing the building temperature to an indicated acceptable building temperature range, which may be previously stored and/or set in accordance with user preferences. If the building temperature is acceptable, the process returns to step 150. Otherwise, the controller 130 activates the pump at step 170, causing heat transfer medium to be transferred 5 through the heat transfer pipe, thereby causing the heat transfer medium to heat or cool the building 110. This process continues until the building temperature is again within acceptable limits, at which point the pump can be stopped, with the process returning to step 150, to continue monitoring the building temperature. Thus, as the building heats up during the day, heat transfer medium at a lower temperature is 20 pumped from the heat storage vessel 100, through the heat transfer pipe, thereby removing heat from the building 110. The heated heat transfer medium is returned to the heat storage vessel 100, so that the temperature of heat transfer medium in the heat storage vessel 100 increases, thereby allowing the heat storage vessel 100 to act as a heat sink. In the evening, when the building cools, the building temperature falls below that of the heat transfer 25 medium in the heat storage vessel 100, so that pumping the heat transfer medium through the heat transfer pipe returns heat to the building 1 10. The effective thermal mass of the heat transfer medium stored in the heat storage vessel 100 therefore acts as a heat sink or source for the building 110. In one example, to increase the P0 pa fjs\s 40134296_AU cmplet doc.27/7f/2(X)9 -5 effective thermal mass, the heat storage vessel 100 can contains a phase change material, such as a hydrated calcium or magnesium chloride, which undergoes a phase change at temperatures in the region of 17*C to 24'C. Thus, when the building 110 is being cooled, heat transfer medium heated by the building 5 110 is supplied to the heat storage vessel 100. Heat is absorbed by the phase change material, causing the material to undergo a phase change, such as melting, thereby absorbing the heat as latent heat. This regulates the temperature of the heat transfer medium, so that it stays within the range 17*C to 24'C, thereby allowing it to provide cooling when the building temperature is elevated. 0 When the building subsequently cools, the heat transfer medium returning from the building I10 is cooler than the phase change material, causing the heat transfer medium to absorb heat from the phase change material, which in turn freezes. This process releases the stored latent heat, again maintaining the temperature of heat transfer medium within the 17*C to 24'C range, allowing heating to be provided to the cooler building 110. 5 The above described apparatus therefore allows heating and/or cooling to be provided by using a thermal transfer medium to extract heat from the building 110 during daytime, allowing the heat to be subsequently released at night when the building 110 is cooler. This process therefore allows the temperature control apparatus to substantially maintain a building temperature within an acceptable temperature range by selectively pumping heat 20 transfer medium from a heat storage vessel, through a heat transfer pipe. This can avoid the need to operate alternative heating/cooling systems, such as a boiler or air conditioning system, thereby reducing energy requirements, which in turn makes the temperature control system significantly cheaper and more environmentally friendly to operate than convention systems. 25 In the event that the temperature control apparatus is unable to provide sufficient heating or cooling, for example if the effective thermal mass provided by the heat storage vessel is insufficient for the prevailing conditions, additional heating or cooling may be provided using other means. This can be achieved, for example, using existing heating or cooling systems. Even in this situation, the amount of heating or cooling that will be required is P.operajs~spei41342%6_AU complete doc.27/07/2009 -6 minimised, and is substantially less than if the temperature control system is not used. Accordingly, even in this situation, this vastly reduces the need to use the existing heating or cooling systems, in turn leading to significant energy savings. It will also be appreciated that in circumstances where additional effective thermal mass is 5 required, a number of heat storage vessels may be connected together. In this situations, these could be connected either in series, or in parallel, allowing additional heat to be removed from the building, and then subsequently stored for later use. An example of a heat storage vessel including a phase change material is shown in more detail in Figures 2A and 2B. 0 In this example, the heat storage vessel 100 includes a housing 210, having a lid 211. The housing 210 defines a cavity 212, which in use can store the heat transfer medium. The housing may be made of any suitable material, such as a polycarbonate encapsulated insulating foam, although any suitable material that provides thermal insulating properties may be used. 5 In this example, the cavity 212 also contains a number of phase change elements 220, which are formed from an encapsulated phase change material, such as hydrated calcium and/or magnesium chlorides. Specific example materials include PC17 and PC25, supplied by Phase Change Products Pty Ltd, which have phase change temperatures of 17*C and 25*C respectively. 20 It will be appreciated the inclusion of either of these materials will increase the effective thermal mass of the heat storage vessel. In one example multiple different phase change materials could be used to maximise the energy storage provided over a wide operating temperature range. In this example, the phase change material can be provided in planar slabs that supported in a 25 spaced configuration, allowing flow of the heat transfer medium therebetween. In one example, the slabs have dimensions of 860 mm by 200 mm by 20 mm. This maximises the surface area of the heat transfer elements, whilst minimising the thickness of the phase change material. This ensures that heat supplied to the phase change material can rapidly P,\opcajs\spcaOl34296_AU complete doc-21A177209 -7 penetrate the entire slab, thereby heating all of the phase change material in the slab. This allows for the heat storage element 220 to heat up or cool rapidly, such as over a one hour period, thereby maximising the ability of the heat storage vessel 100 to provide rapid heating or cooling. 5 The heat storage vessel also typically includes first and second ports 230, 231 in the housing 210, allowing the heat transfer medium to be removed from and returned to the cavity 212. In one example, the first port 230 is positioned below the second port 231. In use, this allows heat transfer medium to be removed from either the top of bottom of the cavity 212. As there will typically be a temperature gradient along the length of the cavity 212 caused by 0 convention within the heat transfer medium, this will result in the heat transfer medium being hotter near the top of the cavity 212. Accordingly, heat transfer medium may be removed from the first port 230 when the building 110 is to be cooled, and from the second port 231, when the building is to be heated. As a result, in one example, the controller 130 can control the direction of flow of the heat transfer medium 123, 124, in accordance with the building 5 temperature. It will be appreciated that different sizes of heat storage vessel 100 and corresponding number and size of phase change elements 220 can be used to allow the effective thermal mass of the heat storage vessel to 100 be varied depending on the intended usage. Additionally, multiple heat storage vessels 100 can be connected together to provide 20 additional effective heat storage. This can be used in applications where additional heat storage capacity is required, such as in commercial buildings, or the like. An example of a building including a heat transfer pipe will now be described with reference to Figures 3A and 3B. In this example, the building 300 includes a floor 301 having a heat transfer pipe 310 25 extending therethrough. The heat transfer pipe 310 may be embedded in a floor material, such as concrete, or alternatively provided under floorboards, or the like. Any suitable arrangement may be used as long as this provides sufficient thermal conductivity between the thermal transfer medium and the building, thereby allowing for sufficient heat transfer between the building interior and the heat transfer medium.
P.1peajsspecMW(O34296_AU complIt doc-27/)7/209 -8 Whilst the heat transfer pipe 310 is embedded in the floor in this example, this is not essential, and alternatively, the heat transfer pipe may 3 10 be provided in a buildings walls and/or roof cavity. A second example of temperature control apparatus will now be described with reference to 5 Figure 4. In this example, similar reference numerals are used to denote similar components to those described above with respect to Figure IA. In this example, the apparatus also includes a chiller 410 and a heater 420, provided in the connecting pipes 120, 122, which are in turn connected to the first and second ports 230, 231 of the heat storage vessel 100. The chiller 410 and the heater 420 can be used to cool or heat o the heat transfer medium in the respective connecting pipe 120, 122, thereby allowing additional heating or cooling to be provided. Any form of heater and chiller may be used, and these can include, for example, gas or electric heaters, compression based chillers, or the like. Such additional heating or cooling can be used for example if there is insufficient temperature difference between the temperature of the heat transfer medium stored in the 5 heat storage vessel 100 and the building temperature to provide the required heating or cooling. Accordingly, in one example, the controller 130 is coupled to a vessel temperature sensor 430, allowing the temperature of the heat storage vessel 100 to be determined. Additionally, the controller 130 may be coupled to the chiller and heater 410, 420, allowing their operation 20 to be controlled. In such an example, the controller 130 is therefore adapted to determine the temperature of the building 110 and the heat storage vessel 100, and then use this information to control the pump 121, and optionally the chiller 410 and the heater 420. It will be appreciated from this example, and the example of Figure 1 above, that the controller 130 may be any form of 25 suitable controller. An example of a controller in the form of a processing system is shown for example in Figure 5.
P iepeCajs\cM)134296AU comptc doc-27AU7/2mXJ9 -9 In this example the controller 130 includes a processor 500, a memory 501, and input/output device (1/0 device) 502, such as input buttons, a key pad, display or the like, or an optional external interface 503. It will therefore be appreciated that the controller 130 may be in the form of a suitably programmed processing system, such as a computer, laptop, palm top, 5 PDA, or alternatively may be specialised hardware, a programmable logic controller, field programmable gate array (FPGA) or the like. In use, the controller 130 will execute a control protocol to allow control of the heat transfer apparatus as will now be described with reference to Figure 6. In this example, at steps 600 and 610 the controller 130 determines building and vessel o temperatures utilising the building temperature sensor 131 and the vessel temperature sensor 132, respectively. At step 620 the controller 130 determines if the building temperature is above an acceptable building temperature range. It will be appreciated that this may be achieved in any one of a number of ways. For example, this may involve comparing the current building temperature 5 to a threshold representing the maximum preferred building temperature, or the like. In one example, the threshold value could be stored in the memory 501, for example, in the form of an LUT (Look Up Table), or the like, allowing the processor 500 to perform the comparison. Alternatively, this could be based on user input commands, provided for example via the I/O device 502. 20 If it is determined that the building is too warm and cooling is required, then at step 630 it is determined if the vessel temperature is below a first threshold value, indicating that it is sufficiently cool to provide cooling. This first threshold value can be previously determined, or could alternatively be based either on the current building temperature. Thus, for example, if the heat transfer medium is more than a predetermined amount cooler that the current 25 building temperature, then this may be sufficient to allow cooling to be performed. If it is determined that the vessel temperature is suitable to perform cooling, then the pump is 121 activated at step 640, so that the coolest heat transfer medium is extracted via the port 230 from the lower region of the cavity 212, thereby providing cooling. In addition to this, Plopetjsspcci40134296_ AU cmpletedo-27A)2)9 -10 the pump flow rate may be controlled to adjust the flow rate of the heat transfer medium, which will in turn control the amount of cooling provided. In the event that additional cooling is required, then alternatively at step 650, the chiller 410 is activated in addition to the pump 121, thereby causing the heat transfer medium extracted 5 from the port 230 to be further cooled before it enters the heat transfer pipe 3 10. The degree of cooling provided by the chiller 410 may be controlled by the controller 130 based, for example, on the building and/or vessel temperatures. If cooling is not required, then at step 660, the controller 130 determines if the building temperature is below the acceptable building temperature range, in which case heating is 0 required. This is typically performed in a manner similar to that described above with respect to step 620. If it is determined that heating is required, then at step 670 the controller 130 determines if the vessel temperature is above a second threshold value, indicating that it is sufficiently warm to provide heating. If it is determined that the vessel temperature is suitable to perform 5 heating, then the pump is 121 activated at step 680, causing heat transfer medium to be extracted from the port 231 and transferred to the heat transfer pipe 310. Otherwise, the pump 121 and heater 420 are activated at step 690, thereby causing additional heating of the heat transfer medium extracted from the port 231, prior to it being supplied to the heat transfer pipe 310. 20 It will be appreciated that throughout the above example, the pump 121 and the chiller 410 or heater 420 if required, can be operated until the building temperature is within the acceptable building temperature range, in which case operation of the building temperature apparatus can be halted. Accordingly, the above described temperature control apparatus provides temperature control 25 by removing excess heat from within a building, to thereby provide cooling. The excess heat can be stored within a heat storage vessel 100, so that the heat may be subsequently returned to the building when heating is required. This vastly reduces reliance on traditional heating and or cooling systems, which are typically energy inefficient and expensive to operate. This P0perjsspeciWi342_96AU complete dc-27A)7/2K?)9 therefore results in reduced operating costs and energy usage, when compared to systems that utilise such traditional heating and/or cooling. Additionally the temperature control apparatus can include additional heating and/or cooling mechanisms, allowing these to be integrated into the temperature control apparatus. This 5 removes the need for separate additional heating/cooling systems, and maximises the efficiency of any heating or cooling that is required. Persons skilled in the art will appreciate that numerous variations and modifications will become apparent. All such variations and modifications which become apparent to persons skilled in the art should be considered to fall within the spirit and scope that the invention 0 broadly appearing before described.