WO2011047444A1

WO2011047444A1 - Thermal regulation system

Info

Publication number: WO2011047444A1
Application number: PCT/AU2010/001420
Authority: WO
Inventors: Shane West
Original assignee: Shane West
Priority date: 2009-10-23
Filing date: 2010-10-25
Publication date: 2011-04-28
Also published as: AU2010310897A1; CN102667349A

Abstract

A thermal regulating system (1, 101) for supplying hot water Io a building including a sub-floor water lank (50, 150) located under an in-slab floor (56) of the building; a solar water heater (10, 101) typically mounted on the roof of the building structure; a temperature sensor (30, 30) to measure the temperature in the range of 0 to 100 °C of the water in the tank (50, 150); al least one valve (40, 140) to control the flow of water along a water line (20, 22, 120, 122) in communication with the reservoir (50, 150) and the heater (10, 110); and a computer processor (170) to govern the operation of the valve (40, 140) according to the reservoir water temperature (175) measured by the sensor (30, 130).

Description

THERMAL REG ULATION SYSTEM

FIELD OF INVENTION

This invention relates to a temperature or thermal regulation system for a building. More particularly, this invention relates to a solar heating and radiant cooling system. Still more particularly, this invention relates to solar water heating and radiant cooling systems. Yet more particularly, this invention relates to a solar water heating system including sub-floor water storage, and external radiant cooling tanks to feed cooling water to the sub-n<x>r storage as a cooling system

BACKGROUND ART

The following references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the following prior art discussion does nol relate to what is commonly or well known by the person skilled in the art, but assists in tile understanding of the inventive step of the present invention of which • the identification of pertinent prior art proposals is but one part.

Economically and environmentally it is desirable to reduce fuel consumption required to heat buildings to a comfortable temperature. Governments and local authorities have responsibility for implementing strategies calculated to reduce fuel consumption, particularly carbon-based fuel consumption, according to good public policy and international obligations. Accordingly, there is a need for building heating systems that at least partial ly draw on renewable energy sources.

Buildings, including domestic and commercial structures, are typically connected to mains water for their clean water needs. However, there is an increasing recognition of the desirability ol^'localiscd water storage facilities to reduce reliance on mains water supplies, particularly in arid regions such as Australia. Such independent water storage typically takes the form of external or stand alone water tanks located near or adjacent building structures.

An object of the present invention is to ameliorate the aforementioned

disadvantages of the prior art or to at least provide a useful, alternative thereto.

STATEMENT OF INVENTION

Accordingly, in one aspect of the invention there is provided: of a building including:

a sub-floor fluid reservoir located in, under or on a cast and set material forming part of the floor of said building: utilised for varying the ambient temperature of said building;

a solar heater mounted on or in association with said system ;

a temperature sensor to measure the temperature in said reservoir, and at least one valve to control lluid flow along a line in communication with said reservoir and said healer to regulate the temperature of the fluid within the reservoir.

The system may be augmented with a radiant cooling system comprising external radiant cooling tanks to feed cooling water to the sub-floor storage as a cooling system.

The temperature sensor may include any such device suitable for measuring the water temperature in or about the reservoir. For example, suitable temperature sensors would include a digital device adapted to communicate with a central processing unit (CPU) and there are many off the shelf units suitable lor use in pools or spas that.would be suitable for the present purpose. Preferably, the temperature sensor includes one or more sensors located in, for example, a solar return pipe to the reservoir or optionally a solar pump suction pipe from the reservoir to the solar healer. The sensors may be in direct electrical communication with the CPU or to a local temperature sensor unit which, in turn, communicates with the CPU. Communication of the temperature sensors with the CP U may be by wireless RF signals or may be hard wired. Preferably, a tempcrature sensor is at least located at the solar pump suction pipe immediately adjacent the reservoir whereby to obtain a temperature measurement of the water exiting the reservoir. The temperature sensor is preferably a thermostat adapted to sample the temperature of the water periodically and to feed this information back to the CPU. Preferably, the temperature sensor measures the temperature of water in the reservoir in the range of 0- 100°C and the CPU governs the operation of the valve according to the reservoir water temperature measured by the sensor. ^' The temperature sensor unit may alternatively have a logic circuit able to control the operation of the valve.

The valve may be any suitable valve construction adapted to partially or wholly interrupt the flow of fluid through the water pipes connecting the solar heater to the reservoir. For example, the valve may be a rotating valve closure member that rotates against the valve scat to open or close the valve by positioning a valve channel appropriately in line in the water pipe or tube. The valve may be an in-line valve closure element that reciprocates along the axis of llow of water towards or away from a valve seat. A mechanical member may be used to move the in-line valve element, for example by rotating an asymmetrical knob that contacts a surface of the flow element to move the flow clement along the flow path. Preferably, however, the valve element is operated by an electronic device, such as a stepper motor, solenoid or other suitable motor. Particularly preferred is an electronically aclualable motor that can be controlled by the CPU. the valve may be a 3-way valve and located in the in-flow pipe to the reservoir. The solar return pipe may have at least a one way valve at its lower end to prevent baclcflow to the reservoir and to maintain a column of water through a substantial length of the solar return pipe. Preferably, the valve comprises a pair of independent valves, each located in one of the reservoir out-put pipe and the reservoir in-put pipe. Preferably, where the valve comprises two or more independent valves in the system, the operation of the valves is coordinated to ensure an unimpeded llow of water through the system, or a partially impeded or wholly interrupted flow, as required.

Water may be induced to flow through the system by means of a thermo-siphoning thcrmo-syphoning affect. Where thermosiphon is not possible due to elevation and conveelive flow a suitable pump may be attached. Where a low water temperature is measured by the temperature sensor, the CPU may cause the valve to open. to admit water llow from the heater to the reservoir. Alternatively, a high- water temperature measured by the sensor may induce the CPU to cause the valve to close to prevent water flow from the heater to the reservoir.

The heater may include a heater inlet that is in water-line connection to the reservoir and a heater outlet that is in water-line connection to the reservoir. The heater inlet may connect with a corresponding reservoir outlet positioned higher than a reservoir inlet in connection with a corresponding heater outlet, whereby hotter, less dense water will enter the reservoir low in the body of water and will tend to rise to said reservoir outlet to induce water flow through the water lines of the system. Where thermosiphon is not possible due to elevation and convective flow a suitable pump may be attached. This is particularly suited to a closed system or loop. Closed loop heating operations adapted to heat in-slab water tanks may derive sufficient solar energy for water heating for the purposes of maintaining a comlbrtablc temperature in the building. The reservoir water temperature may be built up over a period of time via a thermosiphon affect, particularly where the reservoir is an insulated in- slab water tank or array of water tan ks. The temperature sensor may he fitted to the outgoing return water line from the reservoir. 1 lie CPU may be programmed with a calculated thermal comfort cut-off point to suit a building interior whereby a valve is actuated to regulate flow cycles to maintain the reservoir water temperature at, for example, 20°C. The arbitrary temperature cut-off point may be made lower in hotter climates or seasons and higher in cooler climates or during winter peak periods.

The system may further include a pump to assist the cycle. The operation of the pump may be coordinated with the actuation of the valve to circulate water through the system. The pump may be a variety of pump types, for example such as those typically used in pool or spa filtration systems. Tt is noted (hat the pump may be required to pump water in a closed pipe system through a rise of at least 3 meters from the sub-floor reservoir to the solar heater, for example where the solar heater is mounted on the buildings' roof. The pump may effectively operate as a valve whereby to impede water flow when off and to cause water How when on, so that a separate valve member may not be necessary. However, preferably the system includes a valve separate to the pump. The pump may be located in a water-line in connection with the reservoir outlet and the heater inlet, namely the solar return line, noting that the solar heater will; typically, but not necessarily, be elevated relative to the reservoir.

The system may further include a hot water storage tank in water-line connection with a solar outlet. The hot water storage tank may be supplementary to the reservoir and may be used to store a smaller amount of water at a minimum elevated temperature, such as for supply of hot water to domestic hot water outlets, such as kitchen, bathroom and laundry fittings.

The healing of the storage tank may be supplemented by a secondary heater, such as a gas or electric heater. Thee storage tank may further be connected to mains water whereby to pressurise the storage tank and provide an uninterrupted source of water to the system, The system may also be supplied by a rain water collection arrangement, for example where rain water is collected from a roof surface and directed lo the reservoir. Cool water from non direct incident radiation facing (shaded) say south side southern hemisphere rain storage tanks can also be fed into the system for tempering .and cooling during summer when required to cool thermal mass. The gas fuelled back up for internal domestic use, optionally with mains pressure supply may be used to supplement the heat energy supplied by the solar healer to elevate the temperature of the supplementary storage lank to, for example, in contrast, where the system comprises only the solar healer and the reservoir in a closed loop, the system may be dedicated for solar heating a floor structure, such as a slab, whereby the slab temperature is maintained at, for example, 20°C The system is therefore capable of heating a house or other building during sunlight hours, preferably without any other energy input. Such a closed system could be supplemented with an overlaid hydronic system that could be used to provide supplementary heating if required. Tn this regard, it is noted that water has four times the specific heal capacity of materials such as concrete, so that such a system would be very energy efficient.

The CPU may be in the form of a computer processor or microprocessor.

Alternatively, the CPU may be, at its simplest level, a programmable logic control (PLC) unit. The PLC may be integrated within another electrical component of the system, for example the valve or temperature sensor, or may be a separate device and will he effective to actuate the valve in response to programmed predetermined temperature settings.

The solar healer may comprise anyone of a number of suitable solar healing arrangements. For example, the solar healer may comprise copper coils framed in a shallow box with a glass covering panel for ^'thermal insulation. Alternatively, the solar heater may include an array of hlack plastic tubing for a more cost-effective arrangement. The water-lines connecting the solar heater to the reservoir may be plastic piping, optionally insulated, according to standard insulation practice for solar water heated pools or spas.

The reservoir is preferably partially or wholly thermally insulated by a surrounding settablc material. The sellable materia) may be concrete or a polymeric foam material, such as polyiirethanc. Preferably, the scttable material is concrete that is cast and set around the reservoir or is cast with voids adapted to receive the reservoir. I-he reservoir may include a bladder suitable for installation in cavities that arc difficult to access. Alternatively, the reservoir may comprise a blow moulded plastic tank well known in the art. Preferably, the reservoir includes one or more plastic tanks. Still more preferably, the reservoir comprises an array or plastic tanks. The plastic tanks may be installed when the sub- floor structure is formed. Preferably, Ihe sub-floor structure comprises a concrete slab. Still more preferably, the reservoir is installed as an in-slab tank in which the in-slab reservoir is placed in position prior to filling the sub-floor area with suitable material, preferably concrete. The reservoir is preferably encased in concrete and the building floor preferably comprises an upper layer of 10-15cm of concrete above the top wall or ceiling of the reservoir. Phase Change Materials (PCM's) can be added to the reservoir storage or into the in slab. tanks in series or parallel with different heating triggers 26 deg C- 30 deg C to aid and accelerate the heating cycle and convective flow.

Where the system involves A closed loop, the circulated water need not be maintained with a hygiene regime, for example to prevent the development of Legionnaire's (by maintaining a minimum temperature of 65 "C) or other toxic conditions. Furthermore, other lluids such as vegetable oil, coolant or grey water muy be used instead of water.

BRIEF DESCRIPTION OF THE DRAWINGS

The- invention may be better understood from the following non-limiting description of preferred embodiments, in which:

Figure 1 is a schematic diagram of a solar in-slab heating system according to one aspect of the invention;

Figure 2 is a schematic diagram of a solar in-slab heating system with storage and gas fired back up according to a second embodiment of the invention; and

Figure 3 is a schematic diagram of a thermal regulating in-slab and external tank combination system according to a third embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention.

In a first embodiment, a solar heating system 1 comprises a closed loop comprising a solar water heater 10 in fluid line communication or connection with a reservoir 50, the connection comprising a solar return water pipe 20 and solar output pipe 22. The system 10 further includes a temperature sensor 30 installed in the return pipe 20 immediately adjacent the reservoir 50, and a 3-way valve 40 used to control the water flow in the output pipe 22. the lluid maybe water or any lluid that may have preferable properties.

The solar water heater comprises of cither evacuated tube or at least one array or coil of black polyvinyl chloride (PVC) pipe laid in conventional fashion on a roof surface, preferably with the roof inclined to maximise exposure to solar radiation. The solar water heater has a secondary outlet pipe 24. close to the return pipe 20 and inlet 12 that enables the passage of water through only a portion of the maximum . length of the solar water heater tubing 16 as an option, for example, during periods of extremely high solar radiation levels.

The valve 40 is a solenoid valve electrically connected to the temperature sensor 30 by hard wiring 32. Alternatively, a radio signal from a transmitter associated with the temperature sensor 30 is sent to a receiver associated with the solenoid valve 40 to control, the operation of the latter. The temperature sensor 30 includes a programmable logic circuit (PLC) 34 to enable control of the operation of the valve 40 by cither setting a desired temperature range or by a timer. For example, where it is desirable for the temperature of the water in the reservoir 50 to be tnaintaincd in a range of 20-23ºC, the PI ,C 34 may be set to actuate the valve 40 to the 'W position when the water temperature drops below 20'C and "closed" when the water temperature rises above 23ºC. Alternatively, where the system 1 is to be controlled by a timer and the heating effects of the solar water heater 10 on the water in the system 1 is predictable for a certain period of exposure, the PLC 34 may actuate the valve 40 to the open position during the peek sunlight period, for example, between the hours of 1 lam and 3pm.

llie temperature sensor 30 may include a temperature sensor inserted into a hole formed for this purpose in the wall of the return pipe 20. Grommets may be provided in the hole and then a small plastic cup or pocket may be inserted in the grummet. The sensor 30 may then be installed in the pocket and electrically wired to the valve 40.

The reservoir 50 comprises an array of in-slab plastic water tanks or pods 52 in communication with each other by virtue of a series of interconnecting pipes 54. ^'lhe pods 52 are prc-laid in the site excavated in preparation for laying of a slab 56. The slab is then poured around the pods 52 and interconnecting pipes 54 and into the void defined by the pods 52, the interconnecting pipes 54 and bordering form work 58 and allowed to set to form a floor surface having a thick layer of concrete of between 10- 15cm between the floor surface and the upper scaling or wall of each pod 52.

Reinforcement in the form of metal grid, rods, mesh or beams may support the slab 56 or may be embedded in the concrete, around, above and/or below the pods 52, optionally supported by bar chairs or like devices, during the pour.

As the system 1 is a closed loop, the water contained therein docs not need. to be hygienically maintained and can be maintained in a moderate temperature range of between 17-25'C (preferably 20-23ºC) whereby to heat the slab 56 to this approximate temperature range. As the system 1 is scaled the fluid of the system 1 (preferably water) substantially fills the voids with minimal air pockets to provide a continuous line of water throughout the system 1 . The temperature and pressure differentials throughout the system 1 promote circulation of the water in a single direction I), either by conveclive flow or are pumped preferably by a solar assisted pump namely clockwise in the embodiment shown in Figure 1.

Referring to Figure 2, there is shown a system 100 also including a solar hot water heater 110 and a reservoir 150 similar to that shown in the embodiment in Figure 1. However, the system 101 is not closed and includes a supplementary water storage unit 160 connected to a mains water supply and a computer processing unit 170. The CPU 170 is programmable by a user to control the operations of a water pump 180. a valve 140 and a gas healer 190 used to heat the supplementary water storage tank 160. The pump 180 may be electrically hard wired to the CPU 170 by electrical connection 172 or may communicate therewith by a radio transmitter receiver arrangement. The gas heater 190 may be electrically connected to the CPU 170 by hard wire 174 or by radio communication. The CPU 170 may similarly be connected to a second temperature sensor 136 in the supplementary water storage lank 160.

The CPU 170 is programmable to specify the temperature range L75 shown on a display 177T for the reservoir 150 and the temperature range 176 shown on the display 177 for the supplementary water storage tank 160. In response to the dropping of the temperature of the reservoir 150 water as measured by the reservoir temperature sensor 130, the CPU 170 will activate the pump 180 and open the valve 140 to permit the How of water from the pods 152 through a rotum pipe 120 to the solar hot water heater 1 10 and out through the output pipe 122 back to ^'the reservoir 150. This condition remains until the periodic temperature measurement (for example, carried out at one or ten second intervals or every hour) carried out by Ihe temperature sensor 130 reaches the maximum temperature in the programmed range (lor example 26'C) as shown in the CPT 1 display 177. On reaching the maximum temperature in the range 175, the pump 180 is switched off and the valve 1.40 is simultaneously ihoved to the shut position. Independently of the pump 180 and the valve 140 operation, the second temperature sensor 136 in the supplementary storage tank 160 controls the water temperature in the supplementary storage tank 160 by providing feedback to the CPU 170 in manner similar to that described in relation to reservoir temperature sensor 30, 130. The CPU 170 controls the operation of the gas healer 190 or, alternatively, the gas heater 190 is controlled by a localised logic circuit in a manner similar to a conventional hot water service. The supplementary water storage tank 160 is supplied by mains water 162 whereby the water supplied to the building's tap fittings 164 is under mains pressure. To minimise the gas fuel used by the supplementary water storage 160, water is diverted from the reservoir 150 loop and output pipe 122 to the solar hot water heater output pipe 126 to keep the

supplementary hot water lank 160 topped up. In this connection, the supplementary hot water tank 160 may include a float level indicating device that controls a local valve 166 to regulate the water level in the supplementary hot water tank 160.

The system 101 may be supplied by a rain water collection arrangement 185 typically mounted on the roof of the building and adapted to feed rain water as available into the system via rain water pipe 128. Mains water 162 may be used lo supplement the supply of water from the rain water collection arrangement 185.

The reservoir 50, 150 may be augmented by a hydroponic system 200 adapted to more effectively transfer heat from the reservoir 50, 150. The hydroponic system 200 may be located above the pods 152 in the slab 156 and may redirect water from the reservoir 50,150 to the hydroponic system 200 or may include a heat exchanger 210 that transfers heal to or from the reservoir 50, 150 to the floor surface immediately above the hydroponic system 200. Referring to Figure 3. there is shown a thermal regulating system comprising radiant cooling tanks 310 preferably located on cooler shaded exteriors of a building to be thermally regulated by the system. The tanks 310 are made of conducting material such as steel which will rapidly lose temperature at night time and can be used to supplement the cooling of the in slab reservoir 1.50 in summer or conversely lo heat the reservoir 150 in wintertime. As with the first and second embodiments shown in Figs. 1 and 2, the system 300 also includes thermal healing means in the for of solar panels aor solar heat collectors, such as black heat absorbing piping associated with the solar water heater 110. The fluid llow in the system 300 is controlled by the the use of a pair of control valve sl40a,b or a pump 180 as in Fig. 2.

The systems have been described with reference to Figs. I - 3 including a heating cycle in which the heating source would most preferably be evacuated tube rather than black plastic (pool style pipe heating).

With reference only to Fig. 3, the cooling component is incorporated the slab thermal regulation technology. Radiant night cooling in inland dry climates such is found in Canberra is very effective. For example, in Canberra the overnight ininiinimi lemperaLure averages 13ºC (and commonly down to 0 - 3"C in summer so south side shaded metal tanks 310 (and the equivalent in the northern hemispehere being tanks 310 on the north side) will lose heal to the atmosphere overnight very effeclively and be quite cool. This provides a cool water source that can be effectively solar pumped into the in- slab reservoir 150 via solar pumps 180 first thing in the morning to cool the slab 150.

The pump 180 is preferably a photovoltaic pump. Pipe 54 is cast in situ and used to communicate the fluid from the pods of the in-slab reservoir 150 to the healing component in solar water heater 1 10. The system 300 thus comprises a cold mass heat exchange system in which warm water of the pods is replaced with cooled water (overnight) Irora the tanks 310 to achieve a stable thermal mass. Water is pumped around the closed system 300; Closed to the outside of the system 300, the warm water in summer is removed from the pods 150 and sent to the tanlc 310 for cooling at night. IXiring the day, the pod 150 water heats up, as does the water on the external tanks 310. The healing element 110 preferably comprises a pair of banks of about 40 evacuated tubes. The cooling component preferably comprises a pair of 5000T. tanks

In the hotter months, the valve I40a,b operation may be used to shut off the heating system 1 10. And by corollary, the cooling system 310 may be shut off in the cooler months. The valves.140u,b may be bullerlly or other valves suitable for the purpose and used to isolate or decouple different parts 1 10,310 of the system 300 from the pods 150.

Throughout the specification and claims die word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be laken lo indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.

Oricntational terms used in the specification and claims such as vertical, horizontal, lop, botlom, upper and lower are to be interpreted us relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the pods 52, 152 lowennost. It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.

Claims

The claims:

1. A temperature regulating system for regulating the temperature in the living spaces of a building including:

a sub-floor fluid reservoir located in, under or on a cast and set material forming part of the floor of said building; utilised for varying the ambient temperature of said building;

a solar heater mounted on or in association with said system ;

a temperature sensor to measure Lhe temperature in said reservoir; and at least one valve to control fluid flow along a line in communication with said reservoir and said heater to regulate the temperature of the fluid within the reservoir.

2. A temperature regulating system according to claim 1, further including a radiant cooling system including a radiant cooling tank utilised as a cooling supply source.

3. A temperature regulating system according lo claim 1 or 2, wherein said lluid is water and said temperature sensor measures the temperature of^* water in said reservoir in the range of 0 to 100 ºC and a computer processor governs the operation of said valve according lo the reservoir water temperature measured by said sensor.

4. A temperature regulating system according to any one of claim 1 to 3, wherein a low water temperature measured by .said sensor eaascs said valve to open to admit water flow from said heater to said reservoir and a high water temperature measured by said sensor causes said valve lo close to prevent water flow from said heater to said reservoir.

5. A temperature regulating system according lo claim 2, wherein the lank is shaded and a said sensor allows cooler water from the shaded tank to replace waler in the in slab of sub-floor reservoir.

6. A temperature regulating system according to claim 3, wherein said heater includes a healer inlet in waler line communication lo said reservoir and a heater outlet in water line communication to said reservoir.

7. Λ temperature regulating system according to claim 2, wherein the cooler tank provides a source of storage to feed and replace water lxom the inslab reservoir.

Λ temperature regulating system according to claim 2, wherein pumping of cooled water may be done by a solar powered pump.

A temperature regulating system according to claim 5, wherein said heater inlet communicates with a corresponding reservoir outlet positioned higher than a reservoir inlet in communication with a corresponding heater outlet, whereby hotter less dense water will enter said reservoir low in the body of water in said reservoir and will tend to rise to said reservoir outlet to encourage water How through (he water lines of the system.

A temperature regulating system according to claim 1, wherein said system includes a pump for moving the water through the system and suid pump is effective to operate as said valve.

A temperature regulating system according to claim 10, wherein said pump is located in a fluid line in communication with said reservoir outlet and said healer inlet.

A temperature regulating system according to claim I , wherein said fluid is water and the system further including a hot water storage tank in water line communication with a second heater outlet of the heater,

A temperature regulating system according to claim 12, wherein heating of said hot water storage tank is supplemented by a secondary heater.

A temperature regulating system including the addition of appropriate Phase Change Materials (PCM's) can be added to the reservoir storage or into the in slab tanks .

A temperature regulating system, wherein the PCMs arc in scries or parallel with different heating triggers 26 deg C- 30 deg C to aid and accelerate the heating cycle and convcctivc flow.

A temperature regulating system according to claim 13, wherein said secondary healer is a gas or electric heater and said hot water storage tank is connected to a mains water source to pressurise said system.

A temperature regulating system according to claim 1, wherein said system circulates water by a thcrmosiphon action.

18. Λ temperature regulating system aceording to claim 1 or 17, whciicin said system is a sealed and closed loop heating system,

19. A temperature regulating system according to claim 1, wherein said reservoir comprises an array of interconnected in-slab water tanks

20. A temperature regulating system according to claim 19, wherein said tanks are thermally insulated by surrounding cast and set material.