WO2010103255A2

WO2010103255A2 - Solar panel for water heating

Info

Publication number: WO2010103255A2
Application number: PCT/GB2009/000625
Authority: WO
Inventors: David Osborne
Original assignee: David Osborne
Priority date: 2009-03-09
Filing date: 2009-03-09
Publication date: 2010-09-16
Also published as: WO2010103255A3

Abstract

A solar panel comprising of heat exchanger made of thin anodised black aluminium sheet and plastic sheet to entrap sunlight is attached to water tank and act as source of heated water. The heat exchanger is contained in UV protected black plastic tray which is tilted. The solar panel which is cheap and easy to assemble provides water heating for usage in undeveloped and developing countries.

Description

PATENT SPECIFICATION

SOLAR PANEL FOR WATER HEATING

SUMMARY OF INVENTION:

This invention provides a simple water heated system which supplies continuous supply of heated water in all weather conditions, during day and night time utilising solar energy via solar panel, conventional emmerser heater powered by battery or mains supply and wind turbine generated power..

BACKGROUND:

Solar heating water systems have been developed and are described below in detail: Solar water heating systems as disclosed by WO2007053859 and US6014968 describe heat exchangers which primarily consists of a heat absorbing pipe or pipes which are connected to a water tank and utilizes solar energy for energy supply. US6014968 discloses a heat exchanger comprising of a number of heat absorbing pipes which are surrounded water cooling return pipes and is aimed at industrial applications. WO2007053859 is aimed at low cost users and is inexpensive and discloses solar water-heater which includes a water storage tank connected to heat absorbing pipe and an outlet of which connected to hose pipe for supplying heated water to a user. US6119682 discloses solar energy powered, thermosyphon-circulated water heater and storage device comprising: a flat, tilted solar radiation absorber panel and an insulated hot fluid storage tank and connecting pipes, but also enclosed is electric immersion heater. A solar energy powered water heater and storage device. In essence it provides a low- profile, flat-plate solar energy collector holding a fluid which is heated and circulated to an integrated, insulated hot fluid storage tank, the hot fluid in turn heats line pressure water passing through an extended length, heat-exchange piping circuit incorporated within said tank, in conjunction with a supplementary, electric water-heating means. CN 1837711 discloses split type solar water heater comprising of heat collector formed by glass vacuum tubes, a water tank, an inlet and outlet heat collector tubes, a closed electromagnetic valves and a computer control plate for controlling said cycle system. WO9531677 describes a heat exchanger for vacuum systems, especially for use as a flat solar absorber or a wall or roof panel, with an envelope for the heat exchange medium sealed and core which has narrow flutes, grooves or channels on the heat-exchange surface. US4261333 describes a solar heating panel apparatus which has a supporting base with a plurality of elongated heat exchanger members mounted to the base. Each heat exchanger is operatively connected to one end of an adjacent heat exchanger to provide a continuous path through the heat exchangers from a fluid input to a fluid output. Each heat exchanger has a hollow centre core having a passageway running spirally around the centre core and uses the centre core as one wall of the spiralling passageway. US4159708 discloses a solar energy collector and heat exchanger for use in a solar energy system that provides space heating and preheating of water for a building or residence. The discloser is aimed at improved solar energy collector and heat exchanger of the type which comprises a radiation collecting surface enclosed within a housing which surface absorbs the solar energy of the sun and transfers it to a portable storage medium. An improved solar energy collector and heat exchanger includes baffles in the housing that define a first serpentine channel beneath the surface and a second serpentine channel above the surface. Air inlet and air outlet parts in the housing communicate with both the first and the second channels. A fluid system having an inlet and an outlet is provided. A fluid system includes an array of interconnected tubes mounted on the solar absorption surface. CN 1294284 discloses a photoelectric and passive photothermal appliance for greenhouse. Its solar battery is connected with accumulator or inverse transformer of electric network to provide electric energy to the electric appliances. Its solar heat collector is linked with air purifier and heat exchanger for regulating air quality and indoor temp. A cold water tube passes through heat exchanger for providing hot water. JP56146958 discloses a thin box made of plastic plate and aluminium plate with enclosed air to form heat exchanger and water pipe is connected to this transmit heat. This system requires heat to be transmitted via exchanger to water pipe. This invention is aimed at an inexpensive and simple system to provide households with means to heat water utilizing solar energy. The simple system is easily assembled and easy to maintain making it affordable to poor households in developing countries. Unlike above described prior art, this system heats water by solar energy. In essence, it provides an inexpensive, easy to assemble system which heats water. Also, the system is designed such that it supplies continuous supply of heated water.

Summary of Invention

The main embodiments of this invention are as follows: This invention provides a simple water heated system which supplies continuous supply of heated water in all weather conditions, during day and night time utilising solar energy via solar panel, conventional emmerser heater powered by battery or mains supply and wind turbine generated power.

A simple solar panel system to heat water at very low cost 86 A solar panel comprising of black anodised aluminium heat exchanger

87 contained in an encloser made of insulating black plastic container with

88 sunlight transmitting clear plastic sheet when connected to closed water

89 tank provides means to heat water at very low cost 90

91 Another embodiment of the invention is a solar panel system entraps

92 solar energy and heats water to Δ25°C to Δ85°C, preferably Δ25°C to

93 Δ45°C, and generate via (a) clear plastic panel/sheet, (b) heat

94 absorbing black anodised aluminium sheets, (c) black body effect, d)

95 and green house effect. A solar panel consisting of heat exchanger

96 made of sheet of heat absorbing black anodised or anodised aluminium

97 sheet with emissivity > 0.6, preferably 0.9-0.95, and a clear plastic

98 sheet or glass panel. The solar panel made of black anodised

99 Aluminium heat exchanger and sun entrapping clear plastic sheet is

100 titled at angle is connected to water tank with sealed lid to generate

101 closed system. 102

103 Another embodiment of the invention is a solar panel system heat

104 exchanger is made of black anodised plain thin sheet with fins to

105 increase the surface area for heat absorption 106

107 Another embodiment of the invention is a solar panel system heat

108 exchanger is made of black anodised ribbed thin sheet to further

109 increase the surface area for heat absorption 110

111 The black anodised aluminium has emmissivity of > 0.6 -0.95 to

112 increase heat absorbing capacity. 113

114 The black anodised aluminium has emmissivity of preferably 0.8 -0.95

115 to increase heat absorbing capacity. 116

117 The heat exchanger has emmissivity, absorbance of 0.6-0.98,

118 preferably 0.85-0.98. 119

120 The anodised aluminium has enhanced hardness by 10-20 times, with

121 enhanced durability and lifespan of 20 years 122

123 A Continuous heating of water through solar energy in heat exchanger

124 occurs which it flows back to the water storage tank through the outlet

125 pipe. 126

127 A UV protected black plastic moulded tray is used provide insulative,

128 black body and greenhouse effect for the solar panel 129

130 A clear plastic or glass panel provides means of sunlight transmittance

131 and greenhouse effect for the solar panel 132

133 Another embodiment is use of emmerser heater to keep water heated

134 at night time or in absence of sunlight 135

136 Another embodiment is use of emmerser heater to keep water heated

137 at night time or in absence of sunlight which is powered by battery and

138 transformer 139

140 Another embodiment is use of emmerser heater to keep water heated

141 at night time or in absence of sunlight which is powered by electricity

142 mains and transformer 143

144 Another embodiment is use of emmerser heater to keep water heated

145 at night time or in absence of sunlight which is wind turbine.

146 * DESCRIPTION

Detailed Description:

147 Figure 1 : Schematics of water heating system

148 Figure 2: Heat exchanger configuration

149 Listed below are semantic of numbering:

150 Figure 1

151 1. Moulded tank 152 2. Aluminium Heat exchanger 153 3. 12 volt battery 154 4. 12v-240v Transformer 155 5. Emmerser 156 6. Wind turbine 157 7. light supply 158 8. Plug supply 159 9. raised floor to incorporate panel 160 10. 2mm polycarbonate sheet 161 11. Turbine head with vane

162 163 Figure 2 164 12. Aluminium panel

165 12b Aluminium fins

166 12c Ribbed surface

167 Figure 1 show that water heating system is made of rotationally

168 moulded UV protected water tank (1). The water tank is made of black.

169 4 Eyelets at each corner at the base of the tank which allows for

170 connection to the ground or Roof. This water tank is attached to one

171 moulded shape plastic frame into which Aluminium heat exchanger (2)

172 is inserted or placed. The heat exchanger is made of Black anodized

173 Aluminium (metal sheet). The black anodized Aluminium sheet has 174 emmissivity > 0.8 to 0.98, preferably 0.9 to 0.98 and hardness of 10-20

175 times > unanodised Aluminium with enhanced durability and 20 year

176 lifespan. Typical Aluminium hardness is 150 MPa. The heat exchanger

177 has dimensions of 900mm long, 700 and 25mm in height (12). The heat

178 exchanger metal sheet is 3mm Aluminium plate with fins(17/18)at depth

179 of 25mm long and equally spaced allowing a 10mm recess (12b)

180 around the whole panel as shown in Figure 2. Preferably this could

181 have elliptical surface - wave formation (12c) which increases surface

182 area and helps diffuse the light to the panel. This results in higher heat

183 absorption capability. The top surface of the frame is made of 2mm

184 thick plastic sheet, which preferably is made of polycarbonate sheet

185 (10). 2mm polycarbonate sheet of clear plastic attached on top surface

186 to the enclosed area of the frame eliminates wind chill. The heat

187 exchanger has a gap of 54mm between heat exchanger surface and

188 the polycarbonate sheet. A 2mm Plastic sheet has flat side having

189 down indent to create rigidity, air tight lid to emit wind-chill. The

190 dimensions of plastic frame are: Length 1.4m, Width 800mm, Height

191 230mm at the higher end attached to water tank and the height tapers

192 to 80mm tilting the heat exchanger to 10-20 degree angle. The inlets of

193 the water tank are formed to the lower end of the heat exchanger and

194 outlet to the water tank from the higher end of the heat exchanger.

195 The floor pan is raised in the panel part of the mould to ensure a 25mm

196 gap to provide a recess under the heat sink. 197

198 The Studs that allow connection to the tank will be stainless steel to

199 ensure no sacrificial corrosion will take place. The metallic plate

200 exchanger will be pushed against by the water pressure under the uv

201 protected polyethylene creating a tightness giving good conduction

202 between surfaces that will allow heat to transfer into the water. 203

204 The clear polycarbonate sheet to entrap sunlight coupled to black

205 Aluminium panel made of ribbed or plane surface and having fins forms

206 basis of a solar panel. This solar panel traps suns energy in very 207 efficient manner. The water flow in Aluminium finned panel. Utilising the

208 suns energy heat builds up in the tank allowing the heat circulation to

209 start. There is a replacement panel excluding 2mm polycarbonate sheet

210 to provide with a PV solar panel overlaying the Aluminium sheet

211 supplying power to a battery pack (3) with a step up transformer (4).

212 There shall be a boss in which an emmerser heater (5) can be screwed

213 into which will run on the suns energy produced and collected during

214 the day. This will only work at night to keep the water warm. Standard

215 12 volt battery (3) basically a car battery with step up transformer or

216 12volt light. A power source (8) can provide electricity for light domestic

217 use (7). A secondary power source is achieved with connected wind

218 turbine (11 ) at the highest point of the tank (6). This will provide

219 additional power in the form of kinetic energy. This power will be stored

220 within the battery like the PV solar so that in the evening when the sun

221 goes down the battery can still be charged if there is a slight wind.

222 Insulation- the tank will be insulated with a polyurethane foam which

223 itself is waterproof 224

225 The invention relates to a self standing passive solar heat exchanger

226 for use to heat hot water utilizing solar energy to provide households

227 with a simple method to heat water. The solar unit is easy to install on

228 a roof flat preferable or on the ground. The system provides many

229 households with an affordable system with a long working life. In

230 addition, the solar exchanger combined with closed flow system

231 provides means of purifying/distilling water. Henceforth, solar panel

232 attached to water tank functions as water heating system. This system

233 has added advantage that it is continuously maintain heated water via

234 emmercer heater powered by battery or maybe direct Mains electricity

235 supply and transformer e.g. at night time or when cloudy weather. In

236 addition, a wind turbine also supplies additional power and would be

237 most suitable at night time

238 The schematic of water heating and is shown in Figure 1. A water tank

239 (1) which can be of any shape e.g. square, round or square has a 240 closed Nd. The lid is preferably of sealed fitting type so it is air tight.

241 Alternatively it can be of lose fitting if system is to be only used for

242 water heating. The water tank can hold 20-200 litres and preferably 100

243 litres. The tank is filled with water via water hose, bucket or a tap. The

244 plastic tray is titled at an angle of 5 to 90 degrees, preferably to 10-25

245 degrees so the solar heat transmitted via solar panel made of plastic

246 sheet, air buffer and black anodised aluminium and entrapped in and

247 absorbed by aluminium panel heat exchanger to heat water,

248 The inlet of water tank attached to the lower end of heat exchanger and

249 outlet of heat exchanger attached to higher end of water tank enhances

250 and accelerates heating of water in tank via convective flow.

251 Black anodising, high conductivity of Aluminium and higher emmissivity

252 allows effective higher heat absorption to heat the water providing the

253 highest source of solar energy.

254 The water storage tank (1) can be made from black plastic materials

255 usually polypropylene.

256 A typical size of 60-100 litres within the tank allows 2-10 litres in the

257 heat exchanger system allowing a total capacity of 62-110 litres. This

258 capacity can easily be varied to suit the needs smaller or bigger.

259 The water heating system is flat based to allow the system to be placed

260 on a roof or on the ground or of a said structure.

261 The tank can be cylindrical or rectangular with a lid this is used to

262 protect the water from debris and foreign bodies.

263 The tank may be from sized according to water demand for a typical

264 house of 4 inhabitants may require 100 litres whereas another

265 household of 6 inhabitants may use 160 litres this can be varied to suit.

266 The tank may be insulated using spray foam or an insulating blanket.

267 The storage tank is filled by hand through an opening in the tank

268 however an automatic filling device may be applied if required i.e. if it

269 installed on the roof

270 A filter may be fitted across the tank opening to filter out any debris

271 from incoming water, i.e. plant material or insects 272 The nature of the plastic is to act as an insulator. This allows the UV

273 protected tray to insulate the heat exchanger to ensure a constant

274 temperature once heated by solar energy.

275 Distance between the clear plastic sheet and the heat exchanger may

276 be 5-100mm, preferably 54mm to minimise shadow castings over the

277 course of the day as well as a reduction in volume to heat.

278 A spigot is fitted to the tank to allow hot water to be drawn off manually

279 without removing the lid. This spigot can be adapted for roof

280 installations to allow the system to be connected to domestic plumbing.

281 This system allowed temperature of water to increase by Δ25-80°C,

282 preferably by Δ25-45°C. The increase in water temperature was also

283 dependent on temperature of sunlight. Outside temperature of 20-25⁰C

284 enabled water temperatures of 45⁰C attained at open outlet

285 configuration within 2-8 hours, preferably 4 hours . Outside temperature

286 of 20-35⁰C enabled water temperatures of 65⁰C attained. Use of

287 emmerser heater and wind turbine enhances the temperature rise and

288 decreases time duration. Combination of all system allows continuous

289 water heating system. The metallic heat exchanger which is covering

290 1mm of polyurethane plastic, secured in position by securing band. The

291 plastic is as a seal for water leakage

292 293

Claims

294 1. This invention is a simple low cost single unit water heated system which

295 provides supply of heated water utilising solar energy via solar panel

296 which comprises of;

297 Single unit comprising of tilted metallic heat exchanger in-situ

298 connected to a water tank and an insulating black plastic container with

299 clear plastic sheet at top side, in which a continuous heating of water

300 occurs by combination of;

301 a. sunlight transmitted through clear plastic sheet,

302 b. heating by energy absorbance by the black metallic heat exchange,

303 c. black body effect and insulating effect of black plastic container,

304 d. continuous flow within single unit comprising of titled heat

305 exchanger in-situ connected to water tank,

306 e. UV protected single unit black plastic container/tray and water tank

307 with anti-microbial properties. 308

309 2. A system of claim 1 , which provides continuous supply of heated water in

310 all weather conditions, during day and night time utilising solar energy via

311 solar panel, if supplemented by conventional heater or stored generated

312 power.

313 3. A system of claim 1 & 2, which is a solar panel system entraps solar

314 energy and heats water to Δ25°C to Δ85°C, preferably Δ25°C to

315 Δ65°C, and generated via (a) clear plastic panel/sheet, (b) heat

316 absorbing black metallic sheets, (c) black body effect, d) and green

317 house effect; a solar panel consisting of heat exchanger made of heat

318 absorbing metallic sheet with emmissivity > 0.6, preferably with heat

319 absorbing black anodised aluminium or < 1mm sheet metal with

320 emissivity > 0.8-0.95, and a clear plastic sheet or glass panel

321 4. A system of claims 1 & 2 where the solar panel made of metallic heat

322 exchanger and sun entrapping clear plastic sheet and is titled at 5 to 95 323 degree, preferably at 10-25 degree and preferably at azimuth angle is in-

324 situ connected to water tank with sealed lid and black plastic tray or

325 container as a single closed unit to generate continuous heat transfer

326 and water flow within the unit.

327 5. A product of claim 3, which is a solar panel system heat exchanger is

328 made of metallic sheet with fins, preferably black metallic thin sheet with

329 fins and preferably black anodised plain thin sheet with fins to increase

330 the surface area for heat absorption

331 6. A product of claims 3 & 5, which is a solar panel system heat exchanger

332 is made of metallic ribbed thin sheet, preferably black metallic ribbed thin

333 sheet and preferably black anodised ribbed thin sheet to further increase

334 the surface area for heat absorption.

335 7. A method of claim 3, 5 & 6, where the metallic sheet has emmissivity of

336 > 0.6 -0.98 to increase heat absorbing capacity.

337 8. A method of claims 3, 5-7, where the black anodised aluminium has

338 emmissivity of preferably 0.8 -0.98 to increase heat absorbing capacity.

339 9. A method of claims 3 to 8, where the heat exchanger has emmissivity,

340 absorbance of 0.6-0.98.

341 10. A method of claim 8, where the anodised aluminium has enhanced

342 hardness by 10-20 times, with enhanced durability and lifespan of 20

343 years.

344 11. A method of claims 1 , 2 & 4 where the continuous flow of heated water

345 occurs within single unit as function of:

346 a) in-situ connection between heat exchanger, water tank and plastic

347 tray or container

348 b) heat exchanger at titled angle.

349 12. A method of claims 1 & 2, where the UV protected black plastic moulded

350 tray is used to provide insulative, anti-microbial properties, black body

351 and greenhouse effect for the solar panel.

352 13. A method of claims 1 , 2, 11 & 12, where single heating unit with top light

353 transmitting plastic sheet and metallic heat exchanger . The uv

354 protected plastic single piece is cast in rotational moulding process.

355 14. A method of claims 1 & 2, where a clear plastic or glass panel provides

356 means of sunlight transmittance and greenhouse effect for the solar

357 panel.

358 15. A method of claims 1 & 2, which uses any conventional heater to keep

359 water heated at night time or in absence of sunlight.

360 16. A method of claims 1 & 2, which uses or utilises conventional heater to

361 keep water heated at night time or in absence of sunlight which is

362 powered by generated stored supply.

363 17. A method of claims 1 & 2, which uses or utilises conventional heater to

364 keep water heated at night time or in absence of sunlight which is

365 powered by electricity mains and transformer.

366 18. A method of claims 1 & 2, which uses or utilises conventional heater to

367 keep water heated at night time or in absence of sunlight which is

368 powered by kinetic energy source.