SOLAR WATER HEATER WITH GLAZED FLAT-PLATE COLLECTOR

Abstract

The present invention relates to a solar water heater (SWH) for producing hot water for domestic use, said SWH is inspired from the thermosiphon SWH to manufacture an SWH more efficient in winter and in summer. It is made up of two hot water storage tanks (17) (22) mounted in series in order to have an operating temperature as stable as possible, equipped with a guidance system for heating incoming cold water by passing through the collectors before entering the hot water storage tank (25-a) (25-b), a solar collector receiving solar radiation through its twin transparent faces (35) (36), stainless steel sheet mirrors that reflect the solar radiation applied to the collector through its rear transparent face (36) and a low energy consumption integrated circulator for gaining heat by cancelling out load losses that characterize the resistances to the passage of water in the SWH circuit (29).

Claims

1. Solar water heater (SWH) is used to heat water by solar energy for domestic use containing: A domestic hot water storage part consisting of two storage tanks mounted in series (17) (18) (22) instead of a single tank (commonly used), to ensure the stability of the hot water temperature during the use, the hot water leaving the collector (19) enters the first tank (17) through its ‘cold water inlet’, the second tank (22) is supplied with water by the ‘hot water outlet’ of the first tank (18), the ‘hot water outlet’ of the second tank (21) is reserved for use. The collector (20) is supplied with cold water to be heated by the ‘cold water inlet’ (27) of the second tank. A heating part consisting of a solar collector (20) mounted in series in a closed loop with the two storage tanks, the collector is glazed in his two faces (35) (36), front face towards the sun glazed with glass (35) and back side with resistive and transparent plastic (36) to receive more solar radiation on the same absorbing surface and thus increase its temperature quickly and therefore faster water heating with less absorbing surface. A stainless steel sheet mirrors (40) (41) fixed on the system support (FIG. 7) to radiate the rear face of the collector, the fixed position and angle of the mirrors take into account position and angle of the collector (winter and summer position) and the relative rotation of the sun around the earth during the day and along the days of the year so that the radiation applied to the rear face of the collector is maximum during winter. A low energy consumption circulator integrated into the collector for gaining heat by cancelling out load losses that characterize the resistances to the passage of water in the SWH circuit (29) A guidance system to heat incoming cold water by passing through the collector before entering the storage tank (25-a) (25-b) to maintain the heat of water inside it. A support where the system (tanks+collector+mirrors) are fixed (FIG. 7).

2. Solar water heater according to claim 1, wherein the two tanks (17) (22) are mounted in series and connected in closed loop with the SWH circuit (FIG. 3), the second tank supplied by the hottest water of the first tank located in its upper part (17) (23) allowing a more stable supply of hot water for use.

3. Solar water heater according to claim 1, wherein the solar collector is characterized by an absorbing surface consisting of a thin sheet of aluminum bent along its length (31) such that the tubular circuit (32) is housed in the latter and that the connection between the absorbing surface and the tubular circuit is ensured by housing and fixing with iron wires and screw nut (33).

4. Solar water heater according to claim 3, wherein the solar collector is characterized by a twin transparent faces radiation receivers (35) (36) on the same absorbing surface, front face direction of the sun (35) is glazed with glass and the rear face (36) with resistive and transparent plastic.

5. Solar water heater according to claim 1, wherein a stainless steel sheet mirrors fixed to the support of the system to collect and reflect the radiation towards the rear transparent face of the collector (36).

6. Solar water heater according to claim 1, wherein a low energy consumption circulator is integrated in the collector (29), it plays a dual role, on one hand it ensures the circulation of hot water between the collector, the first tank and the second tank, on the other hand, it saves thermal energy by canceling the pressure drops that characterize the resistance to the passage of water in the water heater circuit of SWH.

7. Solar water heater according to claim 6, wherein the circulator is controlled by an electrical circuit consisting mainly of a microcontroller, two temperature sensors and a transistor (FIG. 11) to manage heated water between storage tanks and the collector, when the temperature in the collector is above the temperature of the second storage tank the circulator is actioned or else it is stopped.

8. Solar water heater according to claim 1, wherein the input water (26) to the SWH (often cold water) that replace the output hot water (in case of domestic use) is characterized by the passage through the collector for heating before entering the tanks (where water is thermally insulated) instead of entering directly to the tanks (commonly used), this guidance system is provided by the assembly of the two non-return valves (25-a) (25-b) and is intended to maintain the temperature of the water in the tanks in case of use during the presence of the sun.

9. Solar water heater according to claim 1, wherein the support serving for the installation of the various components of the SWH (tanks+collector+mirrors) is consisting of two separated sub-support made with Aluminum Angle, one is used to fixe tanks and mirrors and the other to fixe collector, giving more flexibility to adjust manually and easily the collector position in order to get radiation into his back side permanently along the days of the year (FIG. 7).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] 1—Sanitary cold water inlet [0058] 2—Sanitary hot water outlet [0059] 3—Hot water storage tank [0060] 4—Collector [0061] 5—Solar radiation [0062] 6—Collector coil [0063] 7—Tank Coil [0064] 9—Joint [0065] 8—Collector inlet [0066] 10—Glazing [0067] 11—Absorber [0068] 12—Insulation [0069] 13—Metal frame [0070] 14—Conductive thermal transfer. [0071] 15—Conductive black paint [0072] 16—Laser welding [0073] 17—First hot water storage tank [0074] 18—Hot water connection link of the first tank with the second tank [0075] 19—Col lector outlet to the first tank [0076] 20—Glazed flat-plate collector [0077] 21—Outlet for domestic use [0078] 22—Second hot water storage tank [0079] 23—Hot water position at thermal equilibrium [0080] 24—Cold water position at thermal equilibrium [0081] 25-a—Non-return valve [0082] 25-b—Non-return valve [0083] 26—Sanitary cold waterinlet [0084] 27—Second tank outlet to be heated by the collector [0085] 28—Collector inlet [0086] 29—Circulator [0087] 30—Absorber [0088] 31—Tubular shape curves [0089] 32—Copper coil [0090] 33—Coil/absorber fixation with wire and screw nut [0091] 34—Primary wooden frame [0092] 35—Glazing front face right to the sun with glass [0093] 36—Rear glazing in plastic [0094] 37—Secondary aluminum frame [0095] 38—Direct reflection mirrors and tank support [0096] 39—Recovery mirror and collector support [0097] 40—Direct reflection mirrors [0098] 41—Recovery mirror [0099] 42—Collector [0100] 43—Solar radiation [0101] FIG. 1: Thermosyphon glazed flat-plate SWH types and its various components [0102] FIG. 1-A: Direct domestic water circulation SWH with tickelmann coil assembly. [0103] FIG. 1-B: SWH with an integrated coil in tank and ‘S’ coil in collector. [0104] FIG. 2: Thermosyphon glazed flat-plate SWH collector components [0105] FIG. 3: Schematic diagram of the improved thermosyphon glazed flat-plate SWH [0106] FIG. 4: collector absorber and primary framing of the improved SWH. [0107] FIG. 5: Sun path and day length of the city of Nouaceur in summer and in winter [0108] FIG. 6: Glazing and secondary aluminum framing of the improved thermosyphon glazed flat-plate SWH. [0109] FIG. 7: Components Sub-supports of the improved thermosyphon glazed flat-plate SWH. [0110] FIG. 8: Mirrors positions and angles fixation of the improved thermosyphon glazed flat-plate SWH by season. [0111] FIG. 8-E—Direct and reflective (relatively to mirrors angles) solar radiation, city of Nouaceur on Jun. 25, 2019 at 2:00 p.m. GMT+1 [0112] FIG. 8-F—Direct and reflective (relatively to mirrors angles) solar radiation, city of Nouaceur on Jan. 1, 2019 at 2:00 p.m. GMT+1 [0113] FIG. 9: Azimuth and Elevation, parameters used to locate sun position in relation to the earth at a given place and time of year [0114] FIG. 10: Circulator used to transport hot water to the SWH tank. [0115] FIG. 11: Electrical circuit control ling the improved thermosyphon glazed flat-plate SWH. [0116] FIG. 12: Overview of the improved thermosyphon glazed flat-plate SWH.