Patent Publication Number: US-2013239949-A1

Title: Solar water heater

Description:
FIELD OF TECHNOLOGY 
     This disclosure relates to a solar water heater. 
     BACKGROUND 
     Ordinary solar water heaters typically use glass thermo-collecting tubes to collect heat, and typically use bucker-shape water tank to store hot water. Water heaters in this type may produce high water with high temperature, and have high heat efficiency; however water heaters in this type may also have problems including bulky in size, complicate in design, and costly in manufacturing. High cost may limit the water heaters being widely used, especially in tropical or semitropical zones having plenty of hours of daylight and higher average temperature. In such places slightly lower heat efficiency is acceptable, and people there may care more about lowering manufacturing costs in order to lower sale price and to promote the use of solar water heaters. 
     SUMMARY 
     The purposes intended to be achieved by the embodiments disclosed herein are to provide a solar water heater which is simpler in design, more compact in space usage, and lower in manufacturing cost. 
     In order to achieve the purposes above, some embodiments disclosed herein may utilize the following technical schemes: 
     Some embodiments disclosed are related to a solar water heater, which may include an outer housing and a heat absorbing water tank fixed onto the interior surface of the outer housing. The heat absorbing water tank may have a water entrance and a water exit, and may have the following features: there may be a heat insulating layer filled underneath the heat absorbing water tank, between the heat absorbing water tank and the outer housing, and there may be a transparent heat insulating board placed on top of the heat absorbing water tank. 
     The above disclosed heating absorbing water tank may include a plurality of transverse tubules placed in parallel with each other and a plurality of longitudinal tubules placed in parallel with each other. The plurality of transverse tubules and the plurality of longitudinal tubules may be placed coplanarly and be inter-connected, and there may be ribs connecting outerwalls of adjacent transverse tubules or outerwalls of adjacent longitudinal tubules. 
     The above disclosed heat absorbing water tank may also be a rectangular heat absorbing water tank. The top surface of the rectangular heat absorbing water tank may have a plurality of rectangular pyramid shape convexes, and the bottom surface of the rectangular heat absorbing water tank may have a plurality of conical concaves, and the apexes of the conical concaves may reach and become part of the top surface of the rectangular heat absorbing water tank. 
     The above disclosed transverse tubules and longitudinal tubules may be circular tubules having circular shape cross sections, and at least either the transverse tubules or the longitudinal tubules may have a wave axis line, and the transverse tubules and the longitudinal tubules may intersect at a wave crest or a wave trough of the wave axis line. 
     The above disclosed transverse tubules and longitudinal tubules may be circular tubules having circular shape cross sections, and the transverse tubules and the longitudinal tubules may be both straight tubules. 
     A water storing water tank may be placed on top of the heat absorbing water tank. The water exit of the heat absorbing water tank may be connected to the water storing water tank, and the water entrance of the heat absorbing water tank may be connected to the water storing water tank via a return water pipe. A valve may be placed at the water entrance of the heat absorbing water tank. 
     A water storing water tank and an electric heating chamber may be embedded in the heat insulating layer filled underneath the heat absorbing water tank. The two ends of the water storing water tank may be connected to the water entrance and water exit of the hear absorbing water tank via connecting tubes, and the electric heating chamber may be placed in series between the water storing water tank and the connecting tubes connecting to the water entrance. The electric heating chamber may have an electric heater inside of it. 
     The above disclosed heat absorbing water tank may have a caecal tube. The caecal tube may have a closed top, and the bottom of the caecal tube is connected to a core space within the heat absorbing water tank via a connector. 
     The above disclosed water storing water tank may have a caecal tube. The caecal tube may have a closed top, and the bottom of the caecal tube is connected to a core space within the water storing water tank via a connector. 
     By using the above disclosed technical schemes, the heat absorbing water tank may be manufactured using plastic materials. The heat absorbing water tank is likely to withstand a water pressure caused by tap water, is not likely to accumulate scale incrustation, and is likely to be corrosion resistant. The heat absorbing water tank is likely to be more compact, easier in design, lower in manufacturing cost, and more convenient in design and installation. The heat absorbing water tank is thus likely to be more widely used in an area with higher average temperature. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following is a brief explanation of embodiments herein using drawings: 
         FIG. 1  is a longitudinal cross sectional view of an embodiment. 
         FIG. 2  is a transverse cross sectional view of the embodiment of  FIG. 1 . 
         FIG. 3  illustrates schematic view of a heat absorbing water tank of the embodiment of  FIG. 1 . 
         FIG. 4  illustrates a close-up view of part A of  FIG. 3 . 
         FIG. 5  is a cross sectional view of the embodiment of  FIG. 1 , taken from the line B-B in the direction generally indicated. 
         FIG. 6  illustrates a close-up view of part E of  FIG. 5 . 
         FIG. 7  is a longitudinal cross sectional view of another embodiment. 
         FIG. 8  is a transverse cross sectional view of the embodiment of  FIG. 7 . 
         FIG. 9  is a longitudinal cross sectional view of a third embodiment. 
         FIG. 10  is a transverse cross sectional view of the embodiment of  FIG. 9 . 
         FIG. 11  illustrates a schematic view of a fourth embodiment. 
         FIG. 12  illustrates a schematic view of a fifth embodiment. 
         FIG. 13  illustrates a schematic view of a sixth embodiment. 
         FIG. 14  illustrates a schematic view of a seventh embodiment. 
         FIG. 15  illustrates a schematic view of an eighth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in the drawings, the embodiments disclosed herein relate to a solar water heater including an outer housing  1  and a heat absorbing water tank  2  fixed onto the interior surface of the outer housing  1 . The heat absorbing water tank  2  may have a water entrance  3  and a water exit  4 . A heat insulating layer  5  may be filled underneath the heat absorbing water tank  2  between the heat absorbing water tank  2  and the outer housing  1 , and a transparent heat insulating board  6  may be placed on top of the heat absorbing water tank  2 . To reduce cost, the heat absorbing water tank  2  and the outer housing  1  may be built using plastic materials; however to achieve heating efficiency, the heat absorbing water tank  2  may be built using plastic materials having better heat absorbing capacity. The transparent heat insulating board  6  may be built using a glass board good in light transmittance and heat insulation, or using an intercalated, cannulate glass board. The embodiment thus allows the heat absorbing water tank  2  to be exposed to sunlight, while prevents the heat absorbing water tank  2  from heat dissipation through air convection. 
     The above disclosed heat absorbing water tank  2  may have two other embodiments, as shown in  FIG. 3  to  FIG. 6 . The above disclosed heat absorbing water tank may include a plurality of transverse tubules placed in parallel with each other and a plurality of longitudinal tubules placed in parallel with each other. The plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  may be placed coplanarly and be inter-connected, and there may be ribs  24  connecting outer walls of adjacent transverse tubules or outer walls of adjacent longitudinal tubules. Thus, the plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  may be interconnected forming a web structure, which may be exposed to sunlight to a maximum extent, thus may improve the efficiency in utilizing sunlight and may at the same time have the ability to withstand higher pressure, and may be used in a pressure-bearing solar water heater. Inside the heat absorbing water tank  2 , the web structure formed by the plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  may further form a mesh-like water system, which may heat water more quickly and may facilitate heat exchange. 
     The plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  disclosed above may be circular tubules having circular shape cross sections, and at least either the plurality of transverse tubules  21  or the plurality of longitudinal tubules  22  may have a wave axis line, and the plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  may intersect at a wave crest or a wave trough of the wave axis line. In these embodiments the length of the plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  may be maximized to a greater extent within a limited space, which may increase the surface for heat exchange and may at the same time enlarge the volume of the heat absorbing water tank  2 . The plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  may both be straight tubules. A wave tubule is a tubule having wave axis line, and when either of the plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  are wave tubules, the plurality of transverse tubules  21  and the plurality of longitudinal tubules  22  may still intersect at a wave crest or a wave trough of the wave axis line of the wave tubules. 
     A second embodiment is shown in  FIG. 7  and  FIG. 8 . In order to increase the volume of the water tank, a plurality of heat absorbing water tanks  2  may be used together connected in series or in parallel. 
     A third embodiment is shown in  FIG. 9  and  FIG. 10 . The above disclosed heat absorbing water tank  2  may be a rectangular water tank. A top surface of the rectangular water tank may have a plurality of rectangular pyramid shape convexes  25 , which may increase the surface area exposed to sunlight radiation. A bottom surface of the rectangular water tank may have a plurality of conical concaves  23 , and the apexes of the conical concaves  23  may be welded to and become part of the top surface of the rectangular water tank. The conical concaves may serve the following two functions: first, they may increase the strength of the structure, allowing more connecting points between the top surface and the bottom surface of the rectangular water tank and reinforcing the structure; second bolt orifices may be placed within the conical concaves  23  for securing connections, and because the peak of a conical concave may have a one-layer structure, placing a bolt orifice within the conical concave may not introduce concerns about anti-leaking and water-proofing, which may increase reliability and reduce manufacturing costs. 
     A fourth embodiment is shown in  FIG. 11 . The above disclosed heat absorbing water tank  2  may be tilted and installed on a bracket  11 , and a water storing water tank  7  may be placed on top of the heat absorbing water tank  2 . The water exit  4  of the heat absorbing water tank  2  may be connected to the water storing water tank  7 , and the water entrance  3  of the heat absorbing water tank  2  may be connected to the water storing water tank  7  via a return water pipe  8 . Two valves  9  and  10  may be placed at the water entrance  3  of the heat absorbing water tank  2 . When the valves  9  and  10  are open, water inside the heat absorbing water tank  2  may be heated and may elevate up into the water storing water tank  7 , and water inside the water storing water tank  7  having a lower temperature may return into the heat absorbing water tank  2  through the return water pipe  8  and the water entrance  3 . This cycle may allow the heating up of water inside the water storing water tank  7  and the heat absorbing water tank  2 . When a plurality of heat absorbing water tanks  2  are connected in series, closing the valve(s) of one or several water entrance(s) may screen their respective heat absorbing water tank(s) from cycling with the water storing water tank  7 , allowing more flexibility to the system. The valves disclosed herein may be manually controlled valves, or may be electro-magnetic valves. 
     It is to be understood that in this embodiment, the heat absorbing water tank  2  may also be a rectangular heat absorbing water tank  2  disclosed above. 
     A fifth embodiment is shown in  FIG. 12 . A water storing water tank  7  may be embedded in the heat insulating layer  5  filled underneath the heat absorbing water tank  2 . The two ends of the water storing water tank  7  may be connected to the water entrance  3  and water exit  4  via connecting tubes. The water storing water tank  7  may be in rectangular flat plate construction, allowing more water storage, and at the same time embedding the water storing water tank  7  into the heat insulating layer  5  may simplify the structure and help heat preservation. 
     A sixth embodiment is shown in  FIG. 13 . A water storing water tank  7  and an electric heating chamber  30  may be embedded in the heat insulating layer  5  filled underneath the heat absorbing water tank  2 . The two ends of the water storing water tank  7  may be connected to the water entrance  3  and water exit  4  via connecting tubes. The electric heating chamber  30  may be placed in series between the water storing water tank  7  and the connecting tubes connecting to the water entrance  3 . The electric heating chamber  30  may have an electric heater  31  inside of it. The electric heater may be used to provide additional heat when sunlight alone is insufficient for heating purposes. 
     A seventh embodiment is shown in  FIG. 14 . When the heat absorbing water tank  2  is the rectangular heat absorbing water tank  2  disclosed above, the water storing water tank  7  may not be used. An electric heater  31  may be placed directly at the water entrances of the rectangular heat absorbing water tank to provide additional heat. 
     An eighth embodiment is shown in  FIG. 15 . The above disclosed heat absorbing water tank  2  may have a caecal tube  51 . The caecal tube  51  may have a closed top, and the bottom of caecal tube  51  is connected to a core space within the heat absorbing water tank  2  via a connector  52 . The caecal tube  51  may be constructed using pressure resistant seamless steel pipe, and it may also be constructed using materials having better air tightness such as stainless steel or plastics. The caecal tube  51  may have a rounded section, and it may also have a polygonal section. Because bottom of the caecal tube  51  is connected to the core space of the heat absorbing water tank  2 , the caecal tube  51  may always contain a certain amount of air inside of it. When an air pressure of tap water suddenly increases, the air contained in the caecal tube  51  may be pressed and may reduce in volume, providing a buffer and effectively reducing the pressure from a water hammer effect produced when a valve is opened or closed. 
     In another embodiment, when using the water storing water tank  7  disclosed above, the water storing water tank  7  may have a caecal tube  51 . The caecal tube  51  may have a closed top, and the bottom of the caecal tube  51  is connected to a core space within the water storing water tank  7  via a connector  52 . The caecal tube  51  herein serves the same functions to provide a buffer and to reduce the pressure from a water hammer effect.