Patent Publication Number: US-2003230300-A1

Title: Solar energy collecting device with a thermal conductor, and water heating apparatus using the solar energy collecting device

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
     [0001] This application claims priority of Taiwanese Patent Application No. 091112928, filed on Jun. 13, 2002. 
    
    
     
       BACKGROUND OF THE INVENTION  
       [0002] 1. Field of the Invention  
       [0003] The invention relates to a solar energy collecting device, more particularly to a solar energy collecting device with a thermal conductor.  
       [0004] 2. Description of the Related Art  
       [0005]FIG. 1 illustrates a conventional water heating apparatus  1  that includes a base frame  11 , a water tank  12  mounted on one side of the base frame  11  and having a water inlet  121  and a water outlet  122 , and a plurality of heat-absorbing pipes  13  disposed inclinedly between the water tank  12  and the other side of the base frame  11 . Each heat-absorbing pipe  13  has a connecting end  131  connected to and in fluid communication with the water tank  12 , and a closed end  132  opposite to the connecting end  131  and disposed lower than the connecting end  131 . When the heat-absorbing pipes  13  are irradiated by solar radiation (as indicated by arrows in FIG. 2), due to the reason that cool water has a specific gravity larger than that of hot water, heating circulation is thus possible by virtue of the downwardly flowing cool water and upwardly flowing hot water.  
       [0006] The following are some of the drawbacks of the conventional water heating apparatus  1 :  
       [0007] 1. Each heat-absorbing pipe  13  has a curved heat-absorbing surface that reflects solar radiation, thereby resulting in an inferior heat-absorbing efficiency.  
       [0008] 2. As the cool and hot water flow in opposite directions in the pipes  13 , a great amount of heat loss can occur during thermal conduction.  
       [0009] 3. Since scales are easily generated in the heat-absorbing pipes  13 , in order to maintain better heat-conducting efficiency, periodic cleaning and maintenance are required.  
       SUMMARY OF THE INVENTION  
       [0010] Therefore, the object of the present invention is to provide a solar energy collecting device with a thermal conductor and a water heating apparatus using the solar energy collecting device.  
       [0011] According to one aspect of the present invention, a solar energy collecting device comprises:  
       [0012] a housing confining a receiving space and formed with an opening for access into the receiving space, the housing having a transparent side wall; and  
       [0013] a thermal conductor having a heat-absorbing portion disposed in the receiving space of the housing and a heat-radiating portion extending out of the receiving space via the opening, the thermal conductor including a hollow heat-conducting member that defines a sealed chamber therein and that is formed with a thermal conductor layer in the chamber, the heat-absorbing portion absorbing solar energy when the housing is irradiated by solar radiation and transmitting the solar energy to the heat-radiating portion.  
       [0014] According to another aspect of the present invention, a water heating apparatus comprises:  
       [0015] a water tank having a water inlet and a water outlet; and  
       [0016] a solar energy collecting device including  
       [0017] a housing confining a receiving space and formed with an opening for access into the receiving space, the housing having a transparent side wall, and  
       [0018] a thermal conductor having a heat-absorbing portion disposed in the receiving space of the housing and a heat-radiating portion extending out of the receiving space via the opening and into the water tank, the thermal conductor including a hollow heat-conducting member that defines a sealed chamber therein and that is formed with a thermal conductor layer in the chamber, the heat-absorbing portion absorbing solar energy when the housing is irradiated by solar radiation and transmitting the solar energy to the heat-radiating portion for heating water in the water tank.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0019] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:  
     [0020]FIG. 1 is a perspective view showing a conventional water heating apparatus;  
     [0021]FIG. 2 is a schematic sectional view showing heat-absorbing pipes of the conventional water heating apparatus taken along line II-II in FIG. 1;  
     [0022]FIG. 3 is a perspective view showing the first preferred embodiment of a water heating apparatus according to the present invention;  
     [0023]FIG. 4 is an exploded perspective view showing a solar energy collecting device of the first preferred embodiment;  
     [0024]FIG. 5 is schematic sectional view showing the solar energy collecting device of the first preferred embodiment;  
     [0025]FIG. 6 is a perspective view showing a solar energy collecting device of the second preferred embodiment of a water heating apparatus according to the present invention; and  
     [0026]FIG. 7 is a schematic sectional view showing the solar energy collecting device of the second preferred embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0027] Referring to FIG. 3, the first preferred embodiment of a water heating apparatus  6  according to the present invention is shown to include a water tank  6 , and a solar energy collecting device.  
     [0028] The water tank  6  is mounted on a supporting frame, and has a water inlet  61  and a water outlet  62 .  
     [0029] Referring further to FIGS. 4 and 5, the solar energy collecting device includes a housing  3  and a thermal conductor  4 . The housing  3  has an inner surface  32  that confines a receiving space  33 , and is formed with an opening  31  for access into the receiving space  33 . In this embodiment, the housing  3 , which is rectangular, is formed integrally from a transparent material, such as reinforced glass or heat-resistant transparent plastic. The thermal conductor  4  has a heat-absorbing portion  412  disposed in the receiving space  33  of the housing  3 , as shown in FIG. 5, and a heat-radiating portion  413  extending out of the receiving space  33  via the opening  31  and into the water tank  6 , as shown in FIG. 3. The thermal conductor  4  includes a hollow heat-conducting member  41 , which is a rectangular member, that defines a sealed chamber  411  therein and that is formed with a thermal conductor layer  42  in the chamber  411  (see FIG. 5). It is noted that the thermal conductor layer  42  consists of a superconductor that includes at least one compound selected from the group consisting of sodium peroxide, sodium oxide, beryllium oxide, manganese sesquioxide, aluminum dichromate, calcium dichromate, boron oxide, dichromate radical, and combinations thereof; at least one compound selected from the group consisting of cobaltous oxide, manganese sesquioxide, beryllium oxide, strontium chromate, strontium carbonate, rhodium oxide, cupric oxide, β-titanium, potassium dichromate, boron oxide, calcium dichromate, manganese dichromate, aluminum dichromate, dichromate radical, and combinations thereof; or at least one compound selected from the group consisting of denatured rhodium oxide, potassium dichromate, denatured radium oxide, sodium dichromate, silver dichromate, monocrystalline silicon, beryllium oxide, strontium chromate, boron oxide, sodium peroxide, β-titanium, a metal dichromate, and combinations thereof. The superconductor forms a lining serving as the thermal conductor layer  42  on an inner surface  410  of the heat-conducting member  41  via known techniques (see FIG. 2).  
     [0030] Moreover, the heat-absorbing portion  412  of the thermal conductor  4  has an outer surface  4121  that is further formed with a heat-absorbing film  5  for enhancing the heat-absorbing efficiency of the thermal conductor  4 . It is noted that the heat-absorbing film  5  is preferably formed by magnetically controlled sputtering.  
     [0031] The heat-absorbing portion  412  of the thermal conductor  4  absorbs solar energy when the housing  3  is irradiated by solar radiation, and then transmits the solar energy to the heat-radiating portion  413  for heating water in the water tank  6 .  
     [0032]FIGS. 6 and 7 illustrate a solar energy collecting device of the second preferred embodiment of a water heating apparatus according to the present invention, which is a modification of the first preferred embodiment. Unlike the previous embodiment, the housing  3 ′ includes a base body  7 , and a transparent cover  8  mounted on the base body  7 . The base body  7  and the transparent cover  8  confine the receiving space  73 . The transparent cover  8  is made of reinforced glass or heat-resistant transparent plastic.  
     [0033] The following are some of the advantages attributed to the water heating apparatus of the present invention:  
     [0034] 1. The whole area of the outer surface  4121  of the heat-absorbing portion  412  of the hollow heat-conducting member  41  can serve as a heat-absorbing area, thereby resulting in a superior heat-absorbing efficiency.  
     [0035] 2. Due to the presence of the thermal conductor  4 , the solar energy absorbed at the heat-absorbing portion  412  can be transmitted to the heat-radiating portion  413  with high efficiency so as to reduce the heat loss commonly encountered in the aforesaid prior art.  
     [0036] 3. The solar energy collecting device of the present invention utilizes the thermal conductor  4  as a heat-conducting medium rather than water such that the problem of scaling in the aforesaid prior art does not occur.  
     [0037] While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.