Patent Publication Number: US-2009229540-A1

Title: Water heater

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a heating device, and more particularly to a water heater. 
     2. Description of the Related Art 
     Typically, conventional water heaters include gas water heaters and electric water heaters. The gas water heater has a continuous S pipe therein and a gas burner heating the pipe directly. The electric water heater has two types. The first type has an electric heater to heat water directly. The second type has electromagnetic heating means, which generates an eddy current to induce a metal block, and then water flows through the metal block to be heated. Typically, the gas water heater has a poorer efficiency than the electric water heater, and it has to consider the air ventilation issue for the place mounting the gas water heater to avoid accident. The other problem of the gas water heater is that it usually has a long distance between the water heater and the hydrant that user has to wait for the cold water in the pipe running out before the water comes out, and the temperature will loss in the long pipe also. Another issue of the gas water heater is temperature control. It is caused by the long pipe also to have the reaction time of temperature change too slow that user usually over adjusts to make the water temperature too hot or too cold when the water temperature had been changed to the designed temperature. Some small electric water heaters have no water tank therein that such water heater may be mounted in the house. The advantage of it is fast reaction in temperature adjustment, and the drawback of it is that it can not supply sufficient hot water. There are large electric water heaters in the present market, which may supply sufficient hot water. However, the mounting place is limited, and it still has the problem of too long distance between the water heater and hydrant. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a water heater, which has a superior heat efficiency to save power and supply enough hot water. 
     According to the objective of the present invention, a water heat includes a case having an airtight chamber therein, a water pipe received in the chamber of the case with a first connection end and a second connection end extended out of the case respectively, a thermal medium, which is liquid in a room temperature, received in the chamber of the case, and a heating device for heating the thermal medium directly or indirectly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a first preferred embodiment of the present invention; 
         FIG. 2  is a sectional view along the 2-2 line of  FIG. 1 ; 
         FIG. 3  is a sectional view of the first preferred embodiment of the present invention, showing the operation of the water heater; 
         FIG. 4  is a sectional view of a second preferred embodiment of the present invention; 
         FIG. 5  is a sectional view of a third preferred embodiment of the present invention; 
         FIG. 6  is a sectional view of a fourth preferred embodiment of the present invention; 
         FIG. 7  is a sectional view of a fifth preferred embodiment of the present invention; and 
         FIG. 8  is a sectional view of a sixth preferred embodiment of the present invention 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIG. 1  and  FIG. 2 , a water heater  10  of the first preferred embodiment of the present invention includes: 
     A case  20  has an airtight chamber  30  therein, with a pressure lower than one atmospheric pressure. The chamber  30  is preferred vacuumed. The required pressure in the chamber  30  is less than 10 −1  Torr, and more preferable is less than 10 −2  Torr, and further more preferable is less than 10 −3  Torr. 
     A water pipe  40  is a continuous S-shaped pipe mounted in the case  20 , which has a first connection end  41  and a second connection end  42  extended out of the case  20  respectively at opposite sides of the case  20 , and the second connection is at a higher position and the first connection end is at a lower position, as shown in  FIG. 2 . In practice, the first and second connection ends  41 ,  42  of the water pipe  40  are to connectors connected to external pipes to keep the airtight condition of the chamber  30 . 
     A thermal medium  50 , which is a liquid in room temperature with a lower vaporized temperature, is received in the chamber  20  of the case  10 . A need of the thermal medium  50  is not much. Typically, sufficient thermal medium  50  only takes 1.5% to 20% of a volume of the chamber  20 , preferable is 2% to 15%, and more preferable is 10%. The consideration of the quantity of the thermal medium  50  is cost and heat transfer efficiency. Any quantity of the thermal medium  50  in the chamber  20  should be still in the scope of the present invention. The thermal medium may be a material with a high volatility, such as ether, alcohol, benzene or a mixture of above, or other suitable materials. 
     A heating device  60 , which is an electric heater, is mounted on a bottom of the case  10 . 
     As shown in  FIG. 3 , a cold water pipe  11  is connected to the first connecting end  41  of the water pipe  40 , and a hot water pipe  12  is connected to the second connecting end  42  of the water pipe  40 . A power line (not shown) is connected to the heating device  60 . The heating device  60  may be provided with a controller (not shown) for power control, a temperature sensor (not shown) for temperature control, and a flow sensor (not shown) for turn-on or turn-off water. Aforesaid control devices are common in the conventional water heater, so we do not describe the detail here. When the heating device  60  is energized to heat the thermal medium  50  in the case  20 , and then the thermal medium  50  will be vaporized quickly and the vapor of the thermal medium  50  will be full in the chamber  30  to heat the water in the water pipe  40 . it is obvious that the heating area of the water pipe  40  is maximized to the entire surface of the water pipe  40  that would provide the maximum heat efficiency. The vacuum condition is related to vaporization of the thermal medium  50 . The lower pressure in the chamber  30  will get a faster evaporation the thermal medium  50  and a higher heat efficiency. The present invention provides the vaporized thermal medium to be a medium for heat transfer to water, so that the vaporized thermal medium will reach to the whole chamber for heat transfer. That is why the present invention has a higher heat efficiency to heat water quickly. After heat transfer, the liquidized thermal medium  50  will flow back to a bottom of the chamber  30  along an interior wall of the case  20 , and be reheated by the heating device  60  for vaporization again that the water in the pipe may be heated to a desired temperature quickly and flow out the hot water pipe  12  through the second connecting end  42 . 
       FIG. 4  shows a water heater of the second preferred embodiment of the present invention (all of the elements in the following embodiments have the same reference numerals as the corresponding elements in the first preferred embodiment), which is similar to the first preferred embodiment except that a heating device  60 ′ is mounted on a bottom of the chamber  30 , in other words, on a bottom of an interior side of the case  20 . The heating efficiency of the heating device  60 ′ will be better. 
       FIG. 5  shows a water heater of the third preferred embodiment. Basically, it is as same as the second preferred except that the water heater of the third preferred embodiment further includes an outer case  70  to enclose the case  20  therein. A space between the outer case  70  and the case  20  is vacuumed to form a vacuum thermal isolation layer  80 . 
       FIG. 6  shows a water heater of the fourth preferred embodiment of the present invention, which is similar to the third preferred embodiment except that the space between the outer case  70  and the case  20  is not vacuumed but is inserted with a thermal isolation material to form a thermal isolation layer  90 . 
       FIG. 7  shows a water heater of the fifth preferred embodiment of the present invention, which the heating device is a gas burner  100  to replace the electric heater, and an out case  110  is provided to enclose the case  20  therein for wind shield and air guiding. 
     The present invention provides the thermal medium to be the heat transfer medium that the heat generated from the heating device is transferred to the entire space in the case. The water heater of the present invention can heat a greater quantity of water very fast. While the water heater of the present invention is equipped with electric heating device, it can be mounted in the shower room or kitchen directly. It is very easy to mount and operate the water heater of the present invention. Some embodiments provide a thermal isolation device to have all the power in heating water. The power loss is minimized 
       FIG. 8  is a water heater of the sixth preferred embodiment of the present invention, which is equipped with the gas heating device  100  as same as the fifth preferred embodiment. The water heater of the sixth preferred embodiment has the case  20  provided with a tunnel  25  from a bottom to a top thereof. The tunnel  25  is a ventilation passageway for burning gas. A spiral water pipe  40 ′ surrounds the tunnel  25 .