IL165373A - Energy efficient water heater and method of use thereof - Google Patents

Description

in v o^t? rwv n iwi O DPH o own 111 AN ENERGY EFFICIENT WATER HEATER AND A METHOD OF USE THEREOF YAACOV KOLCHEH (O/R: 1857) AN ENERGY EFFICIENT WATER HEATER FIELD OF THE INVENTION The present invention relates to water heaters containing an internal sleeve, for supplying hot water, especially suited for supplying hot water to private dwellings.

BACKGROUND OF THE INVENTION Hot water heaters are often present in apartment buildings or private houses, with each heater supplying a single apartment with hot water. The heater consists of a tank containing a reservoir of water, which may be heated using electrical heating coils, or using solar energy. In order to supply a steady source of hot water, many hot water heaters contain an inner sleeve, surrounding the electrical heating element and delimiting a small quantity of water, and the water within this sleeve is heated more quickly than the remainder of the water in the reservoir. Hot water can be discharged from the sleeve for rapid use, and the user need not wait for the remainder of the water within the reservoir to heat up. When a large quantity of hot water is needed, the user must nevertheless wait for the remainder of the reservoir to heat.

Optionally, the contents of the tank can be in fluid communication with solar panels, so that the electrical heating element need not be used when solar energy is available. In such case, the sleeve is of no importance, as the hot water returning from the solar panels does not enter the sleeve directly. Rather, the hot water enters from an additional inlet present on the main body of the tank, where it mixes with the entire contents of the tank. When solar energy is used, the contents of the sleeve are at a temperature similar to that in the remainder of the tank.

Prior art hot water heaters are not adequately efficient in supplying hot water having a high enough temperature, using a minimal amount of electricity: A prior art electrical water heater containing a prior art sleeve is shown in Figure 1. A cylindrical tank 1 contains an inlet 2 for entiy of cold water, with an electrically operated heating element 3 and a thermostat 4 surrounded by a sleeve structure 5. When the heating element 3 is activated, water 6 within the sleeve 5 is heated, and then tends to rise to exit the sleeve 5 through an opening 7 at the top of the sleeve 5. This hot water 6 tends to remain at the upper areas of the tank 1, due to its low density. However, there is a certain degree of cooling of this water, since after its exit from the sleeve it mixes with water in the remainder of the tank, which has not been heated. Only after this mixing has occurred, is the water discharged through a hot water discharge pipe 8, for use in a residence. This drawback exists in typical prior art water heaters.

In addition, in a typical prior art water heater, such as that shown in Figure 1, the hot water discharge pipe 8 is surrounded by water in Region A which tends to be cooler than that found in the upper regions of the tank. Typically, the discharge pipe 8 extends vertically through the majority of the tank 1 length, before being released through the hot water outlet 9 at the bottom of the tank 1. Therefore, when hot water is passed through the hot water discharge pipe 8 for release and subsequent use in the residence, it tends to cool as it flows downwards through Region A within the discharge pipe 8. This inefficiency raises the need for a more economical water heater. The need is especially great in places where the cost of electricity is high.

U.S. Patent No. 6,321,036 to Huang attempts to address these drawbacks. However, the heater disclosed by Huang contains inner partition walls that are inseparable from the tank body, thus the tank must be manufactured specifically for this design. This adds to the cost of the water tank, and does not allow the wide variety of water tanks presently on the market to be retrofitted with the heating elements and partitions disclosed in U.S. 6,321,036. In addition, the water heater disclosed by Huang is most suited for supplying water for a central heating system, since the preferred embodiments describe use of three heating elements, indicating a large volume of water. Operation of more than one heating element would overwhelm the electrical capacity typically present for a single residence in many countries, and would require special rewiring of the electrical system.

The need exists for an economical and electrically efficient water heater, which does not require exceptional manufacture of a specialized tank, rather whose design allows retrofitting of prior art tanks with the innovative elements disclosed below.

' SUMMARY OF THE INVENTION Accordingly, it is a principal object of the present invention to overcome the disadvantages of the prior art water heater designs.

It is an object of the present invention to provide a water tank containing a removeably insertable sleeve, having a design which grants higher energy efficiency and therefore consumes less electricity than prior art water tanks, while supplying a given quantity of hot water for use.

The present invention thus provides an energy efficient water heater comprising: a. a thermally insulated storage tank; b. water supply means including a cold water inlet on said tank and a hot water outlet, and including a plurality of valves; and c. a removeably insertable sleeve assembly within said tank, comprising a sleeve wall capable of delimiting a quantity of water within said assembly, and said sleeve wall includes at least one opening for fluid communication with the contents of the storage tank, and said sleeve wall surrounds and contains within: i) an electrical heating element; ii) a temperature sensor; iii) a hot water discharge pipe connected to the hot water outlet on said tank; wherein the majority of the discharge pipe is present within the sleeve such that water passing through the hot water discharge pipe does not cool.

According to the most preferred embodiment, the hot water discharge pipe is present in its entirety within the sleeve assembly.

In a preferred embodiment, the sleeve assembly further comprises a horizontal partition dividing the sleeve into an upper chamber for containing the hottest water, and a lower chamber, with an aperture in said partition wall, allowing fluid communication between said two chambers. In such case, in certain embodiments the inlet of the hot water discharge pipe is present in said upper sleeve chamber, allowing rapid discharge of hot water from the upper chamber through the hot water outlet.

In another embodiment, the partitioned sleeve further comprises an internal channeling pipe fitted in the aperture of the partition wall, for channeling hot water from the lower chamber into the upper chamber. In such case, according to one embodiment, the outlet of the channeling pipe is lower than the inlet of the hot water discharge pipe.

Further, in some embodiments of the partitioned sleeve, an opening is present in the upper chamber, allowing exit of hot water from the upper chamber in the sleeve assembly and entry into the tank.

Moreover, in a preferred embodiment of the partitioned sleeve the height of the upper chamber is 30 cm.

Additionally, according to certain embodiments, the water heater is connected to absorber panels defining a thermosiphon recirculation pathway within the water heater, allowing utilization of solar energy for heating the water.

Further, in some embodiments, at least one cavity is defined in the sleeve wall, adjacent to the heating element, for allowing release of mineral buildup from the heating element.

Optionally, the water heater further comprises a temperature sensor for activating the electrical heating element automatically when the temperature in the tank is low.

In some embodiments, the water heater further comprises a water-level sensor for measuring the height of the water in the tank and capable of controllmg the water level by activating the cold water inlet valve.

The sleeve assembly of the invention can be marketed as a single unit, for insertion into a water heater. This assembly can be installed either into a prior, art water heater, to upgrade its energy efficiency, or to replace a similar assembly when the need exists. The sleeve assembly is comprised of a sleeve wall including at least one opening for fluid communication with the contents of a water storage tank, and the sleeve wall contains within an electrical heating element, a temperature sensor, and a hot water discharge pipe. The majority of the discharge pipe is present within the sleeve, so that water passing through the hot water discharge pipe does not cool.

These and other advantages of the present invention will become more apparent from the detailed description of the invention that follows.

BRIEF DESCRIPTION OF THE INVENTION For a better understanding of the present invention with regard to the embodiments thereof, reference is made to the accompanying drawings, in which like numerals designate corresponding elements or sections throughout, and in which: Figure 1 is a cross-sectional view of a prior art electrical water heater containing a sleeve; Figure 2 is a cross-sectional view of a water heater containing a sleeve according to the present invention; and Figure 3 is a side-view illustrating insertion of the sleeve containing its internal structures for retrofitting a prior art water heater or for easy replacement of the sleeve and its internal elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It is appreciated that the detailed description that follows is intended only to illustrate certain preferred embodiments of the present invention. It is in no way intended to limit the scope of the invention, as set out in the claims.

Referring to Figure 2, the internal components of the water heater are shown. A standard cylindrical storage tank 1 is covered by a layer of insulating material 10 to prevent heat loss through the tank walls. The insulating material 10 is trapped between the internal tank wall 1 1 and a durable stainless steel outer wall 12.

Preferably the external and internal walls of the storage tank are formed of stainless steel, having a thickness of 0.5 mm, and the insulating material is a foamed layer having a thickness of 5-7 cm.

A cold water inlet 2 allows a supply of cold water to enter the storage tank 1 through a valve 27 contained within this inlet.

The novel sleeve assembly 13 of the invention contains an electrical heating element 14, a temperature sensor 15, and a hot water discharge pipe 16, all surrounded by and contained within a cylindrical sleeve wall 26.

According to the most preferred embodiment, a horizontal partition 17 divides the sleeve into an upper chamber 18 for containing the hottest water, and a lower chamber 19. An aperture exists in the partition 17, allowing fluid communication between the two chambers. In the embodiment shown in Figure 2, an internal channeling pipe 20 is fitted in said aperture, for channeling hot water from the lower chamber 19 into the upper chamber 18.

In use, the consumer activates the electrical heating element 14 using a switch installed within his home. The water contained within the sleeve wall 26 is the first to heat, being in closest proximity to the heating element 14. The hot water rises through the internal channeling pipe 20 to the upper chamber 18 of the sleeve assembly 13, due to the physical properties of hot water compared to cold water. When the user requires hot water, it is drawn through the hot water discharge pipe 16 from the upper chamber 18 which contain the hottest water, and after passing within the hot water discharge pipe 16 it exits through a valve 25 at the base of the tank 1.

Thus, the time necessary before hot water is obtainable is considerably reduced, since the hottest water tends to remain within the upper chamber 18, which surrounds and encloses the hottest water. Approximately 10 minutes of operation of the heating element 14 usually suffices before hot water is obtainable.

During prolonged activation of the heating element 14, hot water exits from an opening 23 in the upper chamber 18, to mix with the general reservoir of water contained within the tank 1, outside of the sleeve assembly. The hotter water will tend to remain in the upper areas of the tank 1, and can be released to the consumer through the hot water discharge pipe 16.

A key element of the present invention is that the hot water discharge pipe 16 is present within the sleeve assembly 13, thus when water flows through it for release to the consumer, it does not cool as it is surrounded by hot water. Recall that in prior art water heaters with sleeves, the hot water discharge pipe is present in the general reservoir of the tank, and is surrounded by cooler water which lowers the temperature of the water being discharged. In contrast, in the most preferred embodiment of the present invention, the hot water discharge pipe 16 is present in its entirety within the sleeve assembly 13. Thus, though it extends downwards from the upper chamber 18 and the water within it must pass the majority of the height of the tank 1 before being released through the base of the tank 1, there is no cooling of the water being discharged, by surrounding waters.

Optionally, the tank 1 can be connected to absorber panels defining a thermosiphon recirculation pathway, allowing use of solar energy when it is available, for heating the water. In such case, an outlet 21 allows exit of water from the reservoir to the solar panels (not shown), and an inlet 22 allows return of the hot water to the reservoir in the tank 1. Preferably, the outlet of the channeling pipe 20 at the upper end, is lower than the inlet of the hot water discharge pipe 16, so that when hot water returns from the solar absorber panels, it enters through opening 23 in the upper chamber 18 to flow primarily into the inlet of the hot water discharge pipe 16.

Preferably, two cavities 24 are defined in the sleeve wall 26 adjacent to the electrical heating element 14, allowing solid mineral crusts which tend to build up on the heating element 14, to break and be released from these cavities 24 due to flow through of cold water from the cold water inlet 2. The cold water flows into the sleeve through the cavities 24, to replenish the water within the sleeve. A preferred dimension of the cavities 24 is 5-7 cm for the radius of each circular cavity 24.

Preferably, the height of the upper chamber is 30 cm.

Optionally, a temperature sensor may be included, to activate the electrical heating element automatically and repetitively, when the temperature in the tank is low, so that the temperature in the tank is constantly kept warm. Alternatively, the consumer may activate the electrical heating element by means of a switch installed within his home.

Optionally, a water-level sensor (not shown) may be present to measure the height of the water in the tank and control the water level by interacting with the cold water inlet valve, by enabling new cold water to enter the tank when the sensor indicates that the water level is low.

Referring to Figure 3, the sleeve assembly 13 and its internal structures (heating element 14, temperature sensor 15, hot water discharge pipe 16 and respective upper and lower chambers 18, 19) can be easily installed or removed from a standard tank 1. This allows retrofitting a prior art water heater tank with the sleeve assembly of the present invention, for upgrading the electrical efficiency of a prior art heater. Additionally, the lifetime of an electrical heating element tends to be approximately three years, while the lifetime of a standard tank tends to be approximately ten years. Thus, the sleeve assembly according to the present invention and its internal structures are easily removable from the water tank and replaceable when the heating element is in need of replacement.

The present invention thus provides an easily insertable and removeable sleeve assembly for use inside a water heater, having electrical efficiency and economy in comparison to prior art water heaters with sleeve inserts.

Having described the invention with regard to certain specific embodiments thereof, it is to be understood that the description is not meant as a limitation, since further modifications may now suggest themselves to those skilled in the art. It is intended to cover such modifications that fall within the scope of the appended claims.

ABSTRACT The present invention provides an energy efficient electrical water heater having a sleeve assembly within. In the removeably msertable sleeve assembly, the majority of the discharge pipe is present within the sleeve such that water passing through the hot water discharge pipe does not cool, and the inlet of the discharge pipe is located within the upper portion of said sleeve. The sleeve assembly may be used to retrofit prior art water heaters.

Claims (24)

1. An energy efficient water heater comprising: a. a thermally insulated storage tank; b. water supply means including a cold water inlet on said tank and a hot water outlet, and including a plurality of valves; and c. a removeably insertable sleeve assembly within said tank, comprising a sleeve wall capable of delimiting a quantity of water within said assembly, and said sleeve wall includes at least one opening for fluid communication with the contents of the storage tank, and said sleeve wall surrounds and contains within: i) an electrical heating element; ii) a temperature sensor; iii) a hot water discharge pipe connected to the hot water outlet on said tank; wherein the majority of the discharge pipe is present within the sleeve such that water passing through the hot water discharge pipe does not cool, and wherein the inlet of said discharge pipe is located within the upper portion of said sleeve.

2. The water heater of claim 1 wherein said hot water discharge pipe is present in its entirety within the sleeve assembly.

3. The water heater of claim 1, wherein said sleeve assembly comprises a horizontal partition dividing the sleeve into an upper chamber for containing the hottest water, and a lower chamber, with an aperture in said partition wall, allowing fluid communication between said two chambers.

4. The water heater of claim 3, wherein the inlet of the hot water discharge pipe is present in said upper sleeve chamber, allowing rapid discharge of hot water from the upper chamber through the hot water outlet. 8

5. The water heater of claim 3, further comprising an internal channeling pipe fitted in said aperture, for channeling hot water from the lower chamber into the upper chamber.

6. The water heater of claim 5, wherein the outlet of said channeling pipe is lower than the inlet of the hot water discharge pipe.

7. The water heater of claim 3, wherein an opening is present in the upper chamber, allowing exit of hot water from the upper chamber in the sleeve assembly and entry into the tank.

8. The water heater of claim 3, wherein the height of the upper chamber is 30 cm.

9. The water heater of claim 1, wherein said water heater is connected to absorber panels defining a thermosiphon recirculation pathway within said water heater, allowing utilization of solar energy for heating the water.

10. The water heater of claim 1, wherein at least one cavity is defined in the sleeve wall, adjacent to the heating element, for allowing release of mineral buildup from the heating element.

11. The water heater of claim 1, further comprising a temperature sensor for activating the electrical heating element automatically when the temperature in the tank is low.

12. The water heater of claim 1, further comprising a water-level sensor for measuring the height of the water in the tank and capable of controlling the water level by activating the cold water inlet valve.

13. A removeably insertable sleeve assembly for use within a water heater tank, comprising a sleeve wall capable of delimiting a quantity of water within, and said sleeve wall includes at least one opening for fluid communication with the contents of a water storage tank, and said sleeve wall surrounds and contains within: a. an electrical heating element; 9 b. a temperature sensor; c. a hot water discharge pipe for communication with the hot water outlet on said tank; wherein in the sleeve assembly the majority of the discharge pipe is present within the sleeve such that water passing through the hot water discharge pipe does not cool, and wherein the inlet of said discharge pipe is located within the upper portion of said sleeve.

14. The sleeve assembly of claim 13 wherein said hot water discharge pipe is present in its entirety within the sleeve assembly.

15. The sleeve assembly of claim 13, wherein said sleeve assembly comprises a horizontal partition dividing the sleeve into an upper chamber for containing the hottest water, and a lower chamber, with an aperture in said partition wall, allowing fluid communication between said two chambers.

16. The sleeve assembly of claim 15, wherein the inlet of the hot water discharge pipe is present in said upper sleeve chamber, allowing rapid discharge of hot water from the upper chamber.

17. The sleeve assembly of claim 15, further comprising an internal channeling pipe fitted in said aperture, for channeling hot water from the lower chamber into the upper chamber.

18. The sleeve assembly of claim 17, wherein the outlet of said channeling pipe is lower than the inlet of the hot water discharge pipe.

19. The sleeve assembly of claim 15, wherein an opening is present in the upper chamber, allowing exit of hot water from the upper chamber in the sleeve assembly and entry into a water heater tank.

20. The sleeve assembly of claim 15, wherein the height of the upper chamber is 30 cm. 10

21. The sleeve assembly of claim 15, wherein at least one cavity is defined in the sleeve wall, adjacent to the heating element, for allowing release of mineral buildup from the heating element.

22. The sleeve assembly of claim 13, provided as a retrofit kit for installation into water heaters for granting energy efficiency.

23. An energy efficient water heater, substantially as described herein by way of example and with reference to the drawings.

24. A method for efficiently heating water in a water heater, said method comprising: a. providing a water heater comprising: a thermally insulated storage tank; water supply means including a cold water inlet on said tank and a hot water outlet, and including a plurality of valves; and a removeably insertable sleeve assembly within said tank, said sleeve assembly comprising a sleeve wall capable of delimiting a quantity of water within said assembly, wherein said sleeve wall includes at least one opening for fluid communication with the contents of the storage tank, and wherein said sleeve wall surrounds and contains therewithin: i) an electrical heating element; ii) a temperature sensor; and iii) a hot water discharge pipe connected to the hot water outlet on said tank; wherein the majority of the discharge pipe is present within the sleeve such that water passing through the hot water discharge pipe does not cool; and wherein the inlet of said discharge pipe is located within the upper portion of said sleeve, and b. operating said water heater by providing electricity to said water heater. For the Applicant: Zisman & Co. C: 1857 1 1