US20040187862A1

US20040187862A1 - Portable solar heated water server

Info

Publication number: US20040187862A1
Application number: US10/403,471
Authority: US
Inventors: Victor Cobos
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-03-31
Filing date: 2003-03-31
Publication date: 2004-09-30

Abstract

A solar heated water server is a batch type solar water heater that is integrally mounted on a wheeled chassis. The server enables a person to fill the solar heater with water through an externally pressurized hose that is then disconnected. The server can then be moved by hand into a position which best captures sunlight. Said chassis is constructed to allow adjustment for solar angle as well as azmuth. The solar water heater is constructed with curved internal reflectors that allow for the capture of a wide angle of diffuse radiation and also reflect direct sunlight onto the absorber tank over a wide azmuth angle. When the water is hot, the server is then wheeled to the point of use and reconnected by a hose to a source of pressurized cold water. The hot water can then be forced out by and mixed with cold water. Plumbing, including all necessary valves and connectors are integrally built into the solar heated water server enabling the yield of a usable quantity and temperature of water at a desired location.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Field of search. U.S. C1. [0001]
126/600; 126/608; 126591; 126/592; 126/431; 126/627; 126/640; 126/270; 126/440; 126/639; 136/244 [0002]
The following references are cited, all U.S. patent Documents: [0003]
U.S. Pat. No. 4,130,107 December 1978 Rabl, et al [0004]
U.S. Pat. No. 4,328,792 May 1982 Shores [0005]
U.S. Pat. No. 4,459,973 July 1984 Royer [0006]
U.S. Pat. No. 5,507,275 April 1996 Clark [0007]
U.S. Pat. No. 6,201,181 March 2001 Azzam, et al[0008]

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

The present invention pertains to heating of water by solar energy and with the utilization of the water thus heated. More particularly, the invention provides for the rapid heating of a batch of water sufficient for the accomplishment of a task normally requiring hot water and for delivering that water to any desired location.

Solar water heaters are well known and they are of various design. The utilization of solar energy is well established and, within the art, it is recognized that mobility is fundamental to maximize the capture of solar radiation. Either a solar collector must move, or reflectors must be moved, in order to present the best angle of incidence to the radiation eminent from Sun as the solar altitude angle and solar azmuth angle change seasonally and hourly. The problem of mobility is more difficult when sunlight is used to heat water because flexible plumbing is needed to allow the collector to move to follow the sun while transporting the heated water or a heat transfer fluid to the point of use. A solar powered fluid heating device is disclosed by Shores in U.S. Pat. No. 4,328,792. Shores provides for the movement of a reflector and immobile absorber plumbing. Shores recognizes that, because his invention only moves on one axis, his collector is not very efficient at high solar angles. A linear parabolic reflector is used by Shores to concentrate solar radiation. This introduces the danger of overheating, therefore requiring that the fluid being heated be circulated constantly.

Concentrating radiant energy collectors capable of limiting the amount of energy captured are disclosed in U.S. Pat. No. 4,130,107 by Rabl and Winston. Although these non-imaging collectors allow for the capture of virtually all energy incident thereupon over a wide angle, they are limited. At higher angles of incidence upon the absorber, absorption of radiation decreases. Increasing reflection of radiant energy at higher angles of incidence by transparent covers used to provide a static insulating layer of air, as is the practice in most solar collectors, also limits the time during which these collectors function efficiently. It is therefore necessary to refocus these collectors periodically and repeatedly during the day. The various shapes of the reflecting surfaces disclosed by Rabl and Winston are complex and difficult to construct in practice.

A moveable solar collector is disclosed by Royer in U.S. Pat. No. 4,459,973, which uses a hydraulic device and rollers to move the solar collector into the building for space heating. Royer requires significant alteration to the construction of the building within which his invention is to function. Motive power is supplied by human labor in the Royer invention.

Most solar hot water heaters used in this country today are the flat plate type that allow for the capture of large areas of sunlight. The efficiency of these fixed collectors declines rapidly as the angle of incident sunlight increases. Typically, these flat plate systems will not withstand the pressure of household water systems and need to transfer heat they capture from the sun to the water to be used via a separate closed loop of circulating fluid. These systems are complicated by the requirement for heat exchangers, seals and pumps, all of which raise the cost of the systems and eventually require maintenance. The typical system also requires sensors, solenoids, motors and wiring, as well as electricity to operate. The hot water tank is pressurized by the cold water supply in this typical residential system. It is stored in an insulated tank, which also contains auxiliary heating devices powered by gas or electricity.

Another type of solar water heater is the batch type, which typically consists of a large tank, which is the absorber. Batch type heaters typically heat usable water directly. Batch type heaters capture smaller areas of sunlight in relation to the volume of water they contain than do the flat plate type and typically take longer to reach a desired temperature. Although most batch type heaters use internal reflectors, their effectiveness is limited by their rigid deployment so that only during that time of day when direct sunlight strikes them at the proper angle is the absorber irradiated.

Freeze protection is a major concern for solar water heaters of all types. Many systems provide for drainage of the system into a holding tank during freezing nights. This drain-down solution to the freezing problem further complicates these systems. A tank, solenoids, sensors, pumps, and the electricity to operate them are required. Royer suggests moving the whole collector indoors to give up any accumulated heat to that space. To move conventional collectors indoors would require modification of the building as in the Royer invention.

A solar shower is disclosed in U.S. Pat. No. 5,507,275 by Clark. The Clark invention is filled and pressurized through a hose and heats the contained water by sunlight. The Clark invention captures a very small area of sunlight and would take a long time to heat. This invention is also missing insulation to retain the heat. Clark does not enable his solar shower with mobility and, once filled and heated, would have to be used in place. Clark does provide in his invention the apparatus for mixing of hot and cold water by the user. No connection to electricity is required by the Clark invention. The heated water is extracted by the pressure of the cold water delivered through a hose from an externally pressurized source.

In U.S. Pat. No. 6,201,181 Azzam et al. disclose a portable wheeled platform for adjusting a photovoltaic solar panel and also to carry the batteries wherein the energy captured is stored in the form of electricity. The Azzam invention provides for the rapid focusing of the solar collector by hand at any time. A determining limit to the size of the Azzam invention is the bulk and weight of the device, since it must be moveable by hand by people of average strength.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide for the heating of water by solar energy and for the delivery of that heated water by human labor to a point of use remote from the location at which it was heated by the sun. The invention also provides for the mixing of hot water with cold water to a desired temperature. The solar collector is configured so that curved reflectors focus reflected sunlight on to the surface of an absorber tank filled with water. The focus of sunlight by the curved reflectors is non-imaging thereby enabling the collector to remain in focus for up to three hours. The temperature of the water in the tank typically reaches 165° f. and when mixed with cold water at point of use, can yield enough heated water to take a shower or to wash a load of laundry or for washing dishes. On a clear day during most of the year the invention can be redeployed and reheated to accomplish all three.

Another object of the invention is to deliver hot water to a location without need for dedicated plumbing. The absorber tank must be filled with water through an externally pressurized hose. Only a pressurized cold water outlet is necessary near the point of use to reconnect the solar hot water server and to force out the hot water with cold and mix it to a desired temperature. The Solar hot water server can easily be drained to lighten it for moving it to a different location or to prevent damage due to freezing. The invention can also be moved indoors full of hot water so as to give up the stored heat to space heating.

Advantages of the invention will be shown by the more detailed description in which the arrangement and functioning of the apparatus are explained in conjunction with the drawings in which the parts referred to are labeled by corresponding numerals.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is an isometric drawing showing the invention in position to capture sunlight. [0023]
FIG. 2 is a top view of the invention. [0024]
FIG. 3 is a back elevational view of the invention. [0025]
FIG. 4 is a East side elevational view of the invention. [0026]
FIG. 5 is a front elevational view of the invention. [0027]
FIG. 6 is a horizontal section of the invention shown in FIG. 5. [0028]
FIG. 7 is an oblique drawing of the internal reflectors. [0029]
FIG. 8 is a ray-tracing diagram showing the capture of sunlight over a 45° azmuth angle. [0030]
FIG. 9 is a ray-tracing diagram showing the capture of sunlight over a 45° azmuth angle.[0031]

DETAILED DESCRIPTION OF THE INVENTION

The invention, as it is depicted in FIG. 1 is a highly efficient solar powered collector for heating water that has been mobility-enabled by the integral wheeled chassis upon which it is manually deployable. The apparatus is additionally enabled to serve water at a desired temperature by providing for the mixing of hot and cold water. [0032]
The solar water server consists of a batch type solar water heater small enough to be easily moveable by hand, yet able to deliver a quantity of hot water sufficient for the performance of normal household tasks such as dishwashing, bathing, washing clothes, etc. The quantity of hot water delivered at a temperature for bathing (110°) is greater than the quantity heated and moved because cold water must be added to lower the temperature from 165°. This higher temperature is achieved in a short time (two to three hours depending on the season), by concentrating sunlight upon the absorber tank. [0033]
Routine daily operation involves manually moving the invention out through the average residential doorway in the morning and into direct sunlight. The invention is deployed manually by grasping the [0034] handles 17 and tilting the machine, rolling it upon its wheels 15. The ideal positioning of the invention to begin heating is that seen in FIG. 1, with the sun directly over the head of the viewer. FIG. 2 depicts the top of the invention as it appears to the operator who would grasp the handles 17. To begin heating the water, the operator would move the invention so that the transparent cover faces toward the sun and adjusting the positioning so that the sun is over the left side (also the operator's left side). Depending on the sun altitude angle at the time of deployment, the invention can be tilted back to rest upon the sun altitude focus supports 10 a & 10 b, or even laid flat upon the backside when the sun appears high overhead. A cross-section of the invention FIG. 6 depicts how the absorber tank 1 is filled with water via an externally pressurized water hose that is connected to the invention at the water inlet hose fitting 7. Opening the inlet valve 11 allows water into the absorber tank 1. Air is expelled from the tank by opening the hot water valve 14 as pressurized cold water enters the tank. When the tank is full the water inlet valve 11 and the hot water valve 14 are both closed and the supply hose is disconnected.
The acceptance and capture of the incident sunlight over an azmuth angle of 45° is maximized by configuring the reflectors and absorber tank as shown in the ray tracing diagram shown in FIG. 8. Highly [0035] polished aluminum reflectors 2 are rolled to a curved profile and positioned so that they nearly surround the absorber tank 1 in an involute configuration. These reflectors 2 reflect sunlight onto the area of absorber tank that would typically be shaded and insulated in the standard batch type solar water heater. This assures more rapid heating as the tank receives energy over a much higher percentage of total surface area.
FIG. 7 shows how the [0036] internal reflectors 2 are constructed by rolling a sheet of highly polished aluminum to a small radius at one edge and to a much larger radius at the opposite edge. The curvature of the reflector 2 is a bi-radial cylindrical section formed by placing circular cylinder of radius r1 within the circular cylinder of radius r2 with their axis parallel and their diameters coinciding along the projected line a-b. The curvature changes from r1 to curvature r2 along a-b when sections of the two cylinders are conjoined at this line a-b, which lies on a plane cotangent to both the cylinder of radius r1 and the cylinder of radius r2. The profile of the cylindrical section thus formed is not parabolic. The bi-radial profile of the reflector functions as well as a parabolic reflector and in practice has the advantage of being easy to construct using commercial sheet metal rolling tools.
As shown in FIG. 8, both the large radius R[0037] 1 and the small radius R2 are shorter than are the corresponding large radius R3 and small radius R4 respectively in FIG. 9. Both in FIG. 8 and in FIG. 9, despite the difference in the radius of their curved reflecting surfaces, the capture of sunlight by the absorber tank appears total.
Looking at FIG. 5, we will refer to the horizontal portion of the [0038] solar heater body 5 nearest the ground as the bottom. The like horizontal portion above which the handles 17, the hot water valve 14 and the cold water valve 12 are shown to project, we will refer to as the top. Both the bottom and the top have flat reflectors 16 disposed internally so as to reflect toward the ends of said tank. The absorber tank is separated from these flat end reflectors leaving an insulating air space between said reflectors and the absorber tank. The absorber tank 1 is suspended in the center of the solar heater by the tank supports 20. In practice the affects of motion of a full tank of water generate substantial stress at the points of attachment of said tank supports to the apparatus. Conflicting requirements to the sturdy tank supports called for are primarily the need to prevent said supports from shading the absorber tank and secondly the need to prevent them from conducting heat away from said tank.
In FIG. 6, thermal insulation [0039] 6 is shown to completely fill the space between the reflector 2 and the outer solar heater body 5, the entire inside surface of the solar heater body is insulated including the flat top and bottom sides. The solar heater body 5 is fabricated sheet metal formed so as to provide a frame to hold the inner glass cover 3 and the outer glass cover 4 in separation, thus trapping static air to provide thermal insulation at the transparent surface as is the common practice in the industry.
When the solar powered server is properly deployed in sunlight, as time passes the sun will appear to travel across the face of the collector (from left to right on the northern hemisphere) and will stay in focus for up to three hours (equivalent to 45° azmuth angle) as seen in FIG. 9. Typically on a clear day, the invention will not need repositioning to fully heat a batch of water. When the water is hot, the invention can be wheeled to the desired point of use and placed upright. [0040]
To move the invention, the sun altitude focus supports [0041] 10 a and 10 b are rotated inward. This repositioning of the right side sun altitude focus support 10 a is seen in FIG. 2. Repositioning of the left side sun altitude focus support 10 b is seen in FIG. 4. FIG. 4 shows the invention standing upright and resting upon the footplate 9. In cold weather the invention should be moved indoors to prevent freezing. It can also be brought inside and the heated water retained, thus providing space heating as the hot water cools.
FIG. 3 best depicts the plumbing and associated valves and fittings by which the invention is filled with cold water, and by which the heated water is extracted and mixed to a desired temperature and rate of flow. To extract the heated water an externally pressurized water supply hose is attached to the water inlet hose fitting [0042] 7 and the water inlet valve 11 is opened. The flow of incoming water is split at the tee fitting 18, thus pressurizing both the cold water to the cold water mixing valve 12 and the water in the tank. By manually adjusting the opening of the cold-water valve 12 while alternately adjusting the opening of the hot water valve 14, a desired temperature and flow of mixed water is forced out through the mixed water spigot 13. This spigot can be rotated outward to discharge water into a sink. Hot water can also be supplied to an appliance such as a dishwasher or a washing machine by connecting the appliance hot water supply hose to the mixed water spigot 13. A hose can also be attached to the mixed water spigot with a showerhead at the opposite end of it for bathing
The solar heated water server as described herein and as depicted in the drawing figures is by no means the end product. Many details can be altered and changes made within the scope of the invention without departing from the spirit of the invention in general. The invention as disclosed here does not show the particulars of how the apparatus is fabricated nor does it show features desirable for its commercialization. The embodiment of the invention as presented here is to be taken as illustrative and not as restrictive. All changes made which fall within the equivalency of the meaning and scope of the following claims are intended to be embraced therein. [0043]

Claims

What I claim as my invention is:

1. A portable hand operated solar powered water heating and service device comprising:

(a) A solar water heater capable of heating a usable quantity of water within a cylindrical tank capable of withstanding average residential water pressure and coated so as to absorb solar radiation. Said absorber tank is positioned within the apparatus so that it receives direct sunlight through a transparent surface of the outer body of the apparatus.

(b) Curved reflectors and, or, flat reflectors are provided and are positioned within the apparatus so as to reflect an additional area of sunlight onto the remaining surface of said absorber tank not exposed to the direct solar radiation.

(c) Thermal insulating material is disposed in contact with the backside of the reflectors so as to completely fill the space between said reflectors and the inside surface of the outer body of the solar water heater. The transparent surface is, by design, as large as practicable in order to maximize the solar aperture. A second transparent surface made of glass is placed within the outer body in a plane parallel to, and separated from, the plane of the outer transparent surface. A structure formed at the periphery of the outer body holds the inner transparent glass surface in separation from the outer transparent surface so as to trap a layer of static air to provide thermal insulation at the transparent surface of the solar water heating apparatus.

2. The device of claim 1 rendered portable by hand by integrally mounting said solar water heating and service device upon a chassis to carry the device including:

(a) One or more wheels are provided of a diameter enabling the traverse of natural terrain by the apparatus when operated by adults of average strength. Multiple wheels are deployed in a manner enabling the operator to easily rotate the invention toward the sun, thereby adjusting for solar azmuth angle.

(b) Adjustable retractable supports are provided and are deployable in order to focus the solar water heater upon the sun at the time of deployment, thereby adjusting for solar altitude angle.

(c) Said chassis additionally provides a footplate or feet enabling the upright positioning of the device when moved indoors so as to occupy less space and in which position the hot water is conveniently dispensed.

3. The portable solar water heating device of claim 1 further enabling the operator to fill the apparatus with water at any location where a supply of pressurized water is available through a hose and after the water has been heated in the sun; to extract the heated water by attaching the apparatus to a hose at a location distant from the location where it was heated, at a temperature and rate of flow, of the operator's choosing via a plumbing system including:

(a) A hose connection fitting enabling the attachment of an externally pressurized cold water supply hose through which the absorber tank within the device can be filled. By reconnecting a like pressurized cold water supply hose to the same fitting at the point of use, the heated water is forced out. An additional hose connection is provided at the discharge end of the system to provide for the delivery of heated water.

(b) A water inlet valve is provided to hold the water within the tank, thus allowing the detachment from the externally pressurized cold water hose.

(c) A tee fitting divides the flow of cold water entering from said hose. Water is thus delivered to both the absorber tank within which the water is heated and also delivered to the cold water side of the temperature and flow-rate adjustment device.

(d) One or more valves are provided in fluid communication with both the hot water from the absorber tank and the incoming cold water to enable the operator to adjust the temperature and rate of flow of the water served.

(e) Provision for service of the heated water is via a mixed water spigot. Said spigot swings out over the edge of the apparatus in order to discharge water into a sink or other container directly. Said mixed water spigot also provides for the attachment of a hose from an appliance such as a dishwasher or from a shower.

4. The device of claim 1 and of claim 2 combining the outer body of the device of claim 1 with the chassis of the device of claim 2 in combined fabrication by the inclusion and addition of:

(a) Reinforced supports are added to the outer body of claim 1 in order to mount the wheels of claim 2 directly onto said outer body.

(b) The body of claim 1 is provided with reinforced mounts to install handles to function as those provided by the chassis of claim 2.

(c) Reinforcing is added to the body of claim 1 at the proper locations to mount the solar angle focus support tubes of claim 2 directly thereto.

(d) The bottom of the outer body of claim 1 is constructed so that the device can rest directly thereupon, or so that the footplate or feet of claim 2 can be directly attached thereto.

(e) Reinforcing and stiffening is added to the outer body of claim 1 to enable said body to bear the weight of the device as is borne by the chassis of claim 2.