Self regulating heating system and method for a pool, such as a swimming pool

Abstract

A self regulating system and method for heating a swimming pool, using solar energy. There is a cover member which is placed over the surface of the swimming pool and water from the swimming pool is pumped cyclically through flow paths in the cover section. Solar energy directed to the top surface of the cover section heats the water that flows through the cover section. There is a solar power pumping and control system by which solar energy is utilized to supply electrical energy to a battery and also to a motor of a pump. A control section causes the cyclical operation of the pump so that the pumping cycles are related to the intensity of the solar energy which is being transmitted to the system at that time.

Description

BACKGROUND OF THE INVENTION

a) Field of the Invention

The present invention relates to the heating of a body of water, such as a swimming pool, and more specifically relates to a system and method by which the system and method is self regulating so that it can optimize its operation relative to the solar energy which is available, without human intervention.

b) Background Art

Pool heaters have been in use for many years. One type of pool heater is comprised of an electrical heater unit that heats the water utilizing conventional power. A second type of pool heater is comprised of a passive cover that allows solar energy to enter the pool but retains the solar energy within the pool. Yet another type of pool heater is comprised of a solar heater unit that is positioned away from the pool (e.g. on the roof of a house) wherein water is pumped to the solar heater and then returned.

There are also a number of systems for heating the water in a pool using solar energy where a cover with flow paths is placed on the top surface of the pool. Then water from the pool is circulated through this cover so that it is heated by solar energy and returned to the pool.

There are also systems where solar energy is used to energize a pump by using a photovoltaic cell to derive electrical energy from the solar energy to drive the pump.

The embodiments of the present invention are directed toward providing a system and method of heating a pool such as a swimming pool where the system and method can utilize the solar energy efficiently and also so that the system is self regulating so that it does not require human attention and/or intervention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of an embodiment of the invention, showing the cover section in plan view, and also showing the power and pumping section;

FIG. 2 is a side elevational view, partly in section, showing a swimming pool with the cover section of the embodiment located in its operating position on the surface of the pool and also showing the power and pumping section;

FIG. 3 is an isometric view of a panel of the cover section;

FIG. 4 is a cross sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a top plan view looking down on the panel but not showing its top cover sheet;

FIG. 6 is a schematic view of a first embodiment of a power and pumping section;

FIG. 7 is a schematic view similar to FIG. 6 showing another embodiment of the power and pumping section;

FIG. 8 is an isometric view of a support and power unit to contain certain components and also to provide various angular orientations of a solar power section;

FIG. 9 is a view similar to FIG. 8, but showing two support members of FIG. 8 separated from one another;

FIG. 10A is a semi schematic end view of the support and power unit of FIG. 8, with various sides and angles of the surfaces being illustrated and given designations for purposes of explanation;

FIGS. 10B-10E are simplified views somewhat similar to FIG. 10A, showing various arrangements to provide different angular orientations for the solar power section;

FIGS. 11, 12, 13, 14 and 15 are side views, partly in section showing various fluid connections between the panels of the cover section;

FIG. 16 is a side elevational view, partly in section, showing a method by which the cover section could be removed from, or moved onto the surface of the swimming pool;

FIG. 17 is a side elevational view showing the panels of the cover section stacked in a stowed configuration.

FIG. 18 is a top plan view of a panel of a fourth embodiment, with the cover sheet removed for purposes of illustration;

FIG. 19 is a sectional view taken along line 19 of FIG. 18;

FIG. 20 is a side view of an inlet end portion of a main feed conduit of the fourth embodiment; and

FIG. 21 is a sectional view of one of the outlets in the panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is believed that a clearer understanding of the embodiments of the present invention will be obtained by presenting initially a brief description of the main components of the first embodiment of the invention and then describing the basic operation of this first embodiment. After that there will be a more detailed description of the various components, as well as a description of other embodiments and/or modifications.

In describing generally the first embodiment, reference will first be made to FIGS. 1-5. With reference to FIG. 2 there is a swimming pool 10 which for ease of presentation in the drawings is simply shown as two wall portions 12 of a surrounding structure 13 of the pool 10. The structure of the pool provides a pool region indicated at 14 which is shown as containing water 16 having an upper water surface 18. The system 20 of this first embodiment of the present invention comprises two main components. First, there is a cover section 22 which is positioned at the surface 18 of the water 16, and this provides both an insulating and heating function for the water 16 in the pool. Then there is a power and pumping section 24 which circulates water through the cover section 22 in a manner to cause this water to be heated.

We will first turn our attention to the cover section 22. This cover section 22 comprises a cover structure 26 which in this embodiment comprises a plurality of rectangular panels 28 which extend over substantially all of the water surface 18, or at least a substantial portion thereof. These panels 28 are placed with their adjacent side edges spaced a short distance from one another, and these are connected to one another by sheets 30 and/or straps 31. Also, there are tube connections 32 between adjacent side edges 36 of the panels 28 to enable water to flow through the panels 28. At the left hand of the cover structure 26 there is a water inlet 33 to direct water into the left panel 28 to flow through the panels 28. There is an outlet 34 at the other end of the cover structure 26. Quick disconnect couplings 35 are provided at the water inlet and outlet 33 and 34.

The straps 31 and the disconnect couplings 35 make the deployment and retrieval of the cover section 32 easier. The straps 31 span a pair of adjacent panels 28, with the straps attached at opposite side portions of adjacent panels, but not at points in between. The straps make it possible to lift a pair of cover sections at a time out of the water.

With reference to FIGS. 4 and 5, each panel 28 is made of a rectangular base plate 38 which is made of a buoyant and heat insulating material, such as, for example, a closed cell foam or a thermoplastic foam with no or low absorption. A network of flow paths 40 are provided in the upper portion of each plate 30, with these paths 40 being in a form of grooves 40 which are shown as having a “V” shaped cross section, but these could be square, rounded, etc. Also, the side portions of the two panels 28 are formed with side openings 41 to connect with the tube connections 32 and enable the water to flow from the paths 40 in one of the panels 28 to an adjacent panel 28. At the upper surface of each base plate 38 there is a cover sheet 42 that is bonded to the upper surface of the panel 28 to seal the paths 40. Also, the sheet 42 provides an upper solar energy absorbing surface region 44 which absorbs solar energy and conducts this as heat into the water flowing through the paths 40. This sheet 40 could be made in different forms. One possibility is to make the sheet 42 a membrane 42. Also, a solid sheet of laminar plastic, covered by a thin layer of acrylic (for UV stability) could be used. In addition, a thinner polystyrene plate could be used below this to form a sandwich construction making the sections 28 strong enough so that the pool cover 22 could also be used as a security cover to prevent children from drowning.

With reference back to FIG. 2, at the left hand side of the drawing of FIG. 2, there is shown an inlet hose 46 which takes in the water and directs it into the nearest panel 28. The water flows sequentially through the panels 28 to be heated until it reaches the outlet 32, and at the right end of the FIG. 2, there is shown an outlet hose 48 that receives the water and directs the water to a lower elevation in the water 16. The panels 28 can be connected in a series so that the heated water flows from one panel 28 to the next and exits the last panel via outlet 34. Alternatively, the water from the pool is fed into all cover sections in parallel so that the heated water exits outlets 34 in each panel 28. This will be described later in this text with reference to FIGS. 18-21. Thus back pressure in the system can be reduced and the pumping of the water can be accomplished more easily.

As indicated previously in this text, the second main component of the system 20 is the power and pumping section 24 that is shown in its operating position in FIGS. 1 and 2. To describe the main components of this section 24, reference is first made to FIG. 6. In FIG. 6, there are shown the four main components of this section 24, these being the following: a solar power section 50, a battery section 52, a pump section 54, and a control section 56.

With regard to the solar power section 50, this is shown not only schematically in the drawing of FIG. 6, but also is shown in FIGS. 1 and 2. This solar power section 50 comprises a photovoltaic panel which converts the solar energy into electrical energy and has a power connection to the battery section 52. The battery section 52 comprises a storage battery. The pump section 54 functions (as it's name implies) to take the water 16 from the pool 14 and pump it through the hose 46 to travel through the cover section 22 to be heated by the sunlight that reaches the cover section 22. In FIG. 2 the pump section 54 is shown as a submersible pump connected by wire 55 to the other components in the power and pumping section 24. The control section 56 operates to close and open a switch 70 to cause the pump section 54 to operate or to shut it down, this being done in cycles, with each cycle having a pumping period and a non-pumping period. The manner in which it is accomplished will be explained in the following paragraphs.

With the main components of the system 20 having now been described, let us now turn our attention to the mode of operation, after which there will be a more detailed description of the components and various features of the embodiments of the invention.

Let us assume that it is a sunny day and a higher level of solar energy is being transmitted to the solar panel section 50, with the result that the water which is then present in the cover section 22 warms up more rapidly. In that situation, to obtain optimum heating efficiency it is desirable that the water which has been heated up to a desired temperature should be moved within a reasonable time period from the cover section 22 and delivered back to the pool 10, this being accomplished by the pump section 54 pumping a second quantity of water into the cover section 22 to be heated and to displace the now heated water in the cover section 22. That would mean that the cycles of the pump section 54 being turned on and off should occur with shorter time intervals between pumping modes.

Now, let us further assume that it is a rather cloudy day where there is lower energy level of sunlight making its way to the cover section 22 so that the water in the cover section 22 heats up more slowly. It is a waste of electrical energy to pump another amount of water into the cover section 22 prematurely to displace the water which had been warmed very little. Therefore, the time intervals between pumping cycles should be greater. In the present invention, to operate the system in the most efficient manner, the timing of the pump cycles is automatically regulated so that the timing of the cycle intervals matched the intensity of the solar radiation.

To comment further on this mode of operation the control section 56 is operatively connected at least to said pump section 54 to cause the pump section 54 to operate in cycles to first circulate the water through the cover section 22 for a pumping period of the cycle and turn off the pump section for a non-pumping period of the cycle. The control section is arranged to be responsive to a value or occurrence related to intensity of the solar energy directed to the cover section 22 and to the power and pumping section 24, so that during periods of greater intensity of the solar energy the non-pumping periods of the pump section 54 are of lesser duration and during periods of lesser intensity of the solar energy, the non-pumping periods are of greater duration. Thus the system 20 is self regulated to take advantage of periods of greater solar intensity when water in the cover section is heated more rapidly, by having the pump section operate in more frequent cycles to re-circulate more heated water, and during periods of lesser solar intensity the cycles are of less frequency.

With further reference to FIG. 6, the solar power section 50 has at a connecting location 58 a direct connection 59 to the battery at 60, to the motor at 62 in the pump section 54, and to the control section 56 at a terminal location at 64 labeled as “V_C” in FIG. 6. Then the connecting location 58 of the solar cell 50 also connects to a diode 66 to another location 68 on the control section 56, this connection being indicated at “p” in FIG. 6. Also, the motor 54 connects through an off/on switch 70 that has a second connection at 72 to the solar power section 50, and also connects to a second terminal location 74 on the battery section 52.

The pump section 54 would consume more power than the power which the solar power section 50 could generate, even on a rather bright sunny day. For example, the maximum power output of the solar power section 50 could be 5 watts and the battery section 50 could consume, for example, 20 watts in its normal mode of operation. This ratio obviously could be changed, and the ratio of the peek power of the solar energy section 50 at peak operating periods could be anywhere from 10%, 20%, 30%, 40%, 50%, 60%, 70%, or possibly higher. This would depend upon a number of factors to obtain a proper balance among the operating components to optimize the operation. Therefore, when the battery section 52 is fully charged and a cycle is starting, the pump section 54 will begin consuming electricity, so that energy will be drained from the battery section 52, so that the voltage at the battery terminal 60 will begin dropping and will continue to drop during the pumping period. Thus, during the time period when the motor 54 is operating to pump the water, the motor is taking energy not only from the solar power section 50, but it also is taking power from the battery section 52. This will cause the voltage at the battery terminal at 60 to keep dropping until the battery voltage drops to the lower level of, for example, 11 to 11½V. When this happens, the drop in voltage is detected by the control section 56 at the location 64 (i.e. the terminal V_C), and this causes the control section 56 to open the switch at 70 to cause the motor 54 to stop operating, thus completing the pumping cycle.

When the motor 54 does stop operating, the solar energy which is imparted to the solar power section 50 continues to be delivered to recharge the battery section 52. The solar power section 50 will continue to charge the battery section 52 until the voltage reaches a preset level of, for example, 13 to 13.5V, and at this time this is detected by the control section 56, which starts the motor 54 then which starts operating again to start a second pumping cycle.

One of the problems associated with starting up electric motors is that when the motor is just starting to operate, it draws a surge of current to get the motor started. Then after the motor has reached a certain level of RPM's, the back emf (i.e. back electromagnetic force) in the motor reduces the amount of current. Therefore, the battery must be sized to have sufficient capacity to meet the higher current demands of this surge of power.

To explain the operation of this first embodiment more completely, there is provided below Table I which illustrates a simple program for the microprocessor in the control section 56.

TABLE I
1 SET voltage at which pump is started VR
  (typically 13-13.5 V)
2 SET voltage at which pump is stopped VO
  (typically 1 . . . 5-12 V)
3 MEASURE present circuit voltage VC
4 IF VC ≧ VR THEN open switch 70 ELSE
  RETURN to line 3
5 MEASURE present voltage VC
6 IF VC ≦ VO THEN close switch 70 ELSE
  RETURN to line 5
7 RETURN to line 3

The control section 56 will keep measuring the present voltage V_C in the bottom Section 53 until the charge from the solar power section raises V_C to the set level V_R or above. The pump section 54 will then start and the control section 56 resumes measurements of V_C. When the power consumed by the pump section 54 has brought V_C to the set level V_S or below, the pump section 54 stops. The control section will again measure V_C in anticipation of the next run cycle.

The above circuit is simple but in practice, as discussed above, many pump motors draw a high amperage current when they start, so that here is an abrupt momentary drop in voltage, and this could shut off the pump as it tries to start. Therefore, a second embodiment of the power and pumping section 54 is shown in FIG. 7. which shows a block diagram of a modified power circuit that circumvents this problem. It uses the same components as the circuit shown in FIG. 6, but inserts another diode 76 and a resistor 78 between the solar panel 50 and the battery section 52. A direct input connection 80 between the solar power section 50 and the control section 56 is also added. This modification permits a separate measurement of battery voltage V_B at input connection 82 to the controller and solar panel voltage V_S at the input connection 84. Table II illustrates a program for use with this circuit.

TABLE II
1 SET battery voltage limit VL for starting
  pump (typically 12-13 V)
2 SET solar panel voltage ΔV for starting pump
  (typically 0.1 to 0.5 V)
3 Set time x for pump ON (typically 10-60 seconds)
4 Measure battery voltage VB
5 IF VB ≧ VL THEN measure solar panel voltage
  VS ELSE return to line 4
6 IF VS ≧ (VB + ΔV) THEN open switch 70
  ELSE return to line 4
7 Wait x seconds THEN close switch 70
8 Return to line 4

In this case all measurements are made when the pump is off, so that a current drop when the pump starts will not affect measurements. The control section 56 waits until the battery section 52 has been sufficiently replenished to reach voltage V_L, then checks for the presence of solar radiation as indicated by a solar panel voltage V_S which is higher than the battery voltage by ΔV or more. If this is the case the pump starts and runs for a preset time “x” and shuts down. The controller then resumes measurements of battery voltage, repeating the cycle when the conditions permit. The time “x” could be varied by the control section in response to the level of the solar energy so that when the solar energy is more intense the time “x” would be longer and when the solar energy is less intense times “x” is less.

Using the described cycling mode and circuits achieves three objectives:

(1) Most low-cost commercial 12V pumps are not designed for running continuously. Cycling the pump avoids overheating and extends pump life. Although the water circulates more slowly, this is offset by a longer dwell time in the cover, with a higher water temperature at the exit.

(2) Solar panels are expensive. Cycling the pump permits the use of a solar panel of modest size and cost.

(3) The circuit is self-regulating without the need for additional sensors. Water is only circulated when there is sufficient solar energy to heat it.

As indicated above, it is obviously possible to use more sophisticated programming, e.g. introducing different voltage thresholds for different pump run times and/or rest times between cycles. This may help to minimize unnecessary current drain in the circuit, thus maximizing power management. It is equally obvious that there are many possible variations in actual circuit design. It may for instance be desirable to design the circuit so that the pump will not run when it is removed from the water, to spare pump life, which can be achieved by measuring the amperage of the pump.

Let us now turn our attention back to the cover section 22 and more particularly to the panels 28. It was indicated that the flow paths were provided in the form of grooves 40 which were made in the base plate 38, and reference is again made to FIGS. 3, 4 and 5. To elaborate on this further, these grooves 40 are desirably formed in the form of a grid or grids which could be designed in a variety of different patterns. In FIG. 5, these grooves generally designated by the numeral 40 are shown in the form of two grids. In each grid, there are laterally extending grooves 88, and the ends of these grooves 88 are connected at their end portions to rear and forward edge grooves 90 and 91, respectively, extending along the opposite side edges of the panel 28. It will be noted in FIG. 5 that two of the edge openings 41 (i.e. those appearing in the bottom part relative to those showing in FIG. 5) are outward openings 41 located further outward toward the ends of the panels 28, while two other on an opposite side which are located at a more central location. Thus, the flow is through the outward openings 41 into the rear edge groove 90 which feeds the water into the laterally extending grooves 88 to flow forwardly into the forward edge groove 91 to flow to the central openings 41 to the next forward panel.

The plate 38 of each section is made of a buoyant and insulating material. An example of a suitable material is a thermoplastic foam with no or low absorption of water. On the upper surface of the plate there are the previously mentioned cut or molded grooves or paths 40 which will form water channels. The grooves 88 and 90 are interconnected to form this grid 32 in a manner which distributes the flow of water throughout the entire available area of the cover section 22. It may be desirable to use several separate grids.

Grids may be designed in many different patterns. Generally there is a compromise between efficient water distribution, ease of emptying the cover when it is pulled out of the pool, and avoiding a large number of connections between cover sections. The grids communicate to the outside of the plate through openings 41, for connecting the inlet and outlet manifolds, and for interconnecting several cover sections. The depth dimension of these grooves 40 could, depending on various factors, have a depth dimension les or greater than the width dimension of the grooves or paths 40 at the top of the grooves, and within the broader scope, could be 90%, 80%, 70%, 60%, 50%, 40%, 30% or 20% of the width dimension or less or possibly 120%, 140%, 160%, 180%, 200% of said width dimension or greater.

The aforementioned sheet 42, which seals the upper surface of the grids 86 may be made of plastic or rubber film, or of coated or impregnated fabric, or as a stiff or moderately yielding plate. The sheet 42 is attached to the base plate 38 using adhesives, welding or other suitable techniques. If the water is to be heated by contact with the sheet 42 above, a dark energy absorbing color is chosen for the sheet 42. Alternatively the sheet 42 can be transparent, and in this case the grooves have the energy collecting surface.

A third embodiment of the present invention is shown in FIGS. 8, 9 and 10A-10E. There is a power support section 94 to contain and/or support components of the solar panel section 50. In the following description this section 94 will be called simply the “support section 94 ”.

This support section 94 comprises a major support member 96 and an adjustment support member 98. (See FIGS. 8 and 9 ). These two support members 96 and 98 can be connected together in a manner to provide support for the solar power section 50 in five different angular positions, beginning with a nearly horizontal 15° position (the 15° angle and the other angles being measured relative to a horizontal axis), a 30° position, a 45° a position, a 60° position, and possibly a 75° position.

The two support members 96 and 98 are in the form of a regular prism having a uniform cross sectional configuration along a longitudinal axis. The cross section of each of these members 96 and 98 is that of a right triangle, with the major support member 96 being in a 90°-60°-30° right triangle, designated the “major triangle”, and the adjustment support member being in a 90°-75°-15° right triangle, designated the “adjustment triangle”. Since the critical functional features of these two support members 96 and 98 are their exterior surfaces, the following discussion will simply refer to their surfaces, with the understanding that these surfaces are the surfaces of wall or panel members which make the prismatic configuration of these two support members 96 and 98.

Reference will now be made to FIG. 10A which is drawn to an enlarged scale and shows the two members 96 and 98 somewhat schematically in a sectional view (or an end view). In FIG. 10A the two members 96 and 98 are placed on top of one another so that the support surface of the support surface solar panel would be at a 15° angle with the horizontal.

For purposes of description the sides and angles of the major triangle 96 and the adjustment triangle 98 will be given designations where a small letter of the alphabet will designate either a side or an angle with a “−1” referring to those of the major triangle 96, and a “−2” referring to the sides or angles of the adjustment triangle 98. These designations are indicated in FIG. 10A which shows the two support members 96 and 98 stacked one on top of the other.

Below are two tables identifying the angles and sides by their designations and also a brief descriptive designation.

Major Triangle 96
Angle a-1 primary major support angle
Angle b-1 secondary major support angle
Side  c-1 primary major support surface
Side  d-1 major solar panel support surface
Side  e-1 secondary major support surface
Angle f-1 third major angle

Adjustment Triangle 98
Angle a-2 primary adjustment support angle
Angle b-2 secondary adjustment support angle
Side  c-2 first primary adjustment support surface
Side  d-2 second primary adjustment support surface
Side  e-2 third adjustment side
Angle f-2 third adjustment angle

The major support member 96 has a primary major support angle a-1 which is the 30° angle (i.e. about ⅓ of a right angle) where the hypotenuse d-1 joins the side c-1 of the major right triangle, and the adjustment support member 98 has its primary adjustment support angle a-2 which is the 15° angle (i.e. about one sixth of a right angle) of the right triangle. With the angle a-2 being about one half of the angle a-1, the significance of these two angles a-1 and a-2 is that in one position, such as shown in FIG. 10A and 10B, to arrive at the slant angle of 15°, the 15° of angle a-2 is subtracted from the 30° of angle a-1 to make the alignment angle of the support surface d-1 of the major support member 96 at the 15° slope. As will be shown later herein, with the position of the adjustment support member 98 being reversed, so that the 15° angle a-2 is added to the 30° angle a-1 the alignment angle of the support surface increases to 45°.

To complete the description of the major support member 96, the hypotenuse surface d-1 is the surface which supports the solar panel in the proper alignment. The longer leg c-1 is a primary major support surface. The short leg of the triangle c-1 is the secondary major support surface and it rests on the underlying surface to provide the support surface at a 600 slant (See FIG. 10E). The angle f-1 is a third major angle, the size of which is dictated by the other angles and side lengths.

The adjustment support member 98 has first and second primary adjustment support surfaces which are designated c-2 and d-2, respectively. Both of these surfaces c-2 and d-2 provide support, and (as indicated before) depending upon which way they are aligned relative to their major support member in the 15° and 45° positions, this will determine whether there will be a larger (45°) or smaller (15°) angle of slant. There is a secondary adjustment support angle b-2 which provides more direct support except in one position that adds stability to the support section 94. The side e-2 is a third adjustment side, and angle f-2 is a third adjustment angle, the size of these being dictated by the size and alignment of the other angles and sides of the adjustment triangle.

To discuss now the manner in which the major support member 96 and the adjustment support member 98 may be used to obtain the various angular orientations for the solar panel section, reference shall be made to FIGS. 10B-10E.

FIG. 10B is the same as FIG. 10A, and it shows the arrangement to obtain the 15° slant from the horizontal. To accomplish this, both the major and adjustment support members 96 and 98 are utilized, and these are stacked one on top of the other so that the primary major support surface c-1 is placed against the first adjustment support surface c-2. The second adjustment support surface d-2 rests on the ground location and the major solar panel support surface d-1 has the desired slant of 15 degrees and supports the solar power section 50. In this configuration, the 15° value of angle a-2 is in effect subtracted from the 30° value of the angle a-1 to arrive at the 15% angle of slope. ;

To obtain the 30° orientation of FIG. 10C, only the major support member 96 is used. The primary major support surface c-2 rests on the ground surface or paved surface, and the major solar panel support surface d-1 has the solar power section 50 positioned thereon. The angle a-1 dictates the 30° tilt angle.

To obtain the 45° angle slope of FIG. 10D, the two support members 96 and 98 are positioned so that the two primary support angles (the primary major support angle a-1 and the primary adjustment support angle a-2) are added to one another to make the 45° angle. It can be seen that this is accomplished by having the two surfaces c-1 and c-2 against one another with the surface d-2 resting on the ground location. However, this arrangement differs from the arrangement of FIG. 10B in that the members 96 and 98 are oriented so that the two angles a-1 and a-2 are next to one another.

To obtain the 60° slant angle of FIG. 10E, the major support member 96 and the adjustment support member 98 are arranged so that the secondary major support surface e-2 of the member 96 rests on the underlying ground or paved surface, and also the third adjustment side e-2 also rests on the ground surface, with the two members 96 and 98 being joined to one another. In this case the secondary major support angle b-1 which is 60° dictates solely the 60° angle of slant of the major solar panel support surface d-1.

To obtain a 750 slope, the same configuration would be used as in FIG. 10E, except that the second adjustment surface d-2 would now become a support surface for the solar power section 50. This would be less likely to occur, since such a steep angle would be used only when the sun is very low on the horizon, and in that position the solar energy would likely be substantially less.

In FIG. 8, the support section 94 is shown in its position of FIG. 10D. The solar panel of the solar power section 50 is positioned so as to be within the major support section 96, with its solar facing surface exposed. Also, the battery section 52, control section 56 are housed within a chamber 100 which is formed by the three walls of the major support member 96. The two support members 96 and 98 may be constructed using buoyant and insulating materials such as thermal plastic foam or with inflatable parts, so that it will float should the unit be accidentally dropped into the pool. A handle 99 is provided on the section 96. Also, the thermally insulating properties of the material used will also protect the battery and electronics from excessive heat, as the unit sits exposed to the sun.

As can be seen in the view of FIG. 9, the two support members 96 and 98 could be connected by Velcro fastener, such as shown at 102. However, other fasteners could be used.

Reference is now made to FIGS. 11-15 to illustrate how the various connections can be made between the panels 28, with respect to the connections by which the water can flow from one panel 28 to the other and also how these can be physically connected in a manner that the panels could be folded over one on top of the other.

FIG. 11 shows the basic construction of the fluid joints. A coupling 104 has one barbed end that snaps into the openings 41 on the sides of the cover sections and another barbed end on which tubing 106 can be threaded.

Inlet and outlet hoses are illustrated in FIG. 12. A standard quick-connect hose coupling 35 is installed on the tubing, so that the pump or the optional outflow tubing can be easily connected and disconnected. On the inlet hose only there may also be a restriction valve to ensure that the water is evenly metered into the water channel grids in the cover sections. The restriction valve 108 additionally serves to limit the water pressure in the cover to protect its integrity.

FIG. 13 shows joining two cover sections, using coupling 104 on both ends of the tubing. An alternative manner of joining panels 28 sections is shown in FIG. 14, where a T shaped tubing 110 is used. As the hydrostatic pressure of the water inside cover sections is low, the inverted leg 112 of the T (typically protruding 2 inches/5 cm upwards) serves as a vent to remove trapped air but does not allow the water to escape when the cover lies flat on the pool surface. However, when the cover is retrieved, tilting the cover sections, these vents allow the water to rapidly drain out of the cover.

To avoid putting too much stress on the fluid joints the cover sections are also mechanically joined using flexible sheets or straps, which may be a continuation of the sheet cover 42 covering the panels 28. FIG. 15 shows an example where two overlapping sheets 42 which are joined using Velcro fasteners 84. Other attachment systems using snaps, hooks, zippers or similar means are equally possible.

Material used for constructing fluid and mechanical joints are selected for their ability to easily bend and/or fold and to tolerate repeated such actions. Elasticity and an intrinsic tendency to return to the original shape are also important. In fluid tubing it is essential to avoid that permanent creases or knees are formed, as these could block the fluid flow. Examples of suitable tubing materials are silicone rubber, EPDM-rubber, Tygon, and Viton which are commercially available. The elastic spring action of fluid and/or mechanical joints is also useful as an aid in making the cover spread out when it is deployed on the water.

Mechanical attachment systems using Velcro or snaps may also be useful to attach various accessories to the cover. One useful accessory is a passive cover section, with insulation but without water channels, as it can be cut to adapt the shape and dimensions of the cover to fit different kinds of pools. Other accessories include anchor points to secure the cover, and/or tracks to guide the deployment and retrieval. Also, such accessories could be a docking station to facilitate launching and retrieval of the cover and brackets to enable the cover to function as a security device to prevent children from falling into the pool.

A common feature of all of the described joint types is that they do not require sophisticated tools or adhesives. This allows the end user to assemble the pool heater system him/herself using the elements supplied and to tailor the installation to fit individual needs. The system can start out small and later be expanded to cover a larger surface or the entire pool. The modular approach also allows cost savings in transportation and warehousing, as only a limit number of standard elements of modest size are required for a wide variety of installation.

In the normal mode of operation of the embodiments of the invention, since the entire operation is automatic the cover section 22 remains on the pool, there is no need for any human intervention. During the days with little sun, no water is circulated through the cover. The insulating properties of the cover minimize heat loss. When solar energy is available, it is harnessed by the automatic circulating of the water so that it can be heated at the surface of the cover.

To illustrate how the cover section 22 could be retrieved from its operating position on the pool and later positioned on the pool, reference is made to FIGS. 16 and 17. These illustrate the handling of the cover section 22.

To remove the cover section 22 from the pool, the power and pumping section 24 is disconnected by means of a quick connect coupling 35. The first panel 28 is pulled up using a strap 31. By pulling further on this strap 31, the following panel 28 is folded over the first. The following panels 2 are pulled up in the same manner, again using the strap 31 provided The cover section 22 can be stored as a stack of folded panels 28, as shown in FIG. 17. In the illustration, the support section 94 is shown placed on top of the stack with the pump section 54 tucked inside its storage compartment.

To deploy the system 20, the removal procedure is reversed. The outlet tube, if used, is reconnected. The uppermost panel 28 is then tilted into the pool 10, followed by subsequent panels 28. The spring action of the elastic fluid and/or mechanical joints between the section 22 aid in the deployment as they force the cover to flatten and float out into the pool 10, as the curved arrows in FIG. 16 attempt to illustrate. Finally the power and pumping section 24 is reconnected to the cover.

A fourth embodiment of the present invention will now be described with reference to FIGS. 18, 19, 20 and 21. Earlier in this text, the first embodiment is described as having the flow paths between the panels 28 being in series, and it was then stated that there could be an alternative flow system where the flow of the water through the panels is done in a manner which could be described as a parallel flow pattern. This is accomplished in this fourth embodiment. In describing this fourth embodiment, components which are the same as, or similar to, components of the earlier embodiment will be given like designations with an “a” suffix distinguishing those of the first embodiment.

To describe this in general terms, in this fourth embodiment, the flow of the water is directed into each panel 28a and is discharged from each panel directly into the pond. In FIG. 18, there is shown in plan view one of the panels 28a which is used in this fourth embodiment.

For purposes of explanation, this panel 28a is shown with only a small part of the top cover sheet 42a, (See the sectional view of FIG. 19), with the understanding that the cover sheet 42a would be bonded to the entire upper surface of the panel 28a.

The panel 28a comprises a base plate 38a, having the flow paths 40a formed as grooves in the plate 38a. As in the first embodiment, these flow paths comprise the laterally extending grooves 88a, and also the edge grooves in which describing this fourth embodiment will be considered as a rear edge groove 90a and forward edge groove 91a. These grooves 88a, 90a and 91a are formed in two grids 89a. The panel 28a has an end to end axis 116 a and a rear to front axis 118a.

The base plate 38a differs from the base plate 38 of the first embodiment in that the in addition to the grooves 88a, 90a and 91a, there are two laterally extending grooves 120a in which is positioned a main central feed conduit 122a at the center of its grid 89. Each conduit 122a has a rear inlet 124a and a forward outlet 126a. The rear 124a of each main feed conduit 122a has a upwardly facing metering opening 128a in the form of a slot, or some other configuration or design. Also, there are two oppositely positioned right angle connecting slots 129a to connect to a pump hose or the like. (See FIG. 20).

At the forward end 126a of the conduit 122a, there is a front end connection, indicated schematically at 130a, and this could connect to any one of the fluid conduit arrangements which are shown in FIGS. 11-14.

At opposite forward locations of each of the two grids 89 on the base plate 38a there are two outlet openings 132a which open from the outer ends of the forward edge groove 91a downwardly directly into the pool. There is positioned in each of these openings 132a outlet flow control tube 134a (See FIG. 21). This tube 134a has a vertically aligned flow through passageway 135a, and the upper inlet edge 136a which extends 180° around the upper end of the tube 134a and is located a short distance below the water level of the flow in the grooves 88a, 90a, and 91a. This 180° edge of the outlet flow control tube 134a is at a level so that the warmer water which collects at the upper surface of the water in the grooves 88a, 90a and 91a will flow over the edge 136a so that the additional water then flows in will be able to be in closer heat exchange relationship with the top sheet 42a of the panel 28a.

At the corner portions of the panel 28a, there are recesses or connecting grooves 138a in which can be placed rubber straps, connecting plates, or other fastening devices so that connection can be made to adjacent panels 28a.

To describe the operation of this fourth embodiment, let it be assumed that this panel 28a is the panel which receives the primary flow of water directly from the pump section 54. This water flows into the rear inlet 124a of each of the main feed conduits 122a. A portion of this water will immediately flow through the upwardly facing metering opening 128a to flow into the rear edge groove 90a. The water flowing into the edge groove 90a flows in opposite directions toward the ends of the groove 90a, and as it does so, the water flows into the rear entry portions of the laterally extending grooves 88a. The water flowing in a forward direction through the grooves 88a enters into the forward edge groove 91a and then flows laterally toward the outlet openings 132a to flow over the 180° edge 136a of the flow control tube 134a and downwardly through the tube 134a into the pool.

At the same time, the main stream of water from the pump section 54 continues its flow through the main feed conduit 122a through the front connection 130a to the rear inlet end 124a of the adjacent panel 28a. Then the same flow pattern occurs in the next adjacent panel 28a, with the water flowing into the rear edge groove 90a, through the grooves 88a and into the forward edge groove 91a. This flow pattern continues, until that water flows into the panel 28a which is the end panel in the furthest downstream direction, and in that panel 28a, the forward end of the main central feed conduit 122a is plugged.

Thus, in this flow pattern, the central feed conduit 122a has a sufficiently large cross section and also has a low friction inner surface so that there is a relatively small back pressure along the length of the main central feed conduit 122a. Further, the metering openings 128a can be sized so that the amounts of flow through each of the panels 28a is substantially equal.

Claims

1. A self regulating heating system to heat water in a pool, having a pool location: a) cover section constructed and arranged to be positioned at an upper surface of said water and to extend over at least a portion of said surface of the water; b) said cover section having a solar energy absorbing surface region and having flow paths with inlet and outlet portions for water to pass through said cover section in a manner to be heated by energy absorbed by said solar energy absorbing surface region; c) a power and pumping section to circulate water from said pool through said cover section to be heated and back to said pool; d) said power and pumping section comprising a pump section to pump the water, a battery section to supply power to the pump section, a solar power section also exposed to solar energy to convert said solar energy for the power and pumping section to enable the pump section to operate, and a control section; e) said control section being operatively connected at least to said pump section to cause the pump section to operate in cycles to first circulate the water through the cover section for a pumping period of the cycle and turn off the pump section for a non-pumping period of the cycle, said control section being arranged to be responsive to a value related to intensity of the solar energy directed to the cover section and the power and pumping section, so that during periods of greater intensity of the solar energy the non-pumping periods of the pump section are of lesser duration, and during periods of lesser intensity of the solar energy, the non-pumping periods are of greater duration; whereby the system is self regulated to take advantage of periods of greater solar intensity when water in the cover section is heated more rapidly, by having the pump section operate in more frequent cycles to re-circulate more heated water, and during periods of lesser solar intensity the cycles are of less frequency.

2. The system as recited in claim 1, wherein during the non-pumping period of the cycle, electrical energy from the solar power section charges the battery up to a higher level and said control section responds at least in part to a situation where the voltage level of the battery section rises to a higher level to start the pumping period of the cycle.

3. The system as recited in claim 2, wherein said system is characterized in that during the pumping period of the cycle the power consumed by the pump section causes the output voltage of the battery section to drop, said control section being arranged to respond to a voltage drop in the battery section to end the pumping period of the cycle.

4. The system as recited in claim 1, wherein said system is characterized in that during the pumping period of the cycle the power consumed by the pump section causes the output voltage of the battery section to drop, said control section being arranged to respond to a voltage drop in the battery section to end the pumping period of the cycle.

5. The system as recited in claim 1, wherein the pumping period of at least some of the cycles is terminated in response to the length of time from the starting of the pumping cycle.

6. The system as recited in claim 5, where the length of time from the starting of the pumping cycle would at least some of the time be greater at a higher level of solar intensity and lower for a lower level of solar intensity.

7. The system as recited in claim 1, wherein said solar power section has a power connection to said battery and to said motor, so that during the pumping period of the cycle, the solar power section is transmitting power to said pump section, and said battery section is also transmitting power to said pump section, with the pump section drawing sufficient power so that the solar power section and the battery section supply power to the pump section, but with the output voltage from the battery section becoming lower during the pumping period of the cycle, said control section having a monitoring function to be responsive to the level of the output voltage of the battery section to cause the pump section to start pumping to initiate the pumping period when the output voltage of the battery has reached a predetermined higher level, and to cause the pumping period of the cycle to cease when the output voltage of the battery has reached a predetermined lower level and/or after the predetermined length of time from a starting of the pumping cycle.

8. The system as recited in claim 1, wherein said solar power section has a power connection to said battery section and to said pump section, said control unit having a monitoring connection to a voltage output of said battery section and to a voltage output of said solar power section, said control section being arranged to monitor the voltage of the solar power section relative to the voltage output of said battery section to enable said battery to be charged to a predetermined higher level prior to starting the pump section for the pumping period of the cycle until the battery section has been charged to a level to supply sufficient power to start the pump section operating during the beginning of the pumping period.

9. The system as recited in claim 8, where the length of time from the starting of the pumping cycle would at least some of the time be greater at a higher level of solar intensity and lower for a lower level of solar intensity.

10. The system as recited in claim 1, wherein said cover section comprises a plurality of panels which are arranged to be positioned in side by side relationship on the water surface, each of said panels being provided with flow paths, and with adjacent panels having fluid connections therebetween, said system being arranged so that the power and pumping section circulates water from the pool into at least one of said panels and through fluid connections to other panels, with the outlet being at one of said other panels, said panels being interconnected with one another so that said panels can be folded over relative to one another to be stacked one on top of the other.

11. The system as recited in claim 1, wherein adjacent pairs of panels are arranged with connecting straps which extend across the adjacent pair of panels, said connecting strips being arranged so that pulling on the strap lifts opposite sides of the panels upwardly and toward one another so that the panels moved to a position being adjacent to one another and are able to be placed in stacked relationship.

12. The system as recited in claim 1, wherein said cover section comprises: a) a plurality of panels which are arranged to be positioned on the water surface, each of said panels comprising forward and rear side edges, and end edges, said panels being positioned in side by side relationship with pairs of adjacent panels having front and side panels edges of adjacent two panels in side by side relationship, each panel having a front to rear axis and an end to end axis perpendicular to the front to rear axis; b) each panel comprising a main feed conduit generally aligned with said forward to rear axis of the panel and having a rear inlet portion and a forward outlet portion; c) each panel having a rear flow path and a forward flow path, both of which are generally aligned with the end to end axis, and further having a plurality of lateral flow paths spaced from one another and extending from the rear flow path to the forward flow path; d) said rear portion of said main feed conduit having a metering opening to deliver water into said rear flow path at a first upstream end location relative to said end to end axis to flow along the length of said rear flow path, with the water in the rear flow path flowing forwardly through said lateral flow paths into the forward flow path; e) each panel having a forward water outlet opening which is spaced a substantial distance from the first end to end location relative to said end to end axis, to discharge from the panel the water which has flowed through the lateral flow paths and the forward flow path; f) each panel that has an adjacent forward panel having a fluid connection of the main feed conduit from its forward outlet portion to the rear inlet portion of the adjacent forward panel to direct water to the main feed conduit for distribution through the flow paths of the adjacent forward panel and discharge the water from the adjacent panel.

13. The system as recited in claim 1, wherein there is a support section for said solar power section, comprising: a) a major support member comprising; i. a major solar panel support surface to support said solar power section in a solar energy receiving position of greater and lesser slant angles; ii. a primary major support surface; iii. said major solar panel support surface and said primary major support surface slanting toward one another at a primary major support angle that is approximately one third of a right angle; b) an adjustment support member comprising: i. a first primary adjustment support surface; ii. a second primary adjustment support surface; iii. said first primary adjustment support surface and said secondary primary adjustment support surface slanting toward one another at a primary adjustment support angle which about one half of the primary major support angle; c) said major support member being arranged to be positioned on said adjustment support member in a first stacked configuration where the primary adjustment support angle and primary major support angle are adjacent to one another to position the major solar panel support surface at a greater slant angle substantially equal to the sum of the primary major support angle and the primary adjustment support angle and in a second stacked configuration the primary adjustment support angle and primary major support angle are positioned at opposite sides of the stacked configuration to position the major solar panel support surface at a lesser slant angle substantially equal to the difference of the primary major support angle and the primary adjustment support angle and in a second stacked configuration.

14. The system as recited in claim 13, wherein said major triangle also comprises a secondary major support surface which makes a third angle with said primary major support surface, and said major support member may be positioned with said secondary major support surface supporting the major support section with the slant angle of the primary major support surface being greater than the sum of the primary major support angle and the primary adjustment support angle.

15. A self regulating method of heating the water in a pool, having a pool location, said method comprising: a) positioning a cover section at an upper surface of the water in the pool to extend over at least a portion of said surface of the water; b) providing said cover section with a solar energy absorbing surface region and flow paths with inlet and outlet portions for water to pass through said cover section in a manner to be heated by energy absorbed by said solar energy absorbing surface region; c) operating a power and pumping section to circulate water from said pool through said cover section to be heated and back to said pool with said power and pumping section comprising a pump section to pump the water, a battery section to supply power to the pump section, a solar power section also exposed to solar energy to convert said solar energy for the power and pumping section to enable the pump to operate, and a control section; d) providing control inputs at least to said pump section to cause the pump section to operate in cycles to first circulate the water through the cover section for a pumping period of the cycle and turn off the pump section for a non-pumping period of the cycle, relating said control inputs to a value related to intensity of the solar energy directed to the cover section and the power and pumping section, so that during periods of greater intensity of the solar energy the non-pumping periods of the pump section are of lesser duration, and during periods of lesser intensity of the solar energy, the non-pumping periods are of greater duration; whereby the system is self regulated to take advantage of periods of greater solar intensity when water in the cover section is heated more rapidly, by having the pump section operate in more frequent cycles to re-circulate more heated water, and during periods of lesser solar intensity the cycles are of less frequency.

16. The method as recited in claim 15, wherein during the non-pumping period of the cycle, electrical energy from the solar power section charges the battery up to a higher level and said control section responds at least in part to a situation where the voltage level of the battery section rises to a higher level to start the pumping period of the cycle.

17. The method as recited in claim 15, wherein said solar power section has a power connection to said battery and to said motor, so that during the pumping period of the cycle, the solar power section is transmitting power to said pump section, and said battery section is also transmitting power to said pump section, with the pump section drawing sufficient power so that the solar power section and the battery section supply power to the pump section, but with the output voltage from the battery section becoming lower during the pumping period of the cycle, said control section having a monitoring function to be responsive to the level of the output voltage of the battery section to cause the pump section to start pumping to initiate the pumping period when the output voltage of the battery has reached a predetermined higher level, and to cause the pumping period of the cycle to cease when the output voltage of the battery has reached a predetermined lower level and/or after predetermined the length of time from the starting of the pumping cycle.

18. The method as recited in claim 15, wherein said solar power section has a power connection to said battery section and to said pump section, said control unit having a monitoring connection to a voltage output of said battery section and to a voltage output of said solar power section, said control section being arranged to monitor the voltage of the solar power section relative to the voltage output of said battery section to enable said battery to be charged to a predetermined higher level prior to starting the pump section for the pumping period of the cycle until the battery section has been charged to a level to supply sufficient power to start the pump section operating during the beginning of the pumping period.

19. The method as recited in claim 18, where the length of time from the starting of the pumping cycle would at least some of the time be greater at a higher level of solar intensity and lower for a lower level of solar intensity.

20. The method as recited in claim 15, comprising providing said cover section as a plurality of panels, arranging the panels in side by side relationship on the water surface, each of said panels being provided with flow paths, and with adjacent panels having fluid connections therebetween, said method further comprising operating the power and pumping section to circulate water from the pool into at least one of said panels and through fluid connections to other panels, with the outlet being at one of said other panels, and/or at some of the panels, and interconnecting said panels being interconnected with one another so that said panels can be folded over relative to one another to be stacked one on top of the other.