WO1993015317A1

WO1993015317A1 - Improvements in or relating to pumping systems

Info

Publication number: WO1993015317A1
Application number: PCT/GB1993/000148
Authority: WO
Inventors: Kenneth Gray; John Anthony Lucey
Original assignee: Kenneth Gray
Priority date: 1992-01-24
Filing date: 1993-01-22
Publication date: 1993-08-05
Also published as: GB9201580D0; AU3362993A

Abstract

A pumping system (50) for pumping water from an underground source (13) to a collecting tank (16) disposed above ground level comprises a solar panel (1) and first and second pressure vessels (4, 8) respectively. Solar energy, collected by the panel (1), causes expansion of a working fluid contained therein, resulting in inflation of a bladder (5) disposed within (4) and a consequential reduction in the volume of compartment (6). This causes displacement fluid to be discharged from the compartment (6) and into the interior of a bladder (9) disposed within (8) connected thereto. The bladder (9) is thus caused to inflate, whereby the volume of the compartment (10) is reduced, so that water is expelled from the compartment (10), along duct (14), through non-return valve (15), and into the tank (16). When a predetermined amount of water has been discharged to the tank (16), it is automatically discharged therefrom, for subsequent irrigation purposes, cooling the solar panel (1) en route. This cooling causes contraction (or condensation) of the working fluid contained therein, so that the bladder (5) contracts, whereby displacement fluid is transferred from the bladder (9) into the compartment (6). This results in water being drawn from the underground source (13), into the duct (11) and from thence into the compartment (9), so as to replace the water discharged therefrom. Meanwhile, the non-return valve (15) prevents backflow into the compartment (9) by way of duct (14). When water used to cool the solar panel (1) has drained away, the panel reheats, and the pumping cycle is repeated.

Description

IMPROVEMENTS IN OR RELATING TO PUMPING SYSTEMS

BACKGROUND TO THE INVENTION

This invention relates to pumping systems and is primarily, but not exclusively, concerned with solar powered pumping systems.

Such pumping systems have particular application to the pumping of irrigating water from below ground level.

The most arid regions of the earth tend to have an abundance of solar energy as well as a substantial need to pump water from underground sources or depleted rivers. In such regions electrical power is seldom available; petrol and diesel fuels tend to be too expensive; machine maintenance operators scarce, and spare parts difficult to obtain.

SUMMARIES OF THE INVENTION

According to one aspect of the present invention, a pumping system comprises a solar energy collection means employing a working fluid which expands when raised in temperature and which contracts when lowered in temperature, a pumping chamber of variable volume having a fluid inlet and a fluid outlet, and displacer means for utilising expansion and contraction of the working fluid to vary the volume of the pumping chamber in a cyclic manner whereby fluid is passed through the pumping chamber by way of said inlet and said outlet.

According to another aspect of the present invention, a pumping system according to the preceding paragraph is operable as a master pumping system and is combined with a slave pumping system operable, whereby the pumped output of the water pumping system is used to promote operation of the slave pumping system. According to yet a further aspect of the present invention, a pumping system comprises at least two bellows, namely a pumping bellows having an inlet and an outlet, and an actuating bellows operable in a cyclic manner by pressurised fluid so as to vary the internal volume of the pumping bellows also in a cyclic manner, whereby pumping takes place.

According to yet another aspect of the present invention, a pumping system comprises cylinder means, a pair of axially-spaced and inter¬ connected pistons slidably located by the cylinder means, structural means separating the pistons from each other so as to define a pair of piston chambers with said cylinder means, and incorporating control valve means operable by reciprocal movement of the pistons to allow fluid flow into and out of said piston chambers.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of the present invention will now be described by way of example only, with reference to the accompanying semi- diagrammatic drawings, wherein:

Figure 1 is a side view of a pumping system according to one embodiment;

Figure 2 is a side view which illustrates a modification of the pumping system of Figure 1;

Figure 3 s a side view which llustrates a second embodiment;

Figure 4 is a plan view thereof;

Figure 5 is a side view which illustrates a third embodiment, and

Figure 6 is a fragmentary side view which illustrates a modification of the Figure 3 embodiment. DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

Figure 1 shows a pumping system 50 for use in pumping water from an underground source 13 to a collecting tank 16 disposed above ground level .

The pumping system 50 comprises a solar energy collection panel 1 and first and second pressure vessels 4, 8 respectively.

The vessels 4, 8 are disposed at substantially the same level.

The solar panel 1, which may be provided with a glazed cover in order to increase heat gain, has internal flow channels connected, by way of a duct 2, to the interior of a first inflatable chamber comprising a bladder 5, disposed within the first vessel 3. The internal channels of the solar panel 1, the duct 2, and the bladder 5 are filled with a working fluid which expands when raised in temperature and which contracts when lowered in temperature. The working fluid may comprise a hydrocarbon compound such as hexane, or a CFC refrigerant.

The bladder 5 defines a compartment 6 with the surrounding wall of the vessel 4. The compartment 6 is connected, by way of a transfer duct 7, to the interior of a second inflatable chamber, comprising a bladder 9, which is disposed within the second vessel 8, and defines a pumping compartment 10 therewith. The bladder 9 serves as displacer means. The vessel 8 serves as a pumping chamber and has a fluid inlet and a fluid outlet.

The compartment 10 is connected by way of a draw-off duct 11, and a non-return valve 12, to the underground water source 13.

The compartment 10 is also connected, by way of a discharge duct 14 and non-return valve 15 disposed therein, to the interior of the water collecting tank 16. Water level in the collecting tank 16 is controlled by automatic means, llustrated in Figure 1 by a water level initiated syphon 17. When a predetermined water level is reached, water is discharged from the tank 16, downwardly into a tank 18, disposed substantially below the tank 16. From the tank 18, the water is caused to discharge, in spray form, over the exterior of the solar panel 1, to be collected, by way of a duct 19, for subsequent irrigation or other use.

The interiors of the compartment 6, duct 7, and bladder 9 are filled with a substantially non-compressible displacement fluid, such as. oil. The displacement fluid has low heat transfer properties so as to substantially reduce transfer of heat from the working fluid within the vessel 4, and so limit condensation of the working fluid in compartment 6.

The interiors of the duct 11, compartment 10 and duct 14 are filled with water.

In operation, solar energy, collected by the panel 1, causes expansion of the working fluid contained therein. This expansion causes expansion or inflation of the bladder 5 and a consequential reduction in the volume of compartment 6.

This reduction in volume causes displacement fluid to be discharged from the compartment 6 and into the interior of the bladder 9 connected thereto.

The bladder 9 is thus caused to inflate, whereby the volume of the compartment 10 is reduced. This results in water being expelled from the compartment 10, along duct 14, through non-return valve 15, and into the collecting tank 16. Backflow of water through the duct 11 is prevented by the non-return valve 12. When a predetermined amount of water has been discharged to the collecting tank 16, it is automatically discharged therefrom, for subsequent irrigation purposes, cooling the solar panel 1 en route.

Cooling the solar panel 1 causes contraction (or condensation) of the working fluid contained therein. This causes the bladder 5 to contract, whereby displacement fluid is transferred from the bladder 9 into the compartment 6. This results in water being drawn from the underground source 13, into the duct 11 and from thence into the compartment 9, so as to replace the water discharged therefrom. Meanwhile, the non-return valve 15 prevents backflow into the compartment 9 by way of duct 14.

When water used to cool the solar panel 1 has drained away, the panel reheats, and the pumping cycle is repeated.

The embodiment of Figure 1 is concerned with a pumping sys^*. -..; wherein water is lifted from a source by the application of suet¹ ""^> to the water being pumped or reduction in pressure of t ^• displacement fluid.

Figure 2 illustrates a modification wherein a positive pressure pumping system 60 or pressure is used to draw water from deeper underground sources.

The system 60 may be disposed above the water level of the deep source 61, as shown in Figure 2, or it may be immersed in the source 61.

The pumping system 60 comprises three water-filled axially extendable bellows 22, 23, 24 mounted in a restraining frame 20. The upper ends of bellows 23, 24 and the lower end of bellows 22, are fixed to the frame 20. The opposite or free ends of the bellows 23, 24 are connected, by way of a plate 21, to the free end of bellows 22. The pumping system 60 may be viewed as a slave pumping system and the pumping system 1 may now be viewed as a master pumping system which controls the system 60 so as to promote operation thereof.

The interior of bellows 23 has an inlet, connected by way of a draw-off duct 62, and a non-return valve 25 mounted therein, to the water source 6. The interior of this bellows also has an outlet, connected by way of branch duct 63, a non-return valve 29 mounted therein, and a main or riser duct 26, to the interior of a header tank 27.

The interior of the bellows 24 is connected, by way of a branch duct 64, to the main duct 26 and thus to the interior of the header tank 27. The header tank 27 has an elevated outlet 28 which discharges to the collection tank 16 of Figure 1.

The interior of the bellows 22 is connected to a pressurised water supply source, in this example, the outlet end of the duct 14 of Figure 1.

Bellows 22 is an actuating bellows; bellows 23 is a water delivery bellows; and bellows 24 a water pressurising bellows.

In operation, pressurised water from the duct 14 flows into the interior of the actuating bellows 22, causing the bellows 22 to expand and the bellows 23, 24 connected thereto to contract. Contraction of the bellows 23, 24 causes water to be expelled from the interiors thereof, first into the duct 26 and from thence to the header tank 27.

When the water level in the header tank 27 reaches the outlet 28 thereof, the water flows into the collecting tank 16 of Figure 1, to be employed as previously described, whereby the solar panel 1 is cooled. This causes pressure in the duct 14 (Figure 2) to fall, whereupon the bellows 22 contracts lowering the plate 21 and extending the bellows 23, 24.

The result is that water is drawn from the source 61 into the bellows 23, non-return valve 29 closing to prevent backflow of water into the bellows 23. However, backflow is allowed to take place in the case of bellows 24, whereby a downwardly acting force is applied to the plate 21, derived from the head of water in the duct 26.

This force is transferred to the bellows 22, providing a similar pressure-head therein, which supports the column of water in the delivery duct 14. Thus water can flow up the duct 14 without being dependent on the barometric head.

When cooling of the solar panel 2 is complete, the plate 21 will be at its lowest position, and the water level in the header tank 27 will be at its minimum.

The operating cycle is then repeated as the working fluid reheats. At the end of the heating process, a volume of water equal to the displacement of the delivery bellows 23, will have entered the header tank 27, whilst the displacement volume of the pressurising bellows 24 will have recharged the header tank 27.

In Figure 2, the delivery bellows 23 and the pressurising bellows 24 are shown side by side for clarity. An alternative embodiment could have these bellows arranged concentrically, thus making the deep pump unit 60 more compact and ensuring that all the forces on the plate 21 act along the same line.

Alternative embodiments are possible wherein the pressurising bellows 24 are dispensed with, and the required downward force upon the plate 21 is derived from an addition of weight to the plate, or is derived from the force of a mechanical spring bearing upon it. An alternative embodiment could use single or double-acting pistons within cylinders instead of some or all of the bellows and the plate could then be replaced by a linking piston rod.

Figures 3 and 4 illustrate a water pumping system 70 which employs a pair of pistons disposed in tandem.

The pumping system 70 comprises a solar energy collection panel 71, (which corresponds to panel 1 of Figure 1).

Pressure vessels 78, 79 house bladders (not shown) and correspond to vessels 4, 8 of Figure 1. A collecting tank 80 corresponds to collecting tank 18 of Figure 1. The pressure vessel 78 is pivotably mounted on a stationary base 72 so as to be able to tilt about a substantially horizontal axis 73. The axis 73 is disposed adjacent one edge of the solar panel 71. The opposite edge of the panel 71 supports a valve member 74 which co-operates with a valve seat 75 disposed in a tray 76 having an outlet duct 77 corresponding to outlet duct 19 of Figure 1. A counterweight 81 biasses the valve 74/75 towards a closed position. Pressure vessel 79 is mounted on the base 72 in a fixed manner.

The ^"pressur ser" unit 85 of the pumping system 70 comprises cylinder means in the form of a substantially vertical cylinder 105 housing upper and lower pistons 87, 88 disposed in tandem and interconnected by a piston rod 89. A gland 95, through which the piston rod 89 passes, divides the cylinder 86 into upper and lower piston chambers 96, 97.

Piston 87 is a double-acting piston. Piston 88 is a single-acting piston, the lower end of the cylinder 86 not being closed.

A water head balancing duct 98 connects the collecting tank 80 with the upper end of the piston chamber 96, as well as the upper end of the p ston chamber 97. The duct 98 incorporates a non-return valve 99. That part of the duct 98 below the non-return valve 99 serves as a water lift duct.

A pressurising duct 100 connects the collecting tank 80 with the lower end of the piston chamber 96. A water suction duct 105 connects the upper end of the piston chamber 97 with a below ground water source 106. A non-return valve 107 is disposed in the lower end of the duct 105.

In operation, as solar energy heats the working fluid within the solar panel 71, the fluid expands so as to be forced out of the panel and into the bladder disposed inside the pressure vessel 78.

As the bladder expands, the displacement fluid (oil) surrounding it is displaced, thus reducing the overall weight of the pressure vessel 78. The counterweight 85 can then come into operation, closing the valve 74/75.

The displaced oil is transferred into the bladder disposed within the pressure vessel 79, by way of a transfer duct 108, so as to cause water surrounding that bladder to be forced down through the duct 100 and into the piston chamber 96. This action causes the piston 87 to lift, drawing the interconnected piston 88 upwardly with it. The combined movement of the pistons 87, 88 causes water to flow upwardly through duct 98 and into the collecting tank 80, backflow being prevented by the non-return valve 99.

When the collecting tank 80 is full, water overflows into a cistern 110 provided with an automatic water syphon 111. When the cistern 110 is full, the syphon 111 causes water to flow into the tray 76 so as to cool the solar panel 71 and the working fluid contained therein. As the valve 74/75 is closed, water is retained within the tray. Cooling of the solar panel 71 results in contraction of the bladder disposed in the pressure vessel 78 and thus transfer of displacement fluid from the bladder in the pressure vessel 79 to the interior of the pressure vessel 78.

This causes water to be drawn from the duct 100 and into the pressure vessel 79, allowing pistons 87, 88 to descend, assisted by the balancing head of water in the duct 98.

Downward movement of the pistons 87, 88 causes water to be drawn up from the source 106, by way of the duct 105, so as to refill that part of the piston chamber 97 which is above the lower piston 88. Simultaneously, water is displaced from that part of the piston chamber 96 which is above the upper piston 87, into the pressurising duct 100, and from thence into the pressure vessel 79.

As the pressure vessel 78 gains weight provided by the return of displacement fluid (oil), and after water immersion and cooling of the panel 71, this increase in weight overcomes the effect of the counterweight 81, causing the valve 74/75 to open and discharge water through the duct 76.

The cycle is then repeated.

Figure 5 illustrates a water pumping system 120 -which makes use of a pump 121 disposed at ground level in order to lift water from an underground source 122. The pump 121 may comprise a manually operated pump, or one driven by a power source.

The pump 121 can be viewed as a master pump unit, and the remainder of the system a slave pump unit.

The pumping system 120, which is disposed in a bore hole, comprises cylinder means in the form of a substantially vertically disposed cylinder 123 which slidably locates upper and lower double-acting pistons 124, 125, disposed in tandem and interconnected by a piston rod 126.

Structural means in the form of a gland seal 127 divides the cylinder 123 into upper and lower piston chambers 130 and 131. The gland seal 127, through which passes the piston rod 126, comprises a block defining water flow passageways 132, 133, 134, 135. Passageways 132, 133 allow water flow to and from the upper piston chamber 130 and passageways 134, 135 allow water flow to and from the lower piston chamber 131. Double-headed poppet valves 136, 137 operable by spring-loaded rocker levers 138, 139 control flow through the passageways. The pistons 124, 125, carry pegs 140, 141 which are used to actuate the rocker levers 138, 139. The valves 136, 137 and associated components comprise valve means operable by reciprocal movement of the pistons so as to allow fluid flow into and out of the piston chambers 130, 131.

A water collecting tank 150 is disposed above ground level 151. Ducts 152, 153 and 154 connect the lower end of the piston chamber 131 with the tank 151. Duct 153 houses a non-return valve 155. The lower end of duct 153 has an extension 156 which extends from the water source 122, and which is provided with a non-return valve 157.

The upper end of the piston chamber 130 is connected, by way of ducts 160, 161 and duct 154, to the tank 151. Duct 161 houses a non-return valve 162. The lower end of the duct 161 extends into the water source 122 and is provided with a non-return valve 163.

The passageways 133, 135 are connected to a duct 164 which is connected in turn to the outlet of the pump 121. The passageways 132, 136 are connected to ducts 153 and 161 respectively. A duct 165 provided with a non-return valve 166 interconnects the ducts 154, 164. The valve 166 does not allow backflow from duct 164 to duct 154. The pump 121 draws water from the tank 150 by way of a short length duct 167.

Some or all of the ducts mentioned above in connection with Figure 5 may comprise flexible hoses.

In operation, pressurised water from the discharge of pump 121 enters the above-piston part of the piston chamber 131 by way of the duct 164 and passageway 135, forcing the piston 125 downwardly. This action causes water below the piston to be discharged to the tank 150 by way of duct 153, non-return valve 155, and duct 154.

At the same time, the upper piston 124 is pulled downwardly, (being connected to lower piston 125 by the piston rod 138), causing water to be discharged to the tank 150, again by way of ducts 153 and 154.

Simultaneously, this downward displacement of the pistons 124, 125 cause water to be sucked up from the source 122, by way of the non-return valve 163, and ducts 160, 161 into the above-piston part of the piston chamber 130.

When the upper piston 124 is almost at the end of its downward stroke, peg 141 contacts the rocker lever 138 whereby it pivots, against its spring loading, to allow flow through passageway 133 and to first restrict, and then prevent, flow through the passageway 132. At the same time, depression of poppet valve 136 opens passageway 134 and, by p votable movement of the rocker lever 139, passageway 135 is closed-off.

Water from duct 164 can now enter the lower end of the piston chamber 130, forcing piston 124 (and interconnected piston 125) upwardly. In turn, water is forced out of the cylinder 123 by the pistons 124 and 125, into the ducts 160, 161, past non-return valves 162, 155, and into the tank 150, by way of the duct 154. At the same time water is sucked up past non-return valve 157 and through the ducts 156, 152, into the lower part of the piston chamber 131 and into the upper part of chamber 131, by way of the passageway 132.

As upward movement of the pistons 124, 125 takes place, the peg 141 on the piston 125 actuates the spring-loaded rocker lever 139, so as to change the positions of the poppet valves 136, 137 and thereby switch the passageways 132 etc from open to closed conditions, and vice versa.

The duct 165 and non-return valve 166 are not required when pump 121 is of the continuously-operating type, only when a pump is used which operates with alternating suction and pressure periods.

Figure 6 illustrates a modification of the Figure 3 pumping system. With reference to Figure 6, which shows a master pumping system 200, the upper end of the water head balancing duct 98 is connected to a water head tank 201 wherein pumped water is collected.

The upper end of the two-way flow water pressurising duct 100 is connected to an above-ground disposed manual pump 202 comprising a piston 203, slidably located within a cylinder 204, the piston being displaced by use of a 'T' handle 205.

In a non- llustrated modification, ducts 132, 134 may be disconnected from ducts 153, 161. Instead, the ducts 132, 134 may be interconnected, and then led, by another duct, to a point downstream of non-return valve 166. This enables water to flow from the interconnected ducts 134, 136 to the pump 121 by way of the non-return valve 166.

This arrangement ensures that water in the ducts 132, 134 is at substantially the same pressure. Furthermore, that water circulating in the pumping system and through the poppet valves 136, 137 is clean and substantially free from dirt or sand sucked up from the underground source 122.

As water in the interconnected ducts 132, 134 is at substantially the same pressure, sealing of the poppet valves stems does not present any problem.

It may be possible to employ an emulsion comprising a mixture of oil and water as a hydraulic fluid in any of the above-described arrangements.

The slave pumping systems of Figures 2 to 6 may be used independently of the master pumping systems described and illustrated herein.

Claims

1. A pumping system (50) comprising a solar energy collection means (1) employing a working fluid which expands when raised in temperature and which contracts when lowered in temperature, characterised in that a pumping chamber (8) of variable volume is provided having a fluid inlet (11) and a fluid outlet (14), and displacer means (9) for utilising expansion and contraction of the working fluid to vary the volume of the pumping chamber (8) in a cyclic manner whereby fluid is passed through the pumping chamber (8) by way of said inlet (11) and said outlet (14).

2. A pumping system as claimed in claim 1, wherein the displacer means (9) comprises inflatable bladder means (5) containing a substantially incompressible fluid.

3. A pumping system as claimed in claim 1 or 2, for pumping water, provided with cooling means (16, 17) operable by the pumped water output of the system to reduce the temperature of the working fluid in a cyclic manner.

4. A pumping system as claimed in claim 3, wherein the cooling means (16, 17, 18) comprises a water storage receptacle (16) for receiving the pumped water output, and automatic valve means (17) for releasing at least some of the stored water when the level of water in the receptacle (16) reaches a predetermined level.

5. A pumping system as claimed in any one of claims 1 to 4, operable as a master pumping system, in combination with a slave pumping system (60) operable whereby the pumped output of the master pumping system is used to promote operation of the slave pumping system.

6. The combination of claim 5, wherein the slave pumping system (60) comprises at least one subsidiary pumping chamber (23) of variable volume, and activating means (22) operable by said pumped output so as to vary the volume of said pumping chamber so as to promote the flow of fluid therethrough.

7. The combination of claim 6, wherein the subsidiary pumping chamber (23) and the actuating means (22) comprise bellows.

8. A pumping system comprising at least two bellows, namely a pumping bellows (23) having an inlet (62) and an outlet (63), and an actuating bellow (22) operable in a cyclic manner by pressurised fluid, so as to vary the internal volume of the pumping bellows also in a cycl c manner, whereby pumping takes place.

9. The combination of claim 5, wherein the slave pumping system (70) comprises a pair of interconnected pistons (87, 88), slidably located by cylinder wall means (105), wherein one piston (87) is operable in a cyclic manner by said pumped output, and the other piston (88) is operable to pump fluid.

10. A pumping system (120) comprising a cylinder (123), a pair of axially-spaced and interconnected pistons (124, 125) slidably located by the cylinder (123), structural means (127) separating the pistons from each other so as to define a pair of piston chambers (130, 131), and incorporating control valve means (136, 137) operable by reciprocal movement of the pistons to allow fluid flow into and out of said piston chambers.

11. A pumping system as claimed in claim 10, wherein said control valve means comprises valve members (136, 137) movable between open and closed positions by actuators (138, 139) operable by contact with said pistons.

12. A pumping system as claimed in claim 11, wherein said valve members comprise double-ended poppet valves (136, 137).

13. A pumping system as claimed in claim 11 or 12, wherein said actuators comprise rocker levers (136, 137).

14. A combination pumping system as claimed in claim 5, wherein the master pumping system of the combination comprises a manually- operated pump.

15. A pumping system as claimed in any one of claims 1 to 4, 8, 10 or 11 to 13, or the combination claimed in any one of claims 5 to 7, 9 and 14, disposed and arranged so as to pump water from beneath the surface of the ground.

16. A pumping system substantially as hereinbefore described, with reference to Figure 1 of the accompanying drawings.

17. A pumping system substantially as hereinbefore described, with reference to Figure 2 of the accompanying drawings.

18. A pumping system substantially as hereinbefore described, with reference to Figures 3 and 4 of the accompanying drawings.

19. A pumping system substantially as hereinbefore described, with reference to Figure 5 of the accompanying drawings.

20. A pumping system substantially as hereinbefore described, with reference to Figure 3 of the accompanying drawings, modified substantially as hereinbefore described with reference to Figure 6 of said drawings.