WO2016151197A1

WO2016151197A1 - Solar powered fluid pump and related system

Info

Publication number: WO2016151197A1
Application number: PCT/FI2016/050180
Authority: WO
Inventors: Vilho Hinkkanen
Original assignee: Vilho Hinkkanen
Priority date: 2015-03-23
Filing date: 2016-03-22
Publication date: 2016-09-29
Also published as: TWI615549B; FI127533B; TW201636509A; FI20155198A

Abstract

The invention concerns a solar powered fluid pump (10) having a pressure vessel (12) for receiving solar radiation. The pressure vessel (12) is divided by a diaphragm (13) into a first chamber and a second chamber inside the pressure vessel (12), wherein a change in pressure in one chamber moves the diaphragm (13) and changes the volume of both chambers. The fluid pump (10) comprises shading means for achieving recurring pumping action. The shading means comprise shade covers (14) and an actuator for moving the shade covers (14) between positions where the pressure vessel (12) is exposed to the sun and shaded from the sun.

Description

SOLAR POWERED FLUID PUMP AND RELATED SYSTEM

FIELD OF THE INVENTION

The present invention relates to pumps, and particularly to solar powered fluid pumps. The invention also relates to a system using said fluid pump.

BACKGROUND OF THE INVENTION

Solar powered fluid pumps have been developed over the years but typical solutions are designed for a single purpose and are not suitable for any other tasks. The prior art solutions also require manual work for starting and/or running the fluid pump so those can not be used in a fully automated systems.

French patent publication FR2453992 discloses a water pump system based on a pressure vessel having a flexible diaphragm. Solar radiation heats up the pressure vessel causing a rising pressure in the pressure vessel which pushes water out from another pressure vessel located in the well. The pumped water rinses the heated pressure vessel and cools it down in order to lower the pressure and to cause a recurring pumping action.

One of the disadvantages associated with the above arrangement is that the pumping action needs manual cooling of the pressure vessel until water flows from the well to the surface. Otherwise the pressure vessel wouldn't cool down and the recurring pumping action would not start. Another disadvantage of the system is that it can only be used for pumping liquids which then can be used to rinse the pressure vessel which could contaminate the pumped water. The cooling system also makes further pressurized distribution of the pumped water difficult with the disclosed system.

BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention is thus to provide an apparatus and a system comprising the apparatus so as to overcome the above problems. The objects of the invention are achieved by an apparatus and an arrangement which are characterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

The invention is based on the idea of cooling a fluid pump's pressure vessel by shading it from solar radiation with shade covers. The shade covers are operated with an actuator mechanism which is controlled with fluid pressure of the pressure vessel so that the operation does not require manual work. Increasing fluid pressure activates the actuator mechanism to shade the pressure vessel which the cools down and decreases the pressure which then activates the actuator mechanism to expose the pressure vessel again.

An advantage of the arrangement is that the operation is fully automated as it adapts to the amount of solar radiation it receives. Another advantage is that the pumping action is not dependent of the pumped fluid so different fluids for different applications can be pumped without affecting the operation of the fluid pump.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which

Figure 1 illustrates an embodiment of a fluid pump;

Figure 2 illustrates a system for pumping water using the fluid pump;

Figure 3 illustrates a system for pumping water by means of vaporization using the fluid pump.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 illustrates a solar powered fluid pump according to an embodiment of the invention. The fluid pump of the embodiment has a pressure vessel 12 for receiving solar radiation. The pressure vessel 12 defines a volume which can be filled with fluids such as air or water or other gases or liquids. Energy of the solar radiation converts into heat of the pressure vessel 12 which heats up the fluids contained within the pressure vessel. The pressure vessel is preferably a metal vessel which can withstand high temperatures and transfer heat effectively from its outer surface to fluids contained within the pressure vessel 12. The pressure vessel has preferably a surface which absorbs solar radiation effectively such as black paint with matte finish. The pressure inside the pressure vessel will deviate from atmospheric pressure outside the pressure vessel so it is advantageous to avoid sharp corners in the pressure vessel design. Round shapes are structurally stronger and thus a sphere and a cylinder with hemispherical heads are examples of preferred pressure vessel shapes.

The pressure vessel 12 is divided by a diaphragm 13 into two separate chambers, a first chamber and a second chamber inside the pressure vessel 12. The material and construction of the diaphragm should be chosen based on temperatures of the pressure vessel. In low temperatures a flexible rubber diaphragm works well but high temperatures may require use of a flexible or a deformable metal diaphragm. Also other suitable elastic or flexible materials or constructions may be used. In an embodiment a floating heat insulator can be used as a diaphragm. The floating diaphragm can be a disk slightly smaller in diameter than the inner diameter of the pressure vessel. The floating disk comprises one or more recesses having a through hole in the bottommost point for introducing water from below the disk onto the recesses as the pressure rises in the space above the disk, i.e. in the first chamber. The recesses are preferably shallow and wide for achieving an increased area to volume ratio of the above disk water in order to facilitate vaporizing of water and thereby increasing pressure above the floating disk.

Both chambers have an orifice 21 , 22 for input and output of fluid. The orifice may be in a form of a coupling piece, such as a threaded hose coupling or pneumatic tube coupling for convenient coupling of a tube or a hose to the pressure vessel. The two chambers may be equal in size or they can have different sizes. The dividing diaphragm can be in a form of a sheet, a pouch, a balloon, a disk or any other suitable shape.

Due to the diaphragm 13, a change in pressure in one chamber moves the diaphragm 13 or at least a part of it and changes the volume of both chambers. For example water is introduced into the first chamber and it is then sealed by closing the orifice. The second chamber can be pressurized before sealing the first chamber in order to remove any excess air from the first chamber. The sun heating the pressure vessel 12 will heat up the water in the first chamber and expand the volume of the first chamber and contract the size of the second chamber. When the water in the first chamber vaporizes the volume of the vaporized water is significantly higher than the volume of liquid water and the first chamber expands rapidly. When the orifice of the second chamber is open, fluid from the second chamber is pushed out through the orifice as the second chamber contracts in volume. If the second chamber was closed the pressure would rise in the second chamber and the contraction in volume would be smaller as the higher pressure would resist more the deformation of the diaphragm between the two chambers. If the pressure vessel is shaded or receives less solar energy, it begins to cool down. Eventually the water vapour in the first chamber begins to condensate which decreases the pressure and the volume of the first chamber rapidly and the volume of the second chamber increases. Fluid flows into the second chamber through the orifice (if it is open) as the volume of the second chamber increases. Exposing the pressure vessel to the sun again would start the process again and push fluid out from the second chamber so the pumping action of the fluid pump is achieved by intermittent cooling and heating of the pressure vessel which is achieved by controlling the solar energy which the pressure vessel receives.

The solar energy received by the pressure vessel 12 can be controlled by exposing the pressure vessel to the sun and shading the pressure vessel from the sun. Direct exposure to the sun increases received solar energy and shading decreases it. The more the pressure vessel receives solar energy, the higher its temperature will rise. The fluid pump 10 has shading means for controlling the received solar energy. Preferably the shading means function automatically so that a pumping action is achieved without manual operation by an operator. It is preferable that the controlling of the shading means is based on internal pressure of the pressure vessel. This will lower the risk of overheating and will also result a good efficiency of the pump. A timer that would expose and shade the pressure vessel at certain intervals would probably work also but it would not be an optimal solution as the solar energy received by the exposed pressure vessel is far from being a constant. A simple timer would sometimes lead to overheating of the pressure vessel and sometimes the temperatures would not rise high enough for the fluid pump to operate. The use of temperature sensors and an electronically controlled shading means would probably be the best solution where electricity and maintenance staff are readily available but electricity is typically not available in sites where solar powered devices are used. It would also significantly increase complicity of the fluid pump which in turn would make it less reliable.

In an embodiment of the invention the fluid pump 10 has shading means which comprise one or more shade covers 14 and an actuator or actuator arrangement for moving the one or more shade covers 14 between positions where the pressure vessel 12 is exposed to the sun and shaded from the sun. In Figure 1 curved shade covers 14 are presented in exposing position and shading position of the shade covers is illustrated using broken lines 14a. In the exposing position the shade covers are opened to approximately horizontal position next to the pressure vessel. The illustrated curved form of the shade covers focuses solar radiation to the pressure vessel, especially with high elevation angles of the sun. Preferably the focusing effect is further increased with a reflective surface, finishing, coating or material of the shade covers. The elevation angle of the sun varies depending on the time of year and latitude location of the fluid pump on Earth. The opening angle of the shade covers can be adjusted accordingly for focusing maximum amount of solar energy on the pressure vessel.

The shading position 14a of the shade covers 14 in this embodiment is approximately vertical. In the embodiment, two shade covers are used and the closed position resembles a closed clam expect that there is a narrowing gap from bottom to top which ultimately may close on the very top part of the fluid pump. The gap allows for air to flow next to the pressure vessel which facilitates cooling of the pressure vessel in shading position. Regardless of the shade cover structure, it's preferable to arrange a channel for air flow so that the pressure vessel cools down faster.

The movement of the shade covers is accomplished with an actuator mechanism. In the embodiment of Figure 1 , the actuator comprises a device such as a fluid spring 19, e.g. a gas spring, connected with a tube 17 to one of the orifices of the pressure vessel so that changing, e.g. increasing, pressure in one of the chambers, e.g. the second chamber, changes, e.g. increases, the pressure within the device, e.g. the fluid spring 19 and changes, e.g. increases, its length. Similarly, decrease in the pressure in the second chamber decreases the pressure within the fluid spring and decreases its length. The tube 17 connecting the fluid spring and the second chamber can be equipped with a valve 18 for to fine tuning the actuator mechanism depending on the local conditions where the fluid pump is installed. A delay can be added to the actuator mechanism by limiting the fluid flow through the valve 18.

In an embodiment the fluid spring can be a corrugated tube with sealed ends and an input/output orifice can be used. Increase in pressure straightens and elongates a corrugated tube and decrease in pressure does the opposite so it works in certain range in quite the same manner as the fluid spring. Corrugated tubes are usually readily available and therefore easy to replace as they eventually break down.

Both ends of the fluid spring are pivotally attached to arms 16 supporting on one end the shade covers 14 and hinged to each other on the opposite ends of the arms 16. Any change in length of the fluid spring changes the angle between the hinged ends of the arms and moves the shade covers towards open or closed position, i.e. exposing or shading position respectively. In the example of Figure 1 , lengthening of the fluid spring moves the shade covers towards closed position which is illustrated with broken lines and reference numbers 14a, 16a, 19a and 20a. The actuator mechanism may also comprise a spring 20, e.g. a coil spring, pivotally attached on both arms so that the spring resists lengthening of the fluid spring via the arms and facilitates the shortening of the fluid spring via the arms. The spring 20 can be adjustable for example such that one end of the spring is attached to one of the arms and the other end of the spring is attached to e.g. a threaded rod which is connected to the other arm and the rod is arranged to be moved in relation to the arm it is attached so that the spring 20 can be lengthened and shortened while the arms stay put. The adjustment on the spring can be used to fine tune the actuator mechanism depending on the local conditions where the fluid pump is installed. The spring will also facilitate the actuator mechanism to move over a straight angle of the arms where the arms are parallel to each other.

In an embodiment the fluid pump 10 comprises legs 1 1 on which the fluid pump stands so that the actuator mechanism and shade covers are elevated from ground at least enough to move freely. In an embodiment the legs support a ring which is separate from the pressure vessel and the pressure vessel is mounted on the ring to a desired position which is maintained by friction between the ring and the pressure vessel. The fluid pump can also be mounted on a floating platform with or without legs so that the fluid pump can be floating on water such as a lake, a pond, a reservoir or at sea. The floating platform can be anchored to the bottom or the water pool.

Thus an aspect of the invention can be described as a solar powered fluid pump 10 having a pressure vessel 12 for receiving solar radiation, the pressure vessel 12 being divided by a diaphragm 13 into a first chamber and a second chamber inside the pressure vessel 12, both chambers having an orifice 21 , 22 for input and output of fluid, wherein a change in pressure in one chamber moves the diaphragm 13 and changes the volume of both chambers. The fluid pump is characterized in that the fluid pump 10 comprises shading means for achieving recurring pumping action, wherein the shading means comprise one or more shade covers 14 and an actuator for moving the one or more shade covers 14 between positions where the pressure vessel 12 is exposed to the sun and shaded from the sun.

As an example of using the above described fluid pump, an air compressor system is presented. In the air compressor system water or some other liquid is introduced into the first chamber and it is then sealed by closing the orifice. The second chamber can be pressurized before sealing the first chamber in order to remove any excess air from the first chamber. The second chamber is filled with air. The sun heating the pressure vessel 12 will heat up the water in the first chamber and expand the volume of the first chamber and contract the size of the second chamber. When the water in the first chamber vaporizes the volume of the vaporized water is significantly higher than the volume of liquid water and the first chamber expands rapidly.

A hose, e.g. a pneumatic air hose, is attached to the orifice of the second chamber. The hose has a splitter dividing the hose into a first hose and a second hose which are both equipped with a one-way valve. The first hose is an input hose having its one end connected to the splitter and the other end freely on the surrounding air. The one-way valve of the first hose allows air to flow from the free end to the second chamber. The second hose is an output hose having its one end connected to the splitter and the other end connected to an air tank. The one-way valve of the second hose allows air to flow from the second chamber to the air tank.

With the above hose and valve arrangement, the pressure in the second chamber rises when the pressure in the first chamber rises until the pressure of the second chamber exceeds the pressure in the air tank. When that happens, the high pressure air from the second chamber flows through the one-way valve to the air tank. The actuator of the fluid pump begins to move the shade covers towards the shading position due to risen pressure in the first or second chamber. When the pressure vessel is shaded by the shade covers it receives less solar energy and cools down. Eventually the water vapour in the first chamber begins to condensate which decreases the pressure and the volume of the first chamber rapidly and the volume of the second chamber increases. As the pressure in the second chamber decreases below atmospheric pressure, fresh air flows through the first hose to the second chamber. The decreased pressure activates the actuator again and it now begins to move the shade covers towards exposing position and received solar energy increases again and the pressure in the first chamber rises which in turn raises the pressure in the second chamber until it exceeds the pressure in the air tank and the freshly input air flows to the air tank. The process goes on until the pressure in the air tank is substantially the same as the maximum pressure that the second chamber can reach in the prevailing conditions. In that case, the pressure within the pressure vessel remains elevated and the shade covers of the fluid pump remain in shading position until the compressed air is released from the air tank. The release lowers the pressure in the air tank and allows the air from the second chamber to flow to the air tank again which lowers the pressure in the second chamber which then activates the actuator mechanism again and moves the shade covers to exposing position and the pumping of air continues until the maximum pressure in the air tank is reached again.

Another example of using the described fluid pump is presented in Figure 2 which illustrates a system for pumping water from a deep well. The system comprises the described fluid pump 10 having a pressure vessel which is above ground level, a second pressure vessel 41 in the well water and one or more intermediate pressure vessels 42 between the above ground level pressure vessel and the well water pressure vessel. All the pressure vessels of the embodiment have similar structure of first and second chambers separated by a diaphragm. One or more chambers within the pressure vessels may have different volume compared to other chambers of the system. Also the pressure vessel may come in different sizes. Preferably the above ground pressure vessel has higher volume than the well water pressure vessel and the one or more intermediate pressure vessels.

In the system water or some other liquid is introduced into the first chamber of the above ground pressure vessel and it is then sealed by closing the orifice. The second chamber can be pressurized before sealing the first chamber in order to remove any excess air from the first chamber. The second chamber is filled with air or some other gas. The sun heating the pressure vessel 12 will heat up the water in the first chamber and expand the volume of the first chamber and contract the size of the second chamber. When the water in the first chamber vaporizes the volume of the vaporized water is significantly higher than the volume of liquid water and the first chamber expands rapidly. A hose 30, e.g. a pneumatic air hose, is attached to the orifice of the second chamber. The hose has a splitter dividing the hose into a first hose 31 and a second hose 32. The first hose is connected to the first chamber 41 a of a second pressure vessel 41 residing in the well water, i.e. well water pressure vessel. The second hose is connected to the first chamber 42a of an intermediate pressure vessel 42 which is located between the well water pressure vessel 41 and the above ground pressure vessel of the fluid pump 10. The well water pressure vessel 41 can be equipped with a float 40 attached on top of the first chamber of the well water pressure vessel to prevent the well water pressure vessel from sinking to the bottom of the well. The well water pressure vessel can also be equipped with an anchor 39, for example a link chain, attached at or below the second chamber for preventing movement of the well water pressure vessel and for maintaining an upright position of the well water pressure vessel 41 .

The orifice of the second chamber 41 b of the well water pressure vessel 41 has a splitter having an input hose 34 and an output hose 33 connected to the splitter and both hoses are equipped with a one-way valve. The input hose has its one end connected to the splitter and the other end freely on the well water. The free end can be equipped with a filter 38 to filter out any unwanted particles. The anchor 39 is preferably attached near the free end of the input hose 34 to prevent input of air in to the second chamber 41 b of the well water pressure vessel. The one-way valve of the input hose allows well water to flow from the free end to the second chamber 41 b. The output hose 33 has its one end connected to the splitter and the other end connected to a water tank 43, preferably located close to the intermediate pressure vessel 42. The one-way valve of the second hose allows well water to flow from the second chamber 41 b of the well water pressure vessel to the water tank 43.

The water tank 43 has an orifice for input and output of well water. The water tank can also comprise an air valve facilitating filling and emptying of the water tank. The orifice of the water tank 43 has a splitter receiving the output hose 33 from the well water pressure vessel as an input to the water tank 43 and an intermediate hose 35 between the water tank 43 and the second chamber 42b of the intermediate pressure vessel 42. One-way valves are installed between the water tank hose splitter and hoses 33 and 35. The one-way valves allow well water to flow from the second chamber 41 b of the well water pressure vessel 41 to the water tank and from the water tank 43 to the second chamber 42b of the intermediate pressure vessel 42.

The intermediate hose 35 between the water tank 43 and the second chamber 42b of the intermediate pressure vessel 42 has a splitter providing an output hose 36 with a one-way valve allowing water to flow from the second chamber 42b of the intermediate pressure vessel 42 to a desired location above ground where the well water is distributed or collected.

With the above hose and valve arrangement, solar radiation received by the above ground pressure vessel causes rising pressure in the first chamber of the above ground pressure vessel which decreases the volume of the second chamber of the above ground pressure vessel. Air is pushed from the second chamber of the above ground pressure vessel to the first chambers 41 a, 42a of the intermediate and well water pressure vessels and raising the pressure until a balance is reached. The second chamber 41 b of the well water pressure vessel 41 contracts and pushes water to the well water output hose 33 and from there to the water tank 43. Also the second chamber 42b of the intermediate pressure vessel 42 contracts and pushes water to the output hose 36 to above ground. When most of the well water is pushed out from the second chambers 41 b, 42b the actuator of the fluid pump 10 moves the shade covers in the shading position and the first chamber of the above ground pressure vessel contracts as the water vapour in it condensates to liquid water. That lowers the pressure in the second chamber of the above ground pressure vessel which expands causing contraction in the first chambers of the intermediate and well water pressure vessels. The second chambers of the intermediate and well water pressure vessels then expand and draw in water from the water tank 43 and from the well, respectively. When the second chambers of the intermediate and well water pressure vessels have been filled with well water, the temperatures and pressures in the chambers of the above ground pressure vessel have decreased enough to activate the actuator again which moves the shade covers to the exposing position again and the pumping process repeats itself.

More than one intermediate pressure vessels and water tanks can be used if needed due to depth of the well. Theoretically with the above arrangement it is possible to pump water from approximately 30 meters below ground without an intermediate pressure vessel. Each intermediate pressure vessel adds the usable depth by approximately 30 meters so for example two intermediate pressure vessels and water tanks are needed for pumping water from a well where water level is 80 meters below ground level. Adding of another pressure vessel is simple. The output hose 36 is connected to an additional water tank like the well water output hose 33 is connected to the water tank 43. The hose 30 has one more splitter for a third hose connected to the first chamber of an additional intermediate pressure vessel. The above ground output hose and connections between the additional pressure vessel and water tank are similar to the intermediate pressure vessel 42 and the water tank 43.

The intermediate pressure vessel and water tank may also be eliminated in case of a shallow well by using the output hose 33 for delivering the pumped water to an above ground location. Thus there is described a solar powered fluid pump system comprising a solar powered fluid pump 10 having a first pressure vessel 12 for receiving solar radiation and an at least partially submerged second pressure vessel 41 for pumping water from below ground to above ground, the pressure vessels 12, 41 being divided by a diaphragm 13 into a first chamber and a second chamber inside the pressure vessels 12, 41 , both chambers of both pressure vessels 12, 41 having an orifice 21 , 22 for input and output of fluid. The first chamber of the first pressure vessel is arranged to be sealed while operating and the second chamber of the first pressure vessel is connected with a hose to the first chamber of the second pressure vessel so that a change in pressure in one chamber moves the diaphragm 13 and changes the volume of all chambers. The system is characterized in that the fluid pump 10 comprises shading means for achieving recurring pumping action. The shading means comprise one or more shade covers 14 and an actuator for moving the one or more shade covers 14 between positions where the pressure vessel 12 is exposed to the sun and shaded from the sun. The second chamber of the second pressure vessel 41 is connected to an input hose 34 having a one-way valve allowing an input of surrounding water when the shade covers 14 are in shading position and the second chamber of the second pressure vessel 41 expands. The second chamber of the second pressure vessel 41 is connected to an output hose 33 having a one-way valve allowing an output of water from the second chamber of the second pressure vessel when the shade covers 14 are in exposing position and the second chamber of the second pressure vessel 41 contracts.

Once the water is pumped from the well to above ground, further fluid pumps can be used for distribution of the pumped water to facilities consuming the water. The above ground water is input in to the second chamber of a distribution pressure vessel through a one-way valve. The output water stream from the distribution pressure vessel flows through another oneway valve leading the water to a distribution hose or network of hoses. Further distribution pumps can be installed within the network to increase pressure and push the water into elevated locations.

In an embodiment the pressure vessel comprises two orifices in a single chamber wherein both orifices are equipped with one-way valves, one orifice being an input and the other orifice being an output. This arrangement would increase integration of the system and eliminate the need of hose splitters and separate one-way valves but at the same time would make the construction of the pressure vessel more complicated and the system more difficult to repair in case of a malfunction.

Another example of using the described fluid pump is presented in Figure 3 which illustrates a system for pumping water by vaporizing the water in low pressure. The system comprises the described solar powered fluid pump 10 which is located on ground or it can be floating on water, for example on a floating platform. The fluid pump 10 comprises a pressure vessel having a first and a second chamber separated by a diaphragm. In the system water or some other liquid is introduced into the first chamber of the above ground pressure vessel and it is then sealed by closing the orifice. The second chamber can be pressurized before sealing the first chamber in order to remove any excess air from the first chamber. The second chamber is filled in the initial state with air, water vapour, water or combination of said fluids. The sun heating the pressure vessel will heat up the water in the first chamber and expand the volume of the first chamber and contract the size of the second chamber. When the water in the first chamber vaporizes the volume of the vaporized water is significantly higher than the volume of liquid water and the first chamber expands rapidly.

The second chamber comprises two orifices, a first orifice 50 and a second orifice 52. An input hose 51 having a one-way valve allowing flow into the second chamber is attached to the first orifice 50. An output hose 53 having a one-way valve allowing flow out from the second chamber is attached to the second orifice 52. The input hose 51 is attached to an inner tube 54 of a heat exchanger. The output hose 53 is attached to an outer tube 55 of the heat exchanger, the outer tube 55 being larger in diameter than the inner tube 54 thereby defining a space between the outer tube and the inner tube of the heat exchanger. The outer tuber 55 is sealed at its ends and the outer tube comprises heat insulating material for reducing flow of heat from inside the outer tube to outside the outer tube. The output hose 53 is preferably attached to the top part of the outer tube 55 so that fluids can flow from the second chamber of the pressure vessel to the space defined between the outer and inner tubes of the heat exchanger. A water output tube 56 is preferably attached to the bottom part of the outer tube 55 so that fluids can flow from the space defined between the outer and inner tubes of the heat exchanger to an above ground location where the water is consumed or distributed further. Once the water is pumped above ground, further fluid pumps can be used for distribution of the pumped water to facilities consuming the water. The above ground water is input in to the second chamber of a distribution pressure vessel through a one-way valve. The output water stream from the distribution pressure vessel flows through another one-way valve leading the water to a distribution hose or network of hoses. Further distribution pumps can be installed within the network to increase pressure and push the water into elevated locations.

The input hose 51 is attached on top part of the inner tube 54 of the heat exchanger, which inner tube runs through the outer tube 55. The inner tube 54 is a heat conductor for effectively transferring heat from the water between the outer tube 55 and the inner tube 54 to the water inside the inner tube. The inner tube is open at the bottom part the heat exchanger is at least partially submerged in water so that the water can access the inner tube.

When the fluid pump 10 is working, temperature drop in the first chamber of the pressure vessel condenses water vapour into water and contracts the volume of the first chamber. It lowers the pressure in the second chamber and opens the one-way valve of the input hose 51 and a portion of air and water vapour from the input hose 51 flows in to the second chamber to even out the pressure differences in the second chamber and the input hose. As the pressure in the input hose 51 and the heat exchanger's inner tube 54 decreases, boiling temperature of the water within the inner tube decreases and the water starts boil and the amount of water vapour increases. The water vapour fills the input hose and the second chamber until a balance in pressure is achieved and actuator of the fluid pump activates and moves the shade covers in to exposing position. As the solar radiation heats up the pressure vessel, water in the first chamber vaporizes and expands rapidly and increases the pressure also in the second chamber which in turn increases the boiling temperature and water vapour in the second chamber condensates into warm water. The one-way valve of the output hose opens when the pressure in the second chamber has overcome the pressure in the output hose 53 and the condensed, warm water flows from the second chamber thorough the output hose 53 into the space between the outer tube 55 and the inner tube 54 of the heat exchanger. At the same time the warm water that was just introduced into the heat exchanger forces colder water from the bottom of the heat exchanger into the water output tube 56 and from there to above ground. The warm water in the heat exchanger heats the water in the inner tube of the heat exchanger and facilitates vaporizing of the water as the fluid pump actuator moves the shade covers to shading position and the process repeats itself.

The heat exchanger construction described above is a very simple example and also other typical heat exchanger constructions can be used in the embodiment. Also the output hose 53 could be connected to the inner tube 54 and the input hose 51 to the outer tube 55 and the above ground output hose would be connected to the inner tube 54 and the outer tube would be open at the bottom. The heat transfer between the tubes of the heat exchanger can be enhanced by increasing surface area of the outer surface of the inner tube.

Thus there is described a solar powered fluid pump system comprising a fluid pump 10 having a pressure vessel 12 for receiving solar radiation, the pressure vessel 12 being divided by a diaphragm 13 into a first chamber and a second chamber inside the pressure vessel 12, both chambers having an orifice 21 , 22 for input and output of fluid, wherein a change in pressure in one chamber moves the diaphragm 13 and changes the volume of both chambers. The fluid pump is characterized in that the fluid pump 10 comprises shading means for achieving recurring pumping action, wherein the shading means comprise one or more shade covers 14 and an actuator for moving the one or more shade covers 14 between positions where the pressure vessel 12 is exposed to the sun and shaded from the sun. The first chamber is arranged to be sealed having an amount of first fluid, such as water in it. The second chamber is connected with an input hose 51 and an output hose 53 to a heat exchanger comprising two tubes (54, 55) within each other for transferring heat between said tubes so that water from the second chamber is arranged to flow through the output hose 53 having a one-way valve to the heat exchanger when the shade covers 14 are in exposing position and the second chamber of the second pressure vessel 41 contracts. Water vapour is arranged to flow from the heat exchanger through the input hose 51 having a one-way valve to the second chamber when the shade covers 14 are in shading position and the second chamber of the second pressure vessel 41 expands. The heat exchanger comprises a water output hose 56 through which the water cooled in the heat exchanger is arranged to flow when the shade covers 14 are in exposing position and the second chamber of the second pressure vessel 41 contracts and water from the second chamber flows to the heat exchanger.

Any particles, live bacteria and dissolved substances that exist in the water within the inner tube of the heat exchanger are removed effectively as the water is boiled and transferred as water vapour, i.e. steam, to the second chamber. The last described embodiment of the fluid pump system can be used for cleaning and desalination of water using direct solar energy.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. A solar powered fluid pump (10) having a pressure vessel (12) for receiving solar radiation, the pressure vessel (12) being divided by a diaphragm (13) into a first chamber and a second chamber inside the pressure vessel (12), both chambers having an orifice (21, 22) for input and output of fluid, wherein a change in pressure in one chamber moves the diaphragm (13) and changes the volume of both chambers, characterized in that the fluid pump (10) comprises shading means for achieving recurring pumping action, wherein the shading means comprise one or more shade covers (14) and an actuator for moving the one or more shade covers (14) between positions where the pressure vessel (12) is exposed to the sun and shaded from the sun.

2. A solar powered fluid pump according to claim 1, characterized in that the actuator of the shading means is connected to the pressure vessel (12) by a tube and operated by a fluid pressure of one of the chambers of the pressure vessel (12).

3. A solar powered fluid pump according to claim 1 or 2, characterized in that said one or more shade covers (14) have a reflective surface for focusing solar radiation to the pressure vessel (12) when said one or more shade covers (14) are in the position where pressure vessel (12) is exposed to the sun.

4. A solar powered fluid pump according to any one of claims 1 to 3, characterized in that said actuator for moving the one or more shade covers (14) comprises a gas spring (19), connected with a tube (17) to the pressure vessel (12) so that increasing pressure in one of the chambers of the pressure vessel (12) increases the pressure within the gas spring (19) and increases its length, both ends of the gas spring (19) being pivotally attached to arms (16), the arms supporting on one end the shade covers (14) and hinged to each other on the opposite ends of the arms (16), wherein a change in the length of the gas spring (19) changes the angle between the hinged ends of the arms and moves the shade covers (14) towards exposing or shading position.

5. A solar powered fluid pump according to any one of claims 1 to 4, characterized in that said diaphragm (13) is a flexible diaphragm.

6. A solar powered fluid pump as claimed in any one of claims 1 to 5, characterized in that the orifice of the first chamber is arranged to be closed and the orifice of the second chamber is arranged to be open when the fluid pump (10) is operating so that the first chamber expands in volume when the pressure vessel (12) and the fluids in its chambers heat up thereby pushing fluid out from the second chamber through the orifice, and so that the first chamber contracts in volume when the pressure vessel (12) and the fluid in its chambers cool down thereby pulling fluid in to the second chamber through the orifice.

7. A solar powered fluid pump according to claim 6, characterized in that the fluid in the first chamber is liquid and the fluid in the second chamber is gas.

8. A solar powered fluid pump system comprising a solar powered fluid pump (10) having a first pressure vessel (12) for receiving solar radiation and an at least partially submerged second pressure vessel (41) for pumping water from below ground to above ground, the pressure vessels (12, 41) being divided by a diaphragm (13) into a first chamber and a second chamber inside the pressure vessels (12, 41), both chambers of both pressure vessels (12, 41) having an orifice (21 , 22) for input and output of fluid, wherein the first chamber of the first pressure vessel is arranged to be sealed while operating and the second chamber of the first pressure vessel is connected with a hose to the first chamber of the second pressure vessel so that a change in pressure in one chamber moves the diaphragm (13) and changes the volume of all chambers, characterized in that the fluid pump (10) comprises shading means for achieving recurring pumping action, wherein the shading means comprise one or more shade covers (14) and an actuator for moving the one or more shade covers (14) between positions where the pressure vessel (12) is exposed to the sun and shaded from the sun, and in that the second chamber of the second pressure vessel (41) is connected to an input hose (34) having a one-way valve allowing an input of surrounding water when the shade covers (14) are in shading position and the second chamber of the second pressure vessel (41 ) expands, and in that the second chamber of the second pressure vessel (41 ) is connected to an output hose (33) having a one-way valve allowing an output of water from the second chamber of the second pressure vessel when the shade covers (14) are in exposing position and the second chamber of the second pressure vessel (41 ) contracts.

9. Use of the solar power fluid pump of claim 1 for compressing air to an air tank.