Abstract:
An apparatus employing pressure transients for transporting fluids from one reservoir to another, includes an at least partly enclosed space, and a body herein, where the body is movable relatively to the interior of the space. The apparatus further includes an opening in the enclosed space to allow a fluid to flow alternately in the direction into and out, and conduits in fluid communication with the opening and connected to the reservoirs. Further, an object is arranged to collide with the body so as to generate pressure transients in the partly enclosed space in order to produce a flow of fluid in the direction from the partly enclosed space towards the second reservoir, and to produce a flow of fluid in the direction from the first reservoir towards the partly enclosed space.

Description:
FIELD OF THE INVENTION 
     This invention relates to transport of fluids by an apparatus described in the introductory part of claim  1 . More specifically the invention relates to an apparatus which employs pressure transients to transport fluids. Moreover, the invention describes exemplary applications where the energy needed to generate said pressure transients are captured from ocean waves. Hence, in these applications the described apparatus operates as an apparatus for capturing the energy in ocean waves. 
     BACKGROUND 
     There is one type of device for transporting fluids that has almost been forgotten, or overlooked for practical reasons which employs a physical phenomenon commonly known as “Water Hammer”. The first device of this type was built in 1772 by J. Whitehurst for use in a brewery and is classified as “Hydraulic ram pumps” or just “Ram pumps”. 
     “Water Hammer” is a phenomenon that occurs when a fluid flowing in a pipeline experience a sudden halt by e.g. closing a valve, thereby causing the fluid motion to generate a pressure transients. However, the “Ram pumps” also employ the reversed process, i.e. where pressure transients produces a fluid flow. The reversed process is not part of the “Water Hammer” phenomena, and it has mostly been ignored resulting in a close to non-existing theoretical knowledge about this process.  FIG. 1  illustrates a prior art “Ram pump” where a flow of fluid is sent through a “Drive pipe” and a “Waste valve” is employed to generate a positive pressure transient within a “Valve box”. The positive pressure transient is subsequently producing a flow of fluid that transfers at least a fraction of the supplied fluid to the “Storage tank”. The transferred fluid is the same fluid that prior to the transfer was flowing in the “Drive pipe”, and a “Ram pump” is thus a pumping device which utilizes a small fall of fluid to lift a fraction of the supplied fluid to a height that is greater than the initial height of the fluid. 
     The “Water Hammer” phenomenon also occurs if a body, which is in contact with a fluid at rest, experiences a sufficiently sudden movement, since this is, due to symmetry of relative motion, essentially the same as a sudden halt of a flowing fluid by closing of a valve. An equation relating the pressure transients to the fluid flow speed was formulated by the Russian scientists Nikolai Joukowsky. This equation states that Γ=ρcu, where Γ is the pressure transient, ρ is the density of the fluid, c is the sound speed in the fluid and u is the fluid flow velocity. N. Joukowsky published this equation in 1898 after extensive experiments of the “Water Hammer” phenomena in long steel pipes, and is hence commonly known as the Joukowsky equation. However, the same equation was introduced by the German scientist Johannes von Kries in 1883 based on his studies of blood flow in the arteries. 
     In industrial pumping application mostly three kinds of pressures are observed: static pressure, pressure waves and pressure transients. 
     Static pressure is employed in all fluid transporting devices today with only one exception, namely applications where “Ram pumps” are used. Fluids are transported by the gradient of static pressure along the pipelines which the pumping device has established in the system. The static pressure is constant in time during the normal steady state operation of the pumping device, but the pressure is time dependent during the start up of the pump until a steady state is reached. Hence, in the initial phase a pumping device can produce pressure waves. A purely static pressure is not possible to obtain in any industrial pumping application since there will always be some disturbances in the steady state operation. However, various means are applied in order to maintain a close to static situation. 
     A pressure wave is not capable of generating a net transport of fluids since pressure waves only generate oscillations in a fluid but no net transport. An example of pressure waves are sound waves in air. Notice that the disturbances mention above are mostly pressure waves, and hence one employ different procedures to minimize the generation of these useless pressure waves. 
     If a pumping device makes a sudden stop due to some failure of the operation of the pump, a pressure transient can be generated in the same way as in the case of a sudden closing of a valve. 
     In many industrial applications “Water Hammer” is regarded as a dangerous phenomenon that should be avoided due to the plausible occurrence of disruptive cavitations generated by the pressure transients. The pressure transient Γ, which is positive in the beginning, can change sign to become negative due to interactions with some solid surfaces in the system. If the sum of the local pressure and the pressure transient is less than the vapor pressure, cavities containing vapor are formed. After some time the cavity will collapse (implode), i.e. when the pressure in the neighborhood again rises above the vapor pressure. The cavity walls thus rush towards one another thereby generating hard impulse on the system owing to the low degree of compressibility of liquids. The impulses spreading out from each collapsed cavity is an important, and usually undesirable, feature, often heard as disturbingly loud noises in applications such as water supply systems and hydraulic pumps. Most seriously, the continual collapse of cavities leads rapidly to deterioration and erosion of nearby solid surfaces. To summarize one can state that during the “Water Hammer” phenomena all of the positive pressure transients become negative pressure transients, and all of the negative pressure transients are generating disruptive cavitations. Hence, to actively generate the “Water Hammer” phenomena for industrial applications have not been considered feasible among experts in the field. 
     Pressure transients are avoided in industrial applications, mainly since they would normally lead to disruptive cavitations in the system as in the case of the “Water Hammer” phenomena. One of many reasons to actively produce pressure transients is that pressure transients can be both positive and negative as mention above, and thus pressure transients in a partly enclosed space with one or more openings can produce a flow in the direction out of and into the partly enclosed space. This effect is apparent from the Joukowsky equation Γ=ρcu, thus when Γ is positive u is positive (flow in the direction out of a partly enclosed space), and when Γ is negative u is negative (flow in the direction into a partly enclosed space). In this way both positive and negative pressure transients generate flows, thereby suppressing disruptive cavitations due to negative pressure transients. Notice that only one fraction of the positive pressure transients produces a flow, whereas the other fraction become negative pressure transients due to the abovementioned interactions at some solid surfaces in the system. Since the pressure transients cannot be simultaneously negative and positive, such inflows and outflows may in principle occur through the same opening. The possibility of applying only one opening is an important uniqueness of the described apparatus compared with all fluid transporting devices today that employs one opening for the inflow and one for the outflow. The only exception is the “Ram pump” that has one more opening for the “Waste valve”, thus a “Ram pump” has three openings. 
     How does the “Ram pump” avoid the disruptive cavitations that normally occur during the “Water Hammer” phenomena? Looking at  FIG. 1  one realizes that the “Drive pipe” and the “Supply head” ensures that any disruptive cavitations which are about to develop within the “Valve box” are terminated by a sufficient inflow of fluid from the “Drive pipe”. Hence the sum of the local pressure and the pressure transients are not allowed to become less than the vapor pressure due to this inflow. In other words, any negative pressure transient in the “Valve box” is generating a negative flow (a flow into the “Valve box”) according to the Joukowsky equation. It is important to notice that the hydrostatic head given by the “Supply head” needs to be large enough so that said inflow becomes sufficient to in order to avoid any disruptive cavitations. 
     What is a pressure transient? There are many ways of generating a static pressure or a pressure wave, but there are only a few known situations where pressure transients occur. The most known case where pressure transients appear is during the “Water Hammer” phenomenon. Pressure transients are a time dependent propagating phenomenon like pressure waves, but unlike pressure waves fluids can be transported by pressure transients in accordance with the Joukowsky equation. 
     To find out what pressure transients are one need to know more about the concept of pressure in fluids. On a microscopic level pressure is the results of the thermal motion of the particles in the fluid, and one can interpret pressure as energy density in the fluid. However, on a macroscopic level pressure is more commonly regarded as the ability of the fluid to exert a force on a body. The force F that the pressure p inside a hydraulic cylinder can push the piston (body) with is given by F=Ap, where A is the size of the surface of the piston which is in contact with the fluid in the hydraulic cylinder. Hence, a general method of producing a pressure p inside a hydraulic cylinder is to act on the piston (body) with a force F obtaining a pressure given by p=F/A. In this way a static pressure can be generated by a constant force, and a pressure wave is obtained by employing a time dependent oscillating force. 
     To our knowledge, pressure transients can only be generated by a collision process. The momentum of a fluid flowing in a pipeline (with cross section σ) disappears during a time interval Δt after a valve is suddenly closed, and due to the conservation of momentum something must be created during this time interval Δt. To find out what is happening one can follow the work by N. Joukowsky. Newton second law can be written in the momentum form RΔt=Δ(mu), where F is the force, Δt is a time interval and Δ(mu) is the change in momentum of a body with mass m and velocity u. Applying that a pressure transient can be expressed as Γ=F/σ one can write that ΓσΔt=ρuV=ρuσL=ρuσcΔt, where σ is the cross section of the pipeline, Δt is the time interval during which the momentum ρu disappears, V=σL is the volume V of the part of the fluid (with density ρ) where the momentum has disappeared, and L is the length that the pressure transient Γ has propagated with the sound speed c during the time interval Δt. Hence, the Joukowsky equation Γ=ρcu is obtained. 
     One could argue that the pressure transient C is generated by a force F as in the case of an ordinary static pressure p, since the relation Γ=F/σ is employed. This is, however, a force that appears in a collision process and the only way to produce such a force is to perform a collision. As mentioned above, pressure transients can be produced by a body (which is in contact with a fluid at rest) which experiences a sufficiently sudden movement. It is now possible to specify more precisely what kind of movement that is needed in order to obtain pressure transients. The movement of said body must be generated by a collision process. The collision process can be obtained with an object (having a nonzero momentum) colliding with said body. More precisely, a collision process is an event where said object is set in motion at time τ and gains a nonzero momentum (during a time interval T) before it collides with said body at a later time τ+T. 
     The pressure loss p along a pipeline with length L during laminar constant flow is given by the Hagen-Poiseuille equation p=32μLu/d 2 , where μ is the coefficient of viscosity and u is the fluid flow velocity. Introducing the cross section σ=πd 2 /4 of the pipeline, the Hagen-Poiseuille equation can be written as p=8πμLu/σ. Hence, an ordinary pumping device must produce a static pressure that is equal to the pressure loss p in order to maintain the fluid flow velocity u in the pipeline. In the case of turbulent flow the pressure loss can be estimated with the Darcy-Weisbach equation p=2fLρu 2 /d if an empirical friction factor f is introduced, and the dependence of the friction factor f with the Reynolds number is often illustrated in Moody diagrams. It is important to notice that the relation between the flow velocity u and pressure p in both the Hagen-Poiseuille and Darcy-Weisbach equations are different from the relation obtained with the Joukowsky equation Γ=ρcu, hence there is a fundamental difference in how a pressure p and a pressure transient Γ can produce a fluid flow velocity u. 
       FIG. 8  displays a prior art piston pump where a piston is connected to a machinery, but the mechanical movement of the piston by the machinery is not able to generate pressure transients inside the hydraulic cylinder. 
     A prior art piston pump is also shown in  FIG. 9 , but now the piston is moved by a fluid expanding in a chamber. This chamber could be a combustion chamber and the expanding fluid could be some kind of fossil fuel, and again no pressure transients could be produced in the hydraulic cylinder.  FIG. 10  outlines a prior art displacement pump where a fluid expanding in the chamber pushes the membrane and thus transport fluid out of the hydraulic cylinder. Such a prior art displacement pump is also disclosed in U.S. Pat. No. 3,586,461. However, the motion of the membrane produces no pressure transients in the hydraulic cylinder. 
     All the prior arts pumps illustrated in the  FIGS. 8-10  and disclosed in U.S. Pat. No. 3,586,461 have one thing in common. They are not able to generated pressure transients, since their operations do not involve any collision process. Hence, the described apparatus therefore employs a heavy object that collides with the piston in order to obtain pressure transients in the hydraulic cylinder. 
     Problems to be Solved by the Invention 
     Based on the state of the known art the objective with the invention is to provide a robust and efficient apparatus for transporting fluids by employing pressure transients, and where the need of a “Waste valve” and a “Drive pipe” ( FIG. 1 ) to generate said pressure transients are removed. 
     One objective with the invention is to provide an apparatus for transporting fluids that is new in many fundamental aspects. The apparatus produces a pulsating fluid flow that is different from the flow obtained with ordinary pumps, but to some extent similar to that of the “Ram pump”. The “Ram pump” and the described apparatus both employ pressure transients to transport fluids. However, the “Ram pump” generates these transients by opening and closing a “Waste valve”, whereas the described inventive apparatus generates such pressure transients utilizing a sudden movement of at least one body (piston). Said movement must be sufficiently sudden, and in the described apparatus this is obtained by at least one object (a hammer) colliding with said body (piston). 
     SUMMARY OF THE INVENTION 
     According to the invention said objectives are achieved by an apparatus for transport of fluids as stated in the introduction, and having the characteristic features stated in the independent claim  1 . Advantageous embodiments of the invention are stated in the remaining dependent claims. 
     More specifically, the invention relates to an apparatus employing pressure transients for transporting fluids comprising at least one partly enclosed space, at least one body in said at least one partly enclosed space, where said at least one body is movable relatively to the interior of said at least one partly enclosed space, at least one opening in said at least one enclosed space which allows a fluid to flow alternately in the direction into and out of said at least one partly enclosed space, at least one first conduit and at least one second conduit in fluid communication with at least one of said at least one opening, at least one first reservoir and at least one second reservoir connected to said at least one first conduit and at least one second conduit respectively, at least one first mechanical unit and at least one second mechanical unit in said at least one first conduit and at least one second conduit respectively, where said at least one first mechanical unit only allows flow in said at least one first conduits from said at least one first reservoir and towards said at least one partly enclosed space, and said at least one second mechanical unit only allows flow in said at least one second conduit in the direction from said at least one partly enclosed space and towards said at least one second reservoir. 
     The invention is further characterized in that at least one positive pressure transient is generated in at least one of said at least one partly enclosed space by at least one object, with nonzero momentum, colliding with said at least one body, where at least part of said at least one positive pressure transient produces flow of fluid out of said at least one partly enclosed space through said at least one second mechanical unit and into said at least one second reservoir, and at least one negative pressure transient is generated in said at least one partly enclosed space, where said at least one negative pressure transient, together with the resulting at least one hydrostatic head between at least one of said at least one first reservoirs and at least one of said at least one partly enclosed space, produce flow of fluid out of said at least one first reservoir through said at least one first mechanical unit and into said at least one partly enclosed space. 
     An advantageous embodiment of the invention is to terminate any disruptive cavitations occurring in said partly enclosed space by assuring a sufficient flow of fluid into said partly enclosed space(s). Preferably this is obtained by arranging at least one of said first reservoir(s) with a sufficiently hydrostatic head between at least one of said partly enclosed space(s) and at least one of said first reservoir(s), so that said sufficient flow of fluid comes from at least one of said first reservoir(s). 
     Preferably at least one of said partly enclosed space(s) and at least one of said body or bodies are a hydraulic cylinder and a piston, respectively. 
     Another advantageous embodiment is to arrange at least one chamber that is filled with a mixture of liquid and gas, wherein one or more third conduits are connected to the liquid filled parts of the chamber(s). Said third conduit(s) is/are in fluid communication with said partly enclosed space(s) through said second mechanical unit(s). Preferably at least one membrane suitable for separating gas and liquid is arranged within at least one of said chamber(s). Said chamber(s) may e.g. be any kind of pressure tanks and/or hydraulic accumulators. 
     Said first and second mechanical units are with advantage valves of specific types such as one-way valves, check valves, restrictor check valves, throttle check valves, restrictor one-way valves or/and throttle one-way valves. 
     Furthermore, said conduits consist preferably of pipelines, e.g. pipelines made of stainless steel and/or plastic. 
     As an alternative to the above-described embodiments the inventive apparatus may be employed in one or more heat exchanging systems such as heating or cooling systems. This may be achieved by merging at least one of said first reservoir(s) with at least one of said second reservoir(s), thereby obtaining at least one common reservoir into which both an inflow and an outflow of fluid are present. 
     Another possible application using one or more of the above-mentioned embodiments is to employ at least one of said at least one second reservoir as a hydropower reservoir. Moreover, in some other applications at least one of said reservoir(s) might be replaced by a pressure tank, and at least one of said pressure tank(s) could be connected to hydropower turbine(s). 
     Another possible application is to use the apparatus as described above and claim  1 - 8  as an energy converting system, wherein at least one of said object(s) is/are connected to at least one wave motion capturing system. 
     One apparatus having connected said wave motion capturing system, and thus suitable for capturing energy in wave motions, has one or more objects connected to one or more floating buoys which may be set in motion by waves. Said motions are then generating movements of said object(s), thereby causing a non-zero momentum of said object(s) prior to the collision(s) with at least one of said body or bodies. 
     Said object(s) is/are preferably connected to one or more buoy(s) by one or more cord(s) running through pulleys, wherein at least one pulley is/are anchored to at least one sinker, and at least one of the other pulleys is/are connected to a fixed construction. 
     In another, alternative apparatus with said wave motion capturing system, and thus suitable for capturing energy in wave motions, said object(s) is/are connected to at least one wall which can be set in motion by waves, and that the motion of said at least one wall induces movement of said object(s), and thereby obtaining a nonzero momentum of said object(s) prior to collision with at least one of said body or bodies 
     Said object(s) in the latter described apparatus is/are preferably connected to said wall with at least one cord running through one or more pulleys that are linked to a fixed construction and where said wall(s) is/are anchored to at least one sinker with one or more joints. 
     The inventive apparatus may be produced employing known components, and the invention is not by any means limited to neither choice of material during the manufacturing of components such as said object(s), nor how said object(s) are moved towards and away from said piston(s). However, one possible method of achieving such movement of the object(s) is to apply ocean waves as mentioned above. Ocean waves are in nature a periodic or quasi-periodic phenomenon, which may contain large amount of energy. Hence the described apparatus may constitute an ocean wave energy converting system as described above when at least one of said at least one second reservoir is a hydropower reservoir. More specifically, the inventive apparatus may be applied as said ocean wave energy converting system(s) in which said object(s) constitute a part of an ocean wave motion capturing system(s). Such an apparatus allows the construction of an ocean wave power concept where said ocean wave motion capturing system(s) and said ocean wave energy converting system(s) are fully disconnected. This ocean wave power concept would most probably lead to a more robust solution compared to prior art solutions. For ocean wave motion capturing systems either prior art systems or new innovative solutions may be employed to assure a movement of the object(s) due to the ocean waves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a Prior Art “Ram pump” where a flow of fluid is sent through a “Drive pipe”, and a “Waste valve” is employed to generate a pressure transient within a “Valve box”. 
         FIG. 2  shows one possible embodiment of the inventive apparatus employing, in addition to reservoirs, conduits and check valves, a hydraulic cylinder, an object and a piston to produce sufficient pressure transients to transfer fluid from one reservoir to another. 
         FIG. 3  outlines another embodiment of the inventive apparatus where the hydraulic cylinder has only one common opening. 
         FIG. 4  illustrates another embodiment of the inventive apparatus where there is only one reservoir and both first and second conduits are connected to said reservoir. 
         FIG. 5  shows another embodiment of the inventive apparatus where the two fluid transport applications are performed with only one hydraulic cylinder. 
         FIG. 6  outlines another embodiment of the inventive apparatus where two hydraulic cylinders are employed to perform a fluid transport application. 
         FIG. 7  illustrates another embodiment of the inventive apparatus with an additional chamber mounted on the second conduit leading to the second reservoir. 
         FIG. 8  shows an embodiment of a Prior Art piston pump. 
         FIG. 9  outlines an embodiment of a Prior Art piston pump. 
         FIG. 10  illustrates an embodiment of a Prior Art displacement pump. 
         FIG. 11  shows an application of the inventive apparatus in order to capture the energy in ocean wave motions applying a buoy that is floating in the ocean. 
         FIG. 12  outlines an application of the inventive apparatus in order to capture the energy in ocean wave motions applying a wall that is partly submerged into the ocean. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The invention will be disclosed with reference to the drawings wherein: 
       FIG. 2  shows a possible embodiment of the inventive apparatus comprising a system with the following components; a hydraulic cylinder  201  with first and second openings  204 , 205 , a piston  202 , first and second pipe lines  211 , 212  that is connected to first and second openings  204 , 205  respectively, first and second reservoirs  231 , 232  connected to first and second pipe lines  211 , 212 , first and second check valves  221 , 222  in first and second pipe lines  211 , 212  respectively, and an object  208  which can collide with piston  202 . First check valve  221  only allows the fluid to flow in the direction from first reservoir  231  and towards hydraulic cylinder  201 , while second check valve  222  only allows fluid to flow in the direction from hydraulic cylinder  201  and towards second reservoir  232 . 
     The total head, i.e. the sum of the hydrostatic head and the friction head, between second reservoir  232  and hydraulic cylinder  201  is larger than the total head, i.e. the hydrostatic head plus the friction head, between first reservoir  231  and hydraulic cylinder  201 . Notice that the hydrostatic head between first reservoir  231  and hydraulic cylinder  201  might be larger than the hydrostatic head between second reservoir  232  and hydraulic cylinder  201  even if the difference in the total head is reversed. This would be the case when the friction head is largest between second reservoir  232  and hydraulic cylinder  201 . 
     Object  208  collides with the end of a piston  202 , and the sudden movement of piston  202  caused by the collision generates positive pressure transients in hydraulic cylinder  201  which again generate a fluid flow in the direction from the hydraulic cylinder  201  through second check valve  222  and towards second reservoir  232 . First and second check valves  221 , 222  ensure that the positive pressures transient only produce a flow in the above described direction due to their one-way directional properties. 
     A fraction of the positive pressure transients is likely not to be converted into a fluid flow. Instead this fraction will interact with the solid surfaces within the apparatus, thereby transforming the fraction of positive pressure transients into negative pressure transients within hydraulic cylinder  201 . The negative pressure transients generate a fluid flow in the direction from first reservoir  231  through first check valve  221  and towards hydraulic cylinder  201 . First and second check valves  221 , 222  ensure that the negative pressure transients only produce a flow in the above described direction due to the one-way directional properties of valves  221 , 222 . Notice that the hydrostatic head between first reservoir  231  and hydraulic cylinder  201  also contributes to the generation of the described fluid flow. 
       FIG. 3  outlines a possible embodiment of the inventive apparatus comprising a system with the following components; a hydraulic cylinder  301  with one opening  304 , a piston  302 , first and second pipe lines  311 , 312  that are both connected to a third conduit  310 , which again is connected to opening  304 , first and second reservoirs  331 , 332  connected to first and second pipe lines  311 , 312  respectively, first and second check valves  321 , 322  arranged in first and second conduits  311 , 312 , respectively, and an object  308  which can collide with piston  302 . First check valve  321  only allows the fluid to flow in the direction from first reservoir  331  and towards hydraulic cylinder  301 , while second check valve  322  only allows fluid to flow in the direction from hydraulic cylinder  301  and towards second reservoir  332 . 
     In this embodiment the hydraulic cylinder has only one opening  304  which is connected to a third conduit  310 . First and second conduits  311 ,  312  are connected at one of their ends to the third conduit  310  and at their opposite ends to first and second reservoirs  331 , 332 , respectively. In the embodiment show in  FIG. 3  and described herein only one opening  304  may be applied in hydraulic cylinder  301  since the positive and negative pressure transients do not appear at the same time in hydraulic cylinder  301 , hence allowing the fluid to alternately flow into and out of hydraulic cylinder  301  through same opening  304 . In addition, the pressure transients do not have the possibility to generate flow through two different openings as in  FIG. 2  thus increasing the efficiency compared to the previously mentioned embodiment. 
       FIG. 4  illustrates an alternative embodiment of the inventive apparatus comprising a system with the following components; a hydraulic cylinder  401  with one opening  404 , a piston  402 , first and second pipe lines  411 , 412  that are both connected to a third conduit  410 , which again is connected to opening  404 , first and second reservoirs  431 , 432  connected to first and second pipe lines  411 , 412  respectively, first and second check valves  421 , 422  arranged in first and second conduits  411 , 412 , respectively, and an object  408  which can collide with piston  402 . First check valve  421  only allows the fluid to flow in the direction from first reservoir  431  and towards hydraulic cylinder  401 , while second check valve  422  only allows fluid to flow in the direction from hydraulic cylinder  401  and towards second reservoir  432 . Moreover, in this embodiment first reservoir  431  and second reservoir  432  are merged to constitute one common reservoir  430 . 
     This embodiment has only one common reservoir  430  in which both first and second conduits  411 , 412  are connected. Such embodiment is advantageous when applied as heat exchange systems such as heating or cooling systems. One example of the latter application is storage of hot or cold fluid in reservoir  430 , using first and second conduits  411 , 412  as climate distributors to the surrounding environment. 
       FIG. 5  shows a possible embodiment of the inventive apparatus comprising a system with the following components; a hydraulic cylinder  501  with one opening  504 , a piston  502 , one first and second pipe lines  511 , 512  that are connected to one third conduit  515 , which again is connected to a fourth conduit  510 , which again is connected to opening  504 , one first and second reservoirs  531 , 532  connected to first and second pipe lines  511 , 512  respectively, one first and second check valves  521 , 522  in first and second pipe lines  511 , 512  respectively, one additional first and second pipe lines  513 , 514  that are connected to one additional third conduit  516 , which again is connected to fourth conduit  510 , one additional first and second reservoirs  533 , 534  connected to additional first and second pipe lines  513 , 514  respectively, one additional first and second check valves  523 , 524  in additional first and second pipe lines  513 , 514  respectively, and an object  508  which can collide with piston  502 . Moreover, in this embodiment first reservoir  531  and second reservoir  532  are merged to constitute one common reservoir  530 . 
     One of said first check valves  521  only allows the fluid to flow in the direction from first reservoir  531  and towards the hydraulic cylinder  501 , while one of said second check valves  522  only allows fluid to flow in the direction from hydraulic cylinder  501  and towards second reservoir  532 . Another of said additional first check valves  523  only allows the fluid to flow in the direction from said additional first reservoir  533  and towards hydraulic cylinder  501 , while said additional second check valves  524  only allows fluid to flow in the direction from hydraulic cylinder  501  and towards said additional second reservoir  534 . 
     The embodiment shown in  FIG. 5  is capable of fulfilling all the functionalities of the embodiments illustrated in  FIGS. 3 and 4  applying only one hydraulic cylinder  501 . Moreover, if check valves  521 , 522 , 523 , 524  are replaced with other type of valves such as restrictor check valves or throttle check valves the flow energy from hydraulic cylinder  501  to each of the fluid transport applications may be more precisely regulated. 
       FIG. 6  outlines a possible embodiment of the inventive apparatus comprising a system with the following components; a first hydraulic cylinders  601  with one first opening  604 , a second hydraulic cylinder  606  with one second opening  605 , a first and second pistons  602 , 607 , first and second pipe lines  611 , 612  both connected to a third conduit  610 , which again is connected to a fourth conduit  613  and a fifth conduit  614 , first and second reservoirs  631 , 632  connected to first and second pipe lines  611 , 612  respectively, first and second check valves  621 , 622  in first and second pipe lines  611 , 612  respectively, an object  608  which can collide with pistons  602 , 607 , where fourth conduit  613  and fifth conduit  614  are connected to first and second openings  604 , 605  respectively. First check valve  611  only allows the fluid to flow in the direction from first reservoir  631  and towards first and second hydraulic cylinders  601 , 606 , while second check valve  632  only allows fluid to flow in the direction from first and second hydraulic cylinders  601 , 606  and towards second reservoir  632 . 
     This embodiment applies two hydraulic cylinders  601 , 606  to perform one fluid transport application. The inventive apparatus is hence not limited to only one hydraulic cylinder for each fluid transport application. Furthermore, one hydraulic cylinder is not limited to perform only one fluid transport application, as described above. 
       FIG. 7  illustrates another embodiment of the inventive apparatus comprising a system with the following components; a hydraulic cylinder  701  with first and second openings  704 , 705 , a piston  702 , first and second pipe lines  711 , 712  that is connected to first and second openings  704 , 705  respectively, first and second reservoirs  731 , 732  connected to first and second pipe lines  711 , 711 , first and second check valves  721 , 722  in first and second pipe lines  711 , 712  respectively, a chamber  740  connected to second conduit  712  between the second check valve  722  and the second reservoir  732  through a third conduit  713 , and an object  708  which can collide with piston  702 . First check valve  721  only allows the fluid to flow in the direction from first reservoir  731  and towards hydraulic cylinder  701 , while second check valve  722  only allows fluid to flow in the direction from hydraulic cylinder  701  and towards second reservoir  732  and/or chamber  740 . 
     Chamber  740  may be a pressure tank or a hydraulic accumulator, and thus a fraction of or all fluids flowing through second check valve  722  can flow into chamber  740 . Chamber  740  is preferably filled with both liquid and gas and only the liquid filled part is connected to third conduit  713 . The liquid and gas may be separated by a boundary such as a membrane as in the case of a hydraulic accumulator. Such embodiment decreases the resistance of the fluid flow in second conduit  712  since the gas in chamber  740  compresses during the inflow of the fluid from third conduit  713  and thus fluid can flow more easily into chamber  740  than into second reservoir  732 . The gas starts to decompress when the fluid flow through second check valve  722  stops and the flow into chamber  740  halts. As a result of the gas decompression fluid begins to flow out of chamber  740  through third conduit  713 , where one-way directional second check valve  722  ensures that the fluid flows from chamber  740  into second reservoir  732 . 
     The effect of such arrangement causes more fluid to be transferred to second reservoir  732  per collision. This again serves two purposes:
         1. The efficiency of the inventive apparatus increases   2. The flow of fluid into second reservoir  732  becomes more continuous.
 
The method of connecting a chamber  740  as illustrated in  FIG. 7  and described above can also be employed in all the embodiments outlined in  FIG. 2-6  and described above.
       

       FIG. 8  outlines a possible embodiment of a prior art piston pump comprising a system with the following components; a hydraulic cylinder  801  with one opening  804 , a piston  802 , first and second conduits  811 , 812  both connected to a third conduit  810 , which again is connected to opening  804 , first and second reservoirs  831 , 832  connected to first and second conduits  811 , 812  respectively and first and second check valves  821 , 822  in first and second conduits  811 , 812  respectively. Piston  802  is directly connected to a machinery device  803  that is capable of moving piston  802 . 
     The prior art piston pump shown in  FIG. 8  has some resemblance with the possible embodiment of the inventive apparatus illustrated in  FIG. 3 . There are however some important differences. One obvious distinction is that piston  802  is directly connected to machinery device  803 , in contrast to piston  302  in  FIG. 3 . Moreover, piston  802  is set in motion by machinery device  803 , whereas piston  302  shown in  FIG. 3  experiences a sudden movement when object  308  collides with the end of piston  302 . In addition, check valves  821 , 822  must be close to hydraulic cylinder  801  whereas check valves  321 , 322  may be arranged far from hydraulic cylinder  301 . Check valves  821 , 822  are thus often integrated in the piston pump and hence it becomes a fluid transport device with two openings, which is in contrast to the inventive apparatus shown in  FIG. 3  where check valves  321 , 322  may be placed far from hydraulic cylinder  301  and hence constitute an apparatus for fluid transport with only one opening  304 . 
       FIG. 9  illustrates a possible embodiment of a prior art piston pump comprising a system with the following components; a hydraulic cylinder  901  with one opening  904 , a piston  902 , first and second conduits  911 , 912  both connected to a third conduit  910 , which again is connected to opening  904 , first and second reservoirs  931 , 932  connected to first and second conduits  911 , 912  respectively and first and second check valves  921 , 922  in first and second conduits  911 , 912  respectively. Piston  902  is directly connected to a chamber  903  where an expanding fluid is capable of moving piston  902 . 
     Piston  902  has one end that is inside hydraulic cylinder  901  and the other end is inside chamber  903 . Piston  902  is moved by a fluid which can expand inside chamber  903  and thus move piston  902 . The movement of piston  902  by the expanding fluid inside the chamber  903  shown in  FIG. 9  and the mechanical movement of piston  802  by the machinery  803  outlined in  FIG. 8  have one thing in common. The movements by piston  802  and  902  are not sufficiently sudden in order to generate pressure transients inside hydraulic cylinders  802  and  902  respectively. The reason for this is that the movements are not obtained by a collision process as described in the introductory part. 
       FIG. 10  shows a possible embodiment of a prior art displacement pump comprising a system with the following components; a hydraulic cylinder  1001  with one opening  1004 , a membrane  1002 , first and second conduits  1011 , 1012  both connected to a third conduit  1010 , which again is connected to opening  1004 , first and second reservoirs  1031 , 1032  connected to first and second conduits  1011 , 1012  respectively and first and second check valves  1021 , 1022  in first and second conduits  1011 , 1012  respectively. Membrane  1002  constitutes a separation of hydraulic cylinder  1001  from a chamber  1003  where an expanding fluid is capable of moving membrane  1002 . 
     Membrane  1002  is moved by a fluid which can expand inside chamber  1003  and thus move membrane  1002 . Movement by membrane  1001  is not able to generate pressure transients inside hydraulic cylinder  1002 . The reason for this is that the movement is not obtained by a collision process as described in the introductory part. 
       FIG. 11  outlines a possible embodiment of the inventive apparatus comprising a system with the following components; a hydraulic cylinder  1101  with one opening  1104 , a piston  1102 , first and second pipe lines  1111 , 1112  that are both connected to a third conduit  1110 , which again is connected to opening  1104 , first and second reservoirs  1131 , 1132  connected to first and second pipe lines  1111 , 1112  respectively, first and second check valves  1121 , 1122  arranged in first and second conduits  1111 , 1112 , respectively, and an object  1108  which can collide with piston  1102 . First check valve  1121  only allows the fluid to flow in the direction from first reservoir  1131  and towards hydraulic cylinder  1101 , while second check valve  1122  only allows fluid to flow in the direction from hydraulic cylinder  1101  and towards second reservoir  1132 . Furthermore, object  1108  is connected to a floating buoy  1150  with a wire  1180  which is running through two pulleys  1170 ,  1171  where one pulley  1170  is anchored to a sinker  1160  and the other pulley  1171  is linked to a fixed construction  1190 . 
     Floating buoy  1150  is floating in the ocean and can be set in motion by the ocean waves, and thus producing a movement of object  1108 . Hence, object  1108  gains a nonzero momentum before it collides with body  1102 . 
       FIG. 12  illustrates a possible embodiment of the inventive apparatus comprising a system with the following components; a hydraulic cylinder  1201  with one opening  1204 , a piston  1202 , first and second pipe lines  1211 , 1212  that are both connected to a third conduit  1210 , which again is connected to opening  1204 , first and second reservoirs  1231 , 1232  connected to first and second pipe lines  1211 , 1212  respectively, first and second check valves  1221 , 1222  arranged in first and second conduits  1211 , 1212 , respectively, and an object  1208  which can collide with piston  1202 . First check valve  1221  only allows the fluid to flow in the direction from first reservoir  1231  and towards hydraulic cylinder  1201 , while second check valve  1222  only allows fluid to flow in the direction from hydraulic cylinder  1201  and towards second reservoir  1232 . Furthermore, object  1208  is connected to a wall  1250  with a wire  1280  which is running through a pulley  1271  which is linked to a fixed construction  1290  and where wall  1250  is anchored to a sinker  1260  with a joint  1270 . 
     Wall  1250  is partly submerged into the ocean and can be set in motion by the ocean waves, and thus producing a movement of object  1208 . Hence, object  1208  gains a nonzero momentum before it collides with body  1202 .