Abstract:
The hydroelectric power generating system incorporates a man-made dam structure configured to completely enclose a body of water. The dam is preferably filled by pumping seawater into the reservoir defined by the encircling dam. A circumferential canal feeds water to one or more penstocks. Each penstock has one or more hydroelectric turbine generators installed therealong. The penstocks feed an enclosed circumferential channel about the base of the dam. The channel delivers water to a pump that pumps the water back into the bottom of the reservoir. An auxiliary hydroelectric power generating system disposed within the dam utilizes the water exiting from the lower end of the penstocks for additional production of energy. While this system results in a net loss of energy, the system can make use of surplus power to drive the return pump during periods of low electrical demand in order to replenish the reservoir.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of my presently pending U.S. Non-Provisional patent application Ser. No. 14/156,408, filed on Jan. 15, 2014, which claims the benefit of my U.S. Provisional Patent Application Ser. No. 61/753,302, filed Jan. 16, 2013. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical power generating systems, and particularly to a hydroelectric power generating system incorporating man-made reservoirs that each have one or more penstocks extending from a common waterway and one or more electrical generating turbines disposed along each of the penstocks. 
     2. Description of the Related Art 
     Hydroelectric power generating systems have been known for a considerable period of time. Conventional systems utilize a natural geographic basin, valley, or the like, and place a man-made dam across a channel in the natural terrain to create a reservoir upstream of the dam. The water is then made to flow through one or more power generating turbines in the dam (or in a powerhouse constructed with the dam), to generate electrical power. Generally, only a single generating turbine is installed in each penstock of the facility, although multiple penstocks are common in a single conventional hydroelectric power generating system. 
     An example of such a conventional hydroelectric power generating system is found in Japanese Patent Publication No. 9-177,654, published on Jul. 11, 1997. This reference describes (according to the drawings and English abstract) a hydroelectric power generating system incorporating a single penstock run with multiple generating turbines installed therealong. One embodiment is illustrated having an upstream reservoir and dam and a second downstream reservoir and dam, and generating turbines installed downstream of each dam. 
     Another example is found in Chinese Patent Publication No. 2,880,912 published on Mar. 21, 2007 to Wu Jinnan. A plurality of generating turbines is installed in series along stepped concrete bases downstream of the dam. 
     Thus, a hydroelectric power generating system solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The hydroelectric power generating system comprises a man-made dam structure that completely encircles a water reservoir enclosed therein. The water may be pumped from a variety of sources, such as the ocean, as well as rivers, lakes, and streams. The man-made dam structure and transport of the water enables the hydroelectric power generating system to be constructed virtually anywhere, so long as there is sufficient land available for the facility. The dam may be substantially circular, or may have any other desired configuration. At least one sluice gate, and preferably a plurality of such gates, feeds a peripheral canal near the top of the dam. The peripheral canal, in turn, feeds at least one penstock, and preferably a plurality of such penstocks. Each penstock includes at least one electrical generating turbine, and preferably a plurality of such turbines, therealong. The downstream end of the penstock or penstocks feed into an enclosed circumferential channel within the base of the dam. A return line extends from the channel through the base of the dam and into the reservoir. A pump is installed in the return line, enabling water to be pumped from the return line back into the reservoir. While this system results in a net loss of energy, it does enable the reservoir to be replenished during periods where surplus electrical energy is available. 
     The system uses water to generate essentially “clean” energy. Construction of a sufficient number of such facilities, and/or of sufficient water volume, would result in some slight reduction in sea level as water is drawn from the oceans to the reservoirs. The reservoirs would also serve as convenient water recreational sites, as any number of such facilities could be constructed convenient to large population centers, as opposed to conventional hydroelectric dams and their reservoirs. The hydroelectric power generating system would make use of salt water from the sea, rather than fresh water. The dissolved salt and minerals in the water may prove to be of some benefit to some individuals. Also, it is anticipated that the relatively large volume of ocean water captured within the dams would provide a practical environment for the farming of many ocean-dwelling fish and other marine life, as well as serving to protect endangered species of marine life. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic perspective view of a hydroelectric power generating system according to the present invention, illustrating its general features. 
         FIG. 2  is a diagrammatic elevation view in section of the hydroelectric power generating system according to the present invention, illustrating further details thereof. 
         FIG. 3  is a diagrammatic perspective view of another embodiment of a hydroelectric power generating system according to the present invention, illustrating its general features. 
         FIG. 4  is a diagrammatic sectional view of the hydroelectric power generating system shown in  FIG. 3 , illustrating its general features. 
         FIG. 5  is a diagrammatic perspective view of a turbine for the hydroelectric power generating system shown in  FIG. 3 . 
         FIG. 6A  is a diagrammatic sectional view of an auxiliary power generating system in the hydroelectric power generating system shown in  FIG. 3 , illustrating its general features. 
         FIG. 6B  is a diagrammatic sectional view of another embodiment of an auxiliary power generating system in the hydroelectric power generating system shown in  FIG. 3 , illustrating its general features. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The hydroelectric power generating system greatly expands upon the availability of conventional hydroelectric power systems, using a relatively small man-made dam extending across a natural channel to form a reservoir enclosed by natural terrain. While such facilities are quite valuable for the power they produce, as well as for their recreational and flood control benefits, the number of such facilities is limited by the lack of availability of natural terrain permitting their construction and efficient operation. 
       FIG. 1  of the drawings provides a diagrammatic perspective view of an exemplary hydroelectric power generating system  10  according to the present invention. The system  10  incorporates a relatively large dam  12  or wall defining a dam that completely encircles or laterally encloses a reservoir  14  therein. The dam  12  may have a generally cylindrical configuration, as shown in  FIG. 1 , or may have any other desired external shape or configuration. The dam  12  includes at least one sluice gate  16  (and preferably a plurality of sluice gates  16 ) extending through the upper portion  18  thereof. The sluice gates  16  permit the flow of water from the upper levels of the reservoir  14  through the dam  12  and into an externally disposed peripheral canal  20  that surrounds the upper portion  18  of the dam  12 . 
     At least one penstock  22  (preferably a plurality of penstocks  22 ) extends from the peripheral canal  20  downward through the interior  24  of the dam  12  to an internal collection channel  26  disposed within the base  28  of the dam  12 . The penstocks  22  do not descend vertically within the interior  24  of the dam  12 , but describe helical arcs as each of the penstocks  22  traverses a portion of the circumference of the dam  12 , generally as illustrated in  FIGS. 1 and 2  of the drawings. Each penstock  22  includes at least one (and preferably a plurality of) hydroelectric turbine generator  30  installed therealong. The installation of a plurality of generators  30  in each penstock  22  provides additional power recovery from the energy developed by the water as it continues to flow through the penstock from the uppermost generator  30 . 
     Water flows from the upper level of the reservoir  14  through the sluice gates  16  and into the peripheral upper canal  20 . Water flow through the sluice gates  16  may be controlled by conventional gate valves or the like. The water then flows downward through the penstocks  22  to operate the generators  30  for electrical power generation. Each of the penstocks  22  may also include a conventional gate valve or other water control or shutoff device. The water then flows from the lower ends of the penstocks  22  into the internal collection channel  26  within the interior  24  of the base  28  of the dam  12 . A return passage  32  extends from the collection channel  26  and the lower level of the reservoir  14 , as shown in  FIG. 2 . As water seeks its own level, it will be seen that there will be no net flow through the system when the water level in the reservoir  14  is equal to the water level in the peripheral canal  20 . However, a pump  34  is provided in or along the return passage  32  to deliver water from the collection channel  26  back into the reservoir  14 . While only a single return passage  32  and pump  34  are shown, it will be understood that a plurality of return passages and pumps may be provided, if desired. While the power required to operate the pump  34  is greater than the power generated by the hydroelectric turbine generators  30 , the pump  34  may be operated at times of low electrical power demand by consumers to enable the hydroelectric power generating system  10  to function. A powerhouse  36  is provided external to the base  28  of the dam  12  to control and distribute electrical power generated by the system, and to control and operate the pump  34  as well. A conventional external energy source provides the energy to operate the powerhouse. 
     The system  10  as described above is a closed system, i.e., water is not permitted to escape the system, except by evaporation and/or leakage. This is because the water to be used in the system  10  is taken from the sea, i.e., it is salt water unsuited for irrigation or potable consumption. The salt water is pumped from a suitable oceanic source through a seawater delivery line  38  that communicates with the reservoir  14 , as shown in  FIG. 1 , to fill the reservoir volume  14  initially. The use of seawater with the hydroelectric power generation system  10  may provide a number of benefits. The construction of a large number of very large systems on otherwise unusable land (desert, etc.) could accept a small percentage of the water of the present oceans and seas of the planet, and thereby reduce the rising sea level trend that has developed, at least to some small extent. The recreational value of such installations when constructed near large population centers has been noted further above. Some persons may find that swimming or bathing in the salt water may provide certain benefits, and the construction of such systems convenient to their homes serves to facilitate access. The relatively large volume of salt water contained by very large dams  12 , or by a series of such dams  12 , will provide support for a large number of fish and other marine animals. These fish and/or marine animals may be harvested for edible consumption, and/or the reservoir volumes may serve as habitats for endangered species. Accordingly, the present hydroelectric power generating system provides a number of benefits in addition to potential power production. 
       FIGS. 3-5 ,  6 A, and  6 B of the drawings shows another embodiment of a hydroelectric power generating system  110 , which includes features that enhance the utilization of hydrodynamics to produce energy. Referring to  FIG. 3  of the drawings, the hydroelectric power generating system  110  incorporates a relatively large dam  112  or wall defining a dam that completely encircles or laterally encloses a reservoir  114  therein, and an auxiliary power generating system  150  within said reservoir  114 . The dam  112  can have a generally cylindrical configuration, as shown in  FIG. 3 , or may have any other desired external shape or configuration. The dam  112  includes at least one sluice gate  116  (and preferably a plurality of sluice gates  116 ) extending through the upper portion  118  thereof and an annular tunnel  140  within the interior  124  of the base  128  of the dam  112 , as generally illustrated in  FIG. 4  of the drawings. The sluice gates  116  permit the flow of water from the upper levels of the reservoir  114  through the upper portion  118  and into an externally disposed peripheral canal  120  that surrounds the upper portion  118  of the dam  112 . 
     At least one penstock  122  (preferably a plurality of penstocks  122 ) extend downward from the peripheral canal  120  through the interior  124  of the dam  112 . The penstocks  122  do not descend vertically within the internal structure  124  of the dam  112 , but are arranged in a step configuration and describe generally helical arcs as each of the penstocks  122  traverses a portion of the circumference of the dam  112 . As such, the step configuration follows a general spiral curve. Each penstock  122  includes at least one (and preferably a plurality of) hydroelectric turbine generator  130   a  installed therealong. The installation of a plurality of hydroelectric turbine generators  130   a  in each penstock  122  provides additional power recovery from the energy developed by the water as it continues to flow downward through the penstock  122  from the uppermost hydroelectric turbine generator  130   a . The step configuration provides stable support and allows for greater variety in the arrangement and utilization of multiple hydroelectric turbine generators  130   a  in each penstock  122 . Depending on the amount of energy required, it is possible to increase the number of penstocks in the interior  124  of the dam  112  by widening the peripheral canal  120 . 
     The hydroelectric turbine generation system  110  functions substantially similar to the previous embodiment in that water flows from the upper level of the reservoir  114  through the sluice gates  116  and into the peripheral canal  120 . Water flow through the sluice gates  116  may be controlled by conventional gate valves or the like. The water then flows downward through the penstocks  122  to operate the hydroelectric turbine generators  130   a  for electrical power generation. Each of the penstocks  122  can also include a conventional gate valve or other water control or shutoff device. The water then flows from the lower end of the penstocks  122  into the annular tunnel  140  within the interior  124  of the base  128  of the dam  112 . The annular tunnel  140  is adapted to house an internal collection channel  126  and a return passage  132 . The return passage  132  defines a fluid conduit extending from the annular tunnel  140  to the auxiliary power generation system  150 . The annular tunnel  140  provides space for at least one additional hydroelectric turbine generator to increase power capacity. 
     Referring to  FIG. 4 , as the water flows downward through the penstocks  122  from the externally disposed peripheral canal  120 , the flowing water provides the hydrodynamic forces to operate the hydroelectric turbine generators  130   a  in order to convert the same into useable energy. At the lower end of the dam  112  the flowing water enters the internal collection channel  126  located within the annular tunnel  140  where additional power can be generated by the additional hydroelectric turbine generator contained therein. 
     The additional hydroelectric turbine generator can be the same as the hydroelectric turbine generator  130   a  disposed in the stepped areas of the penstock  122 . However, there can be instances in which much of the pressure head can be lost or low. In order to compensate for this lost pressure, the annular tunnel  140  can be provided with another embodiment of a turbine, as illustrated in  FIG. 5 . The turbine  142  can be a very low head turbine, which includes a plurality of blades  144  radiating in a fan configuration. The blades  144  are desirably configured so that minimal hydrodynamic forces are required to rotate the same. It is to be noted that the turbine  142  can operate even when pressure loss is minimal. 
     After the water flows through the annular tunnel  140 , the water is expelled through respective return passages  132 . A pump  134  is provided in or along the return passage  132  to deliver water from the internal collection channel  126  towards the auxiliary power generating system  150  when the pressure of the expelled water is not enough to propel the water from the internal collection channel  126  into the auxiliary power generation system  150 . While only a single annular tunnel  140  and pump  134  are shown, it will be understood that a plurality of these components can be provided, if desired. As in the first embodiment, while the power required to operate the pump  134  can be great, the pump  134  can be operated at times of low electrical power demand by consumers to enable the hydroelectric power generating system  110  to function. A powerhouse  136  is provided external to the base  128  of the dam  112  to control and distribute electrical power generated by the system, and to control and operate the pump  134  as well. A conventional external energy source provides the energy to operate the powerhouse. 
     Unlike the previous of the hydroelectric power generator  10 , the hydroelectric power generator system  110  utilizes the water expelling from the lower portion of the penstocks  122  to generate additional power through the auxiliary power generation system  150 . The auxiliary power generating system  150  of the hydroelectric power generating system  110  includes an elongated column  152  extending from the bottom of the reservoir  114  toward the top of the reservoir  114 , as generally illustrated in  FIG. 3  of the drawings. Due to the operating environment, the column  152  is provided with a relatively wide base  153  to provide a stable support. As shown, the base can be constructed as a substantially conical flute. It should be noted, however, other variants of the base can be provided for the base such as block support structures or any other desired shape that can provide stability. The column  152  can have a generally cylindrical configuration, as shown in  FIG. 3 , or can have any other desired external shape or configuration. The column  152  is in communication with at least one compressor unit  155 , such as an air compressor unit, that creates air current and includes at least one (and preferably a plurality of) hydroelectric turbine generator  130   b  installed within the column  152 . The hydroelectric turbine generators  130   b  can be arranged along the circumference of the inner wall of the column  152 , as generally illustrated in  FIG. 4  of the drawings, on at least one (and preferably a plurality of) horizontal support beam  156  within the column  152 , as generally illustrated in  FIG. 6A  of the drawings, on at least one (and preferably a plurality of) vertical support beam  158  within the column  152 , as generally illustrated in  FIG. 6B  of the drawings, or can be arranged in a combination of these configurations. 
     Referring to  FIGS. 6A and 6B , the water flowing out of the return passage  132  and into the auxiliary power generating system  150 , it is mixed with air from the compression unit  155  once in the column  152 . The water pressure at the exit is preferably high to move water up the column  152 . High pressure can be provided by several different mechanisms. For example, the return passage  132  can be construed so that is progressively constricts towards the outlet, a nozzle can be provided at the outlet, the pump  134  can be operated at high pressure, and the like. As the water is being introduced into the column  152 , it is aerated by the air blowing into the column  152  from the compressor unit  155  that provides air through at least one inlet  154 . The return passage  132  can be arranged so that the outlet thereof enters the column  152  at a substantial tangent so as to induce swirling and mixing of the water and air. The aerated water flows upward through the column  152  with sufficient velocity and momentum to operate the at least one hydroelectric turbine generator  130   b  located within the column  152  for electrical power generation. After the water is propelled upward through the hydroelectric turbine generators  130   b , the aerated water expels back into the reservoir  114  as depicted by the arrows in  FIGS. 6A and 6B  of the drawings. 
     The embodiment auxiliary power generation system illustrated in  FIG. 6B  is substantially the same as that shown in  FIG. 6A . However, the auxiliary power generation system  150  includes a plurality of vertical support beams  158  arranged in a circular pattern forming a substantially cylindrical cage. Unlike  FIG. 6A  the substantially cylindrical cage does not have an outer wall, the vertical support beams  158  are free-standing from the base  153 . Cross support can be provided by horizontal support beams, as illustrated by the horizontal support beams  156   b.    
     The alternative embodiment of the hydroelectric power generating system  110  as generally illustrated in  FIGS. 3-5 ,  6 A, and  6 B of the drawings is a closed system, i.e., water is not permitted to escape the system, except by evaporation and/or leakage. This is because the water to be used in the hydroelectric power generating system  110  is taken from the sea, i.e., it is salt water unsuited for irrigation or potable consumption. The salt water is pumped from a suitable oceanic source through a seawater delivery line  138  that communicates with the reservoir  114 , as shown in  FIG. 3 , to fill the reservoir volume  114  initially. The use of seawater with the hydroelectric power generation system  110  may provide a number of benefits. The construction of a large number of very large systems on otherwise unusable land (desert, etc.) could accept a small percentage of the water of the present oceans and seas of the planet, and thereby reduce the rising sea level trend that has developed, at least to some small extent. The recreational value of such installations when constructed near large population centers has been noted further above. Some persons may find that swimming or bathing in the salt water may provide certain benefits, and the construction of such systems convenient to their homes serves to facilitate access. The relatively large volume of salt water contained by very large dams  112 , or by a series of such dams  112 , will provide support for a large number of fish and other marine animals. These fish and/or marine animals may be harvested for edible consumption, and/or the reservoir volumes may serve as habitats for endangered species. The hydroelectric power generating system can be adapted to include a filtration system to prevent any unwanted materials, such as trash, from entering the hydroelectric power generating system and obstructing the hydroelectric power generators. The filtration system can also be adapted to include a mechanism to control bacteria to protect the hydroelectric turbine generators from failing. Accordingly, the present hydroelectric power generating system provides a number of benefits in addition to potential power production. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.