US 20100117372 A1
A thermal energy system comprises a primary thermal energy system, a solar thermal energy system, a burner, and a heat recovery system. The solar thermal energy system comprises a pipe for absorbing heat from solar rays. The burner is arranged such that the pipe of the solar thermal energy system is capable of absorbing heat from the burner. The heat recovery system uses thermal energy from at least one of the primary and solar thermal energy sources.
1. A thermal energy system comprising:
a primary thermal energy system;
a solar thermal energy system comprising a pipe for absorbing heat from solar rays;
a burner, where the burner is arranged such that the pipe of the solar thermal energy system is capable of absorbing heat from the burner; and
a heat recovery system that uses thermal energy from at least one of the primary and solar thermal energy sources.
2. A method comprising the steps of:
providing a primary thermal energy system;
providing a solar thermal energy system comprising a pipe for absorbing heat from solar rays;
arranging a burner such that, when the burner generate heats, the pipe of the solar energy system absorbs heat generated by the burner; and
recovering the thermal energy from at least one of the primary and solar thermal energy sources.
3. A hybrid wind turbine comprising:
blades supported on a hub;
a generator operatively connected to the hub such that rotation of the blades operates the generator;
an engine operatively connected to the generator such that operation of the motor operates the generator;
a solar thermal energy system; and
a heat recovery system; wherein
the heat recovery system uses exhaust heat from the generator and heat collected by the solar thermal energy system.
This application (Attorney Matter No. P216290) is a continuation in-part of U.S. patent application Ser. No. 12/022,958 filed Jan. 30, 2008, now U.S. Pat. No. 7,615,884 issued Nov. 10, 2009.
U.S. patent application Ser. No. 12/022,958 claims priority of U.S. Provisional Application Ser. No. 60/898,619 filed Jan. 30, 2007.
The contents of all related application listed above are incorporated herein by reference.
The present invention relates in general to wind turbine technology, and more particularly to a system combining the apparatus and method of the wind turbine with other energy sources.
While wind turbine power has many advantages as an additional and/or alternative source of energy, it does have the drawback that there are time intervals where it is not able to produce any power at all, or only a small amount of power. Thus, there have been various approaches to combine the wind power source with other independent power sources to be able to produce power more reliably, in the form of “firm power”.
A search of the patent literature has disclosed patents related to solving these problems, and these are summarized in the following text.
U.S. Pat. No. 4,204,126 (Diggs) discloses a “Guided Flow Wind Power Machine With Tubular Fans”, which, when powered by the wind, can generate electricity. Also, when there is enough wind power it has the capability of also lifting “massive weights” hydraulically. Then when the wind has subsided, the weights can be permitted to be drop downwardly to supply energy to drive a generator.
U.S. Pat. No. 5,740,677 (Vestesen) shows a system which is adapted to for use at a location where there is a need for electricity and also fresh water. However, this residential community is also near a source of salt water. There is a wind diesel plant which supplies electricity for various uses and also operates a distillation unit to supply the fresh water. The wind/diesel plant comprises at least an internal combustion engine, a wind turbine, a distillation unit, a first closed fluid circuit containing heating and cooling devices, and a second open fluid circuit.
U.S. Pat. No. 6,127,739 (Appa) issued Oct. 3, 2000, and is the first of three patents which have the same inventor. In this patent, there is a forward front rotor 12 having blades that would cause rotation in one direction, then there is a rear rotor 21 (called a “leeward rotor 21”) positioned behind the front rotor 12 and rotating in the opposite direction. This patent states that the various items added to this apparatus would produce a substantially higher “value of energy efficiency factor”.
U.S. Pat. No. 6,278,197 (Appa) is the second patent to the inventor and it discloses a wind turbine where there is a forward set of turbine blades which rotate in one direction, and a second set of turbine blades which are in the wake of the first set and which rotate in the opposite direction. The reason given for this is that there is still energy in the air that passes through the first set of turbine blades, and this is utilized in the second set of turbine blades.
U.S. Pat. No. 6,492,743 B1 (Appa) is the third (and more recent) patent to Mr. Appa, and this also shows a basic configuration of wind turbine where there are forward and rear sets of blades. There is a heat exchanger having a centrifugal fan to circulate ambient air to cool an alternator in the apparatus, and the hot air is directed to a combustion chamber by means of an air duct in the blades. Natural gas or liquid is also conveyed to the rotating frame. When wind speed is low, fuel will be injected into the combustion chamber and burned with a large mass of air. The hot gasses expand in an exit nozzle to provide thrust to assist wind power.
The present invention may be embodied as a thermal energy system comprising a primary thermal energy system, a solar thermal energy system, a burner, and a heat recovery system. The solar thermal energy system comprises a pipe for absorbing heat from solar rays. The burner is arranged such that the pipe of the solar thermal energy system is capable of absorbing heat from the burner. The heat recovery system uses thermal energy from at least one of the primary and solar thermal energy sources.
The present invention may also be embodied as a method comprising the following steps. A primary thermal energy system is provided. A solar thermal energy system comprising a pipe for absorbing heat from solar rays is provided. A burner is arranged such that, when the burner generate heats, the pipe of the solar energy system absorbs heat generated by the burner. Thermal energy from at least one of the primary and solar thermal energy sources is recovered.
The present invention may also be embodied as a hybrid wind turbine comprising blades supported on a hub, a generator, an engine, a solar thermal energy system, and a heat recovery system. The generator is operatively connected to the hub such that rotation of the blades operates the generator. The engine is operatively connected to the generator such that operation of the motor operates the generator. The heat recovery system uses exhaust heat from the generator and heat collected by the solar thermal energy system.
It is believed that a clearer understanding of the present invention can be obtained by first reviewing briefly the overall system of a first example of the present invention, as shown in
To proceed now with the more general description of the first example, as indicated above, this will be done with reference to
The entire power generating section 16 comprises a blade section 18, a rotary speed changing drive section 20, a generator section 22, and an auxiliary power section 24. The blade section 18 comprises a plurality of turbine blades 28, and a hub or rotor 30 to which the blades 18 are connected.
The blade section 18 and the speed changing drive section 20 can be grouped as the primary power generating portion while the auxiliary power section 24 (as well as the auxiliary power or back up power components, including those that are shown in other examples) can be considered as being in a secondary power generating portion.
The primary and secondary power generating portions together function in a manner to enable the generator 22 to provide firm power.
With the overall description of this first example being presented, attention is now directed to
This drive section 34 is commonly in the form of a gear section. In general, the rotational speed of the low speed shaft 32 would be between about 30 to 60 rotations per minute, and the gear section 34 is in turn connected to the generator 22 to cause it to rotate at a speed between about 1,200 to 3,600 RPM. This would typically be a rotational speed required by a large number of present day generators to produce electricity. The gear section 34 connects to a shaft 38 which is located in the generator 22.
There is provided an anemometer 40 which measures the wind speed, and also a wind vane 42 to ascertain wind direction. Both the wind speed and the wind direction data are transmitted to a controller 44. The controller 44, as its name implies, performs various control functions. For example, it controls a yaw drive 46 and its associated motor 48 to keep the blade section 18 facing into the wind as the wind direction changes, starts and stops the wind turbine, etc. There is also provided a disc brake 49 for the low speed shaft 32, and in the prior art this can be applied mechanically, electrically, or hydraulically to stop the rotation of the rotary components in emergencies.
All, or most all, of the components which are shown in
All (or many) of the components of this first example are shown in at least one of
To proceed now with a description of the first example of
The components of this first example described in the paragraph immediately above, are already found in
For convenience of description, in describing the location of the components in
To return now to the description of this first example, the auxiliary drive unit 24 a provides a rotating drive output to a torque converter 66. The torque converter 66 in turn has a drive connection to an overrunning drive member 68 (which can be simply an overrunning drive clutch) that in turn connects to the rear end of the high speed shaft 38 a of the generator 22 a. Then the forward end of the shaft 38 a of the generator 22 a connects to a forward overrunning drive member 69 that connects to the drive output of the speed changing drive section 34 a. The torque converter 66 located between the auxiliary drive unit 24 a and the generator 22 a may or may not be required and depends on the design speed of the generator 22 a and the auxiliary drive unit 24 a. If the operating speed of the auxiliary drive unit 24 a is a close match to the generator 22 a operating speed, the overrunning clutch 68 would provide an adequate method of coupling the generator 22 a to the auxiliary drive unit 24 a.
There are many types of conventional drives that could function as the auxiliary drive unit 24 a. For example, this could include an internal combustion engine, external combustion engine, steam turbine, steam engine, or hybrid drive. The most common types of drives would include, but not be limited to, gasoline engines, diesel engines, natural gas engines, gas turbine engines, steam turbines, steam engines, sterling engines, gas expanders, or hydraulic or electric motors with a nearby source of power or hydraulic energy. Sources of energy for the auxiliary drive unit 24 a could include gasoline, diesel, jet fuel, heavy oil, natural gas, propane, hydrogen, ethanol, coal, wood, or any other energy source suitable for the auxiliary drive or its cooperating equipment.
To describe now the operating features of this first example, let us review three different situations, namely: i. the wind is at a sufficient velocity so that it is able to generate sufficient power to produce the desired power output of the generator 22 a; ii. the wind velocity is not sufficient to drive the blade section at all, and the auxiliary drive section 24 a is activated to generate the needed electric power; and iii. the wind velocity is such that it is able to rotate the blade section 18 a to generate only an electrical power output which is below the desired output of the generator 22 a, and to obtain the desired level of the total electrical power output, it is necessary to operate the auxiliary drive section 24 a.
In the first situation (where the wind power is at a sufficiently high level), the blade section 18 a is rotated to drive the blade sections 18 a at full power output or near full power output. More specifically, the blade section 18 a is rotating with sufficient power output so that the speed augmenting drive section 20 a is acting through an overrunning clutch 69 to drive the generator 22 a at a sufficient power output so that sufficient electrical power is developed. The overrunning drive section 68, which connects to the shaft 38 a of the generator 22 a, simply overruns its connection to the auxiliary drive section 24 a, thus, the auxiliary drive section 24 a remains stationary.
Let us now take the second situation where there is either no wind or such a small velocity of the wind that the blade section 18 a is put in a position where it is stationary or simply not rotating. In this situation, the auxiliary drive section 24 a is activated manually or automatically so that its rotational output is directed through the torque converter 66, which in turn acts through the overrunning drive 68, which is caused to rotate in a direction so that it drives the generator 22 a.
At the same time, the speed changing drive section 20 a remains stationary, and since the connection between the drive section 20 a and the generator 22 a is the overrunning drive member 69, the generator 22 a is able to operate to rotate in a manner so that it has no drive connection with the drive section 20 a and is driven totally by the auxiliary power unit 24 a.
Let us now consider the third situation, which is that the wind generated power is great enough to achieve a useful lower power output level, but is not great enough to meet the desired power output. In this instance, the auxiliary drive section 24 a would be utilized to cause rotation of its torque converter 66 to act through its drive member 68 and provide power to the rear end of the shaft 38 a of the generator 22 a.
At the same time, the pitch of the blades 28 a could be set at an angle of attack to optimize the power output that is developed by the use of both power sources. The effect of this is that the shaft 38 a of the generator 22 a would be driven at both its front and rear end portions, so that there would be sufficient power to generate the desired electrical power output.
Also, in this third operating mode, the two overrunning drive members (drive clutches) 68 and 69 are operating in their engaged position, so that these are providing rotational forces to the generator 22 a at a sufficiently high power output.
Let us now turn our attention to some of the possible applications of the system of the first example of the invention (i.e., the various ways it might be used). As indicated earlier in this text, one of the drawbacks of a wind turbine is that it produces power intermittently. Thus, this puts wind power in the category of “non-firm energy producers”. However, by combining the wind power turbine in the combination of this first example, this now becomes a source of firm power that could supply energy to a power grid on a continuous basis.
Another situation of possible use is where there is a municipality which needs a reliable source of electricity. With the system of the first example, the system could be engineered so that the auxiliary power source by itself could generate an adequate level of electric power. In that situation, the auxiliary power source would be able to operate as the sole power source in that time interval when the wind turbine power source would be idle. Then as the wind energy was available, the system could be operated in the mode mentioned above as Mode 1 or Mode 2 where the electric power output would be entirely from the wind turbine or as Mode 3, a dual drive mode, where the combined operation of both the wind turbine and the auxiliary power section are utilized to drive the generator 22 a.
From the above comments, it becomes apparent that only the one generator 22 a would be needed in each of the three modes. There are various expenses incurred in providing electric power through a generator, such as the cost of switchgear, transformers, etc. With this arrangement of this example, that extra expense is alleviated by utilizing the same generator for: i) the “only wind power mode”; ii) the “sole auxiliary power mode”; and iii) the “combined wind power/auxiliary power mode”.
It is to be understood that all of the components (or a large number of the components) that are shown in
To comment generally on the generator 22 a, wind turbines are supplied with several different types of generators, including induction generators, double fed induction generators (for speed control), variable slip induction generators (for limited changes in speed), synchronous generators (directly and indirectly connected), and DC generators (typically small wind turbines). Most wind turbines in service are standard induction generators which are constant speed machines. Variable speed generators, with the exception of DC generators, can be held at a fairly constant speed with the control system. This is a plus for the operation of the auxiliary drive in that the additional energy input to the generator does not change the generator speed appreciably. Additional torque input to the generator simply causes more power output from the generator. The DC generator is not considered an ideal candidate for the auxiliary drive as too much torque from the auxiliary drive could speed up the wind turbine to the point where the wind would not contribute to energy production.
To comment generally about the different possibilities of the auxiliary drive 24 a, it could be coupled directly to the generator via a torque converter or overrunning clutch or it can be connected through a gearbox, again using a torque converter or overrunning clutch. In most cases, an overrunning clutch will be sufficient; however, if there is a need to run the engine at constant speed and vary the output shaft speed to the generator, a torque converter can be used. If the wind turbine is at rest (zero speed) and the operator wishes to run the generator, he can start the auxiliary drive 24 a. Because the generator is at rest, the overrunning clutch will engage the generator as soon as the auxiliary drive commences startup. The generator rotor will rotate along with the auxiliary drive shaft during startup and will continue to rotate at the same speed as the auxiliary drive at all times.
To connect the generator to the grid, the auxiliary drive must speed the generator rotor up to a speed that matches the generator rotating magnetic field. At that point the generator breaker can be closed to connect the generator to the grid. Any additional power input from the auxiliary drive to the is generator will cause power to flow out of the generator to the grid. An alternate method of starting up the generator would be to use the soft start feature supplied with most large scale wind turbines to connect them to the grid. In this case the wind must be used to rotate the propeller, gear, and generator to get it close to the normal operating speed before closing the breaker. In some cases the soft start feature can be used to start the generator from dead stop. In this case, the generator acts as a motor until it gets up to speed at which time the wind energy input causes power to flow out from the generator.
If the auxiliary drive had a torque converter, the operator could start the auxiliary drive and run it up to operating speed before engaging the torque converter to spin up the generator. With the torque converter the engine speed could be changed and the output shaft speed from the torque converter could be held at a constant speed or, conversely, the engine speed could be kept constant and the output speed could be varied along with the generator speed.
The generator can be driven from the wind turbine end, the auxiliary drive end, or both ends at the same time. The generator will not know the difference. It only knows that torque is being applied to its rotor to generate electricity. It would be possible to use the auxiliary drive to reduce the impact of wind gusts on the wind turbine. This could be done by applying a certain amount of power from the auxiliary drive which is over and above the power being supplied to the generator from the wind. In this case the wind turbine would not be supplying full rated power to the generator. When a wind gust hits the wind turbine and increases the generator output and causes high loads on the gearbox, the auxiliary drive would receive a governor signal to reduce its power output so the generator and gear do not experience damaging load increases. Wind turbine manufacturers are constantly working on improvements to minimize the damaging effects of wind gusts and would welcome new solutions to the problem. The current methods to control the effect of wind gusts are associated with the electrical control systems and generators. Variable slip generators are used to help solve the wind gust problem by allowing the generator to temporarily speed up (increased generator slip) to allow the additional wind energy to be converted into kinetic energy and not forcing the energy through the generator. It would be like installing a clutch between the wind turbine propeller shaft and gearbox to allow the clutch to slip during wind gusts to avoid damage to the gears.
iii) Structural Considerations
An additional benefit of the auxiliary drive arrangement is to change the center of gravity of the nacelle. The auxiliary drive acts as a counterweight on the opposite end of the nacelle as the propeller, hub, shaft and gearbox. Due to the extreme weight of those components, the wind turbine nacelle must be positioned to keep its center of gravity above the center of the tower. This means the propeller is positioned quite close to the tower which causes the propeller blades to bend every time they pass by the wind turbine support tower. The wind shadow and flexing of propeller blades has caused fatigue failures of blades in the past. The weight of the auxiliary drive on the opposite end of the nacelle would allow the nacelle to be repositioned so that the propeller blades are farther away from the tower and less susceptible to flexing and fatigue failures.
Reference will now be made to
The second example is similar to the first example except that some of the auxiliary drive components are placed in different relative positions, and an auxiliary drive speed changing section is added in
Components of this second example which are the same as, or similar to, components shown in
All three of these versions of the second example have the following components, the blades 28 b, the hub 30 b, the low speed shaft 32 b, the speed changing section 20 b, the generator section 22 b, and the auxiliary drive section 24 b. In
The first version of the second example of
A third example of the present invention will now be described with reference to
In this third example, the basic system as shown in
In this example the two stages of heat recovery 50 c and 51 c are located in the wind turbine support tower 11 c.
With this system, the heat recovery process captures waste heat from the auxiliary engine 24 c exhaust and the auxiliary engine 24 c coolant. Also, the waste heat is converted into useful electricity using a separate turbine and generator which is part of the heat recovery system located in the tower 11 c.
In this example the auxiliary drive engine coolant is routed from auxiliary drive engine 24 c to an organic rankine cycle boiler 58 c to vaporize the organic working fluid. The cooled engine coolant is then pumped back to engine 24 c using coolant circulation pump 59 c. The rankine cycle involves a boiler feed pump 60 c which pumps the organic working fluid to the boiler 58 c for vaporization. The vapor then flows to the expansion turbine 61 c which is coupled to a generator 62 c. Power from the generator 62 c is connected to the wind turbine electrical switchgear. The vapor then flows out of the expansion turbine 61 c to the air cooled condenser 63 c where it is condensed back into a liquid. The liquid working fluid then flows back to the boiler feed pump 60 c for recirculation.
With the conversion of waste energy into additional electricity, the auxiliary drive 24 c is a very efficient source of additional power for the hybrid wind turbine.
As shown in
There is a solids fuel hopper 90, which directs the solid fuel 92 into a furnace area 94, where there is a forced draft generated by the fan 96. Further, there is a liquid and/or natural gas burner 98, a steam drum 100, a mud drum 102, a boiler flue gas discharge 104, and a bag house 106. There is a steam conduit 108 leading to a steam drive turbine 110. The steam drive turbine 110 is positioned to supply power to the generator 22 d. The steam exhaust from the steam turbine 110 flows along a conduit 112 to an air cooled surface condenser 114 and is cooled by a fan 116. The condensate then flows to the feed water pump 105 and back to the boiler steam drum 100.
A fifth example of the present invention will now be described with reference to
In this fifth example, there is a solar thermal power source in addition to the wind turbine power and also the auxiliary power section. In this case, there would be three sources of power to drive the generator, namely: i) wind; ii) solar generated power; and iii) the auxiliary drive section which, as indicated previously in this text, could be fueled by a wide variety of energy sources, such as an engine driven by diesel fuel, natural gas, ethanol, etc.
The wind and solar energy inputs would produce non-firm energy that cannot be depended upon as a constant source of power. However, the auxiliary drive 24 e (engine or turbine) would be the ultimate backup for firm power generation. Thus, with these three options offered with the wind turbine, the customer could purchase a basic wind turbine, a wind turbine with a solar thermal energy drive, a wind turbine with an engine or turbine (steam, gas turbine, etc.) auxiliary drive, or a wind turbine with both a solar thermal energy drive and an engine or turbine drive. Thus, different sources of energy input to the wind turbine are not mutually exclusive and can cooperate to maximize the output of the wind turbine. With that background information having been given,
Thus, there is the source of firm power in the form of an auxiliary drive engine 24 e or other power source (see
In this example, in
To provide the solar energy,
In operation, either or both of the non firm power sources (i.e., the wind power source and the solar power source) are utilized to provide the energy output to rotate the generator 22 e-1. In the event that either or both of the wind power and solar power are absent because of the surrounding weather environment, and are producing no usable power, or only a smaller output of power, then the auxiliary power source 24 e-1 can be used to supplement the power input to an adequate level. However, if the solar power source and/or the wind power source are adequate, then the auxiliary power section 24 e-1 will not be required.
A sixth example of the present invention will now be described with reference to
In this sixth example, there is an addition of a steam rankine cycle heat recovery system to recover heat from the engine auxiliary drive exhaust. To describe this sixth example, reference is made to
Hot engine exhaust leaving the auxiliary drive exhaust flows to a heat recovery steam generator 144 f where the heat in the exhaust generates steam. The cooled exhaust then flows to the emission control unit 146 f for treatment before it is discharged to atmosphere.
A boiler feed water pump 148 f pumps water to the heat recovery steam generator 144 f to raise steam. The steam and water mixture flows to a steam drum 149 f, which is part of the heat recovery steam generator 144 f, to allow the steam to separate from the mixture and flow to a steam turbine auxiliary drive 25 f. This steam turbine 25 f converts the steam energy into mechanical work by turning the turbine wheel and driving the auxiliary speed changing drive section 26 f and the generator 22 f through overrunning clutches 68 f and 69 f.
After giving up a portion of its energy to the steam turbine 25 f, the steam flows to an air cooled condenser 152 f where it is condensed back into water. The steam condensate then flows through a vacuum deaerator 154 f for oxygen removal before flowing to the boiler feed water pump 148 f which pumps the feed water back to the heat recovery steam generator 144 f to generate more steam.
The addition of the heat recovery system to the engine auxiliary drive increases the overall thermal efficiency of the engine auxiliary drive. Several types of steam drivers can be used to drive the generator. An example of an alternate type of steam drive would be a rotary screw steam drive machine.
A seventh example of the present invention will now be described with reference to
This seventh example comprises a solar thermal energy system which combines the benefits of wind power with solar power using the same turbine structure.
In this example, the entire solar thermal energy system is separated from the wind turbine power generation system. The solar thermal system uses an organic ranking cycle heat recovery system to convert solar energy into electricity.
As shown in
In addition to the cost savings of combining the wind and solar energy to systems in one structure, the solar addition to the wind turbine has the added benefit of providing additional power output during the daylight hours when it is needed most.
An eighth example of the present invention will now be described with reference to
This eighth example comprises a solar thermal energy system and an engine system with heat recovery which combines the benefits of wind power, solar power, and engine power using the same wind turbine support structure.
In the solar thermal system, the solar energy input to a solar absorber 132 h is converted into steam which drives a steam turbine 25 h which is coupled to the wind turbine main generator 22 h. The steam then exits the steam turbine 25 h and flows to an air cooled condenser 152 h where the steam is condensed back into water. The water then flows through a vacuum deaerator 154 h to remove oxygen and then to the feed water circulating pump 148 h where it is pumped back to the solar absorber to generate more steam.
This ninth example of the present invention will now be described with reference to
This ninth example differs from the earlier examples in that the support structure (i.e., the nacelle 13 i) has a nacelle substructure 141 i to provide additional working areas for various purposes, such as to house heat recovery equipment associated with, for example, an auxiliary steam turbine drive.
The existing technology utilizes space in the wind turbine support tower and nacelle to house all equipment necessary to operate a wind turbine. At times it can be a challenge to install all equipment in the allowable space in a cost efficient manner and there is very little room for any extra equipment. Because the nacelle rotates to keep the wind turbine blades facing the wind, any equipment located in the support tower which must cooperate with equipment in the nacelle must address the problem of rotation. This means the design must incorporate flexible joints, cables, hoses and other interconnections that allow the necessary rotation. By installing a nacelle substructure below the nacelle and on the downwind side of the support tower, it is possible to provide a large amount of space to mount equipment which rotates with the nacelle. Thus, the problem of interfacing equipment that does not rotate with equipment that does rotate is eliminated.
Another advantage of nacelle substructures is that it can be shop fabricated and lifted by crane to attach to the underside of the nacelle. Because the nacelle substructure is designed with a width that is no wider than the support tower, there are no detrimental effects to efficient air flow across the tower which would have a negative impact on the wind turbine output. To the contrary, the shape of the nacelle substructure enclosure will act like a tail behind the tower to assist in yaw control.
This ninth example can be advantageous to any of the options described in earlier examples, including a standard wind turbine without any of these options. The substructure could be used with a standard wind turbine to house the electrical gear or other equipment located in the tower to achieve a cost savings during manufacturing. Due to the extremely tall support towers, it is possible to design the height of the substructure such that it extends down the tower as required to house all equipment intended to be located in the tower.
Although an auxiliary engine drive 24 i and steam turbine drive 25 i are shown coupled to the auxiliary gear 26 i, various other configurations shown in other options are equally suited to cooperate with the nacelle substructure. For example, in
The nacelle substructure has the same width as the tower. Thus, the substructure can be extended further down the tower to accommodate additional equipment. There are various options which include the following: i) an engine only configuration in the nacelle; ii)/HRSG/Steam Turbine/Air Cooled Condenser; iii) engine/orc heat recovery/ajr cooled condenser; iv) solar steam generator/steam turbine/air cooled condenser; v) engine/HRSG/solar steam generator/steam turbine/ajr cooled condenser; vi) solar thermal heat absorber (heat transfer fluid)/orc heat recovery/air cooled condenser; vii) engine/solar thermal heat absorber (heat transfer fluid)/orc heat recovery/air cooler.
The nacelle substructure 141 i is attached to the underside of the nacelle such that it rotates with the nacelle. Various pieces of equipment 260 i can be located within the substructure on various levels. Examples are heat recovery equipment 260 i, air cooled condensers 262 i and cooling fans 264 i. As indicated above, the structural supports 272 i for the nacelle substructure are supported by the tower using metal support rings 274 i enable the nacelle with roll around the support rings 274 i when the nacelle rotates to face the wind. Solar thermal absorbers 280 i are located on the support tower itself.
Obviously, the vertical dimension of the nacelle substructure could vary substantially. In the representation of the sub-nacelle in
The nacelle substructure is an elegantly simple method of providing large amounts of space for equipment which rotates along with the nacelle and thereby eliminating the problem of interfacing rotating and non-rotating equipment. The additional weight will also be a counterweight to the wind turbine blades and will allow them to be located further from the tower, thus, reducing the blade flex when the blades pass by the tower.
To summarize at least some of the features of the present invention, the examples of the present invention provide the following advantages: i) the auxiliary drive system will allow a wind turbine to generate firm power rather than non-firm energy; ii) the hybrid wind turbine which incorporates the solar thermal heat recovery system into the wind turbine allows the same generator, switchgear, support tower, real estate, and transmission lines to be used by both the wind turbine and solar thermal power generator; iii) the nacelle sub-structure provides additional space to install equipment that must move with the equipment in the nacelle such as heat recovery steam generators, air coolers, organic rankine cycle heat recovery systems and electrical gear; iv) the nacelle sub-structure enclosure will act as a tail fin on the wind turbine to assist with yaw control; v) the nacelle sub-structure module can be constructed in a shop with ideal working conditions thus improving worker productivity and reducing construction costs; vi) the equipment located in the nacelle sub-structure can be installed in an upright position and remain in an upright position throughout the construction process (equipment located in the support tower must be turned on its side at some point during the shop fabrication, shipment, or construction process); vii) the energy conversion efficiency in BTU/KWH of the hybrid wind turbine which uses wind, and/or solar and/or thermal energy inputs in one combined system is very efficient when compared with the heat rate in BTU/KWH of a thermal energy conversion system alone due to the non-thermal energy inputs from the wind and solar systems; viii) all components of the hybrid wind turbine can be procured and constructed using commercially available equipment and commercially available engineering and construction practices; and ix) the nacelle sub-structure provides an alternate escape route for operations personnel in the event of a fire in the nacelle.
Referring now to
The blades 326 are mounted on a hub 330 that is rotatably supported by the nacelle 324. In particular, the hub 330 may be conventionally is supported by a generator shaft 332 of a generator 334. Accordingly, air movement rotates the blades 326 to cause the generator 334 to generate electricity.
In the example system 320, the generator shaft 332 is in turn connected to a gearbox 336 through a first overrunning clutch 338. The gearbox 336 is connected to a variable speed drive 340 through a second overrunning clutch 342. The variable speed drive 340 is connected to an auxiliary drive engine 344 through a coupling 346. The auxiliary drive engine 344 is connected to a fuel line 348 connected to a conventional fuel source (not shown) such as fuel storage tanks or utility fuel lines. The fuel line 348 depicted in
Accordingly, when desired, the auxiliary drive engine 344 may be operated to rotate the generator shaft 332 through the coupling 346, variable speed drive 340, second overrunning clutch 342, gearbox 336, and first overrunning clutch 338. Operation of the auxiliary drive engine 344 thus causes the generator 334 to generate electricity.
As with others of the example systems described above, the auxiliary drive engine 344 of the example system 320 is located in the top portion 350 of the system 320. In the example system 320, the top portion 350 containing the auxiliary drive engine 344 is located below the nacelle 324 within an upper end of the tower structure 322.
An exhaust line 352 connects the auxiliary drive engine 344 to a heat to recovery system 354 located at a lower portion 356 of the system 320. Again, the exhaust line 352 depicted in
The example configuration depicted in
Referring now to
The blades 426 are mounted on a hub 430 that is rotatably supported by the nacelle 424. In particular, the hub 430 may be conventionally supported by a generator shaft 432 of a generator 434. Accordingly, air movement rotates the blades 426 to cause the generator 434 to generate electricity.
In the example system 420, the generator shaft 432 is in turn connected to a gearbox 436. In this example system 420, the blades 426 are located on an opposite end of the nacelle 424 from the generator 434, and the gearbox 436 is arranged between the blades 426 and the generator 434. An overrunning clutch 438 may be connected between the hub 430 and the gear box 436.
The gearbox 436 is connected to a fluid drive reduction gear 440 through an overrunning clutch 442. The fluid drive reduction gear 440 is connected to an auxiliary drive engine 444 through a coupling 446. The auxiliary drive engine 444 is connected to a fuel line 448 connected to a conventional fuel source (not shown) such as fuel storage tanks or utility fuel lines. The fuel line 448 depicted in
Accordingly, when desired, the auxiliary drive engine 444 may be operated to rotate the generator shaft 432 through the coupling 446, fluid drive reduction gear 440, overrunning clutch 442, and gearbox 436. Operation of the auxiliary drive engine 444 thus causes the generator 434 to generate electricity.
As with others of the example systems described above, the auxiliary drive engine 444 of the example system 420 is located in the top portion 450 of the system 420. In the example system 420, the top portion 450 containing the auxiliary drive engine 444 is located below the nacelle 424 within an upper end of the tower structure 422.
An exhaust line 452 connects the auxiliary drive engine 444 to a heat recovery system 454 located at a lower portion 456 of the system 420. Again, the exhaust line 452 depicted in
Accordingly, in the example system shown in
Although not shown in
Referring now to
The blades 526 are mounted on a hub 530 that is rotatably supported by the nacelle 524. In particular, the hub 530 may be conventionally supported by a generator shaft 532 of a generator 534. Accordingly, air movement rotates the blades 526 to cause the generator 534 to generate electricity.
In the example system 520, the generator shaft 532 is in turn connected to a gearbox 536 through a first overrunning clutch 538. The gearbox 536 is connected to a variable speed drive 540 through a second overrunning clutch 542. The variable speed drive 540 is connected to an auxiliary drive engine 544 through a coupling 546. The auxiliary drive engine 544 is connected to a fuel line 548 connected to a conventional fuel source (not shown) such as fuel storage tanks or utility fuel lines. The fuel line 548 depicted in
Accordingly, when desired, the auxiliary drive engine 544 may be operated to rotate the generator shaft 532 through the coupling 546, variable speed drive 540, second overrunning clutch 542, gearbox 536, and first overrunning clutch 538. Operation of the auxiliary drive engine 544 thus causes the generator 534 to generate electricity.
As with others of the example systems described above, the auxiliary drive engine 544 of the example system 520 is located in the top portion 550 of the system 520. In the example system 520, the top portion 550 containing the auxiliary drive engine 544 is located below the nacelle 524 within an upper end of the tower structure 522.
An exhaust line 552 connects the auxiliary drive engine 544 to a heat recovery system 554 located at a lower portion 556 of the system 520. Again, the exhaust line 552 depicted in
The example configuration depicted in
As will be explained in further detail below, the example wind turbine system 520 further comprises a solar absorber system 560. The solar absorber system 560 is secured at a desired elevation relative to the tower structure 522; a solar heat line 562 carries heated fluid from the solar absorber system 560 to the heat recovery system 554 as will be described in further detail below.
The drawings further illustrate an absorber housing 566 and a layer of heat absorption material 568 on or forming a part of the housing 566. The heat absorption material 568 has desirable heat transfer properties and typically will be, or be coated with, a color, such as black, that facilitates the absorption of heat.
As is conventional, wind imparts energy to the wind turbine blades 526 which move the blades 526 and blade hub 530. The blade hub is connected to a shaft 532 which turns the generator 534. The example generator 534 used in this embodiment is preferably, but not necessarily, capable of operating at a very low speed to obviate the need for a speed reduction gear to allow the generator to be connected to the generator shaft 532. The example generator 534 is an AC permanent magnet generator that can operate at various rotational speeds and produces alternating current which may or not be at a standard frequency of 50 or 60 cycles per second. To correct for this possible deviation from the desired frequency, the output of the generator 534 is converted to direct current and subsequently rectified back to 50 or 60 cycle AC current. By allowing the generator 534 to operate at various speeds, wind turbine efficiency can be optimized for various wind speeds.
Referring now to
A combustion air fan 648 draws ambient combustion air through an opening 646 in the tower structure 522 and sends it to the solar absorber burner 640. The burner 640 combusts gas or liquid fuel 642 with engine exhaust 612, combustion air, or a mixture of engine exhaust 612 and combustion air. The flue gas from the burner 640 flows upward in the annular space 656 between the absorber tubes 630 and tower wall insulation 638 and transfers heat to the absorber tubes 630. The combination of solar energy directed onto the outside of the solar absorber tubes 630, waste heat carried by the exhaust 612, and heat from combusting the supplemental fuel 642 directed to the inside of the solar absorber tubes 630 allows the solar absorber 610 to supply thermal energy continuously, if desired, during daytime or night time hours. This design feature allows the solar absorber 610 to be classified as a hybrid solar absorber.
A heat transfer fluid is pumped through heat transfer fluid inlets 632 in the solar absorber tubes 630 to absorb heat from the solar and thermal energy sources. The hot heat transfer fluid flows out of outlets 634 in tubes 630 forming the solar absorber 610 to an organic rankine cycle heat recovery system turbine/generator or a conventional rankine cycle system turbine/generator to convert the thermal energy into electrical energy. Components of the Rankine cycle other than the solar absorption tubes 630, engine exhaust heat exchanger 620, and emission control device 670, combustion air fan 648, associated dampers and controls, and burner 640 can be located, if desired, at ground level at the base of the tower structure 522 as described herein. Thermal insulation 638 is applied to the outside of the wind turbine tower structure 522 to prevent overheating due to a mis-directed solar reflector which normally directs the solar rays onto the solar absorber tubes 630.
A tower manway 658 allows access to the solar absorber access duct 656. The solar absorber access duct also allows access to the fin-fan air coolers 662 which are mounted on the wall of the solar absorber access duct to 656. The fin-fan air coolers 662 reject waste heat from the rankine cycle heat transfer fluid to condense the fluid from the vapor state to the liquid state. The fin-fan coolers 662 can also be mounted on the ground at the base of the tower structure 522, if desired. The tower manway 658 also allows access to the solar absorber tubes 630. A tower manway 664 and platform 666 allow access to the burners 640 for maintenance.
Referring now to
The example energy recovery system 554 depicted in
If the engine 544 is not operating, the solar absorber can still receive supplemental heat by operating the combustion air fan 648 to provide oxygen for combustion of the supplemental fuel 642. If the engine 544 is not operating and it is necessary to operate the combustion air fan, damper 650 is closed and damper 652 is opened to prevent combustion air from flowing through the ductwork backward toward the engine 544. If the engine 544 is running and it is not necessary or desired to operate the combustion air fan 648, the damper 652 will be in the closed position and damper 650 will be in the open position. After passing through the solar absorber 612, the exhaust flue gas 654 is vented to atmosphere.
A pump 722 is used to circulate the heat transfer fluid through the solar absorber and engine exhaust heat exchanger 720. The fluid then flows to the organic rankine cycle boiler 724 where it vaporizes the working fluid. The heat transfer fluid then flows back to the circulating pump 722 to be re-circulated through the system again.
A pump 730 is used to pump an organic rankine cycle working fluid such as isopentane to the boiler 724 where it is vaporized. The vapor then flows to the organic rankine cycle turbine 732 where it expands and turns a shaft 734 which is connected to a generator 736 using coupling 738. The vapor passes through the turbine 732 and flows to an air cooled condenser 740 which condenses the vapor into a liquid. The liquid flows back to the circulating pump 730 where it is pumped back to the boiler 724.
Referring now to
The heat recovery system 554 utilizes a steam rankine cycle heat recovery system. As generally discussed above, the system 520 utilizes the wind to turn the generator 534 to produce electricity, solar energy from the sun to produce electricity using an steam rankine cycle and an engine 544 to generate supplemental or emergency power using conventional fossil fuels. The hot flue gas from the engine 544 flows through a heat exchanger 750 where it transfers heat to a circulating heat transfer fluid. The flue gas then passes through an emission control device 670 and then to a burner 640 before entering the solar absorber 612 where it passes by and transfers heat to the solar absorber tubes 630.
Additional heat may be added to the engine 544 exhaust flue gas by utilizing the burner 640 to burn additional fuel 642. The flue gas contains sufficient oxygen to allow combustion of the supplemental fuel 642. If the engine 544 is not operating, the solar absorber 610 can still receive supplemental heat by operating the combustion air fan 648 to provide oxygen for combustion of the supplemental fuel 642. If the engine 544 is not operating and it is necessary to operate the combustion air fan, damper 650 is closed and damper 652 is opened to prevent combustion air from flowing through the ductwork backward toward the engine 544. If the engine 544 is running and it is not necessary or desired to operate the combustion air fan 648, the damper 650 will be in the open position and damper 652 will be in the closed position. After passing through the solar absorber 610, the exhaust flue gas 654 is vented to atmosphere.
The steam rankine cycle in
Feedwater that is pumped to the engine exhaust boiler 750 is converted into steam and then flows to a steam drum 756 for separation into steam and water. The steam flows out of the steam drum 756 to the steam turbine 760 where it turns the turbine rotor and drives the generator 764 through coupling 766 to generate electricity. Low pressure steam exits the steam turbine 760 and flows to a surface condenser 768 where it is condensed back to water and then flows to the feedwater pump 752 for recirculation. Water that is separated out in the steam drum 756 flows to a deaerator 758 and back to the boiler feedwater pump 752.
While the present invention is illustrated by description of several examples and while the illustrative examples are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants' general concept.