[001] CLOSED LOOP SINGLE AXIS GANGED TRACKING ASSEMBLY
[002] FIELD OF THE INVENTION
[003] Embodiments of the present invention in general relate to a ganged
tracking assembly, and in particular relates to a closed loop single axis
ganged tracking assembly with feedback for a linear fresnel reflector solar
energy collector system.
[003] BACKGROUND
[004] Solar power generation has been considered a viable source to help
provide for energy needs in a time of increasing consciousness of the
environmental aspects of power production. Solar energy production relies
mainly on the ability to collect and convert energy freely available from the
sun and can be produced with very little impact on the environment. Solar
power can be produced without creating radioactive waste as in nuclear
power production, and without producing pollutant emissions including
greenhouse gases as in fossil fuel power production. Solar power
production is independent of fluctuating fuel costs and does not consume
non-renewable resources.
[005] Solar power generators generally employ fields of controlled mirrors,
to gather and concentrate sunlight on a receiver to provide a heat source
for power production. A solar receiver typically takes the form of a panel of
tubes conveying a working fluid therethrough. Previous solar generators
[ have used working fluids such as molten salt because it has the ability to
store energy, allowing power generation when there is little or no solar
radiation, such as at night time. The heated working fluids are typically
conveyed to a heat exchanger where they release heat into a second
working fluid such as air, water, or steam. Power is generated by driving
heated air or steam through a turbine that drives an electrical generator.
[006] Such conventional methods and systems for solar power generation
have generally been considered satisfactory for their intended purpose.
However, there is still a need in the art for systems and methods for solar
power generation that allow for improved efficiency and decreased heat
loss.
[007] SUMMARY
[008] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes one or more
primary reflectors wherein the one or more primary reflectors which are
arranged in parallel to each other.
[009] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes one or more
primary reflectors which are arranged in parallel to each other, and further
( the one or more primary reflectors are laterally connected to each other by
at least a connecting arm and tracking arm of a ganged tracking assembly.
[010] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes one or more
primary reflectors that are preset with respect to each other at pre-defined/
preset tilt angles, and wherein the pre-defined/ preset angles are driven by
a combination of at least one gear box and at least one motor.
[011] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes a ganged tracking
assembly which is connected to a feedback circuit including an electronic
controller wherein the electronic controller receives a feedback signal from
one or more sensors attached to the one or more primary reflectors and at
least one receiver.
[012] According to an embodiment of the present invention there is a direct
saturated and superheated steam generating linear fresnel reflector solar
energy boiler system that includes one or more primary reflectors and a
ganged tracking assembly. The ganged tracking assembly along with an
electronic controller and one or more sensors operate in a closed loop, and
maximizes an optical efficiency during operation.
[013] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
H
fresnel reflector solar energy boiler that Includes one or more primary
reflectors that are mounted on one or more axles wherein the one or more
axles rest on one or more rollers that facilitates and supports axial rotation.
[014] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes one or more
primary reflectors that are mounted on one or more axles. Each of the one
or more axles includes axle plates and wherein the axle plates of each of
the one or more axles are configured to accommodate a tracking arm for
each row of the one or more primary reflectors. The tracking arms for each
row of the one or more primary reflectors further have a slot provision
around the axle for setting the tilt angle for each row of the one or more
primary reflectors.
[015] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes at least one linear
cavity receiver housing a single evacuated tube collector and one or more
primary reflectors, wherein the one or more primary reflectors concentrates
the sunlight on to an ETC and thereby increasing the concentration ratio.
[016] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system wherein an ETC is clamped
such that the position of the ETC is fixed in the cross sectional plane and
allowed to expand due to thermal expansion in a longitudinal direction
along the length of the ETC.
[017] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system for generating useful heat in the
form of saturated or/and superheated steam by concentrating sunlight on to
a single row of one or more evacuated receiver tube collectors housed
along with one or more primary reflectors inside a receiver support
structure.
[018] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system wherein the sunlight is focused
continuously by the one or more primary reflectors on to the one or more
evacuated collector tubes. Further, the one or more primary reflectors are
placed close to the ground which tracks the sun by a mechanical system
connected to the electronic controller which receives feedback signal from
the one or more sensors attached to the one or more primary reflectors and
one or more receivers.
[019] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes a ganged tracking
assembly that helps to decrease the errors and the cost per module as the
{ number of one or more reflectors and the area covered by the ganged
tracking assembly is higher compared to the previous configuration.
[020] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes a configuration
having a single row of evacuated receiver tube collectors and one or more
secondary reflectors that increases the concentration ratio (Total mirror
aperture width to absorber tube aperture width) and hence the operation
parameters (Temperature and pressure of steam).
[021] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes an absorber tube
that is maintained in vacuum during operation hence the heat loss is
reduced and the efficiency is increased considerably.
[022] According to an embodiment of the present invention there is
provided a direct saturated and superheated steam generating linear
fresnel reflector solar energy boiler system that includes a single row of
evacuated receiver tube collector configuration that simplifies the process
line and instrumentation thereby reducing the cost and operation
procedure.
[023] These and further aspects which will be apparent to the expert of the
art are attained by a direct saturated and superheated steam generating
linear fresnel reflector solar energy boiler system in accordance with the
7
main claim.
[024] BRIEF DESCRIPTION OF THE DRAWINGS
[025] So that the manner in which the above recited features of the present
invention can be understood in detail, a more particular description of the
invention, briefly summarized above, may be had by reference to
embodiments, some of which are illustrated in the appended drawings. It is
to be noted, however, that the appended drawings illustrate only typical
embodiments of this invention and are therefore not to be considered
limiting of its scope, for the invention may admit to other equally effective
embodiments.
[026] Figure 1 illustrates a perspective view of a Linear Fresnel Reflector
(LFR) system according to an embodiment of the present invention;
[027] Figure 2 illustrates a perspective view of a ganged tracked assembly
of a Linear Fresnel Reflector (LFR) system according to an embodiment of
the present invention;
[028] Figure 3 illustrates a sectional view of the ganged tracked assembly
of the Linear Fresnel Reflector (LFR) system of the Figure 2 according to
an embodiment of the present invention;
8
[029] Figure 4 illustrates a flow chart of an operation of a Linear Fresnel
Reflector (LFR) system according to an embodiment of the present
invention; and
[030] Figure 5 illustrates a perspective view of a microcontroller in a Linear
Fresnel Reflector (LFR) system according to an embodiment of the present
invention.
[031] To facilitate understanding, identical reference numerals have been
used, where possible, to designate identical elements that are common to
the figures. It is to be noted, however, that the appended drawings illustrate
only typical embodiments of this invention and are therefore not to be
considered limiting of its scope, for the invention may admit to other equally
effective embodiments.
[032] DETAILED DESCRIPTION OF THE DRAWINGS
[033] Figure 1 to 5 illustrates various views of a Linear Fresnel Reflector
(LFR) system according to an embodiment of the present invention. The
Linear Fresnel Reflector (LFR) based concentrated solar thermal system
100 includes a linear cavity receiver 102 housing one or more secondary
reflectors 104 and evacuated absorber tube collector (single tube collector)
106, one or more primary reflectors 108 , a ganged tracking assembly, and
one or more closed loop feedback sensors for controlling the ganged
tracking assembly.
1
I [034] In an embodiment, the one or more primary reflectors 108 are
arranged in parallel with respect to each other, and each of the one or more
primary reflectors 108 are placed at a proximate distance (a gap) with
respect to the ground. The gap is so chosen that the shadow of the one or
more primary reflectors 108 is not casted on adjacent primary reflectors of
the one or more primary reflectors 108 at least for a particular hour angle.
[035] The one or more primary reflectors 108 are mounted on
corresponding one or more axles 301. The one or more axles 301 rest on
corresponding one or more rollers 300 for supporting axial rotation. The
one or more rollers 300 are coupled laterally using a steel hollow section
(connecting arm) 303 and connected by one or more levers (tracking arm)
305.
[036] In an embodiment, each of the one or more axles 301 comprises an
axle plate which is configured to accommodate the corresponding one or
more tracking arms 305 for each row of the one or more primary reflectors
108. The axle plates are configured to rest on a roller v-block and further
clamped from its top portion with another set to aid rotation and support
during upward loads due to wind.
[037] In an embodiment, each of the one or more tracking arms 305 further
includes a provision for a slot around each axle of the one or more axles
301 for setting the tilt angle for each row of the one or more primary
reflectors 108. According to one embodiment of the present invention, the
angle of tilt for each primary reflector of the one or more primary reflectors
fo
108 is preset and fixed. The one or more primary reflectors 108 is then
driven laterally by a single motor connected to a gear box 304 and thus
reducing the power consumption and cost. In an embodiment the motor is a
stepper motor but in any other embodiment of the present invention any
motor may be used without moving out of the scope of the disclosed
embodiments.
[038] Further, a tilt sensor attached to one of the primary reflectors of the
one or more primary reflectors 108 is used to set the connected set from
the one or more primary reflectors 108 to the required angle. Thereafter,
the signals from the tilt sensor are feed to an electronic controller which in
turn sets the stepper motor in to motion.
[039] In an embodiment, an array of sensors (photodiodes) 306 is
provided. One of the ends of the array of sensors (photodioides) 306 are
connected to a glass optic fiber cable array 307 and the other ends of the
array of sensors (photodiodes) 306 are laid across the cross section of the
receiver to send feedback signals to the microcontroller. Based on the
feedback from the microcontroller, the intensity of sunlight distribution
across the ETC is qualitatively measured by the PLC, and subsequently the
stepper motor is adjusted for maximum output.
[040] In an embodiment of the present invention the ganged tracking
system depicted in above figures facilitates the decrease in the errors and
the cost per module as the number of the plurality of primary reflectors 108
and an area covered by the one mechanical tracking system is higher
compared to the previous configuration. Further, Linear Cavity receiver
structure houses the secondary reflector and the evacuated absorber tube
collector and is fixed at an optimum height from the secondary reflector.
Also, the Linear Cavity receiver is stationary and is internally provided with
a mechanism for allowing thermal expansion of the ETC.
[041] While the foregoing is directed to embodiments of the present
invention, other and further embodiments of the invention may be devised
without departing from the basic scope thereof, and the scope thereof is
determined by the claims that follow.

We Claim
1. A linear fresnel reflector solar energy boiler system comprising:
one or more primary reflectors, wherein the one or more
primary reflectors are arranged in parallel to each other;
a ganged tracking assembly, wherein the ganged tracking
assembly comprises at least a connecting arm and a tracking
arm, and wherein the ganged tracking assembly facilitates
adjustment of tilt angles of the one or more primary reflectors;
and
at least one gear box and motor; and wherein the one or
more primary reflectors are preset with respect to each other
at pre-defined tilt angles, and wherein the pre-defined tilt
angles are driven by a combination of the at least one gear
box and the at least one motor.
2. The linear fresnel reflector solar energy boiler system of claim 1
comprises the one or more primary reflectors that are laterally
connected to each other by the connecting arm and the tracking arm
of the ganged tracking assembly.
3. The linear fresnel reflector solar energy boiler system of claim 1
comprises one or more sensors attached to the one or more
reflectors and at least one receiver.

4. The linear fresnel reflector solar energy boiler system of claim 3,
wherein the ganged tracking assembly is connected to a feedback
circuit comprising an electronic controller, and wherein the electronic
controller receives a feedback signal from the one or more sensors
attached to the one or more reflectors and the at least one receiver.
5. The linear fresnel reflector solar energy boiler system of claim 4,
wherein the ganged tracking assembly along with the electronic
controller and the one or more sensors operate in a closed loop.
6. The linear fresnel reflector solar energy boiler system of claim 1,
wherein the one or more primary reflectors that are mounted on one
or more axles.
7. The linear fresnel reflector solar energy boiler system of claim 6,
wherein the one or more axles rest on one or more rollers that
facilitates and supports axial rotation.
8. The linear fresnel reflector solar energy boiler system of claim 7,
wherein each of the one or more axles comprises axle plates, and
wherein the axle plates of each of the one or more axles are
configured to accommodate a tracking arm for each row of the one
or more primary reflectors.
9. The linear fresnel reflector solar energy boiler system of claim 1,
wherein the tracking arms for each row of the one or more primary
reflectors has a slot provision around each axle of one or more
\H
U t:^ ^ ^
corresponding axles for setting the tilt angle for each row of the one
or more primary reflectors.
10. The linear fresnel reflector solar energy boiler system of claim 3,
wherein the feedback circuit operates based on measurement of
solar intensity distribution across the at least one receiver.
11. The linear fresnel reflector solar energy boiler system of claim 10,
wherein the feedback circuit is isolated from a hot receiver zone
using a glass fiber optic cable.