US20070034205A1

US20070034205A1 - Solar parabolic trough, receiver, tracker and drive system

Info

Publication number: US20070034205A1
Application number: US11/500,797
Authority: US
Inventors: Phillip Watts
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-08-15
Filing date: 2006-08-08
Publication date: 2007-02-15

Abstract

This invention integrates the receiver as a support with improved performance and rigidity and eliminates moving fluidic components that increase the units overall reliability and lowers construction costs. The cable drive mount system provides foul weather operation coupled with a slip clutch for un anticipated loads. Integrating the sun tracker into the parabolic trough body eliminates the need for timing and calibration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Provisional Patent 60/708172 Aug. 15, 2005

STATEMENT REGARDING FEDERALLY SPONORED RESEARCH OR DEVELOPMENT

Not applicable

REFERENCE TO A MICROFICHE APPENDIX

Not applicable

BACKGROUND OF THE INVENTION

Cost Reduced total System through Component Integration and Stationary Fluidic Hoses

BRIEF SUMMARY OF THE INVENTION

The apparatus as depicted in FIG. 1.0 integrates the receiver tube as a support for the parabolic trough and by bifurcating the fluid path in the receiver tube, the fluidic hoses remain fixed with no movement which reduces cost. Maintenance is minimized by stationary hoses. The drive mechanism is weight reduced by drum and cable integrated around the receiver which gives the unit freeze protection and/or high temperature protection at low cost. The sun tracking electronics split the sun's radiation with a fixed nose between the optical sensors just as the human nose between the eyes does. This feature removes calibration and maintenance. The parabolic mirror is of silver on Mylar which reduces initial cost and is repaired via a band-aid concept reducing initial cost and maintenance costs.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1. Solar Trough Assembly with integrated receiver mount and motor drive. FIG. 1. depicts a view of the trough built of a parabolic shaped aluminum with reflective silver membrane bonded to metal or plastic. The low cost and light weight Parabolic trough body rotates around the outside of the receiver tube tracking the sun and focusing the suns rays on to a selective coating on the receiver tube. This implementation supports polar mounting or east-west or north-south mountings. In the polar mount the receiver tube will receive 20 percent more solar insolation than in the conventional east-west or north-south mountings during the spring and summer months.
FIG. 2. Depicts the motor, drum and cable that drive the Parabolic Trough around the receiver tube. The cable is wrapped around the drum, which is attached to the trough body. The motor is attached to the receiver tube.
FIG. 3. Depicts the receiver tube construction details. Incoming fluids are routed around the center tube in a spiral motion to lengthen the fluids time to transverse the length of the bifurcated receiver tube where the fluid is returned inside the center tube and exits the stationary end of the receiver tube.

DETAILED DESCRIPTION OF THE INVENTION

This application integrates multiple components; tracker, motor drive, receiver and trough body that makeup the mirror and its support of a Solar Parabolic Trough into one entity to reduce costs and increase performance. Performance is increased by configuring the fluid path with a helix spiral that effectively triples the receiver tubes length of time to receive energy while reducing the actual receiver length by two thirds.
Refer to FIG. 1 for the following description. Incoming heat transfer medium enters at number 1 to be heated. As the heated fluid is guided by number 3, the spiral looping path around the exit tube labeled as number 2, effectively increases the length of travel for the heat transfer medium which increases time to absorb more energy than a straight pipe. At the end of the receiver tube labeled as 4, the heat transfer medium is channeled into the center of the pipe for a direct and shorter time to exit once the heat transfer medium is heated. The bifurcated channel that has a longer time to transverse and a shorter time to return is the major performance improvement of the receiver tube. The construction of an inner tube number 2 with a rigid standoff number 3 and finally encased with an outer tube number 5 makes for a more rigid receiver tube that can be used as its own support and less sag so as to maintain optical alignment with the trough body that rotates around the receiver tube. The outer tube number 5 is mounted rigidly so no fluid path tubes require movement and eliminates swivel fluid joints.
Refer to FIG. 2 for the following description. The motor drive assembly is mounted to the parabolic trough body by attaching to the receiver tube number 1. The drum number Sis bolted to the body of the trough frame by number 6 holes in the drum number 5. A bearing surface number 7 is dimensioned to fit the receiver tube number 1. For high temperature operation an insert can be fitted at number 7. The motor mount block 4 is securely mounted to the receiver tube number 1. When the tracker provides bi-directional movement to the motor, the motor's drum number3 imparts motion to the cable number2 that is wrapped around the drum number 5. The drum number 5 floats of a bearing surface around the receiver tube number 1. Motion to the trough body that is bolted to the drum number 5, via the two bolts number 6. This embodiment of the apparatus allows for slippage on the motor drum number 3 when overloading should occur. No timing or alignment is required as the system is self recovering. Heating for the motor for cold weather conditions is accomplished by scaling number 5 to conduct via cross-sectional area of number 5. High temperature operation is accommodated by using an insulating material for number 5. By mounting the sun tracker to the trough body alignment is maintained on the receiver tube number 1.

Claims

1. Heat transfer is increased to the fixed receiver tube with it's stationary fluid connections by sweeping the trough's concentrated line of light focus around the exterior of the receiver tube every ⅓ of a second with a rocking-chair action, which effectively increases the cross-sectional area for heat transfer;

2. The receiver tube with a spiral fluid path increases the length of travel through the bifurcated receiver tube which increases the dwell time for the fluid to absorb heat and the short center tube rushes the heated fluid in as shortest time out of the receiver tube;

3. By attaching the motor or the motor drive system to the receiver tube, the motor can be heated for cold weather operation and isolated for extremely hot fluid operation via an insulating ring, and where by the apparatus with integrated drive cable, capstan or motor eliminates timing and calibration issues as the unit is self recovering and has a slip clutch mechanism to protect against unexpected loads.