Non-tracking Solar Cooling with 61/2 RT Absorption Chiller Reference 0119 Solar Cooling

In the summer of 2011 a new technology was demonstrated for the first time in a real world setting: an external compound parabolic concentrator powering a double effect absorption chiller. The collector configuration is an evacuated tube receiver matched to an external non-imaging reflector, typically referred to as an XCPC. The XCPC provides solar concentration without moving parts that can achieve operating temperatures up to 200°C. The design principle maximizes the probability that radiation starting at the receiver would be directed to a specific band in the sky we wish to accept. In our case “north-south orientation’’ this band is 120 degrees in azimuth and 180 degrees in elevation. This corresponds to a nominal operational time period of eight hours a day with a concentration ratio of 1.18.A commercial double-effect hybrid gas-fired chiller was run on solar energy operating at temperatures between 150-180°C. Daily solar collector efficiencies, coefficient of performance and system characterization are presented in this paper. It is shown that the double effect absorption chiller can operate with fixed solar thermal collectors effectively.

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Schools of Natural Science and Engineering, University of California Merced

Director, California Advanced Solar Technologies Institute (UC Solar)

rwinston@ucmerced.edu http://ucsolar.org

WREF 2012 Denver, CO 5/17/2012

Roland Winston , Heather Poiry, Kevin Balkosky, Lun Jiang

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Characteristics of an optimal concentrator design

• Let Source be maintained at T1 (sun)

• Then T3 will reach T1 ↔ P31 = 1

• Proof: q13=sT14A1P13 = sT1

4A3P31

• But q3total=sT34A3 ≥ q13 at steady state

• T3 ≤ T1 (second law)→P31=1 ↔ T3=T1

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radiation

source 2

aperture

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absorber

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How?

• Non-imaging optics:

– External Compound Parabolic Concentrator (XCPC)

– Non-tracking

– Thermodynamically efficient

– Collects diffuse sunlight

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Highlight Project—Solar Thermal

• UC Merced has developed the External Compound Parabolic Concentrator (XCPC)

• XCPC features include:

– Non-tracking design

– 50% thermal efficiency at 200°C

– Installation flexibility

– Performs well in hazy conditions

• Displaces natural gas consumption and reduces emissions

• Targets commercial applications such as double-effect absorption cooling, boiler preheating, dehydration, sterilization, desalination and steam extraction

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Testing

• Efficiency (80 to 200 °C)

• Optical Efficiency (Ambient temperature)

• Acceptance Angle

• Time Constant

• Stagnation Test

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Acceptance Angle

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Comparison

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Power Output of the Solar Cooling System

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Delivering BTUs from the Sun

10kW test loop NASA/AMES

10kW Array Gas Technology Institute

Conceptual Testing SolFocus & UC Merced

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Hospital in India

Roland, I hope Shanghai went well Hit 200C yesterday with just 330W DNI. Gary D. Conley~Ancora Imparo

www.b2uSolar.com

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