SOLAR SORPTION REFRIGERATORS WITH DUAL SOURCES OF ENERGY L.L.Vasiliev SOLAR SORPTION REFRIGERATORS WITH DUAL SOURCES OF ENERGY Luikov Heat & Mass Transfer Institute, Minsk, Belarus

INTRODUCTION Refrigeration is critical in the food production and distribution Developing countries extremely need for refrigeration, and air- conditioning in regions free of grid electricity Concept of Solar-powered Refrigeration adsorption cycles (day/night) Solar Short Time Cycles sorption machines as alternative to day/night Concept of combined action of Physical Adsorption and Chemical Reactions Concept of complex compound Two Stage Resorption systems Heat Pipes for adsorption refrigerators performance improvement and thermal control Adsorbed Natural Gas storage as an additional/alternative source of energy

RESEARCH PURPOSES WERE TO DESIGN A REFRIGERATIR, which: would operate without grid electricity; consuming a cheap energy (solar energy concentrator and autonomous, low pressure adsorbed natural gas storage system); can be built and maintained in the country of use; be light and portable; be low enough in cost.

SOLID SORPTION REFRIGERATOR MAIN DESIGN HIGH TEMPERATURE PART LOW TEMPERATURE PART WATER LOOP THERMAL CONTROL SYSTEM AMMONIA REFRIGERATOR

SOLID SORPTION REFRIGERATOR VIEW and CHRACTERISTICS 1 – Evaporator 2 – Adsorber No.1 3 – Adsorber No.2 General view

SORBENT BED – “Busofit” Dubinin-Astakhov XBusofit -055 = 11, 7 Å Adsorption/desorption isotherms

SORBENT BED – “Busofit” Dubinin-Radushkevich Wo=0,491 B=8,56*10-6 - experiment Full sorption capacity, kg/kg of the sorbent Busofit + CaCl2 Acetone 0.61   Ammonia 0.62 0.85 Ethanol 0.6 Methanol 0.55 Adsorption isotherms

SORBENT BED – COMPLEX COMPAUND “Busofit” “Busofit” + CaCl2

SORBENT BED – COMPLEX COMPAUND Diagrams of the thermodynamic equilibrium Adsorption isotherms CaCl2 + nNH3  CaCl2 (NH3)n + n H

SOLAR-GAS REFRIGERATOR MAIN PARAMETERS Solar-gas reactor L = 1.2; D = 0.05 m “Busofit” mass in the reactor 0.75 kg CaCl2 in one reactor 0.32 kg Ammonia mass in one reactor 0.92 kg Water mass in one reactor 1 kg Ammonia mass in the pulsating HP 0.05 kg Total mass of the refrigerator 22 kg Temperature of the hot reactor surface 120 0C Condenser temperature 50 0C Cabinet evaporator temperature (without heat pipes) -18 0C Heating capacity (W/kg sorbent) 850

SOLAR REFRIGERATOR HIGH TEMPERATURE PART

SOLAR REFRIGERATOR LOW TEMPERATURE PART - Condenser Element of Condenser Heat transfer coefficient in the Condenser

SOLAR REFRIGERATOR LOW TEMPERATURE PART - Evaporator Evaporator design Heat transfer coefficient in the Evaporator

SOLAR REFRIGERATOR LOW TEMPERATURE PART – Loop heat pipe Loop Heat Pipe design Temperature Deviation of 2 Loop Heat Pipes

LOW TEMPERATURE PART – Parameters SOLAR REFRIGERATOR LOW TEMPERATURE PART – Parameters Adsorber dimensions, m L = 1.2 ;D = 0.05 “Busofit” mass 0.75 kg Ammonia mass 0.3 kg Thermpsyphon water mass 0.6 kg Refrigerator cabinet volume 0.2 m3 Cabinet Temperature 0 0C – 10 0C Ammonia mass in HP 0.05 kg Cold output (cabinet) 150 -300 W Clapeyron diagram for the complex compound“Busofit” + CaCl2 and ammonia in the refrigeration cycle Heat output (condenser) 300-500 W HP surface inside the cabinet 1.2 m2 The time of the cycle 15 min

CONCLUSIONS A solar gas/electrical solid sorption refrigerator with 1.8 m2 collection surfaces was designed and studied. The ratio between solar energy and gas, or electrical energy supply is automatically maintained on the level of 1 kW. The COPR of the refrigerator is near 0.44. The combination an active carbon fiber “Busofit” + chemicals in one reactor with the porous condenser/evaporator is very promising for the designing of the portable and light autonomous cooler for ground, space and hazardous applications.