Experimental study on a resorption system for power and refrigeration cogeneration

Abstract

Energy conversion technologies, especially for power generation and refrigeration technologies driven by the low temperature heat, are gathering the momentum recently. This paper presents a novel resorption system for electricity and refrigeration cogeneration. Compared with adsorption refrigeration system, resorption refrigeration is characterized as safety and simple structure since there is no ammonia liquid in the system. The cogeneration system is mainly composed of three high temperature salt (HTS) unit beds; three low temperature salts (LTS) unit beds, one expander, three ammonia valves, two oil valves, four water valves and connection pipes. Chemical working pair of MnCl 2 -CaCl 2 -NH 3 is selected. Since scroll expander is suitable for small type power generation system, it is chosen for expansion process. 4.8 kg MnCl 2 and 3.9 kg CaCl 2 impregnated in expanded natural graphite treated with sulfuric acid (ENG-TSA) are filled in the cogeneration system. Experimental results show that maximum cooling power 2.98 kW is able to be obtained while maximum shaft power is about 253 W with 82.3 W average value. The cogeneration system can be utilized for the heat source temperature lower than 170 o C. Total energy efficiency increases from 0.293 to 0.417 then decreases to 0.407 while exergy efficiency increases from 0.12 to 0.16. Nomenclaturec Specific heat (kJ/(kg. o C)) COP Coefficient of performance E Exergy (kJ/kg) Greek letters ΔH Enthalpy of HTS adsorbent Δx Adsorption quantity variation (kg/kg) ρ Density of ammonia (kg/m 3 )

Geothermal energy use in hydrogen production: A review

“…99 Among various renewable energy sources, geothermal energy utilization has been investigated widely in producing hydrogen. Cogeneration systems produce electricity as well as other worthwhile types of energy (eg, heat, hot water, potable water, hydrogen, etc.)…”

“…from a specific energy source. 99 Among various renewable energy sources, geothermal energy utilization has been investigated widely in producing hydrogen. Hydrogen can be produced from all or part of the generated power from a geothermal plant through an electrolysis unit.…”

Exploration of ammonia resorption cycle for power generation by using novel composite sorbent

“…Similar with LiBr-water absorption cycle, physisorption cycles for power generation are relatively difficult for real application since water and methanol-based cycles often work at vacuum pressure, which result in high requirements for the expander [31]. Comparably, several lab-scale ammonia-based sorption systems were established to investigate their cogeneration performance [32,33]. Except for experimental investigation, theoretical analysis of these power generation cycles all lies in power output and thermal efficiency by using the first and second law of thermodynamics.…”

Investigation on innovative thermal conductive composite strontium chloride for ammonia sorption refrigeration

“…The highest thermal conductivity of the composite sorbent was able to reach 88.1 W•m -1 •K -1 while the permeability decreased to 10 -14 m 2 [12]. Nonetheless, one drawback is that the price of ENG-TSA is times higher than that of ENG, and the limited improvement could be achieved for the real application of sorption refrigeration system [13,14]. It is worth noting that thermal conductivity of the composite sorbent has improved significantly through various matrix when compared with the value of granular chlorides.…”