Experimental investigation of a MnCl2/CaCl2-NH3 two-stage solid sorption freezing system for a refrigerated truck

Abstract

a b s t r a c tA MnCl 2 /CaCl 2 -NH 3 two-stage solid sorption freezing system consisting of a MnCl 2 sorption bed, a CaCl 2 sorption bed, an evaporator and a condenser is established for a refrigerated truck, for which the required refrigerating capacity is 1.13 kW at a refrigerating temperature of À5 C. Composite adsorbents of MnCl 2 and CaCl 2 developed by expanded natural graphite treated with sulfuric acid are utilized. The sorption/desorption process and the resorption process are coupled in the two-stage cycle. The experimental results show that the maximum refrigerating capacity of 1.25 kW and COP (coefficient of performance) of 0.143 are obtained at a resorption time of 120 min when the hot air and refrigerating temperatures are 230 C and À5 C, respectively. In addition, the refrigerating capacity of 1.19 kW is achieved even when the hot air temperature is as low as 210 C, and such a result can satisfy the requirement for transporting fresh goods. The refrigerating capacity is 1.32 kW when the hot air and refrigerating temperatures are 270 C and À10 C, respectively, and the data are higher than the required refrigerating capacity. However, for refrigerating temperatures of À15 C and À18 C, the refrigerating capacity experimentally obtained could meet the requirement only when a truck is utilized for longdistance transportation.

Refrigerated Transport: State of the Art, Technical Issues, Innovations and Challenges for Sustainability

“…Gao et al [59] conducted an experimental study in which they developed and tested a two-stage MnCl 2 /CaCl 2 -NH 3 adsorption system, powered by engine exhaust gases. A light-duty vehicle with an overall thermal transmission coefficient of 0.35 W/(m 2 •K) was considered.…”

“…Required refrigerating capacity under different refrigerating temperatures. Reprinted from ref [59]. with permission from Elsevier.…”

Optimal Design of Combined Two-Tank Latent and Metal Hydrides-Based Thermochemical Heat Storage Systems for High-Temperature Waste Heat Recovery

“…There are different classes of thermochemical (sorbents) materials that fit the scope. In the literature, a great number of these thermochemical materials deals with ammoniated [16][17][18][19][20], hydrated salts [21][22][23][24][25] and metal hydrides [26][27][28][29][30][31]. Furthermore, each type of material has its own advantages and shortcomings.…”

Metal Hydride Beds-Phase Change Materials: Dual Mode Thermal Energy Storage for Medium-High Temperature Industrial Waste Heat Recovery

“…Furthermore, thermochemical energy materials allow for long-term energy storages as compared to PCMs, which are prone to thermal losses when stored for a long period. To date, metal hydrides, salts (e.g., metal halides) hydrates and ammoniates are the most utilized thermochemical materials for closed sorption systems driven by waste-heat intended for refrigeration [28][29][30][31][32][33][34], heat pumps and transformer applications [34][35][36][37]. The well-accepted layout of these sorption systems is two tanks interconnected, filled with a high temperature (HT) sorbent in one side, and a low temperature (LT) sorbent in the other side.…”

“…Furthermore, the integration of the heat recovery system improved the COP by 43% and cooling power by 4%. Gao et al [30] experimentally investigated a two-stage solid sorption freezing system based on the adsorbents pair (two-bed) MnCl 2 -CaCl 2 -NH 3 . The experimental results showed that a maximum refrigerating capacity of 1.25 kW and a coefficient of performance (COP) of 0.143 were obtained in 2 h resorption process at the waste heat and refrigerating temperatures of 230 • C and −5 • C, respectively.…”