Thermodynamic performance assessment of solar-based combined power and absorption refrigeration cycle

2020 ◽  
Vol 31 (3) ◽  
pp. 232
Author(s):  
Osama Khan ◽  
Faizan Khalid ◽  
Mohd Parvez
2019 ◽  
Vol 27 (01) ◽  
pp. 1950003 ◽  
Author(s):  
Salem Yosaf ◽  
Hasan Ozcan

In this study, three novel modifications of ejector-absorption refrigeration cycles (E-ARC) are investigated to evaluate the effect of ejector location on cycle performances. In the first modification (triple pressure level absorption refrigeration cycle TPL-ARC), the ejector is located at the evaporator inlet. In the second modification (double ejector absorption refrigeration cycle DE-ARC), two ejectors are used; one is located at the evaporator inlet and the other at the absorber inlet, which are coupled to each other. In the third modification (low pressure condenser absorption refrigeration cycle LPC-ARC), the steam ejector is installed at the downstream of the vapor generator discharging line. An additional flow splitter is integrated to the steam ejector outlet and part of the vapor is extracted and returned to the absorber at a pressure equal to the diffuser pressure. Effect of ejector location on thermodynamic performances are evaluated considering three different working fluids, namely ammonia–water solution (NH3–H2O), lithium bromide-water solution (H2O–LiBr), and lithium chloride–water solution (H2O–LiCl). Even though all three configurations enhance the conventional absorption refrigeration cycle (C-ARC) performances, the LPC-ARCs work at high temperature and improve the cycle performance. The TPL-ARC proves to improve the COP and exergy efficiency up to 9.14% and 7.61%, respectively, presenting the highest thermodynamic performance enhancement and lowest operating temperature.


Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4200 ◽  
Author(s):  
Yiqun Li ◽  
Na Li ◽  
Chunhuan Luo ◽  
Qingquan Su

For an absorption cycle, a ternary working pair LiBr–[BMIM]Cl(2.5:1)/H2O was proposed as a new working pair to replace LiBr/H2O. The thermodynamic properties including specific heat capacity, specific enthalpy, density, and viscosity were systematically measured and fitted by the least-squares method. The thermodynamic performance of a double-effect absorption refrigeration cycle based on LiBr–[BMIM]Cl(2.5:1)/H2O was investigated under different refrigeration temperatures from 5 °C to 12 °C. Results showed that the ternary working pair LiBr–[BMIM]Cl(2.5:1)/H2O had advantages in the operating temperature range and corrosivity. Compared with LiBr/H2O, the operating temperature range was 20 °C larger, and the corrosion rates of carbon steel and copper were reduced by more than 50% at 453.15 K. However, the double-effect absorption refrigeration cycle with LiBr–[BMIM]Cl(2.5:1)/H2O achieved a coefficient of performance (COPc) from 1.09 to 1.46 and an exergetic coefficient of performance (ECOPc) from 0.244 to 0.238, which were smaller than those based on LiBr/H2O due to the higher generation temperature and larger flow ratio.


Entropy ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 546 ◽  
Author(s):  
Yiqun Li ◽  
Na Li ◽  
Chunhuan Luo ◽  
Qingquan Su

When compared with LiBr/H2O, an absorption refrigeration cycle using CaCl2/H2O as the working pair needs a lower driving heat source temperature, that is, CaCl2/H2O has a better refrigeration characteristic. However, the crystallization temperature of CaCl2/H2O solution is too high and its absorption ability is not high enough to achieve an evaporation temperature of 5 °C or lower. CaCl2-LiNO3-KNO3(15.5:5:1)/H2O was proposed and its crystallization temperature, saturated vapor pressure, density, viscosity, specific heat capacity, specific entropy, and specific enthalpy were measured to retain the refrigeration characteristic of CaCl2/H2O and solve its problems. Under the same conditions, the generation temperature for an absorption refrigeration cycle with CaCl2-LiNO3-KNO3(15.5:5:1)/H2O was 7.0 °C lower than that with LiBr/H2O. Moreover, the cycle’s COP and exergy efficiency with CaCl2-LiNO3-KNO3(15.5:5:1)/H2O were approximately 0.04 and 0.06 higher than those with LiBr/H2O, respectively. The corrosion rates of carbon steel and copper for the proposed working pair were 14.31 μm∙y−1 and 2.04 μm∙y−1 at 80 °C and pH 9.7, respectively, which were low enough for engineering applications.


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