Low-temperature Refrigeration Research Articles

Comparison of the biogas upgrading methods as a transportation fuel

Abstract The aim of this study is investigating and analyzing the water scrubbing, cryogenic separation, amine scrubbing and caustic wash biogas upgrading processes. In order to comparing the upgrading processes, input condition is supposed to be fixed for all of the processes. The results of this study indicate that although amine scrubbing process consumes less power but the required hot utility is higher than other upgrading methods. In the cryogenic process, high pressure operating condition needs high compression power. This process also needs low temperature refrigeration system. Water wash process is a simple and economic method which has acceptable separation efficiency, but caustic wash is more efficient than other methods and its energy consumption is reasonable.

Electrical, magneto-transport and significant thermoelectric properties of Te-rich ZrTe5+δ polycrystals

The transition metal pentatelluride ZrTe5 has been studied extensively due to high thermoelectric power factors for potential applications in low-temperature refrigeration devices. Recent studies reveal that the physical properties of ZrTe5 are strongly dependent on Te concentration. Here, we have synthesized the Te-rich ZrTe5+δ polycrystalline by direct solid-state reaction and systematically investigated the electrical, magneto-transport and thermoelectric properties. Temperature-dependent resistivity and magneto-transport characterizations substantiate that ZrTe5+δ is a p-type (hole-doped) semiconductor. Besides, Seebeck coefficient is positive and linearly increases with T when T is within 10–150 K, and saturated to 120 μV K−1. Remarkably, a significant figure of merit ZT is obtained (∼0.037 at T = 300 K), which is higher than those in polycrystalline ZrTe5 (∼0.026) and sister compound HfTe5 (∼0.016) measured at 300 K. The significant thermoelectric performance of ZrTe5+δ is attributed to its low electrical resistivity (∼5 mΩ·cm), relative low thermal conductivity (∼2.0 W·K−1·m−1) and moderate Seebeck coefficient (∼120 μV K−1) at 300 K. Our work demonstrates the defect engineering, through delicate synthesis method, is an effective way to improve the thermoelectric property of ZrTe5.

Theoretical investigation on performance improvement of a low-temperature transcritical carbon dioxide compression refrigeration system by means of an absorption chiller after-cooler

A Transcritical Carbon dioxide Compression (TCC) refrigeration system is a suitable tool to provide low-temperature refrigeration, but with a low COP. To improve the performance of a TCC, different combinations of Liquid Suction Heat Exchanger (LSHE), after-cooler and two-stage compression are embedded into the system configuration. The cooling load of the after-cooler is provided by an Absorption Chiller (ABSC) and the required heating energy to run the ABSC is recovered from the hot refrigerant leaving the compressors of the TCC. Eleven modified configurations are proposed and modeled in detail by EES software and energy and exergy analyzes are performed for each configuration. The results showed that the two-stage compression is a suitable method to upgrade the TCC system performance from both first and second laws of thermodynamics view point. The COP of a typical two-stage TCC is calculated to be 207% higher than its single-stage counterpart, in an evaporator temperature of −50 °C. It is also concluded that the combination of a two-stage compression TCC and a single-effect LiBr ABSC, performs with the highest performance. This combination increases the TCC system performances for about 4 and 2 times compared to single-stage and two-stage TCCs, respectively. A parametric study also revealed that well-calculated operating conditions are fundamental in design of TCCs to gain the highest performance.

Survey of characteristics of dairy-protein concentrates in the low-temperature storage process

The influence of low-temperature refrigeration treatment on the structure and organoleptic parameters of milk-protein concentrates (MPC), obtained with the use of cranberry and viburnum purees, was determined and analyzed. The study of low-temperature phase transitions and glass transition of the MPC structure was made during cooling at a rate of 200 °C/min by immersion of the samples in liquid nitrogen. It was found that the structure of concentrates is amorphous, it can be considered relatively stable in the solid state. It was determined that the leaps of heat absorption were larger for the concentrates obtained with the use of berry purees than for the control sample. This indicates a large amount of bound liquid in the products, what allows reducing crystallization and avoiding significant structural changes. The analysis of changes in the color-parametric characteristics of MPC indicates an increase in the intensity of light reflection at 550...700 nm, that is, in the yellow-red area of the spectrum, after 30 days of low-temperature storage. There are gradual yellowing and darkening of the product. The theoretical and experimental research allowed determining the rational periods of storage of MPC in the frozen state, which are not more than 30 days at temperatures not higher than –20 °С. The possibility of predicting changes in the quality of food products obtained with the use of MPC, if stored at low temperatures, was obtained

Magnetic properties and magnetocaloric effects of RNiSi2 (R= Gd, Dy, Ho, Er, Tm) compounds

Orthorhombic CeNiSi2-type polycrystalline RNiSi2 (R=Gd, Dy, Ho, Er, Tm) compounds were synthesized and the magnetic and magnetocaloric properties were investigated in detail. The transition temperatures of RNiSi2 compounds are all in a very low temperature range (<30 K). As temperature increases, all of the compounds undergo an AFM to PM transition (GdNiSi2 at 18 K, DyNiSi2 at 25 K, HoNiSi2 at 10.5 K, ErNiSi2 at 3 K and TmNiSi2 at 3.5 K, respectively). ErNiSi2 compound shows the largest (ΔSM)max (maximal magnetic entropy change) among these compounds. The value of (ΔSM)max is 27.9 J/kgK under a field change of 0-5 T, which indicates that ErNiSi2 compound is very competitive for practical applications in low-temperature magnetic refrigeration in the future. DyNiSi2 compound shows large inverse MCE (almost equals to the normal MCE) below the TN which results from metamagenitic transition under magnetic field. Considering of the normal and inverse MCE, DyNiSi2 compound also has potential applications in low-temperature multistage refrigeration.

Magnetic and magnetocaloric effects of Eu<sub>0.9</sub><i>M</i><sub>0.1</sub>TiO<sub>3</sub> (<i>M</i>=Ca, Sr, Ba, La, Ce, Sm) compounds

EuTiO<sub>3</sub> is a direct band-gap semiconductor material and exhibits antiferromagnetism with large magnetic entropy change around the liquid helium temperature. The ferromagnetic state can be changed into antiferromagnetic state through lattice constant change and electron doping by element substitution due to strong spin-lattice coupling coexistence of ferromagnetic coupling, and antiferromagnetic coupling. The values of magnetic entropy change can be effectively improved under low magnetic field change after changing into ferromagnetism. Samples of EuTiO<sub>3</sub> and Eu<sub>0.9</sub><i>M</i><sub>0.1</sub>TiO<sub>3</sub> (<i>M</i>=Ca, Sr, Ba, La, Ce, Sm) are prepared by the sol gel method. The Eu<sub>0.9</sub>Ca<sub>0.1</sub>TiO<sub>3</sub> exhibits the antiferromagnetism due to similar ion radius. The ferromagnetic coupling between Eu<sub>0.9</sub>Sr<sub>0.1</sub>TiO<sub>3</sub> and Eu<sub>0.9</sub>Ba<sub>0.1</sub>TiO<sub>3</sub> is enhanced, for alkaline earth metal (Sr and Ba) has larger ion radius, which is beneficial to improving the magnetocaloric effect under low magnetic field. Electron doping can inhibit the antiferromagnetic coupling because the extra carrier may occupy the Ti 3d and reduce the hybridization of Eu 4f-Ti 3d-Eu 4f. When the electron doping concentration is greater than 10%, the spin polarization rate of Ti 3d state on the Fermi surface is negative, resulting in the transition from antiferromagnetic to ferromagnetic state. When the Eu ions are replaced with the Sm ions (Sm ion radius is similar to Eu ion radius), the ferromagnetic coupling is enhanced. However, when the Eu ions are replaced with the La or Ce ions, the samples show strong ferromagnetism, for the lattice constant and electron doping are increased. A giant reversible magnetocaloric effect and large refrigerant capacity for each of Eu<sub>0.9</sub><i>M</i><sub>0.1</sub>TiO<sub>3</sub> (<i>M</i>=Sr, Ba, La, Ce) compounds are observed. Under the magnetic field change of 1 T, the values of maximum magnetic entropy change and refrigeration capacity are 9.8 J/(kg·K) and 36.6 J/kg for Eu<sub>0.9</sub>Sr<sub>0.1</sub>TiO<sub>3</sub>, and 10 J/(kg·K) and 45.1 J/kg for Eu<sub>0.9</sub>Ba<sub>0.1</sub>TiO<sub>3</sub>. The values of maximum magnetic entropy change of Eu<sub>0.9</sub>La<sub>0.1</sub>TiO<sub>3</sub> and Eu<sub>0.9</sub>Ce<sub>0.1</sub>TiO<sub>3</sub> are 10.8 J/(kg·K) and 11 J/(kg·K), respectively, which are larger than that of EuTiO<sub>3</sub> (9.8 J/(kg·K)). The values of refrigeration capacity are 39.3 J/kg and 51.8 J/kg, which are also improved compared with those of EuTiO<sub>3</sub>. In a word, the results suggest that these compounds could be considered as good candidates for low-temperature and low-field magnetic refrigerant.

Influences of La and Ce doping on giant magnetocaloric effect of EuTiO**Project supported by the National Key Research and Development Program of China (Grant No. 2017YFB0702704), the National Natural Science Foundation of China (Grant Nos. 11504266, 51676198, and 51371075), the Tianjin Natural Science Foundation, China (Grant No. 17JCQNJC02300), and the National Key Foundation for Exploring Scientific Instrument of China (Grant

Giant reversible magnetocaloric effects and magnetic properties in Eu0.9R0.1TiO3 (R = La, Ce) are investigated. The antiferromagnetic ordering of pure EuTiO3 can significantly change to be ferromagnetic as substitution of La (x = 0.1) and Ce (x = 0.1) ions for Eu2+ ions. The values of and RC are evaluated to be 10.8 J/(kgK) and 51.8 J/kg for Eu0.9Ce0.1TiO3 and 11 J/(kgK) and 39.3 J/kg for Eu0.9La0.1TiO3 at a magnetic field change of 10 kOe, respectively. The large low-field enhancements of and RC can be attributed to magnetic phase transition. The giant reversible MCE and large RC suggest that Eu0.9R0.1TiO3 (R = La, Ce) compounds could be promising materials in low temperature and low magnetic field refrigerants.

Low Temperature Refrigeration as an Alternative Anti-Pest Treatment of Dates

Abstract Large amounts of dates are produced and consumed around the world each year. Apomyelois ceratoniae causes main losses during storage and export of date fruit. Fumigation is the most widely used treatment to prevent postharvest losses. However, this treatment negatively affects the biological value of dates, environmental and economic parameters of production. Widespread fumigation agent methyl bromide is toxic to a human body and contributes to the destruction of the ozone layer. The aim of the current work was to find a new method based on the use of low temperature refrigeration to reduce the pest and insect infestation preserving the nutritive value of dates during cold storage at the same time. A. ceratoniae mortality under different temperatures and dates respiration rate, sugar, organic acids, pectic substances content and sensorial characteristics were studied. The results indicate that at −18 °С the A. ceratonie larva dies within 2 h, the eggs and larvae - within 24 h respectively. Thus, it is clearly shown that there is no need in using chemicals or irradiation to prevent dates pests. Physicochemical and organoleptic proprieties of dates were satisfactory during 360 d at −18 °С and during 180 d at +4 °С. The low temperature refrigeration and storage at −18 °С is recommended for dates to prevent pests and quality losses. It is apparently advantageous for environment and climate if compared with other anti-pest treatment variants.

Giant reversible magnetocaloric effect in a multiferroic GdFeO3 single crystal

The magnetocaloric properties of single crystalline ${\mathrm{GdFeO}}_{3}$ have been investigated in the temperature range 2--36 K by magnetization and heat-capacity measurements. Remarkably large and reversible magnetic entropy change, $\mathrm{\ensuremath{\Delta}}{S}_{\mathrm{m}}=\ensuremath{-}52.5$ J/kg K, has been observed for a field change of 0--9 T. The adiabatic temperature change, $\mathrm{\ensuremath{\Delta}}{T}_{\mathrm{ad}}$, is also found to be very large, 22 K, slightly above the antiferromagnetic ordering temperature (${T}_{N}^{\text{Gd}}=2.5$ K) of the ${\mathrm{Gd}}^{3+}$ moment, for a field change of 0--8 T. These magnetocaloric parameters remain large down to the lowest temperature measured and are significantly larger than that reported for the other members of rare-earth ($R$) orthoferrites ($R{\mathrm{FeO}}_{3}$) and several potential magnetic refrigerants in the same temperature range. Both $\mathrm{\ensuremath{\Delta}}{S}_{\mathrm{m}}$ and $\mathrm{\ensuremath{\Delta}}{T}_{\mathrm{ad}}$ are also quite large for a small field change. The large values of magnetocaloric parameters suggest that ${\mathrm{GdFeO}}_{3}$ could be considered as a potential refrigerant in low-temperature magnetic refrigeration technology, such as liquefaction of hydrogen in the fuel industry. Moreover, ${\mathrm{GdFeO}}_{3}$ has very low electrical conductivity and exhibits no thermal and field hysteresis in magnetization, fulfilling the necessary conditions for a good magnetic refrigerant.

Low field induced large magnetic entropy change in the amorphousized Tm60Co20Ni20 ribbon

The magnetic properties and magnetic entropy change of amorphousized Tm60Co20Ni20 ribbon were systematically studied. The results indicate that the Tm60Co20Ni20 amorphous ribbon reveals a second order magnetic transition (paramagnetic to ferromagnetic state) based on the Arrott plots and rescaled magnetic entropy change curves. A large magnetic entropy change is achieved around its Curie temperature of TC ∼6.7 K. Under the magnetic field change (ΔΗ) of 0–5 T, the maximum values of magnetic entropy change (−ΔSMmax) and relative cooling power (RCP) are 17.1 J/kg K and 273 J/kg, respectively. In particular, under a relative low ΔΗ of 0–2 T, a large magnetic entropy change of 11.8 J/kg K reaches, making it attractive in the field of low-temperature magnetic refrigeration.

Effect of tissue frozen on quantitative optical properties using optical coherence tomography.

The purpose is to demonstrate the optical charactering concerning nasopharyngeal tissue of pig by fresh sections and frozen correlating sections with optical coherence tomography (OCT). After being imaged on a fresh specimen, samples are then stored in low temperature refrigerators (-80°C) for one year for the second OCT measurement. The OCT structure of the epithelium, lamina propria, and the basement membrane are still resolvable; the median scattering coefficients and anisotropy factors fitting from OCT images based on the multiple scattering effects for epithelium are 27.6 mm-1 [interquartile range (IQR) 23.6 to 29.3 mm-1] versus 22.5 mm-1 (IQR 20.5 to 24.4 mm-1), 0.86 (IQR 0.81 to 0.9) versus 0.88 (IQR 0.87 to 0.9) for fresh and frozen tissue, respectively; and 10.2 mm-1 (IQR 8.1 to 13.6 mm-1) versus 9.6 mm-1 (IQR 8.1 to 13.8 mm-1), 0.96 (IQR 0.93 to 0.98) versus 0.92 (IQR 0.9 to 0.98) for lamina propria, respectively. The results show that the frozen storage method can be used for OCT research.

Experimental investigation of an ejector-enhanced auto-cascade refrigeration system

This study presents the experimental investigation of an ejector-enhanced auto-cascade refrigeration cycle (EARC) with zeotropic refrigerant R134a/R23. Performance comparisons among the EARC and two conventional cycles were conducted at selected operating conditions. The effects of ambient temperature, charged mass fraction ratio of the mixture, throttle valve opening, and heat load on the performance characteristics of the EARC were investigated. The results indicated that the EARC had more advantages in terms of lower refrigeration temperature and higher energy utilization efficiency over the conventional cycles, and the coefficient of performance (COP) and exergy efficiency improvements of the EARC reached up to 9.6% and 25.1%, respectively. The throttle valve opening was optimal with respect to the maximum system exergy efficiency determination. The refrigerant R134a/R23 with the optimal mass fraction ratio of 0.70/0.30 was proposed.

Experimental research of low-temperature throttling refrigerator for cryoconservation of medical and biological objects

Results of experimental research of low-temperature multicomponent mixed-refrigerant throttling refrigerator are given. Appliance of refrigerator in new domestic-made ultralow-temperature freezer for cryoconservation and long-term storage of medical and biological objects at temperature minus 150°C is described. Within experimental research, test bench with development prototype of ultralow-temperature medical freezer is made. Experimental and theoretical studies are compared. Availability and amount of local composition shift is defined. Ways to improve simulation model and increase energy efficiency of cryostatting systems are determined.

Observation of giant magnetocaloric effect under low magnetic fields in EuTi1–xcoxo3**Project supported by the National Natural Science Foundation of China (Grant Nos. 11504266, 51271192, 51322605, and 51371075) and the Natural Science Foundation of Tianjin, China (Grant No. 17JCQNJC02300).

The magnetic properties and magnetocaloric effect (MCE) in EuTi1−xCoxO3 (x = 0, 0.025, 0.05, 0.075, 0.1) compounds have been investigated. When the Ti4+ ions were substituted by Co2+ ions, the delicate balance was changed between antiferromagnetic (AFM) and ferromagnetic (FM) phases in the EuTiO3 compound. In EuTi1−xCoxO3 system, a giant reversible MCE and large refrigerant capacity (RC) were observed without hysteresis. The values of were evaluated to be around 10 J⋅kg−1⋅K−1 for EuTi0.95Co0.05O3 under a magnetic field change of 10 kOe. The giant reversible MCE and large RC suggests that EuTi1−xCoxO3 series could be considered as good candidate materials for low-temperature and low-field magnetic refrigerant.

Experimental investigation on two-phase frictional pressure drop of zeotropic mixtures of R50/R170 in a horizontal tube

In recent years, due to the environmental issues, suitable substitutes are being searched to replace the traditional chlorinated refrigerants. With zero ozone depleting potential, low global warming potential and high thermodynamic performance, the hydrocarbons are suitable selections in refrigerators and heat pump systems. As hydrocarbons, R50 and R170 are also the important parts of the natural gas and often-used components in mixture refrigerants for the low-temperature Joule-Thomson refrigerator. As the flow characteristics play important parts in the design and optimization of the heat exchangers in refrigerators and air-conditioning systems, the two-phase frictional pressure drop should be well examined and analyzed. Although there are massive experimental studies on two-phase frictional pressure drop of hydrocarbons in horizontal tubes, the published experimental investigations for zeotropic mixtures of R50/R170 are rare. Therefore, it′s desirable to conduct an experimental investigation on two-phase frictional pressure drop of zeotropic mixtures of R50/R170 in a horizontal tube and find a suitable correlation. In this paper, two-phase frictional pressure drop of R50/R170 mixtures (0.27:0.73, 0.54:0.46 and 0.7:0.3 by mole) was studied experimentally in a horizontal tube with inner diameter of 4 mm. The tests were carried out at saturation pressures from 1.5 MPa to 2.5 MPa for mass fluxes from 99 kg m−2 s−1 to 255 kg m−2 s−1, vapor qualities from 0 to 0.9. The uncertainty for the pressure drop was 40 Pa and the uncertainties for the vapor quality with a 95% confidence interval were less than 11.74% under the employed operation conditions. The effects of mass flux, saturation pressure, vapor quality and concentration on two-phase frictional pressure drop were examined and analyzed. Some conclusions can be drawn that (1) the frictional pressure drops increase with the increasing mass flux and the impact becomes more obvious when the vapor quality increases; (2) the frictional pressure drops decrease with the increasing saturation pressure and the impact enhances when the vapor quality increases; (3) the frictional pressure drops increase with the increasing vapor quality and then change to be smooth even decline at high vapor qualities. And the effect of vapor quality enhances as the mass flux increases and the saturation pressure decreases; (4) the frictional pressure drops of pure R50 are lower than that of all R50/R170 mixtures and the frictional pressure drops of the initial concentration of R50/R170 mixtures at 0.27:0.73 are also lower than that of other two initial concentrations of R50/R170 mixtures. Their differences are not obvious at low vapor qualities, while the differences enhance when the mass flux and vapor quality increase as well as the saturation pressure decreases. The influence of concentration may be mainly related to the difference of the vapor densities. In addition, the experimental data were compared with twenty well-known frictional pressure drops correlations. The comparison results showed that the Friedel correlation showed the best agreement with a mean absolute relative deviation of 19.26% and 87.45% of points in the deviation bandwidth of ±30%.

Magnetization, ESR, and giant magnetocaloric effects in nanocrystals of Haldane-chain compound Gd2BaNiO5

The magnetization and electron spin resonance (ESR) in nanocrystals of Haldane-chain antiferromagnet Gd2BaNiO5 have been investigated. It is revealed that a reduction in crystal size results in an enhancement of magnetization due to a large number of paramagnetic Gd3+ and Ni2+ ions forming on the surfaces of nanocrystals. The smallest nanoparticles with an average size of 45 nm behave like a paramagnet, as evidenced by our ESR data. Upon application of an external magnetic field, the weakly coupled spins can be well aligned along the direction of the magnetic field, giving rise to a giant entropy change of −ΔSm = 36 J⋅kg−1⋅K−1 at 2 K in a field range of 0–7 T. This value is larger than those of most rare-earth-based compounds reported. The large value of −ΔSm, together with the absence of thermal and field hysteresis, makes Gd2BaNiO5 nanocrystals very promising candidates for low-temperature magnetic refrigeration.

Comparative analysis on the energy use and environmental impact of different refrigeration systems for frozen food supermarket application

In this paper the impact on the store’s energy use by different refrigeration systems, remote and centralised, is investigated as well as their environmental impact. The study is performed using the energy simulation program EnergyPlus in a reference baseline model which has been verified against measured energy and environmental conditions data. The refrigeration system of the case study includes plugged-in display cabinets to serve both medium temperature (MT) and low temperature (LT) refrigeration loads. Centralised systems are compared with the remote plugged-in refrigeration cabinets. The different refrigeration systems studied are, a) two parallel centralised systems for MT and LT loads, b) two parallel cascade systems (R134a/CO2) for MT and LT loads and c) a transcritical CO2 booster. The study is performed for DSY London weather file to capture the risk of warmer than a typical year consequences in centralised refrigeration systems operation. Besides these refrigeration systems, the CO2 transcritical appears as the one of the most promising replacement in terms not only of energy use reduction due to its high efficiency in London climate but on its low contribution to global warming as well.

Cascade refrigeration system with inverse Brayton cycle on the cold side

Low temperature refrigeration of cold stores poses some specific issues: single stage, vapour compression cycles have modest COP at low evaporation temperature; cold evaporator surfaces require de-frosting and a fan for air circulation; a part of the refrigeration load may be delivered at intermediate temperature levels, e.g. for the cold store loading dock.Cascade system may improve the COP and add flexibility on the temperature levels and working fluids, but the problems related to the cold evaporator surface remain unsolved.The refrigeration system presented herein features a cascade configurationcombining a vapour compression cycleand an inverse Braytoncycle. Both cycles use “natural” fluids, complying with strictest regulations. The top cycle uses Ammonia in order to increase efficiency, while the bottom cycle uses air, which directly circulates in the cold space and hence eliminates the cold heat exchanger. A detailed thermodynamic analysis allows a complete screening of the relevant design parameters for an overall system optimization.The results show that, notwithstanding the intrinsic gap of efficiency suffered by the Brayton cycle, the proposed system features an acceptable global performance and widens the implementation field of this technology. This system configuration shows a COP 50% higher than the corresponding simple Brayton cycle at temperatures of the refrigerated storage of −50°C.

Vapor-liquid and vapor-liquid-liquid equilibrium measurements and correlation of the binary mixtures 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) + (tetrafluoromethane (R14), trifluoromethane (R23), octafluoropropane (R218), nitrogen (R728) and argon (R740)) and ethane (R170) + trifluoromethane (R23)

Vapor-liquid equilibrium data for mixtures R14 + R1234yf, R23 + R1234yf, R218 + R1234yf, R728 + R1234yf, R740 + R1234yf and R170 + R23 were measured in the temperature range of 153 … 273 K and at pressures up to 5 MPa. Vapor-liquid-liquid equilibrium of R170 + R23 is reported below the upper critical solution temperature of 186 K. The measurements were performed with a vapor recirculation apparatus. Azeotropic behavior was found for R218 + R1234yf and R170 + R23. The experimental data were correlated together with existing data from literature, using a modified Peng-Robinson equation of state. The results will be used for the design of low-temperature mixed refrigerant cycles with R1234yf mixtures.

Energetic, Exergetic, Economic and Environmental (4E) analysis of a solar assisted refrigeration system for various operating scenarios

The objective of this work is to investigate the yearly performance an absorption-compression cascade refrigeration system driven by solar energy. Different operating scenarios are examined by testing different combinations of refrigeration and condensation temperatures. Evacuated tube collectors coupled to a storage tank are selected to be used for feeding the refrigeration system with the proper heat demand. LiBr-H2O and R134a are selected as working pair in the absorption cycle and refrigerant in the compression cycle respectively. The analysis is performed in energetic, exergetic, economic and environmental terms with a developed and validated model in EES (Engineering Equation Solver). According to the final results, the cascade system, in cases with low refrigeration temperatures is better economically while in higher refrigeration temperatures presents the greater percentage of electricity savings. On the other hand, higher heat rejection temperature leads both to higher economic indexes and to higher electricity savings. For the case of heat rejection at 40°C and refrigeration at −20°C, the electricity savings are found 53.98%, the IRR 6.6% and the payback period close to 14years.