Performance Of Refrigerator Research Articles

Optimal design modeling of an energy system for a near-zero energy restaurant with green hydrogen energy storage systems

In this research, we want to analyze the consumed energy of an nZEB restaurant in a typical city to anticipate tourists. The energy of this restaurant is supplied through solar panels and electricity grids and we use the hydrogen storage tool because of its advantages to store energy. In this regard, Using the Fanger model, the thermal comfort of passengers was assessed, the energy consumption rate was obtained for the refrigerator, HVAC, lights, and systems, and the consumed water of the restaurant is supplied. Trnsys software was used for this simulation, and the transient performance of the mentioned nZEB in a year is evaluated by Trnsys software. PV panels are used to supply the consumed electricity of the building, A tank stores hydrogen and the extra produced electricity that can be used as needed if sunlight is scarce or electricity is needed. A solar collector is used to generate hot water, and a water tank is used to store the generated hot water. A heat pump is used to supply the cooling load and heating. The consumed hot water by the dwellers is supplied using the stored hot water. With the help of MATLAB software, the Fanger model is used to evaluate the thermal comfort of dwellers. The energy and performance of the restaurant refrigerator are obtained by TRNSYS and EES software. The results show that a significant part of the restaurant's electricity is supplied using 140 PV panels with 0.89 area. In addition, the initial hydrogen pressure tank was lower than the final hydrogen pressure tank. In this regard, energy for the heat pump, refrigerator, light, pump, fan, and compressors is supplied well. Using 16 square meters of solar collectors, the building gets its hot water. Furthermore, the restaurant's air conditioning system provides thermal comfort throughout the year. As a result, using the building roof area for ZEB can significantly reduce the greenhouse gas emissions of Doha.

Thermal Management System of Vapor Compression for Downhole Instrument

Abstract As the depth of oil and gas exploration increases, downhole electronics face the threat of high-temperature failure. At present, passive cooling technology has the problem of short working time, while active cooling technology has low energy utilization. This paper presents a thermal management system of vapor compression with a combination of active and passive cooling. The system uses insulation materials to isolate the high-temperature environment, thermally conductive silicone grease to strengthen the heat exchange in the evaporator, and vapor compression refrigeration cycles to absorb internal heat. The coefficient of performance (COP), exergy destruction and exergy efficiency of octane, nonane, and cyclohexane as refrigerants were examined, and the effects of different insulation materials on refrigeration performance were studied from both theoretical and numerical perspectives. The results showed that cyclohexane exhibited the best cooling capacity with a COP of 1.296 and a exergy efficiency of 49.21%. The thermal management system cooling performance is optimal when the insulation material is a vacuum flask, with an effective cooling capacity of 121.7 W.

Superconductor–quantum dot hybrid coolers

We propose a refrigeration scheme in a mesoscopic superconductor-quantum dot hybrid device. The setup can significantly cool down a normal metal coupled to the device by applying a bias voltage across the system. We demonstrate that the cooling power can be as large as 0.05$\Delta_0^2/h$ where $\Delta_0$ is the absolute value of superconducting order parameter. In contrast to previous proposals, our device operates without any magnetic elements such as ferromagnetic reservoirs or Zeeman splittings. The refrigeration scheme works over a broad parameter range and can be optimized by tuning system parameters such as level position and bias voltage. Our theory self-consistently determines the temperature drop of the normal reservoir in the nonlinear transport regime including electron-electron interactions at the mean field level. Finally, we evaluate the refrigeration performance and find efficiencies as large as half of the Carnot bound for realistic values of the coupling strength.

Study on the performance of thermoelectric refrigerator under natural convection heat transfer condition

Refrigeration using thermoelectric cooler (TEC) is a hotspot and frontier issue, but the forced heat dissipation apparatus poses problems that limit its application. In this paper, a thermoelectric refrigerator used under natural convection heat transfer conditions is presented, and numerical simulations and experimental analyses are performed. The maximum error between the simulation results and experimental results is 6.3%. The distributions of the temperature and velocity field in the refrigerator chamber are obtained, and the influences of the operating current and the height of fins on the temperature are analyzed. The novel design is that the number of thermoelectric legs in a single TEC is reduced to five pairs to reduce the heat generated on the hot side during operation. The performance of TEC is improved by increasing the average heat dissipation area. The results show that the air temperature in the chamber is finally stabilized at 12.2 ℃ under the ambient temperature of 29 ℃ and input electric power of 10.8 W. The air temperature difference inside and outside the thermoelectric refrigerator increases from 16.8 ℃ to 19.5 ℃ with the fin's height increasing, but the coefficient of performance (COP) changes little.

Use of an earthen clay pot refrigerator with a thermoelectric cooler for extending farm produce shelf life

Conventional cold storage systems increase the risk of damage and are no longer used for the long-term storage of agricultural products. Thus, newer affordable and energy-efficient storage systems are required for enhancing the shelf life of farm produce. We investigated the coefficient of performance (COP) of an earthen clay pot refrigerator with a thermoelectric cooler (TEC) and explored cooling strategies to enhance cooling and electrical performance for increasing the shelf life of farm produce. We used MATLAB Simulink to analyze Peltier TEC module efficiency. The intrinsic characteristics, including the Seebeck coefficient (α), thermal conductivity (K), and electrical resistance (R), were determined, forming the basis of the Peltier module in MATLAB Simulink. Thermal characteristics such as COP and cooling capacity were studied as a function of system voltage (Vin) and current (Iin). The model was equipped with a 12 V/6 A, 60 W TEC and was verified by simulation investigation. We also used psychrometric measures (e.g., wet bulb, dry bulb, and dew point temperatures and relative humidity) to determine the extent of wetness or dryness of an object and monitor other temperatures of the clay pot refrigerator. The results revealed that the ambient temperature and cold and hot side temperatures fundamentally affected TEC performance. The TEC extended the shelf life of tomatoes, potatoes, and spinach by 60% compared to those stored under ambient conditions, thereby reducing their wastage. In conclusion, earthen refrigeration using TEC doubled the shelf life of farm produce compared to storage under ambient conditions, saving money, resources, labor, and supplies and enabling the development of efficient and environmentally friendly refrigeration systems.

Study on Phase-Shift Mechanism and Kriging-Based Global Optimization of the Active Displacer Pulse Tube Refrigerators

Pulse tube refrigerators are widely used in certain special fields, such as aerospace, due to their unique advantages. Compared to a conventional phase shifter, the active displacer helps to achieve a higher cooling efficiency for pulse tube refrigerators. At present, the displacer is mainly studied by one-dimensional simulation, and the optimization method is not perfect due to its poor accuracy, which is not conducive to obtaining a better performance. Based on the current status of displacer research, phase-shift mechanisms of inertance tube pulse tube refrigerators and active displacer pulse tube refrigerators were firstly studied comparatively by multidimensional simulation, and then we determined the crucial effect properties that lead to a better cooling performance for the active displacer pulse tube refrigerator at different cooling temperatures. Finally, an efficient optimization method combining the Kriging model and genetic algorithm is proposed to further improve the cooling performance of the active displacer pulse tube refrigerator. The results show that the active displacer substantially improves the cooling performance compared to the inertance tube mainly by increasing the PV power and enthalpy flow in the pulse tube. The Kriging agent models of active displacer pulse tube refrigerator achieve 98.2%, 98.31%, 97.86%, and 97.32% prediction accuracy for no-load temperature, cooling capacity, coefficient of performance, and total input PV power, respectively. After optimization, the no-load temperature is minimally optimized for a 23.68% reduction compared to the initial one with a relatively high efficiency, and the founded optimization methods can also be weighted for multiple objectives, according to actual needs.

Effect of gas spacing and resonance frequency on theoretical performance of thermoacoustic refrigerators

In this paper, the design and analysis of 500 W thermoacoustic refrigerators for the temperature difference of 28 K using helium and air are discussed. Helium is the best working gas, but air is chosen to study the possibility of replacing helium for the future cost-effective refrigerator since it is much cheaper than helium. Heat and work flow equations of thermoacoustic refrigerators are discussed. The refrigerator models are optimized by normalizing the design parameters using Rott’s linear thermoacoustic theory. The effect of gas spacing expressed in terms of the thermal penetration depth in stack-heat exchanger unit at 85% porosity is discussed. The effect of the resonance frequency of air on the stack-heat exchanger sheets spacing and thickness and on the theoretical performance is discussed. The effect of the resonance frequency of air on the theoretical performance at 200 Hz, 300 Hz, and 400 Hz is discussed. The cooler shows better COP of 1.72 at 300 Hz for air and 1.53 at 400 Hz for helium. The theoretical results are compared with the DeltaEC software results. The DeltaEC predicts cooling power and COP of 347 W at 1.02 for helium and 224 W at 0.79 for air, respectively.

On the best coefficient of performance and specific heating or cooling power combination for adsorption refrigerators and heat pumps

The performance parameters of adsorption refrigerators or heat pumps are the coefficient of performance (COP) and the specific cooling power (SCP) or specific heating power (SHP), respectively. Higher COPs are associated with the longer cycle times required for more complete desorption and adsorption processes, resulting in a lower number of cycles per unit time and consequently in lower SCP or SHP, unless large masses of adsorbent material are used. The inverse situation occurs for shorter cycle times, associated with smaller COPs and higher SCP or SHP. This behavior leads to a relevant question: what is the combination of COP and SCP or SHP corresponding to the optimal performance of adsorption refrigerators or heat pumps? Although this question is recurrent in literature, its objective answer is still lacking. This work proposes an objective criterion to answer this question, setting the best balance between the COP and the SCP or SHP of adsorption refrigerators or heat pumps, as corresponding to the minimum unit cost of the obtained useful effect. The proposed criterion allows obtaining the cycle time that corresponds to the searched optimal performance. The dependence of the COP and the SCP or SHP on the cycle time can be obtained from numerical simulations for an adsorption system. Once these dependencies are known, it can be identified the cycle time leading to the minimum unit cost of the obtained useful effect, which corresponds the best balance between the COP and the SCP or SHP.

Investigation of stepwise porosity and perforated fins in finned tube adsorption bed for adsorption refrigeration

Adsorption refrigeration is a green refrigeration technology. The characteristics of its key component, the adsorption bed, directly affect the operational performance of the entire system. In this study, two novel types of structures, stepwise porosity and perforated fins, were applied to three types of conventional finned tube adsorption beds to improve heat and mass transfer. Using the finite element analysis method, the impacts of porosities and perforations were systematically evaluated to clarify the application range and development potential of this new technology. The results indicate that the overall performance of the system using a finned tube adsorption bed with an annular outer fin is better than that of a plate outer fin and annular inner fin. Stepwise porosity can help maintain the system coefficient of performance (COP) and reduce the degradation of the specific cooling power (SCP) when the finned tube adsorption bed is designed with a long fin or large fin spacing. The perforated fin structure improved the refrigeration performance of the finned tube adsorption bed. Stepwise perforation affects the values of the COP to some extent, but the variations in the value of the SCP are minor. Stepwise perforation combined with stepwise porosity might be a potential structure for further improving heat and mass transfer in the adsorption bed.

Energetic performance evaluation of an automotive CO2 air conditioning system with a dual-evaporator configuration

Inefficient performance of CO2 refrigerant in hot climates has become a major obstacle to its wide application in electric vehicles. In this paper, the vacant heating core in cooling mode was exploited to increase the heat transfer area of evaporator and improve system performance. With the aid of a validated evaporator model and an experimental test rig, performance improvements brought by this added area were evaluated. Results indicated that this area is not suggested to be directly added to cooling core. This necessitates a dual-evaporator (D-E) configuration. For case I (small CO2 pressure drop), the growth rate in heat transfer rate brought by D-E configuration is 19∼20% and less sensitive to parallel or series operation. Nevertheless, this growth rate for case II (large CO2 pressure drop) is greatly affected, 30.6∼32.6% for parallel operation and 7.5∼17.6% for series operation. Specifically, it is around 17.5% and 7.5∼13.6% for series cross-parallel and cross-counter arrangements, respectively. By comprehensive consideration, the cross-parallel arrangement is recommended to be adopted. Experimental results indicated that the cross-parallel D-E configuration greatly increases the evaporation temperature and exhibits a slight impact on optimum high pressure within the transcritical cycle. The enhancement in COP brought by this configuration is around 6∼12% without additional cost, and it rises with the decreased air flowrate through evaporator and air velocity through gas cooler and the increased ambient temperature. This indicates that this configuration is an effective and economical technology to alleviate the efficiency degradation issue of transcritical CO2 automotive air-conditioners.

Understanding airflow pattern and temperature distribution in domestic refrigerators – A review analyzing recent developments and bridging knowledge gaps

Refrigerators have become an essential appliance in every household, and they consume approximately 30% of total electricity among other domestic appliances such as clothes washers, dryers, and air conditioners. With the refrigerator’s comparatively high energy consumption compared with other appliances, existing research has mainly focused on improving the energy efficiency of refrigerators by changing the design of the compressor, heat exchanger, refrigerant, and insulation. However, previous studies have paid very little attention to the research and development of the temperature distribution in the refrigerator, which is a key parameter in determining energy consumption and food safety. Therefore, this review aims to present an overview of recent design developments to improve the temperature distribution and air circulation in domestic refrigerators, including static refrigerators and no-frost refrigerators. This review article discusses the various operation and design factors that can affect the air circulation and temperature uniformity of the refrigerator, including shelf arrangement, the compressor on/off cycle, thermostat settings, evaporator design, ambient conditions, door opening frequency, and product loading temperatures. Additionally, this review provides a summary of the advanced vapor compression cycle based refrigerators that are expected to provide better energy efficiency and independent temperature control in freezer and refrigerator compartments. This review elaborates on the significance of improving the performance of the domestic refrigerator in terms of temperature distribution and air circulation.

Magnetocaloric properties of La0.9Pr0.1Fe11.2Co0.7Si1.1 compound through direct measurements under cyclic magnetic fields up to 30 Hz

Direct measurements of the adiabatic temperature change (ΔTad) in cyclic magnetic fields with a frequency of up to 30 Hz in the La0.9Pr0.1Fe11.2Co0.7Si1.1 alloy were carried out. For this alloy, the magnetocaloric effect (MCE) under magnetic field change of 1.8 T is 2.8 K and the temperature hysteresis does not exceed 0.5 K. Under magnetic field change of 0.62 T with frequencies of up to 20 Hz, the MCE shows a weak frequency dependence (less than 5%), while under magnetic field change of 1.2 T the frequency dependence is clear pronounced. Long-term exposure to a low frequency cyclic magnetic field does not result in a change in the MCE value, while at frequencies more than 10 Hz noticeable degradation of the MCE is observed. The results of the study show that the upper limit of the operation of magnetic refrigerators can reach several tens of Hz.

Experimental investigations on the performance of a thermo-mechanical refrigeration system utilizing ultra-low temperature waste heat sources

Experimental studies that investigate the utilization of ultra-low temperature (between 48 °C and 120 °C) waste heat, which forms 25 % of the global unrecovered waste heat, to drive thermal cooling systems are rare. Thus, this study fills a significant gap in the literature by (i) experimentally evaluating the performance of a new full-scale thermo-mechanical refrigeration (TMR) system at ultra-low temperatures ranging from 50 °C to 85 °C, (ii) characterizing its operation with different commercial refrigerants, and (iii) identifying optimal operating conditions and working fluids for the investigated TMR system. An organic Rankine cycle (ORC), vapor compression cycle (VCC), and expander-compressor unit (ECU) make up the TMR system. To ensure its efficient operation, flexibility, and reliability, a full-scale ECU-based TMR system with a design capacity of 1 kW at a heat source temperature of 85 °C is built and put through a series of tests. Furthermore, the TMR system is tested with different commercial refrigerants (R134a, R410A, R407C) over a wide range of operating conditions of the power loop. The results reveal that the ECU-based TMR system can work with ultra-low temperatures of 65 °C with an energy efficiency of 5.92 % and COP of 2.36, for the ORC and VCC, respectively. At a heat source temperature of 85 °C, a condenser water temperature of 15 °C, and an evaporator water temperature of 33 °C, the energy efficiency of the ORC and COP of the VCC are increased to 9.85 % and 3.99, respectively. For the cooling quality, the TMR system shows a minimum evaporator temperature of −10 °C using R134a in both the power and cooling loop, which is improved to lower than −20 °C by using R407C in the cooling loop. The results presented herein will be beneficial to the development, design, and optimization of refrigeration and power systems that utilize low-temperature waste heat.

Hysteresis loss and field dependence of magnetic entropy change of Zn-doped Mn5Ge3 system

In this work, a series of Mn5Ge3-xZnx samples were prepared by the arc-melting method. The Rietveld structure refinement of the powder XRD spectrum was performed using the FullProf program. The lattice parameters and cell volume increase with the doping of Zn atoms. From the magnetization curve at 5 K, the compounds show a decreased magnetic moment of the Mn atom with increasing Zn content, resulting from mixing the 3d electronic state of Mn atoms and the 3d electronic state of Zn atoms. The small hysteresis loss and soft ferromagnetism of Mn5Ge3-xZnx indicate that it is suitable for magnetic refrigeration. Thermomagnetic M(T) curves show an increase in thermal hysteresis concurrent with increasing Zn concentration, which is verified by the DSC curve. It is found that the magnetic entropy change and effective magnetic moment decrease with the increase of Zn content, which can be attributable to the doping of Zn atoms resulting in the weakening of the exchange interaction between Mn-Mn atoms and the decrease of magnetic entropy change. In addition, the specific power-law relationships between the magnetic entropy change, the maximum magnetic entropy change, the relative cooling capacity, and the magnetic field of this system were determined, which provides a tool for evaluating the performance of the magnetic refrigerant in the entire magnetic field range. Finally, the specific heat was calculated by the magnetic entropy change obtained by the experiment, and the specific heat curve proves that the sample undergoes a second-order phase transition, consistent with the results of Arrott plots. The TC obtained by the specific heat -ΔCP−T curve is in good agreement with the TC obtained by the magnetic measurement, revealing that TC obtained by the specific heat is also an effective method.

Analysis on transient characteristics of air-cooled thermoelectric cooler in confined space with internal heat source

A transient model of the thermoelectric refrigerator working in a cooling space with an internal heat source is established. The influence of key parameters on the transient performance of the thermoelectric refrigerator under different working conditions is analyzed. The changes of the minimum cooling temperature and the cooling coefficient is analyzed, which were compared with different internal heat source power, input current and filling factor. The results show that the power of internal heat source has a significant impact on the cooling temperature and the time required for temperature stabilization. There are optimal working current and optimal filling coefficient which can make the cooling rate reach the maximum and the cooling space temperature reach the minimum respectively. The optimal filling factor increases with the power of the internal heat source.

Performance analysis of heat pipe-cooled two-stage thermoelectric air conditioner

A detailed model of heat pipe-cooled two-stage thermoelectric (TE) air conditioner is established. The performance is analysed comprehensively including the cooling power, coefficient of performance (COP), thermodynamic perfectibility and extreme temperature difference. The influences of key parameters including working current, distribution ratio of TE elements and heat pipe parameters are analysed by numerical simulation. The working current and the TE element number ratio are optimized for the maximum cooling power and the maximum COP respectively. The influences of the cross-sectional area, the length of the TE element and the temperature difference on the optimal variables and optimal performance is obtained. The results show the refrigeration performance of the TE air conditioner can be effectively improved by heat pipe cooling. The two-stage mode can effectively improve the refrigeration temperature difference. The extreme temperature difference can be improved from 60 K to 110 K.

Study on a direct-coupling thermoacoustic refrigerator using time-domain acoustic-electrical analogy method

Thermoacoustic refrigeration is a clean cooling technology with high reliability. In this study, a time-domain acoustic–electrical analogy (TDAEA) method is proposed and improved, then applied to explore the performance of a high-efficiency 2-stage looped direct-coupling heat-driven thermoacoustic refrigerator. The effectiveness of the method is verified by experiments. Transient evolutions of oscillating pressure and volume flow rate are first presented. System performance under different working gases is explored, and helium is chosen due to its much larger cooling power. The influences of cooling and ambient temperatures and cavity parameters on system performance are then investigated. The results show that a rise in ambient temperature leads to a dramatic decline in cooling power. Moreover, the influences of cavity parameters are complicated. When the diameter and length of the cavity are respectively 95 mm and 440 mm, the cooling power achieves a maximum of 3.65 kW with COP of 0.76; while with diameter and length reaching 90 mm and 360 mm, respectively, a peak COP of 0.82 with cooling power of 1.47 kW is obtained. Furthermore, a comparison between the presented direct-coupling system and a series-connection system is performed. The results show better performance of the direct-coupling system, which achieves a cooling power of 5.08 kW under air-conditioning case, 22.4 % higher than that of the series-connection system, implying its superiority in air-conditioning field for larger cooling capacity and more compact configuration. This study provides a new perspective for understanding ofthermoacoustic refrigerators.

Performance Assessment of Low Global Warming Potential Alternative Refrigerants

Global warming is the general increase in global temperature brought on by higher-than-normal concentrations of greenhouse gases. These gases trap heat waves as they approach the world and allow them to continue entering the atmosphere over time without being able to leave. This study used low global warming potential alternative refrigerants to reduce greenhouse gas emissions, in line with global efforts to phase out chlorinated fluids in order to preserve the ozone layer as a result of the Montreal Protocol. A software program called Cycle-D-Hx, which has a graphical user interface and a thermodynamic model of the refrigeration system, was used to evaluate how well household refrigerators working with various types of refrigerants performed. The model was validated using data from a household refrigerator charged with R134A. The performance of several low global warming potential alternative refrigerants, including R404A, R449A, R513A, and R452A, was then assessed using the model.
 The hydrofluoroolefin based R452A refrigerant is an alternative to R404A and R507 that is non-ozone depleting and has a low global warming potential. An azeotropic blend, R-513A is a drop-in replacement for R-134a in existing systems. Common hydrofluorocarbons and the new hydrofluoro-olefin molecule R1234yf are combined to form R449a, which is made up of R32 (24%), R125 (25%), R134a (26%), and R1234yf (25%). R513A, an aceotropic blend with no temperature glide, is composed of 44% R134a and 56% R1234yf.
 The simulation's findings demonstrate that R452A has a coefficient of performance 1.578, a zero potential for ozone depletion, a 0.5oC temperature glide for the evaporator and condenser and also a low potential for global warming unit count of 2140. Along with these thermodynamic and environmental qualities, R452A blend can take the place of R134A as a refrigerant because it is non-flammable and noncorrosive and will not corrode the metal parts of the compressor and evaporator of the refrigeration system.

Three-dimensional analysis of motile-microorganism and heat transportation of viscoelastic nanofluid with nth order chemical reaction subject to variable thermal conductivity

The most important condition of modern industrial activities is excellent refrigeration performance for conventional buildings. The Buongiorno relation assessment identifies nanofluid's thermal and mass efficiency, which inspires us to specify different properties of random motion and thermophoretic diffusion. Non-Newtonian nanofluids are used in a variety of fields, including thermal exchangers, solar liquid boiler, and heat control in vehicles. Nanoparticles can significantly enhance a fluid's thermal conductivity and heat transfer properties. This makes nanofluids attractive in cooling systems for electronic devices, such as computer chips and LED lights, and in various industrial applications where efficient heat transfer is important. The proposed thermos-electric system depends on nanomaterial heat flow, fractional volume of nanomaterial, density, and motile microorganisms. Because of their numerous applications, ferromagnetic nanoparticles have become extremely popular in biotechnology. Numerous mathematical and technical constraints are considered to generate more useful data. Using the shooting scheme, evaluating numerically by MATLAB function bvp4c to transform expressions. Some observations about the bio-convection procedure its different exclusive characteristics are elaborated in the literature. The graphs show how multiple flows influence non-dimensional quantities. The present theoretical model could be applied to engineering methods, heat transfer improvements, and thermal energy.

Refrigerator Performance With Natural Refrigerant (R1270) Double Pipe Heat Exchanger, Various Capillary Pipe Lengths

Refrigerator technology continues to develop towards a better and more efficient direction. Refrigerator must be given a touch of innovation to get the best performance. This study aims to obtain data on the performance of refrigerators with double pipe heat exchanger innovation and variations in the length of the capillary tube. The research method used is experimental. The experiment was carried out on a 1/6 PK refrigerator trainer, the ratio of the size of the double pipe heat exchanger was 1/4:1/2, and the variations in the length of the capillary pipe were 1.5m, 2m, 2.5m, and 2.75m. The diameter of the capillary tube is maintained at 0.028 inches. The initial refrigerant used is refrigerant R-134a, which is then retrofitted by the drop in substitute method by refrigerant R-1270 as the refrigerant being tested. The load used is 1.5L mineral water. The results showed that the use of 1.5 m capillary pipe and double pipe heat exchanger was able to increase the value of the refrigeration effect up to 49%, the value of work efficiency (CoP) increased by 22% compared to the refrigerator system using R-134a. Electric power consumption has decreased by up to 25%, thereby reducing the cost of electricity bills. This study has shown that the use of refrigerant R-1270 in a refrigerator with a double pipe heat exchanger and a long capillary tube with a diameter of 0.028 inches improves performance and saves electricity consumption.