Tube Rows Research Articles

Numerical research on structure and performance optimization of a pioneering water-cooled fully premixed gas-fired equipment

To meet ultra-low emissions, traditional diffused low-nitrogen gas combustion technologies are not effective or extremely laborious in controlling the emissions of NOx. Thus, this study innovatively proposes a water-cooled fully premixed gas combustion technology and explores its impact on pollutant emissions through numerical simulation. The effects of the burner inlet channel’s equivalent diameter (de), the relative positioning of two rows of buried tubes, and the burner type on combustion in the boiler are explored in-depth. As de decreases, a progressive reduction in NOx emissions is observed and an anti-backfiring effect is enhanced. Moreover, using a concave burner and placing buried tubes in the combustion chamber efficiently reduces the combustion temperature and thus NOx emissions. Finally, a ternary phase diagram is constructed to guide structural design optimization and clearly depicts the effect of Airflow channel width (SW), Dimensionless distance between the first row of buried tubes and the burner nozzle (D1), and Dimensionless longitudinal distance of buried tubes (D2) on NOx and CO emissions. Under the optimized structural condition, the water-cooled fully premixed gas combustion reveals great potential to synergistically control NOx emissions to as low as 11 mg/m3 and CO concentration to 10−6 mg/m3. This research provides valuable reference data for theoretical research and equipment design.

Thermodynamic performance of air-cooled seasonal cold energy storage for space cooling: A case study

With the improvement in people's living standards, there is a growing demand for cooling, making it urgent to develop a low-carbon and energy-efficient refrigeration system. Therefore, this paper proposes an air-cooled seasonal energy storage (ACSES) system. The heat transfer model of the system is constructed. The impact of relevant parameters on the system's cold storage performance was analyzed. The results show that larger glycol flow rates, windward velocity, number of tube passes and tube rows, and the volume ratio of ethylene glycol to water (VR) are beneficial for improving cold storage performance. However, excessively large parameters do not significantly enhance cold storage performance. The influence of ambient temperature on cold storage performance is greater than that of ice thickness. When VR is 0.02, the cold storage performance is relatively superior. To demonstrate the energy-saving performance of the system, the energy consumption saving rate (ECSR) indicator was proposed. The ECSR of the ACSES system is 72.75 %. The system can significantly conserve resources and reduce energy consumption.

Simulation study on the effect of liquid ammonia spray on the heat transfer performance of multiple heat exchange tubes

Abstract In this paper, aiming at the problems of low heat transfer efficiency and uneven heat transfer of heat exchange tubes in refrigeration and air conditioning chillers, a liquid ammonia spray cooling method is proposed, and a flow and heat transfer model is established. The distribution of refrigerant droplets in the fluid domain and the heat transfer on the surface of the heat exchange tube are simulated under different spray speeds, spray directions, and double nozzle sprays. The results show that with the increase of spray velocity, the heat transfer performance of heat exchange tubes decreases first and then increases. The effect of spray velocity on the heat transfer performance of each row of heat exchange tubes is not consistent. The farther away it is from the nozzle, the greater the speed corresponding to the peak value of the heat transfer performance improvement of the heat exchange tube will be; the spray direction (gravity) has little influence on the heat transfer performance of the heat exchange tube, which is within 5.1%. Compared with single-nozzle spray, double-nozzle spray greatly improves the heat transfer performance of multi-row heat exchange tubes.

Experimental study on the scaling law of the heat exchange tube surface in the process of low-temperature single-effect distillation of high-mineralized mine water

High-mineralized mine water, due to its characteristics such as high mineralization degree, will have scaling phenomena on the surface of the heat exchange tube during the desalination treatment process, resulting in a reduction in the water production efficiency of the equipment and affecting the normal operation. To reduce the cost of water production and improve the service life of distillation equipment, this paper independently designs and builds a low-temperature single-effect distillation high-mineralized mine water experimental system to study the influence of operating parameters (temperature, spray density, concentration ratio, and system pressure) on the scaling law on the surface of the heat exchange tube. The distribution and characteristics of scale deposits on the surface of the heat exchange tube are analyzed through the growth rate and microscopic morphology of the scale deposit. The results indicate that the scaling on the surface of the titanium plate is mainly in the needle-like and rod-like morphology of CaCO3 aragonite, and a small amount of CaSO4 and calcite are generated with the increase of temperature. It was found that within the range of spray density from 0.0509 kg/(m·s) to 0.0625 kg/(m·s), concentration ratio from 2.3 to 2.7, and system pressure at 36.3 kPa, it is beneficial to the evaporation heat transfer of the heat exchange tube and the reduction of scaling generation. At the same time, it is found that the scaling of the first row of heat exchange tubes is mainly within the range of circumferential angle from 0 to 100 degrees, and the scaling of the second row and the third row of heat exchange tubes is mainly within the range of circumferential angle from 110 to 170 degrees. The research results of this paper provide support for the design and operation of the low-temperature multi-effect treatment system for mine water in engineering, promote the process of zero discharge of high-mineralized mine water in Xinjiang, China, and improve the resource utilization rate of high-mineralized mine water.

A simplified numerical method based on anisotropic porous media model for the precooler of the hypersonic precooled engine

The precooler is a key component of hypersonic precooled engine, and its actual structural have a high anisotropy in the axial, circumferential, and radial direction. Considering the non-uniform flow inside the precooler is crucial to study the flow and heat transfer characteristics of the precooler. The previous simplified method for the precooler has not fully considered the flow non-uniformity of the axial, radial and circumferential direction. In this paper, a simplified numerical method based on anisotropic porous media model for the precooler was proposed. The unique aspect of this method is the integration of anisotropic surface porosity of porous media model with the zero-dimensional heat transfer model. In addition, the influence of key structural parameters on the flow and heat transfer characteristics of precooler was studied. It is found that as the tube transverse pitch increases from 2 to 3.5, the total flow rate increases by 11%, and the heat exchange rate decreases by 25%. As the number of tube rows increases from 7 to 13, the heat exchange rate increases by 22%, but the total pressure loss coefficient increases from 0.046 to 0.082. In addition, the decrease of inner diameter of the precooler improves the heat exchange rate, but reduces the flow capacity of the precooler. These results indicate that the simplified numerical method is capable of simulating the behavior of precooler and provides some guidance on the design of precooler.

Numerical investigation on ash accumulation characteristics of serrated spiral finned tube heat exchanger in waste heat utilization

In this study, a comprehensive loose fouling model is established to investigate the fouling characteristics of fly ash on serrated spiral finned tube heat exchangers. This model considers the energy change during particle collision, the velocity change after particle rebound and slip, and the amplification of fouling time under mixed particle sizes. The results show that the fouling position, morphology, and height obtained by the theoretical model agree well with the experiments. Besides, the serrated spiral fin is the main fouling position due to its high fin ratio and the strong disturbance effect. The 5 μm particles have the highest deposition rate, and fine particles tend to adhere to the second row of finned tubes due to the consumption of initial kinetic energy by the first row. With an increase in fin height by 6 mm, the deposition rate only increases by 1.2 %, while an increase in sawtooth height by 5 mm results in a deposition rate increase of 14.3 %. When the flue gas velocity is less than 7 m/s, finned tubes arranged in a staggered configuration provide the best combination of heat transfer, flow resistance, and anti-ash accumulation performance.

Optimization strategies for the design of pre-cooler based on the synergistic air-breathing rocket engine

A foundation for the engineering of pre-coolers is provided to understand the flow and heat transfer characteristics of air pre-coolers. Using the pre-cooler in the combustor of the Synergistic Air-Breathing Rocket Engine (SABRE) as the research object and selecting the smallest periodic unit of the model, numerical methods were adopted to study the flow field, outlet temperature, total pressure loss, heat transfer coefficient, and heat transfer power under the different number of tube rows, pitch, and helium/air heat capacity ratios. The number of tube rows increased from 7 to 15, the tube pitch increased from 1.5 mm to 3.5 mm, and the helium/air capacity ratio increased from 1.06 to 1.64. The results show that increasing the tube pitch reduces the outlet velocity and decreases the heat exchange efficiency, but the total pressure loss is reduced. Increasing the number of tube rows results in a linear increase in total pressure loss, but the heat exchange efficiency also increases. The increasing trend slows down when the number of tube rows exceeds 11. An increase in the heat capacity ratio can reduce the total pressure loss, increase the heat exchange power, and increase the amount of helium required. It can provide a reliable technical foundation for the practical engineering design of similar pre-coolers.

Numerical study on lead–bismuth cross-flow induced vibration in the elastic tube bundle

The physical properties of liquid lead–bismuth eutectic fluid are quite different from that of water or air. It needs to be verified whether the cross-flow vibration mechanism and the empirical prediction model of fluidelastic instability in conventional media are applicable to lead–bismuth. In this work, for an in-line elastic tube bundle with pitch ratio P/D = 1.5, the flow excitation of lead–bismuth at 200 °C is studied and compared with that of water in uncoupled flow field. Then, two cases of lead–bismuth flow-induced vibration with different mass-damping parameters are simulated and studied by fully coupled numerical simulation considering fluid viscous damping. The tube bundle experiences the process from turbulence-induced vibration in low flow velocity to fluidelastic instability in high velocity. The results of flow excitation show that the pressure coefficient distribution of the front row tube in lead–bismuth is basically consistent with that in water, while the inconsistency of the pressure coefficient distribution for the back row tube is caused by the bi-stable deflective flow. The results of lead–bismuth flow-induced vibration show that, in fluidelastic instability, the vibration of tube bundle and the vortex shed from tube bundle are dominated by the frequency close to the first wet modal frequency of tube bundle. The different deflective directions of lead–bismuth and water, caused by bi-stable characters, have less effect on the onset of fluidelastic instability. The instability points of lead–bismuth agree with the experimental results of other media and the Connors prediction model considering fluid viscous damping. The prediction model is suggested to predict the onset of fluidelastic instability induced by lead–bismuth cross-flow in the tube bundle.

Numerical analysis of the heat transfer and pressure drop of a wavy fin and Kammtail tube condenser: An investigative study

The aim of this study was to numerically investigate the factors affecting the air-side performance of an innovative condenser for a domestic refrigerator. Novel condenser with a smooth Kammtail tube form was investigated due to delaying flow separation. For the first time in the literature, the kammtail form was used instead of round or ellipse geometry in a finned tube heat exchanger, and the advantages of this form was demonstrated both experimentally and numerically. This study incorporated design parameters such as air velocity (0.5, 0.7, 1 m/s), number of tube rows (4 or 5), tube arrangement (inline, staggered), fin pitches (5, 7, 10, 5–7, 5–10, 7–10 mm), and fin arrangement (homogeneous or hybrid). The findings indicated that, for identical fin types and fin surface areas, the proposed Kammtail shape of 3 × 6 mm exhibited 19% lower pressure drop and 9% higher heat-transfer coefficient compared to the original circular tube profile. Furthermore, decreasing the fin pitches resulted in a 32.9–97% increase in static pressure drop, while the heat-transfer coefficient decreased by about 4.7–11.7%. The examination of two new designs revealed a marked reduction of 7–20.4% in the static pressure drop, a decline in air flow rate of 30%, an increase in heat transfer of 5.6–12.2%, and a corresponding decrease in the volume of the condenser of 20%. The numerical results of this study are in good agreement with experimental results, with deviations of less than 10%.

A numerical study on convective condensation of flue gas in tubular heat exchangers

The accurate calculation of heat transfer process in the condensing heat exchanger plays a crucial role in the waste heat recovery. In this study, the convective-condensation heat transfer process in a condensing heat exchanger with five small heat exchangers is analyzed through utilizing a new numerical simulation model. The method that loads the latent heat of condensation as the heat generation rate is adopted. Under the two working conditions in this study, the deviations of outlet temperature between numerical and experimental results are 1.3 and 2.2 K, respectively, while the deviations of total condensate water flow are 8.5 % and 5.5 %, respectively. Under the drier working condition, the average temperature reduction (5.8 K) per row of tubes in the first small heat exchanger where no condensation occurs is higher than that (2.6 K) in the third small heat exchanger where the water vapor starts to condense. It indicates that the release of latent heat of condensation slows down the cooling rate of the flue gas. In the small heat exchanger where the water vapor starts to condense, the amount of condensate water on the wall of each row of tubes increases first and then decreases slowly along the flow direction of the flue gas.

Performance comparison of inline and staggered integrally-molded spiral finned tubes for low-carbon emissions

The combined flue gas cooler with integrally-molded spiral finned (IMSF) tubes, which combines in-line and staggered tube bundles to leverage the performance advantages of different arrangement modes, has been proposed in this paper to simultaneously achieve heat transfer enhancement, ash deposition prevention, and wear resistance. The comprehensive performance including thermal–hydraulic, ash deposition, and wear performance of in-line and staggered IMSF tubes has not been reported and has been investigated with a multi-field coupled numerical model in this paper. Results show that for inline tubes, increasing the transverse pitch (PT) can reduce ash deposition and wear with slightly decrease in the thermal–hydraulic performance and increasing the longitudinal pitch (PL) can improve the thermal–hydraulic performance, with a significant increase in ash deposition when PL reaches to120mm, while for staggered tubes, decreasing the PT can enhance the thermal–hydraulic performance and reduce wear, with a sharp deterioration in ash deposition when the PT reaches 80 mm, and increasing the PL can decrease wear and has a minor impact on the thermal–hydraulic and ash deposition performance. Also, in the design of combined flue gas coolers, inline tubes should be placed at the front and two rows of dummy tubes placed before the inline tubes, and a larger PT and a moderate PL should be adopted to effectively reduces the overall tubes' wear and ash deposition; staggered tubes should be placed at the rear with an appropriate PT and a larger PL, enabling the full utilization of their excellent thermal–hydraulic performance while avoiding severe wear. This work can provide theoretical guidance and reference for the design and optimization of combined flue gas coolers to promote low-carbon emissions.

SRANS Simulation on a Helical-Segmented Finned Tube Bank

A numerical simulation on a six-row helical-segmented finned tube in a staggered layout is performed with the Reynolds Averaged Navier-Stokes (RANS) approach. The turbulence effect is represented with the k-ε RNG model, and a fixed temperature in each tube row considers the inside fluid temperature. The tube bank is represented by a small finned tube bank and a single interacted module. The small finned tube bank considers symmetry conditions on the sides of the computational domain. The single interacted module considers periodic boundary conditions for velocity, pressure, and temperature. Both simulations are compared to develop the basis of complex simulations such as repetitive finned tube modules. Average values on parallel planes to the streamwise direction for velocities, pressures, and temperatures are compared in both simulations. The comparative analyses show deviations lower than 11% for the velocity field, 12% for the pressure field, and 10% single for the temperature field. Therefore, results show an appropriate flow representation with periodic boundary conditions.

Numerical investigation on the heat transfer of air/helium precooler for air-breathing pre-cooled engine

Installing a precooler behind the intake is an effective approach for hypersonic air-breathing pre-cooled engine to cool the hot incoming air. Synergetic air-breathing rocket engine is a revolutionary hypersonic air-breathing pre-cooled engine with complex thermodynamic cycle i.e. air cycle, helium cycle. Air/helium precooler is a key component and its configuration and operating condition have great effect on the performance characteristics of air-breathing pre-cooled engine. Thus, the minimum periodic flow and heat transfer model of the precooler are established. The effects of key parameters on the heat transfer performance of precooler are numerically studied. The results indicate that: when the tube row number increases from 7 to 15, the average heat transfer coefficient of air side decreases by 57%, the heat exchange rate increases by 19%, and effectiveness increases by 18.4%. The tube transverse pitch can enhance the heat transfer coefficient of air and helium side, while the heat exchange rate decreases by 33 % when the tube transverse pitch increases from 1.5 to 3.5. The helium inlet velocity can improve the heat transfer performance of precooler and reduce the flow resistance of air side.

Multi-Objective Finned-Tube Heat Exchanger Optimization Using a Genetic Algorithm

Heat exchangers are a significant component in many industries, particularly in energy conversion systems. The design of heat exchangers itself is a complex process because it involves experience-based decisions, numerous variables and parameters, and some of them are competing with each other. Genetic Algorithms (GAs) are one of the first evolutionary algorithms which remains one of the most extensively used non-linear optimization methods today. This study explores the implementation of Non-Dominated Sorting Genetic Algorithm II (NSGA-II) for thermal design and optimization of a finned-tube heat exchanger. The chosen objective functions were minimizing the heat exchanger volume and minimizing the air side pressure drop. The decision variables for the design were tube outer diameter, number of tube rows, fin pitch, unit height, and unit width. The calculated parameters and estimated cost of both preliminary design and optimized design were also compared. The optimized design offered a bigger alternative design while meeting all the constraints according to standards and industrial needs. The optimization reduced annualized operational and maintenance costs by 228% and lowered air pressure drop by 413% with bigger heat exchanger volume of 12% compared to the preliminary design.

Experimental investigation of water vapor condensation from flue gas in different rows of a heat exchanger model

Condensing heat exchangers (HE) are used in many applications because of their usability with different fluids and a wide operating range in terms of pressure, temperature and power. Despite that, the thermal design of condensing heat exchangers is still not optimized, due to the complexity of the condensation process and lack of related research.This paper presents results of experimental investigations of biofuel flue gas water vapor condensation on vertical tubes in different rows of a tube bundle in a crossflow. The effects of water vapor mass fraction, inlet flue gas temperature and the Reynolds number on heat transfer when the inlet cooling water temperature and flow rate are constant were analyzed. The results obtained showed that the main parameters which had the most influence on the condensation process were the water vapor mass fraction in the flue gas and its temperature at the inlet to the test section. In the range of inlet flue gas Reynolds numbers investigated, the Re effect on heat transfer was not as significant as the effect of the parameters indicated above. However, the Re number had some influence on the heat transfer variation along the inline tube bundle. A comparison of the average Nu number in the case of dry air with the experimentally determined average Nu number, even with low condensable gas mass fraction (6 %), showed that it increased considerably. A correlation was proposed, which helps to determine the average Nu number for the heat exchanger in the range of experiments performed.

Spray evaporation of R1234ze(E)/POE-68 refrigerant-oil mixture on enhanced tube bundles

Lubricating oil is used in compressors of vapor compression-based refrigeration systems. The oil that escapes from the compressors inevitably circulates in the heat exchangers, affecting their thermal performances. This paper presents a comprehensive study on the impact of lubricating oil on the heat transfer performance of spray evaporator tube bundles used in air conditioning and refrigeration systems. The research includes valuable data on the heat transfer coefficient of tube bundles when subjected to refrigerant and lubricant mixtures of R134a (HFC) and R1234ze(E) (HFO) with synthetic polyolester (POE) lubricant. The investigation delves into the influence of three crucial factors: heat flux, oil circulation ratio (OCR), and saturation temperature. The saturation temperature was examined across a range of −6.7 to 10 °C (20–50 °F), while the heat flux was varied from 6 kW/m2 to 17 kW/m2. OCR was controlled at 1.2 %. The effects of oil on spray evaporation of R1234ze(E)/POE mixture on enhanced tube bundle was studied by varying tube surface structure and bundle layout, that is, square and triangular configurations.The bundle heat transfer coefficient decreased by at least 10 % when lubricant was present in the mixture but, in some cases, varied by 50 % or more compared to the performances with refrigerant only (i.e., no lubricant). The data suggested that the oil penalized the heat transfer coefficient of the bottom tube rows of the bundle, which in many conditions, starved and experienced a partial-dry out state. Externally enhanced boiling-type tubes were more sensitive to the presence of oil than externally enhanced condenser-type tubes.

Experimental study on the external resistance of vertical tube indirect evaporative coolers

To address the calculating difficulty of external resistance of vertical tube in the widely used indirect evaporative coolers, this paper experimentally investigates the influencing factors of the tube external resistance and develops calculation formula for tube external resistance. An experimental setup was constructed to test the external resistance of different numbers of tube rows at wind speeds of 1 m/s, 1.5 m/s, 2 m/s, 2.5 m/s, and 3 m/s. A specific vertical tube indirect evaporative cooler with a tube diameter of 25 mm, tube-to-tube center distance of 35 mm, and row-to-row center distance of 30 mm was studied. It was found that the tube external resistance of the studied cases is mainly affected by the face wind speed and the number of tube rows. Based on the response surface method (RSM), a formula for calculating the tube external resistance was fitted using the measured data, which provides guidance for engineering applications of vertical tube type indirect evaporative coolers.

The interaction between cross-flow induced vibration and convection heat transfer in tube bundle at subcritical Reynolds number

This work numerically investigates the interaction between flow-induced vibration (FIV) and forced convection heat transfer in tube bundle with a pitch ratio of 1.5 at subcritical Reynolds number (Re = 5 × 103-3 × 104). The range of reduced velocity is 0.53 ≤ Vr ≤ 2.71. The mass-damping parameter of coupling system is 0.07. The three-dimensional refined FIV simulation considering fluid viscous damping has been validated by the literature experiment to capture three continuous FIV mechanisms, namely turbulence-induced vibration, vortex-induced resonance and fluidelastic instability. The heat transfer and pressure drop in tube bundle are validated by the experiment. The coupling of Navier-Stokes equations, energy equations and vibration equations is solved by under-relaxation algorithm. The results of vibration response, the change of damping for the coupling system, flow field and temperature field, heat transfer and pressure drop are presented and delineated in this paper. The results show that for the low velocity turbulence-induced vibration, the interaction between FIV and flow heat transfer is negligible due to the weak fluid–solid interaction. In vortex-induced resonance region, the wall heating makes each row tube be out of phase by affecting the vortex shedding and reduces the positive feedback of resonance, which reduces the amplitude. The wall heating reduces the damping of coupling system, which causes an earlier transition from vortex-induced resonance to fluidelastic instability and a faster increase of amplitude in fluidelastic instability. In both vortex-induced resonance and fluidelastic instability, the vibration of tube bundle dominates the vortex shedding by the natural frequency, and further dominates the change of heat transfer. The best performance of enhanced heat transfer induced by FIV is located in vortex-induced resonance region, in which the time–space averaged Nusselt number is increased by 8.83%. Due to the redistribution of flow field and the elimination of deflective flow pattern, compared with vortex-induced resonance, the increasing ratio of heat transfer induced by FIV is lower and the increasing ratio of pressure drop induced by FIV is higher in the fluidelastic instability.

Effect of pulsation parameters on the spatial and temporal variation of flow and heat transfer characteristics in liquid metal cross flow the in-line tube bundle

Liquid metal has a broad application prospect in tube bundle heat exchangers because of its excellent thermal conductivity. However, conventional in-line tube bundle arrangements often exhibit limited secondary flow, so new methods are urgently needed to improve heat transfer. The topic of this paper is to combine two methods, liquid metal cross flow tube bundle and pulsating flow, to improve the heat transfer performance in-line tube bundles. Firstly, the applicability of the model was validated through experimental data from existing literature, encompassing overall flow dynamics, heat transfer performance, and circumferential pressure distribution around the tubes. Subsequently, numerical simulations are conducted involving liquid metal cross flow in-line tube bundles at varying pulsating frequencies, amplitudes, and Reynolds numbers. Circumferential pressure distributions and temperature profiles for individual tubes were analyzed and compared. The amplitude of reduction in thermal resistance compared to the no-oscillation condition increases gradually from a minimum of 8 % in the first row to a maximum of 40 % in the third row, while the reduction in the rear row of tubes is similar to that of the third row. Remarkably, a reversal in the trend of thermal resistance for the first three rows of tubes under pulsating flow were observed, contrasting conventional flow except for the case with an amplitude of 0.1. By analyzing the local transient flow field distribution near single tube and the corresponding circumferential heat transfer performance, the influence of the vortex evolution characteristics on the heat transfer performance at different phases of the pulsating velocity is revealed, which transient Nu is up to three times that of flow with no pulsating. Finally, a series of coherence analyses reveal that as frequency rises, turbulence exhibits a richer spectrum of small-scale vortex structures, intricately linked to enhanced energy cascade efficiency. Amplitude augmentation intensifies velocity fluctuations, particularly at high amplitudes, resulting in substantial energy peak amplification. The integrated heat transfer performance PEC factor varies in the range of 1.25 to 1.51 for all the conditions simulated in this paper, which indicates that the liquid metal coupled pulsating flow approach can significantly increase the comprehensive performance of the tube bundle heat exchangers. These findings hold significant promise for advancing heat exchanger design and enhancing thermal efficiency, with implications for various engineering applications.

Experimental study on performance improvement of a household refrigerator with a flying-wing evaporator

In order to improve the performance of a household refrigerator, a flying-wing evaporator (FWE) is to replace the original finned tube evaporator (FTE). Different from the FTE, the fins of the FWE are formed directly on the tube by shoveling movement. Therefore, the FWE has high efficient heat transfer performance due to no thermal contact resistance between the tubes and the fins. According to different combinations of fin pitch and number of tube rows, three different structures of FWE are designed and tested in comparison with the original FTE on a double-door household refrigerator. The results show that the FWE shortens the cooling duration by 0.32 h (9.3%) and reduces the annual energy consumption by 4.28% with a 25% reduction in volume and a 13.5% reduction in refrigerant charge. This study proves that applying a FWE into a household refrigerator instead of the traditional FTE is one of the effective ways to decrease the volume of evaporator, reduce the energy consumption of refrigerator and enhance the effect of food preservation.