Effects Of Different Operating Conditions Research Articles

Performance analysis and thermal comfort evaluation of a CO2 transcritical air-conditioning system for cabin thermal management of electric vehicles

This study investigates the effects of different operating conditions on system performance and optimal discharge pressure by establishing a numerical model of CO2 cabin thermal management system and validating the model with experimental data. Besides, two different optimal discharge pressure formulas are attained based on different parameters. It is found that the multi-parameter formula is more accurate than the other with a maximum deviation of 2.64%. Then, the control strategy is designed based on this formula to investigate the coupled effects of thermal comfort and economical performance under different driving patterns and different ambient temperatures. The elevation of PMV indicator can weaken the declining rate of power and energy consumption, enhance the driving range and reduce annual operation cost in cooling mode (AOCc) of vehicle. The boundary of thermal comfort zone (PMV = 0.5) exhibits excellent economical efficiency due to its higher growth rate of driving range (6.3%) and reduction rate of AOCc (7.9%) from 0 to 0.5 PMV at the ambient temperature of 35 °C. And this improvement is more prominent under higher ambient temperature.

Enhancement of CO2 removal from flue gas in an oscillatory baffled column using potassium carbonate solution

One of the efficient methods for reducing CO2 emissions from flue gas streams in oil refineries and power plants is the CO2absorption process using alkali solution. Potassium carbonate (K2CO3) solution, as CO2 absorbent, was used in the present study due to its high CO2 absorption capacity. However, K2CO3 has a drawback which is represented by its slow reaction with CO2. To overcome this issue, an oscillatory baffled column (OBC) was utilized as a contactor to maintain a high degree of mixing in the CO2 absorption system and thereby increasing the reaction rate between K2CO3 and CO2 as well as enhancing the mass transfer rate. In this study the effect of different operation conditions of the process namely; inlet flue gas flow rate (15 % (v/v) CO2 balanced with N2) and oscillation conditions on CO2 absorption in a semi-batch OBC were investigated. The experiments were performed with range of modified Reynolds Number of Oscillation (Reo′ = 0⎼1450) and aeration rates (0⎼1 vvm) using K2CO3 (100 g/L, 0.72 M)0.1.8–3.5-fold of enhancement of CO2 absorption rates was achieved by using OBC with respect to that obtained by baffled column (BC) (only baffles without oscillation) and plane bubble column (PBC) (without baffles and oscillation), respectively.The use of K₂CO₃ as a solvent in an oscillating reactor (OBR) to remove CO₂ represents a new method due to the high reactivity of K₂CO₃ with CO₂, forming stable bicarbonate and carbonate compounds. OBR's enhanced mixing capabilities improve mass transfer rates and reaction efficiency, allowing for more effective CO2 capture compared to conventional reactors. This combination leverages the strengths of both the chemical reactivity of K₂CO₃ and the mechanical benefits of OBR, potentially leading to more efficient and scalable CO2 removal processes.

Modeling of a solution polymerization reactor operating in semi-batch mode for polymethyl methacrylate production

The severe consequences of thermal runaways, make process optimization of paramount importance for free radical polymerization reactors, in order to maximize in an integrated way their safety and productivity. Generally, this optimization is performed by simulation, for the sake of safety and cost. Today, the literature contains several models of free radical polymerization reactors in general; and methyl methacrylate (MMA) polymerization reactors, in particular. Although, MMA polymerization is commonly performed in semi-batch reactors at industrial level, most of the available models focus on batch reactors; while, the semi-batch reactor models are much scarcer. In this work, a model of a MMA solution polymerization batch reactor was modified in order to generalize it to semi-batch operation. The developed semi-batch model was used here for studying the effect of different operation conditions (feeding flow rate, initiator load, monomer initial load, and reactor temperature) on the quality characteristics of the produced polymer and on the safety and productivity of the polymerization reactor. The developed model can be used to optimize the operation conditions of a semi-batch reactor so that the final product quality meets the application requirements, while maintaining the reactor within its safe-operation envelope, and maximizing its productivity.

A two-dimensional cellular automaton-finite difference (CA-FD) model for lithium dendrite simulation

The non-uniform lithium deposition behavior on the negative electrode during the charging process in lithium metal batteries leads to serious safety hazards in practical applications. The phase field (PF) method is the most commonly used to simulate the evolution of the microscopic morphology of lithium dendrite, which is computationally expensive due to the coupled partial differential equations (PDEs). Compared to PF, cellular automaton (CA) can efficiently process the evolution of solid-liquid interface with the neighbor configuration and interaction rules. In this paper, a two-dimensional cellular automaton-finite difference (CA-FD) model based on the decentered square algorithm (DSCA) is established. In this model, the growth of the moving solid-phase interface is described by CA, and the distribution of concentration and electric potential is solved by FD, therefore achieving a higher computation efficiency. During the modeling process, it has been verified that DSCA is more favorable to simulate the preferential growth of lithium dendrite tips than Neumann neighbors and Moore neighbors. Based on this model, the effect of different operating conditions of the lithium metal battery on the growth of lithium dendrites is investigated. The simulation results indicate that an increase in either the interfacial overpotential or the exchange current density accelerates the growth of lithium dendrites, in addition, more side branches are generated under higher overpotential. Therefore, low-rate charging mode is recommended in lithium metal battery to inhibit the growth of lithium dendrite.

A new empirical mass flow correlation and mass flow rate characteristics of R600a through novel rotary-baffle curved-channel electronic expansion valve

The novel rotary-baffle curved-channel electronic expansion valve (RBCC-EEV) has appeared in industry to replace a capillary tube as the variable expansion device in household refrigerators. However, due to the structure differences between the RBCC-EEV and the traditional orifice-type EEV, the previous empirical mass flow correlation inapplicable. In this paper, a new empirical correlation is proposed based on the structure and regulation principle of the novel RBCC-EEV, and the effects of different operating conditions on the mass flow rate of R600a flowing through two different RBCC-EEVs are experimentally investigated. The new empirical correlation introduces a centrifugal force coefficient and a variable length coefficient to represent the effect of asymmetric cavitation phenomenon and super-linear mass flow rate characteristics. The experimental results show a rise in the mass flow rate with increasing inlet pressure, inlet subcooling and opening ratio. Under the test range, the flow pattern of R600a flowing through the RBCC-EEV is chocked flow. Moreover, the proposed new empirical mass flow correlation agrees well with the experimental data. For 95.7 % of the prediction value, the relative deviation is below 15 %, while 89.0 % exhibit a relative deviation less than 10 %. The average deviation and standard deviation stand at 6.52 % and 4.56 %, respectively.

A potential-driven FeMnOx/CNTs film electrode for efficient extraction of WO42- via electrochemical coordination and inner-sphere complexation

A film electrode materials of iron-manganese oxide composite carbon nanotubes (FeMnOx/CNTs) with dual adsorption sites was obtained by a co-precipitation method, which exhibited excellent selectivity of WO42- in an electrochemically switched ion exchange (ESIX) system. The main components of FeMnOx are MnOx and Fe(OH)3. In FeMnOx/CNTs composite film, Fe(OH)3 with abundant hydroxyl functional groups on its surface improved the ion storage capacity, while MnOx served as the main selective separation material to selectively adsorb the WO42-. A scalable ESIX pilot system was also designed to examine the effect of different operating conditions on system performance. The W(Ⅵ) adsorption capacity was as high as 187.76 mg/g and the separation factor of W/Mo was 21.03. Combining experimental characterization and results, it was confirmed that the highly efficient selective extraction of WO42- in neutral solution should be derived from the dual-site (i.e., electrochemical coordination sites on MnOx and electrochemically induced inner-sphere complexation sites on Fe(OH)3) adsorption. Hence, it is believed that such a novel electroactive FeMnOx/CNTs film electrode with dual adsorption sites could be a promising candidate for industrialized tungsten-molybdenum separation by ESIX technology.

Evaluation of industrial performance of a new three phase fluidized bed flotation column-Based on product size characterization

There are still a large number of minerals processed by flotation every year, so it is extremely important to improve the flotation efficiency in industrial production. This study established an experimental test platform for new three-phase fluidized bed flotation column (TFC). The effects of different operating conditions and equipment parameters (apparent gas velocity, apparent liquid velocity, and filling height) on separation effect of coal slime were investigated. Relationship between turbulence intensity inside TFC and the flotation effect of coal slime with different particle sizes was analyzed. Results show that turbulence intensity in fluidized environment can be influenced by adjusting operating conditions to increase the probability of adhesion and collision of fine-grained particles with air bubbles. Differences of particle size distribution in the radial and axial directions of TFC are influenced by settling velocity. Increasing circulation volume can increase residence time of particles in flotation process. Micro and nano bubbles have excellent characteristics which are beneficial to particle collision and adhesion. By adjusting the parameters, it can meet needs of mineral separation and mineralization environment and realize effective recovery of slime with different particle sizes. This study was conducted by analyzing the flotation of fine particles by TFC during industrial platform testing. By evaluating the industrial performance of TFC, it provides a reference for future industrial large-scale applications.

Numerical simulation of ash deposition behavior in radiant syngas cooler coupled with impact surface temperature

Radiant syngas cooler (RSC) is a crucial heat recovery device for entrained-flow coal gasification technology. However, ash deposition in an RSC can severely affect operating efficiency and safety. An ash deposition model coupled with the impact surface temperature was established based on the ash particle deposition morphology. The effects of different operating conditions on ash deposition characteristics are discussed. The simulated data agreed well with the industrial data. The results indicate that ash particles were primarily deposited in the collision deposition zone. The maximum deposition thickness of radiation screen and cylinder membrane wall is 9.82 mm and 1.88 mm, respectively. The ash deposition hindered heat transfer process and the highest heat flux was observed in the middle part of the RSC. Ash deposition around 5.3 m increases significantly with an increase in the inlet syngas temperature. Increasing the load increased probability of ash particle collision and the area of influence.

Treatment efficiency and recovery in sand filters for on-site wastewater treatment: Column studies and reactive modelling

This study examined the adsorption capacity and treatment efficiency of sand filters in on-site treatment systems for cold climate regions. The effects of different operating conditions, porosity and kinetics parameters were investigated in column experiments and COMSOL Multiphysics® modelling, to comprehensively reveal the mechanisms and optimize treatment efficiency of nitrogen (N) and phosphorus (P) removal in a field tidal flow constructed wetland (TFCW), treating effluent from a package treatment plant with P filter material. The results from column experiments with sand showed that Total-P adsorption rate was dependent on feed water quality (Septic tank >0.77 ± 0.06 g kg−1; Biotreatment >0.41 ± 0.07 g kg−1; Reactive material Polonite® <0.18 ± 0.07 g kg−1). In the field TFCW trial, Total-P adsorption in the top layer (>1.42 ± 0.55 g kg−1) and middle layer (>1.06 ± 0.51 g kg−1) was twice that in laboratory columns, due to strong interaction with the air-water interface and use of fluctuated domestic wastewater solutions. The breakthrough curve (BTCs) of the coarse sand matched the physical behaviour of tracer electrical conductivity (EC) in effluent from the sand column experiments. The modelling results demonstrated that high filter porosity and low hydraulic load were significant factors for optimal removal of NH4–N, Total-N, PO4–P, Total- P in the top layer (>99.95 ± 0.03 %, 44.37 ± 28.75%, 70.89 ± 28.30%, 76.18 ± 20.3%), middle layer (>98.94 ± 1.77%, 18.23 ± 23.04%, 76.62 ± 28.73%, 65.40 ± 31.85%) and deep layer (>99.99 ± 0.02%, 65.50 ± 20.64%, 75.53 ± 23.16%, 41.54 ± 28.81%) in the TFCW system, respectively. The results show that on-site wastewater treatment in cold climate TFCW can be applied as a technology to polish effluent from a three-step pretreatment system. However, hydraulic optimization is an important factor for the design of the TFCW to receive a successful long-term operating system.

Study on magnetostrictive properties of oriented silicon steel sheet under different working conditions

Accurate measurement of magnetostriction is the basis for calculating the vibration of silicon steel laminated core. In this paper, a laser magnetostriction measurement system (MST500) is used to study the magnetostriction characteristics of silicon steel under sinusoidal, third harmonic, and DC bias magnetization. The magnetostrictive butterfly curves, time domain waveforms, and spectrum diagrams of silicon steel sheets under different excitations are compared and analyzed. The effects of different operating conditions on the magnetostrictive properties of silicon steel sheets were studied and analyzed, mainly including amplitude and spectrum analysis. Finally, the magnetostrictive peak to peak curves under different operating conditions were extracted, providing a data basis for the core vibration of power equipment.

Particle dynamics in a pseudo-2D spouted bed: Experiments and Euler–Lagrange simulations

This study is dedicated to a comprehensive examination of particle dynamics within a pseudo-2D spouted bed, employing a combination of experimental analysis and numerical simulations conducted with the Euler-Lagrange approach. To develop a robust CFD-DEM model for predicting particle dynamics in a pseudo-2D spouted bed, our proposed methodology includes the measurement of DEM parameters based on experimental data, a grid size independence test assessment, and an analysis of appropriate turbulent models and wall boundary conditions for the fluid phase. The effect of different operating conditions, e.g., particle mass and inlet air velocity, on the complex turbulent multiphase flow behavior is assessed. Additionally, we numerically investigated the frequency of collisions between particles and the temporal changes in collisional forces across various conditions. The experiments and numerical simulations provide valuable insights into the intricacies of particle dynamics within a pseudo-2D spouted bed, offering essential knowledge for the optimization of processes employing this equipment.

Simultaneous absorption of H2S, MM and COS into a novel SRSG absorbent using a rotating packed bed

In industries, many gases are required to remove hydrogen sulfide (H2S) and organic sulfur. However, it is still a huge challenge to achieve the efficient and simultaneous removal using a single process. Herein, a novel simultaneous removal sulfide gas (SRSG) absorbent is developed to simultaneously absorb H2S, methyl mercaptan (MM) and carbonyl sulfide (COS). The absorption mechanism between the SRSG absorbent and H2S, MM, COS is explored by quantum chemistry calculations (QCC) and controlled experiments in a rotating packed bed (RPB). Results indicate that the interaction between SRSG and H2S, MM belongs to physical absorption while COS absorption in SRSG obeys two molecule reaction mechanism. Furthermore, the effect of different operating conditions, including rotating speed (N), liquid flow rate (L), gas–liquid ratio (G/L) and temperature (T), on the absorption efficiencies (η) and gas volumetric mass transfer coefficient (KGa) of H2S, MM and COS is systematically investigated. It can be found that both η and KGa are dependent on those operating conditions. The optimal η value for H2S, MM and COS is up to 99.99%, 100%, 100%, respectively. Moreover, nondimensional equations for Sherwood number (Sh) are established, and the calculated and experimental values of Sh(H2S), Sh(MM) and Sh(COS) are in agreement with a deviation within ±13%, ±13%, and ±20%, respectively. These results will provide a valuable potential technique for simultaneously removing acidic gas components from industrial gases.

Hydrothermal liquefaction of Chlamydomonas nivalis and Nannochloropsis gaditana microalgae under different operating conditions over copper-exchanged zeolites

In this study, two different green microalgae, Chlamydomonas nivalis (C. nivalis) and Nannochloropsis gaditana (N. gaditana), were cultivated in open ponds and the harvested wet biomass was converted to bio-crude by hydrothermal liquefaction (HTL) with/without catalyst. Catalytic HTL experiments were performed by using copper-exchanged zeolites including Cu-MOR, Cu-ZSM-5, and Cu-SSZ13, synthesized by recently developed supercritical ion exchange method using scCO2. The composition of all bio-crudes was analyzed by elemental analysis and GC/MS. First, the effects of different operating conditions on the yields of the products and the bio-crude composition were determined for non-catalytic process. Temperature, duration, and water/algae biomass ratio in the feed were the process parameters investigated in the ranges of 250–350 ºC, 10–60 min, and 5–20 wt%, respectively. For C. nivalis, 300 ºC, 60 min, and water/algae ratio of 4 were the optimum conditions which led to maximum bio-crude yield of 18.8 wt%, while 300 ºC, 30 min, and water/algae ratio of 9 were the optimum ones for N. gaditana at which the maximum bio-crude yield of 34.0 wt% was observed. Bio-crude yield of N. gaditana was improved using Cu-MOR, while using catalysts for the case of C. nivalis resulted in more gasification with no positive effect on bio-crude yield. Moreover, elemental analysis showed that the fraction of nitrogen and oxygen in biocrude decreased in catalytic HTL runs, in line with the GC/MS results showing that the concentration of hydrocarbons and cyclic compounds increased in the presence of catalysts accompanied by a decrease in concentration of nitrogenous compounds.

Enhanced nitrogen removal through aerobic denitrifying bacteria in horizontal subsurface flow constructed wetlands: Influencing factors and microbial community structure

Variation in the demand for dissolved oxygen during nitrification and denitrification processes is one of the main constraints for nitrogen removal performance in conventional constructed wetlands. This study aimed to enhance the performance of horizontal submerged flow constructed wetland (HSCW) systems through aerobic denitrification (AD). The effects of different operating conditions on the performance and microbial community structure of the system were investigated using three experimental systems including a non-aerated HSCW without bacterial inoculation (CWC), a non-aerated HSCW with bacterial inoculation (CWM) and an intermittently aerated HSCW with bacterial inoculation (CWMA). Results showed that C/N ratio of 10 and aeration rate of 0.2 L/(min·L) were the optimum conditions for CWMA, which showed 29.01 % and 12.17 % higher COD and TN removals than CWC, even at an average temperature of 8.80℃. Microbial community analysis revealed that the addition of Pseudomonas stutzeri significantly increased the microbial diversity and abundance within the HSCWs. This study provides a new idea for the treatment of nitrogenous wastewater and the AD-CW system has a promising application in low-temperature areas.

Energy and exergy analysis of drying of potash particles in a pulsation-assisted fluidized bed

Potash particles exhibit cohesiveness and hygroscopic behavior in the presence of moisture. During the drying of wet potash particles, solid bridges form, and the agglomeration behavior of such particles reduces the efficiency of drying. In this work, pulsed airflow was employed to break agglomeration and eliminate channeling in a fluidized bed with wet potash particles. The effect of different operating conditions including inlet drying gas temperature (40 °C, 50 °C, and 60 °C) and pulsation frequency (1.0 Hz and 2.0 Hz) on the energy and exergy efficiency of fluidized bed drying of potash particles was investigated. A drying model based on the thin-layer theory was employed to correlate the experimental data of drying of potash particles. The results showed that the highest energy and exergy efficiency of potash drying, 28.6% and 27.8%, respectively, was achieved when the fluidized drying of potash particles was operated at lower temperatures and close to the natural frequency of the fluidized bed system.

Multi-Metal Oxide Catalyst for Electrochemical Oxidation of Organic Pollutants

In recent years, there has been a growing interest in developing highly efficient and stable catalysts for the electro-oxidation of water. These catalysts, besides water electrolysis, could be also a good alternative for removing organic pollutants from water by electro-degradation. Among the innovative groups of catalysts that have been investigated for this purpose, multi-metal oxides have been extensively studied for water electrolysis, but rarely for the direct or indirect oxidation of organic pollutants from water.1 Multi-metal oxide catalysts are composed of two or more metal cations that are chemically bonded to oxygen ions. The combination of different metal cations in a single oxide structure can lead to synergistic effects, which can enhance the catalytic activity and stability of the material. Several types of multi-metal oxide catalysts have been investigated for the electro-oxidation of water, including perovskite oxides, spinel oxides, layered double hydroxides, and mixed metal oxides. Perovskite oxides are a popular class of multi-metal oxide catalysts, which exhibit a wide range of interesting properties, including high catalytic activity, ionic and electronic conductivity, and thermal stability. These properties make perovskite oxides attractive materials for applications in various fields, such as environmental remediation.2 Additionally, the properties of perovskite oxides can be fine-tuned by doping or modifying their chemical composition, morphology, and crystal structure leading to the development of new materials with tailored properties.In this work, multi-metal oxide (perovskite) nanoparticles were synthesized by the hydrothermal method by adjusting the pressure and temperature to obtain multi-metal oxides with controlled crystallinity and morphology. The synthesis was successfully scaled up and electrodes were prepared by impregnating 3D supports with the active materials. The electrocatalytic activity of the prepared electrodes was analyzed by physical and electrochemical characterizations. Moreover, to evaluate the potential application of multi-metal oxide electrodes for organic pollutants removal, phenol was selected as the target pollutant. To complete the research, the effect of different operational conditions (current density, initial pH, initial phenol concentration, and flow rate) on the COD removal of the wastewater in the divided flow cell configuration was investigated. Furthermore, the removal pathway was studied using GC/MS. Acknowledgment: This project has received funding through the HYSOLCHEM project (grant agreement No. 101017928) from the European Union’s Horizon 2020 research and innovation programme.

Experimental studies on renewable hydrogen production by steam reforming of glycerol over zirconia promoted on Ni/Al2O3 catalyst

Abstract The impact of ZrO2 as a catalytic promoter for nickel-based alumina supported catalysts has been studied for the hydrogen synthesis via glycerol steam reforming. Hydrogen is a promising contender of clean fuel and has a key significance in the quest of an environment-preservation, low emission and more sustainable energy approach. Glycerol is a by-product produced during production of biodiesel by trans-esterification of vegetable oils. The higher hydrogen content in glycerol makes it the potential renewable feedstock for hydrogen production. Steam reforming process is the best method available which is highest in energy efficiency and most importantly most economical. The production of catalysts was based on the wet impregnation and co-precipitation methods. The majority of the bulk and surface properties of different synthesized catalysts were considered and determined by several characterization techniques like X-ray diffraction technique, BET surface area and scanning electron microscopy. The performance of catalyst is based on glycerol conversion and hydrogen yield obtained from the steam reforming process taking place in the fixed bed catalytic reactor. The effect of different operating conditions like contact time, temperature, metal loading, and steam to glycerol ratio were investigated to produce maximum hydrogen and glycerol conversion. The results show that the incorporation of promoter 2 % ZrO2 improved the activity of Ni/Al2O3 catalysts significantly resulting 96 % glycerol conversion, 84 % hydrogen production and greater stability at contact time = 15 kg cat s/mol, temperature = 800 °C, steam to glycerol ratio = 9:1 mol/mol, and pressure = 1 atm.

Electrochemical activation of peroxydisulfate by Ti/IrTaO2 anode for quick degradation of xanthate

High concentrations of residual xanthate in mineral processing wastewater often limit the reuse of tailing water. Targeted removal of xanthate is an effective strategy for improving the tailing water recycling rate. In this study, the degradation efficiency and mechanism of sodium ethyl xanthate (SEX) in an electroactivated peroxydisulfate (EAPDS) system were investigated systematically. To avoid the influence of co-existing organic and inorganic matters in real flotation wastewater, we used simulated SEX wastewater to conduct the efficiency and mechanism investigation. A significant synergistic effect between electrocatalysis and peroxydisulfate was observed during the SEX decomposition. When the initial concentration of SEX was 200 mg/L, it achieved 100% removal rate only in 30 min with PDS dosage of 5 mM at current density of 10 mA/cm2. The introduction of peroxydisulfate boosted the removal efficiency six-fold compared to electrocatalysis alone. UV-Vis spectroscopy and GC-MS analyses revealed that the intermediate products of SEX were C2H5OH and CS2. The reactive oxygen species induced in the EAPDS were identified using a series of detection methods. •OH, 1O2, h+, O2•− and electron transportation process (ETP) all contributed to SEX removal. The degradation mechanism in the EAPDS system was proposed based on the analysis of the reactive oxygen species and products. Application to real flotation wastewater was attempted as well. The effects of different operating conditions were also evaluated, including pH, coexisting anions, PDS dosage, and current density. This study provides a new approach for the rapid removal of residual xanthates from mineral processing wastewater.

Treatment of food processing industries wastewater using a novel Fuller's earth clay-based tubular ceramic membrane.

This study investigates the feasibility of a robust, low-cost tubular microfiltration ceramic membrane fabricated using a mixture of locally available Fuller's earth clay (FEC) and solid waste material, rice husk ash (RHA), to treat effluents generated by a local dairy and palm oil industries. Fabrication of the membrane was carried out by employing the extrusion method followed by sintering at a temperature of 850 °C. Raw materials were characterized using XRD, XRF, FTIR, TGA, and differential thermal analysis (DTA). The membrane that underwent sintering exhibits a 61% porosity level, 43.29 L/m2 h bar water permeability, 0.115 μm average pore size, and relatively good corrosion resistance. Further, the effect of different operating conditions, including pressure (1.03-2.41 bar) and cross-flow rate (30-150 Lph), on the microfiltration of both the wastewaters is studied. The membrane lowered the COD levels below the discharge limit (<200 mg/L) of the Central Pollution Control of India for both wastewaters. Finally, Hermia's fouling models were used to identify the fouling mechanism concerned.

Modeling of contact thermal resistance in lateral capillary tube-suction line heat exchangers with experimental validation and investigation

This paper studied the lateral capillary tube-suction line heat exchanger (CTSLHX) with different contact types and different geometries. An improved one-dimensional model of the CTSLHX was established, using the CFD model to derive the contact thermal resistance between the capillary tube and the suction tube. An experimental bench was built to test the steady-state heat transfer and flow performance. It was found that the model predicted 87.6 % and 98.9 % of the measured mass flow rate within the error band of ± 10 % and ± 15 %. The prediction error of the CTSLHX heat transfer effectiveness was within ± 10 %. Parametric effects of different operating conditions and structural parameters on the performance of CTSLHX were investigated. Furthermore, experiments were carried out to study the temperature distribution along the transition section between the exit of the capillary tube and the evaporator. The unique temperature increase reveals that it is beneficial for reducing noise by wrapping a layer of rubber around the second increaser fitting.