Performance Of Cooling System Research Articles

Preliminary study of the thermoelectric cooler and heat pipe application for the cooling system in cabin pickup car

Abstract Car cooling systems are essential equipment to make passengers comfortable, but their energy consumption is very high. Thermoelectric technology has been widely applied as a cooler in many applications, but its use as a car cooler has not been widely used. This research aims to conduct a preliminary study using thermoelectric coolers (TEC) as alternative coolers in pickup cars and to investigate the effect of thermoelectric module and heat exchanger configurations on cooling systems performance. A-TEC cooling system usually uses conventional heat sinks on the cold side and hot side of the TEC. In this study, heat pipes are used as heat exchangers on the hot side of TEC to improve its performance. The cooling system consists of 2 units installed at the rear of the pickup car cabin. Tests were varied using 2 TEC modules arranged in series and 4 TECs arranged in parallel thermal and electrical series. The results showed that using two cooling system units consisting of four TEC modules equipped with heat pipes was able to cool the temperature of the pickup car cabin at 27.4 °C and obtained the highest COP value of 1.16. It shows heat pipes can enhance TEC cooling system performance, producing lower cabin temperatures than conventional heat sinks.

Simulation of cooling system performance of super magnetostrictive actuator for high-speed trains

Simulation of cooling system performance of super magnetostrictive actuator for high-speed trains

Exergo-enviro-economic analyses of solar energy based novel air cooling system

Implementation of heating, ventilation, and air conditioning units in buildings for space cooling represents a passive method for achieving thermal comfort and reducing power consumption. This paper introduces solar energy assisted in-direct evaporative cooling system with a novel multi-passage dry channel. The main objectives are to evaluate exergy variations, sustainability, and total cooling cost based on the inlet conditions for four modes: A, B, C, D (without evaporative cooling, with evaporative cooling, preheating, and preheating with humidification). This comparative study explores thermal performance enhancement of an indirect evaporative cooling system across four operational modes. Mainly, the exergy outlet values increase significantly by 77.39%, while exergy destruction decreases by 54.86%. Both energetic and exergetic coefficient of performances witness remarkable enhancements, with energetic Coefficient of Performance (COP) rising by 321.32%. Exergy efficiency experiences a notable enhancement of 29.974%, and sustainability index shows a consistent upward trend, with a 119.34% increase observed in Mode D compared from Mode A. Entropy generation decreases significantly, indicating improved system efficiency. Total capital cost per unit of cooling capacity decreases notably, highlighting cost savings. These findings underscore the effectiveness of incorporating preheating and humidification processes in optimizing indirect evaporative cooling system performance, emphasizing both exergy efficiency and cost-effectiveness.

Comparative Study on Heat Dissipation Performance of Pure Immersion and Immersion Jet Liquid Cooling System for Single Server

Heat dissipation has emerged as a critical challenge in server cooling due to the escalating number of servers within data centers. The potential of immersion jet technology to be applied in large-scale data center server operations remains unexplored. This paper introduces an innovative immersion jet liquid cooling system. The primary objective is to investigate the synergistic integration of immersion liquid cooling and jet cooling to enhance the heat dissipation capacity of server liquid cooling systems. By constructing a single-server liquid cooling test bench, this study compares the heat dissipation efficiencies of pure immersion and immersion jet liquid cooling systems and examines the impact of inlet water temperature, jet distance, and inlet water flow rate on system performance. The experimental outcomes show that the steady-state surface heat transfer coefficient of the immersion jet liquid cooling system is 2.6 times that of the pure immersion system, with increases of approximately 475.9 W/(m2·K) and 1745.0 W/(m2·K) upon adjustment of the jet distance and flow rate, respectively. Furthermore, the system model is streamlined through dimensional analysis, yielding a dimensionless relationship that encompasses parameters such as inlet water temperature, jet distance, and inlet water velocity. The correlation error is maintained below 18%, thereby enhancing the comprehension of the immersion jet cooling mechanism.

Impact of Building Envelope Materials on Energy Usage and Performance of Evaporative Cooling System in Residential Building

Impact of Building Envelope Materials on Energy Usage and Performance of Evaporative Cooling System in Residential Building

Experimental Study on the Effect of Varying Operating Conditions on Performance of Compressive Cooling System

Air conditioning and cooling systems could be negatively influenced by the external conditions, and it is quite possible that this harmful effect reduces the performance of these systems. This is because these unites requiring the outside temperatures to be lower than the heat being released from them. Unfortunately, this would not work in a favor of saving energy. To avoid low efficiency and to maintain high performance of the cooling system, those devices should be carefully selected based on experimental studies undergoing different local conditions.This humble article aims to experimentally investigate the effect of changing the external operating conditions on the performance of a compressive cooling system. The test facility was designed and arranged to simulate the external operating conditions. The outside conditions surrounding the condenser (such as speed of air movement, external air temperature) were varied, and accordingly the pressures and temperatures of specific points in the system were measured.This study has found that the speed of air movement and high temperature of air ambient negatively influenced the performance of the cooling system. The optimum value of the performance of the compressive cooling system obtained at the external air temperature range of (18 → 28 C°). Additionally, the research suggested that the relative humidity of the atmosphere should exceed 50% for this case of study. Therefore, selecting a suitable place for the compressive cooling system is crucial to attain a better performance with less consumption of electricity.

Experimental studies on the impact of adsorbent particle size on the adsorption chiller performance

Adsorption chiller dynamics and its effect on the performance are greatly influenced by the adsorbent particle size because they govern both the micro (intra-particle) and macro (inter-particle) heat and mass transfer resistances within the adsorber bed. The net effect of adsorbent particle size and shape on the overall cooling system performance is addressed here. Initial CFD analysis of columnar adsorber bed with silica gel + water as the working pair, assuming uniform spherical adsorbent, showed increased uptake capacity with smaller sized (0.23 mm radius) particles over bigger sized (0.8 mm radius) ones despite smaller vapor penetration depth of the former. Subsequently, the effect of adsorbent particle size and shape on the overall cooling system performance is investigated experimentally in a single-stage one-bed mode for RD 2060 (0.8 mm radius) and RD 3070 (0.23 mm radius) silica gel specimens. Though the smaller size of RD 3070 is favourable for the adsorption kinetics at the particle level, its non-spherical shape and highly non-uniform size distribution resulted in significantly lower permeability and thermal diffusivity of the packed adsorber bed, thus hindering the cyclic steady state throughput. For the same operating conditions, RD 2060 and RD 3070 yield a cooling capacity (CC) of 107 W and 22 W, respectively. Further, the coefficient of performance (COP) drops by 73% in the case of RD 3070. The present study indicates that the adsorber bed design must consider both the adsorbent size and shape, in addition to other system operational parameters to enhance performance indicators.

A Numerical Investigation of the Influence of Humid Environments on the Thermal Performance of a Phase Change Thermal Storage Cooling System in Buildings

Phase change thermal energy storage (PCTES) technology has garnered significant attention in addressing thermal management challenges in building HVAC systems. However, the cooling performance of PCTES systems in humid scenarios remains unexplored, which is crucial in subtropical regions, high-humidity underground areas, and densely populated spaces. Taking the mine refuge chamber (MRC) as an example, this study focuses on a passive temperature and humidity control system by employing cold storage phase change plates (PCPs) for 96 h. First, an improved and simplified full-scale numerical model including PCPs and MRC parts is established. Then, the model is validated through the experimental results and solved using a numerical method. Finally, the influence of various factors within the system is investigated and an optimization method involving batch operation is proposed. The results indicate that (1) within 40 h, the use of cold storage PCPs leads to an indoor temperature reduction of 4.8 °C and a 7% decrease in relative humidity; (2) the PCPs show asynchronous states in sensible and latent heat transfer rates; (3) for every 50 additional PCPs, the average indoor temperature increases by 0.6 °C and the relative humidity decreases by 1.5%; (4) implementing batch operation of PCPs ensures that the indoor Heat Index drops by 10 °C, which is vital for human survival. The findings will play a crucial role in the global expansion and application (including geographical and functional aspects) of phase change thermal storage technology.

Natural draft direct dry cooling system performance at various application scales under windless and windy conditions

The natural draft direct dry cooling system (NDDDCS) presents a promising alternative to conventional forced draft air-cooled condensers (ACCs) and indirect natural draft dry cooling systems, overcoming their limitations by efficiently condensing process steam directly and passively. The NDDDCS achieves superior thermal efficiencies while reducing system complexities, operational costs, and auxiliary power consumption. Potential reductions in operational expenses for the system may offset initial capital investments, resulting in lower lifetime costs. While research to date has focused on large-scale NDDDCS performance under varying wind conditions, this work addresses a critical gap by investigating the system’s scalability for various applications, including a large-scale coal-fired power plant (900 MWt, 165 m total height), a medium-scale concentrated solar power plant (CSP) (100 MWt, 65 m total height), and a small-scale water desalination plant (1 MWt, 11.5 m total height) under both windless and windy conditions. To achieve this, a steady-state 3-D computational fluid dynamics (CFD) model is developed, validated and scaled, incorporating innovative features such as an atmospheric pressure gradient and the ability to capture reversed flows through the system’s heat exchangers. Additionally, the model assesses inlet air temperature data at a per-cell resolution, enabling the ability to predict non-uniform temperature distributions in the heat exchangers, including hot-spots caused by airflow recirculation. Analysis of velocity and temperature fields across all scales reveals that recirculation effects negatively impact NDDDCS performance, particularly at the middle circumferential heat exchanger sector. The hyperbolic shape of the tower shell induces internal recirculation zones and reduces the effective flow volume. Under windy conditions, performance losses of 44%, 40%, and 40% are observed at crosswind speeds of 3 m/s, 6 m/s, and 9 m/s for small, medium, and large-scale towers, respectively. Beyond these speeds, the relationship between system performance and draft driving potential becomes non-linear due to crosswind effects dominating. Furthermore, a novel effect is identified at wind speeds of 9 m/s, 15 m/s, and 18 m/s for small, medium, and large-scale systems, respectively, where an inflection point allows for system performance recovery. This study underscores the NDDDCS’s potential as a cooling solution for modern power cycles across various scales, while highlighting the implications of scaling the system for medium- and small-scale thermal applications.

Optimizing Data Centre Energy Efficiency with Dynamic Resource Allocation and Intelligent Cooling Management through Machine Learning

Our research aims to improve energy efficiency in data centres by combining cloud computing infrastructure with machine learning techniques. We propose that dynamic resource assignment, combined with intelligent optimisation of cooling systems, can reduce power waste and operational costs. Real-time sensor data from various data centre components such as servers, cooling systems, and power distribution units is collected and fed into machine learning models for analysis. In this way, we can create power arrangements that are tailored to the resources and needs of various applications. The experimental results show that energy consumption has been reduced by an average of 30% compared to traditional methods. Furthermore, our machine learning models are quite accurate in predicting cooling system performance. For example, an Artificial Neural Network (ANN) has an accuracy rate of 98.78%. This result demonstrates the efficacy of our approach in promoting energy efficiency and operational performance in data centres: it not only provides a scalable, cost-effective solution to industry energy efficiency challenges, but it also improves day-to-day data centre operations by reducing electrical consumption. Our approach, which is based on dynamic allocation of computational resources and real-time data analysis for optimising cooling systems, not only saves energy but also improves operational efficiency. With energy in mind, we must all work towards a more sustainable and green approach to data centre management. Future research can look into other potential optimisations, as well as issues with scalability and application in real-world data centre environments.

Investigation of a Wheel Liquid Desiccant Cooling System Performance via ANSYS CFX

A liquid desiccant cooling system is an alternative air-conditioning system with significant energy-saving potential. This system is commonly used in the industrial sector, such as in dehumidifiers. The key component of the liquid desiccant cooling system is its dehumidification performance. Therefore, a study on a liquid desiccant dehumidifier has been conducted to predict its performance using computational fluid dynamics analysis. In these simulations, the effects of the temperature of the liquid desiccant and the velocity of air flow on the absorption process between the liquid desiccant and air were studied. The same applies to the velocity profile, which helps determine the airflow pattern within the dehumidifier. The model was constructed using ANSYS FLUENT and Autodesk Inventor. The model is the rotary desiccant wheel dehumidifier which was used to dehumidified the air.. ANSYS CFX was used for simulating the velocity profile to achieve the airflow pattern in the dehumidifier. The volume of fluid was selected as the multiphase method for the second simulation process. The temperature and mass fraction of water were monitored within the air during the counterflow simulation between the liquid desiccant and the air. The liquid desiccant chosen for this study was LiCl. The simulations were conducted at specific air velocities, and the behavior within the dehumidifier was observed. The analysis results revealed that the air entering the rotary desiccant wheel dehumidifier experienced a drop in velocity after passing through the desiccant wheel in the middle. Additionally, turbulence occurred after the air passed through the wheel and the dehumidifier’s wall. Based on these findings, the design of an optimal dehumidifier and the selection of an appropriate air velocity for cooling can be carried out.

Study of the influence of raw water infrastructure performance on drinking water

Water utilities are assessed on financial, customer service, operational, and HR performance, according to Government Regulation 122/2015. Environmental, operational, and physical factors impact cooling system performance. Local governments and water utilities assess water supply efficiency using distribution networks. In West Nusa Tenggara, researchers explored Lombok and Sumbawa. Water is abundant in Lombok but insufficient in Sumbawa. Despite the continual requirement for drinking water, this study concentrates on these two criteria since regional climates fluctuate. The former has superior local government water supplies, which affect Lombok and Sumbawa citizens’ health. This research outlines a single drinking water system’s two most important performance criteria. Researchers employ fuzzy c-means clustering, statistical regressive analysis, and questionnaire combinations for indeterminate parameters. The survey concluded that a water distribution authority has a good performance value if its intake and distribution network works effectively and the negative balance decreases. PDAM control will be less effective and the body less healthy if one portion fails, especially if fluctuations of water discharge. This research may result from an integrated drinking water collection and distribution performance model. The study found that water treatment plant performance, especially water discharge, increases water usage.

Project management strategies for implementing energy-efficient cooling solutions in emerging data center markets

Project management strategies play a pivotal role in implementing energy-efficient cooling solutions in emerging data center markets. This review explores key strategies for successful implementation, focusing on the unique challenges and opportunities in these markets. Emerging data center markets are characterized by rapid growth and evolving infrastructure needs. As such, implementing energy-efficient cooling solutions requires a strategic approach that addresses local regulatory requirements, environmental conditions, and technological capabilities. Effective project management in these contexts involves several key strategies. Firstly, thorough planning is essential. This includes conducting feasibility studies, assessing site-specific requirements, and developing detailed project plans. Understanding the local context is crucial, as it can impact the selection and implementation of cooling solutions. Secondly, stakeholder engagement is critical. Engaging with local authorities, communities, and industry stakeholders can help ensure regulatory compliance and garner support for the project. Additionally, involving local experts and partners can provide valuable insights and enhance the project's success. Thirdly, implementing robust monitoring and evaluation mechanisms is essential. Monitoring energy consumption, cooling system performance, and environmental impacts allows for timely adjustments and optimizations, ensuring the long-term sustainability of the cooling solutions. Lastly, knowledge sharing and capacity building are key components of successful project management in emerging data center markets. Providing training and education on energy-efficient practices and technologies can help build local capacity and ensure the continued success of the cooling solutions. In conclusion, project management strategies for implementing energy-efficient cooling solutions in emerging data center markets require a holistic approach that considers local context, engages stakeholders, implements robust monitoring mechanisms, and promotes knowledge sharing. By adopting these strategies, data center operators can effectively address the challenges and opportunities in these markets, contributing to a more sustainable and resilient data center infrastructure.

Heat Transfer Performance of Copper Foam-Based Vapor Chamber Composite Liquid Cooling System Under Double-Sided Heating

Heat Transfer Performance of Copper Foam-Based Vapor Chamber Composite Liquid Cooling System Under Double-Sided Heating

The integrated multi-performance fast optimization strategy for battery thermal management system

Increased battery energy density is required to boost electric vehicle endurance; however, this also raises the possibility of thermal runaway and power battery explosion. Improving the cooling system performance requires optimization and enhancement of classical systems. Traditional design approaches struggle to simultaneously enhance multiple aspects of performance, while an optimization based on Computational Fluid Dynamics (CFD) methods is often inefficient. Therefore, by integrating a flow resistance network model (FRNM) with a weighted average optimization algorithm (INFO), an efficient optimization for the comprehensive performance of the system can be achieved. Five optimized systems under different airflow rates were obtained through optimization. A comparison with two existing systems validated the effectiveness of the optimized system. The results demonstrate that, compared to the two reference systems, the optimized system decreases the maximum temperature difference by 65.51 % and 39.07 %, respectively. Furthermore, the improvement in temperature uniformity is more significant, increasing by 63.76 % and 34.40 %, respectively.

Thermodynamic analysis for new solutions of data center cooling with adsorption refrigeration and heat pipe

This study investigated the potential of integrating separate heat pipe and adsorption refrigeration systems as a data center efficient cooling system. Compared to water-cooled data centers, this approach demonstrates improved heat transfer efficiency and reduced energy consumption. The effectiveness of heat transfer in this approach is illustrated by applying exergy and entranspy theories. By conducting numerical simulations across five representative Chinese cities with different climates, both Power Usage Effectiveness (PUE) and key cooling system performance indicators are assessed. The analysis reveals that all cities can achieve a PUE below 1.095, realized a 65.87 % and 13.60 % reduction in cooling system energy consumption and entransy dissipation, respectively. Data centers using mechanical chiller cooling cause a high energy consumption. This paper indicates the benefits of integrating heat pipe and adsorption refrigeration systems in reducing energy consumption and optimizing overall data center performance.

Numerical Investigations of the Cooling Performance of an R410A Closed-Loop Spray Cooling System

To investigate the spray cooling characteristics and the impact of spray parameters such as chamber pressure, spray height, and spray tilt angle on heat transfer efficiency, a mathematical model based on the Eulerian–Lagrangian frame was established for an R410A closed-loop spray cooling system. The results revealed that the spray pattern is conical, with the center velocity significantly higher than the edge velocity. The temperature distribution of the cooling surface and liquid film height both exhibit a “W” shape, and the surface temperature is lower where the liquid film is thin. There is an optimal liquid film height of approximately 5 μm, at which the cooling surface temperature is the lowest. The surface temperature increases with an increase in the spray chamber pressure. Considering average cooling surface temperature, the optimal tilt angle is 40° with an average surface temperature of 330.1 K. When considering wall temperature and wall heat transfer coefficient uniformity, however, the optimal tilt angle is 10°, leading to the average surface temperature of 332.6 K. When increasing the optimal spray height to 70 mm, the average surface temperature is 313.4 K.

EXPERIMENTAL AND NUMERICAL STUDY ON EFFECTS OF NEW-GENERATION FINNED HEAT EXCHANGER ON THERMAL PERFORMANCE OF THERMOELECTRIC COOLING SYSTEMS

In this study, an attempt has been made to increase the efficiency of the thermoelectric refrigerator by designinig a new-generation finned heat exchanger. Surface extension, which is one of the most applied passive heat transfer enhancement techniques, was applied for this finned heat exchanger. In this application, the heat absorbed from the cooling room is transferred to the external environment more effectively. In addition, by using an external thermoelectric element (which is installed with the secondary heat exchanger), the heat exchanger cools down faster and the heat is transferred to the environment more quickly. The manufactured cooling system was tested experimentally under different working conditions, including natural and forced convection. The effects of air velocity and applied voltage to the external TE module on thermal performance were examined. Additionally, the external finned heat exchanger has been simulated and heat transfer characteristics have been evaluated using computational fluid dynamics. The lowest and highest COP values have been obtained as 0.003 and 0.011, respectively, when the external TE module has been passive. By providing 12 V for the external TE module, the lowest and highest COP values have been observed as 0.0031 and 0.0042, respectively. In addition, the importance of surface extension applications for the efficient operation of thermoelectric elements has been emphasized.

THE SIGNIFICANCE OF PROPER COOLING TOWER WATER TREATMENT: A CASE STUDY

This paper presents the result of a study of the effect of cooling tower system in terms of performance and cost of maintenance. The study was conducted in a two-storey shopping complex building. Observation on site was held to obtain data on full load amp (FLA) and chilled water temperature (CWT) before and after servicing cooling tower unit. Energy of cooling tower were evaluated by analysis of FLA and CWT in percentage value. The condition on the system and component were also observed to differentiate the condition before and after treatment. The result obtained showed that cooling system performance after the treatment was increased.

Numerical analysis of flow and heat transfer characteristics of supercritical endothermic hydrocarbon fuel in taper tube

To enhance the cooling performance of the scramjet regenerative cooling system, a novel taper tube is proposed. Under supercritical pressure, the flow characteristics and heat transfer characteristics of endothermic hydrocarbon fuel (EHF) in taper tube, narrow cylindrical tube, and wide cylindrical tube are numerical investigated and compared. The results of the investigation of flow and heat transfer processes in the above three tubes indicate that the taper tube effectively facilitates the pyrolysis of n-decane and the n-decane conversion is increased by 3.94%, compared with narrow cylindrical tube. Compared with wide cylindrical tube, the taper tube enhances cooling effect and the wall temperature near the outlet is reduced by 50.16 K. The taper tube contributes to the cooling structure optimization and promotion of regenerative cooling system performance.