scholarly journals Physicochemical characteristics of solid particles of contaminants in the coolant of automobile and tractor engines

2021 ◽  
Vol 1 (3) ◽  
pp. 53-61
Author(s):  
S.G. Dragomirov ◽  
◽  
P.Ig. Eydel ◽  
A.Yu. Gamayunov ◽  
M.S. Dragomirov ◽  
...  
Keyword(s):  
High Performance ◽  
Cooling System ◽  
Chemical Elements ◽  
Dissimilar Materials ◽  
Physicochemical Characteristics ◽  
Operating Conditions ◽  
Solid Particles ◽  
Physicochemical Interaction ◽  
Cooling Systems ◽  
Thin Oxide Film

The article describes the results of a study of the physicochemical characteristics of solid particles of contaminants present in the coolant of automobile and tractor engines. The data on the fractional, physical and chemical composition of solid particles of contamination are given. It was established that the generalized reason for the appearance of contaminants of various nature in liquid cooling systems of engines is the physicochemical interaction of the coolant (antifreeze) with different elements and dissimilar materials of the cooling system. The use of absolutely pure coolant in the cooling systems of automobile and tractor engines is practically unrealistic, since there will always be operating conditions that contribute to the formation of contamination. A number of chemical elements (in an amount from 1 to 47% of each element) were found in the composition of solid particles of coolant contaminants: iron Fe, silicon Si, aluminum Al, lead Pb, tin Sn, zinc Zn, calcium Ca, magnesium Mg, copper Cu. In addition, at a level of less than 1.0% (wt.), Such chemical elements as potassium K, sodium Na, titanium Ti, phosphorus P, sulfur S, chromium Cr, molyb-denum Mo, chlorine Cl, iridium Ir, nickel Ni, manganese Mn, etc. were found. The most dangerous contaminants are particles of iron Fe and silicon Si, contained in the coolant in an amount of up to 47 and 37%, respectively, and possessing significant hardness and angularity. The abrasive proper-ties of Fe and Si particles create the danger of removing a thin oxide film on the inner surface of the walls of the cooling radiator channels, leading to their premature destruction. In this regard, it is concluded that high-performance engine coolant filters should be used in automobiles and tractors to remove these contaminants from the flow.

Remote Heat Pipe Based Heat Exchanger Performance in Notebook Cooling

2005 ◽  
Author(s):  
Seyyed Khandani ◽  
Himanshu Pokharna ◽  
Sridhar Machiroutu ◽  
Eric DiStefano
Keyword(s):  
Heat Exchanger ◽  
Thermal Resistance ◽  
Heat Pipe ◽  
Cooling System ◽  
Temperature Drop ◽  
Operating Conditions ◽  
Cooling Systems ◽  
Temperature Variations ◽  
Non Linear ◽  
Condenser Temperature

Remote heat pipe based heat exchanger cooling systems are becoming increasingly popular in cooling of notebook computers. In such cooling systems, one or more heat pipes transfer the heat from the more populated area to a location with sufficient space allowing the use of a heat exchanger for removal of the heat from the system. In analsysis of such systems, the temperature drop in the condenser section of the heat pipe is assumed negligible due to the nature of the condensation process. However, in testing of various systems, non linear longitudinal temperature drops in the heat pipe in the range of 2 to 15 °C, for different processor power and heat exchanger airflow, have been measured. Such temperature drops could cause higher condenser thermal resistance and result in lower overall heat exchanger performance. In fact the application of the conventional method of estimating the thermal performance, which does not consider such a nonlinear temperature variations, results in inaccurate design of the cooling system and requires unnecessarily higher safety factors to compensate for this inaccuracy. To address the problem, this paper offers a new analytical approach for modeling the heat pipe based heat exchanger performance under various operating conditions. The method can be used with any arbitrary condenser temperature variations. The results of the model show significant increase in heat exchanger thermal resistance when considering a non linear condenser temperature drop. The experimental data also verifies the result of the model with sufficient accuracy and therefore validates the application of this model in estimating the performance of these systems.   This paper was also originally published as part of the Proceedings of the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems.

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.

A High Performance Semi-Passive Cooling System: The Pulse Thermal Loop

Volume 3 ◽  
2004 ◽  
Author(s):  
Mark M. Weislogel ◽  
Michael A. Bacich
Keyword(s):  
Heat Transport ◽  
High Performance ◽  
Driving Forces ◽  
Cooling System ◽  
Heat Pipes ◽  
Thermal Control ◽  
High Heat ◽  
Transport Systems ◽  
Passive Cooling ◽  
Cooling Systems

Over the past decade, the search for and development of high performance thermal transport systems for a variety of cooling and thermal control applications have intensified. One approach employs a new semi-passive oscillatory heat transport system called the Pulse Thermal Loop (PTL). The PTL, which has only recently begun to be characterized, exploits large pressure differentials from coupled evaporators to force (pulse) fluid through the system. Driving pressures of over 1.8MPa (260psid) have been demonstrated. Other passive cooling systems, such as heat pipes and Loop Heat Pipes, are limited by capillary driving forces, typically less than 70kPa (10psid). Large driving forces can be achieved by a mechanically pumped loop, however, at the expense of increased power consumption, increased total mass, and increased system cost and complexity. The PTL can be configured in either active or semi-passive modes, it can be readily designed for large ∼ O(100kW) or small ∼ O(10W) heat loads, and it has a variety of unique performance characteristics. For low surface tension dielectric fluids such as R-134a, the PTL system has over a 10-fold heat carrying capacity in comparison to high performance heat pipes. Data accumulated thus far demonstrate that the PTL can meet many of the requirements of advanced terrestrial and spacecraft cooling systems: a system that is robust, ‘semi-passive,’ high flux, and offers high heat transport thermal control while remaining flexible in design, potentially lightweight, and cost competitive.

scholarly journals Surrogate-Based Optimization of a Centrifugal Pump with Volute Casing for an Automotive Engine Cooling System

2021 ◽  
Vol 11 (23) ◽  
pp. 11470
Author(s):  
Remo De Donno ◽  
Alessia Fracassi ◽  
Antonio Ghidoni ◽  
Alessandro Morelli ◽  
Gianmaria Noventa
Keyword(s):  
Centrifugal Pump ◽  
High Performance ◽  
Cooling System ◽  
Optimization Technique ◽  
Volumetric Flow Rate ◽  
Optimization Procedure ◽  
Operating Conditions ◽  
Centrifugal Pumps ◽  
Automotive Engine ◽  
Surrogate Based Optimization

This paper investigates the capability of a surrogate-based optimization technique for the advanced design of centrifugal pumps. The centrifugal pump considered in this work is designed for the automotive cooling system and consists of an impeller, a vaneless diffuser and a volute. A fully three-dimensional geometry parametrization based on Bézier surfaces is presented. The optimization procedure includes the following software packages: Scilab for the geometric parametrization, Ansys-CFX for the CFD simulations and DAKOTA for the optimization management. The initial geometry is defined by a 0D code that provides a preliminary design of the pump, given the operating conditions, i.e., the volumetric flow rate, the head and the rotating speed. In this work an operative point typical of high performance gasoline cars is considered.

Development of Advanced Cooling Network Systems for Data Centers

2010 ◽  
Author(s):  
Yoshiyuki Abe ◽  
Mayumi Ouchi ◽  
Masato Fukagaya ◽  
Takashi Kitagawa ◽  
Haruhiko Ohta ◽  
...  
Keyword(s):  
High Performance ◽  
Data Centers ◽  
Cooling System ◽  
Heat Pipes ◽  
Energy Utilization ◽  
Liquid Cooling ◽  
Network Systems ◽  
Two Phase ◽  
Cooling Systems ◽  
Development Organization

Energy utilization in data centers, especially cooling systems for server racks, needs extensive improvement. The present authors proposed advanced cooling network systems for data centers, and R & D activities have been conducted under the so-called Green IT Project sponsored by NEDO (New Energy and Industrial Technology Development Organization). In the present concept, CPUs in servers are cooled down by either direct liquid cooling system or heat pipes with liquid cooling systems in the condensation region. The liquid cooling systems are integrated in each server rack and among server racks. A series of studies on both single phase and two phase narrow channel heat exchangers, high performance heat pipes with self-rewetting fluids and nanofluids for heat transfer enhancement are ongoing. In addition, a prototype server rack with the cooling network systems is also under development toward commercial products. This paper reports the updated status of the present R & D.

scholarly journals Comparing Performance Metrics of Partial Aisle Containments in Hard Floor and Raised Floor Data Centers Using CFD

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1473 ◽  
Author(s):  
Emelie Wibron ◽  
Anna-Lena Ljung ◽  
T. Staffan Lundström
Keyword(s):  
Flow Rate ◽  
Data Centers ◽  
Performance Metrics ◽  
Cooling System ◽  
Operating Conditions ◽  
Cooling Systems ◽  
Hot Air ◽  
Ansys Cfx ◽  
Computational Fluid Dynamics Cfd ◽  
Hard Floor

In data centers, efficient cooling systems are required to both keep the energy consumption as low as possible and to fulfill the temperature requirements. The aim of this work is to numerically investigate the effects of using partial aisle containment between the server racks for hard and raised floor configurations. The computational fluid dynamics (CFD) software ANSYS CFX was used together with the Reynolds stress turbulence model to perform the simulations. Velocity measurements in a server room were used for validation. Boundary conditions and the load of each rack were also retrieved from the experimental facility, implying an uneven load between the racks. A combination of the performance metrics Rack Cooling Index (RCI), Return Temperature Index (RTI) and Capture Index (CI) were used to evaluate the performance of the cooling systems for two supply flow rates at a 100% and 50% of operating condition. Based on the combination of performance metrics, the airflow management was improved in the raised floor configurations. With the supply flow rate set to operating conditions, the RCI was 100% for both raised floor and hard floor setups. The top- or side-cover fully prevented recirculation for the raised floor configuration, while it reduced the recirculation for the hard floor configuration. However, the RTI was low, close to 40% in the hard floor case, indicating poor energy efficiency. With the supply flow rate decreasing with 50%, the RTI increased to above 80%. Recirculation of hot air was indicated for all the containments when the supply rate was 50%, but the values of RCI still indicated an acceptable performance of the cooling system.

scholarly journals Adsorbents, Working Pairs and Coated Beds for Natural Refrigerants in Adsorption Chillers—State of the Art

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4707
Author(s):  
Piotr Boruta ◽  
Tomasz Bujok ◽  
Łukasz Mika ◽  
Karol Sztekler
Keyword(s):  
Cooling System ◽  
Fundamental Problem ◽  
Thermodynamic Cycle ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Adsorption Refrigeration ◽  
Cooling Systems ◽  
Sustainable Solutions ◽  
Improved Performance

Adsorption refrigeration systems are promising, sustainable solutions for many cooling applications. The operating range and the performance of an adsorption cooling cycle are strongly dependent on the properties of adsorbents, adsorbates, and bed coatings. Therefore, further research and analysis may lead to improved performance of adsorption coolers. In this paper, studies on working pairs using natural refrigerants and the properties of adsorbent coatings were reviewed. The selected working pairs were then thermodynamically characterised and ranked in terms of refrigerant evaporation temperature values. This was found to be a key parameter affecting the applicability of a given adsorbent/adsorbate pair and the value of SCP (Specific Cooling Power), COP (Coefficient of Performance) parameters, which are now commonly used comparison criteria of adsorption chillers. In the analysis of the coating studies, the focus was on the effect of individual parameters on the performance of the cooling system and the effect of using coated beds compared to packed beds. It was found that a fundamental problem in comparing the performance of different cooling systems is the use of different operating conditions during the tests. Therefore, the analysis compares the performance of the systems along with the most important thermodynamic cycle parameters for the latest studies.

scholarly journals Turbine Blade Cooling System Optimization

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Julian Girardeau ◽  
Jérôme Pailhes ◽  
Patrick Sebastian ◽  
Frédéric Pardo ◽  
Jean-Pierre Nadeau
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
Cooling System ◽  
System Optimization ◽  
Internal Cooling ◽  
Cooling Systems ◽  
Turbine Blade Cooling ◽  
Turbine Vanes ◽  
Low Efficiency ◽  
Aerodynamic Losses

Designing high performance cooling systems suitable for preserving the service lifetime of nozzle guide vanes of turboshaft engines leads to significant aerodynamic losses. These losses jeopardize the performance of the whole engine. In the same time, a low efficiency cooling system may affect the costs of maintenance repair and overhaul of the engine as component life decreases. Consequently, designing cooling systems of gas turbine vanes is related to a multiobjective design problem. In this paper, it is addressed by investigating the functioning of a blade and optimizing its design by means of an evolutionary algorithm. Systematic 3D CFD simulations are performed to solve the aero-thermal problem. Then, the initial multiobjective problem is solved by aggregating the multiple design objectives into one single relevant and balanced mono-objective function; two different types of mono-objective functions are proposed and compared. This paper also proposes to enhance available knowledge in the literature of cooling systems of gas turbine vanes by simulating the internal cooling system of the vane. From simulations thermal efficiency and aerodynamic losses are compared and their respective influences on the global performances of the whole engine are investigated. Finally, several optimal designs are proposed.

scholarly journals Investigation of the Environmentally-Friendly Refrigerant R152a for Air Conditioning Purposes

2018 ◽  
Vol 9 (1) ◽  
pp. 119 ◽  
Author(s):  
Evangelos Bellos ◽  
Christos Tzivanidis
Keyword(s):  
Heat Pump ◽  
High Performance ◽  
Environmentally Friendly ◽  
Cooling Capacity ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Cooling Systems ◽  
Detailed Model ◽  
Ambient Temperatures

Heat pumps are efficient and well-established technologies for providing the proper cooling load in the building sector. The objective of this work is the parametric investigation of a heat pump operating with the promising refrigerant R152a for different operating conditions. More specifically, the heat pump is studied for different ambient temperatures, different indoor temperatures and various compressor rotational speeds. The cooling capacity and the coefficient of performance (COP) are the most important parameters which calculated in every scenario. A detailed model is developed in Engineering Equations Solver (EES) and it is validated with literature data. According to the final results, the system can operate in nominal conditions with 5 kW cooling capacity and a COP equal to 6.46. It is found that the COP can be ranged from 4 to 12 and the cooling capacity, while the cooling capacity can reach up to 9 kW. Moreover, a regression equation about the performance of the system is suggested. The obtained results indicate that the use of the R152a leads to high performance and so it can be an environmentally friendly choice for the cooling systems.

Loss reduction of outer-rotor type high-speed interior permanent magnet motors

2020 ◽  
Vol 64 (1-4) ◽  
pp. 861-868
Author(s):  
Sho Sakurai ◽  
Kenji Nakamura
Keyword(s):  
Eddy Current ◽  
High Speed ◽  
High Performance ◽  
Cooling System ◽  
Permanent Magnet Motors ◽  
Cooling Systems ◽  
Cooling Fan ◽  
Outer Rotor ◽  
Interior Permanent Magnet ◽  
Rotor Structure

Many communication servers are being installed in order to develop information technology (IT). The servers require not only high-performance processer but also its cooling system. Among the cooling systems, a cooling fan is the most suitable due to good balance between performance and cost. In order to further improve the fan’s performance, both torque and speed of cooling fan motors are increased. However, iron loss and eddy current loss are also increased along with larger torque and higher speed, which worsens the efficiency. This paper investigates the optimum rotor structure for the fan motor in order to obtain sinusoidal flux distribution in air gap, which can reduce the iron and eddy current losses.

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