scholarly journals Simulative Study of Different Control Concepts of Cooling System for Machine Tools

2018 ◽  
Vol 220 ◽  
pp. 08002
Author(s):  
Linart Shabi ◽  
Juliane Weber ◽  
Jürgen Weber

Power losses in machine tools, e.g. during the standby, idle-, and manufacturing process, are converted into heat energy. This causes the machine frame and other machine components to heat up. As a result, the Tool Centre Point (TCP) of the machine tools is moved. The accuracy of the machine is thus reduced during manufacturing. The current cooling system design of machine tools is based on a centrally fixed pump supply that provides a constant cooling volume flow for cooling all the machine tool components. This does not correspond to the individual temperature development of the components, after all, the high temperature fluctuation arises and causes the thermo-elastic deformation of machine tools. The main objective of this paper is to highlight the deficit of the current concept of cooling systems and to present a simulative study on the different controls concepts of cooling systems for machine tools. The results depict that the new concepts under consideration have a large potential for better thermal behaviour and lower hydraulic performance compared to the current cooling system design. The simulation results show a stability of the components’ temperature profile as well as a decreased energy consumption of the cooling system.

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4676
Author(s):  
June-Seok Lee ◽  
Ui-Min Choi

In this paper, the effect of the heat-pipe cooling system design processes on the reliability of the power module in a railway propulsion inverter was investigated. The existing design processes for the heat-pipe cooling system guarantee that the junction temperature of power devices does not exceed the maximum allowable junction temperature when the railway propulsion inverter operates under its mission profile; therefore, each step of the design process was reviewed to analyze the effect of the heat-pipe cooling system. Based on the processes, in the calculation for the required thermal resistance of the heat-pipe cooling system, two difference losses were considered with the thermal resistances of the insulated gate bipolar mode transistor (IGBT) module and the thermal grease at an interface between the baseplate of IGBT module and heat-pipe cooling system. The control scheme and mission profile of the train were taken into account to calculate the power losses. Then, the designed heat-pipe cooling systems were compared in terms of the size and weight. In addition, the junction temperatures and lifetimes of the power module with heat-pipe cooling systems designed by different power losses were estimated and compared. Finally, guidelines for a heat-pipe system cooling design are proposed.


2017 ◽  
Vol 107 (05) ◽  
pp. 359-365
Author(s):  
E. Prof. Uhlmann ◽  
S. Salein

Das wachsende Bewusstsein für eine umweltgerechte und damit nachhaltige Fertigung sowie steigende Energiepreise führen zur erhöhten Nachfrage nach energieeffizienten Lösungsansätzen für langlebige Produktionsmittel. Die Energierückgewinnung von thermischen Verlusten durch thermoelektrische Generatoren stellt hierfür einen innovativen Ansatz dar. Das als Energy Harvesting bekannte Konzept wird am Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF) der Technischen Universität Berlin auf seine Eignung zur Erhöhung der Energieeffizienz von hochdynamischen Werkzeugmaschinen untersucht. Der Fachbeitrag präsentiert experimentelle Ergebnisse zur Rückgewinnung von thermischen Verlusten eines Linearmotors. Die im Wärmefluss platzierten thermoelektrischen Generatoren generieren eine elektrische Leistung, die direkt zur Versorgung des Motorkühlsystems genutzt wird. Die Ergebnisse zeigen, dass die elektrischen Verbraucher eines Wasser- und Luftkühlsystems aus der rückgewonnenen Energie der thermoelektrischen Module betrieben werden können.   The growing awareness for environmentally friendly and sustainable production as well as the increase of energy costs leads to a rising demand for energy efficient solutions for long-life production facilities. An innovative approach in this field is the recuperation of energy from thermal loss through thermoelectric generators. The proof of applicability to use an energy harvesting concept in order to increase the energy efficiency of highly dynamic machine tools with linear direct drives is part of a research objective at the Institute for Machine Tools and Factory Management (IWF) of the Technische Universität Berlin. The present paper investigates experimentally the recuperation of thermal losses in linear direct drives. Thermoelectric generators are placed in the heat flow to convert heat into electric energy which is directly supplied to the cooling system of a device. Experimental results show the feasibility to operate the electrical loads of water and air cooling systems by the electrical energy harvested from thermoelectric generators.


Author(s):  
Felix Welsch ◽  
Susanne-Marie Kirsch ◽  
Nicolas Michaelis ◽  
Paul Motzki ◽  
Marvin Schmidt ◽  
...  

Elastocaloric cooling is a novel environment-friendly alternative to vapor compression-based cooling systems. This solid-state cooling technology uses NiTi shape memory alloys (SMAs) as cooling medium. SMAs are well known for lightweight actuator systems and biomedical applications, but in addition, these alloys exhibit excellent cooling properties. Due to the high latent heats activated by mechanical loading/unloading, large temperature changes can be generated in the material. Accompanied by a small required work input, this also leads to a high coefficient of performance superior to vapor compression-based systems. In order to access the potential of these alloys, the development of suitable thermodynamic cooling cycles and an efficient system design are required. This paper presents a model-based design process of an elastocaloric air-cooling device. The device is divided into two parts, a mechanical system for continuously loading and unloading of multiple SMA wire bundles by a rotary motor and a heat transfer system. The heat transfer system enables an efficient heat exchange between the heat source and the SMA wires as well as between the SMA wires and the environment. The device operates without any additional heat transfer medium and cools the heat source directly, which is an advantage in comparison to conventional cooling systems. The design of this complex device in an efficient manner requires a model approach, capable of predicting the system parameters cooling power, mechanical work and coefficient of performance under various operating conditions. The developed model consists of a computationally efficient, thermo-mechanically coupled and energy based SMA model, a model of the system kinematics and a heat transfer model. With this approach, the complete cooling system can be simulated, and the required number of SMA wires as well as the mechanical power can be predicted in order to meet the system requirements. Based on the simulation results a first prototype of the elastocaloric cooling system is realized.


2020 ◽  
Vol 3 (1) ◽  
pp. 116-127
Author(s):  
Maciej Bernacki ◽  
Piotr Kaminski

AbstractThe paper presents and describes cooling systems mainly used in industrial plants specialized in production based on injection moulding machines. Each solution is rated taking into account investment costs, technical complexity, exploitation costs and system flexibility in general. With regard to dynamically changing law regulations linked to refrigeration installations, mainly F-Gases Act, during optimal system selection new restrictions were respected. This approach ensures long-term exploitation without additional complications. The paper contains characteristics of cooled facility, i.e. production plastic plant using injection moulding machines, presents specifics for this type of application where two extremely different cooling processes are placed in parallel. One task is heat collection from injection moulds to ensure short production time and produced details recurrence, the second is keeping hydraulic oil temperature between temperature limits – this process ensures proper oil viscosity and prevents its premature wear.


2020 ◽  
pp. 75-86
Author(s):  
Sergio Antonio Camargo ◽  
Lauro Correa Romeiro ◽  
Carlos Alberto Mendes Moraes

The present article aimed to test changes in cooling water temperatures of males, present in aluminum injection molds, to reduce failures due to thermal fatigue. In order to carry out this work, cooling systems were studied, including their geometries, thermal gradients and the expected theoretical durability in relation to fatigue failure. The cooling system tests were developed with the aid of simulations in the ANSYS software and with fatigue calculations, using the method of Goodman. The study of the cooling system included its geometries, flow and temperature of this fluid. The results pointed to a significant increase in fatigue life of the mold component for the thermal conditions that were proposed, with a significant increase in the number of cycles, to happen failures due to thermal fatigue.


2020 ◽  
Vol 67 (1) ◽  
pp. 42-47
Author(s):  
Anatoliy I. Sopov ◽  
Aleksandr V. Vinogradov

In power transformers, energy losses in the form of heat are about 2 percent of their rated power, and in transformers of large power centers reach hundreds of kilowatts. Heat is dissipated into the environment and heats the street air. Therefore, there is a need to consume this thermal energy as a source of heat supply to nearby facilities. (Research purpose) To develop methods and means of using excess heat of power transformers with improvement of their cooling system design. (Materials and methods) The authors applied following methods: analysis, synthesis, comparison, monographic, mathematical and others. They analyzed various methods for consuming excess heat from power transformers. They identified suitable heat supply sources among power transformers and potential heat consumers. The authors studied the reasons for the formation of excess heat in power transformers and found ways to conserve this heat to increase the efficiency of its selection. (Results and discussion) The authors developed an improved power transformer cooling system design to combine the functions of voltage transformation and electric heating. They conducted experiments to verify the effectiveness of decisions made. A feasibility study was carried out on the implementation of the developed system using the example of the TMG-1000/10/0.4 power transformer. (Conclusions) The authors got a new way to use the excess heat of power transformers to heat the AIC facilities. It was determined that the improved design of the power transformer and its cooling system using the developed solutions made it possible to maximize the amount of heat taken off without quality loss of voltage transformation.


2021 ◽  
Vol 2 (1) ◽  
pp. 1-25
Author(s):  
Srinivasan Iyengar ◽  
Stephen Lee ◽  
David Irwin ◽  
Prashant Shenoy ◽  
Benjamin Weil

Buildings consume over 40% of the total energy in modern societies, and improving their energy efficiency can significantly reduce our energy footprint. In this article, we present WattScale, a data-driven approach to identify the least energy-efficient buildings from a large population of buildings in a city or a region. Unlike previous methods such as least-squares that use point estimates, WattScale uses Bayesian inference to capture the stochasticity in the daily energy usage by estimating the distribution of parameters that affect a building. Further, it compares them with similar homes in a given population. WattScale also incorporates a fault detection algorithm to identify the underlying causes of energy inefficiency. We validate our approach using ground truth data from different geographical locations, which showcases its applicability in various settings. WattScale has two execution modes—(i) individual and (ii) region-based, which we highlight using two case studies. For the individual execution mode, we present results from a city containing >10,000 buildings and show that more than half of the buildings are inefficient in one way or another indicating a significant potential from energy improvement measures. Additionally, we provide probable cause of inefficiency and find that 41%, 23.73%, and 0.51% homes have poor building envelope, heating, and cooling system faults, respectively. For the region-based execution mode, we show that WattScale can be extended to millions of homes in the U.S. due to the recent availability of representative energy datasets.


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