Optimization of a Thermoelectric Cooler for Time-Varying Heat Load and Sink Temperature

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Matthew R. Pearson ◽  
Charles E. Lents
Keyword(s):  
Heat Load ◽  
Thermal Conductance ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Time Varying ◽  
Worst Case ◽  
Operating Cycle ◽  
Temperature Function ◽  
Thermoelectric Coolers ◽  
A Tec

Thermoelectric coolers (TECs) are solid-state cooling devices that operate on the Seebeck effect. They can be used in electronic cooling applications as well as other refrigeration systems. Among the various factors that affect TEC performance within a system, it has been shown that the thermal conductance is an important parameter, which can also be easily altered during the design of a TEC to deliver optimal TEC performance for a given application. However, these studies have considered only a fixed heat load and heat sink temperature, whereas in many realistic applications these quantities can vary. A procedure has been developed for optimizing the thermal conductance of a TEC based on a typical operating cycle of time-varying heat load and sink temperature, while permitting constraints that ensure that one or more worst-case operating conditions can also be met. This procedure is valid for any arbitrary heat load and sink temperature functions; however, for illustrative purposes, a simple heat load function at fixed sink temperature (and a sink temperature function at fixed heat load) is used. The results show that the optimal conductance can strongly depend on the operating cycle, and the corresponding reduction in electrical input work (and corresponding increase in net coefficient of performance (COP)) can be significant.

Optimization of a Thermoelectric Cooler for Time-Varying Heat Load and Sink Temperature

2013 ◽  
Author(s):  
Matthew R. Pearson ◽  
Charles E. Lents
Keyword(s):  
Heat Load ◽  
Thermal Conductance ◽  
Electronics Cooling ◽  
Operating Conditions ◽  
Time Varying ◽  
Worst Case ◽  
Operating Cycle ◽  
Temperature Function ◽  
Thermoelectric Coolers ◽  
A Tec

Thermoelectric coolers (TECs) are solid-state cooling devices that operate on the Seebeck effect. They can be used in electronics cooling applications as well as other refrigeration systems. Among the various factors that affect TEC performance within a system, it has been shown that the thermal conductance is an important parameter which can also be easily altered during the design of a TEC to deliver optimal TEC performance for a given application. However, these studies have considered only a fixed heat load and heat sink temperature, whereas in many realistic applications these quantities can vary. A procedure has been developed for optimizing the thermal conductance of a TEC based on a typical operating cycle of time-varying heat load and sink temperature, while permitting constraints that ensure that one or more worst-case operating conditions can also be met. This procedure is valid for any arbitrary heat load and sink temperature functions; however, for illustrative purposes, a simple heat load function at fixed sink temperature (and a sink temperature function at fixed heat load) are used. The results show that the optimal conductance can strongly depend on the operating cycle, and the corresponding reduction in electrical input work (and corresponding increase in net COP) can be significant.

scholarly journals Гибридные режимы работы термоэлектрических модулей

2022 ◽  
Vol 56 (1) ◽  
pp. 13
Author(s):  
И.А. Драбкин ◽  
Л.Б. Ершова
Keyword(s):  
Cooling Capacity ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Large Temperature ◽  
Hybrid Mode ◽  
Cooling Mode ◽  
Thermoelectric Coolers ◽  
General Cooling ◽  
Maximum Coefficient

It is suggested that thermoelectric coolers designing should not be limited to the extreme modes of their operation. In some cases, it is convenient to use the so called hybrid modes - a combination of the extreme mode of maximum coefficient of performance for large temperature differences and a general cooling mode for small ones. The proposed hybrid mode makes it possible to control the cooling capacity of the module and not to confine this value to that under the extreme operating conditions, the maximum coefficient of performance in particular.

scholarly journals Looking for Energy Losses of a Rotary Permanent Magnet Magnetic Refrigerator to Optimize Its Performances

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4388 ◽  
Author(s):  
Angelo Maiorino ◽  
Antongiulio Mauro ◽  
Manuel Gesù Del Duca ◽  
Adrián Mota-Babiloni ◽  
Ciro Aprea
Keyword(s):  
Heat Load ◽  
Eddy Currents ◽  
Extensive Study ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Heat Transfer Fluid ◽  
Fluid Distribution ◽  
Energy Losses ◽  
Rotary Valve ◽  
Magnetic Refrigerator

In this paper, an extensive study on the energy losses of a magnetic refrigerator prototype developed at University of Salerno, named ‘8MAG’, is carried out with the aim to improve the performance of such a system. The design details of ‘8MAG’ evidences both mechanical and thermal losses, which are mainly attributed to the eddy currents generation into the support of the regenerators (magnetocaloric wheel) and the parasitic heat load of the rotary valve. The latter component is fundamental since it imparts the direction of the heat transfer fluid distribution through the regenerators and it serves as a drive shaft for the magnetic assembly. The energy losses concerning eddy currents and parasitic heat load are evaluated by two uncoupled models, which are validated by experimental data obtained with different operating conditions. Then, the achievable coefficient of performance (COP) improvements of ‘8MAG’ are estimated, showing that reducing eddy currents generation (by changing the material of the magnetocaloric wheel) and the parasitic heat load (enhancing the insulation of the rotary valve) can lead to increase the COP from 2.5 to 2.8 (+12.0%) and 3.0 (+20%), respectively, and to 3.3 (+32%), combining both improvements, with an hot source temperature of 22 °C and 2 K of temperature span.

scholarly journals Improving Heat Transfer from Peltier Devices Used in an Atmospheric Water Generation

2021 ◽  
Vol 6 (3) ◽  
pp. 170-175
Author(s):  
Mark Summers ◽  
Bahram Asiabanpour
Keyword(s):  
Heat Transfer ◽  
Convection Heat Transfer ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Conductive Heat ◽  
Vapor Compression ◽  
Solar Panels ◽  
Atmospheric Water ◽  
Thermoelectric Coolers ◽  
Phase Change Heat Transfer

Present Atmospheric Water Generation (AWG) systems are useful for providing water in areas with limited water supplies. Many industrial AWG systems use VCR (vapor-compression refrigeration) to achieve a large amount of cooling to extract liquid water out of the air.  These systems require large amounts of energy to operate, usually in the form of diesel or AC-powered generators.  The systems also have many moving parts that require maintenance and use refrigerants that can leak and cause problems with the environment. An alternative AWG solution is to use DC-powered Peltier devices (thermoelectric coolers) to reduce the temperature of condensation plates to extract water from the air.  This solution eliminates the issues with traditional industrial AWG systems since the Peltier devices are solid-state, have very long mean-time between failure (MTBF) performance, and can be powered by solar panels that eliminate the need to burn hydrocarbon-based fuels or have access to a reliable power grid.  Also eliminated is the need to use chlorofluorocarbon (CFC) or hydrochlorofluorocarbons (HCFC) refrigerants that have been shown to deplete the ozone layer. This paper will present methods to improve the efficiency of the thermoelectric coolers by more efficiently extracting heat from the hot side of the device.  This efficiency will be quantified by evaluating the coefficient of performance (COP) of the thermoelectric cooler under the various operating conditions.  Different combinations of conductive heat transfer using aluminium heatsinks, convection heat transfer using forced airflow, and phase change heat transfer using copper heat pipes filled with distilled water will be investigated and evaluated.

scholarly journals Selection of Heat Pump Capacity Used at Thermal Power Plants under Electricity Market Operating Conditions

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 226
Author(s):  
Milana Treshcheva ◽  
Irina Anikina ◽  
Vitaly Sergeev ◽  
Sergey Skulkin ◽  
Dmitry Treshchev
Keyword(s):  
Electric Power ◽  
Heat Pump ◽  
Heat Load ◽  
Power Plants ◽  
Thermal Power ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Energy Resources ◽  
Thermal Power Plants ◽  
Maximum Heat

The percentage of heat pumps used in thermal power plants (TPPs) in the fuel and energy balance is extremely low in in most countries. One of the reasons for this is the lack of a systematic approach to selecting and justifying the circuit solutions and equipment capacity. This article aims to develop a new method of calculating the maximum capacity of heat pumps. The method proposed in the article has elements of marginal analysis. It takes into account the limitation of heat pump capacity by break-even operation at electric power market (compensation of fuel expenses, connected with electric power production). In this case, the heat pump’s maximum allowable capacity depends on the electric capacity of TPP, electricity consumption for own needs, specific consumption of conditional fuel for electricity production, a ratio of prices for energy resources, and a conversion factor of heat pump. For TPP based on combined cycle gas turbine (CCGT) CCGT-450 with prices at the Russian energy resources markets at the level of 2019, when operating with the maximum heat load, the allowable heat pump capacity will be about 50 MW, and when operating with the minimum heat load—about 200 MW.

Efficient Analysis of a Catenary Riser

2006 ◽  
Author(s):  
Elizabeth Passano ◽  
Carl M. Larsen
Keyword(s):  
Operating Conditions ◽  
Stochastic Simulations ◽  
Worst Case ◽  
Nonlinear Structure ◽  
Tension Response ◽  
Extreme Response ◽  
Analysis Strategies ◽  
Low Tension ◽  
Term Response

The paper deals with the challenge of predicting the extreme response of catenary risers, a topic of both industry and academic interest. Large heave motions introduced at the upper end of a catenary riser can lead to compression and large bending moments in the region immediately above the touch down area. In the worst case, dynamic beam buckling may occur. The focus of the paper will be on understanding the riser behaviour in extreme, low-tension response and in establishing suitable analysis strategies to predict the extreme response. Results from long nonlinear stochastic simulations of many sea states with varying environmental and operating conditions may be combined to describe the long-term response of a nonlinear structure such as a catenary riser. However, this theoretically straight-forward approach is very demanding computationally and ways to limit the extent of nonlinear stochastic simulations are therefore sought. The usefulness of simpler methods such as regular wave analysis to improve understanding of the physical behaviour and to aid in concentrating the nonlinear simulations to where they are most useful, will be demonstrated.

Numerical Optimization of the Thermoelectric Cooling Devices

2005 ◽  
Author(s):  
B. Abramzon
Keyword(s):  
Electric Current ◽  
Optimum Design ◽  
Random Search ◽  
Thermal Conductance ◽  
Physical Parameters ◽  
Thermoelectric Cooling ◽  
Thermoelectric Coolers ◽  
Independent Variables ◽  
Cooling Devices ◽  
Optimization Search

The present study proposes the unified numerical approach to the problem of optimum design of the thermoelectric devices for cooling electronic components. The method is illustrated with several examples which are based on the standard mathematical model of a single-stage thermoelectric cooler with constant material properties. The model takes into account the thermal resistances from the hot and cold sides of the TEC. Values of the main physical parameters governing the TEC performance (Zeebeck coefficient, electrical resistance and thermal conductance) are derived from the manufacturer catalog data on the maximum achievable temperature difference, and the corresponding electric current and voltage. The independent variables for the optimization search are the number of the thermoelectric coolers, the electric current and the cold side temperature of the TEC. The additional independent variables in other cases are the number of thermoelectric couples and the height-to area ratio of the thermoelectric pellet. The objective for the optimization search is the maximum of the total cooling rate or maximum of COP. In the present study, the problems of optimum design of thermoelectric cooling devices are solved using the so-called Multistart Adaptive Random Search (MARS) method [16].

Studying Systems of Stabilization of Supports in Hydrostatic Machine Tool

2012 ◽  
Vol 622-623 ◽  
pp. 489-493
Author(s):  
Iskander Beisembetov ◽  
Sabyi Ussupov ◽  
Bakhyt Absadykov ◽  
Beken Arymbekov ◽  
Birzhan Bektibay
Keyword(s):  
Film Thickness ◽  
Machine Tools ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Operational Parameters ◽  
Automatic Stabilization ◽  
Design Elements ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Automatic Control Systems

Development relevance to improve the operational parameters of the support units of machine tools in their design elements is introduced that increase the rigidity of the components, their carrying capacity, damp occurring vibrations in the process, the coefficient of performance (COP), smoothness of motion, positioning accuracy, reducing the wear of their working surfaces and maintain the original accuracy. A number of engineering development [1], [2], aimed at improving the above characteristics of the machine by changing and improving design of reference nodes used in these rails rolling bearings, aerostatic and hydrostatic guides, as well as the use of automatic control systems of its basic parameters, determine its quality. However, in some operating conditions in which errors occur, mainly due to the instability of oil-film thickness (gap) between the mobile and immobile elements of the hydrostatic bearing. For high accuracy requirements it will negatively affect the quality of machined parts and equipment performance. On this basis, it becomes apparent urgency of the problem of automatic stabilization of oil-film thickness (gap) in the IR. To ensure high precision equipment to improve power system hydrostatic bearing units of machine tools. This, in turn, creates the prerequisite for the development of stabilization systems of the gap in the hydrostatic bearing, with the help of which the thickness of oil layer in them would be kept constant even with significant dynamic load on the support.

Using Sliding Mode Control to Adjust Drum Level of a Boiler Unit With Time Varying Parameters

2010 ◽  
Author(s):  
Hamed Moradi ◽  
Firooz Bakhtiari-Nejad ◽  
Majid Saffar-Avval ◽  
Aria Alasty
Keyword(s):  
Water Level ◽  
Transfer Functions ◽  
Sliding Mode ◽  
Operating Conditions ◽  
Model Parameters ◽  
Feed Water ◽  
Time Varying ◽  
Boiler Unit ◽  
Varying Parameters ◽  
Time Varying Parameters

Stable control of water level of drum is of great importance for economic operation of power plant steam generator systems. In this paper, a linear model of the boiler unit with time varying parameters is used for simulation. Two transfer functions between drum water level (output variable) and feed-water and steam mass rates (input variables) are considered. Variation of model parameters may be arisen from disturbances affecting water level of drum, model uncertainties and parameter mismatch due to the variant operating conditions. To achieve a perfect tracking of the desired drum water level, two sliding mode controllers are designed separately. Results show that the designed controllers result in bounded values of control signals, satisfying the actuators constraints.

Introduction of the Taurus™ 65 Industrial Gas Turbine for Power Generation

2008 ◽  
Author(s):  
George Rocha ◽  
Simon Reynolds ◽  
Theresa Brown
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Electrical Power ◽  
Field Evaluation ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Liquid Fuels ◽  
Operating Cycle ◽  
Product Experience ◽  
Exhaust Heat

Solar Turbines Incorporated has combined proven technology and product experience to develop the new Taurus 65 gas turbine for industrial power generation applications. The single-shaft engine is designed to produce 6.3 megawatts of electrical power with a 33% thermal efficiency at ISO operating conditions. Selection of the final engine operating cycle was based on extensive aerodynamic-cycle studies to achieve optimum output performance with increased exhaust heat capacity for combined heat and power installations. The basic engine configuration features an enhanced version of the robust Centaur®50 air compressor coupled to a newly designed three-stage turbine similar to the Taurus 70 turbine design. Advanced cooling technology and materials are used in the dry, lean-premix annular combustor, consistent with Solar’s proven SoLoNOx™ combustion technology, capable of reducing pollutant emissions while operating on standard natural gas or diesel liquid fuels. Like the Titan™ 130 and Taurus 70 products, a traditional design philosophy has been applied in development of the Taurus 65 gas turbine by utilizing existing components, common technology and product experience to minimize risk, lower cost and maximize durability. A comprehensive factory test plan and extended field evaluation program was used to validate the design integrity and demonstrate product durability prior to full market introduction.

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