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e-Thermal is a vehicle level thermal analysis tool developed by General Motors to simulate the transient performance of the entire vehicle HVAC and Powertrain cooling system. It is currently in widespread (global) use across GM. This paper discusses the details of the air-conditioning module of e-Thermal. Most of the literature available on transient modeling of the air conditioning systems is based on finite difference approach that require large simulation times. This has been overcome by appropriately modeling the components using Sinda/Fluint. The basic components of automotive air conditioning system, evaporator, condenser, compressor and expansion valve, are parametrically modeled in Sinda/Fluint. For each component, physical characteristics and performance data is collected in form of component data standards. This performance data is used to curve fit parameters that then reproduce the component performance.

The significance of thermal management performance in electric vehicles (EVs) has grown considerably, leading to increased complexity in thermal systems and a rapid rise in safety and quality-related concerns. The present real-vehicle-based development methods encounter several constraints in their approach when dealing with highly complex systems. Huge number of verification and validation work To overcome these limitations and enhance the thermal system development process, a novel virtual development environment established using the XiLS (X in the Loop Simulation) methodology. This XiLS methodology basically based on real-time coupling between physical thermal system hardware and analytical models for the other systems of vehicle. To control vehicle model and thermal system, various options were realized through hardware, software and model for VCU (Vehicle control unit) and TMS (Thermal management system) control unit.

Battery electric vehicles (BEVs) are equipped with Mobile Air Conditioning systems (MACs) to ensure a comfortable cabin temperature in all climates and ambient conditions as well as the optional conditioning of the traction battery. An assessment of the global electrical energy consumption of various MACs has been derived, where the basis of the assessment procedure is the climate data GREEN-MAC-LCCP 2007 (Global Refrigerants Energy & Environmental - Mobile Air Condition - Life Cycle Climate Performance) and the improved LCCP2013 (Life Cycle Climate Performance. The percentage driving time during 6 AM and 24 PM is divided into six different temperature bins with the solar radiation and relative humidity for 211 cities distributed over Europe, North, Central, and South America, Asia, South West Pacific, and Africa. The energy consumption of the MACs is determined by a thermal vehicle simulation. In this work, four different MACs are simulated and compared.

Regarding the prevention of global warming and ozone layer depletion to protect the global environment, energy conservation and disuse of CFCs are among the recent industrial requirements. An ejector cycle can save power by eliminating expansion energy loss in the conventional vapor compression refrigeration cycle, which uses an expansion valve, and using the otherwise lost energy as compressor power. This technology is useful for almost all kinds of refrigerating and air-conditioning systems, but has not yet been developed to a practical level anywhere in the world. We have developed a practical ejector cycle technology and successfully commercialized it for the first time in the world, as an ejector cycle refrigerator that drastically improves refrigerating capacity and power efficiency while substantially reducing system weight, in comparison with refrigerators using the conventional vapor compression cycle.

The discharge valve impact force on the valve retainer and valve plate play a critical role on the NVH characteristics of the wobble plate compressor. Another contributing factor to compressor NVH is in-cylinder bore over-pressure. In order to improve the NVH characteristics, a reduction in the valve impact forces and in-cylinder over-pressure is essential. The focus of this paper will be a new valve plate assembly change utilizing a unique design arrangement. This new design change significantly improved compressor NVH characteristics due to reduction in the the valve impact force as well as in-cylinder over-pressure. A slight reduction in compressor cooling capacity was observed. Research efforts are continuing to overcome this reduction.

The operational characteristics of low noise, low vibration, and inherent reliability of the Stirling engine make it highly desirable as the power source for a total energy system in a motor home. In this application, the Stirling engine has made possible the development of new electrical, heating, and air conditioning systems offering much higher levels of comfort, convenience, and reliability to the motor home user. As an auxiliary power source in the motor home, the Stirling engine generates electricity to operate all-electric appliances and recharge batteries, provides efficient hot water baseboard heat to the interior of the motor home, and eliminates the need for LP gas usage in the motor home. And integrated into the cooling system for the Stirling engine is a new, low noise air conditioning system.

The following presents in detail one full-scale automobile wind tunnel and two thermodynamic wind tunnels, their development and integration for an economic solution. Information is given on machinery equipment, air speed and temperature ranges and measurement-possibilities. Two thermodynamic test stands, smaller wind tunnels, are described. The first one is designed for measurements on heat exposed parts of the car, in particular engine cooling. The second one is able to simulate all climatic conditions and was designed for solving problems concerning heating and air conditioning systems. The presentation concludes with reports on initial experiences with these test facilities.

A new and unique electric vehicle powertrain model based on bidirectional power flow for propel and regenerative brake power capture is developed and applied to production battery electric vehicles. The model is based on a Willans line model to relate power input from the battery and power output to tractive effort, with one set of parameters (marginal efficiency and an offset loss) for the bidirectional power flow through the powertrain. An electric accessory load is included for the propel, brake and idle phases of vehicle operation. In addition, regenerative brake energy capture is limited with a regen fraction (where the balance goes to friction braking), a power limit, and a low-speed cutoff limit. The purpose of the model is to predict energy consumption and range using only tractive effort based on EPA published road load and test mass (test car list data) and vehicle powertrain parameters derived from EPA reported unadjusted UDDS and HWFET energy consumption.

Before considering the future of aircraft environmental control systems (ECS's), a review of the relatively short history of this field would be valuable in understanding the present situation. Therefore, this paper notes many of the significant developments in commercial aircraft air-cycle refrigeration and in cabin environmental control. The evolution leading to the great variety of air-cycle systems now in production, or under development, is discussed along with a generic comparison of the merits of the various system types and some reasons for their selection. Constraints on air conditioning system development imposed by the airline operators, aircraft manufacturers, and regulatory agencies are touched upon as significant to charting the future direction of air conditioning system design. Finally, several directions that could be taken in future design are briefly commented upon.

The purpose of this paper is to define the meaning of truck air conditioning, to acquaint the various truck users with the historical development of truck air conditioning, to dwell briefly on basic system operation, and to make a cursory comparison of automobile and truck air conditioning system requirements. These requirements include structural durability, reduced weight, and ease of serviceability.

Over the course of the past decade, the automotive industry has made efforts to reduce the depth of the brazed aluminum, louver fin evaporators typically used in the air conditioning system for automobiles by increasing their compactness. Increasing fin and louver densities have led to the possibility of condensate affecting the air side performance of automotive evaporators. Condensate can “bridge” the space between two adjacent fins or louvers. Condensate bridging of the fins or louvers can alter the flow of air through the evaporator, causing a change in the heat transfer and friction characteristics. This study attempts to quantify these changes and determine which parameters will have an impact on them. Wind tunnel tests measuring the air side sensible heat transfer coefficient and pressure drop were conducted to examine how the air side heat transfer and friction characteristics of automotive evaporators are changed by the presence of condensate.

In the absence of recycling, water represents over 90% of the life-support consumables for a human spacecraft. In addition, over 90% of the waste water generated can be classified as either moderately or slightly contaminated (e.g. shower water, condensate from the air-conditioning system, etc..) The ability to recover potable water from moderately contaminated waste water hence enables significant savings to be made in resupply costs. A development model of such a water-recovery system, based on membrane technology, has been produced and tested using ‘real waste water’ based on used shower water. Results indicate some 95% recovery of potable water meeting European Space Agency (ESA) standards, with total elimination of microbial contaminants such as bacteria, spores and viruses. A second phase focused on improving the functioning of the breadboard and to test it in a long duration test (5-6 months).

This paper provides a focus on the R & D of solid sorption coolers and heat pumps made in the Luikov Heat & Mass Transfer Institute (CIS Countries Association “Heat Pipes”) under Thermacore, Inc. Agreement. Commercial and space applications of sorbent systems offer an attractive alternative to compression systems and liquid sorption system in cooling, heating and air conditioning. The key elements of solid sorption machines are the chemical compressors-adsorbers. Two categories of solid sorption system are analyzed: adsorbents (MgA, NaX zeolites, carbon fibre “Busofit” with water, acetone, NH3), and compounds with chemical reaction and physical adsorption (CaCL2+ carbon fibre “Busofit” with NH3). These systems differ in one very important aspect: the adsorption equilibrium is bivariant, chemical reaction is monovariant. Some promising results with zeolite-water and NH3, “Busofit” with acetone and NH3 are received.

In the port injected Spark Ignition (SI) engine, the single greatest part load efficiency reducing factor are energy losses over the throttle valve. The need for this throttle valve arises from the fact that engine power is controlled by the amount of air in the cylinders, since combustion occurs stoichiometrically in this type of engine. In WEDACS (Waste Energy Driven Air Conditioning System), a technology patented by the Eindhoven University of Technology, the throttle valve is replaced by a turbine-generator combination. The turbine is used to control engine power. Throttling losses are recovered by the turbine and converted to electrical energy. Additionally, when air expands in the turbine, its temperature decreases and it can be used to cool air conditioning fluid. As a result, load of the alternator and air conditioning compressor on the engine is decreased or even eliminated, which increases overall engine efficiency.

Noise, vibration and Harshness in the automotive industry became important mainly because the development of modern automobiles and the increased of customer demands for quieter vehicles and with comfortable vibration levels. The sources of vibration and noise inside the vehicle are caused by the engine, tires, transmission systems, suspension, air conditioning, among others. In this work, vibroacoustic transfer function is obtained to analyze the internal noise in two sport utility vehicle with distinctive silhouette. Furthermore, it was analyzed the influence of elastomeric bushings rigidity of the damper in reducing internal noise and vibration and the effect of adding mass in some framework positions for attenuation of vibration peaks due to structural resonance.

Accuracy of numerical simulation has to be evaluated through the actual phenomenon such as experiment or measurement and then it can be employed to design the air-conditioning system of car cabin at the development phase. Scaled model of vehicle cabin was created by the Society of Automotive Engineers of Japan (JSAE) and the experiment was performed to obtain the detailed information of heat transfer characteristics inside the cabin under the non-isothermal condition. The sheet heaters were put to the inner surface of the acrylic cabin and they supplied certain amount of heat. The temperatures of inner and outer surface and air were measured to evaluate the thermal environment of the cabin. The results lead to enhancement of the data of the standard model of the cabin.

Following the previous reports, ventilation characteristics in automobile was investigated by using a half-scale car model which was created by the Society of Automotive Engineers of Japan (JSAE). In the present study, the ventilation mode of the cabin was foot mode which was the ventilation method for using in winter season. Supplied air was blown from the supply openings under the dashboard to the rear of the model via the driver's foot region in this mode. The experiment was performed in order to obtain accurate data about the airflow properties equipped with particle image velocimetry (PIV). Our experimental data is to be shared as a standard model to assess the environment within automobiles. The data is also for use in computational fluid dynamics (CFD) benchmark tests in the development of automobile air conditioning, which enables high accuracy prediction of the interior environment of automobiles.

This work shows the “Value Methodology” application looking for to identify new alternatives for vehicular electrical energy system (battery, starter, generator, coils etc.). These alternatives must be feasible to the nowadays automobiles system. The electrical system studied in this job points out to engine with its main assembled options, or accessories, as air-conditioning, hydraulic power system (HPS), electrical lifter window, a thief deterrents alarm, door lockers, etc. Heavy electrical traffic conditions, which demand more energy, representing a bigger electrical charge, are being considered in this analysis. The main focus of this job is to show the internal parts reduction, meaning a better final cost to suppliers and carmakers, and consequently a better vehicle performance. Improvements achieved through this study must be appreciated.

The air conditioning systems of a fleet of sixteen (16) globally distributed vehicles have been retrofit to HFC-134a and ester-based lubricants. The variables of a generic flush-type retrofit procedure have been systematically changed. The effects of compressor condition (new or pre-conditioned), desiccant type (re-used XH-5 or new XH-7), evacuation times, and charge of mineral oil and HFC-134a were examined, in an attempt to better understand the significance of these specific variables on performance and durability of mobile air conditioning systems under retrofit conditions. Initial performance, measured qualitatively by cooling performance and quantitatively by compressor clutch cycling, is judged to be acceptable. Additional information will be provided, as available, on long-term durability of these systems.