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The first commercially available plug-in hybrid electric vehicle (PHEV), the General Motors (GM) Volt, was introduced into the market in mid-December 2010. The Volt uses a series-split powertrain architecture, which provides benefits over the series architecture that typically has been considered for use in electric-range extended vehicles (EREVs). A specialized EREV powertrain, called the Voltec, drives the Volt through its entire range of speed and acceleration with battery power alone and within the limit of battery energy, thereby displacing more fuel with electricity than a PHEV, which characteristically blends electric and engine power together during driving. This paper assesses the benefits and drawbacks of these two different plug-in hybrid electric architectures (series versus series-split) by comparing component sizes, system efficiency, and fuel consumption over urban and highway drive cycles.

The Aircraft Interiors subscription addresses the specialized needs and mechanical requirements for aircraft cabin interior design. The application of these standards will aid in the efficient and cost-effective manufacture of quality aircraft components. The standards in this resource include: Glossary of Technical and Physiological Terms Related to Aerospace Oxygen Systems Flight Deck Layout and Facilities Numeral, Letter and Symbol Dimensions for Aircraft Instrument Displays Oxygen Equipment for Aircraft Human Interface Design Methodology for Integrated Display Symbology

Climate control is a defining vehicle attribute and is associated with brand image. Thermal performance is critical to customer satisfaction. The primary objective is to deliver occupant safety and thermal comfort at minimum energy consumption, yet the system has strong design interaction with other vehicle systems. Noise, Air Quality, and Energy ace are just a few of the recent advances.

Climate control is a defining vehicle attribute and is associated with brand image. Thermal performance is critical to customer satisfaction. The primary objective is to deliver occupant safety and thermal comfort at minimum energy consumption, yet the system has strong design interaction with other vehicle systems. Noise, Air Quality, and Energy ace are just a few of the recent advances.

Abstract To reduce fuel consumption and carbon dioxide (CO2) emissions from mobile air conditioning (A/C) systems, “U.S. Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy Standards” identified solar/thermal technologies such as solar control glazings, solar reflective paint, and active and passive cabin ventilation in an off-cycle credit menu. National Renewable Energy Laboratory (NREL) researchers developed a sophisticated analysis process to calculate U.S. light-duty A/C fuel use that was used to assess the impact of these technologies, leveraging thermal and vehicle simulation analysis tools developed under previous U.S. Department of Energy projects. Representative U.S. light-duty driving behaviors and weighting factors including time-of-day of travel, trip duration, and time between trips were characterized and integrated into the analysis.

Abstract The most important and most easily damaged part of a revolving vane (RV) compressor is the vane. The friction loss of the vane determines the service life and maintenance cost of the RV compressor to a certain extent. To improve the efficiency and prolong the service life of the RV compressor, it is of great significance to analyze the dynamics of the vane and reduce the friction loss of the vane. In this article, a scheme is proposed to reduce the friction at the vane’s sides for the RV compressor. In the proposed scheme, the force acting on the vane tip due to the cylinder inertia is eliminated by driving the rotor and cylinder externally and separately; thus the friction loss at the vane’s sides is reduced. Calculations show that eliminating the effect of cylinder inertia can reduce the friction loss at the vane’s sides from 44.9 W to 24.7 W.

Create a method/procedure to measure build up and concentration of CO2 in the passenger compartment.

This SAE standard applies to compressor lubricants intended for aftermarket use in the refrigerant circuit of vehicle air-conditioning systems. This standard does not grant the user to qualify a lubricant as OEM approved. This SAE Standard is not limited by refrigerant selection, however, only refrigerants identified in SAE 639 may apply for SAE J2911 submission and container labeling.

This document provides guidance for establishing ECS for UA by primarily referencing existing AC-9 documents that apply with some indication how they need to be adapted. The document primarily addresses cooling requirements for UA equipment. Limited information is provided for ECS requirements for future UA that may carry passengers. The document does not intend to provide detail design guidance for all types of UA. This document only provides guidance related to environmental control of onboard equipment, cargo and possible animals and passengers. It does not pertain to the related ground stations that may be controlling the UA.

This standard sets forth the performance and durability requirements for 12-volt, D.C. brush-type electric motors used for automobile Heating, Ventilation, and Air Conditioning (HVAC) blowers and outlines Production Validation and Continuing Conformance testing.

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.

This paper demonstrates that the implementation of Flash Gas Bypass method can improve the performance of conventional direct expansion R134a mobile air-conditioning system with a microchannel evaporator. This method uses flash gas tank after expansion valve to separate and bypass flash refrigerant vapor around the evaporator, and feed the evaporator with only liquid refrigerant. Pressure drop is reduced and refrigerant distribution is significantly improved, resulting in higher evaporator effectiveness and evaporation pressure. Both lower pressure drop and lifted evaporation pressure allows the compressor to work with lower pressure ratio, saving required compressor work. An experimental comparison of the direct expansion system shows that Flash Gas Bypass method increases the cooling capacity and COP at the same time by up to 16% and 11%, respectively.

The subject addressed by this work, currently discussed in Europe following an European Commission inquiry, is the evaluation of the possibility to prevent the MAC (Mobile Air Conditioning) use below 18°C and its benefits in terms of CO2 emissions saving. This strategy, while providing an uncertain fuel consumption saving, has to be faced with basic safety and cabin comfort conditions. The OEMs (Original Equipment Manufacturers) may evaluate to address these concerns by controlling the cabin absolute humidity content. In order to maintain safety it should be acceptable to turn the AC on based on other inputs, such as air distribution modes (defrost or floor/defrost), windshield wiper usage, rear defroster usage, etc. FGA (FIAT Group Automobiles) exploited our proprietary prediction tool to assessing the yearly fuel efficiency that can be achieved in real use by means of the testing results of representative vehicles.

Multiple-ribbed V belts have been widely used in automotive accessory drive systems to transmit power from crankshaft to power steering pump, alternator, and air conditioning (A/C) compressor. Overload under severe environmental conditions can lead to excessive slippage in the belt pulley interface in poorly designed accessory drive systems. This can lead to undesirable noise that increases warranty cost substantially. The mechanisms of this tribology phenomenon, noise features and system response are of utmost interest to the accessory drive system engineers. As accessory belt systems are usually used in ambient condition, the presence of water or moisture on belt is unavoidable under rainy or highly humid conditions. It has been found that the wet friction with negative coefficient of friction (cof)-velocity slope can lead to self-excited vibrations and squeal noise.

The operation of air conditioning (A/C) systems is a significant contributor to the total amount of fuel used by light-and heavy-duty vehicles. Therefore, continued improvement of the efficiency of these mobile A/C systems is important. Numerical simulation has been used to reduce the system development time and to improve the electronic controls, but numerical models that include highly detailed physics run slower than desired for carrying out vehicle-focused drive cycle-based system optimization. Therefore, faster models are needed even if some accuracy is sacrificed. In this study, a validated model with highly detailed physics, the “Fully-Detailed” model, and two models with different levels of simplification, the “Quasi-Transient” and the “Mapped-Component” models, are compared. The Quasi-Transient model applies some simplifications compared to the Fully-Detailed model to allow faster model execution speeds.

Traditional vehicle air conditioning systems condition the entire cabin to a comfortable range of temperature and humidity regardless of the number of passengers in the vehicle. The A/C system is designed to have enough capacity to provide comfort for transient periods when cooling down a soaked car. Similarly for heating, the entire cabin is typically warmed up to achieve comfort. Localized heating and cooling, on the other hand, focuses on keeping the passenger comfortable by forming a micro climate around the passenger. This is more energy efficient since the system only needs to cool the person instead of the entire cabin space and cabin thermal mass. It also provides accelerated comfort for the passenger during the cooling down periods of soaked cars. Additionally, the system adapts to the number of passengers in the car, so as to not purposely condition areas that are not occupied.

The paper presents a semi-empirical model to predict refrigerant and lubricant inventory in both evaporator and condenser of an automotive air conditioning (MAC) system. In the model, heat exchanger is discretized into small volumes. Temperature, pressure and mass inventory are calculated by applying heat transfer, pressure drop and void fraction correlations to these volumes respectively. Refrigerant and lubricant are treated as a zeotropic mixture with a temperature glide. As refrigerant evaporates or condenses, thermophysical properties are evaluated accordingly with the change of lubricant concentration. Experimental data is used to validate the model. As a result, refrigerant and lubricant mass is predicted within 20% in the evaporator. However, in the condenser, lubricant mass was consistently under-predicted while refrigerant mass was predicted within 15% error. Moreover, the lubricant under-prediction becomes more significant at higher Oil Circulation Ratio (OCR).

This paper presents a method of utilizing infrared images to quantify the distribution of liquid refrigerant mass flow rate in microchannel heat exchangers, which are widely used in automobile air conditioning systems. In order to achieve quantification, a relationship is built between the liquid mass flow rate through each microchannel tube and the corresponding air side capacity calculated from the infrared measurement of the wall temperature. After being implemented in a heat exchanger model, the quantification method is validated against experimental data. This method can be used for several types of heat exchangers and it can be applied to various heat exchanger designs.

In last 10 years or so, a number of OEMs are designing vehicles with start-stop function to save energy and to reduce pollution. For these systems, the situations in which air-conditioning systems are used have been changing with a significant increase in adoption of idle-time reduction systems (no idling-system). Blower fan remains operating at idle condition while compressor stops in most cases for these systems. In this case, the air temperature at the vent outlets increases. The increase in the air temperature under range of thermal boundary conditions around the evaporator causes a concern of odor to occur. This paper describes and explains experimental studies on changes in heat and humidity at the air outlets according to the switching operation of compressor and root cause analyses of odor coming from air-conditioning system for vehicles with start-stop function.

The vehicle Heating, Ventilation and Air conditioning (HVAC) system is designed to meet both the safety and thermal comfort requirements of the passengers inside the cabin. The thermal comfort requirement, however, is highly subjective and is usually met objectively by carrying out time dependent mapping of parameters like the velocity and temperature at various in-cabin locations. These target parameters are simulated for the vehicle interior for a case of hot soaking and its subsequent cool-down to test the efficacy of the AC system. Typically, AC performance is judged by air temperature at passenger locations, thermal comfort estimation along with time to reach comfortable condition for human. Simulating long transient vehicle cabin for thermal comfort evaluation is computationally expensive and involves complex cabin material modelling.