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Viewing 151 to 180 of 9831
2014-04-01
Technical Paper
2014-01-0443
Michael Tschirhart, Kathleen Ku
Abstract The vehicle environment is known to be a demanding context for efficiently displaying information to the driver. Research in typography reveals some factors that influence reading performance measures, but there is limited research on the influence of typographic design elements in a driver-vehicle interface on user performance with a simulated driver task. Participants in these studies completed a set of vehicle infotainment tasks that involved a text-based item search in a custom-designed interface that employed a family of Helvetica Neue fonts, in a static environment and a driving simulator environment. Analysis of the data from the two studies reveals a modest but statistically significant effect of font on certain driving-related task performance measures. In both studies, fonts with intermediate values of character width and line thickness were associated with the best performance on a simulated driving task. The results of this study suggest that using typefaces with intermediate values of certain intrinsic design factors may serve as a simple and effective means of improving vehicle user interfaces.
2014-04-01
Technical Paper
2014-01-0713
Guangning(Gary) Gao
Abstract Distance to empty (DTE) estimation is an important factor to electric vehicle (EV) applications due to its limited driving range. The DTE calculation is based on available energy of the battery and power usage by the powertrain components (e.g. electric motor) and climate control components (e.g. PTC heater and electric AC compressor). The conventional way of estimating the DTE is to treat the power consumed by the climate control system the same as the power by the powertrain for either instantaneous or rolling average estimation. The analysis in this study shows that the power consumption by the climate control system should be estimated based on the current ambient conditions and driver's input instead of using the recorded data from the past driving cycles. The climate control should also be considered separately from the powertrain in power usage rolling average calculation, which results in improvements in DTE estimation especially for extreme hot and cold conditions. Additionally, the climate control power consumption shows unique characteristics during the initial period of cabin climate control.
2014-04-01
Technical Paper
2014-01-0707
Nicolas F. Ponchaut, Francesco Colella, Ryan Spray, Quinn Horn
Abstract The emergence of Plug-in hybrid electric vehicles (PHEVs) and electric vehicles (EVs) as a viable means of transportation has been coincident with the development of lithium-ion battery technology and electronics that have enabled the storage and use of large amounts of energy that were previously only possible with internal combustion engines. However, the safety aspects of using these large energy storage battery packs are a significant challenge to address. For example an unintentional sudden release of energy, such as through a thermal runaway event, is a common concern. Developing thermal management systems for upset conditions in battery packs requires a clear understanding of the heat generation mechanisms and kinetics associated with the failures of Li-ion batteries. Although every effort is made to avoid thermal runaway situations, there can still be upset and unforeseen instances where a cell or a pack would reach a sufficiently high temperature to initiate exothermic reaction(s) that often are initially slow to develop.
2014-04-01
Technical Paper
2014-01-0706
Yang Zou, Huize Li, Predrag Hrnjak
Abstract Lubricant in compressor usually flows out with refrigerant. Thus, it is evitable for lubricant to be present in the heat exchanger, which significantly affects the heat exchanger performance. This paper is to investigate the effects of PAG oil on R134a distribution in the microchannel heat exchanger (MCHX) with vertical headers and to provide a tool to model R134a (with oil) distribution and its effects on MCHX capacity. The flow configuration in MCHX under the heat pump mode of the reversible system is mimicked in the experimental facility: refrigerant-oil mixture is fed into the test header from the bottom pass and exits through the top pass. It is found that a small amount of oil (OCR=0.5%) worsen the distribution. But further increasing OCR to 2.5% and 4.7%, the distribution becomes better. However, in a multi-pass microchannel heat exchanger model (considering oil effects), though the distribution is better and the capacity is closer to the uniform distribution case, the MCHX capacity decreases with respect to OCR because oil affects the heat transfer and pressure drop in the microchannel heat exchanger.
2014-04-01
Technical Paper
2014-01-0705
Gursaran D. Mathur
Abstract Experimental studies have been conducted to determine the energy stored in vehicle's Cockpit Module (CPM) at high ambient and at high solar heat loads for a MY2012 production vehicle. Detailed analysis has been done in this paper to show the influence of energy stored in various components (e.g., Instrument panel, HVAC system, heat exchanger, wire harness, etc.) contained within the CPM unit. Experiments were conducted to show the amount of energy stored at high ambient and solar conditions.
2014-04-01
Technical Paper
2014-01-0712
Jae Yeon Kim, Yong Nam Ahn, Shim Rok, Su Whan Kim, Wan Je Cho, Jy Choi, Hyun Keun Shin, Sang Ok Lee
Abstract In order to improve the fuel consumption ratio of the vehicle, a great deal of research is being carried out to improve air-conditioning efficiency. Increasing the efficiency of the condenser is directly connected to the power consumption of the compressor. This paper describes an experimental method of using an additional water-cooled condenser to reduce power consumption and decrease discharge pressure of the air-conditioning system. First, the principle of a combined cooling (water + air) method was evaluated theoretically. Next, experimental proof was conducted with the additional water-cooled condenser. The shape and structure is similar to the plate type of the transmission oil cooler used in a radiator. Through a number of tests, it was found that it is possible is to reduce power consumption of compressor by decreasing discharge pressure.
2014-04-01
Technical Paper
2014-01-0709
Kesav Kumar Sridharan, Ravish Masti, Ravi Kumar, Jiancheng Xin, Wendong Wang, Henry Kong
Abstract In hybrid electric vehicles (HEVs) and full electric vehicles (EVs), efficient electrical power management with proper supply of power at the required voltage levels is essential. A DC (Direct Current)-DC converter is one of the key electrical units in a HEV/EV. The DC-DC converter dealt in the present work is intended to create the DC voltages necessary to power the accessories. The electronic circuit in this DC-DC converter consists of high power devices like Metal-Oxide Semiconductor Field-Effect Transistors (MOSFETs), inductors, transformers, etc. mounted on a printed circuit board (PCB). The DC-DC converter interacts with a high voltage battery pack and supplies a low voltage power to the accessory battery. Due to this power handling operation, the devices in the convertor experience high temperatures. The temperature rise of the devices beyond the permissible limits could be detrimental to an efficient and safe operation of the converter. This paper deals with a robust and optimal thermal design of an air-cooled DC-DC Converter in order that the temperature (primary design parameter) of each of the devices is at a minimum and below the corresponding permissible limit of the device.
2014-04-01
Technical Paper
2014-01-0708
Jugurtha Benouali, Christophe Petitjean, Isabelle Citti, Regis Beauvis, Laurent Delaforge
Abstract The development of Electrical and Hybrid cars led to the introduction of reversible heat pump systems in order to reduce the energy consumption and increase the car autonomy during the Zero Emission Mode. One of the most important components in the heat pump system, is the evaporator condenser that “pumps the heat” from the ambient air. Moreover, this heat exchanger has to work in both modes: A/C (condenser mode) and heat pump (evaporator mode). This paper will explain the main steps of the development of this heat exchanger: circuiting (refrigerant side) in order to improve the homogeneity and the performances fins (air side) in order to reduce icing impact. We will also present system tests results that illustrate the impact of those evolutions on loop performances (heating capacity and COP).
2014-04-01
Technical Paper
2014-01-0698
Xiaojie Lin, Hoseong Lee, Yunho Hwang, Reinhard Radermacher, Jungho Kwon, Chunkyu Kwon
Abstract In this paper, the application of the separate sensible and latent cooling (SSLC) technology to the mobile air conditioning (MAC) system was investigated. Conventional MAC systems utilize a low evaporating temperature to cool down the cabin air temperature and to remove moisture from humid air. In order to remove the moisture, the supply air temperature has to be below the dew point temperature of the cabin air. Therefore, a reheating process is necessary to increase the air temperature to an appropriate and comfortable level. However, energy is wasted in this reheating process, which results in the reduction of the fuel efficiency. Since the SSLC technology can provide an appropriate solution to these issues of conventional systems, it is proposed to apply the SSLC technology to the MAC system, which can eventually reduce the fuel consumption of the MAC system. In the proposed SSLC MAC system, the desiccant wheel is dedicated to handle most of latent load while the vapor compression cycle handles the remaining latent load and sensible load.
2014-04-01
Technical Paper
2014-01-0697
Yinhua Zheng
Abstract This paper addresses various ways to determine vehicle dual AC system charge level. Traditionally, either checking charge level plateau and/or using the certain condenser outlet subcooling magnitude are adopted to determine AC system charge level. It is challenging to determine refrigerant charge level in the following scenarios: (1) Some AC systems do not exhibit the flatted charge plateau. (2) The condenser outlet subcooling continues to rise. (3) The system has the requirements to run both front and aux evaporators, front evaporator only and aux evaporator only. It was found that compressor compression ratio of absolute discharge pressure to absolute suction pressure always presents the bath tub curve for all AC systems. When the system reaches the optimal charge level, the evaporator air outlet temperatures show the stable trend. In addition to the traditional condenser subcooling method, few approaches are presented in the paper. One way to determine the dual evaporator system charge level is: checking compressor compression ratios vs. charge level on the tests with (1) running both front and aux evaporators, (2) running front evaporator only (aux evaporator off).
2014-04-01
Technical Paper
2014-01-0695
Mingyu Wang, Debashis Ghosh, Edward Wolfe, Kuo-huey Chen, Jeffrey Bozeman
Abstract Traditional vehicle air conditioning systems are designed to cool the entire cabin to provide passenger comfort. Localized cooling, on the other hand, focuses on keeping the passenger comfortable by creating a micro climate around the passenger. Such a system also easily adapts to the number of passengers in the car and enables zonal control. The net impact of the localized cooling is that equivalent comfort can be achieved at reduced HVAC energy consumption rate. The present paper reports on a vehicle implementation of localized cooling using Thermoelectric Devices and the resulting energy saving.
2014-04-01
Technical Paper
2014-01-0696
Ruidong Yan, Jun-ye Shi, Han Qing, Jiangping Chen, Ji Song
Abstract Two phase flow mal-distribution in inlet header of the parallel flow evaporator will cause performance degradation, partial frosting and comfortableness problems. In order to solve these issues in heat pump system of electric vehicles, four types of small diameter tube and fin heat exchangers with different flow passage were designed and experimental measured in heat pump system of electric vehicles. The experimental results showed that in terms of performance, the small diameter tube and fin heat exchanger can reach even exceed the micro-channel heat exchanger on capacity and COP in heating model. Compared with micro-channel, the tube and fin heat exchanger with 4 inlets and 4 outlets can increase capacity from 2010W to 2689W, and increase COP from 2.6 to 2.8. However the frost/defrost experimental results showed that there was a decrease on the capacity of micro-channel heat exchanger after several frost/defrost periods. For the small diameter tube and fin heat exchangers, the condensate water was easier to be drained, thus partial pressure difference and heat exchange capacity would recover to the initial value eventually.
2014-04-01
Technical Paper
2014-01-0702
Kamalesh Bhambare, Junya Fukuyama, Jaehoon Han, Kosuke Masuzawa, Akihiro Iwanaga, Steven Patterson
Abstract The climate inside a vehicle cabin is affected by the performance of the vehicle HVAC system, the thermal characteristics of the vehicle structure and the components, as well as the external environmental conditions. Due to the complex interactions among these various factors, the flow field and the temperature distribution can be very complicated. The need for a fully three-dimensional transient analysis is increasing in order to provide sufficiently detailed information that can be used to improve the vehicle design. In this study, a numerical simulation methodology to predict the local climate conditions in a passenger vehicle cabin is presented. The convective heat transfer from both the exterior and the interior of the cabin were calculated by three dimensional CFD simulations using a Lattice-Boltzmann method based flow solver. The conduction and the radiation effects including the solar loading were solved using a finite-difference based radiation-conduction thermal solver.
2014-04-01
Technical Paper
2014-01-0701
Huize Li, Predrag Hrnjak
Abstract The effect of lubricant on distribution is investigated by relating the flow regime in the horizontal inlet header and the corresponding infrared image of the evaporator. Visualization of the flow regime is performed by high-speed camera. R134a is used as the refrigerant with PAG 46 as lubricant, forming foam in all flow regimes. Quantitative information including foam location, foam layer thickness is obtained using a matlab-based video processing program. Oil circulation rate effect on flow regime is analyzed quantitatively.
2014-04-01
Technical Paper
2014-01-0700
Mark Zima, Mingyu Wang, Prasad Kadle, Joe Bona
Abstract Variable displacement compressors have proven to be more energy efficient than the equivalent compressor with fixed displacement for mobile A/C applications. Variable displacement compressors de-stroke rather than cycle to prevent the evaporator from freezing. Cycling an internally controlled variable compressor is counter intuitive, yet results in a 15-20% reduction in the energy used by the compressor as demonstrated by tests on multiple vehicle applications. Externally controlled variable compressors have the highest energy efficiency and extending cycling to these compressors during cool temperatures reduces the compressor energy consumption by 10%.
2014-04-01
Technical Paper
2014-01-0699
Sandip Pawar, Upender Rao Gade, Atish Dixit, Suresh Babu Tadigadapa, Sambhaji Jaybhay
Abstract The objective of the work presented in this paper is to provide an overall CFD evaluation and optimization study of cabin climate control of air-conditioned (AC) city buses. Providing passengers with a comfortable experience is one of the focal point of any bus manufacturer. However, detailed evaluation through testing alone is difficult and not possible during vehicle development. With increasing travel needs and continuous focus on improving passenger experience, CFD supplemented by testing plays an important role in assessing the cabin comfort. The focus of the study is to evaluate the effect of size, shape and number of free-flow and overhead vents on flow distribution inside the cabin. Numerical simulations were carried out using a commercially available CFD code, Fluent®. Realizable k - ε RANS turbulence model was used to model turbulence. Airflow results from numerical simulation were compared with the testing results to evaluate the reliability. Qualitative parameters such as mean Age of Air (AOA), Broadband Noise model, and Human Thermal Comfort Module (PMV/PPD) were used to gain deeper insight into the problem.
2014-04-01
Technical Paper
2014-01-0685
Devin Furse, SeKil Park, Lee Foster, Simon Kim
Abstract An innovative system has been developed to remotely monitor and record customer usage patterns of the Hyundai Genesis HVAC system in real time by smartphone. The data monitored includes dozens of HVAC-related parameters, including driver and passenger set temperature, blower setting, mode and intake position, internal software parameters, etc. This information and understanding of real-world usage of American customers enables design and test engineers to better satisfy customer demands for automatic temperature control performance. This study identifies areas in need of improvement Preliminary findings of this study suggest that auto mode usage is highest in mild temperatures and lowest in hot soaking conditions. In hot soak conditions (above 35C cabin temperature), the majority of American customers manually control the temperature and blower speed.
2014-04-01
Technical Paper
2014-01-0688
Kambiz Jahani, Sajjad Beigmoradi
Abstract Adequate visibility through the automobile windscreen is a critical aspect of driving, most often at very low temperatures when ice tends to be formed on the windscreen. The geometry of the existing defroster system needs to be improved in the vehicles, with the main aim of substantial increase in air mass flow reaching the windscreen through defroster nozzles and appropriate velocity distribution over the windscreen, while respecting all packaging constraints. The reason of this study is to investigate the windscreen deicing behavior of a vehicle by means of Computational Fluid Dynamics (CFD) with the main concern of improving deicing process by design an appropriate defroster. Two different defrosters with completely different geometry are considered for this purpose. A detailed full interior model of an existing vehicle is created via CAE tools. A transient simulation is performed and results are extracted to show how a proper design of the defroster will lead to considerable improve in deicing process.
2014-04-01
Technical Paper
2014-01-0689
Neal Lawrence, Stefan Elbel
Abstract Two-phase ejectors are devices capable of recovering the expansion power that is lost by the throttling process in air conditioning cycles, resulting in improved system performance. High-pressure fluids such as CO2 have received the majority of attention in two-phase ejector studies in recent years due to the fluid's high throttling loss and high potential for improvement. However, low-pressure working fluids such as R134a, commonly used in automotive applications, have received considerably less attention owing to their lower recovery potential. While the two fluids have very different properties, both offer the potential for noticeable COP improvement with ejector cycles. Thus, understanding the operation and performance of ejectors with both fluids can be important to the design of ejector air conditioning cycles. This paper compares available experimental data for the performance of two-phase ejectors using CO2 and R134a. CO2 ejectors are capable of recovering a greater amount of power than R134a due to CO2's larger throttling loss as well as the ability of CO2 ejectors to recover a larger portion of the available power.
2014-04-01
Technical Paper
2014-01-0690
Kevin Cheung, Erich Becker
Abstract Vehicles with a large cabin volume incorporate two HVAC units to provide comfort to the front and rear cabin. Each HVAC unit can generate independent airflow volume, temperature, and airflow direction. A new HVAC unit was developed to achieve the performance and functionality of two HVAC units. A unique HVAC construction was used to achieve independent front and rear airflow volume, temperature, and airflow direction distribution. This integrated front and rear HVAC unit provides additional packaging space for other vehicle components and reduces the overall number of HVAC system components.
2014-04-01
Technical Paper
2014-01-0692
Huize Li, Predrag Hrnjak
Abstract This paper presents an experimental study of lubricant effect on the performance of microchannel evaporators in a typical MAC system. R134a is used as the refrigerant with PAG46 lubricant. The increase of oil circulation rate elevates the pressure drop of the evaporator. The specific enthalpy change in evaporator decreases with increasing oil circulation rate, while refrigerant distribution appears to be more uniform as indicated by infrared images of the evaporator surface temperatures. Thus mass flow rate increases.
2014-04-01
Technical Paper
2014-01-0677
Saiful Bari, Shekh Rubaiyat
Abstract The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power using a separate Rankine Cycle (RC) or an Organic Rankine Cycle (ORC). Water is the best working fluid for this type of applications in terms of efficiency of the RC system, availability and environmental friendliness. However, for small engines and also at part load operations, the exhaust gas temperature is not sufficient enough to heat the steam to be in superheated zone, which after expansion in the turbine needs to be in superheated zone. Ammonia was found to be an alternate working fluid for these types of applications which can run at low exhaust temperatures. Computer simulation was carried out with an optimized heat exchanger to estimate additional power with water and ammonia as the working fluids. ANSYS 14.0 CFX software was used for the simulation. It was found that at full load 23.7% and 10.9% additional power were achieved by using water and ammonia as the working fluids respectively.
2014-04-01
Technical Paper
2014-01-0678
Takatoshi Furukawa, Masaaki Nakamura, Koichi Machida, Kiyohiro Shimokawa
Abstract In heavy duty (HD) trucks cruising on expressway, about 60% of input fuel energy is wasted as losses. So it is important to recover them to improve fuel economy of them. As a waste heat recovery system, a Rankine cycle generating system was selected. And this paper mainly reports it. In this study, engine coolant was determined as main heat source, which collected energies of an engine cooling, an EGR gas and an exhaust gas, for collecting stable energy as much as possible. And the exergy of heat source was raised by increase coolant temperature to 105 deg C. As for improving the system efficiency, saturation temperature difference was expanded by improving performance of heat exchanger and by using high pressure turbine. And a recuperator which exchanges heat in working fluid between expander outlet and evaporator inlet was installed to recover the heat of working fluid at turbine generator. Then a working fluid pump was improved to reduce power consumption of the system. And Hydro-fluoro-ether was selected as suitable working fluid for the system for vehicles.
2014-04-01
Technical Paper
2014-01-0681
Shivakumar Banakar, Dirk Limperich, Ramesh Asapu, Vaishnavi Panneerselvam, Madhu Singh
Abstract Air-cooled fin and tube heat exchangers are used as a condenser in the conventional automotive Heating Ventilation & Air-Conditioning (HVAC) systems. In this study, the use of liquid cooled plate heat exchanger as a condenser in the automotive HVAC systems has been investigated. In the proposed configuration, the cabin heat absorbed by the refrigerant in HVAC system is rejected to the coolant through a liquid cooled condenser and then to the ambient air through a low temperature radiator. Hence, the proposed configuration combines heat rejection from HVAC system with a low temperature radiator circuit of power train cooling. Mixture of Ethylene glycol & Water (coolant), which is used in power train cooling system, is used as secondary fluid in the condenser. Primarily, work done involves design of a liquid cooled condenser, determining boundary conditions for the coolant circuit and evaluation of overall performance of the refrigeration cycle in the HVAC system at various operating conditions.
2014-04-01
Technical Paper
2014-01-0682
Pengyi Cui, Bin Xu
Abstract Air purifier has been prevalently used in the passenger vehicle cabins to reduce in-cabin UltraFine Particle (UFP) concentration. In this study, Computational Fluid Dynamics (CFD) was applied to simulate the in-cabin UFP transport and distribution under different ventilation modes with different characteristics of the air purifier. Ventilation settings, air purifier settings, and air purifier location were identified as the important factors determining the in-cabin UFP distribution and transport. Downward ventilation airflow direction and smaller ventilation air velocity can be considered by the drivers for a lower in-cabin UFP concentration. Upward airflow direction from the air purifier's inlet and larger air velocity were recommended since it led up to 50% in-cabin UFP reduction. Air purifier installed at middle ceiling of the cabin develops the most efficient airflow for UFP removal. Explicit relationships between in-cabin UFP distribution and the air purifier settings were presented as a reference to facilitate cabin air purifier design for more efficient in-cabin UFP removal.
2014-04-01
Technical Paper
2014-01-0684
B. Vasanth, Jose Bright, Pavan Reddy, Sathish Kumar S, Murali Govindarajalu
Abstract In an Automotive air conditioning system, the air flow distribution in the cabin from the HVAC (Heating, ventilation and air conditioning), ducts and outlets is evaluated by the velocity achieved at driver and passenger mannequin aim points. Multiple simulation iterations are being carried out before finalizing the design of HVAC panel duct and outlets until the target velocity is achieved. In this paper, a parametric modeling of the HVAC outlet is done which includes primary and secondary vane creation using CATIA. Java macro files are created for simulation runs in STAR CCM+. ISIGHT is used as an interface tool between CATIA and STARCCM+. The vane limits of outlet and the target velocity to be achieved at mannequin aim points are defined as the boundary conditions for the analysis. Based on the optimization technique and the number of iterations defined in ISIGHT, the vane angle model gets updated automatically in CATIA followed by the simulation runs in STARCCM+. Based on the results vane angle will get updated and the iterations continues automatically till the target velocity is met at the aim points.
2014-04-01
Technical Paper
2014-01-0680
Jason Aaron Lustbader, Cory Kreutzer, Matthew A. Jeffers, Steven Adelman, Skip Yeakel, Philip Brontz, Kurt Olson, James Ohlinger
Abstract Cab climate conditioning is one of the primary reasons for operating the main engine in a long-haul truck during driver rest periods. In the United States, sleeper cab trucks use approximately 667 million gallons of fuel annually for rest period idling. The U.S. Department of Energy's National Renewable Energy Laboratory's (NREL) CoolCab Project works closely with industry to design efficient thermal management systems for long-haul trucks that minimize engine idling and fuel use while maintaining occupant comfort. Heat transfer to the vehicle interior from opaque exterior surfaces is one of the major heat pathways that contribute to air conditioning loads during long-haul truck daytime rest period idling. To quantify the impact of paint color and the opportunity for advanced paints, NREL collaborated with Volvo Group North America, PPG Industries, and Dometic Environmental Corporation. Initial screening simulations using CoolCalc, NREL's rapid HVAC load estimation tool, showed promising air-conditioning load reductions due to paint color selection.
2014-04-01
Technical Paper
2014-01-0671
Can Yang, Hui Xie, Shengkai Zhou
Abstract The RCS (Rankine cycle system) used to recover the exhaust gas energy from internal combustion engines has been regarded as one of the most promising ways to achieve higher efficiency. However, it is a big challenge to keep the RCS still in good performance under variable driving cycle. This paper aims at revealing the reasons resulting in the low efficiency under driving cycle, comparing to that under steady-state condition. The dynamic operating process of the RCS under driving cycle is analyzed, and then the RCS applied on an 11.6L heavy duty diesel engine is modeled. Based on that, the dynamic performance of the RCS under an actual driving cycle is discussed. The results indicate that the average efficiency under a piece of Tianjin bus driving cycle is as low as 3.63%, which is less than half of that (7.77%) under the rated point (1300rpm and 50%load). The reasons leading to the low efficiency under driving cycle is interpreted from three aspects. Firstly, effects of the optimizing criterions are studied.
2014-04-01
Technical Paper
2014-01-0668
Armin Traussnig, Heinz Petutschnig, Andreas Ennemoser, Michael Stolz, Mauro Tizianel
Abstract In order to meet current and future emission and CO2 targets, an efficient vehicle thermal management system is one of the key factors in conventional as well as in electrified powertrains. Furthermore the increasing number of vehicle configurations leads to a high variability and degrees of freedom in possible system designs and the control thereof, which can only be handled by a comprehensive tool chain of vehicle system simulation and a generic control system architecture. The required model must comprise all relevant systems of the vehicle (control functionality, cooling system, lubrication system, engine, drive train, HV components etc.). For proper prediction with respect to energy consumption all interactions and interdependencies of those systems have to be taken into consideration, i.e. all energy fluxes (mechanical, hydraulically, electrical, thermal) have to be exchanged among the system boundaries accordingly. However, it is very important that the level of detail of the VTMS model fits to the current phase of the vehicle development process.
2014-04-01
Technical Paper
2014-01-0670
Chengyu Zhang, Ge-Qun Shu, Hua Tian, Haiqiao Wei, Guopeng Yu, Youcai Liang
Abstract This paper presents a model system TEG-DORC that employs thermoelectric generator (TEG) as a topping cycle integrated with a dual-loop organic Rankine bottoming cycle (DORC) to recover exhaust heat of internal combustion engine (ICE). The thermodynamic performance of TEG-DORC system is analyzed based on the first and second law of thermodynamics when system net output power Wnet, thermal efficiency ηth, exergy efficiency ηe and volumetric expansion ratio are chosen as objective functions. The model has many parameters that affect combined system performance such as TEG scale, evaporation pressure of high temperature ORC loop (HT loop) Pevp,HT, condensation temperature of HT loop Tcond,HT. It is suggested that HT loop has a vital influence on system performance. The results show that TEG-DORC system can significantly improve system performance, and system net output power gets maximum (30.69kW) when Tcond,HT is 370K and Pevp,HT is 4MPa, accordingly, the absolute effective thermal efficiency increases by 5.2%.
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