scholarly journals High-Efficiency HVAC System with Defog/Dehumidification Function for Electric Vehicles

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 46
Author(s):  
Tong-Bou Chang ◽  
Jer-Jia Sheu ◽  
Jhong-Wei Huang
Keyword(s):  
Electric Vehicles ◽  
Air Conditioning ◽  
High Efficiency ◽  
Test Chamber ◽  
Power Saving ◽  
Electric Heating ◽  
Heating System ◽  
Cold Weather ◽  
Hvac System ◽  
Vehicle Interior

Electric vehicles (EVs) generally use an electric heating system to provide heat. However, the heating system consumes a large amount of energy, and therefore reduces the mileage of the vehicle. The energy consumption can be reduced by replacing the electric heating system with a heat pump air conditioning system. Such systems achieve an effective heating of the vehicle interior, but do not provide a defog or dehumidification function. Consequently, the inside surface of the windshield tends to fog in cold weather; leading to poor driver visibility and an impaired road safety. Accordingly, the present study proposes a novel high-efficiency heating, ventilation and air conditioning (HVAC) system with both heating and defog/dehumidification functions for electric vehicles. The effectiveness of the proposed system is investigated experimentally using a simulated cabin placed in a temperature and humidity-controlled test chamber. The experimental results confirm that the HVAC system achieves the required cooling, heating and defog/dehumidification functions and meets the corresponding standards. Moreover, the application of HVAC in EVs could lead to significant electrical power saving effect.

A Study on the Performance of Drinking Fountain Using CO2 Heat Pump under Different System Pressures

2010 ◽  
Vol 44-47 ◽  
pp. 2433-2437 ◽  
Author(s):  
Yu Lieh Wu ◽  
Yu Dai Shiue ◽  
Kuo Hsiang Chien ◽  
Chiu Li Wang
Keyword(s):  
Carbon Dioxide ◽  
Heat Source ◽  
Heat Pump ◽  
Air Conditioning ◽  
High Performance ◽  
High Efficiency ◽  
Electric Heating ◽  
Alternative Refrigerant ◽  
Saving Effect ◽  
Natural Refrigerant

To avoid continuous damage of ozone layer and deterioration of global warming, many countries have devoted to the development and application of natural refrigerant. Although CO2, an alternative refrigerant in the area of air conditioning is not the best all-temperature refrigerant, it has the lowest operating risk as compared to hydrocarbon (HCs) and ammonia.Traditional drinking fountain provides heat source through secondary energy source - electric heating; however, the heating effect is limited. Since heat pump has a high performance, this study used a carbon dioxide heat pump, which has energy-saving effect and high efficiency, to provide heat source to drinking fountains. It further assembled the drinking fountain system with carbon dioxide heat pump and analyzed its performance.

THE PERFORMANCE OF CONDENSER UNDER DIFFERENT VEHICLE SPEEDS

2013 ◽  
Vol 21 (02) ◽  
pp. 1350013 ◽  
Author(s):  
CHIH-CHIU SHEN ◽  
JAU-HUAI LU
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Air Conditioning ◽  
High Efficiency ◽  
Cooling Capacity ◽  
Vehicle Speed ◽  
Air Conditioner ◽  
Electric Motors ◽  
No Emission ◽  
Air Conditioning System

Due to the concern in energy shortage and environmental protection, electric vehicle is considered to be a substitute for the conventional gasoline-powered vehicles due to its characteristics of high efficiency and no emission. However, the load of air conditioning causes a serious problem for electric vehicles, especially in tropical and subtropical areas. The compressor of conventional air conditioning system is driven by engine and its speed is thus coupled to vehicle speed. In electric vehicles, the compressor is driven by electric motors and compressor speed could be decoupled to vehicle speed. This mechanism provides an opportunity to improve the energy efficiency of electric vehicle since the operation of air conditioning system may be independent of vehicle speed. The purpose of this paper is to find out the electric fan operation model as vehicle speed is varied. This paper was to establish a theoretical model for the condenser of automotive air conditioner and to conduct simulation to evaluate the effect of vehicle speed on the cooling capacity and sub-cooling of condenser. Results of simulation demonstrated that vehicle with 6 km h-1 speed has the 5°C of sub-cooling at 0.0266 kg s-1 of refrigerant flow rate and the cooling capacity was 4.93 kW. In this study, an increase of 16.6% in cooling capacity can be reached as the speed of vehicle was raised from 6 to 110 km h-1 and can promote the sub-cooling to 19.5°C. It was also found that the cooling capacity of air conditioner is extremely sensitive to vehicle speed while the vehicle is running at low speed. Furthermore, increases in the vehicle speed resulted in reduction of the length of superheat region from 17.5 to 8.5 cm. Finally, a correlation among these variables and the simulated cooling capacity was obtained in this study, enabling the relevant researchers to evaluate automotive air conditioner performance under different vehicle speeds more easily.

PV Operated HVAC for Southwest States

Solar Energy ◽  
2006 ◽  
Author(s):  
Joseph McCabe
Keyword(s):  
Direct Current ◽  
Air Conditioning ◽  
High Efficiency ◽  
Air Conditioner ◽  
Hvac System ◽  
Energy Usage ◽  
Pv System ◽  
Two Stage ◽  
System A ◽  
Evaporative Cooler

This report analyzes energy usage and associated utility capacity requirements for compressor based air-conditioning compared to evaporative cooling supplied by electricity from photovoltaics (PV). Two novel scenarios are presented, two stage evaporative coolers with grid tied PV, and two stage evaporated coolers supplied with direct current (DC) electricity from PV. The two scenarios are complimentary; where a grid tied system can tap DC for air-conditioning purposes (see Figure 1). 8% PV system gains can be achieved by eliminating the inverter for powering such a DC heating, ventilating and air-conditioning (HVAC) system. A PV system directly coupled to high efficiency evaporative cooler can remove the air-conditioner peak demand from a utilities load profile. Typical cities energy comparisons are presented. Incentive and public goods programs are not necessarily designed for this optimized, direct utilization of DC approach.

COOLING FLOOR AC SYSTEMS

2005 ◽  
Vol 19 (01n03) ◽  
pp. 511-516
Author(s):  
LU JUN ◽  
DING HAO ◽  
ZHANG HONG ◽  
GAO DIAN CE
Keyword(s):  
High Efficiency ◽  
Residential Buildings ◽  
Residential Building ◽  
Heating System ◽  
High Energy ◽  
Hot Water ◽  
Hvac System ◽  
Winter Climate ◽  
Air Supply ◽  
Energy Consuming

The present HVAC equipments for the residential buildings in the Hot-summer-and-Cold-winter climate region are still at a high energy consuming level. So that the high efficiency HVAC system is an urgently need for achieving the preset government energy saving goal. With its advantage of highly sanitary, highly comfortable and uniform of temperature field, the hot-water resource floor radiation heating system has been widely accepted. This paper has put forward a new way in air-conditioning, which combines the fresh-air supply unit and such floor radiation system for the dehumidification and cooling in summer or heating in winter. By analyze its advantages and limitations, we found that this so called Cooling/ Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. We also recommend a methodology for the HVAC system designing, which will ensure the reduction of energy cost of users.

scholarly journals Efficiency of electric vehicle interior heating systems at low ambient temperatures

2021 ◽  
Vol 11 (1) ◽  
pp. 499-507
Author(s):  
Maciej Gis ◽  
Piotr Wiśniowski ◽  
Mateusz Bednarski
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Heating System ◽  
Electric Heater ◽  
The European Union ◽  
Vehicle Interior ◽  
Ambient Temperatures ◽  
Electric Car ◽  
Car Market ◽  
The Moment

Abstract The electric car market is becoming more and more extensive. According to ACEA, in 2019, 549,387 full electric passenger vehicles, hybrid plug-ins and hydrogen vehicles were registered in the European Union. Thus, it is an increase of 52.9 percent compared to 2018. Germany is the leader with 108 839 registrations of vehicles (+60.9% y/y). Great Britain achieved an increase of 21.5 percent y/y and the number of registrations at 72 834 pieces. The Netherlands came next (66 957 pcs, + 146.3% y/y), France (61 356 pcs, +34.6% y/y) and Sweden (40 406 pcs, + 39.4% y/y). Registration results in Europe shows that the popularity of electric vehicles is increasing. Along with the development of this type of vehicles, the technology used in their construction also changes. The biggest calls at the moment are batteries for these vehicles, as well as their ranges on a single charge. There are already vehicles with ranges of 500 km or even 600 km. However, it turns out that these are not the only problems with electric vehicles One of the drawbacks is the way they heat their passenger cabins. There is no typical heater in an electric vehicle as in the case of a vehicle with a conventional drive. For this purpose, e.g. an electric heater with a blower is used for this purpose. For this reason, the authors of the paper decided to determine the efficiency of the heating system in an electric vehicle at low ambient temperatures. Own tests were carried out on the vehicle at temperatures of +5°C, −5°C and −10°C. Based on the research, the authors of the paper could draw conclusions on how to heat the interior in the electric vehicle under test, as well as check whether the efficiency of such a system for individual places in the car is sufficient to obtain the set temperature.

The Heating System of Agricultural Facilities Using Excess Heat Power Transformers

2020 ◽  
Vol 67 (1) ◽  
pp. 42-47
Author(s):  
Anatoliy I. Sopov ◽  
Aleksandr V. Vinogradov
Keyword(s):  
System Design ◽  
Heat Supply ◽  
Cooling System ◽  
Power Transformer ◽  
Electric Heating ◽  
Heating System ◽  
Power Transformers ◽  
Large Power ◽  
Excess Heat ◽  
Power Centers

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.

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