scholarly journals Coupling Effect of Air Flow Rate and Operating Conditions on the Performance of Electric Vehicle R744 Air Conditioning System

2021 ◽  
Vol 11 (11) ◽  
pp. 4855
Author(s):  
Anci Wang ◽  
Jianmin Fang ◽  
Xiang Yin ◽  
Yulong Song ◽  
Feng Cao ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Flow Rate ◽  
Air Conditioning ◽  
Volume Flow Rate ◽  
Air Flow ◽  
Volume Flow ◽  
Air Flow Rate ◽  
Air Volume ◽  
Discharge Pressure ◽  
Air Conditioning Systems

The air flow rate on the gas cooler side is one of the key parameters affecting the performance and running safety of transcritical CO2 electric vehicle air conditioning systems. After experimentally analyzing the effects of the air volume flow rate in the gas cooler on the cycle parameters and system performance, a novel method to evaluate the optimal air flow rate was proposed. In addition, the effect of the gas cooler air volume flow rate on the key performance parameters of the system (e.g., optimal discharge pressure) was explored. Finally, the coupling effects of the compressor speed, ambient temperature and optimal air flow rate on the system performance was also exhaustively assessed. It was found that as the discharge temperature, the CO2 temperature at the gas cooler outlet and the discharge pressure did not vary more than ±2%, the corresponding gas cooler air volume flow rate was optimal. For the single-row and dual-process microchannel evaporator used in this work, the recommended value of the optimal gas cooler air volume flow rate was 2500 m3·h−1. The results could provide reference for the fan speed design of electric vehicle CO2 air conditioning systems, especially for the performance under idling model.

Numerical Simulation on Air Volume Flow Rate Distribution of Stator Ducts for Salient Pole Synchronous Motor

2014 ◽  
Vol 644-650 ◽  
pp. 373-376
Author(s):  
Li Liu ◽  
Yi Ping Lu ◽  
Jia De Han ◽  
Xue Mei Sun
Keyword(s):  
Flow Rate ◽  
Volume Flow Rate ◽  
Domain Boundary ◽  
Air Flow ◽  
Flow Characteristics ◽  
Synchronous Motor ◽  
Volume Flow ◽  
Rate Distribution ◽  
Salient Pole ◽  
Air Volume

Air volume flow rate distribution of stator ducts along axial and circumferential for salient pole synchronous motor is strongly influenced by the air flow field in the air gap and rotor poles, which is completely different from the flow characteristics of non-salient pole motor and it directly relates to the peak temperature of stator bars and core and axial temperature difference which can affect the safety of the operation. A three-dimensional physical model of 1/8 motor was established and corresponding solution domain boundary conditions were given in this article. The air volume flow rate distribution of stator ducts along axial and circumferential was analyzed based on CFD. The study show that at the same position of the axial stator, the cooling air flow into stator ducts along the circumferential direction is uneven, the air volume flow rate distribution is largely influenced by rotor pole pieces, geometry and position of pole support block and rotor rotation direction.

scholarly journals Minimization of fan energy consumption in ventilation and (or) air-conditioning systems as an optimization calculus of variations

2019 ◽  
Vol 116 ◽  
pp. 00033
Author(s):  
Michał Karpuk
Keyword(s):  
Energy Consumption ◽  
Calculus Of Variations ◽  
Flow Rate ◽  
Air Conditioning ◽  
Air Flow ◽  
Rate Function ◽  
Hazardous Substances ◽  
Air Flow Rate ◽  
Starting Conditions ◽  
Air Conditioning Systems

The article presents an optimization calculus of variations of fan energy consumption in ventilation and (or) air-conditioning systems. It defines an air flow rate function that depends on the time of operation in the defined room size, starting conditions and the function of hazardous substances emission rate in the room. The differential form of air flow rate dependence on density of hazardous substances allows to establish a connection between air pollution in the room and a fan air flow rate, i.e. fan energy consumption. Creating a fan energy model experiment in the room in different conditions allows to minimize energy consumption to 5–30% depending on existing conditions.

scholarly journals A Novel Non-Intrusive Vibration Energy Harvesting Method for Air Conditioning Compressor Unit

2021 ◽  
Vol 13 (18) ◽  
pp. 10300
Author(s):  
Chuan Choong Yang ◽  
Noor Fiqri Razqi Bin Noor Hanafi ◽  
Noor Hazrin Hany Bt Mohamad Hanif ◽  
Ahmad Faris Ismail ◽  
Hsueh-Hsien Chang
Keyword(s):  
Flow Rate ◽  
Air Conditioning ◽  
Volume Flow Rate ◽  
Piezoelectric Sensor ◽  
Volume Flow ◽  
Vibration Energy ◽  
Compressor Unit ◽  
Flow Rates ◽  
Air Volume ◽  
Custom Made

The purpose of harvesting vibration energy is to obtain clean and sustainable energy by converting vibration energy from ambient sources into a voltage output. In this work, a piezoelectric sensor, PZT-5H is attached to a 3D printed and custom-made mounting to be placed at an air conditioning condenser unit, to harvest vibration energy. The configuration of the harvester is non-intrusive, in which the harvester did not intrude into compressor unit operation. Temperature (20 °C, 22 °C, and 24 °C) and air volume flow rates (3 levels of air volume flow rate at 245 L/second, 274 L/second, and 297 L/second) were taken into consideration in this investigation. An accelerometer was first used to investigate the optimum vibration frequency in Hertz, and six locations were identified. Next, the piezoelectric sensor was mounted at these six locations, and the output root-mean-square (RMS) voltage from the piezoelectric sensor was obtained. The analysis of variance (ANOVA) indicated that temperature and air volume flow rates factors were significant. It was found that the location identified with the highest amount of vibration at 830.2 Hz from accelerometer measurement, was also the highest amount of RMS voltage, at 510.82 mV, harvested by the piezoelectric, from the temperature of 20 °C and air volume flow rates at high level (air flow volume flow rate at 297 L/second). From this work, it is feasible to utilize this novel method of harvesting waste vibration energy from the air conditioning compressor unit.

Online Optimal Ventilation Control of Building Air-conditioning Systems

2010 ◽  
Vol 20 (1) ◽  
pp. 129-136 ◽  
Author(s):  
Shengwei Wang ◽  
Zhongwei Sun ◽  
Yongjun Sun ◽  
Na Zhu
Keyword(s):  
Energy Consumption ◽  
Flow Rate ◽  
Control Strategy ◽  
Air Conditioning ◽  
Air Flow ◽  
Air Flow Rate ◽  
Ventilation Control ◽  
Occupancy Detection ◽  
Critical Zones ◽  
Air Conditioning Systems

This paper presents a ventilation control strategy for multi-zone variable air volume (VAV) air-conditioning systems; integrating the sequential split-range control strategy for air-handing units with an aim to optimise the fresh air flow rate by compromising the indoor air quality and energy consumption. In this strategy, a CO2 -based adaptive demand-controlled ventilation scheme would employ a dynamic multi-zone ventilation equation for multi-zone air-conditioning systems, in which a CO2-based dynamic occupancy detection scheme would be used for online occupancy detection. The strategy would identify the critical zones online, and fully consider the outdoor air demand of critical zones, while, a model-based fresh air flow rate optimal control scheme is employed for VAV air-conditioning systems with the primary air handling units. An adaptive optimisation algorithm would be used for optimising the fresh air flow rate to minimise the energy consumption. The energy saving potentials in the Hong Kong climate condition by optimising fresh air ventilation and the practical implementation of the control strategy are also discussed in this paper.

scholarly journals Heating Performance Characteristics of an Electric Vehicle Heat Pump Air Conditioning System Based on Exergy Analysis

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2868 ◽  
Author(s):  
Xingwang Tang ◽  
Qin Guo ◽  
Ming Li ◽  
Mingzhe Jiang
Keyword(s):  
Ambient Temperature ◽  
Electric Vehicle ◽  
Flow Rate ◽  
Air Conditioning ◽  
Air Flow ◽  
Exergy Destruction ◽  
Air Flow Rate ◽  
Air Conditioning System ◽  
Heating Capacity ◽  
Expansion Valve

In this paper, a heat pump air conditioning system (HPACS) with refrigerant R134a based on the functional requirements of battery electric vehicle is designed and tested. Experiments were conducted to evaluate the effects of different ambient temperature, air flow rate of internal condenser, expansion valve (EXV) opening and compressor speed. The results demonstrate that air flow rate of internal condenser, EXV opening and compressor speed have important impact on heating capacity, compressor power consumption and coefficient of performance (COP) under several ambient temperatures. To verify the HPACS can also provide the heating capacity required by the battery electric vehicle cabin in cold climate, the system was also tested under a −5 °C ambient temperature, it was found that the heating capacity is 3.6 kW and the COP is 3.2, demonstrating that the system has high energy efficiency. In addition, heating process analysis of the HPACS under lower temperature is studied by exergy principle. The results indicate that compressor is the highest exergy destruction in all components, accounting for 55%. The percentage of exergy destruction in other components is about 28%, 12% and 5% for the expansive valve, condenser, and evaporator. Furthermore, air flow rate of internal condenser, ambient temperature and expansion valve opening have important impact on exergy destruction and exergy efficiency of the HPACS.

scholarly journals Automobile Radiator’s Engineering and Analysation

2020 ◽  
Vol 9 (5) ◽  
pp. 554-558
Keyword(s):  
Flow Rate ◽  
Heat Dissipation ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Air Flow ◽  
Temperature Drop ◽  
Inlet Temperature ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Cooling Fan

The shape of a radiator cover is crucial either in determining the pattern of air flow or in increasing the same through the radiator core thereby increasing the thermal efficiency, thus making it a necessity to understand it. Moreover the parts circumjacent to the core namely the upper tank, lower tank, cooling fan, fins, tubes, etc promote the air flow rate. Also it is to note that the air flow rate of discharge gases from radiator core is one of the prime factors in determining the automobile cooling system. Initially factors such as temperature, pressure, air flow rate that affect the performance are obtained in order to derive out the entities of operation. One of the observations that can be made through this paper is that as the volume of the coolant increases, the rate of heat dissipation increases, also parameters like inlet temperature and volume flow rate of coolant, air velocity, temperature drop and drop in pressure of coolant are factors that contribute in radiator performance evidently.

Numerical and experimental investigation on the air flow characteristics of heating, ventilation, and air-conditioning module for a small electric vehicle

2019 ◽  
Vol 234 (6) ◽  
pp. 1597-1609
Author(s):  
Kang Li ◽  
Hao Gao ◽  
Peng Jia ◽  
Lin Su ◽  
Yidong Fang ◽  
...  
Keyword(s):  
Heat Pump ◽  
Flow Rate ◽  
Air Conditioning ◽  
Air Flow ◽  
Flow Characteristics ◽  
Cold Climate ◽  
Airflow Rate ◽  
Positive Temperature ◽  
Air Flow Rate ◽  
Pump System

In electrical vehicles, replacing positive temperature coefficient heater as heat source with an air source heat pump could improve the driving range and decrease energy consumption in cold climate. Design of the heating, ventilation, and air-conditioning module for heat pump system has a significant influence on its performance in each working mode. A newly designed heat pump heating, ventilation, and air-conditioning module was introduced in this paper. The air flow characteristics of the heat pump heating, ventilation, and air-conditioning module in four working modes were analyzed, and the air flow rate and wind resistance were obtained by numerical simulation. Experiments were also conducted for validating its airflow rate in each working mode. Results of these experiments show that some unfavorable phenomena such as flow maldistribution and vortex inside the heat pump heating, ventilation, and air-conditioning module exist, which could lead to insufficient utilization of the heat exchange area of heat exchangers and the generation of aerodynamic noise. Furthermore, the air flow rate of the original heating, ventilation, and air-conditioning module was also measured for comparison, and the designed heat pump heating, ventilation, and air-conditioning module shows nearly 15–20% decrease in each working mode.

scholarly journals Numerical Analysis of the Energy Consumption of Ventilation Processes in the School Swimming Pool

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1023
Author(s):  
Piotr Ciuman ◽  
Jan Kaczmarczyk
Keyword(s):  
Energy Consumption ◽  
Flow Rate ◽  
Energy Demand ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Swimming Pool ◽  
Specific Humidity ◽  
Total Energy Consumption ◽  
Air Volume ◽  
Indoor Swimming Pool

Ventilation of an indoor swimming pool is a very energy consuming process. This is a result of, among other things the required high value of the ventilation air volume flow rate, calculated on the basis of the moisture gains in the facility. The total energy consumption consists of the heat required to heat this air and the electricity needed to transport it. It is possible to reduce the ventilation air volume flow rate by assuming the correct value of specific humidity of the supply and indoor air, but then a deterioration of thermal-moisture conditions in the building can be expected. The aim of this paper was to examine how the reduction of the supply air volume flow rate affects the energy consumption for indoor swimming pool ventilation. It was also checked how this consumption can be reduced by using two-stage heat recovery in the air handling unit. Multi-variant simulations of energy consumption for indoor swimming pool ventilation were carried out using the IDA ICE software for day and night operation of the swimming pool throughout the year. The results of the research proved that reduction of the supply air volume flow rate resulted in the lower energy expenditure on ventilation. The variant with additional local air supply to the lifeguard zone was also analysed, which caused only a slight increase in energy demand for ventilation.

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