Browse Topic: Heating, ventilation, and air conditioning systems (HVAC)

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A Novel Approach to Make an Efficient Thermal Management of a Solar Electric Four-Wheeler Through Model-Based System Simulation2024-26-013001/16/2024
The objective of this paper is to determine and design an optimized thermal management system for a solar electric four-wheeler while considering system influence. The major systems that will be analyzed and optimized include the HVAC, solar system, and battery. The HVAC system imposes a challenge to the designers to fulfill the passenger's comfort and to operate it efficiently under a wide range of external loads from solar radiation, ambient temperature & humidity, human metabolic activity, and also other loads like the propulsion system temperature on the cabin. From the literature, it is found that the air conditioning system reduces on average 14% of the total battery capacity whereas the heating system reduces it by 18%, which makes the HVAC system design a crucial aspect to consider for the system influence. The battery car voltage changes significantly to meet the power demand and because of this, the battery system produces a large amount of heat while discharging which will
Karthikeyan, Vikram Raj, Gumma, Muralidhar
Improving Dynamic Response of PEMFC Anode Pressure in Droped Load Scenarios through Split Range Control2023-01-702610/30/2023
The dynamic response of proton exchange membrane (PEM) fuel cells’ anode pressure and the pressure difference between the cathode and anode significantly influence the performance and durability of fuel cells. To address the slow dynamic response of the anode pressure during rapid load drops, this study proposes a split range control strategy by introducing the hydrogen purge valve into the anode pressure control. By rational planning the split range block, the hydrogen purge valve is opened at appropriate times during load drops. To validate the effectiveness of the split range control, simulations are conducted under load drop conditions using an 80 kW fuel cell hydrogen and air supply subsystem model. The simulation results demonstrate that the split range control reduces the setting time of the anode pressure during load drops by half, with the most significant improvement observed at 67% load to idle condition, where the setting time is reduced from 2.6 s to 1.1 s. Furthermore
Zhang, Junyu, Chen, Fengxiang, Pei, Fenglai, Li, Tao, Xu, Shuo
Feasibility of In situ vehicle level transmission loss measurement to guide dash pass through grommet selections2025-01-012205/05/2023
Noise transmission through the vehicle dash panel plays a critical role in isolating passengers from noise sources within the motor bay of the vehicle. Grommets containing electrical harness routing as well as HVAC lines are examples of dash panel pass throughs that should be selected with care. Acoustic performance of these components is generally characterized in terms of measured quantities such as noise reduction (NR), sound transmission loss (STL), and Insertion Loss (IL). These measurements need to be carried out as per SAE or ASTM standards in appropriate anechoic or reverberant chambers as this is important for consistency. This work explores an in-situ vehicle measurement setup utilizing a repurposed vehicle cabin designed to serve as an anechoic chamber with its frunk acting as a reverberant chamber. This in-situ setup method is then compared to results following standards to discuss the differences in results. The data is studied to understand if there are any advantages to
Joodi, Benjamin, Jayakumar, Vignesh, Chang, Michael, Geissler, Christian, Pilz, Fernando, Conklin, Chris
Tonal noise investigation of automotive HVAC systems : a hybrid method2025-01-002705/05/2023
There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the foreground of noise emissions. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low frequency tone noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the mechanism of
Bennouna, Saad, Alaoui, Mohamed
Research on NVH Performance of Pulse Heating System of One Vehicle2025-01-007805/05/2023
When the ambient temperature is too low, the performance of the lithium-ion battery will deteriorate, and the car will have the problems of difficult charging, fast power consumption, and even difficult to start, so the battery needs to be heated before use to provide a comfortable working environment for the lithium-ion. The high-frequency pulse heating system can quickly and evenly raise the temperature of the battery, but there is noise during operation, which affects the NVH performance of the vehicle itself, and its noise comfort needs to be further optimized. Firstly, the high-frequency pulse heating system is discussed in detail, and the parameters affecting NVH performance and heating efficiency are explored. Secondly, NVH testing and subjective and objective evaluation were carried out based on different system parameters, relevant data were collected to establish a model, the influence of each parameter on the two was demonstrated, multi-objective optimization was carried out
YUN, ZHAO, Shouhui, Huang, zhou, changshui, Teng, Charlie
Application of Packing in Sealing Doors and Reducing Fluid Leakage in Automotive HVAC of Climate Control System.2022-28-045711/09/2022
The heating, ventilation and air conditioning system is one of the complex system install inside the cabin of automobile vehicle. Each HVAC discipline has specific design requirement in terms of packaging space, performance target etc. Technical specification such as airflow, noise, air distribution, allowable leakage rate varies as per vehicle segment and interior design accordingly. While maintaining the design parameter of HVAC, design engineers often faces challenges related to water leakage, air leakage, water infiltration etc. Controlling these parameters becomes crucial for customer satisfaction and for safety features. Several researches on seal proof technology is done and still going on, either for air based application or water based application or any other fluid material. Application of sealing technology spread over almost everywhere from domestic purpose to industrial application. Similarly in HVAC, application of packing for sealing doors or reducing leakage plays a
raj, Abhishek, Bajpai, Himanshu, Agarwal, Roopak
Developing Intelligent Windshield Fogging Prediction and HVAC Control Model2022-28-046011/09/2022
The Indian continental region encompasses various geographical terrains and climatic conditions, which summons the automotive OEMs to build a robust Heating Ventilation Air Conditioning (HVAC) system. For a typical passenger cars and utility vehicle segments, on board HVAC primarily serves two major purpose a) providing year round thermal comfort to the passengers and b) enact defogging and defrosting action of front windshield as per regulatory requirement and customer need. Nowadays, Full Automatic Temperature Control (FATC) is introduce in nearly all segments of passenger cars. It intelligently manages HVAC system as per customer comfort. Although case of windshield fogging which deteriorates front vision through windshield is not fully automatize and actively manage. The case of repetitive unclear front vision severely affects driving safety for the occupants. Thus, customer as per their observation of fogging over windshield will manually activate/deactivate defog mode. The
Venu, Santosh, Mehta, Bhavik, Panchare, Datta
AC System COP Optimization Through Major or Minor Adjustment of Component Design2022-28-042311/09/2022
In the process of designing of complete cycle of vapour compression refrigerant system, most important part is optimization of performance of all components including compressor, condenser, expansion valve, evaporator and piping and COP of the system . For balancing and COP optimization of air conditioning cycle, it is extremely important that all component selected must be balanced and synchronized with other components relatively. Many researches have been done related to system COP and performance optimization through various method as well as component performance optimization. While optimizing the cycle, changing one component parameter effects the other components behavior and becomes challenge to control all other characteristic. Sometimes even a minor adjustment in the cycle leads change in output result of components which are not preferable. The present paper is about optimization of system COP of refrigerant cycle through various combination of iteration that includes
raj, Abhishek, Bajpai, Himanshu, Agarwal, Roopak, Anal, Rajeev
Improve the Passenger Thermal Comfort Inside Car Cabin at Various Seat Location2022-28-044511/09/2022
In today’s competitive automotive industry with its rapid pace of innovation, HVAC engineers continually think about customer convenience and their comfort requirements. ‘Multi zone HVAC system’ is one of the features that proposes to satisfy the customers’ need for individualized comfort settings for each passenger seated in different parts of a vehicle cabin. In many instances, passengers in a car have different preferences for air temperature setting based on their sitting locations. This situation sometimes arises due to difference in the intensity of solar radiation entering inside vehicle cabin from windscreen and front/side glasses. This happens due to relative position of the sun and the direction which the car is facing. In the current single zone automatic HVAC system, the user can only set one common temperature and air flow rate for the entire vehicle cabin. There is no provision for each passenger seat to have a unique temperature and air flow setting according to the
Deshmukh, Gaensh S.
Comparative Study Between OpenFOAM and STAR-CCM+ for HVAC Airflow Analysis2022-28-043711/09/2022
Vehicle air conditioning and heating system is one of the most important part of an automobile system. Computational fluid dynamics (CFD) is widely used to predict air flow rates and distribution in such HVACs. Commercial CFD codes such as FLUENT and STAR-CCM+ are widely used in simulation for industrial research. But usage of these software comes with a heavy cost. Cost is one such parameter where industries try to bring down, without compromising on the deliverables in product development. OpenFOAM is one such license free, open source code that can be used to modify and compile its code based on the needs and the physics of the problem in hand. This study assesses the performance of airflow magnitude and distribution in an HVAC using OpenFOAM. The assessment uses the same mesh with initial and boundary conditions. The results between STAR-CCM+ and OpenFOAM are compared in terms of grid-independent solutions using various scalar and vector plots. The results thus obtained is also
Baruah, Murchana
An Experimental Study for Reduction of Refrigerant Flow Induced Noise in a Passenger Vehicle2022-28-043911/09/2022
Air conditioning these days has become an indispensable part of human comfort due to rising global temperatures. Air conditioners are installed to achieve thermal comfort in enclosed spaces such as rooms, vehicle passenger cabins, laboratories etc. As the air conditioning units employ dynamic processes to maintain thermal comfort it creates many unwanted noises which lower the acoustic comfort. One of these unwanted noises is the refrigerant flow induced noise inside passenger cabin of an automobile when the air conditioning is switched on in a thermally soaked vehicle. This paper elaborates about the study done on a calorimetric bench inside a semi-anechoic environment for identification of the noise signature and its acoustic interpretation. It also compares the noise readings obtained on the bench and at vehicle level in a semi-anechoic setting. The paper discusses about the possible mechanism for the occurrence of the refrigerant flow induced noise. It also discusses about various
Sharma, Rachit, Kumar, Mukesh, Kumar, Shubham, Patra, Subhashree
Novel Approach Development for Air Conditioning Compressor Capacity Measurement2022-28-042811/09/2022
The actual compressor capacity is generally different from the theoretical capacity due to internal leakages, losses and manufacturing imperfections. Conventionally, compressors’ volumetric efficiency and compressor capacity is measured using system level (calorimeter) testing consisting of evaporator, condensor and TXV in a closed loop system with known refrigerants (R134, R1234yf etc.). In this paper a novel methodology is demonstrated and test rig developed for evaluating any automobile air conditioning compressors’ actual volumetric efficiency and capacity by using working fluid as atmospheric air in an open loop single phase system. Compressor of theoretical capacities 90, 110, 125, 140, 150 cm3/rev were tested and actual capacities were measured at different pressure ratios and compressor RPMs. The process parameters of the test rig were continuously monitored and readings were taken through data acquisition system. Comparative study is also presented for tested volumetric
Yadav, Aditya Pratap, Sharma, Kamal, Goel, Arun Kumar
Design of Hybrid Air Conditioning System Using Phase Change Material for Commercial Sleeper Vehicles2022-28-044811/09/2022
Many road accident happens due to fatigue & deprive sleep of drivers. Many times driver use AC system for their quick thermal comfort during night with engine ON. This scenario is very critical from human's safety & vehicle functionality point of view. This also consumes additional 10-15% of fuel requirements in AC running condition. So, to address social problems of driver's sleep & pollution free environment by reducing the use of fossil there is a need of alternative techniques for air cooling which works during engine OFF condition. Various alternatives options for air cooling have been reviewed & extensive evaluations are mapped on the various performance parameters. Based on this the phase change material technology can be easily adopted due to its packaging flexibility. Phase change material (PCM) technology available in the market since decades for the use of storing the thermal energy. Perhaps the use of PCM material in controlled manner in not fully known for longer period of
Shalgar, Sandeep, Nagarhalli, Prasanna V, BEDRE, PALLAVI, SRIVASTAVA, SARVESH, Tupe, Akshay
Mobile Air Conditioner Off the Grid Cooling Solution2022-28-045411/09/2022
MOBILE AIRCONDITIONER OFF THE GRID COOLING SOLUTION ABSTRACT Rooftop air conditioners are great to use at camp sites with power supply, and swamp coolers only work effectively in dry areas. Rooftop Air Conditioners have excellent cooling capacity. It cools down an entire van space but consumes huge amount of energy! Unable to take on the go. Swamp Cooler consumes less power. Ideal to use in dry climates. But once the humidity gets high, the swamp cooler will struggle to have any effect. And one will have to fill the unit with water manually. Window Air Conditioner is an inexpensive solution with good cooling effect, but it’s bulky, difficult to move, install and power. It blocks windows and damages easily on bumpy roads if fitted in vehicle. Solution for these problems and to bring endless possibilities to outdoor cooling is state of the art device called mobile Airconditioner that provides cooling on the go and off the grid. Concept design is made with special features like small size
SINGHAL, SUNNY
Airflow and Thermal Management of Off-Road Vehicle Cabin2022-28-045111/09/2022
Heating, ventilation and air conditioning systems play a crucial role in our day-to-day activities. With rise in global warming, leading to climate change, HVAC unit is the need of the hour. With average temperatures on the rise, it is quite imperative that the unit provides better thermal comfort to the passengers. Off-road vehicles like tractor, is also no exclusion. Tractor drivers have to experience adverse weather conditions out in the open field. Thus it is quite fundamental that sufficient airflow reaches every point inside the driver cabin, ensuring proper cool-down. To ensure proper distribution of airflow inside the cabin, optimization of HVAC unit needs to be properly carried out. The present study shows how an HVAC of an off-road vehicle is properly optimized with the help of Computational Fluid Dynamics. STAR-CCM+ v2021.2.1 is used as solver for the simulation. Airflow and cool-down simulation of inside cabin is also carried out in both initial and optimized design. The
Singh, Shobit Kumar
Improving the Performance of the Air Conditioning Unit in Different Locations of a City Bus and Lightening the Air Ducts2022-01-504406/03/2022
The focus of this study is to validate vehicle test results of the air conditioning (AC) unit in a city bus and perform a comparative computational fluid dynamics (CFD) analysis on homogenizing the cabin air distribution in different AC unit locations on the rooftop. To validate CFD practical results, a vehicle test was performed outdoor during the AC unit works. Obtained test results based on airflow rate inside AC unit and also measured velocity values on the front cabin of air duct were validated without completely modeling the whole AC unit and indoor cabin via CFD. With this simplified method, it is thought that this approach can give an idea for new prototype air duct designs in relevant industries. Another advantage to this approach is that it avoids high mesh density near the radial fans (blowers) placed on the AC unit. Foam placed in air ducts as insulation and air blockage material is also optimized for air distribution in the indoor cabin. In conclusion, several foams and
Özcan, Onur, Demirtaş, Servet, Yıldız, Alp Eren, Coşkun, Atakan
Simulation Of Air Conditioning System For Thermal Comfort Using Machine Learning techniques2022-26-122905/26/2022
This study is about the system which establishes a model for environmental factors such as temperature, humidity, and air velocity of thermal comfort indicators by implementing different Machine Learning technique. In this work the principal goal is analyzing air flow, distribution of temperature and pressure in the Living room. In order to achieve the goal the domain is consider which is divided in to discretized manner which will be further used to record the thermal sensation and airflow. For the same simulated environment the experiment will be conducted, which resulting in to forming the dataset with respect time, relative humidity, draft, temperature, air flow. By considering the recorded dataset, machine learning algorithm like SVM (Support Vector Machine), radial basis function for different kernels, Decision tree, XG Boost and Adaboost are used to create the model in Pythan. Finally, various performance metrics like accuracy, sensitivity and specificity for all techniques are
Shete, Prachi, raut, vaishnavi, Mandhare, Janhavi, Borgaonkar, Apeksha, Dorwat, Ajit
Further Analysis of the Blockage Phenomenon During the Testing of Bluff Automotive Bodies in Closed Wall Wind Tunnels2022-01-108503/29/2022
The difficulties of testing a bluff automotive body of sufficient scale to match the on-road vehicle Reynolds number in a closed wall wind tunnel has led to many approaches being taken to adjust the resulting data for the inherent interference effects. But it has been impractical if not impossible to experimentally analyze the effects that are actually occurring on and around the vehicle when these blockage interferences are taking place. The present study is an extension of earlier work by the author and similarly to that study uses the CFD analysis of several bodies of differing configurations to examine the interference phenomena in solid wall wind tunnels and the effects that they have on the pressures, forces and force increments experienced by the vehicle model. This is accomplished by executing a series of CFD configurations with varying sized of the cross section from 0.2% to 13% blockage enabling an approximation of free air conditions as a reference. The earlier work is
Gleason, Mark, Riegel , Eugen
Conversion of Carbon dioxide into useful acids and byproducts2022-01-022003/29/2022
Carbon dioxide capturing is necessary to prevent the change in climatic conditions and global warming. This study includes the capturing of carbon dioxide and the conversion of the captured carbon dioxide into useful commercial products. The study has been conducted in the exhaust gases of the highly used 1 ton split air conditioner in domestic applications. The equipment includes the carbon dioxide measuring device at the inlet and outlet. The exhaust gases coming out of the air conditioner are being measured by a digital flow meter and this ensures the mass flow rate of the gases into the unit. The processing unit has been enclosed with a polyvinyl chloride sheet to prevent exposure to the outside environment. In the presence of water two electrodes has been deployed for the conversion of carbon dioxide to carbonic acid and formic acid. For this a protective experimental container has been placed in the vicinity of the air conditioner outlet. The flow rates of the gases into the
B, Prabakaran, Chinni, Venkata Sai Sandeep
Study On Passenger Cabin Under Passive Radiative Cooling Film2022-01-021603/29/2022
Radiative cooling uses the space cold source to cool the object, and the radiative cooling film prepared based on its principle can reduce the fuel consumption of automobile air conditioning refrigeration. In this paper, according to the passive radiative cooling principle, taking SiO2 as the radiation cooling film of infrared radiation material, the theoretical cooling value of the passenger compartment of the automobile is calculated and analyzed based on the heat balance equation.The influence of radiative cooling film on the temperature field of passenger cabin was studied by finite element analysis.The results show that the cooling film made of SiO2 as passive radiation material has obvious cooling effect on passenger cabin.In the ambient temperature of 308.15K, the theoretical cooling temperature is 6.7K.When radiative cooling film is applied to automobiles, the cooling value of passenger cabin body, seat, instrument panel and other parts reaches 2.2K-5.1K, among which the
Peng, Chao Yi
Proposed Standards And Methods For Leak Testing Lithium-Ion Battery Packs Using Glycol-based Coolant With Empirically Derived Rejection Limits2022-01-084803/29/2022
Lithium-ion batteries are a highly suitable energy source for many applications, particularly in the automotive sector due to their high energy density and low self-discharge rate. During the production of battery cells, rapid detection of leaks is essential to achieve necessary lifetime service-life and safety requirements. Once assembled into packs, whether made of prismatic, cylindrical or pouch cells, packs must be cooled by common automotive thermal management systems, for example those employing engine coolant and radiator, and in which manufacturers must prevent various leak-producing defects that affect durability, longevity and safety Two types of cooling systems are used in automobiles, an active variant in which refrigerant, compressor, evaporator and heat exchanger are used to operate the air conditioning system, or a passive variant with a cooling medium, typically a water/glycol mixture, and a heat exchanger cooled by ambient air. While good industry standards are
Wetzig, Daniel, Blaufuß, Marc
Improving the design of automotive air conditioning compressors by predicting the minimum engagement voltage of electromagnetic clutches2022-01-020603/29/2022
In order to insure passengers comfort, automotive air conditioning compressors are designed to be operational in case of low battery voltage. However, the “minimum engagement voltage” of compressors is mostly driven by designers’ know-how and rely extensively on laboratory tests, which can lead to two issues: Costly design modifications if problems are detected too late in the validation phase and the necessity to perform several design iterations before reaching the desired target. This paper presents the benefit of predicting the minimum engagement voltage where both of these drawbacks can be avoided, leading to a more robust design process. The method was tested on an electromagnetic clutch whose purpose is to engage the compressor when the air conditioning is turned on by passengers. The magnetic field generated by the clutch was estimated using an electromagnetic simulation software. Coil design parameters, materials magnetic properties, clutch assembly geometry and air gaps were
PLUY, Nicolas, Ohk, Changheon
Experimental investigation on human thermal comfort in passenger compartment under actual air conditioning usage habits2022-01-021703/29/2022
With the popularization of automobiles, people’s driving time increases gradually. However, the accompanying problem is that the interior space of the vehicle passenger compartment is narrow and relatively closed. If drivers and passengers are permanently in the uncomfortable passenger compartment, they will feel tired, agitated, inattention, etc., which is prone to traffic accidents. This makes people gradually improve the requirements of driving comfort. And thermal comfort is an important aspect of vehicle comfort, which is closely related to the energy consumption of air conditioning. The thermal environment in the vehicle passenger compartment is a special non-uniform thermal environment. However, due to the complexity of the thermal environment inside the automobile, the basic research on human thermal comfort in the non-uniform thermal environment is carried out in the building environment. The non-uniform thermal environment in the building is mainly caused by the non-uniform
Xu, Xin, zhao, lanping
Development and Application of J3112: A/C Compressor Oil Separator Effectiveness Test Standard2022-01-021803/29/2022
SAE J-Standard J3112 – “A/C Compressor Oil Separator Effectiveness Test Standard” – was developed to provide an analytical means of determining if an a/c compressor with oil separator functionality meets the U.S. EPA criteria of a minimum 50% effectiveness in order to qualify for menu credits for greenhouse gas reduction, per CFR Title 40, §86.1868-12. From the start of the a/c efficiency credit program, OEMs could qualify for menu credit items without providing data on the effectiveness of the product being implemented, but EPA regulations required supporting data from 2020 MY through the end of the current published regulations in 2025 MY. J3112 was developed by the SAE Interior Climate Control MVAC Supplier Committee in order to provide a standardized procedure for determining oil separator effectiveness in order to comply with the EPA requirements for 2020-2025 model years. This presentation will provide background on how J3112 was developed, and how it is used in order to provide
Taylor, Dwayne
Physics-guided Sparse Identification of Nonlinear Dynamics for Prediction of Vehicle Cabin Occupant Thermal Comfort2022-01-018003/29/2022
Thermal cabin comfort is the largest consumer of battery energy second only to propulsion in Battery Electric Vehicles (BEV’s). Accurate prediction of thermal comfort in the vehicle cabin with fast turnaround times will allow engineers to study the impact of various thermal comfort technologies and develop energy efficient Heating, Ventilation and Air Conditioning (HVAC) systems. In this study a novel data-driven model based on physics-guided Sparse Identification of Nonlinear Dynamics (SINDy) method was developed to predict Equivalent Homogeneous Temperature (EHT), Mean Radiant Temperature (MRT) and cabin air temperature under transient conditions and drive cycles. EHT is a recognized measure of the total heat loss from the human body that can be used to characterize highly non-uniform thermal environments such as a vehicle cabin. The SINDy model was trained on drive cycle data from Climatic Wind Tunnel (CWT) for a representative Battery Electric Vehicle. The performance of the
Warey, Alok, Kaushik, Shailendra, Han, Taeyoung
Design, Development And Experimental Investigation On The Effect Of HVAC Power Consumption In Electric Vehicle Integrated With Thin Film Solar PV Panels.2021-28-023410/01/2021
Air conditioning systems are one of the significant auxiliary loads on the vehicle powertrain. In an Electric Vehicle (EV) where the available energy is limited, it becomes crucial to optimize the overall energy consumption of the auxiliary loads. The major power consuming components in an automotive HVAC system (Heating, Ventilation and Air Conditioning) are: Compressor, Cabin blower, Condenser cooling fan and the Control devices. Significant progress is already made in enhancing the energy efficiency of the above-mentioned power consuming components part of vehicle HVAC system. Alternate energy sources are being explored recently, to reduce the energy demand from vehicle. One such proposal is to harness the abundant solar energy available, through solar panels and consume this energy to supplement the power required for HVAC system components. Solar panels convert solar energy to electrical energy by the principle of the photovoltaic effect. A thin-film solar cell is a second
Srivastava, Shreekant, S, Karthikeyan, ARUMUGAM, PRABHAKARAN, Kumar, Anugu, Thanigaivel, Ganesan
Modelling of a Transient VCRS and Virtual Optimal Charge Determination for Automobiles2021-28-025510/01/2021
Experimental research on the Vapor Compression Refrigeration System (VCRS) used in automobiles and other air conditioning systems is abundant in literature but it comes with inherent problems like the cost of the setup, time consumption, and tediousness of the process. Therefore, the objective of this study is to develop the fully-fledged transient or dynamic model of R134a based VCRS and further utilize it to virtually determine the optimal refrigerant charge quantity. The Simulink model developed in this work is an integration of physics-based mathematical models for each component (compressor, heat exchangers, and expansion valve), working together in a cycle where the compressor dictates the transient process. A sample simulation has been performed by taking 5 bar as the initial pressure of suction and discharge tanks and the steady state results (Discharge pressure, suction pressure, refrigerant mass flow rate, superheat and subcool temperatures) obtained. The results are found to
Bhala, Parth, ghosh, Anirban, Dixit, Manas, Gokavarapu, Srikar, Shangar Ramani, Vagesh
Air Quality improvement in air conditioner bus saloon through Carbon activated filters2021-26-031209/22/2021
India being a developing nation, there is significant improvement in road infrastructure across the country as well as the spending power and earnings of the common man. This leads to the new trend of customers become health and comfort conscious and willing to pay more for better and improved transportation. To satisfy these demands, OEM's are developing more numbers of AC buses. Although the OEM's are meeting this demand of quantity, the quality of air from air conditioner is still subpar. One of the main reasons for this poor air quality is because of the ineffectiveness of conventional air conditioner air filters to control particulate materials i.e. PM2.5, biological pollutants i.e microbes, bacteria, viruses, and gaseous pollutants i.e. CO, CO2, SO2, NOX, O3 & VOCs in air. As per various researches, health problems associated with bus occupant compartment air quality appear more frequently. In this paper, research is shown on bus air quality improvement with respect to
Dwivedi, Ajay Kumar, Pahade, Atul, Thakur, Jitendra
Improved air distribution through new AC vent design for 3x2 seating layout in air Conditioning buses2021-26-031109/22/2021
With the improvement of standard of living, air-conditioning has widely been applied in buses. However, in air conditioning buses air distribution is still needs to be improved, One of the main reasons for this sub-quality comfort is two air flow louvers arrangement for 3x2 layout air conditioner buses. Air conditioning buses hatrack louvers are on integral part in providing comfort to passengers. General trend of the numbers of louvers provided to passengers is two louvers for three seats. Disadvantage of having conventional two louvers is that, there is always one passenger left with no option of directing air towards that person. This lead to an opportunity to design three louvers type hatrack instated of conventional two louvers hatrack, for 3x2 seating layout of buses. This way all three passengers can control the louvers for their own comfort and mass of air flow is sufficient for third passenger as well. This new design air distribution had been tested through CFD and air flow
Shende, Sushil, Pahade, Atul Ajit, Thakur, Jitendra, Chauhan, Nivedita, Singh, Sandeep
Optimized Power Utilization of Air Conditioner in Electric City Bus Using Occupant Detection2021-26-014209/22/2021
Electric vehicles have a limitation of limited range and long charging time. Energy optimization plays a very crucial role in determining the range of an electric vehicle. The innovative system proposed here gives the opportunity to reduce energy wastage and efficiently direct the electrical energy to improve the driving range of a 9 meter AC electric bus. The high voltage air conditioner unit alone consumes more than 40% of the electrical energy stored in the traction battery which reduces the driving range of the electric bus drastically. The proposed system optimizes the air conditioner utilization to direct cool air only in areas where passengers are present. Buses do not always run on full capacity, when there are less number of people in the bus the system detects the locations of the passengers using sensors and occupant detection algorithm, this enables the controller to identify the areas where cooling has to be focused and where cooling can be reduced or stopped. Once the
Nesamani, Kevin, Pandey, Ramakant, Jain, Rajesh
Feasibility of heating the air in a hybrid power unit with the pneumatic engine for a compact wheeled vehicle2021-01-124609/21/2021
The article proves the necessity for heating the air in the pneumatic engine of a hybrid power unit designed for moving a compact wheeled vehicle. The aim is to improve the pneumatic engine operation indicators by heating the compressed air before it is supplied to the cylinder using the obtained theoretical and experimental studies. For the easy-to-use of assessing the effectiveness of heating the air supplied to a pneumatic engine, the experiments were carried out by two speed indicators p_s = 0.7MPa and p_s = 0.9MPa, according to them the testing of a pneumatic unit was conducted without heating the compressed air at the temperature equal to the ambient temperature T_s = 293K. Also, during the experiments a pneumatic engine was tested at other temperatures while supplying the compressed air at the inlet to the engine cylinder. So, at an inlet pressure p_s = 0.7MPa, the compressed air was heated up to the temperature T_s = 383K, and at a pressure p_s = 0.9MPa it was heated up to the
Leontiev PhD, Dmitry, Voronkov, Oleksandr, Nikitchenko, Igor, Korohodskyi, Volodymyr, Ryzhykh, Leonid, Rudenko, Nataliia, Makarova, Tamara
Experimental Investigation On The Effect Of HVAC Power Consumption In Electric Vehicle Integrated With Thin Film Solar PV Panels.2021-28-012209/15/2021
Air conditioning systems are one of the significant auxiliary loads on the vehicle powertrain. In an Electric Vehicle (EV) where the available energy is limited, it becomes crucial to optimize the overall energy consumption of the auxiliary loads. The major power consuming components in an automotive HVAC system (Heating, Ventilation and Air Conditioning) are: Compressor, Cabin blower, Condenser cooling fan and the Control devices. Significant progress is already made in enhancing the energy efficiency of the above-mentioned power consuming components part of vehicle HVAC system. Alternate energy sources are being explored recently, to reduce the energy demand from vehicle. One such proposal is to harness the abundant solar energy available, through solar panels and consume this energy to supplement the power required for HVAC system components. Solar panels convert solar energy to electrical energy by the principle of the photovoltaic effect. A thin-film solar cell is a second
Srivastava, Shreekant, S, Karthikeyan, Kumar, Anugu, ARUMUGAM, PRABHAKARAN, Thanigaivel, Ganesan
Alternate Methodology for Air Conditioning Compressor Capacity Measurement2021-28-014109/15/2021
The actual compressor capacity is generally different from the theoretical capacity due to internal leakages and manufacturing imperfections. Conventionally, compressor volumetric efficiency is measured using system level testing consisting of evaporator, condensor & TXV in a closed loop system with known refrigerants. In this paper a methodology is demonstrated for evaluating any auto mobile air conditioning compressors' volumetric efficiency & capacity by using atmospheric air in an open loop system. Wide range of compressors (~70cc to ~220 cc) were tested and data generated. The process parameters of the test rig was continuously monitored until stabilization and readings were taken. It is observed that the results are comparable with closed loop performance results. Comparative study is presented for tested volumetric capacity and theoretically calculated value along with variations. Henceforth, the outlined approach gives deeper insight into design effectiveness, any imperfections
Yadav, Aditya Pratap, Goel, Arun Kumar, Sharma, Kamal
Study of various techniques for the reduction of Mobile Air Conditioning (MAC) compressors noise inside the passenger cabin2021-28-012609/15/2021
Due to stiff competition among the Original Equipment Manufacturer (OEM's), the Comfort, Fuel efficiency & Safety are the key factors that drives the vehicle business. The main factors of vehicle comfort are vibration, noise, thermal comfort (temperature), air quality, light and ergonomics. In this context Compressor Noise plays an important role in the comfort of the passengers. Therefore, it's a big challenge for the automotive engineer to find the source of noise and reduce the same during the development. The objective of this paper to understand the various compressors noise characteristic during static (i.e initial engagement of compressor) and dynamic condition (i.e during compressor running). Key words: Comfort, Compressor noise, NVH
Anandan, Ram, Venkateshwararao, Manchi, Patel, Yash
Attaining Thermal Comfort by Utilizing Polymer Dispersed Liquid Crystal Embedded Wind Shield and Roof of a Passenger Car2021-28-015109/15/2021
Thermal Comfort is necessary for the passenger cars for the rider and co-passengers while using the vehicle for a long-distance and in hot sunlight. This study is attaining thermal comfort in a passenger car by utilizing Polymer Dispersed Liquid Crystal embedded windshield and roof. The property of this glass is that the increase in the temperature changes the transparency into opaque such that the hot sunlight rays are not allowed to pass into the cabin of the passenger car. This enables the thermal discomfort caused by the hot sunlight during the daytime and at the parking place. This study has been conducted in a full experimental manner for a super sedan vehicle. Normal windshield and roofing used are not providing thermal comfort (25-27ᵒC) of cabin temperature although the air conditioner has been utilized. This increases the cabin temperature and consuming more power for the air conditioner to run. The top roof and the side windshield are utilized with polymer dispersed liquid
B, Prabakaran
Aero-acoustic optimization of flow-induced noise through biomimetic serrations on Automotive HVAC system components2021-28-013709/15/2021
The present work studies the effect of Owl Wing feather inspired Leading-edge serrations for minimizing Aero-Acoustic Noise. The aim of this research was to systematically study the effect of serrations by applying Box–Behnken experimental design for modeling the varied serrations in the Heating, ventilating and air conditioning (HVAC) system vent blade geometry. The variables of the serration model studied were Serration Height, Serration Thickness, Serration Spacing and the combination effect of variation in number of serrations. The Sound Pressure Levels at 1/3rd Octave bands in the Audible range of 800Hz to 4000Hz were studied and the Response Surface Response surface methodology approach was used for optimization of the process parameters and identifying the optima geometry parameters. An Optimized Geometry with 6 Serrations was found to have significant improvement in comparison to the No Serration base geometry. These results were further improved by Increasing the Maximum
Kaninghat, Sreeganesh, K, Srinivasan, Venkateshwararao, Manchi, Arumugam, Prabhakaran, Rudrakali, Ganesh
Measurement of Sound Power Due to Flow Noise at the Outlet of a Straight Pipe2021-01-105008/31/2021
Intake, exhaust, and heating / air conditioning systems in automobiles consist of various common duct elements. Noise arises primarily due to the source and is attenuated using common elements like expansion chambers and resonators. This attenuation is straightforward to predict using plane wave simulation and more advanced numerical methods. However, flow noise is often an unexpected important noise source. Predictions require computer intensive analyses. To better understand the aeroacoustic sources in duct systems, a flow rig has been developed at the University of Kentucky. The flow rig consists of a blower, a silencer to attenuate blower noise, external noise sources, and then the test duct. The flow rig can be equipped with an anechoic termination to measure transmission loss or may be used to measure insertion loss directly. In the latter case, the sound power is measured from the pipe outlet inside of a hemi-anechoic chamber. In this research, the external noise sources are
Donkin, Seth M., Herrin, D. W.
Numerical and Experimental Investigation and Refinement of Automotive HVAC Flow Induced Noise2021-01-105608/31/2021
Automotive heating ventilating and air conditioning (HVAC) noise is a very big concern for original equipment manufacturers (OEM) and suppliers. It turns out to be more challenging as the demand for acoustic comfort is increasing day by day. Many times an existing HVAC with some minor changes (mostly the vehicle fitment points) is proposed for face-lift vehicle but the performance expectation is far beyond the existing one due to market demand. One of the critical requirements is enhanced sound quality. To achieve that either experimental testing or numerical simulation is adopted. In either of these cases, it ends up with high number of experiments or increased simulation cost due to aero-acoustic simulation. Hence a combined approach is followed in order to investigate and improve the noise sources of an existing HVAC. The present paper describes this approach in details by doing numerical flow simulation followed by experimental investigation. HVAC was modeled using computational
Sen, Somnath
Simulation Driven Design of HVAC Systems under Competing HVAC Noise and Defrost Performance Requirements2021-01-102008/31/2021
It is particularly easy to get tunnel vision as a domain expert, and focus only on the improvements one could provide in their area of expertise. To make matters worse, many Original Equipment Manufacturers (OEMs) are silo-ed by domain of expertise, unconsciously promoting this single mindedness in design. Unfortunately, the successful and profitable development of a vehicle is dependent on the delicate balance of performance across many domains, involving multiple physics and departments. Taking for instance the design of a Heating, Ventilation & Air Conditioning (HVAC) system, the device’s primary function is to control the climate system in vehicle cabins, and more importantly to make sure that critical areas on the windshield can be defrosted in cold weather conditions within regulation time. With the advent of electric and autonomous vehicles, further importance is now also placed on the energy efficiency of the HVAC, and its noise. During the development of the defrost mode of an
Nagarajan, Vijaisri, Biermann, Jan, Goldberg, Jens, Motiwala, Hamza, Martins, Diogo, Luzzato, Charles, Mukutmoni, Devadatta
Basic Aircraft Oxygen Systems DesignAIR825/14 (Current)08/11/2021
This slash document collects general reference material related to gaseous oxygen system flow requirements and sizing calculations. This document will assist oxygen system equipment designers and operators to establish systems and equipment requirements. The document consists of charts, tables, system schematics, system requirements, and sample calculations for system sizing.
A-10 Aircraft Oxygen Equipment Committee
Organic Material for Next-Generation HVAC TechnologiesTBMG-3962408/01/2021
Heating, ventilation, and air conditioning (HVAC) systems often come with dehumidifiers but are currently not energy efficient, guzzling around 76% of the electricity in commercial and residential buildings. Researchers have determined that organic material called polyimides use less energy to dry air. Poly-imide-based dehumidifiers can bring down the price of HVAC systems, which currently cost thousands of dollars.
Recommended Practice for Processing and Handling Wire and Cable with Silver Plated Conductors and ShieldsARP6400 (Current)06/07/2021
This ARP specifies the recommended methods of handling silver coated conductors and shield, by the conductor fabricator, wireinsulator, distributors, harness or assembly houses, and OEM’s. Red Plague mitigation depends upon each link in the chain of supply handling the wire and cable properly.
AE-8D Wire and Cable Committee
Experimental Validation of Eco-Driving and Eco-Heating Strategies for Connected and Automated HEVs2021-01-043504/06/2021
This paper presents experimental results that validate eco-driving and eco-heating strategies developed for connected and automated vehicles (CAVs). By exploiting vehicle-to-infrastructure (V2I) communications, traffic signal timing, and queue length estimations, optimized and smoothed speed profiles for the ego-vehicle are generated to reduce energy consumption. Next, the planned eco-trajectories are incorporated into a real-time predictive optimization framework that coordinates the cabin thermal load (in cold weather) with the speed preview, i.e., eco-heating. To enable eco-heating, the engine coolant (as the only heat source for cabin heating) and the cabin air are leveraged as two thermal energy storages. Our eco-heating strategy stores thermal energy in the engine coolant and cabin air while the vehicle is driving at high speeds, and releases the stored energy slowly during the vehicle stops for cabin heating without forcing the engine to idle to provide the heating source. To
Amini, Mohammad Reza, Hu, Qiuhao, Wang, Hao, Feng, Yiheng, Kolmanovsky, Ilya, Sun, Jing
Control Strategies for Prevention of PEMFC Oxygen Starvation: A Review2021-01-074304/06/2021
Proton Exchange Membrane Fuel Cell (PEMFC) which has advantages of starting fast, high energy density, high efficiency, lower operating temperature and little pollution is widely regarded as one of the most promising energy sources. The PEMFC system includes several subsystems such as air supply subsystem, hydrogen supply subsystem, thermal management subsystem, water management subsystem, energy management subsystem and so on. The Air supply subsystem has great influence on the performance and life of PEMFC stack. Whether oxygen supply in air supply subsystem is sufficient or not will affects reaction rate of fuel, the operating temperature and degradation of PEMFC stack and so on. To solve the issue of oxygen starvation in PEMFC stack, the control strategies for improving dynamic response and preventing air shortage of the PEMFC air supply subsystem are reviewed. In this paper, the traditional proportional integral differential control, model predictive control, self-adaptive control
Gong, Dapeng, Xu, Sichuan, Zhang, Baitao
Autonomous Sensor Technology for Real-Time Feedback About Refrigeration and HeatingTBMG-3863803/01/2021
Researchers at Purdue University developed a sensor to monitor the oil circulation ratio (OCR) in real time for heating, ventilation, air conditioning and refrigeration systems. The oil circulation ratio provides data on the health and functionality of the overall system.
STANDARD FOR D.C. BRUSH MOTOR - HVAC BLOWERSUSCAR6-1 (Current)11/19/2020
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.
USCAR
STANDARD FOR D.C. BRUSH MOTOR - HVAC BLOWERSUSCAR6-1-TEST-REC (Historical)11/19/2020
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.
USCAR
Electricity-Free Radiative Cooling SystemTBMG-3798111/01/2020
Engineers have designed a system that can help cool buildings in crowded metropolitan areas without consuming electricity — an important innovation at a time when cities are working to adapt to climate change.
Performance Requirements for R-134a and R-1234yf Refrigerant Diagnostic Identifiers (RDI) for Use with Mobile Air Conditioning SystemsJ2912_202009 (Current)09/23/2020
Interior Climate Control Service Committee
The Potential of Exhaust Waste Heat Use in a Turbocharged Diesel Engine for Charge Air Cooling2020-01-208909/15/2020
Even a basic analysis of the use of fuel energy in a combustion engine would indicate that one-third of fuel energy is converted into exhaust waste, which is released into the environment. The scale of energy loss encourages scientists to try to consider the waste heat of exhaust gases as a potential source of useful energy. It is a standard today that waste heat is commonly used to power a turbocharger applied to internal combustion engines. Waste heat can also be used to drive an adsorption cooling system for air-conditioning inside the car. The drawback of that solution is complexity of the system and size of adsorption bed which make it not suitable for automotive industry use. The concept of increasing the capability of vehicles’ turbo engines can boost performance of turbo-charged engines through extra cooling of air being impelled into the combustion chamber of the engine. Cooling of the charge inside the intake manifold saves fuel and reduces nitric oxide emissions in exhaust
Danilecki, Krzysztof, Eliasz, Jacek
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