Murat Hosoz

Energy and Exergy Analyses of a Diesel Engine Fuelled with Various Biodiesels

This study deals with comparative energy and exergy analyses of a four-cylinder turbocharged diesel engine using two different biodiesel fuels, petroleum diesel fuel, and blends of the biodiesels with petroleum diesel. Utilizing experimental data obtained from steady-state tests, balances of energy and exergy rates for the engine were determined. Then, various performance parameters of the engine were evaluated for each fuel operation. It was found that the tested biodiesels offer almost the same energetic performance as petroleum diesel fuel, while the exergetic performance parameters usually follow similar trends with the corresponding energetic ones.

Performance prediction of a CI engine using artificial neural network for various SME and diesel fuel blends

This study deals with predicting performance parameters and exhaust emissions of a four-stroke, four-cylinder, direct injection diesel engine fuelled with soybean oil methyl ester and its blends with jet fuel, marine fuel and No. 2 diesel fuel using Artificial Neural Network (ANN) approach. For this aim, an ANN model for the engine was developed using experimental data, and the performance of the ANN predictions was measured by comparing them with the experimental results. It was revealed that the ANN approach can accurately predict the performance parameters and exhaust emissions of the diesel engine using various diesel and biodiesel fuels.

Energy and exergy analysis of an Automobile Heat Pump system

This study deals with energy and exergy analysis of an Automobile Heat Pump (AHP) system using R134a as the working fluid and ambient air as a heat source. An experimental AHP system consisting of original components from an Automobile Air Conditioning (AAC) system and some extra equipment was developed and instrumented. The system was operated in steady state under various ambient and return air conditions, while the compressor was driven at different speeds. The results show that the AHP can be used for supplementing the main comfort heating system of a vehicle producing insufficient waste heat.

Experimental performance analysis of an automotive heat pump system for electric vehicles using HFC134a as refrigerant

P transmission is an inevitable part in any automobile. The power from the prime mover (engine/motor) is transferred to the wheels using a suitable transmission system. Various designs of gearbox have been developed in the past. In this paper, an F-N-R (forward-neutral-reverse) gearbox with a compact spur-gear differential is designed by following the design parameters for spur gear, for the required output torque of a vehicle. All the gears and casing for the gearbox is modeled using Solidworks tool. A simple and user-friendly shifting mechanism is designed for the gearbox, adding to comfort. A new spur-gear differential is designed, having spur gears to accomplish differential action, which is more compact and light-weight compared to a conventional differential, since the heavy bevel gear assembly is omitted. Different analyses such as static, dynamic (time-dependent), contact, modal and fatigue analyses are done using ANSYS software. The main objective is to design and fabricate a light-weight, efficient and compact F-N-R gearbox as a replacement to current models.

Effect of ambient temperature on the performance characteristics of automotive air conditioning system using R1234yf and R134a: Energy and exergy-based approaches

This paper presents the comparative experimental results of an automotive air conditioning (AAC) system charged with refrigerants R1234yf and R134a which were analyzed to find the effect of increasing ambient temperature using energy and exergy-based approaches. The urgencies for such investigation are due to the demand of finding refrigerant both satisfy the performance and also compatible with Kyoto Protocol and EU f-gas regulation. For this aim, a bench-top experimental AAC system was constructed and tested at four different compressor speeds, namely 1000, 1500, 2000, and 2500 rpm. For each compressor speed, the temperatures of the air streams at the inlets of the inside duct was 30 °C and varies the outside duct, i.e. Tcond,ai, of 30, 35, and 40°C. It was revealed that the AAC system with R1234yf yield comparative performances shown by the higher mass flow rate, comparably less cooling capacity and COP than that of with R134a. The mass flow rates and power absorbed in the compressor get higher as Tcon...

Experimental Performance Analysis of an Automotive Air Conditioning and Heat Pump System using R134a with and without Internal Heat Exchanger

In this study an experimental system was set up from the original components of an automotive air conditioning (AAC) system. After than internal heat exchanger (IHX) and reversing valve were installed to use as heat pump and improve performance of it. For each mode of operations, the system was tested at five different compressor speeds between 800 and 2800 rpm with intervals of 400 rpm. In the heat pump mode operations without IHX, the temperatures of the air streams entering the evaporator and condenser were maintained at Tevap,ai=0°C – Tcond,ai=0°C, Tevap,ai=10°C –Tcond,ai=10°C and Tevap,ai=15°C – Tcond,ai=15°C. IHX was started up the temperatures of the air streams at the inlets of the evaporator and condenser were maintained at Tevap,ai=5°C – Tcond,ai=5°C, Tevap,ai=10°C – Tcond,ai=10°C and Tevap,ai=15°C – Tcond,ai=15°C. Using experimental data, performance parameters such as conditioned air stream temperature, compressor power, compressor mechanical power and compressor discharge temperature were evaluated. In heat pump mode provided enough heating capacity and conditioned air stream temperatures even at low compressor speeds. Furthermore, the heating capacity increased but COPh decreased with rising compressor speed however compressor power decreased and COPc increased with using IHX. Keywords—HFC134a, automotive air conditioning, internal heat exchanger. Erkutay TASDEMIRCI Kocaeli University Turkey Murat HOSOZ Kocaeli University Turkey

Energy and Exergy Analysis of an R134A Automotive Heat Pump System for Various Heat Sources in Comparison with Baseline Heating System

Performance of an automotive heat pump (AHP) system using R134a and driven by a diesel engine has been evaluated in this study. For this purpose, an experimental AHP system capable of providing a conditioned air stream by utilizing the heat absorbed from the ambient air, engine coolant and exhaust gas was developed. The experimental system was equipped with instruments for measuring engine torque and speed, refrigerant and coolant mass flow rates, refrigerant and air temperatures as well as refrigerant pressures. The system was tested by varying the engine speed, engine load and air temperatures at the inlets of the indoor and outdoor coils. Using experimental data, an energy analysis of the system was performed, and its performance parameters for each heat source were evaluated for transient and steady-state operations. Then, the performance of the AHP system for each source was compared with that of the system using other heat sources and with that of the baseline heating system. The investigated performance parameters include air temperature at the outlet of the indoor coil, heating capacity, coefficient of performance and exergy destruction rates in the components of the AHP system. The total exergy destruction rate in the AHP with engine coolant is higher than those in the AHP with ambient air and with exhaust gas mainly because of the greater refrigerant mass flow rate and heating capacity.

Experimental performance of an automobile air conditioning system using a variable capacity compressor for two different types of expansion devices

An experimental R134a automotive air conditioning (AAC) system with a variable capacity compressor has been developed and equipped with various mechanical instruments. The system has the capability of using both a thermostatic expansion valve (TXV) and an orifice tube (OT) as an expansion device. The system has been tested by varying the compressor speed and temperatures of the air streams entering the condenser (Tcond,ai) and evaporator (Tevap,ai). Using experimental data, the performance parameters of the AAC system for TXV and OT operations have been evaluated. The results show that the cooling capacity usually increases with the compressor speed. However, the exergy destruction in the system also increases and the coefficient of performance (COP) decreases with the compressor speed. The cooling capacity and COP decrease on rising Tcond,ai, while they increase on rising Tevap,ai. The TXV operation usually yields slightly higher cooling capacity and COP and lower exergy destruction compared with OT operation.