DEVELOPMENT OF FUZZY LOGIC CONTROL FOR VEHICLE AIR CONDITIONING SYSTEM

A vehicle air conditioning system is experimentally investigated. Measurements were taken during the experimental period at a time interval of one minute for a set point temperature of 22, 23 and 24oC with internal heat loads of 0, 1 and 2 kW. The cabin temperature and the speed of the compressor were varied and the performance of the system, energy consumption and energy saving ware analyzed. The main objective of the experimental work is to evaluate the energy saving obtained when the fuzzy logic control (FLC) algorithm, through an inverter, continuously regulates the compressor speed. It demonstrates better control of the compressor operation in terms of energy consumption as compared to the control by using a thermostat imposing On/Off cycles on the compressor at the nominal frequency of 50 Hz. The experimental set-up consists of original components from the air conditioning system of a compact passenger vehicle. The experimental results indicate that the proposed technique can save energy and improve indoor comfort significantly for vehicle air conditioning systems compared to the conventional (On/Off) control technique

Analisis Pengaruh Kinerja Keuangan Terhadap Harga Saham Perusahaan Manufaktur Yang Terdaftar Di Bursa Efek Indonesia 2012-2014

This study aims to determine the effect of the partial significant between the dividend per share (DPS), Earning Per Share (EPS), Price Earning Ratio (PER), Debt to Equity Ratio (DER), the Current Ratio (CR), Net Profit Margin (NPM ), Return on Assets (ROA) on stock price (Common Price) in Manufacturing Companies Listed on the Stock Exchange and to know significant influence between the dividend per share (DPS), Earning Per Share (EPS), Price Earning Ratio (PER), debt Equity Ratio (DER), the Current Ratio (CR), Net Profit Margin (NPM), Return on Assets (ROA) together on stock price (Common Price) in Manufacturing Companies Listed on the Stock Exchange. The sampling technique used in this research is purposive sampling. The sample used in this study were 71 companies that have positive earnings from 2012 to 2014 year stock in order to obtain 71 x 3 = 213 samples.Based on these results the variable DPS, EPS and ROA have partial significant influence on stock price. Variable PER, DER, NPM and CR does not have a partial significant influence on stock price. F test analysis results showed variable DPS, EPS, PER, DER, CR, NPM and ROA jointly significant effect on stock price. And this shows that the model used is fit. The coefficient of determination with adjusted-R2 of 0.933. This means that 93.3% Stock Price variable variation can be explained by the variable DPS, EPS, PER, DER, CR, NPM and ROA while the remaining 6.7% is explained by other factors outside the model studied

Energy Analysis for Air Conditioning System Using Fuzzy Logic Controller

 Reducing energy consumption and to ensure thermal comfort are two important considerations for the designing an air conditioning system. An alternative approach to reduce energy consumption proposed in this study is to use a variable speed compressor. The control strategy will be proposed using the fuzzy logic controller (FLC). FLC was developed to imitate the performance of human expert operators by encoding their knowledge in the form of linguistic rules. The system is installed on a thermal environmental room with a data acquisition system to monitor the temperature of the room, coefficient of performance (COP), energy consumption and energy saving. The measurements taken during the two hour experimental periods at 5-minutes interval times for temperature setpoints of 20oC, 22oC and 24oC with internal heat loads 0, 500, 700 and 1000 W. The experimental results indicate that the proposed technique can save energy in comparison with On/Off and proportional-integral-derivative (PID) control

Indoor temperature control and energy saving potential of split unit air conditioning system using fuzzy logic controller

Variable speed compressor offers a wider range of cooling capacity control according to the cooling load of the system. The on/off controller consumes larger energy as the compressor is always working at maximum speed despites the cooling load and continuously on and off to prevent from over cool the room. This study focused on the implementation of variable speed compressor to increase energy efficiency with better temperature control inside the room for split unit air conditioning system. The experiments are done at room temperature of 23 and 24°C with internal heat load of 500 and 1000 W. Monitoring system is applied to monitor the room temperature, energy consumption, energy saving and coefficient of performance. The proposed system indicates as much 37% of energy saving as compared to on/off controller

Effect of cylinder deactivation strategies on engine performances using one-dimensional simulation technique

In order to meet consumer and legislation requirements, big investments on key technology strategies have been made to ensure fuel consumption is reduced. Recent technologies for gasoline engines are lean combustion technologies (including direct injection and homogenous charged compression ignition), optimizing intake and exhaust valve timing with valve lift and also cylinder deactivation system (CDA) have been practised to improve the engine efficiency. The purpose of this study is to investigate the engine behavior when running at different cylinder deactivation (CDA) strategies. One-dimensional engine model software called GT-Power is used to predict the engine performances. Five strategies were considered namely normal mode, spark plug off mode, cylinder deactivation mode, intake normal with exhaust off mode, and intake off with exhaust normal mode. Engine performance outputs of each strategy are predicted and compared at BMEP of 3 bars with engine speed of 2500 rpm. Also, the effect of CDA strategies on in-cylinder pressure and pumping loss are performed. The study shows that all of these cylinder deactivation strategies are capable of reducing the pumping loss (PMEP) and fuel consumption, thus increasing the thermal efficiency of the engine. The results suggest that the most beneficial strategy for activating CDA is for the case whereby both the intake and exhaust valves are kept closed. This CDA mode capable of increasing brake thermal efficiency up to 22% at entire engine speeds operation. This strategy successfully reduced the BSFC. It was found that most of these cylinder deactivation strategies improve the engine performance during part load engine condition

The effect of liquid suction heat exchanger sub-cooler on performance of a freezer using R404A as working fluid

This study presents the effect of liquid-suction heat exchangers (LSHX) sub-cooler in a freezer. The LSHX sub-cooler is a method to increase the cooling capacity of the evaporator by lowering temperature at the condenser outlet. The decrease in temperature of the condenser outlet will cause a decrease in the quality refrigerant entering the evaporator. The lower the quality of the refrigerant entering the evaporator, the higher the cooling capacity produced by the evaporator. The LSHX sub-cooler utilizes a heat exchanger to transfer heat from the outlet of the condenser (liquid line) to the suction of the compressor. In the present study, three different LSHX sub-coolers in the freezer with cabin temperature settings of 0, -10 and -20oC were investigated. The results showed that the lowest and the highest of effectiveness of the heat exchanger were 0.28 and 0.58, respectively. The experimental results also showed that EER reduction is occurred at the cabin temperature setting of 0oC and -10oC, whereas the EER improvements were always occurred at the cabin temperature settings of -20oC

Analysis of The Effect of Institutional Ownership Profitability, Sales Growth And Leverage on Tax Avoidance on Construction Subsector Companies Listed on the Indonesia Stock Exchange

This study aims to analyze the Effect of Institutional Ownership, Profitability, Sales Growth, and Leverage Against Tax Avoidance In Construction Subsector Companies listed on the Indonesia Stock Exchange in 2017 –2019, this research consists of 16 Construction Subsector companies listed on the Stock Exchange Indonesian Effect. by using the type of associative research analysis with data design the panel is a combination of time series data and cross-sectional data. The type of data used is panel data (pooled data), Regression analysis panel data with Fixed Effect Model (FEM) estimation method and reviews 10 SV programs. Hypothesis testing carried out is the Coefficient of Determination Test (R Square), F Test, and t-test. The results of the study show that the institutional ownership variable affects negative and positive effects on tax avoidance, Profitability Variable positive effect, and positive effect on tax avoidance. Variable Sales growth has a positive and positive effect on tax evasion. Leverage has a negative and positive effect on tax evasion. Keywords: Institutional Ownership (KI), Profitability (ROA) Growth Sales (SG), Leverage and Tax Avoidance (ETR

Energy efficiency of a variable speed of the centralized air conditioning system using PID controller

PID control system for air-conditioning system in residence is presented in this manuscript. The control strategy is focused on low energy consumption and thermal comfort for indoor user. The algorithm is developed to control the compressor speed at an appropriate speed according to the temperature inside the controlled area using PID controller. Software is developed to measure and interface the system with controlling the system according to the algorithm. The temperature settings are 20, 22 and 24°C with internal heat load of 0 and 1000 Watt. The results obtained proved that the technique can lower the energy consumption and increased temperature control for better thermal comfort compared to on/off controller

Taguchi method for development of mass flow rate correlation using hydrocarbon refrigerant mixture in capillary tube

The capillary tube is an important control device used in small vapor compression refrigeration systems such as window air-conditioners, household refrigerators and freezers. This paper develops a non-dimensional correlation based on the test results of the adiabatic capillary tube for the mass flow rate through the tube using a hydrocarbon refrigerant mixture of 89.3% propane and 10.7% butane (HCM). The Taguchi method, a statistical experimental design approach, was employed. This approach explores the economic benefit that lies in studies of this nature, where only a small number of experiments are required and yet valid results are obtained. Considering the effects of the capillary tube geometry and the inlet condition of the tube, dimensionless parameters were chosen. The new correlation was also based on the Buckingham Pi theorem. This correlation predicts 86.67% of the present experimental data within a relative deviation of -10% to +10%. The predictions by this correlation were also compared with results in published literature