mat nawi wan hassan - Academia.edu (original) (raw)

Papers by mat nawi wan hassan

Due to cost problem (e.g. fuels and electricity), energy cases are an urgent need to solve specia... more Due to cost problem (e.g. fuels and electricity), energy cases are an urgent need to solve specially in industrialized country, like Malaysia. Variable speed at compressor by using of manual (without control system) and control system have been purposed in air conditioning system, it has big potency in the effort of usage electrics energy saving. In this research, the usage of central type air conditioning with capacities 3 kW, with nominal motor rotation is 1450 rpm. Base on reference, the room temperature is 22 o C while the motor rotation variation are : 20, 25, 30, 35, 40, 45, and 50 Hz. Our results indicated that the value of electric energy saving consumption is 20,77 % at motor frequency 40 Hz, and 22,54 % by using proportional control systems.

Buku ini mengandungi beberapa bab iaitu kandungan: kata penghantar, simbol utama (tatanama), bab ... more Buku ini mengandungi beberapa bab iaitu kandungan: kata penghantar, simbol utama (tatanama), bab 1 konsep asas, konsep bendalir, sifat-sifat bendalir, pengelasan bendalir, bab 2 statik bendalir, tegangan (atau tekanan) pada suatu titik (hukum pascal), persamaan asas bagi statik bendalir, keseimbangan statik bagi bendalir boleh mampat, bab 3 kinematik aliran, medan aliran, aliran tetap dan aliran seragam, garis arus, garis laluan, garis strik, bab 4 bahagian a: persamaan asas bagi sistem dan isipadu kawalan, persamaan keterusan, persamaan momentum lelurus, persamaan momentum sudut, bahagian b: persamaan asas dalam bentuk kebezaan, persamaan momentum, penyelesaian persamaan navier-stokes, bab 5 analisis dimensa dan similitud, dimensa kuantiti fizik, kehomogenan dimensa, kegunaan analisa dimensa, bab 6 aliran di dalam paip, pembentukan aliran, aliran laminar, aliran gelora, bibliografi serta lampiran

Jurnal Teknologi, 1992

This paper describes a Simplified Hourly Energy Analysis Package (SHEAP) for the computation of a... more This paper describes a Simplified Hourly Energy Analysis Package (SHEAP) for the computation of annual energy consumption in non-residential buildings. The package, developed at the Mechanical Engineering Faculty, uses the transmission matrix method in calculating conduction heat gains through opaque building sections, and adopts the weighting factor method for the calculations of cooling loads, heat extraction rates and actual space •air dry bulb temperatures. Typical da: 1 y profiles of measured hourly weather data are used to approximate the external climatic conditions over a one-year period. A preliminary validation study indicates that SHEAP produces, reasonably good estimates when compared to the predictions by BUNYIP, a commercial building energy analysis package.

Jurnal Teknologi, 1994

The energy performance of a four-storey library (PSZ) building of Universiti Teknologi Malaysia (... more The energy performance of a four-storey library (PSZ) building of Universiti Teknologi Malaysia (UTM) has been simulated using a microcomputer-based building energy simulation program, SHEAP. The simulation results give a comparative estimate of the potential annual savings for nine parameters. Significant savings (greater than 3.7% of RM 815,680 in operating cost) can result from the use of a Variable Air Volume (VAV) system, reduced air-conditioning times and reduced electrical lighting intensity. A 25% glazed-facade can contribute about 1% in saving,while the other parameters contribute less than 0.2% in savings to be of any significance.

Jurnal Teknologi, 1987

Satu skim numerik yang cekap telah dibina untuk menyelesaikan persamaan aliran bendalir dan tenag... more Satu skim numerik yang cekap telah dibina untuk menyelesaikan persamaan aliran bendalir dan tenaga. Persamaan pembeza separa eliptik dari persamaan pengawal diubah kepada skim beza terhingga dengan menggunakan grid berselang dan pendekatan isipadu terkawal. Aturcara ini menyelesaikan satu pasang persamaan serentak taklinear dengan menggunakan cara Newton dan teknik matriks renggang. Cara ini tidak memerlukan pengendur bawah atau teknik cepat menumpu sebagaimana digunakan di dalam skim lelar biasa. Walau bagaimanapun, pengendur bawah yang sederhana dapat digunakan, dengan demikian jumlah masa pengiraan makin berkurang. Satu aliran gerakan apungan diaruhkan ke dalam suatu lingkungan dinding isotermal pugak yang panas dan sejuk telah diselesaikan pada Ra=106. Cara yang digunakan cepat menumpu dan cara ini dapat dilakukan untuk nombor Rayleigh yang lebih besar dan mungkin untuk jenis aliran lain. Kertas ini melaporkan aturcara, hasil dari perkiraan dan perbandingan dengan data numerik y...

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2007

Many air-conditioning (AC) systems are designed to operate at maximum cooling capacity regardless... more Many air-conditioning (AC) systems are designed to operate at maximum cooling capacity regardless of the variation in the daily cooling load. At low loads, the conditions can be uncomfortably cold and the overcooling is an unnecessary waste of energy. To address these two issues, a multiple refrigeration circuit concept is proposed and applied to a roof-top bus AC system. A two-circuit model is proposed for a standard bus size in which each circuit has two evaporators of equal sizes arranged in parallel and installed on each passenger row, respectively. This means that each passenger row is served by two different evaporators sharing a common heat exchanger box. Depending on the cooling load, this concept allows one or both circuits (compressor motors) to be switched on and during either modes, it also allows one or more sets of evaporator blowers to be switched on. A steady-state computer model has been developed to simulate the performance of the proposed two-circuit AC system. A ...

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2007

The current paper presents a methodology of a design optimization technique that can be useful in... more The current paper presents a methodology of a design optimization technique that can be useful in assessing the best configuration of a finned-tube condenser, using a thermal and economical optimization approach. The assessment has been carried out on an air-cooled finned-tube condenser of a vapour compression cycle for a roof-top bus air-conditioning system at a specified cooling capacity. The methodology has been conducted by studying the effect of some operational and geometrical design parameters for the condenser on the entire cycle exergy destruction or irreversibility, air-conditioning system coefficient of performance (COP), and total annual cost. The heat exchangers for the bus air-conditioning system are featured by a very compact frontal area due to the stringent space limitations and structure standard for the system installation. Therefore, the current study also takes in its account the effect of the varying design parameters on the condenser frontal area. The irrevers...

The demand for the compressor for the HVAC application is always on the increase particularly for... more The demand for the compressor for the HVAC application is always on the increase particularly for the compressor of the scroll type .The popularity and high demand for the scroll compressor are due to the technological development that makes the compressor more efficient and attractive. This paper discusses the analytical and the experimental determinations of the p-v diagram and mass flow rate for the scroll compressor on the scroll compressor. The experimental evaluation for the pressure volume diagram was made using four piezo-electric transducers at selected positions to obtain the pressure-crank angle with the help of data acquisition and software. An analytical model was also developed. The model takes into account the leakage at the flank and at the tip of the scroll compressor. The simulation studies were carried out under different leakage clearances. The paper further discusses the heat transfer loss, and the thermal contact loss between the fixed and the orbit scrolls. The analysis includes the conduction heat transfer through the bases of the orbit and the fixed scroll, and the convection heat transfer between the refrigerant and the scroll walls in the suction port. The experimental and computed results were compared at different working conditions and found to be in a good agreement.

International Journal of Energy Research, 2008

Clean Technologies and Environmental Policy, 2006

The potential of a variable-speed compressor running on a controller to provide enhanced load-mat... more The potential of a variable-speed compressor running on a controller to provide enhanced load-matching capability, energy saving and thermal comfort for application in air-conditioning system is demonstrated. An air-conditioning system, originally operated on a constant speed mode, is retrofitted with an inverter and a PID controller. The system was installed to a thermal environmental room together with a data acquisition

... Item Type: Conference or Workshop Item (Paper). Subjects: T Technology > TJ Mechanical eng... more ... Item Type: Conference or Workshop Item (Paper). Subjects: T Technology > TJ Mechanical engineering and machinery. Divisions: Mechanical Engineering. ID Code: 22639. Deposited By: Liza Porijo. Last Modified: 16 Feb 2012 04:38. Repository Staff Only: item control page. ...

... Nasution, Henry and Musa, Md Nor and Abdullah, Hayati and Wan Hassan, Mat Nawi and Baharain, ... more ... Nasution, Henry and Musa, Md Nor and Abdullah, Hayati and Wan Hassan, Mat Nawi and Baharain, Mohammad Akmal and Sulaiman, Sapiah and Mansour, Mohamed Khamis (2008) Potential energy saving by variable speed ... Deposited By: Dr Abd Rahim Abu Bakar. ...

Energy Conversion and Management, 2008

A novel control strategy to improve energy efficiency and to enhance passengers' thermal comfort ... more A novel control strategy to improve energy efficiency and to enhance passengers' thermal comfort of a new roof top bus multiple circuit air conditioning (AC) system operating on partial load conditions is presented. A novel strategy for automatic control of the AC system was developed based on numerous experimental test runs at various operating conditions, taking into account energy saving and thermal comfort without sacrificing the proper cycling rate of the system compressor. For this task, more than 50 test runs were conducted at different set point temperatures of 21, 22 and 23°C. Fanger's method was used to evaluate passenger thermal comfort, and the system energy consumption was also calculated. A performance comparison between that of the conventional AC system and that of the newly developed one has been conducted. The comparison revealed that the adopted control strategy introduces significant improvements in terms of thermal comfort and energy saving on various partial load conditions. Potential energy saving of up to 31.6% could be achieved. This results in a short payback period of 17 months. It was found from the economic analysis that the new system is able to save approximately 20.0% of the life cycle cost.

Jurnal Teknologi, 2014

A study on ventilation system using a two dimensional turbulence k-e model with the assumption th... more A study on ventilation system using a two dimensional turbulence k-e model with the assumption that the fluid is incompressible and non-isothermal is presented. The purpose of this study is to predict the distribution of air velocity and temperature in main hall Masjid Sultan Salahuddin Abdul Aziz Shah in Shah Alam. When the airflow and temperature distribution have been predicted by the computer software FLUENT, the comfort level can easily be determined. Nine cases have been conducted to examine the effects of input air velocity, air velocity from the fan heli and fan air flow direction to the percentage of consumer dissatisfaction. Mixing characteristics of comfort have been analyzed under different air supply velocities, temperatures and fan velocities. The fan velocity directions involved two conditions which are the upwards and downwards directions. The results from the research in the form of air velocity and temperature distributions are important in determining the comfort...

A scroll-wrap profile is an important factor affecting the performance and reliability of scroll ... more A scroll-wrap profile is an important factor affecting the performance and reliability of scroll fluid machines. A number of geometric curves have been used to form the working surfaces of the scroll machines. The involute of a basic circle is widely used in the design of the scroll compressor. This type of curve is characterized by its variable curvature, hence in manufacturing the machine tools needed a special software to produce the required curvature. In this paper a new profile known as "The Basic Hexagonal involute" has been studied in an attempt to make the manufacturing of the scroll easier, accurate and without the use of the software. This paper discusses the method of designing this profile, and the determination of its volumes. The paper also discusses a comparison between the new hexagonal involute, the basic circle, and square involute. The comparison includes the volume and the arc length for leakage, which affect directly on the performance of the scroll compressor. The thermodynamic comparison analysis for the basic circle and hexagonal are also included

Due to cost problem (e.g. fuels and electricity), energy cases are an urgent need to solve specia... more Due to cost problem (e.g. fuels and electricity), energy cases are an urgent need to solve specially in industrialized country, like Malaysia. Variable speed at compressor by using of manual (without control system) and control system have been purposed in air conditioning system, it has big potency in the effort of usage electrics energy saving. In this research, the usage of central type air conditioning with capacities 3 kW, with nominal motor rotation is 1450 rpm. Base on reference, the room temperature is 22 o C while the motor rotation variation are : 20, 25, 30, 35, 40, 45, and 50 Hz. Our results indicated that the value of electric energy saving consumption is 20,77 % at motor frequency 40 Hz, and 22,54 % by using proportional control systems.

Buku ini mengandungi beberapa bab iaitu kandungan: kata penghantar, simbol utama (tatanama), bab ... more Buku ini mengandungi beberapa bab iaitu kandungan: kata penghantar, simbol utama (tatanama), bab 1 konsep asas, konsep bendalir, sifat-sifat bendalir, pengelasan bendalir, bab 2 statik bendalir, tegangan (atau tekanan) pada suatu titik (hukum pascal), persamaan asas bagi statik bendalir, keseimbangan statik bagi bendalir boleh mampat, bab 3 kinematik aliran, medan aliran, aliran tetap dan aliran seragam, garis arus, garis laluan, garis strik, bab 4 bahagian a: persamaan asas bagi sistem dan isipadu kawalan, persamaan keterusan, persamaan momentum lelurus, persamaan momentum sudut, bahagian b: persamaan asas dalam bentuk kebezaan, persamaan momentum, penyelesaian persamaan navier-stokes, bab 5 analisis dimensa dan similitud, dimensa kuantiti fizik, kehomogenan dimensa, kegunaan analisa dimensa, bab 6 aliran di dalam paip, pembentukan aliran, aliran laminar, aliran gelora, bibliografi serta lampiran

Jurnal Teknologi, 1992

This paper describes a Simplified Hourly Energy Analysis Package (SHEAP) for the computation of a... more This paper describes a Simplified Hourly Energy Analysis Package (SHEAP) for the computation of annual energy consumption in non-residential buildings. The package, developed at the Mechanical Engineering Faculty, uses the transmission matrix method in calculating conduction heat gains through opaque building sections, and adopts the weighting factor method for the calculations of cooling loads, heat extraction rates and actual space •air dry bulb temperatures. Typical da: 1 y profiles of measured hourly weather data are used to approximate the external climatic conditions over a one-year period. A preliminary validation study indicates that SHEAP produces, reasonably good estimates when compared to the predictions by BUNYIP, a commercial building energy analysis package.

Jurnal Teknologi, 1994

The energy performance of a four-storey library (PSZ) building of Universiti Teknologi Malaysia (... more The energy performance of a four-storey library (PSZ) building of Universiti Teknologi Malaysia (UTM) has been simulated using a microcomputer-based building energy simulation program, SHEAP. The simulation results give a comparative estimate of the potential annual savings for nine parameters. Significant savings (greater than 3.7% of RM 815,680 in operating cost) can result from the use of a Variable Air Volume (VAV) system, reduced air-conditioning times and reduced electrical lighting intensity. A 25% glazed-facade can contribute about 1% in saving,while the other parameters contribute less than 0.2% in savings to be of any significance.

Jurnal Teknologi, 1987

Satu skim numerik yang cekap telah dibina untuk menyelesaikan persamaan aliran bendalir dan tenag... more Satu skim numerik yang cekap telah dibina untuk menyelesaikan persamaan aliran bendalir dan tenaga. Persamaan pembeza separa eliptik dari persamaan pengawal diubah kepada skim beza terhingga dengan menggunakan grid berselang dan pendekatan isipadu terkawal. Aturcara ini menyelesaikan satu pasang persamaan serentak taklinear dengan menggunakan cara Newton dan teknik matriks renggang. Cara ini tidak memerlukan pengendur bawah atau teknik cepat menumpu sebagaimana digunakan di dalam skim lelar biasa. Walau bagaimanapun, pengendur bawah yang sederhana dapat digunakan, dengan demikian jumlah masa pengiraan makin berkurang. Satu aliran gerakan apungan diaruhkan ke dalam suatu lingkungan dinding isotermal pugak yang panas dan sejuk telah diselesaikan pada Ra=106. Cara yang digunakan cepat menumpu dan cara ini dapat dilakukan untuk nombor Rayleigh yang lebih besar dan mungkin untuk jenis aliran lain. Kertas ini melaporkan aturcara, hasil dari perkiraan dan perbandingan dengan data numerik y...

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2007

Many air-conditioning (AC) systems are designed to operate at maximum cooling capacity regardless... more Many air-conditioning (AC) systems are designed to operate at maximum cooling capacity regardless of the variation in the daily cooling load. At low loads, the conditions can be uncomfortably cold and the overcooling is an unnecessary waste of energy. To address these two issues, a multiple refrigeration circuit concept is proposed and applied to a roof-top bus AC system. A two-circuit model is proposed for a standard bus size in which each circuit has two evaporators of equal sizes arranged in parallel and installed on each passenger row, respectively. This means that each passenger row is served by two different evaporators sharing a common heat exchanger box. Depending on the cooling load, this concept allows one or both circuits (compressor motors) to be switched on and during either modes, it also allows one or more sets of evaporator blowers to be switched on. A steady-state computer model has been developed to simulate the performance of the proposed two-circuit AC system. A ...

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2007

The current paper presents a methodology of a design optimization technique that can be useful in... more The current paper presents a methodology of a design optimization technique that can be useful in assessing the best configuration of a finned-tube condenser, using a thermal and economical optimization approach. The assessment has been carried out on an air-cooled finned-tube condenser of a vapour compression cycle for a roof-top bus air-conditioning system at a specified cooling capacity. The methodology has been conducted by studying the effect of some operational and geometrical design parameters for the condenser on the entire cycle exergy destruction or irreversibility, air-conditioning system coefficient of performance (COP), and total annual cost. The heat exchangers for the bus air-conditioning system are featured by a very compact frontal area due to the stringent space limitations and structure standard for the system installation. Therefore, the current study also takes in its account the effect of the varying design parameters on the condenser frontal area. The irrevers...

The demand for the compressor for the HVAC application is always on the increase particularly for... more The demand for the compressor for the HVAC application is always on the increase particularly for the compressor of the scroll type .The popularity and high demand for the scroll compressor are due to the technological development that makes the compressor more efficient and attractive. This paper discusses the analytical and the experimental determinations of the p-v diagram and mass flow rate for the scroll compressor on the scroll compressor. The experimental evaluation for the pressure volume diagram was made using four piezo-electric transducers at selected positions to obtain the pressure-crank angle with the help of data acquisition and software. An analytical model was also developed. The model takes into account the leakage at the flank and at the tip of the scroll compressor. The simulation studies were carried out under different leakage clearances. The paper further discusses the heat transfer loss, and the thermal contact loss between the fixed and the orbit scrolls. The analysis includes the conduction heat transfer through the bases of the orbit and the fixed scroll, and the convection heat transfer between the refrigerant and the scroll walls in the suction port. The experimental and computed results were compared at different working conditions and found to be in a good agreement.

International Journal of Energy Research, 2008

Clean Technologies and Environmental Policy, 2006

The potential of a variable-speed compressor running on a controller to provide enhanced load-mat... more The potential of a variable-speed compressor running on a controller to provide enhanced load-matching capability, energy saving and thermal comfort for application in air-conditioning system is demonstrated. An air-conditioning system, originally operated on a constant speed mode, is retrofitted with an inverter and a PID controller. The system was installed to a thermal environmental room together with a data acquisition

... Item Type: Conference or Workshop Item (Paper). Subjects: T Technology > TJ Mechanical eng... more ... Item Type: Conference or Workshop Item (Paper). Subjects: T Technology > TJ Mechanical engineering and machinery. Divisions: Mechanical Engineering. ID Code: 22639. Deposited By: Liza Porijo. Last Modified: 16 Feb 2012 04:38. Repository Staff Only: item control page. ...

... Nasution, Henry and Musa, Md Nor and Abdullah, Hayati and Wan Hassan, Mat Nawi and Baharain, ... more ... Nasution, Henry and Musa, Md Nor and Abdullah, Hayati and Wan Hassan, Mat Nawi and Baharain, Mohammad Akmal and Sulaiman, Sapiah and Mansour, Mohamed Khamis (2008) Potential energy saving by variable speed ... Deposited By: Dr Abd Rahim Abu Bakar. ...

Energy Conversion and Management, 2008

A novel control strategy to improve energy efficiency and to enhance passengers' thermal comfort ... more A novel control strategy to improve energy efficiency and to enhance passengers' thermal comfort of a new roof top bus multiple circuit air conditioning (AC) system operating on partial load conditions is presented. A novel strategy for automatic control of the AC system was developed based on numerous experimental test runs at various operating conditions, taking into account energy saving and thermal comfort without sacrificing the proper cycling rate of the system compressor. For this task, more than 50 test runs were conducted at different set point temperatures of 21, 22 and 23°C. Fanger's method was used to evaluate passenger thermal comfort, and the system energy consumption was also calculated. A performance comparison between that of the conventional AC system and that of the newly developed one has been conducted. The comparison revealed that the adopted control strategy introduces significant improvements in terms of thermal comfort and energy saving on various partial load conditions. Potential energy saving of up to 31.6% could be achieved. This results in a short payback period of 17 months. It was found from the economic analysis that the new system is able to save approximately 20.0% of the life cycle cost.

Jurnal Teknologi, 2014

A study on ventilation system using a two dimensional turbulence k-e model with the assumption th... more A study on ventilation system using a two dimensional turbulence k-e model with the assumption that the fluid is incompressible and non-isothermal is presented. The purpose of this study is to predict the distribution of air velocity and temperature in main hall Masjid Sultan Salahuddin Abdul Aziz Shah in Shah Alam. When the airflow and temperature distribution have been predicted by the computer software FLUENT, the comfort level can easily be determined. Nine cases have been conducted to examine the effects of input air velocity, air velocity from the fan heli and fan air flow direction to the percentage of consumer dissatisfaction. Mixing characteristics of comfort have been analyzed under different air supply velocities, temperatures and fan velocities. The fan velocity directions involved two conditions which are the upwards and downwards directions. The results from the research in the form of air velocity and temperature distributions are important in determining the comfort...

A scroll-wrap profile is an important factor affecting the performance and reliability of scroll ... more A scroll-wrap profile is an important factor affecting the performance and reliability of scroll fluid machines. A number of geometric curves have been used to form the working surfaces of the scroll machines. The involute of a basic circle is widely used in the design of the scroll compressor. This type of curve is characterized by its variable curvature, hence in manufacturing the machine tools needed a special software to produce the required curvature. In this paper a new profile known as "The Basic Hexagonal involute" has been studied in an attempt to make the manufacturing of the scroll easier, accurate and without the use of the software. This paper discusses the method of designing this profile, and the determination of its volumes. The paper also discusses a comparison between the new hexagonal involute, the basic circle, and square involute. The comparison includes the volume and the arc length for leakage, which affect directly on the performance of the scroll compressor. The thermodynamic comparison analysis for the basic circle and hexagonal are also included