• Journal of Energy Engineering
• /
• v.23 no.3
• /
• pp.1-6
• /
• 2014

The more or less homogeneous fuel-air mixture that exists at the end of the compression process is ignited by an electric ignition spark from a spark plug shortly before top dead center. The actual moment of ignition is an optimization parameter; it is adapted to the engine operation so that an optimum combustion process is obtained. Brake mean effective pressure (BMEP) of the spark ignition energy control device (IECD) than conventional spark system at the stoichiometric mixture is increased about 9%. For lean burn engine, the lean limit is extended about 25% by using the IECD. It was considered the stability of combustion by the increase of flame kernel according to the high ignition energy supplies in initial period and discharge energy period lengthen by using the IECD.

• Journal of Acupuncture Research
• /
• v.26 no.1
• /
• pp.111-119
• /
• 2009

Objectives : The purpose of this study is to investigate the mechanism and effect of moxa bucket moxibustion, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxa bucket moxibustion. Methods : We have selected the moxa bucket moxibustion. We have made a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We have examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results : 1. We could design the moxa bucket moxibustion so that it has $57.6^{\circ}C$ maximum temperature with 7g weight and 10mm height, if we use more weight of moxa or lower height of moxa, we can observe relatively elevated maximum temperature. We observed the maximum temperature following the measuring position of moxa bucket and we could see higher temperature at the center of the moxa bucket and lower temperature at the side of the moxa bucket. 2. We could design the moxa bucket moxibustion with 5g moxa and 10mm height so that it has 0.12 $1^{\circ}C/sec$ of maximum temperature gradient, and it has relatively high temperature gradient at lower weight and height condition. 3. We could design the moxa bucket moxibustion with 7g moxa and 15mm height so that it has 4,135sec of the longest effective temperature combustion time. If we use more weight of moxa or higher height of moxa, we can observe relatively extended effective temperature combustion time. Conclusions : We observed the longest effective combustion time following the measuring position of moxa bucket. We can see a higher temperature at the center of the moxa bucket and a lower temperature at the side of the moxa bucket.

• Journal of Acupuncture Research
• /
• v.24 no.1
• /
• pp.49-77
• /
• 2007

Objectives: The purpose of this study is to investigate the mechanism and effect of moxa bucket moxibustion. Objectively, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxa bucket moxibustion. Methods: We have selected of the moxa bucket moxibustion. We make a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results: 1. We can design the moxa bucket moxibustion that it has 57.6$^{\circ}C$ maximum temperature with 7g weight and 10mm height, if we use more weight of moxa or lower the height of moxa, we can observe relatively elavated maximum temperature. We observe the maximum temperature following the measuring position of moxa bucket and we can see higher temperature at the center of the moxa bucket and lower temperature at the side of the moxa bucket. 2. We can design the moxa bucket moxibustion with 5g moxa and 10mm height that it has 0.121 $^{\circ}C$/sec of maximum temperature gradient, and it has relatively high temperature gradient at lower weight and height condition. 3. We can design the moxa bucket moxibustion with 7g moxa and 15mm height that it has 4,135sec of the longest effective temperature combustion time, if we use more weight of moxa or higher height of moxa, we can observe relatively extended effective temperature combustion time. We observe the longest effective combustion time following the measuring position of moxa bucket. We can see higher temperature at the center of the moxa bucket and lower temperature at the side of the moxa bucket.

• Journal of Energy Engineering
• /
• v.11 no.2
• /
• pp.178-185
• /
• 2002

The object of this paper is to investigate the effects of early fuel evaporators on cold driveability of gasoline passenger cars. Experiment has been carried out for the assessment cold start performance and cold driveability. And fuel consumption rate, emission and cylinder pressure were measured. On the base of combustion pressure of cylinder, rate of heat release, cumulative heat release amount and burned mass fraction are evaluated. The results show that fuel consumption rate is increased by 17.7%, monoxide and hydrocarbon were reduced by 23% and by 45% respectively, fluctuations of indicated mean effective pressure and maximum combustion pressure were increased by 4∼6%, fuel consumption rate per power was improved by 0.2∼2.3%. These are caused by the fact maximum heat release period and main combustion period are getting short.

• Journal of the Korean Society of Combustion
• /
• v.22 no.4
• /
• pp.1-8
• /
• 2017

This study was conducted to evaluate the fire retardant performance of exfoliated graphite nanoplatelets (xGnP) applied for particleboard. This work measured heat release rate(HRR), total heat release(THR) and smoke production rate(SPR) of xGnP added particleboard, using cone calorimeter to assess its fire characteristics according to the KS F ISO 5660-1 standard code. Heat release rates of all specimens treated by xGnP were less than the $200kW/m^2$ for a total experiment period of five minutes. Heat release rates of the specimens coated with xGnP were lower than those of the specimens made by mixing wood particles with xGnP directly. Meanwhile, the total heat release rates of xGnP coated specimen maintained quite lower level than the uncoated so the xGnP coating were effective in improving the fire retardant performance of particleboard. However, the smoke emission peaking problem at the initial combustion period, which was caused by adding base coating materials, should be resolved for further satisfaction as a fire retardant materials.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.1
• /
• pp.153-161
• /
• 1993

Heat transfer processes in the combustion chamber of a pebble bed regenerative heat exchanger for MHD power generation has been analyzed numerically for heating, evacuation argon heating periods individually. The calculated result well explain the measured temperature change at the top of the pebble bed. The analytical result point out that the length of evacution period and the geometry optimization both for the combustion chamber and the heat storage bed are very important factors for the improvement of thermal performance in MHD power generation.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.3
• /
• pp.94-101
• /
• 2008

Since regulations of exhaust emissions are continuously reinforced, studies to reduce harmful emissions during the cold start period of SI engines have been carried out very extensively worldwide. During the cold start period, raising the temperature of cold exhaust gas is a key strategy to minimize the light-off time of three way catalysts. In this study, a synthetic gas containing a large amount of hydrogen was injected into the exhaust manifold to raise the exhaust gas temperature and to reduce harmful emissions. The authors tried to evaluate changes in exhaust gas temperature and harmful emissions through controlling the engine operating parameters such as ignition timings and lambda values. Also the authors investigated both combustion stability and reduction of harmful emissions. Experimental results showed that combustion of the synthetic gas in the exhaust manifold is a very effective way for solving the problems of harmful emissions and light-off time. The results also showed that the strategy of retarded ignition timings and increased air/fuel ratios with ESGI is effective in raising exhaust gas temperature and reducing harmful emissions. Futhermore, the results showed that engine operating parameters ought to be controlled to lambda = 1.2 and ignition timing = $0{\sim}3^{\circ}$ conditions to reduce harmful emissions effectively under stable combustion conditions.

• Journal of Acupuncture Research
• /
• v.21 no.3
• /
• pp.193-214
• /
• 2004

Objective : The purpose of this study is to investigate the mechanism and effect of moxibustion with ginger objectively, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxibustion with ginger. Methods : We have selected the indirect moxibustion with ginger among many indirect moxibustions. We produced a slice of ginger to a thickness of 3, 4, 5mm and the moxa cone having a diameter of 8mm, a height of 10mm for making a comparative study of characteristics of moxa cone according to change the density. We have made a comparative study of the thermodynamic characteristics of moxibustion with ginger with or without holes. We measured combustion times and calculated temperatures, temperature gradients in each period during a combustion of moxa. Results : 1. We found out it was not significantly influenced by the existence of the punched holes in a slice of ginger because the punched holes grow smaller immediately. 2. The duration of the preheating period became longer according to thickness of a slice of ginger and was not directly proportional to the density of moxa cone. The duration of the preheating period was extremely short when it burned a 100mg moxa cone. That was influenced by the density of moxa cone. 3. The duration of the heating period became longer according to thickness of a slice of ginger likewise the preheating period bacause the density of moxa cone had effected on the combustion characteristics. The duration of the heating period was extremely long when it burned a 100mg moxa cone. On the other hand the maximum temperature in the heating period was appeared that the combustion with a thin slice of ginger was highest and measured that the large density of moxa cone was higher. But the maximum temperature in the heating period was about $37.8^{\circ}C{\sim}44.2^{\circ}C$respectively lower in others. 4. The duration of the retaining period was some doubling shorter than that of the heating period that is concerned the shape of moxa cone. The temperature measured the close of a retaining period was $36.6^{\circ}C{\sim}41.8^{\circ}C$, that was considerably lower temperature. 5. The mean ascending temperature velocity and the mean descending temperature velocity were $0.042{\sim}0.073^{\circ}C/sec$, $-0.027{\sim}-0.064^{\circ}C/sec$ respectively. Then, the ascending temperature velocity was some faster than the ascending temperature velocity. Conclusions : The quantitative standard for obtaining the effective heating stimulation is that if the slice of ginger made a hole in it, we had to use the needle above 1.5mm diameter. The recommended size of a slice ginger is the 14mm diameter and the 2~3mm thickness. The moxa cone is formed the conical shape that the base diameter was 8mm, the height was 10mm, the density was $600mg/cm^2$.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.4
• /
• pp.56-62
• /
• 2008

A synthetic gas reformed from hydrocarbon-based fuels consists of $H_2$, CO and $N_2$. Hydrogen contained in the synthetic gas is a very useful species in chemical processes, due to its wide flammability range and fast burning speed. The ESGI (Exhaust Synthetic Gas Injection) technology is developed to shorten the light-off time of three way catalysts through combustion of the synthetic gas in the exhaust manifold during the cold start period of SI engines. Before the ESGI technology is applied to the test engine, the authors set a test rig that consists of gas temperature and composition controllers, an exhaust pulse generator and an exhaust manifold with a visualization window, in order to optimize the point and conditions of injection of the synthetic gas. Through measuring burned gas temperatures and taking photographs of synthetic gas combustion at the outlet of the exhaust manifold, the authors tried to find the optimal injection point and conditions. Analysis of burned gas composition has been performed for various $O_2$ concentrations. As a result, when the synthetic gas is injected at the port outlet of the cylinder No. 4 and $O_2$ concentration exceeds 4%, combustion of the synthetic gas is strong and effective in the exhaust manifold.

• Journal of Acupuncture Research
• /
• v.24 no.2
• /
• pp.155-167
• /
• 2007

Objectives : This study was performed to evaluate the general distribution and the efficacy of oriental medical treatment for low back pain. Methods: We have selected of the moxa bucket moxibustion. We make a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results : The 80 cases of low back pain patients was analyzed according to the distribution of sex, age, the period of disease, contributing factor, the patient-condition on admission, the symptom on admission, the duration of admission, the reading of the X-ray and the treatment efficacy was evaluated respectively. 1. Female was more than male in the ratio of 1:1.2, and thirties and seventies 25% the most, the acutest phase 46.3% the most, reason unknown 33.8% the most, Grade III 50% the most, L.B.P. only 51.3% the most, the day of 6-10 30% the most, compression Fx 30% the most. 2. In the total treatment result, the good was 51.3%, the excellent 22.5%, the fair 17.5%, the poor 8.8% in order. About 'the effective rate'(the percentage of positive effective treatment cases) of each distribution, the fifties 100% the most, the acutest phase 97.3% the most, the slip down, weight lifting, overuse 100% the most respectively, Grade III 97.5% the most, L.B.P. only 95.1% the most, the day of 11-15 100% the most, HN.P. 93.3% the most. Conclusions : We have known the efficacy of oriental medical treatment for L.B.P. was good and early treatment was better than late treatment and main cause of L.B.P. was degenerative change.