Steel is the mother of industry, and is also an energy consumption intensive industry. Since the energy crisis, the various countries iron and steel plants positively take each energy frugal measure in order to reduce the fuel and the electric power consumption. In the iron and steel plant comparatively consumes the energy the system regulation equipment is the reheating furnace, so to save energy in a reheating furnace and reduce the energy consumption become one of important topics. The reduction consumes energy the countermeasure aspect may by analyze the heat transfer model and the change reheating furnace characteristic begins. In this thesis, we will build a simulation system of reheating furnace to analysis the temperature change of slab in a reheating furnace and discussion energy consumption factor. And then we use the thermal balance model to analysis the situation of fuel consumption. According to different conditions, we want to discuss the relationships energy consumption and increasing temperature of slab inside furnace.

Abstract Steel is the mother of industry, and is also an energy consumption intensive industry. Especially for the rolling mill, the energy consumption in a reheating furnace take a half, so to save energy in a reheating furnace and reduce the energy consumption become the major issue in the future. The reheating furnace used in general process of steel producing can divided into two types-Continuous type and Batch type- through its ability of steel rolling¡Napproach and its demand. In this thesis, our research target is the batch type reheating furnace, we based on theory of heat transfer in a reheating furnace to build a simulation system of reheating furnace and calculate the temperature-time curve of slab and its heat flux. And then we use the thermal balance model to analysis the situation of fuel consumption. According to different operated conditions, we want to discuss the relationships between energy consumption and increasing temperature of slab inside furnace¡Nsoaking degree¡C From analysis result, we can find that fixed the total time in furnace, the longer of heating time is, the lower of average temperature of slab and the higher of temperature difference of discharge slab are. But in the process of increasing temperature, the max temperature difference of slab is lower. Using the exhaust gas to preheat air through the heat exchanger, we can find that when the temperature of preheated air is increasing, the heat loss of exhaust gas and fuel consumption will be lower. When air-fuel ratio is getting higher, the temperature difference in the process of increasing temperature will be getting lower, and it will be higher as the slab soaks. When air-fuel ratio is increasing, the quantity of fuel consumption will increase too. In respect of refractory material, heat loss of furnace and accumulation of heat in refractory material caused by using the refractory cottons is less than using the refractory bricks. Besides that, the different fuel will only affect the quantity of fuel consumption, not increasing temperature of slab and soaking degree.

Grain storage is an essential part of the food production chain. Therefore, pre- venting grain deterioration is a key issue in a grain storage system. There are several causes for spoilage, all resulting in grain quality and quantity loss. One approach to detect incipient spoilage is by detecting the produced volatiles. In the past, many sensors for detecting volatiles have been developed and are used in industry. However, most of the commercial gas sensors are bulky with high power consumption, mainly limited in range of operating temperature, or require a restricted control over temperature and humidity. This thesis describes the design, fabrication and evaluation of a gas sensor capable of detecting volatiles and considers the potential use of polymer- based sensors. Conductive polymer-based sensors have been reported sensitive to a wide range of volatiles but are commonly evaluated under a controlled environment. Conventional sensor reproducibility and repeatability are also a concern due to the difficulties associated with polymer composite film preparation. In addition, current studies have not fully explored sensor properties in response to humidity, a common factor in any environment, and a variable parameter in grain storage facilities. Moreover, these sensors suffer from ambient temperature dependency as they work based on partitioning mechanism. To enhance sensor performances and eliminate the temperature dependency, a new sensor structure is proposed. The new design uses standard lithography process to fabricate a thermally isolated cantilever containing interdigitated electrodes and a micro-heater to efficiently heat and maintain a constant temperature throughout the interdigitated electrodes. This structure eliminates sensor response drifts caused by ambient temperature variations. Capacitive measurements are performed as the means of volatile detection, which simplify the use of polymers due to the absence of conductive filler and the challenges associated with it. Frequency spectroscopy provides additional information regarding the presence of volatiles compared to conventional resistive sensors, since mechanisms other than swelling are involved. Moreover, frequency and temperature modulations can be employed to further enhance sensor performance, enabling the use of a reduced number of sensors in a sensor array.

Grain storage is an essential part of the food production chain. Therefore, pre- venting grain deterioration is a key issue in a grain storage system. There are several causes for spoilage, all resulting in grain quality and quantity loss. One approach to detect incipient spoilage is by detecting the produced volatiles. In the past, many sensors for detecting volatiles have been developed and are used in industry. However, most of the commercial gas sensors are bulky with high power consumption, mainly limited in range of operating temperature, or require a restricted control over temperature and humidity. This thesis describes the design, fabrication and evaluation of a gas sensor capable of detecting volatiles and considers the potential use of polymer- based sensors. Conductive polymer-based sensors have been reported sensitive to a wide range of volatiles but are commonly evaluated under a controlled environment. Conventional sensor reproducibility and repeatability are also a concern due to the difficulties associated with polymer composite film preparation. In addition, current studies have not fully explored sensor properties in response to humidity, a common factor in any environment, and a variable parameter in grain storage facilities. Moreover, these sensors suffer from ambient temperature dependency as they work based on partitioning mechanism. To enhance sensor performances and eliminate the temperature dependency, a new sensor structure is proposed. The new design uses standard lithography process to fabricate a thermally isolated cantilever containing interdigitated electrodes and a micro-heater to efficiently heat and maintain a constant temperature throughout the interdigitated electrodes. This structure eliminates sensor response drifts caused by ambient temperature variations. Capacitive measurements are performed as the means of volatile detection, which simplify the use of polymers due to the absence of conductive filler and the challenges associated with it. Frequency spectroscopy provides additional information regarding the presence of volatiles compared to conventional resistive sensors, since mechanisms other than swelling are involved. Moreover, frequency and temperature modulations can be employed to further enhance sensor performance, enabling the use of a reduced number of sensors in a sensor array.

In our study, the Finite Volume Method (FVM) is successfully implemented to simulate thermal process of polymerization. This application is verified based on the obtained plots compared with those from other two methods as well as experimental data. After the verification, a method is developed to optimize heat history in order to reduce processing time and in the meantime to maintain the uniformity of cure state. Also sensitivities of cure state to different parameters are examined. Besides, a correlation between temperature and the degree of polymerization profile on sample surface is found using on-line monitoring method.

In this research a state-of-the-art micro-thermal conductivity detector is developed based on MEMS technology. Its efficient design include a miniaturized 100×2 µm bridge from doped polysilicon, suspended 10 µm away from the single crystalline silicon substrate through a thermally grown silicon dioxide sacrificial layer. The microbridge is covered by 200 nm silicon nitride layer to provide more life time. Analytical models were developed that describe the relationship between the sensor response and ambient gas material properties. To obtain local temperature distribution and accurate predictions of the sensor response, a computational three dimensional simulation based on real geometry and minimal simplifications was prepared. It was able to handle steady-state and transient state, include multiple physics such as flow, heat transfer, electrical current and thermal stresses. Two new methods of measurement for micro TCD were developed; a time resolved method based on transient response of the detector to a step current pulse was introduced that correlates time constant of the response to the concentration of gas mixture. The other method is based on AC excitation of the micro detector; the amplitude and phase of the third harmonic of the resulting output signal is related to gas composition. Finally, the developed micro-sensor was packaged and tested in a GC system and was compared against conventional and complex FID for the detection of a mixture of VOCs. Moreover compact electronics and telemetry modules were developed that allow for highly portable applications including microGC utilization in the field.