Earticle

In the steam turbine for combined cycle power generation operated for a long time, thermal and mechanical deformation is accumulated in the High-Intermediate Pressure (HIP) casing due to repeated start-up and stop under high temperature and high pressure conditions. This study attempted to quantitatively evaluate the deformation characteristics based on the measured data and analyze the effect of casing deformation on casing alignment and inner gap. To this end, the level of the horizontal split flange surface was precisely measured and analyzed for the two decomposed steam turbine high-pressure casing of the combined thermal power plants. As a result, Hogging deformation occurred throughout the casing, and a maximum strain deviation of 0.83mm between the upper and lower casings was confirmed, and an asymmetric deformation tendency was confirmed in which the upper part was more than twice as large as the lower part. Based on this phenomenon, by estimating the amount of centerline movement and the change in the inner gap that can occur during assembly due to the upper and lower deviation of the casing Hogging deformation, it was confirmed that Hogging deformation is a major influencing factor on casing alignment.

This study was aimed to improve the productivity and income of mushroom farming by developing a new casing material as a substitute for clay loam casing soil, which is becoming more difficult to acquire. When the new casing materials were used for the stable production of button mushroom (Agaricus bisporus), a 1:1 mixture of clay loam and button mushroom media obtained after harvest supported 13% greater mycelial growth (32.0 kg/3.3 m2). This material was better than clay loam soil in preventing contamination with environmental compounds and pests. The use of an inexpensive 1:1 mixture of peat moss and coco peat resulted superior mycelial growth with 4% better yield (32.9 kg/3.3 m2) compared with conventional clay loam soil. Advantages of these casing materials included ready availability and improved productivity. Mixtures of peat moss + coco peat + zeolite (50%:30%:20%) and coco peat + coal ash (75%:25%) could substitute for conventional casing soil. Additionally, the novel mixtures containing material obtained after cultivation might be used to produce organic fertilizer.

In this study, for the design of the impeller and volute casing shape of the water pump for flood prevention, performance was predicted through numerical analysis to secure the theoretical power and hydraulic efficiency of the front well at the discharge well 300m3/h, which is the target design specification, and the flow characteristics of each flow rate were checked and verified. Through the results of this flow analysis, it was possible to secure the basic shape design of the impeller and volute casing of the water pump for flood prevention. In the future, we will perform an interpretation to confirm structural safety according to shape and material.

As the importance of the indoor environment increases. As part of a study to improve range hood performance, a flow analysis of chamber casing was conducted. flow analysis was performed by applying Realizable () Model. For flow analysis, “STAR-CCM+” program of “SIEMENS” was used. It was analyzed how changes in inlet velocity, outlet velocity(flow rate) and static pressure increase occur according to changes in the shape of the chamber casing. Flow analysis was performed by changing the shape of the chamber casing limitedly, but the results were not helpful in improving the performance of range hood.

This study was conducted to set the proper sterilization standards of casing soil for the stable production of button mushroom(Agaricus bisporus) from mushroom disease that occurs in infection of casing soil material. Changes of aerobic bacteria are increased as the longer grow-out period and sharply increased after second flushes. Fluorescence Psuedomonas showed high density at high sterilization temperature and 100oC treatment has extremely high density at 30 min and 60 min in casing 22 days. Density of thermophilic actinomyces is sharply increase from casing with soil and the highest density at 22 days of casing and rapidly decrease after first flushes. Sterilizing temperature of casing soil affects quality and quantity of button mushroom. Treatment of 60 min, 90 min at 80oC and 30 min at 100oC produced the highest mushroom yields, especially mushrooms yields of A grads were the highest at treatment of 90 min at 80oC. Treatment of 60min at 100oC products many yields, however, this treatment has low economic feasibility for its yields. Sterilizing temperature of casing soil has an effect on generating diseases and insect pests. Treatment of 60 min, 90 min at 80oC and 30 min 100oC showed lower incidence than the other treatment. Although treatment of 30 min at 100oC causes low diseases and mushroom fly damage, it has low mushroom yields. Furthermore, although treatment of 60 min at 100oC has high mushroom yields, it causes high diseases and mushroom fly damage. Therefore the best conditions for the sterilization of casing soils was 60 min and 90 min at 80oC.

The paper designs and develops a casing cutting robot for the platform decommission. This robot can achieve the sea-bottom casing reclamation duties required by the environment protection acts related to decommissioning of offshore oil plants. The objective of this research work was to investigate and explore the casing cutting robot model for the platform decommission. A 2-linear axis cutting robot is prototyped and a test bench is designed in the laboratory for the research. A surface control system provides remote control functionalities for the operator to command signals and automatic sequences. The robot control system based on Programmable Multi-Axis Controller (PMAC), which makes it easier to be operated. Moreover a Human Machine Interface (HMI) is developed to monitor and control the cutting process conveniently. The laboratory test results show that the robot system developed is very usable and it is working satisfactory for the casing cutting.

The effectiveness of a submarine casing cutting robot is mainly influenced not only by its operational but also by its reliability and safety. In this paper, fault diagnosis research of this cutting robot is evaluated using the Bayesian network. A methodology of transforming the fault tree model into Bayesian network model is used. The fault tree model is established simply and conveniently. Bayesian network can address interesting questions allowing both forward and backward analysis. Combining the merits of two methods, the causes of failures, the occurrence probabilities and the importance of various components are analyzed based on the Netica software. The results show that the robot has high reliability and should be paid attentions to the research of feeding mechanism and the discharge gap detection circuits.

With the development of drilling technology and the needs of the larger Bulit-up, the screw drill with larger structure corner is used more widely in drilling field. Because the existence of single curved screw drill tool with larger structure corner, it have larger friction during the bend PDM in the process of internal casing, so we often need to use the wellhead adjuvant into the well. In order to understand the single bent screw drill into the state in the wellhead diameter of casing, and how the angle of screw structure impact the feasibility, This paper analysis the stress of the single curved screw drilling tools in the well, and the condition it can safely through the mouth of the well conditions, establish the single bend PDM in the calculation wellhead down model. and the finite element model is established combined with the specific parameters of a well which is in the western of SiChuan depression. Using ansys analysis a particular casing inside diameter, under wellhead vertical segment into different structure when the turn of the screw drilling tools down into characteristics and stress distribution characteristics, it is concluded how large of the structure corners and how depth that the bend PDM can rely on gravity well down into the inside diameter of 250.19 mm casing, concluded the relationship between reaction force, friction force, and maximum stress with the well depth and the change of structure corners from 1.5°to 2.75°，provide a basis for drilling site selection of the appropriate combinations of screw drill and how to regulate the radial force of the device while into the well.

Construction equipment noise has caused much annoyance for a number of dwellers in nearby construction field and has become a very serious issure in our living environment. Therefore, in our country, a practical solution and a better method of reducing construction equipment noise are highly required in construction field. Practical solutions for the construction equipment noise, however, are very difficult because of the poorness of basic data and insufficiency of the existing research. Especially, in order to establish the sound insulation plan about pilling works noise with high sound pressure level and impactive, a real situation of sound characteristics about the noise of pilling works in foundation work demands more detail investigation. In this point, this study attempts to survey the characteristics of attenuation and propagation of construction equipment noise in pilling work using SIP(soil-cement injected precast pile) method with casing. And this study intends to get the basic data for establishment of a standard about construction noise.

The hot gas casing of gas turbine has operated high temperature and thermal gradient. The structure safety of hot gas casing will be highly depend on the thermal stress. In this paper, flow and thermal stress analysis of hot gas casing is carried out using ANSYS program. The obtained temperature data by flow analysis of hot gas casing apply the load condition of the thermal analysis. The thermal stress analysis is carry out the elastic-plasticity analysis. The pressure, temperature and velocity of the flow and thermal stress of the hot gas casing are presented.

This paper presents the vibration problem of the Engine Casing (E/C) "B" deck in the handymax vessel and describes a method to avoid resonance. The first ship of the series did not have any vibration issue on the "B" deck. However, resonance condition occurred when additional machine was installed to the following vessels. To understand the dynamic characteristics of the deck, the normal mode analysis and impact test have been performed. Within the normal operating range of the vessel, the $1^{st}$ natural frequency of the E/C "B" deck is close to the main engine's $6^{th}$ order. Based on these analysis, a reinforcement on the deck was suggested and it proved to be effective. Since actual impact test after the reinforcement also confirmed the resonance avoidance.

The primary design goal of a compressor is focused on improving efficiency. Secondary objective is to widen the operating range of compressor. This paper presents a numerical and experimental investigation of the influence of the bleed slot on the operating range for the 1.2 MW class centrifugal compressor installed in a turbocharger. The main design parameters of the bleed slot casing are upstream slot position, inlet pipe slope, downstream slot position and width. The DOE(design of experiment) method was carried out to optimize the casing design. Numerical analyses were done by the commercial code ANSYS-CFX based on the three dimensional Reynolds-averaged Navier-Stokes equations. Results showed that efficiency and pressure ratio increased as the downstream slot position and width were smaller and the upstream position was located away from the impeller inlet. Experimental works were also done with and without the bleed slot casing. The simulation results were in good agreement with the test data. Enhancement of both the surge margin up to 26.5% and the pressure ratio with the optimized bleed slot design were achieved, compared with the surge margin of only 6.6% without the bleed slot casing.

이 글에서는 터빈 Casing Bolt 분해조립 시 신기술 가열분해 공법을 적용하여, 정비기간 단축 및 Bolt 파손을 방지한 사례에 대해 소개하고자 한다.

Nowadays, computational fluid dynamics is commonly used by design engineers to evaluate and compare losses in hydraulic components as it is less expensive and less time consuming than model tests. For that purpose, an automatic tool for casing and distributor analysis will be presented in this paper. An in-house mesh generator and a Reynolds Averaged Navier-Stokes equation solver using the standard $k-{\omega}$ shear stress transport (SST) turbulence model will be used to perform all computations. Two solvers based on the C++ OpenFOAM library will be used and compared to a commercial solver. The performance of the new fully coupled block solver developed by the University of Lucerne and Andritz will be compared to the standard 1.6ext segregated simpleFoam solver and to a commercial solver. In this study, relative comparisons of different geometries of casing and distributor will be performed. The present study is thus aimed at validating the block solver and the tool chain and providing design engineers with a faster and more reliable analysis tool that can be integrated into their design process.

Collagen casing에 충진한 명란훈연제품의 품질특성은 다음과 같다. 대조구 및 set 제품에서 carrageenan의 첨가량이 많을수록, 전분의 양이 적을수록 texture(hardness and gumminess) 및 관능적(taste 및 acceptability) 특성이 높게 측정되었고, 명란훈연제품 제조 시 setting은 gumminess 강도를 크게 증가하였다. Set 제품에 있어서 조미성분의 최적 배합비율은 roe, starch 및 carrageenan을 각각 88.50, 5.00 및 2.00으로 배합한 제품이 경제적 측면에서 양호한 것으로 생각되며, 진공 및 질소포장에 따른 저장기간 중의 품질변화는 다음과 같다. 모든 시료에서 pH는 저장 4개월째까지 증가 하였다가 감소였으며, 일반포장 제품이 진공 및 질소포장에 비하여 pH 변화가 높았다. 휘발성 염기성질소량 및 TBA 값은 일반포장을 한 제품에서는 저장기간이 증가할수록 증가하였으며, 진공 및 질소포장 제품은 저장 2개월째까지는 변화가 없다가 저장 4개월째부터 저장기간이 증가할수록 증가하였다. 총균수는 일반포장 제품이 진공 및 질소포장에 비하여 저장기간 동안에 높은 수치를 나타내었으며, 대장균군은 모든 시료에서 저장기간 동안에 음성으로 측정되었다. Collagen casing에 충진한 명란훈연제품의 품질은 cellulose casing에 충진한 제품과 저장 중 뚜렷한 품질차이가 없었으며, Wienner sausage와 같이 소규모 훈연제품의 생산에 적합하다고 판단된다. 그러므로 명란훈연제품은 새로운 형태의 수산가공식품으로 건강지향적인 소비자들의 기호에 적합하므로 산업화 가능성이 높은 제품이라고 판단된다.

Alaska pollock roe is mainly used as a raw material for fermented seafood, especially in the East Asia. Kernels of Alaska pollock roe are not valuable as a raw material and usually discarded as a waste product. In order to utilize the broken roes of Alaska pollock, the smoked product, a imitated sausage, was manufactured for commercial production. Texture intensity (hardness and gumminess) and sensory evaluation (taste and acceptability) of the smoked Alaska pollock roe packed with collagen casing were evaluated based on mixture design and regression models. At higher concentration of carrageenan and lower concentration of starch in the formula of the smoked Alaska pollock roe, higher texture intensity and sensory scores were obtained. pH values of all treatments (control, vacuum and $N_2$ packages) increased up to 6.28, 6.23 and 6.24 on 4 months of storage, respectively, and then decreased. The numbers of VBN, TBA and viable cell counts increased during storage periods, higher in control than in vacuum and $N_2$ packages. Coliform bacteria was not detected in all treatment during storage periods.

Various bacteria were isolated from the casing layer soil of the culture bed of P. ostreatus and their role in fruiting body induction of the edible mushroom, P. ostreatus, was investigated. Analysis of the bacterial community isolated from the casing layer soil revealed that the composition of genera and number of cultivable bacteria were different for each sterilizing treatment. Bordetella was predominant in the bulk soil whereas Flavobacterium was predominant after sterilization of the casing layer soil. Fluorescent Pseudomonas was predominant in the non-sterilized casing layer soil. Total number of the bacterial genera in the casing layer soil was higher than that in the bulk soil. In particular, an increase in the fluorescent Pseudomonas population was observed in the non-sterilized casing layer accompanied by induction of fruiting body and enhanced mushroom production yield. The results suggested that specific bacterial populations in the casing layer play an important role in the formation of primodia and the development of basidiome in P. ostreatus.

The effects of casing shapes on the performance and the interaction between an impeller and a casing in a small-sized centrifugal compressor are investigated. Especially, numerical analyses are conducted for the centrifugal compressor with both a circular casing and a volute one. The optimum design for each element (i.e., impeller, diffuser and casing) is important to develop an efficient and compact compressor using alternative refrigerant as working fluids. Typical rotating speed of the compressor is in the range of 40,000∼45,000 rpm. The impeller has backswept blades due to tip clearance and a vane diffuser has wedge type. In order to predict the flow pattern inside an entire impeller, vaneless diffuser and casing, calculations with multiple frames of reference method between the rotating and stationery parts of the domain are carried out. For computations of compressible turbulent flow fields, the continuity and time-averaged Navier-Stokes equations are employed. To evaluate the performance of two types of casings, the static pressure recovery and loss coefficients are obtained for various flow rates. Also, static pressure distributions around casings are studied for different casing shapes, which are very important to predict the distribution of radial load. The static pressure around the casing and pressure difference between the inlet and outlet of the compressor are measured for the circular casing.