28 Steam drum outlet steam temperature

2021 ◽  
pp. 99-105
Keyword(s):  
2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Cuihui Shen ◽  
Yamin Zhao ◽  
Yiqun Li

Nowadays, our life needs more and more electricity, and our lives cannot be without electricity, which requires our power to develop more quickly. Power plants are undoubtedly the place where electricity is produced. And now most of the power plant or chemical energy can be converted into heat, and then through the heat to do power production. The boiler is the main part of the power plant. Boiler unit consists of boiler body equipment and auxiliary equipment. The main body of the boiler consists of 'pot' (soft drinks system) and 'furnace' (combustion system). Baotou thermal power plant is mainly burning gas. The gas and air are at a certain rate into the furnace burning. This can greatly reduce the pollution of the environment, but also the full use of fuel. The soda system is mainly carried out in the drum. The heat generated by the combustion system heats the water in the drum, producing steam and then pushing the steam turbine into mechanical energy and finally into electrical energy. This has a high demand for water level, water composition, and the temperature of the steam produced in the drum. The water level should have upper and lower bounds, keeping it within a certain range. Water level is too high, will affect the steam drum soda separation effect, so that the steam drum exports of saturated steam with water increased, causing damage to the turbine, will cause serious explosion. And the water level is too low, it will affect the natural circulation of the normal, serious will make the individual water pipe to form a free water, resulting in flow stagnation, resulting in local metal wall overheating and burst pipe. Water in the heating at the same time will form a lot of scale, if not the chemical treatment of water will be in the formation of scale in the drum, cleaning more difficult, so the damage to the drum. The pressure of the drum is also an important control variable, and pressure control is highly correlated with liquid level control. It is necessary to ensure the integrity of the equipment, but also to ensure safety, followed by ensuring that the process of normal operation of the drum water. This time, the design is mainly for the unit steam temperature control system design. Steam temperature is one of the important indicators of boiler operation quality. It is too high and too low will significantly affect the power plant safety and economy. If the temperature of the steam is low, it will cause the power plant to increase the heat consumption and increase the axial thrust of the turbine to cause the thrust bearing to overload, but also cause the steam turbine to increase the final steam humidity, thus reducing the efficiency of the turbine, aggravating the erosion of the blade. On the contrary, the steam temperature is too high will make the super-heater wall metal strength decreased, and even burn the high temperature of the super-heater, the steam pipe and steam turbine high-pressure part will be damaged, seriously affecting safety. The boiler temperature control system mainly includes the adjustment of the superheated steam and the reheat steam temperature. The superheated steam temperature is the highest temperature in the boiler soda system. The stability of the steam temperature is very important for the safe and economical operation of the unit. Therefore, in the boiler operation, must ensure that the steam temperature in the vicinity of the specified value, and the temperature of the super-heater tube wall does not exceed the allowable working temperature.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 607-618
Author(s):  
JÉSSICA MOREIRA ◽  
BRUNO LACERDA DE OLIVEIRA CAMPOS ◽  
ESLY FERREIRA DA COSTA JUNIOR ◽  
ANDRÉA OLIVEIRA SOUZA DA COSTA

The multiple effect evaporator (MEE) is an energy intensive step in the kraft pulping process. The exergetic analysis can be useful for locating irreversibilities in the process and pointing out which equipment is less efficient, and it could also be the object of optimization studies. In the present work, each evaporator of a real kraft system has been individually described using mass balance and thermodynamics principles (the first and the second laws). Real data from a kraft MEE were collected from a Brazilian plant and were used for the estimation of heat transfer coefficients in a nonlinear optimization problem, as well as for the validation of the model. An exergetic analysis was made for each effect individually, which resulted in effects 1A and 1B being the least efficient, and therefore having the greatest potential for improvement. A sensibility analysis was also performed, showing that steam temperature and liquor input flow rate are sensible parameters.


2019 ◽  
Author(s):  
Wan-Ting (Grace) Chen ◽  
Zhenwei Wu ◽  
Buchun Si ◽  
Yuanhui Zhang

This study aims to produce renewable diesel and biopriviliged chemicals from microalgae that can thrive in wastewater environment. <i>Spirulina</i> (SP) was converted into biocrude oil at 300ºC for a 30-minute reaction time via hydrothermal liquefaction (HTL). Next, fractional distillation was used to separate SP-derived biocrude oil into different distillates. It was found that 62% of the viscous SP-derived biocrude oil can be separated into liquids at about 270ºC (steam temperature of the distillation). Physicochemical characterizations, including density, viscosity, acidity, elemental compositions, higher heating values and chemical compositions, were carried out with the distillates separated from SP-derived biocrude oil. These analyses showed that 15% distillates could be used as renewable diesel because they have similar heating values (43-46 MJ/kg) and carbon numbers (ranging from C8 to C18) to petroleum diesel. The Van Krevelan diagram of the distillates suggests that deoxygenation was effectively achieved by fractional distillation. In addition, GC-MS analysis indicates that some distillates contain biopriviliged chemicals like aromatics, phenols and fatty nitriles that can be used as commodity chemicals. An algal biorefinery roadmap was proposed based on the analyses of different distillates from the SP-derived biocrude oil. Finally, the fuel specification analysis was conducted with the drop-in renewable diesel, which was prepared with 10 vol.% (HTL10) distillates and 90 vol.% petroleum diesel. According to the fuel specification analysis, HTL10 exhibited a qualified lubricity (<520 µm), acidity (<0.3 mg KOH/g) and oxidation stability (>6 hr), as well as a comparable net heat of combustion (1% lower), ash content (29% lower) and viscosity (17% lower) to those of petroleum diesel. Ultimately, it is expected that this study can provide insights for potential application of algal biocrude oil converted via HTL.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Dadik Pantaya., dkk

The present study was conducted to clarify the effect of addition of enzymes from rumen liquor on performance broiler of pelleting feed with basal ration of wheat pollard with addition of enzymes and processing broiler diets. Ruminal enzymes were extracted from Australian Commercial Cross (ACC) cattles. Application of enzyme on wheat pollard. Enzyme was reacted with wheatpollard and mixed with another feedstuff before steam pelleting process. The combination nine experimental diets were used as follows three levels enzyme supplementation (0, 620 and 1.240 U/kg) and three levels steam temperature at (60, 80 and 100 oC) Feed particles size, hardness, PDI (Pellet Durability Index), moisture content, protein, GE and hemicellulosa were evaluated parameter devided into nine treatmens were used in this research. Data from Completely Randomized Design factorial 3 x 3 were analyzed with Anova, if differences were continued by Duncan’s new multiple range test. Enzyme supplementation decreased feed hardness and PDI. There were interaction beetwen enzyme and temperature for feed moisture content. Hemicellulosa was significantly reduced by steam temperature at 80 and 100 oC and enzyme supplementation 1.240 U/kgKey Words: enzyme liquor rumen, wheat pollard, steam pelleting, feed Chemical composition


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