State-of-the-art/Literature Review

Discuss About The Numerical Approach Prediction Of Particulate.

A boiler is nothing but a vessel which is closed and in this the fluid mainly the water is heated. It is not necessary that the fluid would be boiling. Once the fluids are heated up then the fluids which has been vaporized would be exiting the boilers which is generally used for various processes of by the heated applications and this includes the heating of the water, generation of power, cooking, central heating and many more. Fouling is generally considered to be the deposition that is taking place over the convention heat surfaces. Fouling can be defined as the deposition of the materials which are unwanted upon the solid surfaces so as to reduce the functioning of a boiler (Dai et al. 2015). This type of fouling materials might be living as well as non-living that is inorganic or organic substance. This type of phenomenon is generally differentiated from the other surface deposition phenomenon. Vaporization of the volatile inorganic elements while the coal is brunt and this act as the main reason for the fouling.

According to Hocker et management. the dye penetration has been associated with indicating the effects on the zones which were affected by the heat of the 2014- T6 aluminum weldments. This has been associated with causing a lot of rejections related to the production assemblies. Along with this an investigated has also been associated with revealing the fact that the major portion of the defects which were indicated were superficially in such a way that the amount is always less than 0.007 deep (Hocker and Wilson 2014). Along with this several tests were also conducted so as to determine the cause and the nature of the defects occurring on the surface.  The procedures were also developed so as to eliminate or to minimize the occurrence of the indications related to dry penetration and also for the purpose of discriminating between the effects related to real weld and the defects related to superficial surface. For the purpose of repairing the weldments which contains the dye penetration indications various type of procedures were also developed.

Yahia et al. has been associated with discussing the fact that the radiography is generally considered to be a fact which is associated with evaluating and control that is non-destructive. Besides this they have also been associated with providing relevance of the various kind of radiographic inspections adopted by various kind of industries and along with this there also exists various research projects which are generally aimed at automating the process of analysis and the discontinuities that occurs in the interpretation of the welding (Muhaisen and Hokoma, 2012). In their work they have been associated with making of the automatic control and the inspection of the defects in the welding. This has been done by using the edge detection method of the radiographic images and is generally dependent upon the usage of the Multilayer Perceptron or the MPC. This paper has also been associated with providing the definition of the original method which is related to the detection of the defects present in the radiography and is generally dependent upon the usage of the neural networks which are artificial in nature along with aiming in the classification and also the recognition of the default percentage is increased in a successful way. The work done by them has been divided into four steps and this mainly includes the following: The first step mainly includes the preparation of the database which is to be utilized later in order to provide training to the MPC in the second step. Followed by this step comes the third step which has been classified into two sections the first part is totally devoted for the purpose of detecting the contours, and after this the second section mainly includes the elimination of contours which are additional (Wac?awiak and Kalisz 2012).

Research Question, Aim/Objectives and Sub-goals

The paper by Samaras et al has been associated with presenting the simulation and optimization of the results which were obtained from the 300 MW lignite-fired power plant. For the purpose of reducing the time needed for computation there is need of creating a module in the gPROMS FO in order to calculate the properties related to thermodynamics and the heat transfer that the fluids are having is also very much important. Reduction of the variables from the 375,630 to 10,906 has been done by making use of the FOs, besides this they have also been associated with reducing the number of the parameters present in the model as well (Tzolakis et al. 2012).  After the completion of the simulation in a successful way they have been associated with optimizing the operations in the plant so as to have improvements in the efficiency along with maintaining the reduction in the electric power.  The results have been associated with showing an absolute rate of improvement of around 0.55% in the overall thermal efficiency, and along with this it has been seen that they are having an important effect upon the plants as the resulting benefits included the lower consumption of the fuel and the lower emission of the fuel gas.  Besides this the results due to reduction also has a lower penalty fee related to pollutions in the environment. It is considered that this would be leading to the formation of decision tool which might be used by the control room of the unit (Chen et al. 2012). The model would be working by making use of the real time data which would be associated with allowing the engineers to make instant decision.

The experiential setup would be designed in order to determine the efficiency that a boiler is having and also for the purpose of determining the various effects due to different kind of factors.

Heating of the water is generally done by the energy that is released by the process of combustion.

The research questions associated with the conducting of this experiment has been listed below:

Q1. What the major reasons responsible for affecting the efficiency?

Q2. How the efficiency of the system can be increased?

Q3. What the possible errors that might occurs?

Q4. What are the ways of eliminating the error?

Q5. How are the calculations to be made?

The efficiency that the boiler is having is generally considered to be the ration of the useful heat that is taken by the water (Q_W­) in order to avail the heat present in the fuel (Q_R).

Theoretical Content/Methodology

Equtaion 1

The units efficiency would be affceted during the experiment and this is mainly due to the combution which is incomplet(Q_i), loss of heat from the exhaust (Q_e) and lastly the loss of heat from the environemnt (Q¥). In order to check the quantities which is measured there is a need of balancing the heat (Baxter and DeSollar 2013).

Equation 2

The heat that is available in the fuel (Q_f) can be identified from the complete combustion process and this is done by writing the balance equation of the fuel.

Equation 3

h°f ­ is generally considered to be enthalpy for the formation of the substances (kj/kg) which is generally done at a temperature of T⁰, 298K.

The fuel consumption is generally determined by making use of the results obtained from analyzing the gas.

The heat that is obtained by the water is generally obtained from the measurements done on water and also on the ambient conditions.

In order to calculate the loss of heat occurring in the chamber associated with combustion which preset in the boiler towards the surrounding is Q¥. This is associated with usage of the heat transfer method.

Equation 4

In this the h is generally considered to the conventional heat transfer coefficient where h=25 W/m­²K, the surrounding temperature is the T¥. The area A is generally obtained from the S and the L, where S is considered to be the parameter of the combustion chamber which is around 163cm whereas the L is considered to be the length that the combustion chamber is having which is around 97 cm. T(x) is generally considered to be the temperature at the x location of the boiler.

It is also possible to find the heat loss from the exhaust and this can be done by the equation provided below:

Equation 5

It is also possible to calculate the effects that the incomplete combustion is having from the equation provided below:

Equation 6

Lastly the efficiency of the boiler can be estimated by making use of the eqation provided below:

This unit would be associated with igniting and allowing the achievement of the steady state condition by having the correct ratio of air and fuel. Besides this the flow of the water is to be adjusted in order to provide a high outlet temperature by having a temperature of around 80⁰C. Along with this an extra care is to be taken by having a constant observation over the entire experiment. During the measurements of the steady condition are generally taken of everything which is generally associated with the process of contributing towards the gain or loss of the heat taking place in the system and these mainly includes the rate of flow and the temperature, heating of the cold water, temperature of the fuel gas and the composition they are having and lastly the loss of heat taking place towards the environment from the surface of the unit. Besides this it is also compulsory to measure the temperature of the fuel gas by making use of devices like the suction pyrometer. Besides this it is possible to estimate the losses taking place from the Unit surface as well. The gas flow analyzer would be used for the purpose of determining the composition of the gas that is coming from the exhaust.

After the completion of the experiment it is possible to evaluate the isentropic efficiency from the values that are measured from the experiment. After the management of the experiment is completed then there is a need of plotting a graph of the air/mass ratio vs the efficiency. All the calculations ate conducted in order to have a clear result and also to show the estimations that has been made. The results are then shown in a tabulated format. After the completion of the experiment it is possible to identify the causes responsible for the various kind of errors that are made in the experiment. After this a detailed error analysis is to be made.

Fig 1: Gantt Chart

(Source: Created by Author)

Conclusions

The experiment helps in concluding to the fact that it is associated with providing a lot of gain as well as loss in the amount of heat along with providing the ways of heating up of the cold water, the temperature that the gas is having which is used for fueling the system and many more. Measurement of the temperature can also be done by identification of the various kind of equipment’s and besides this it is also possible to estimate the heat loss as well. The composition that the fueling gas and the emitted gas is having can also be easily determined by use of this experiment.

References

Baxter, L. and DeSollar, R. eds., 2013. Applications of advanced technology to ash-related problems in boilers. Springer Science & Business Media.

Chen, Q., Finney, K., Li, H., Zhang, X., Zhou, J., Sharifi, V. and Swithenbank, J., 2012. Condensing boiler applications in the process industry. Applied Energy, 89(1), pp.30-36.

Dai, B.Q., Wu, X., De Girolamo, A. and Zhang, L., 2015. Inhibition of lignite ash slagging and fouling upon the use of a silica-based additive in an industrial pulverised coal-fired boiler. Part 1. Changes on the properties of ash deposits along the furnace. Fuel, 139, pp.720-732.

Li, J., Brzdekiewicz, A., Yang, W. and Blasiak, W., 2012. Co-firing based on biomass torrefaction in a pulverized coal boiler with aim of 100% fuel switching. Applied Energy, 99, pp.344-354.

Low, F., De Girolamo, A., Wu, X., Dai, B. and Zhang, L., 2015. Inhibition of lignite ash slagging and fouling upon the use of a silica-based additive in an industrial pulverised coal-fired boiler: Part 3–Partitioning of trace elements. Fuel, 139, pp.746-756.

Luan, C., You, C. and Zhang, D., 2014. An experimental investigation into the characteristics and deposition mechanism of high-viscosity coal ash. Fuel, 119, pp.14-20.

Muhaisen, N.A.R. and Hokoma, R.A., 2012. Calculating the Efficiency of Steam Boilers Based on Its Most Effecting Factors: A Case Study. WorldAcademy of Science, Engeneering and Technology, 6.

Pan, Y., Si, F., Xu, Z., Romero, C.E., Qiao, Z. and Ye, Y., 2012. DEM simulation and fractal analysis of particulate fouling on coal-fired utility boilers’ heating surfaces. Powder technology, 231, pp.70-76.

Panagiotidis, I., Vafiadis, K., Tourlidakis, A. and Tomboulides, A., 2015. Study of slagging and fouling mechanisms in a lignite-fired power plant. Applied Thermal Engineering, 74, pp.156-164.

Patiño, D., Crespo, B., Porteiro, J. and Míguez, J.L., 2016. Experimental analysis of fouling rates in two small-scale domestic boilers. Applied Thermal Civil Engineering, 100, pp.849-860.

Pérez, M.G., Vakkilainen, E. and Hyppänen, T., 2016. Fouling growth modeling of kraft recovery boiler fume ash deposits with dynamic meshes and a mechanistic sticking approach. Fuel, 185, pp.872-885.

Stam, A.F., Haasnoot, K. and Brem, G., 2014. Superheater fouling in a BFB boiler firing wood-based fuel blends. Fuel, 135, pp.322-331.

Tzolakis, G., Papanikolaou, P., Kolokotronis, D., Samaras, N., Tourlidakis, A. and Tomboulides, A., 2012. Simulation of a coal-fired power plant using mathematical programming algorithms in order to optimize its efficiency. Applied Thermal Engineering, 48, pp.256-267.Hocker, R.G. and Wilson, K.R., 2014. Dye Penetrant Indications Caused by Superficial Surface Defects in 2014 Aluminum Alloy Welds. Weld. J, pp.50-11.

Wac?awiak, K. and Kalisz, S., 2012. A practical numerical approach for prediction of particulate fouling in PC boilers. Fuel, 97, pp.38-48.

Yang, Z.C., LIU, J.L. and Yao, W., 2013. Fouling index of Zhundong coal ash. Clean Coal Technology, 2, pp.81-84.