3 research outputs found
Modeling of Coal Spontaneous Fire in A Large-Scale Stockpile
The increasing need for energy consumption has
resulted in the use of energy sources in coal continuing to increase. The
transportation and distribution activities of coal also cause the pile to be
exposed to heat when it is in a pile. Due to the kinetic characteristics of
low-rank coal, the pile is very susceptible to spontaneous fire processes. Of
course, this spontaneous fire phenomenon harms the safety and economic aspects
of the coal pile. This study aims to model finite elements using Multiphysics simulation
to determine the effect of the relative humidity of the pile on the temperature
distribution of large-scale coal piles. Thus, handling methods and things that
must be considered in storing and transporting coal piles can be formulated.
Thermal phenomena modelling in coal piles is modeled using COMSOL Multiphysics
software. The simulation is carried out by varying relative humidity of the
environmental conditions (ambient). The simulation results show that this
parameter can change the level of vulnerability of the pile to burn at an
earlier time
Effect of the Heat Transfer Surface on Prevention of Spontaneous Combustion of Coal
The increased use of coal for power
generation has increased the demand for low-rank coal, such as lignite and
sub-bituminous coal, and during its supply, it may need to be stored for long
periods. Because low-quality coal is more susceptible to spontaneous combustion
than high-quality coal, its storage could potentially cause work-related
accidents. One method being developed to control the temperature of stored coal
to prevent spontaneous combustion is the immersion of heat exchangers in coal
piles. This method can be used to control the temperature during both the
storage and transportation processes. The purpose of this study was to test
this method and, in particular, study the effect of changes in the
heat-exchange surface area on the effectiveness of temperature control. An
experiment was set up to control the temperature of a laboratory-scale coal
pile using a heat exchanger made from copper tubes. Coal samples were placed in
a cylindrical container with a spiral-shaped heat exchanger, placed in the
center of the cylindrical container, and cooled with ~27o seawater.
Tests were carried out using several configurations of heat exchanger
dimensions to determine the effect of changing the ratio of heat-exchange
surface area to volume of combustible material. The test results showed that
greater heat-exchange surface area produced a greater amount of cooling load
and temperature difference