Heat Loss

The purpose of this study was to optimise the combustion process of different residues in a mural boiler for domestic heating. The fuels used were pellets from three biomass residues (tomato, olive stone and cardoon (Cynara cardunculus L.)) and the forest pellet recommended by the boiler manufacturer. Previously, the fuels were characterised by means of the higher heating value, proximate and ultimate analyses. The influence of the residue type, fuel mass flow, draught and residue mixture on the combustion parameters was studied. A TESTO 300 M-I analyzer was used to determine the principal parameters of the combustion process (CO2, CO and O2 contents, fumes temperature, not-burnt gaseous and sensitive heat losses in the fumes, volumetric flow rate and velocity of the fumes, air excess coefficient, efficiency). The behaviour of the three residues is similar to that of the forest pellet. The boiler efficiencies obtained with the maximum fuel mass flow (100%) and minimum draught (0%) were 90%, 90.5%, 89.7% and 91.6% for tomato, forest, olive stone and cardoon pellets, respectively. The optimum residue mixture was tomato (75%) and forest (25%) with a boiler efficiency of 92.4% for a mass flow and draught of 75% and 0%, respectively.

The modeling, numerical simulation and control of a HVAC (heating, ventilating and air-conditioning) system having two different zones with variable flow-rate were performed by considering the ambient temperature in this study. The sub-models of the system were obtained by deriving to heat transfer equations of heat loss of two zones by conduction and convection, cooling unit and fan. All models

An understanding of the mechanisms of heat transfer is becoming increasingly important in today’s world. Conduction and convection heat transfer phenomena are found throughout virtually all of the physical world and the industrial domain. A thermal insulator is a poor conductor of heat and has a low thermal conductivity. In this paper we studied that Insulation is used in buildings and in manufacturing processes to prevent heat loss or heat gain. Although its primary purpose is an economic one, it also provides more accurate control of process temperatures and protection of personnel. It prevents condensation on cold surfaces and the resulting corrosion. We also studied that critical radius of insulation is a radius at which the heat loss is maximum and above this radius the heat loss reduces with increase in radius. We also gave the concept of selection of economical insulation material and optimum thickness of insulation that give minimum total cost.

Buildings with indoor swimming pools are recognised as very high-energy consumers and present a grate potential for saving energy. The management of indoor ambient conditions must act upon the most sensible parameters that affect the energy consumption; the energy is spending in several ways: Evaporation heat loss from the pool; ambient temperatures very high; and High rates of ventilation required. Control Strategies adapted to the reality of each building is an important way to reduce energy consumption. These paper presents control strategies that can implemented in the building automation system and the HVAC system of an existing indoor swimming pool complex, in order to minimise energy consumption. Taking into account the complexity of the parameters involved in a feasibility study of measures to reduce the energy consumption of the building, the choice of energy simulation programs is actually the better way, either from both economical and time perspectives, to quantify the b...

Energy benchmarking of processes is important for setting energy efficiency targets and planning energy management strategies. Most approaches used for energy benchmarking are based on statistical methods by comparing with a sample of existing plants. This paper presents a model based approach for benchmarking of energy intensive industrial processes and illustrates this approach for industrial glass furnaces.A simulation model for a glass furnace is developed using mass and energy balances, and heat loss equations for the different zones and empirical equations based on operating practices. The model is checked with field data from end fired industrial glass furnaces in India. The simulation model enables calculation of the energy performance of a given furnace design. The model results show the potential for improvement and the impact of different operating and design preferences on specific energy consumption. A case study for a 100 TPD end fired furnace is presented. An achievable minimum energy consumption of about 3830 kJ/kg is estimated for this furnace. The useful heat carried by glass is about 53% of the heat supplied by the fuel. Actual furnaces operating at these production scales have a potential for reduction in energy consumption of about 20–25%.

The process of heat transportation by means of heat distribution networks is accompanied by considerable heat losses, which has the impact on the overall operation of a heat distribution network as well as the efficiency of heat supply. Heat losses depend on several factors such as the temperature of transported working fluid, ambient temperature, design of the heat distribution system (channel, directly buried, underground, above-ground...), its length, the thickness and quality of the insulation material used.

Cement production has been one of the most energy intensive industries in the world. In order to produce clinker, rotary kilns are widely used in cement plants. This paper deals with the energy audit analysis of a dry type rotary kiln system working in a cement plant in Turkey. The kiln has a capacity of 600 ton-clinker per day. It was found that about 40% of the total input energy was being lost through hot flue gas (19.15%), cooler stack (5.61%) and kiln shell (15.11% convection plus radiation). Some possible ways to recover the heat losses are also introduced and discussed. Findings showed that approximately 15.6% of the total input energy (4 MW) could be recovered.