WASTE HEAT GENERATION AND POTENTIAL RECOVERY SYSTEMS USED IN SRI LANKAN HOTELS

The waste heat recovery concept can be used as a solution to optimise energy consumption while reducing the waste heat in energy generation systems. However, its application in Sri Lankan hotels is still in the infancy stage even though the hotel sector accounts for high energy consumption. Therefore, this research aimed to assess the amount of waste heat generated from the different sources in hotel buildings and thereby identify the most appropriate waste heat recovery systems to the hotel buildings in Sri Lanka through a comparative case study analysis of three similar natured hotel buildings. The required data to perform waste heat calculation were extracted through document reviews and site visits. This study identified the three main waste heat generating sources in hotel buildings: HVAC condenser out, boiler exhaust, and kitchen exhaust. The analysis shows that the condenser out of the HVAC system is the highest waste heat generating source which accounts for an average of 41,823GJ per year while boiler exhaust and kitchen exhaust generate the waste heat of an average of 11,000GJ and 8GJ per year. It is further found that the quality of waste heat generated from the boiler exhaust is higher than the condenser out of the HVAC system and kitchen exhaust. Hence, this study concludes that the boiler has the highest potential of using the waste heat recovery system than the condenser out of the HVAC.

Methodologies of heat calculation and selection of rational parameters of regenerative burners operation

Decrease of energy intensity of products is an actual task for all the industries, including steel industry. One of the best solutions to increase energy efficiency of heating facilities is application of recuperative and regenerative burners, which ensure high temperature of air heating. Such high temperatures cannot be achieved at application of heating systems based on central recuperator. It was shown that many countries accomplish studies to perfect recuperative burners and simulation of their thermal operation. However at present there are no universally recognized methodologies of calculation and designing of such equipment. Results of studies presented, which were implemented in three methodologies intended for heat calculation and selection of rational parameters of regenerative burners operation. The methodologies enable also to determine a fuel utilization coefficient for a furnace system based on regenerative burners, to estimate competitiveness of solutions at creation new and modernization existing furnaces comparing with utilization of modern central recuperators. Comparative simplicity of the mathematical apparatus used in the methodologies highlighted, as well as correspondence of the used calculated expressions to the physical nature of the processes taking place. Besides, the methodologies enable during calculation to set the values of important characteristics, which can be reached based on determination of values of basic structure parameters of lining. A scheme of joint application of the elaborated methodologies proposed.

Geothermal Resources Recognition and Characterization on the Basis of Well Logging and Petrophysical Laboratory Data, Polish Case Studies

Examples from the Polish clastic and carbonate reservoirs from the Central Polish Anticlinorium, Carpathians and Carpathian Foredeep are presented to illustrate possibilities of using well logging to geothermal resources recognition and characterization. Firstly, there was presented a short description of selected well logs and methodology of determination of petrophysical parameters useful in geothermal investigations: porosity, permeability, fracturing, mineral composition, elasticity of orogeny and mineralization of formation water from well logs. Special attention was allotted to spectral gamma-ray and temperature logs to show their usefulness to radiogenic heat calculation and heat flux modelling. Electric imaging and advanced acoustic logs provided with continuous information on natural and induced fracturing of formation and improved lithology recognition. Wireline and production logging were discussed to present the wealth of methods that could be used. A separate matter was thermal conductivity provided from the laboratory experiments or calculated from the results of the comprehensive interpretation of well logs, i.e., volume or mass of minerals composing the rocks. It was proven that, in geothermal investigations and hydrocarbon prospection, the same petrophysical parameters are considered, and well-logging acquisition equipment and advanced methods of processing and interpretation, developed and improved for almost one hundred years, can be successfully used in the detection and characterization of the potential geothermal reservoirs. It was shown that the newest (current investment)—as well as the old type (archive)—logs provide useful information.

FEATURES OF THE SOURCE TERM CALCULATION CAPABILITY OF THE NECP-X CODE

The source term calculation capability is developed for the high-fidelity neutronics code NECP-X. Generally, a full activation library is used, but the memory requirement is unacceptable for the high-fidelity calculation. In order to minimize the memory requirement during the calculation with very strict conditions, a new generalized activation chain compressed method is proposed based on the influence qualification. One basic compression element is a reaction channel or an isotope, and the influence of every compression element to the final results are qualified. To enlarge the range of application of the new compressed library, an effective method to determine representative problems, which utilizes the neutron spectra and neutron flux, is developed and analyzed. Based on the ENDF-VII.0, EAF-2010 evaluated nuclear library and the influence qualification-based activation library compression method, a new compressed activation library is generated. The VERA-3A problem and the KAIST problem are used to assess the accuracy and the efficiency of the new activation library. 85 measurements of decay heat from decay heat measurement facilities GE-Morris and CLAB are used to validate the decay heat calculation in NECP-X. The results show good accuracy of NECP-X in predicting radiation source term of the spent nuclear fuel and significant memory saving when using new compressed activation library.

Methodology Applied for Thickness Selection and Stored Heat Evaluation in Non-producer Geothermal Wells in Order to Its Investment Rescue

An assessment methodology of stored heat in rock formation surrounding to wellbore in geothermal systems is shown. Due to geothermal systems generally are nested in volcanic rock, it is characteristic its heterogeneous behavior. Proposed methodology starts since zone selection with possibilities of heat store. This methodology is focused to be applied in geothermal reservoirs with tendency to production decline, due to low permeability and unbalance between exploitation and water recharge. Because the high costs of drilling geothermal wells, methodology shown in this work is proposed to be applied in those with production decline or non-producers, in order to rescue its investment. The objective is to select the thickness with heat, evaluate its storage, design the appropriate instrumentation for its recovery, its energy conversion and rescue its investment done. The different designs for energy recovery using non-conventional methods to those, used habitually are reviewed. Each one of the variables for stored heat calculation was determined using technical tools of reservoir engineering. A parametric analysis about variables sensitivity (porosity and drainage radius) for determining thermal energy and corresponding electric energy of analyzed rock volume is done. Practical application of this methodology was carried out using data of one of wells of Los Humeros Mexican geothermal field.

Single-plate Swipe Couplings On Four-wheeled Vehicles

The clutch is an absolutely necessary part of the gasoline cars and the other types where the main drive is obtained from the fuel in the cylinder. The author starts planning this friction coupling with the theory and shifting system of style, then determines the type of clutch plate to be worn, determining the large diameter of the clutch shaft, specifies the thick of the friction plate, the spring reducer, the flywheel connecting Bolt with the flux, the flywheel connecting bolt with the engine shaft, the rivet connector of the friction plate with the spring disc, the rivet of the disc-connector with the sub plate, the rivet of the sub-plate and the spline hub, the rivet of the Cover flux, clutch shaft bearings, bearing holders, as well as heat calculations and age of friction plates. Specifies the type of clutch plate to be worn, determining the large diameter of the clutch shaft, determining the thick of the friction plate, the damper spring, the flywheel connecting Bolt with the flux, flywheel connecting bolt with engine shaft, rivet swipes with friction plate with disc spring, Rivet Connector Spring with sub plate, rivet sub plate rivets with spline hub, rivet fastening rivets with flux cover, clutch shaft bearings, bearing holders, as well as heat calculation and age of friction plates. Single-plate swipes are designed so that they can transmit power/rotation in a rotating or unrotating state. The type of coupling discussed here is the fixed clutch that uses a plate that serves as a medium of friction between the flywheel and the pressing plate. The purpose of writing these planning tasks to meet and complement the course of the machine element, the authors try to plan and discuss the clutch system

The analytical assessment of heat calculation methods of DKVr-10-13 liquid fueled steam boilers

The article presents an analytical assessment of the methodology of the last two editions for boiler units` heat calculation developed by two Russian scientific research institutes - All-Russia Thermal Engineering Institute (VTI) and I. I. Polzunov Scientific and Development Association on Research and Design of Power Equipment (TsKTI). The methods` comparison analysis was carried out using the author’s calculation programs, compiled according to the last two editions, and the results collating was carried out based on the maps of operational tests of the DKVr-10-13 steam boiler installed in the heating and industrial boiler house in St. Petersburg. The main balance values and specific performance indicators of the DKVr-10-13 boiler unit were subjected to comparative analysis, the dependencies of which are presented and analyzed in the article.