Quantitative and qualitative analysis of contaminating hydrocarbons in the Gulf of Santiago de Cuba by gas chromatography

The coasts of Cuba are exposed to damage caused by the contamination by petroleum hydrocarbons. The coastal strip of the Gulf of Santiago de Cuba is an example of natural resources deterioration due to this contamination, which appears as one of its main environmental problems. In the present work, using gas chromatography, quantitative and qualitative analysis were performed based on the retention time values and the area under the chromatogram curve, which allowed characterizing the degree of contamination at four points of the bay of Santiago de Cuba: playa La Estrella (P1), “Guillermón Moncada” Port (P2) “Hermanos Díaz” Oil Refinery (P3), “Antonio Maceo” Thermoelectric Power Plant RENTE (P4). Retention times of individual peaks in chromatograms of individual samples with several standards, thus obtaining the types of hydrocarbons present at each point, with points P2 and P3 being the ones with the highest pollutant and the highest concentration by peak height. Fuel oil turned out to be the most polluting agent present in the bay.

Numerical and experimental investigation of alumina-based nanofluid effects on double-pipe heat exchanger thermal performances

In this study, we investigate the thermal behaviour of nanofluids in a double-pipe heat exchanger. It is about a counterflow configuration, designed to cool a lubrication unit of a thermoelectric power plant. The subject of this work is to evaluate the thermal performances of the exchanger by using a nanofluid based on alumina suspension comparing with deionized water. In order to evaluate the thermal performance of the studied configuration, we carried out numerical experiments in an application developed on COMSOL Multiphysics environment, these experiments are utilized to show the feasibility of this application. As result, we found that the nanofluid with an increase in its volume fraction leads to an increase in the overall exchange coefficient, the convective heat transfer coefficient, as well as the efficiency and the power of the exchanger. It is noted that an increase of 1% in volume fraction, can enhance the overall exchange coefficient, the power and the effectiveness of the exchanger by 17.62%, 1.473% and 10.80% respectively. Besides, it is noted that the increase in the concentration of nanofluids leads to a narrowing of the pinch points of the inlet and outlet temperatures, which means that nanofluids are more efficient in cooling temperatures than conventional fluids.

Experimental study on the determination of average concentrations of polluting emissions for a thermoelectric power plant

There is the problem of determining the polluted emissions in the case of a thermal power plant that uses coal as the main fuel in the Jiu Valley Mining Basin. The experimental determinations were performed at the points located behind the electrostatic precipitators and at the accessible points located behind the flue gas fans. These targeted mass flows and concentrations for indicators: O2, CO, CO2, NOx, SO2, dust: PM 10, PM 2.5, and total. The paper presents the values of average concentrations, determined experimentally, regarding pollutant emissions, including dust. The emissions for the analyzed energy groups were determined, for each category of polluting emissions comparative histograms were made.

Use of portable environmental sensors in the monitoring of the thermoelectric power plants operation

Thermoelectric power plants can directly cause environmental impacts with respect to emissions of atmospheric gases caused by combustion for operation, being the main agents: unburned hydrocarbons, carbon oxides, sulfur oxides, nitrogen oxides, volatile organic compounds and material particulate. Thus, this research aimed to measure and compare the instantaneous levels of the chemical compounds CO2, CO, SO2, noise, air temperature, relative humidity, dew point temperature, wind speed and luminescence in two peri-urban areas of the surrounding a thermoelectric power plant in the interior of Paraíba, Brazil. To this end, data were collected using environmental sensors (a Garmin Gpsmap 62sc GPS camera 5mp; a Canon powershot SX60HS 16.1MP LCD 3.0 semi-professional digital camera, 65x optical zoom; an ITMCO2-600 meter for measuring CO2 and CO; one ITMP-600 multifunctional meter for AVG/MAX/MIN/DIF measurement, temperature measurement, humidity measurement, sound level measurement, luminescence measurement and wind speed measurement; and a GasAlert Extreme SO2 Gas detector to measure concentrations of sulfur in the environment), from October 2015 to March 2017, during daytime, between 7:00am to 9:00am, with weekly frequency, with instantaneous sampling measurements being collected at the collection points, near the thermoelectric power plant (Area 1) and close to the BR/104 highway (Area 2). The results showed that the records through the environmental sensors were not significant among the areas surveyed regarding the values of CO, CO2, SO2, air temperature, relative humidity, dew point temperature and luminescence. Regarding the wind speed, the two areas showed little variation. The noise levels in Area 1, on the other hand, during the operation of the thermoelectric power plant in its fullness, there was an increase above the permitted level, according to current Brazilian regulations, causing damage to the health of the inhabitants of its surroundings, in addition to harming the fauna of the surrounding area. around, mainly, the birds that are driven away by the noise, and, consequently, reducing the diversity of the avifauna surrounding the Thermoelectric. Thus, the use of environmental sensors to monitor the air quality of this area is very important, thus serving as a comparative support for future studies, as well as establishing the genesis for an environmental database in this metropolitan region of Campina Grande/PB, Brazil.

Aspects of the study of the increase of the energy efficiency in the operation of the induction motors within the ancillary services of a thermoelectric power plant

In this paper, the authors systematized and interpreted the results obtained by running their own design computing programs, developed using the facilities offered by the Mathcad mathematical software package combined with facilities offered by appropriate custom chart wizard, provided by Excel. These programs were developed based on the algorithms for calculating the parameters of the equivalent scheme, the electrical balance components and the energy efficiency indicators (efficiency, power factor) for a three-phase induction motor with squirrel cage rotor with deep rectangular bars within the ancillary services of a thermoelectric power plant, using a complete mathematical model for different degrees of loading.