Aivars Žandeckis

Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building

Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building The paper focuses on the application of wood pellet and solar combisystem for space heating and hot water preparation at apartment buildings under the climate of Northern Europe. A pilot project has been implemented in the city of Sigulda (N 57° 09.410 E 024° 52.194), Latvia. The system was designed and optimised using TRNSYS - a dynamic simulation tool. The pilot project was continuously monitored. To the analysis the heat transfer fluid flow rate and the influence of the inlet temperature on the performance of solar collectors were subjected. The thermal performance of a solar collector loop was studied using a direct method. A multiple regression analysis was carried out using STATGRAPHICS Centurion 16.1.15 with the aim to identify the operational and weather parameters of the system which cause the strongest influence on the collectors performance. The parameters to be used for the systems optimisation have been evaluated. Daudzdzīvokļu Ēkai Uzstādītās Kombinētas Sistēmas Saules Kolektoru Veiktspējas Analīze Rakstā aplūkota saules un granulu kombinētā sistēma, kas Ziemeļeiropas klimatiskajos apstākļos nosedz daudzdzīvokļu ēkas apkures un karstā ūdens slodzes. Pilotprojekts tika īstenots Siguldā (N 57° 09.410 E 024° 52.194), Latvijā. Sistēma izveidota un optimizēta, izmantojot datorsimulācijas programmu TRNSYS. Rakstā īstenota sistēmas darbības analīze pēc iekārtu uzstādīšanas, organizējot nepārtrauktu monitoringu. Analizēta siltumnesēja plūsmas un temperatūras līmeņu ietekme uz saules kolektoru veiktspējas rādītājiem. Regresijas analīze veikta STATGRAPHICS Centurion 16.1.15 vidē, lai noteiktu, kuri no darbības un klimatiskajiem apstākļiem visvairāk ietekmē saules kolektoru efektivitāti. Izvērtēti nepieciešamie sistēmas optimizācijas parametri. Iegūts empīriskais modelis saules kolektoru efektivitātes noteikšanai.

Determination of Solid Particle Concentration at Coal Transshipment Site

Determination of Solid Particle Concentration at coal Transshipment site Coal handling and grinding processes are associated with significant particulate matter emissions into the atmosphere. This problem is particularly urgent when a coal-processing company is located in or nearby a densely populated city. To quantitatively evaluate concentrations generated into the atmosphere according to the standardized methodology, it is necessary to make extensive measurements using an automatic real-time, infrared dust and aerosol monitor. Before the experiments, the impact of particulate matter on human health and the environment was explored, six solid particle concentration detection methods and best available techniques for particulate matter emission prevention was described. During this study field measurements were carried out at on the territory of a coal transshipment company. Using the solid particle concentration detection system Dust Detective kit, concentration monitoring of total particulate matter (TSP), PM10 and PM2.5 was carried out. The equipment was located 6 m above ground and 120 m away from the emission source - coal crushing and handling site. TSP monitoring was carried out during four diurnal, PM10 - during 17 diunral and PM2.5 - during 12 days. After comparison of results with concentration values set in normative documents of Latvia and EU, it was found out that average 17 diurnal day concentration values of PM10 exceeded normative values for nine times. PM2.5 daily average concentrations of 12 days exceeded for four times exceeded the value of 25 μg/m3, which is mentioned in Directive 2008/50/EC of EU. After analysis of wind behaviour impact on the concentration values it is now understood that if wind comes from the dust emission source to the measurement system, the increase in wind speed increases particle concentration as all particles in the air and those raised from coal piles are driven towards the equipment. If wind comes from the opposite direction, the decrease of wind velocity results in an increase of concentration values as emitted dust cloud stays within the territory of the measurement. It was observed that wind speed causes the concentrations to change gradually, but wind direction is responsible for rapid concentration changes. The obtained results prove that there is an urgent problem with significant particulate matter emissions into the air at the coal transshipment site. It is necessary to take preventive measures to reduce dust emissions from the coal handling and grinding processes in this company. Overall after this study the situation of coal transshipment site impact level on air quality has become more clear and it is apparent that much stricter regulations must be introduced for coal processing sites.