A microjet based recuperator for application in domestic micro chp

Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.In the paper the original design of a compact heat exchanger with microjets producing intensification effect is presented. Its primary application is for the domestic Organic Rankine Cycle (ORC), however, the design is universal and may have numerous other applications. The technology of microjets manufacturing is an “in-house” patented design. In the present paper the idea of such a heat exchanger is shown together with the flow and thermal characteristics of the prototype. The developed prototype of heat exchanger is capable of exchanging 5 kW of thermal energy at a logarithmic mean temperature difference (LMTD) of 60 K. The total heat transfer surface equal to 0.0072 m2 leads to very significant heat fluxes. Measured overall heat transfer coefficient reaches 12000 W/m2K, which was calculated using the Wilson method. The description of the Wilson technique used for the determination of the heat transfer coefficient is also presented in the body of the text. That method seems to be, in the authors’ opinion, the only one for finding the heat transfer coefficient for such a complex heat exchanger structure. In this case measurements of wall temperatures are not possible and hence the determination of heat transfer coefficient is difficult. The results of performed measurements are satisfactory and encourage for further research of the original design.pm201

Systems-wide analysis of manganese deficiency-induced changes in gene activity of Arabidopsis roots

Manganese (Mn) is pivotal for plant growth and development, but little information is available regarding the strategies that evolved to improve Mn acquisition and cellular homeostasis of Mn. Using an integrated RNA-based transcriptomic and high-throughput shotgun proteomics approach, we generated a comprehensive inventory of transcripts and proteins that showed altered abundance in response to Mn deficiency in roots of the model plant Arabidopsis. A suite of 22,385 transcripts was consistently detected in three RNA-seq runs; LC-MS/MS-based iTRAQ proteomics allowed the unambiguous determination of 11,606 proteins. While high concordance between mRNA and protein expression (R = 0.87) was observed for transcript/protein pairs in which both gene products accumulated differentially upon Mn deficiency, only approximately 10% of the total alterations in the abundance of proteins could be attributed to transcription, indicating a large impact of protein-level regulation. Differentially expressed genes spanned a wide range of biological functions, including the maturation, translation, and transport of mRNAs, as well as primary and secondary metabolic processes. Metabolic analysis by UPLC-qTOF-MS revealed that the steady-state levels of several major glucosinolates were significantly altered upon Mn deficiency in both roots and leaves, possibly as a compensation for increased pathogen susceptibility under conditions of Mn deficiency

Role of Plastid Protein Phosphatase TAP38 in LHCII Dephosphorylation and Thylakoid Electron Flow

Regulation of photosynthesis efficiency involves reversible phosphorylation of the light-harvesting complex through the activity of the newly identified phosphatase TAP38

Hard coal reserves of the Lower Silesian Coal Basin after the coal industry restructuring process and development prospects for the reserves

W artykule omówiono stan zasobów złóż węgla kamiennego pozostawionych po likwidacji kopalń w Dolnośląskim Zagłębiu Węglowym. W 1990 roku - rozpoczynającym restrukturyzację górnictwa - w 7 złożach zagłębia (w tym 5 eksploatowanych) było 457 min t zasobów bilansowych 1313 min t zasobów pozabilansowych, głównie węgla koksowego, specjalnego i antracytu. Obecnie, po zakończeniu eksploatacji i całkowitej likwidacji wszystkich kopalń, zasoby geologiczne całego zagłębia stanowią wyłącznie zasoby pozabilansowe w ilości 369 min t. Pojawiająca się w ostatnich latach koniunktura na światowych rynkach węgla (zwłaszcza na węgiel koksowy) spowodowała zainteresowanie niektórymi złożami węgla zlikwidowanych kopalń i możliwościami wznowienia eksploatacji. Wśród złóż kopalń wałbrzyskich na większą uwagę zasługuje złoże kopalni Victoria (pola Barbara i Witold). Występuje tu niemal wyłącznie węgiel koksowy, specjalny i antracytowy. Jego zasoby w pokładach o grubości przynajmniej 1,20 m (kryterium stosowane obecnie do obliczenia zasobów przemysłowych węgla koksowego i specjalnego) wynoszą ok. 58,5 min t. Ujemną cechą tego złoża są niekorzystne warunki geologiczno-górnicze, w tym zwłaszcza zagrożenia gazowe i wyrzutowe. Interesujące mogłyby być również zasoby antracytu w złożu Wałbrzych-Gaj (jedyne tego typu złoże w Polsce), jednak wobec całkowitej likwidacji infrastruktury kopalni, w tym szybów, zasoby te wydają się być stracone (ok. 20 min t zasobów przemysłowych przed zakończeniem eksploatacji). W podobnej sytuacji są pozostałe złoża w rejonach Wałbrzycha i Nowej Rudy; niewielkie ilości zasobów o znaczeniu przemysłowym, trudne warunki geologiczno-górnicze i brak dostępu do ztóż ze względu na całkowitą likwidację szybów wydają się wykluczać możliwości ich udostępnienia metodami górniczymi, czyli poprzez budowę nowych kopalń. Można jednak założyć ponowne zagospodarowanie tych złóż w przyszłości metodami niekonwencjonalnymi poprzez zgazowanie pokładów węgla.The paper presents the study results concerning the hard coal reserves still existing after closure of coal mines in the Lower Silesian Coal Basin (SW Poland). In 1990, when the coal industry restructuring process started, there were seven coal deposits (of which five still under exploitation). They consisted of 457 million tons of economic and potentially economic reserves and 313 million tons of potentially economic reserves represented mainly by coking coal, anthracite coal and anthracite. Nowadays, after the end of coal mining, the geological reserves of the Lower Silesian Coal Basin are 369 million tons of potentially economic reserves. The boom that occurred over the last years in the world coal market (especially demand for coking coal) has caused an increased interest in the abandoned coal deposits and possibilities of exploitation reopening. In the Wałbrzych area, the most interesting among the existing coal deposits is that of the former Victoria mine (Barbara and Witold coalfields). It predominantly contains coking coal, anthracite coal and anthracite. Its reserves amount to 58.5 million tons (calculated for at least 1.20 m thick seams). Disadvantage of the deposit is unfavourable geological and mining conditions, especially danger of coal and gas outburst. The anthracite reserves of the Wałbrzych-Gaj deposit (the only Poland's deposit of this type) are interesting, but as the entire mine's processing buildings, shafts etc. have been pulled down, the reserves seem to be lost (approx. 20 million tons just before the end of mining). The remaining deposits in the Wałbrzych and Nowa Ruda regions are in a similar situation. Insignificant amounts of economic reserves, difficult mining conditions, total demolishment of mineshafts and processing plant buildings etc. give no chance for exploitation by deep mining methods through establishing of new mines. It can be assumed that the potential future development of coal deposits in the Lower Silesian Coal Basin is possible by unconventional methods, like the underground gasification of coal seams

Teoretyczny model ciągły dla obiegu kogeneracyjnego ORC

W pracy przedstawiono wyniki obliczeń obiegu ORC w warunkach eksploatacyjnych. Przeprowadzone obliczenia umożliwiają określenie bezwładności układu podczas zmiany obciążeń cieplnych parownika i skraplacza. Z obliczeń uzyskano czasy bezwładności oraz parametry temperatury na dolocie do turbiny i skraplacza dla czynnika R123. Bardzo zbliżone wyniki obliczeń parametrów uzyskanych z własnego modelu obiegu ORC do przeprowadzonego niezależnie eksperymentu dają podstawy do stwierdzenia, że model dobrze odzwierciedla układy rzeczywiste. Podkreślić należy fakt, że obliczenia dynamiki obiegu za pomocą tego modelu przeprowadzono dla różnych czynników roboczych (R123, HFE7100, propan) uzyskując dobre jakościowo wyniki, co pozwala poszerzyć zakres jego stosowalności również na inne czynniki robocze. Wyniki własnych obliczeń porównano z badaniami eksperymentalnymi obiegu ORC innych autorów uzyskując dobrą zgodność.This article presents results of calculations of the organic Rankine cycle (ORC) in working conditions. The calculations make it possible to define the inertia of the evaporator and condenser while the heat loads change occurs. Calculations allow to get the inertia of the system, and the parameters of temperature at the inlet to the turbine and condenser for the R123 refrigerant. Very similar calculations results of the parameters were obtained from own model for ORC cycle, and experiment results performed independently gave basis to conclude that the model well reflects the real systems. It should be emphasized that the dynamics calculations for the cycle prepared by this model was conducted for different working fluids (R123, HFE7100, propane). Good quality of the results from these calculations, allows to expand the scope of the model applicability to other working fluids. Our own results of calculations were compared with other authors experimental studies of the ORC cycle obtaining a good compliance

Wałbrzych Geoturist Area - inventory of geotopes for promotion of geoturism

The paper presents inventory and results of valorization of geotopes located in the Walbrzych region. This region is situated in south-western Poland, in proximity of the Wałbrzych Foothills (Bolków-Wałbrzych Foothills), Wałbrzych Mts., Kamienne Mts. and Sowie Mts. and Kamienna Góra Basin. The 149 geotopes which represents 6 geological themes - sedimentology, volcanism, metamorphism, geomorphology, hydrogeology, geology of Quaternary - have been selected and evaluated. All the data collected for these sites are stored in the database and may be displayed on several thematic maps. Based on results of valorization of geotopes, analyses of geology and geomorphology of the area as well as evaluation of land development, the seven geotourist sub-areas (so-called domains) have been differentiated. The results of the geotopes inventory and valorization indicate a possibility to propose a new geotourist area in the studied region and name it "Wałbrzych Geotourist Area"

Changes of the thermodynamic parameters in failure conditions of the micro-CHP cycle

The paper presents the calculations for the failure conditions of the ORC (organic Rankine cycle) cycle in the electrical power system. It analyses the possible reasons of breakdown, such as the electrical power loss or the automatic safety valve failure. The micro-CHP (combined heat and power) system should have maintenance-free configuration, which means that the user does not have to be acquainted with all the details of the ORC system operation. However, the system should always be equipped with the safety control systems allowing for the immediate turn off of the ORC cycle in case of any failure. In case of emergency, the control system should take over the safety tasks and protect the micro-CHP system from damaging. Although, the control systems are able to respond quickly to the CHP system equipped with the inertial systems, the negative effects of failure are unavoidable and always remain for some time. Moreover, the paper presents the results of calculations determining the inertia for the micro-CHP system of the circulating ORC pump, heat removal pump (cooling condenser) and the heat supply pump in failure conditions