Surface temperature of the exposed silo face as quick indicator of the decomposition process of maize silage

Silage temperature and oxygen concentration are critical parameters for controlling the silage process. Anaerobic condition with lower and stable temperature is necessary for quality silage making. However, when the silo is opened or if there are any failures (e.g. at the cover or at the walls) the anaerobic environment is changed to an aerobic state. That caused intensive decomposition process allied to increase of the temperature in the problematic silage layers. The objective of the current study is to evaluation of infrared thermography technique possibilities for measurement of surface temperature of the maize silage under conditions representative of an exposed face silo, interpretation of measured values and detection of layers and areas with intensive decomposition process

Quantitative Risk Assessment of Biogas Plant – Determination of Assumptions and Estimation of Selected Top Event

Biogas plants are a specific facility from the QRA (Quantitative Risk Assessment) methodologies' point of view, especially in the case of the determination of the event frequency of accident scenarios for biogas leakage from a gas holder and subsequent initiation. QRA methodologies determine event frequencies for different types of accident events related to vessels made of steel. Gas holders installed at biogas plants are predominantly made of other materials and are often integrated with the fermenter. It is therefore a specific type of gas holder, differing from that which is commonly used in the chemical industry. In addition, long-term experience is not available for the operation of biogas plants, unlike in the chemical industry. The event frequencies listed in the QRA methodologies are not relevant for the risk assessment of biogas plants. This work is focused on setting the prerequisites for QRA of biogas storage, including for example: information on hazardous chemical substances occurring at biogas plants, their classification, and information on the construction of integrated gas holders. For the purpose of the work, a scenario was applied where the greatest damage (to life or property) is expected. This scenario is the leakage of the total volume of hazardous gas substance from the gas holder and subsequent initiation. Based on this information, a "tree" was processed for "Fault Tree Analysis" (FTA), and frequencies were estimated for each event. Thereafter, an "Event Tree Analysis" was carried out. This work follows up on a discussion by experts on the determination of scenario frequencies for biogas plants that was conducted in the past

Modelování následků úniku bioplynu z plynojemu

This paper describes modelling of consequences of biogas leakage from a gasholder on agricultural biogas station. Four scenarios were selected for the purpose of this work. A rupture of gasholders membrane and instantaneous explosion of gas cloud, blast of gas with delay, emptying of whole volume of gas (without initiation) and initiation of gas with Jet-Fire. Leakage of gas is modelled by special software and consequences are determined on the basis of results. The first scenario was modelled with help of equations because used software does not include an appropriate model. A farm with high building density was chosen as a model case. Biogas is replaced by methane because used software does not support modelling of dispersion of mixtures. From this viewpoint, a conservative approach is applied because biogas contains “only” approximately 60% of methane (in dependence on technology and processed material).Tento příspěvek popisuje modelování následků úniku bioplynu ze zásobníku na zemědělské bioplynové stanici. Pro účely této práce byly vybrány čtyři scénáře. Porušení membrány plynojemu a okamžitý výbuch plynového mraku, výbuch plynu se zpožděním, vyprázdnění celého objemu plynu (bez iniciace) a únik plynu s iniciací Jet-Fire. Únik plynu je modelován softwarem a důsledky jsou stanoveny na základě výsledků. První scénář byl modelován pomocí rovnic, protože použitý software neobsahuje vhodný model

The Safety of Biogas Gasholders

Příspěvek se zaměřuje na bezpečnost zásobníků bioplynu. V první části jsou vymezeny konstrukční typy zásobníků, které se využívají na bioplynových stanicích. Další část shrnuje nejčastější příčiny havárií na zásobnících plynných a kapalných uhlovodíků a uvádí je do souvislosti s havarijními situacemi na bioplynových stanicích. Poslední část upozorňuje na základní bezpečnostní zařízení, jimiž musí být tyto zásobníky vybaveny.The work is focused on safety of biogas gasholder. In the fi rst part design types of gasholder utilizing on biogas stations are defi ned. The next part of work summarizes the most common causes of accidents on gasholders of gaseous and liquid hydrocarbons. These causes are given to relationship with emergency situations on biogas plants. The last part warns on elementary safety barriers, which must be included in gear of a gasholder

FRAM telescopes and their measurements of aerosol content at the Pierre Auger Observatory and at future sites of the Cherenkov Telescope Array

A FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a system of a robotic mount, a large-format CCD camera and a fast telephoto lens that can be used for atmospheric monitoring at any site when information about the atmospheric transparency is required with high spatial or temporal resolution and where continuous use of laser-based methods for this purpose would interfere with other observations. The original FRAM has been operated at the Pierre Auger Observatory in Argentina for more than a decade, while three more FRAMs are foreseen to be used by the Cherenkov Telescope Array (CTA). The CTA FRAMs are being deployed ahead of time to characterize the properties of the sites prior to the operation of the CTA telescopes; one FRAM has been running on the planned future CTA site in Chile for a year while two others are expected to become operational before the end of 2018. We report on the hardware and current status of operation and/or deployment of all the FRAM instruments in question as well as on some of the preliminary results of integral aerosol measurements by the FRAMs in Argentina and ChileComment: Proceedings of AtmoHEAD 201