Co-digestion of algae biomass for production of biogas and fertilizer: Life Cycle Cost Analysis

The purpose of this article is to determine and assess Life Cycle Costs of biogas and fertilizer produced in anaerobic digestion of biomass. General Cost Breakdown Structure for anaerobic digestion plant is described for better understanding of the system. Main cost categories discussed in this study are: Investments; Design, construction and dismantling costs; Maintenance, Operation and Transportation costs. Results showed that Design, construction and dismantling costs have the biggest share in Total Life Cycle Cost (TLCC) per cubic meter of biogas. This category also has the biggest influence on TLCC of fertilizer. Investment costs are the second most significant cost category

VĒSTURISKO ĒKU ENERGOEFEKTIVITĀTES PAAUGSTINĀŠANA AUKSTAJĀ KLIMATISKAJĀ ZONĀ

Latvija un tajā skaitā Latgale ir bagāta ar ēkām, kuras celtas pirms Otrā pasaules kara un ir būtiska pilsētu un lauku teritoriju ainavas sastāvdaļa. Taču, salīdzinot ar mūsdienu energoefektivitātes prasībām, to enerģijas patēriņš un ietekme uz klimata pārmaiņām ir liela. Viens no tehniskajiem risinājumiem, kuru var izmantot ēkās, kuru siltināšana no ārpuses nav pieļaujama, ir ēku siltināšana no iekšpuses. Lai gan ir pieejami dažādi materiāli un tehnoloģiskie risinājumi, ēku siltināšana no iekšpuses prasa daudz lielāku uzmanību veltīt higrotermālajiem procesiem sienas iekšienē, detalizēti analizējot siltuma un mitruma pārvietošanos un uzkrāšanos materiālos. Kļūdaini risinājumi var radīt būtiskus bojājumus ārsienās, t. sk. materiālu degradāciju sasalšanas-atkušanas ciklu ietekmē un pelējuma sēnes veidošanos konstrukcijā. Pētījuma galvenais mērķis ir noteikt, kādi higrotermālie procesi notiek vēsturisko ēku ārsienās kritiskajās vietās aukstajā klimatiskajā zonā, izmantojot ūdens tvaiku necaurlaidīgu siltumizolāciju, ūdens tvaiku daļēji caurlaidīgu siltumizolāciju un kapilāri aktīvu siltumizolācijas materiālu. Pētījumā veikta higrotermālo procesu modelēšana ar dinamisko modelēšanas rīku Delphin. Pētījums tapis Valsts pētījumu programmā „LATENERGI“ un projektā „RiBuild“

Construction Sector Needs to Achieve the Climate and Energy Targets 2020

The aim of the analysis hereby was to determine the demand for employees in the construction sector and to forecast it for year 2020 in order to achieve the climate and energy targets the country has undertaken

Laboratory Works in Industry. Possibilities

Izbraukuma laboratorijas darbi rūpnieciskos apstākļos. Iespējas. Rakstā apskatīti un analizēti RTU, Vides aizsardzības un siltuma sistēmu institūtā realizētie izbraukuma laboratorijas darbi rūpniecības apstākļos – siltuma zudumu no katla virsmām un katla energoefektivitātes noteikšana.Tiek apskatītas pozitīvās un negatīvās iezīmes realizējot šāda veida laboratorijas darbus. Rakstā izklāstītas galvenās atšķirības laboratorijas darba sagatavošanas un izpildes posmā, kā arī aplūkotas rezultātu analīzes iespējas sistēmas ietekmes izvērtējumam. Atzīmēti arī minēto laboratorijas darbu trūkumi – piesaiste iekārtas darbināšanas režīmiem un ierobežotas to izmaiņu iespējas .Rakstā iztirzātas iespējas attīstīt šāda veida laboratorijas darbus arī citos VASSI piedāvātajos priekšmeto

Green Roof Water Retention Modeling by SWMM

Green roof capability of rainwater runoff retention by accumulating it in storage layers and conduction back in atmosphere by evapotranspiration is studied and modeled in this paper. Modeling is done in Stormwater Management Model 5.0 (SWMM) software. Model is based on existing warehouse type building located in Riga and hourly Riga climatic data of 2012. Evaluation of model is carried and future study fields of green roof ecological benefits are discussed

Multi-Objective Optimization Approach for Improving Performance of Building

Energy efficiency measures are different from energy efficiency and cost effectiveness perspective. For decision maker it is hard to make right decision about different energy efficiency measure combinations in building. It is a complex problem to choose the best energy efficiency measure combination as decision involves many different factors that should be taken in account. Decision on implementation of energy efficiency measure implementation usually depends on investment costs and pay back time. Standards like Latvian Building Code LBN 002-01 can’t be used to achieve reasonable expenses in renovation of buildings. Therefore, in order to find the optimal energy-efficiency measures, it is necessary to carry out optimization taking all the variable parameters into account. In the paper target function was presented that gives ability of the multi-objective optimization approach to handle the problem of improving energy efficiency in buildings. Case study is used to demonstrate the feasibility of the approach. 104. series soviet type dwellings was analysed to optimized insulation thickness for external walls. Even if accord with the LBN 002-01 it is enough to use 7 cm thick isolation (λ-0,039 W/(m2K)) layers optimal insulation layer is 12 cm (λ-0,039 W/(m2K))

Passive house in Latvia

The paper considers the scope for building the so-called passive houses in Latvia. For modeling a passive house that could be adapted to the Latvian climate, the computer program TRNSYS has been created, which made it possible to obtain the thermally-technical parameters that are needed for designing private houses in Latvia and meet the passive building criteria

Passive House in Latvia

The paper considers the scope for building the so-called passive houses in Latvia. For modeling a passive house that could be adapted to the Latvian climate, the computer program TRNSYS has been created, which made it possible to obtain the thermally-technical parameters that are needed for designing private houses in Latvia and meet the passive building criteria