Ivars Veidenbergs

District Heating Systems Performance Analyses. Heat Energy Tariff

Abstract The paper addresses an important element of the European energy sector: the evaluation of district heating (DH) system operations from the standpoint of increasing energy efficiency and increasing the use of renewable energy resources. This has been done by developing a new methodology for the evaluation of the heat tariff. The paper presents an algorithm of this methodology, which includes not only a data base and calculation equation systems, but also an integrated multi-criteria analysis module using MADM/MCDM (Multi-Attribute Decision Making / Multi-Criteria Decision Making) based on TOPSIS (Technique for Order Performance by Similarity to Ideal Solution). The results of the multi-criteria analysis are used to set the tariff benchmarks. The evaluation methodology has been tested for Latvian heat tariffs, and the obtained results show that only half of heating companies reach a benchmark value equal to 0.5 for the efficiency closeness to the ideal solution indicator. This means that the proposed evaluation methodology would not only allow companies to determine how they perform with regard to the proposed benchmark, but also to identify their need to restructure so that they may reach the level of a low-carbon business.

Methodologies Used for Scaling-up from a Single Energy Production Unit to State Energy Sector

Abstract In a well-functioning and sustainable national energy sector, each of its elements should function with maximum efficiency. To ensure maximum efficiency and study possible improvement of the sector, a scaling-up framework is presented in this work. The scaling-up framework means that the starting point is a CHP unit and its operation, the next step of aggregation is in a district heating network, followed by a municipal energy plan and finally leading to a low carbon strategy. In this framework the authors argue, that the successful, innovative practices developed and tested at the lower level of aggregation can be then transferred to the upper levels of aggregation, thus leading to a scaling-up effect of innovative practices. The work summarizes 12 methodologies used in the energy sector, by dividing these methodologies among the levels of aggregation in a scaling-up framework.

Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects

Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects The paper contributes to the analyses from the environmental and economical point of view of small scale solar cooling system in climate conditions of Latvia. Cost analyses show that buildings with a higher cooling load and full load hours have lower costs. For high internal gains, cooling costs are around 1,7 €/kWh and 2,5 €/kWh for buildings with lower internal gains. Despite the fact that solar cooling systems have significant potential to reduce CO2 emissions due to a reduction of electricity consumption, the economic feasibility and attractiveness of solar cooling system is still low.

Non-thermal Plasma for VOC Treatment in Flue Gases

Non-thermal Plasma for VOC Treatment in Flue Gases The paper discusses non-thermal plasmas, their generation and characteristics, formation mechanisms of ozone and the treatment of volatile organic compounds (VOCs). In the experimental part, undecane (C11H24 as model VOCs) was treated with assistance of low temperature plasma at an atmospheric pressure which was generated in the so-called stack reactor. The gas composition was 13% of oxygen in nitrogen with impurities of carbon dioxide, carbon monoxide and undecane. The formation of by-products, as well as the removal efficiency, were investigated. Zemas temperatūras plazma GOS attīrīšanai dūmgāzēs Šī darba galvenais mērķis bija veikt izpēti zemas temperatūras plazmas lietojumam dūmgāzu attīrīšanā no gaistošajiem organiskajiem savienojumiem (GOS). GOS tiek minēti kā prekursori - vielas, kas veicina piezemes ozona veidošanos, noārda stratosfēras ozona slāni un uzkrājas apkārtējā vidē, kā arī piedalās fotoķīmiskās reakcijās, veido toksiskus un kancerogēnus savienojumus. Tiek uzskatīts, ka zemas temperatūras plazmas tehnologijas nākotnē varētu samazināt emisijas ļoti efektīvi un par saprātīgām izmaksām. Plazma gaisā veido ozonu, kas ir viens no labākajiem oksidētājiem, ar kuru ir iespējams attīrīt GOS līdz CO2 un ūdenim, tāpēc tika apskatītas GOS attīrīšanas iespējas ar plazmu. Tika pētīti galvenie procesi, kas norisinās plazmā. Eksperimentālais stends tika izveidots INP institūtā Greifsvaldē Vācijā. Pētījumā, analizējot plazmas reaktora darbību un ozona veidošanos, tika konstatēts, ka ozona veidošanās procesā slāpekļa oksīdu formēšanās gāzu sastāviem ar un bez GOS bija atšķirīga. Tika noteikts, ka plazmā veidojas ne tikai CO2 un H2O, bet arī daudz dažādi blakusprodukti. Kā galvenos var minēt N2O un skudrskābi. Nepilnīgi oksidējoties rodas arī citi GOS, tomēr izmantojot FTIR spektrometru, to nebija iespējams noteikt, jo notika spektru pārklāšanās. Tika sasniegta 27 % GOS attīrīšanas efektivitāte un piedāvāti risinājumi, kā palielināt šo efektivitāti, nepalielinot reaktora jaudu. Citu GOS veidošanās apstākļu izpētei, kā arī attīrīšanas efektivitātes paaugstināšanai, ir nepieciešami plašāki eksperimentāli pēt ījumi.

Climate Technology in a Wood Chips Boiler House

Climate Technology in a Wood Chips Boiler House One of the innovative solutions of climate technologies is a pilot project relating to the condenser of fuel combustion products which is installed at a chips-fuelled boiler house in the Ludza city. A commercial experiment with the use of a gas condenser has been run at a boiler-house. An empirical model has been obtained, that describes the relation between the specific greenhouse gas (GHG) emissions reduction and the temperature difference of irrigation liquid & condensate mixture. Klimata tehnologijas šķeldas katlu mājā Raksts veltīts vienam no klimata tehnologiju inovatīviem risinājumiem ir kurināmā degšanas produktu kondensatora pilotprojekt s dūmgāzu dziļai dzesēšanai šķeldas katlu mājā Ludzas pilsētā. Dūmgāzu dziļa dzesēšana nozīmē, ka dūmgāzes dzesē zemāk par rasas punkta temperatūru. Šāds nosacījums tehnologiski tiek realizēts tādējādi, ka tiek nodrošināti tādi procesu īstenošanas apstākļi, ka tiek panākta dūmgā zēs esošo tvaiku kondensācija. Šajā gadījumā tiek iegūts siltums, kurš netiek ņemts vērā, nosakot zemāko sadegšanas siltumu, kuru izmanto katl u māju lietderības koeficienta noteikšanā. Ieviests no ekonomisks parametrs: īpatnējais SEG emisiju samazinājuma ieguvums uz sar ažoto siltumenergijas vienību katlu mājā, pateicoties mazākam SEG emisiju apjomam, kas nonāk apkārtējā vidē, un emisiju tirdzniecības dažādiem variantiem Eiropā un pasaulē. Pilotprojekta vietā realizēts uzstādīto tehnologisko iekārtu rūpnieciskais eksperiments, kura laikā savākto datu apstrādes u n regresijas analīzes rezultātā iegūts empīrisks modelis, kas rāda siltumnīcefekta gāzu emisiju samazinājuma ieguvumu atkarību no izsmidzināšanas ūdens temperatūra s starpības, pie kam novērots, ka lielāka šķidruma temperatūru starpbība dod lielāku siltumnīcefekta gāzu emisiju samazinājumu. SEG emisiju samazinājumam noteikšanai izstrādāts modelis, kura algoritmā iestrādāta saikne starp aprēķinu, datu bāžu un eksperimentālo datu moduļiem.

Analysis of Flue Gas Condenser Operation

Analysis of Flue Gas Condenser Operation The paper is devoted to the problems connected with the use of gas condensers in the wood chips-fuelled boilers. To process the relevant data and evaluate the operation of such a gas condenser, a model was created which involves not only the data derived from performance calculations of the energy source but also the data of experimental measurements; besides, the model contains an evaluation module which allows the efficiency of a gas condensers operation and the necessary improvements to be determined. Gāzes Kondensatora Darbības Analīze Kopsavilkums Koksnes šķeldas izmantošanas efektivitātes paaugstināšanas iespējas ir da-žādas: ne tikai tās mitruma samazināšana, bet arī tvaiku kondensācijas siltuma atgūšana gāzes kondensatoros. Rakstā pētītas problēmas, kas ir saistītas ar gāzes kondensatora izmantošanu šķeldas katlu mājās. Izstrādātais datu apstrādes un gāzes kondensatora darbības vērtēšanas modelis ietver gan datus, kas ir iegūti no energo-avota darbības aprēķiniem, gan eksperimentālu mērījumu datus un analīzi, gan arī vērtēšanas moduli, ar kura palīdzību ir iespējams noteikt gāzes kondensatora iekār-tas darbības efektivitāti un potenciālos uzlabojumus. Eksperimentālo datu apstrādes rezultātā iegūts empīrisks modelis, kas lie-cina, ka pieaugot katla jaudai, samazinās īpatnējais iegūtā siltuma daudzums, kas liecina par tukša gāzes kondensatora darbības energoefektivitātes konstruktīviem un siltumapgādes sistēmas ierobežojumiem. Iegūtie rezultāti apliecina, ka iegūtā fiziskā siltuma komponente ir mazāka par kondensācijas procesā saņemto siltum-energiju.

Methods of Nitrogen Oxide Reduction in Pellet Boilers

Methods of Nitrogen Oxide Reduction in Pellet Boilers The main goal of this research was to create and test technical solutions that reduce nitrogen oxide emissions in low-capacity pellet boiler. During the research, wood pellets were incinerated in a pellet boiler produced in Latvia with a rated capacity of 15 kW. During the research two NOx emission reduction methods were tested: secondary air supply in the chamber and recirculation of flue gases. Results indicated a drop of NOx concentration only for flue gas recirculation methods. Maximum reduction of 21% was achieved.

Heat and Mass Transfer Processes in Scrubber of Flue Gas Heat Recovery Device

Heat and Mass Transfer Processes in Scrubber of Flue Gas Heat Recovery Device The paper deals with the heat and mass transfer process research in a flue gas heat recovery device, where complicated cooling, evaporation and condensation processes are taking place simultaneously. The analogy between heat and mass transfer is used during the process of analysis. In order to prepare a detailed process analysis based on heat and mass process descriptive equations, as well as the correlation for wet gas parameter calculation, software in the Microsoft Office Excel environment is being developed.

Influence of Thermo-Dynamic Properties and Thermal Inertia of the Building Envelope on Building Cooling Load

Influence of Thermo-Dynamic Properties and Thermal Inertia of the Building Envelope on Building Cooling Load Buildings are responsible for about 30 % of the total energy consumption of Latvia. Specific heat consumption is 200-225 kWh/m2 per annum, for its part the average consumption of one household is about 1000-1200 kWh per annum. Due to increasing needs for comfort, an increase in the total area of buildings covered by glass, as well as intensified interest in establishing a good microclimate in buildings, there is also increasingly more attention paid on to the cooling load of buildings and the related heat transfer and exchange processes. Thermal inertia and the thermal mass of building envelope are main factors, which substantially influence the amplitude of changes in temperature and the period during which the internal temperature is dependant on the external temperature.

Demand Side Management in Pellet Production: Internal and External Factors

Abstract This paper demonstrates a demand side management case study: how to save energy and how research and data analysis help to create an energy management system in a pellet production facility; and shows ways to implement the EU energy efficiency directive in production facilities. The study carried out in this research serves as a far-reaching step that can be taken to improve energy efficiency during the operation mode of technological equipment. The benchmarking methodology is used for analysis of results. Internal and external factors and indicators, which affect energy management potential in pellet production are analysed. Analysis of external factors is based on the state legal framework regulating the development of the energy sector. Methodology on the analysis of energy demand includes the internal energy management of an enterprise. The experimental results discussed in this paper show that particular steps, which are oriented to specific use of technological equipment, could play significant role in energy efficiency improvement in industry which is illustrated by the pre-milling process in the pellet production system using power.