Power Plant In Finland Research Articles

Hydraulically Powered Wood Chip Blower in Test and Its Use Opportunity in Biofuel Supply Chain

Most forest chips are delivered to large-sized, combined heat and power plants in Finland. In this study, we introduce and demonstrate the small-scale delivery of forest wood chips to potential clients, with the wood chips being delivered in a container truck and pneumatically blown into a storage facility. This arrangement of wood chips being blown through a pipe into a storage eliminates the ground handling while requiring a relatively small space. In the demonstration tests, we tested the volumetric flow of biomass in the hose and its noise level while the blower was blowing the material and the flow speed of the material in the hose. This study discusses the test conditions in which the compatibility and suitability of the truck and its hydraulic system were used in conventional chip delivery in Finland and the selected blower type was investigated. According to the results, the biomass volume flow was higher (~0.46 m3/min) when the blower revolution was lower (2392 - 2566 RPM). However, when the RPM was increased to ~3000, the volumetric flow decreased to ~0.24 m3/min. Similarly, the speed of the chips was higher with a lower RPM; 29.9 m/s at an RPM of 2400 and 25 m/s at an RPM of 2700. This is potentially due to both the blower and screw conveyer using the same power source. Additional optimization research would be needed to conclusively state the root cause of this phenomenon. On the other hand, chips from pruned stems had better flow than the chips from whole trees, since chips from whole tree have a wider range of chips sizes, including 1.3% of chips being in the range of 31.5 - 40 mm. The larger chips clogged the hose, which hindered the flow. Finally, the noise tests showed that it was louder at 0 degrees, which contrasted with the situation for the blower, with an aside at 90 degrees.

METHOD FOR DETECTING AGING RELATED FAILURES OF PROCESS SENSORS VIA NOISE SIGNAL MEASUREMENT

In this article we examine the methods for detecting and predicting aging related process sensor failures by analyzing the noise of the sensor output signal. The study uses data from non-differential and differential pressure transmitters used in the pressure and water level measurements of the reactor pressure vessels of units 1 and 2 of the Olkiluoto nuclear power plant in Finland. The article contains a review of the current methods for detection of sensor failures. Additionally, we present a new method for detecting changes in the sensor output signal. The method creates fingerprints of the power spectra of the sensors by using Principal Component Analysis (PCA). The changes in these fingerprints together with the measurements of the redundant sensors can be used to detect indications of some of the impending sensor failures. In the experimental study we are able to produce stable fingerprints for both the non-differential and differential pressure transmitters. Also, a potential failure in one of the differential pressure transmitters in Olkiluoto unit 2 is detected by inspecting the fingerprints and analyzing the spectral changes of the transmitter output signal.

Economic efficiency of the energy wood chip supply chain from Russian Karelia to Finland

ABSTRACTThe development of modern cut-to-length forest harvesting techniques, the availability of non-industrial wood resources, and Russian customs policy have created favorable conditions for the export of wood chips to biomass-based power plants in Finland. Cost of transportation is paramount to the financial feasibility of the bioenergy business, especially long-distance transportation costs. Therefore, the efficiency and costs of cross-border transportation of wood chips were analyzed. The results were compared with the efficiency and costs of transportation of wood chips of Finnish origin. Truck drivers working in the cross-border transportation of wood chips were also interviewed to determine the factors that affect the efficiency of wood chip transportation. The results showed that the highest transportation costs for an 80-km reference distance were those within Finland, at €5.6/m3 loose wood chips, compared to a cross-border route cost of €3.5/m3 loose wood chips. Thus, the proportion of transportation costs to the total supply cost was slightly higher in cross-border transportation (24%) than in Finland (23%) and in Russia (19%). Furthermore, bad road conditions on the Russian side, idle time at the border and the current working schedule of the border crossing point were recognized by truck drivers as the main factors that decreased the efficiency of cross-border transportation.

Exposure to biological and chemical agents at biomass power plants

The increasing use and production of bioenergy means that the number of employees working in this area will inevitably grow, making it ever more important to know the health and safety issues involved in the biomass supply chain. Our aim was to determine the exposure of employees to biological and chemical agents during various work tasks at different biomass-fuelled power plants in Finland. The study included technical surveys on biomass operations and occupational measurements at three CHP plants. Workers’ main health risks were bacteria and fungi, which were easily spread to the air during heavy biomass processes. The exposure levels of actinobacteria, bacterial endotoxins and fungi were high, especially during the unloading of peat and wood chips. In addition, workers were exposed to mechanical irritation caused by organic dust, and chemical irritation caused by volatile organic compounds and components of diesel exhausts. Multiple exposures to these agents may simultaneously have synergistic health effects on workers’ lower and upper respiratory tracts. During operations, workers were also exposed to endotoxins, actinobacteria and fungi, especially during the cleaning and handling of wood chips in silos and while working near screens or crushers. The measured concentrations exceeded the limit values proposed for these agents. The highest concentration of volatile organic compounds was found near conveyors. On the basis of these measurements, we suggested best practices for the power plants. The levels of biological agents in outdoor measurements reflected only low spreading of contaminants from power plants to the environment.

Safety culture and subcontractor network governance in a complex safety critical project

In safety critical industries many activities are currently carried out by subcontractor networks. Nevertheless, there are few studies where the core dimensions of resilience would have been studied in safety critical network activities. This paper claims that engineering resilience into a system is largely about steering the development of culture of the system towards better ability to anticipate, monitor, respond and learn. Thus, safety culture literature has relevance in resilience engineering field. This paper analyzes practical and theoretical challenges in applying the concept of safety culture in a complex, dynamic network of subcontractors involved in the construction of a new nuclear power plant in Finland, Olkiluoto 3. The concept of safety culture is in focus since it is widely used in nuclear industry and bridges the scientific and practical interests. This paper approaches subcontractor networks as complex systems. However, the management model of the Olkiluoto 3 project is to a large degree a traditional top-down hierarchy, which creates a mismatch between the management approach and the characteristics of the system to be managed. New insights were drawn from network governance studies.

Reed canary grass transportation costs – Reducing costs and increasing feasible transportation distances

Reed canary grass is used in several heat and power plants in Finland and it is estimated that about 70–80 plants could utilise reed canary grass as a co-firing fuel. Long-distance transport of reed canary grass forms a significant share of the production and delivery costs. Reed canary grass can be transported in bales or as loose matter. The density of the matter and shape of the bales influence the load-size and the cost. At present it is impossible to obtain the full load-bearing capacity of a lorry even with bales, and with light bulk matter the obtainable load is less than one-third of the load-bearing capacity of a lorry. By using Orkel local-baler it has been possible to obtain the largest load-sizes, but the total economy of the chain is not very good because the baling and chopping of bales increase the total costs. If a full load-bearing capacity of a lorry (30–40 tonne) would be obtained, the transportation costs would be reduced significantly compared to the present situation. Second alternative would be to mix reed canary grass with wood chips or peat before long-distance transport. At the moment feasible transportation distances are relatively short. With briquettes the cargo space could be used more efficiently and the load-size of the transport could be increased.

Cognitive mapping approach analyzing societal decision‐making

Cognitive mapping (CM) approach is reviewed, and the method is applied in analyzing an important case of societal decision‐making. It is shown that CM is an effective way of representing argumentation, consequences, and the linkage between the concepts. The method integrates causal modelling and rational choice theory with parts of cognitive psychology. CM allows for a systematic arguing of issues. The decision‐making problem described here concerns building a new nuclear power plant in Finland. There occurred strong proponents representing mainly the industry and technocratic and engineering experts, and an equally strong resistance represented by ordinary citizens, parliamentarians, and experts. The argumentation went ten years pro and cons before the parliament in 1993 decided against building the proposed nuclear power plant. It gives an ideal case to study the argumentation and contradictions there in as a whole by developing and applying a cognitive mapping approach.

Use of numerical simulation computer codes to fire problems in nuclear power plants in Finland

Zone and field model codes are used for fire simulations, including nuclear facilities, in Finland. Here two examples are described: (a) calculation of evaporation rate of a pool fire (8 MW) in a compartment using FIRST, and calculation of an oil spill fire (180 MW) in a turbine hall using PHOENICS.

Artificial radioactivity in fuel peat and peat ash in Finland after the Chernobyl accident.

The accident at the Chernobyl nuclear power plant in April 1986 caused very uneven deposition of radionuclides in Finland. The deposited radionuclides were found in relatively high concentrations in fuel peat and especially in peat ash because a thin surface layer of peat-production bogs was extracted as fuel peat soon after the fallout occurred. Concentrations of artificial radionuclides in fuel peat and peat ash were measured at six peat-fired power plants in Finland throughout the heating season 1986-87. Concentrations of 137Cs in composite peat samples varied between 30 and 3600 Bq kg-1 dry weight and in ash samples between 600 and 68,000 Bq kg-1. High concentrations in peat ash caused some restrictions to the utilization of peat ash for various purposes.

A possible finnish alternative

A modified Loviisa 1 & 2 plant, with a VVER-440 type of PWR, was designed to be an alternative for the fifth nuclear power plant in Finland. The designed plant is equipped with a full pressure double containment. The safety systems are in three separated safety trains. The plant will have one 500 MWe turbine. The newest design criteria were applied in the design.

Computer Assisted Energy Policy Analysis in the Parliament of Finland

A decision aid developed for members of the Parliament was used to evaluate the desirability of a new big nuclear power plant in Finland. The decision analytic approach was positively received by the politicians. It also helped to structure the public debate on nuclear power in the media. The project showed that decision aids can be very useful in public policy issues if they are introduced early into the decision-making process.

Construction of Atomic Power Plant in Finland

Construction of Atomic Power Plant in Finland