Refrigeration for the cold storage of perishable foods has been utilized for more than a century. The need for refrigerated storage grows with hot weather. The frozen food industry expanded many times in freezer storage in a few decades after World War II. Cold storage facilities are also significant energy consumers that call for attention to thermal behavior as it greatly influences the cost. Proper design to improve thermal behavior of a refrigerated space requires the knowledge of air distribution and thermal conditions within the space. The frozen food quality is sensitive to both storage temperature and fluctuation in temperature. The present work made use of a computational fluid dynamics technique to adequately predict the cold storage airflow pattern variations within the cold room under various evaporator’s arrangements of sizes, numbers and positions. Design parameters included local temperatures and velocity distributions inside a large cold store using standard k-e model with mesh element 5,400,000 tetrahedral cells. Different optional designs utilizing different number of evaporators were investigated as well as the locations of these evaporators according to load estimation of the cold store.

With an overwhelming push for “green” renewable energy in the recent years, the American Society of Mechanical Engineers (ASME) Performance Test Codes (PTCs) are being called upon to develop standards for testing solar power facilities. To meet the challenge, ASME formed a committee to develop PTC 52, Performance Test Code on Concentrated Solar Plants. It was recognized early on by the PTC 52 committee that there is a critical need in the power generation industry to develop a commercial grade test method for the measurement of Total Solar Field Direct Normal Insolation (TSFDNI) that may be used for performance testing. The TSFDNI measurement is important because it is the fuel source (input) for solar power technologies, and is therefore a primary measurement parameter that enters into the solar-to-thermal conversion efficiency calculations. To meet the recognized need, ASME engaged McHale & Associates, Inc. (McHale) in a research project to investigate a solution to this issue so that the industry may be provided with guidelines that can be included in ASME PTC 52 for the accurate determination of TSFDNI. The product of this effort is a conceptual measurement technique, or method, that utilizes a combination of currently available terrestrial point measurements, aerial photography, and pixel contrast recognition software that allows for a visualization of the entire solar field to provide an accurate determination of TSFDNI by “filling in the gaps” between the point measurements while keeping the number of terrestrial point measurements practical. This paper will illustrate the conceptual TSFDNI measurement technique and how it can effectively combat the issues associated with performance testing on days when the field may see areas of haze, dust, aerial obstructions with shadows, or cloudiness which are not visible from the ground by the testing personnel or unavoidable by commercial/contractual constraints; thus allowing performance testing to be conducted on partially cloudy days which would allow facilities to be commercially accepted with confidence at an earlier date than if they had to wait for a “clear solar day”. Guidance on the best practices for deployment in a grid style system in combination with an aerial photography pixel analysis method will be presented along with discussion on how the method will result in acceptable predicted error of the TSFDNI measurement through reducing error associated with the spatial components of the field measurements. This paper will further discuss how this method can be used beyond performance testing by providing the key boundary information for performance models, performance monitoring systems, dispatch models, etc. Ultimately the paper will not only present just how important this measurement technique is for the development of ASME PTC 52, but also to the industry and technology itself, by presenting a way to overcome the current industries short falls in accurately determining TSFDNI.

In 2004, North Omaha Station Unit 1 (NOS 1) experienced multiple condenser vacuum upsets. At least one of them resulted in a unit trip. The upset conditions occurred over relatively short periods of time with no clear indication of the initiating mechanism. Overall, condenser vacuum was low. Various methods were employed to combat the vacuum issues and upset conditions. These included operating both sets of holding steam jet air ejectors (SJAEs) above 600 psig (50% above design), using the hogging SJAE during unit operation and, operating the condensate pumps in a recirculating mode. Air inleakage was a known problem on NOS 1. The air inleakage was no longer measurable since it exceeded the scale of the installed instrumentation (20 scfm). Besides air inleakage, tube fouling of the condenser tubes was also contributing to degraded condenser vacuum. NOS 1 had a history of fouling due to calcium carbonate plateout on the condenser tubes. During the January 2005 outage, major sources of air inleakage were identified and fixed. Leaking tubes in the SJAE intercondenser/aftercondenser were plugged. The condenser tubes were scraped to reduce fouling. Although condenser vacuum improved, problems persisted at low loads. Following a vacuum upset in June 2005, the hogging SJAE was placed into service. Helium testing in July 2005 indicated high air inleakage. The problems continued to persist and, in February 2006, the unit tripped on low condenser vacuum. At that time, the unit had been operating at about 58 Mwe. In order to maintain the unit on line at a reduced load of 40 Mwe, both the hogging SJAE and one set of first stage and second stage holding SJAEs had to be deployed. An attempt to remove the hogging SJAE from service was unsuccessful since it resulted in rapid decrease in air-removal capability of the holding SJAEs. This paper describes the methodology used to troubleshoot the condenser vacuum issues for NOS 1 and remedies proposed for proper performance and reliable operation.

Climate change is a very important environmental, social and economic global problem. During the last century, the Earth’s average surface temperature rose by around 0.6°C. Evidence is getting stronger that most of the global warming that has occurred over the last 50 years is attributable to human activities. Human activities that contribute to climate change include the burning of fossil fuels because it causes emissions of carbon dioxide (CO 2 ), which is the main gas responsible for climate change. In order to bring climate change to a halt, global greenhouse gas emissions would have to be reduced significantly. The European Union (EU) is engaged in international efforts to combat climate change. The EU is also taking serious steps to address its own greenhouse gas emissions. In March 2000 the Commission launched the European Climate Change Programme (ECCP). The ECCP led to the adoption of a range of new policies and measures, among which the EU’s emissions trading scheme, which started its operation on 1 January 2005, will play a key role. In this paper, we want to shortly explain the mechanisms of the Kyoto Protocol, paying particular attention to the Emission Trading. We want to illustrate the European directive and the consequent Italian one: we will explain the Italian implementing norms that have been emitted for the period 2005–2007 and 2008–2012. Limiting then the analysis to the sector of electricity production, we want to show some examples of Italian power plants: we will illustrate them and we will estimate their CO 2 emissions (according to a typical annual operation). The emission levels will be compared with CO 2 quotas assigned in the period 2008–2012: these results will be commented in terms of the unavoidable economic implications that such allocation will involve. The CO 2 quotas, assigned to Italy already for the period 2005–2007, involve a large control of these emissions: such situation will be reflected unavoidably on the increase of the kWh cost (it is already particularly high in comparison with the European average because of the particular energetic mix on which our electricity production is based): these effects could be particularly heavy for the competitiveness of our production system and for the modernization and the widening of our power plant park.

The European Union is 450 million citizens in 25 otherwise sovereign countries, but connected in a multinational federal metastate that claims a combined economy in excess of $9 trillion (US), making it one of the world’s largest economies. As a community faced with massive decontamination and re-industrialization from devastating wars, Europe places due emphasis on issues of environmental sustainability and pollution prevention. Under broad policy guidelines of the New Approach and Integrated Product Planning frameworks, the European Commission is drafting legislation that will mandate eco-standards for all energized end-use equipment for sale in the internal market. These proposed standards may raise controversy in many industry sectors and international arenas (including within Europe itself) because they may not be based on sound and accepted scientific analysis, because they may constitute a de-facto violation at least in spirit of the Technical Barriers to Trade Agreement, and because nobody can yet predict their cost impact and other market effect. Compliance with these emerging energy efficiency regulations will impose considerable management requirements on manufacturers as they devise documentation and certification programs for their products that are likely to be of a scope similar to ISO 14000. This paper assesses the new requirements from a product and design management perspective.

As the power industry is deregulated, the cost of power plays a major role in obtaining long-term Power Purchase agreements. More and more plants, now, are developed with Dry Cooling System for condensing steam from the steam turbine of combined cycle plants or coal-fired plants. However, Dry Cooling has become synonymous with lower plant output. This paper presents solutions to dispel that myth. 1. Options available for control of the air-cooled system, their initial cost and the impact on minimizing internal power consumption and maximizing plant power output. 2. The air-cooled condenser operates normally at high turbine exhaust pressures during high ambient temperatures. The high backpressure results in lower turbine efficiency and lower plant output. Various options available are presented to combat this deficiency to maximize power output.