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[en] Radiation recuperator is a class of indirect contact heat exchanger widely used for waste heat recovery in high temperature industrial applications. At higher temperatures heat loss is higher and as the cost of energy continues to rise, it becomes imperative to save energy and improve overall energy efficiency. In this light, a radiation recuperator becomes a key component in an energy recovery system with great potential for energy saving. Improving recuperator performance, durability, and its design and material considerations has been an ongoing concern. Recent progress in furnace design and micro turbine applications together with use of recuperators has resulted in reduced fuel consumption, increased cost effectiveness and short pay-back time periods. Due to its high commercial value and confidential nature of the industry, little information is available in the open literature as compared to convection recuperators where results are well documented. This review paper intends to bridge the gap in literature and provides valuable information on experimental and theoretical investigations in radiation recuperator development along with identification of some unresolved issues.
[en] The reader will achieve a benchmark understanding of the essence of cleaning for the removal of contaminants from machine elements by means of cryo jet/ water-ice jet with particles prepared beforehand. This paper represents the classification of the most common contaminants appearing on the surfaces of machine elements after a long-term service. The conceptual contribution of the paper is to represent a thermo-physical model of contaminant removal by means of a water ice jet. In conclusion, it is evident that this study has shown the dependencies between the friction force of an ice particle with an obstacle (contamination), a dimensional change of an ice particle in the cleaning process and the quantity of heat transmitted to an ice particle. (paper)
[en] The increase of energy efficiency and energy saving are the main indicators of the improvement and growth of the competitiveness of the Russian economy. One of the system approaches is saving of energy resources through heat recovery. The use of heat recovery units and assessment of the boundaries of their effective use are rather relevant for regions with a long heating period and low negative temperatures. The study proves that special climatic conditions of the Southern Urals provide certain benefits when using heat recovery units in the cold season, relative to other regions, which allows us to use them effectively in ventilation and air conditioning systems throughout the year. (paper)
[en] The economic reasoning of engineers has to include the external costs resulting from the effects of engineering processes. Ways of dealing with these costs have to be found within the framework of the development of market economy systems. In their contribution, the authors present approaches for the specific subject of energy use and provide theories about the engineers' way of thinking and working, in line with the current knowledge about the problems related to the effects of engineering processes. (orig.)
[de]In das wirtschaftliche Denken der Ingenieure ruecken die Sozialen Kosten im Ergebnis von Technikfolgen. Im Rahmen der Entwicklung der marktwirschaftlichen Ordnungen muessen Wege zu ihrer Bewaeltigung begangen werden. Im Beitrag bieten die Verfasser Positionen zur Spezifik der Energienutzung und stellen Thesen zu einem dem heutigen Kenntnisstand der Technikfolgenproblematik entsprechenden Denk- und Arbeitsstil der Ingenieure zur Diskussion. (orig.)
[en] As a part of the project 'development of hydrogen production technologies by high temperature electrolysis using very high temperature reactor', we have developed an electrolyzer model for high temperature steam electrolysis (HTSE) system and carried out some preliminary estimations on the effects of heat recovery on the HTSE hydrogen production system. To produce massive hydrogen by using nuclear energy, the HTSE process is one of the promising technologies with sulfur-iodine and hybrid sulfur process. The HTSE produces hydrogen through electrochemical reaction within the solid oxide electrolysis cell (SOEC), which is a reverse reaction of solid oxide fuel cell (SOFC). The HTSE system generally operates in the temperature range of 700∼900 .deg. C. Advantages of HTSE hydrogen production are (a) clean hydrogen production from water without carbon oxide emission, (b) synergy effect due to using the current SOFC technology and (c) higher thermal efficiency of system when it is coupled nuclear reactor. Since the HTSE system operates over 700 .deg. C, the use of heat recovery is an important consideration for higher efficiency. In this paper, four different heat recovery configurations for the HTSE system have been investigated and estimated
[en] The main objective of the project was to develop a methodology to assess energy savings in the industry. The project has been carried out in collaboration between Risoe National Laboratory and Danish Energy Analysis. The developed methodology, can be used to assess the effects of the introduction of a new energy saving technology in the industry with regard to energy, environment, work environment and economy. The methodology has been developed as a difference model. In this method the differences in energy consumption etc., are estimated for the reference technology and the energy saving technology. The methodology which has been developed during the project has been tested by a firm, who had to decide between two available technological solutions. (EG) 96 tabs., 9 ills., 52 refs
[en] Highlights: • Triplex loop heat pump system for ventilation heat recover is proposed. • Mass flow rate in heat pump system can be improved by triplex loop system. • COP of triplex loop is increase with the decrease of outdoor temperature. • The performance of triplex system is higher than traditional system in most cases. - Abstract: Ventilation heat recovery is an important means of effectively reducing the energy consumption of buildings. To improve the performance of a heat pump heat recovery system under large temperature difference conditions in winter, a triplex loop heat pump system, which contains three independent heat pump cycles, is proposed in place of its single loop counterpart. Operating characteristics and system performance were analyzed while indoor temperature was constant at 20 °C and as outdoor temperature dropped from 15 °C to −20 °C. Results showed that with the decrease of the outdoor temperature, the mass flow rate and temperature effectiveness of the triplex loop heat recovery system decreased whereas the heating capacity and the coefficient of performance (COP) increased. Under the experimental conditions, the COP of the triplex loop system had an advantage over the traditional heat pump system when the outdoor temperature was below 2.5 °C. When the outdoor temperature was −20 °C, the COP of the triplex system could reach 9.33, which was 23.1% higher than that of the traditional system.
[en] The potential for greenhouse gas (GHG) reduction in industry through process integration measures depends to a great extent on prevailing technical and economic conditions. A step-wise methodology developed at the author's department based on pinch technology was used to analyse how various parameters influence the cost-optimal configuration for the plant's energy system, and the opportunities for cost-effective GHG emissions reduction compared to this solution. The potential for reduction of GHG emissions from a given plant depends primarily on the design of the industrial process and its energy system (internal factors) and on the electricity-to-fuel price ratio and the specific GHG emissions from the national power generation system (external factors)
[en] Ultra-low energy buildings focus on realizing ultra-low energy consumption mainly by virtue of passive mode and providing a comfortable indoor environment. Such buildings mainly rely on high-performance envelope, fresh air heat recovery, air tightness, adjustable shade and other building technologies to enable ultra-low energy consumption. However, the difficulty mainly lies in technical suitability. That is, how to meet the energy requirements of heating and cooling under the conditions of non-mechanical, no energy or less energy consumption through reasonable design of key technologies. Combining with the climate characteristics of Beijing, this paper studies the key technologies of ultra-low energy buildings and attempts to make active exploration on the technical advance of ultra-low energy buildings. (paper)
[en] In this study, mean streamline and Computational fluid dynamics (CFD) analyses were performed to investigate the performance of a small centrifugal steam compressor using a latent heat recovery technology. The results from both analysis methods showed good agreement. The compression ratio and efficiency of steam were found to be related with those of air by comparing the compression performances of both gases. Thus, the compression performance of steam could be predicted by the compression performance of air using the developed dimensionless parameters