scholarly journals Energy Savings Analysis for Operation of Steam Cushion System for Sensible Thermal Energy Storages

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 286
Author(s):  
Ryszard Zwierzchowski ◽  
Olgierd Niemyjski ◽  
Marcin Wołowicz

The paper presents an analytical discussion of how to improve the energy efficiency of the steam cushion system operation for a Thermal Energy Storage (TES) tank. The EU’s green deal 2050 target policy requires an increase in the energy efficiency of energy production and use, as well as an increase in the share of renewable energy in the overall energy production balance. The use of energy-efficient TES is considered as one of the most important technologies to achieve the objectives of this EU policy. The analyses presented in the paper of energy-efficient operation of steam cushion (SC) systems were carried out by using operational data received from three District Heating Systems (DHSs) that supply heat and electricity to one of the largest cities in Poland and are equipped with the TES systems. These three analyzed TESs differ in capacities from 12,800 to 30,400 m3, tank diameters from 21 to 30 m and shell height from 37 to 48.2 m. The main purpose of using a steam cushion system in the TES tank is to protect the water stored in it against the absorption of oxygen from the surrounding atmospheric air through the surge chamber and safety valves located on the roof of the tank. The technical solutions presented here for the upper orifice for charging and discharging hot water into/from the tank and the suction pipe for circulating water allow to us achieve significant energy savings in the steam cushion systems. Both the upper orifice and the end of suction pipe are movable through the use of pontoons. Thanks to the use of this technical solution, a stable insulating water layer is created above the upper orifice in the upper part of the TES tank, where convective and turbulent transport of heat from the steam cushion space to the hot water stored in the tank is significantly limited. Ultimately, this reduces the heat flux by approximately 90% when compared to the classic technical solutions of steam cushion systems in TES tanks, i.e., for the upper orifice and circulation water pipe. The simplified analysis presented in the paper and comparison of its results with experimental data for heat flow from the steam cushion space to hot water stored in the upper part of the TES tank fully confirms the usefulness of the heat-flow models used.

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1819
Author(s):  
Slobodan Dudić ◽  
Vule Reljić ◽  
Dragan Šešlija ◽  
Nikolina Dakić ◽  
Vladislav Blagojević

During pneumatic control system design, the critical value for choosing the appropriate pneumatic actuator is the weight of the workpiece. In the case of flexible production systems, which are the core part of the Industry 4.0 (I4.0) concept, the weight of the workpieces is often variable, since the crucial feature of this kind of production is its ability to deal with variable parts. Therefore, in order to deal with the variable weight of parts, a pneumatic actuator is chosen according to the heaviest part. However, according to another I4.0 principle, energy efficient operation of machines, the previous criteria for choosing a pneumatic actuator is energy efficient only when handling the heaviest part. In all other cases, operation of the pneumatic actuator is suboptimal in terms of energy efficiency. Aiming to solve this problem, this paper considers the possibility of using a new pressure regulator instead of traditional manually adjusted pressure regulators. This regulator provides operating pressure modification in real-time in accordance with the weight of the workpieces. In this way, the optimal compressed air consumption is ensured for each workpiece. Implementation of this device has yielded significant energy savings; however, the value is variable and depends on working task characteristics.


Author(s):  
Alexander D. Pisarev

This article studies the implementation of some well-known principles of information work of biological systems in the input unit of the neuroprocessor, including spike coding of information used in models of neural networks of the latest generation.<br> The development of modern neural network IT gives rise to a number of urgent tasks at the junction of several scientific disciplines. One of them is to create a hardware platform&nbsp;— a neuroprocessor for energy-efficient operation of neural networks. Recently, the development of nanotechnology of the main units of the neuroprocessor relies on combined memristor super-large logical and storage matrices. The matrix topology is built on the principle of maximum integration of programmable links between nodes. This article describes a method for implementing biomorphic neural functionality based on programmable links of a highly integrated 3D logic matrix.<br> This paper focuses on the problem of achieving energy efficiency of the hardware used to model neural networks. The main part analyzes the known facts of the principles of information transfer and processing in biological systems from the point of view of their implementation in the input unit of the neuroprocessor. The author deals with the scheme of an electronic neuron implemented based on elements of a 3D logical matrix. A pulsed method of encoding input information is presented, which most realistically reflects the principle of operation of a sensory biological neural system. The model of an electronic neuron for selecting ranges of technological parameters in a real 3D logic matrix scheme is analyzed. The implementation of disjunctively normal forms is shown, using the logic function in the input unit of a neuroprocessor as an example. The results of modeling fragments of electric circuits with memristors of a 3D logical matrix in programming mode are presented.<br> The author concludes that biomorphic pulse coding of standard digital signals allows achieving a high degree of energy efficiency of the logic elements of the neuroprocessor by reducing the number of valve operations. Energy efficiency makes it possible to overcome the thermal limitation of the scalable technology of three-dimensional layout of elements in memristor crossbars.


Author(s):  
Valerio De Martinis ◽  
Ambra Toletti ◽  
Francesco Corman ◽  
Ulrich A. Weidmann ◽  
Andrew Nash

The optimization of rail operation for improving energy efficiency plays an important role for the current and future market of rail freight services and helps rail compete with other transport modes. This paper presents a feedforward simulation-based model that performs speed profile optimization together with minor rescheduling actions. The model’s purpose is to provide railway operators and infrastructure managers with energy-efficient solutions that are tailored especially for freight trains. This work starts from the assumption that freight train characteristics are completely defined only a few hours before actual departure; therefore, small specific feedforward adjustments that do not affect the surrounding operation can still be considered. The model was tested in a numerical example. The example clearly shows how the optimized solutions can be evaluated with reference to energy saved and robustness within the rail traffic. The evaluation is based on real data from the North–South corridor crossing Switzerland from Germany to Italy.


The progressive development of the economy of the Republic of Kazakhstan is impossible without solving the issues of increasing energy efficiency and energy conservation. These issues are very relevant in the construction sector of Kazakhstan. Housing facilities, on average, consume 2-3 times more heat per square meter, than buildings in Europe. However, in Kazakhstan until now there is no methodology for determining the energy efficiency of buildings and structures that meets modern requirements. The methodology discussed in this article is harmonized with EU requirements and establishes a method for calculating the annual energy consumption of buildings for heating, hot water, ventilation and air conditioning, taking into account auxiliary energy for the operation of these systems, and is intended for use in the design of new construction, reconstruction (modernization) residential and public buildings, as well as operated buildings and structures.


2019 ◽  
Vol 116 ◽  
pp. 00107
Author(s):  
Ryszard Zwierzchowski

The paper contains a method for improvement of operation of steam cushion system including its energy savings analyses, for a Thermal Energy Storage (TES) tank. Energy savings analyses were performed using operational data from selected Combined Heat and Power plants, which supply heat to large cities in Poland and are furnished with the TES. The role of the steam cushion system in the TES tank is to prevent the stored water against absorbing oxygen from atmospheric air. In the TES tank, which is a non-pressure tank, oxygen from atmospheric air could penetrate to the network water through the surge chamber and safety valves. The steam pressure under the roof is generated from technological steam injected under the roof. Energy savings in the steam cushion system are generated by using an appropriate technical solution for the upper orifice and suction pipe for circulation water, i.e., to make it movable through the use of pontoons. An isolating buffer layer is created at the top of the tank with very small convective and turbulent heat transport, which causes limited heat transfer from steam bed to the stored water in the tank. This results in heat flux of approximately 10% of the heat flux that occurs in the typical technical solution of the upper orifice and suction pipe for circulation water in the TES tank. This technology offers great opportunities to improve the operating conditions of District Heating System, cutting energy production costs and emissions of pollutants to the atmosphere.


1983 ◽  
Vol 105 (4) ◽  
pp. 681-685 ◽  
Author(s):  
F. Freudenstein ◽  
M. Mayourian ◽  
E. R. Maki

The energy loss in cam-follower systems due to friction between moving parts can be a significant contributor to the power loss in machinery. Considering the total number of cam-operated machines in manufacturing and other operations, the energy savings obtainable by improving the efficiency of the average cam-follower system by even a small percentage would be significant. In this investigation a new rating factor—an energy-loss coefficient proportional to the energy loss at the cam-follower interface—has been defined and evaluated. The rating factor relates to energy efficiency in a manner analogous to the way in which the well-known rating factors for velocity, acceleration, and shock relate to the kinematic characteristics of the cam-follower system. Two cam-follower configurations have been considered: 1) a follower motion governed by both cam and return spring, and 2) a follower positively driven by the cam. In both cases it was found that cam curves with identical rise and rise times can differ substantially in energy efficiency thereby demonstrating the significance of an energy-optimization strategy in the design of cam-follower systems. The nature of the functional dependence of the energy loss on system parameters has been identified and a minimum energy-loss limit established.


2014 ◽  
Vol 1041 ◽  
pp. 105-108
Author(s):  
Anna Sedláková ◽  
Pavol Majdlen ◽  
Ladislav Ťažký

The building envelope is a barrier that separates the internal environment from the effects of weather. This barrier ought to facilitate the optimal comfort of the interior environment in winter as well as summer. It has been shown in practice that most building defects occur within the building envelope. This includes external walls, roofs and floors too, and is impartial to new or renovated buildings. Heat losses of buildings through external constructions – roof, external walls, ground slabs are not negligible. It is therefore important to pay more attention to these construction elements. Basementless buildings situated on the ground are in direct contact with the subgrade and its thermal state. An amount of heat primarily destined for the creation of thermal comfort in the interior escapes from the baseplate to the cooler subgrade. The outgoing heat represents heat losses, which unfavourably affect the overall energy efficiency of the building. The heat losses represent approximately 15 to 20 % of the overall heat losses of the building. This number is a clear antecedent for the need to isolate and minimalize heat flow from the building to the subgrade.


2014 ◽  
Vol 548-549 ◽  
pp. 1815-1819 ◽  
Author(s):  
Xiao Chun Qin ◽  
She Gang Shao ◽  
Yi Shen

Green lighting technology has the advantages of energy efficiency, friendly environment, safety and comfort. Based on the introduction of green lighting technology, taken the Mt. Lushan West Sea tourist highway service as the case study, we analyzed light guide illumination, the optimum use of natural light and energy efficient lighting respectively from the aspects of technical characteristics and the specific highway service application. We finally made the economic analysis in the energy savings of green lights in the highway service, and the result showed that through the use of green lighting systems Mt. Lushan West Sea tourist highway service could save electricity and reduce operating costs 134,700 Yuan per year.


2016 ◽  
Author(s):  
M. T. Nitsas ◽  
I. P. Koronaki ◽  
A. S. Kontos

The scope of this work is the analysis of the electrical and thermal performance of an asymmetric hybrid solar collector PVT and the prospect of the installation of a system consisting of these collectors in the Mediterranean region. For the purpose of this work, the Solarus V11 PVT collector (readily available in our laboratory) was chosen and numerically modeled. The main asset of this collector is its asymmetric reflector that consists of a circular and a parabolic part leading to a maximum thermal energy production even in winter as the solar radiation is concentrated in the edge of the reflector rather than in the center of it. Using a software developed in Matlab, the calculated data are presented for both thermal and electrical energy and they are compared with the hot water and electrical energy requirements (per month) around the Mediterranean territory. Furthermore, a parametric study is conducted in order to investigate the effect of the mass flow rate and the PVT array configuration on the thermal and electrical production, as well as the efficiency of the solar cells of the system. Moreover, in order to increase the PV cell efficiency, nanofluids, i.e. mixtures of nanometer size particles well-dispersed in a base fluid, are proposed as heat transfer fluids and the analysis for the performance evaluation is conducted for different nanoparticle loadings.


2012 ◽  
Vol 3 (1) ◽  
pp. 11-17 ◽  
Author(s):  
J. Frijns ◽  
R. Middleton ◽  
C. Uijterlinde ◽  
G. Wheale

Energy costs and climate change challenges the water industry to improve their energy efficiency. The number of examples of energy measures in water production and treatment is growing rapidly. In this paper, best practices of energy efficiency from the European water industry are presented with the objective of learning from each other. The best practices are collected within the framework of the Global Water Research Coalition's attempt to devise a global compendium ‘Best practices in the energy efficient design and operation of water industry assets’. The case studies in the compendium show significant energy savings in all parts of the water cycle. Examples with potential include the improved operational set up of pumping design, on line aeration control, and energy-efficient bubble aerators and sludge belt thickeners. Next to optimising energy efficiency across the water cycle, there are also opportunities for energy generation. Promising practices include biogas production from sludge (co)digestion and hydraulic energy generation from micro-turbines.


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