scholarly journals Optimal Operation for Integrated Electricity–Heat System with Improved Heat Pump and Storage Model to Enhance Local Energy Utilization

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6729
Author(s):  
Yang Chen ◽  
Yao Zhang ◽  
Jianxue Wang ◽  
Zelong Lu
Keyword(s):  
Variable Mass ◽  
Clean Energy ◽  
Heat Pumps ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Water Tank ◽  
Heat Network ◽  
Heat System ◽  
Guarantee System ◽  
Electricity Network

As the need for clean energy increases, massive distributed energy resources are deployed, strengthening the interdependence of multi-carrier energy systems. This has raised concerns on the electricity-heat system’s co-operation for lower operation costs, higher energy efficiency, and higher flexibility. This paper discusses the co-operation of integrated electricity–heat system. In the proposed model, network constraints in both systems are considered to guarantee system operations’ security: the branch flow model is utilized to describe the electricity network, while a convexified model considering variable mass flow and temperature dynamics is adopted to describe the heat network. Additionally, novel models for heat pumps and the stratified water tank are proposed to represent the physical system more accurately. Finally, to preserve the information privacy of separate systems, a distributed algorithm is proposed based on the alternating direction method of multipliers (ADMM). Numerical studies show that the co-operation could provide a more economical and reliable solution than the decoupled operation of the heat network and electricity network. Moreover, the ADMM-based algorithm could derive solutions very close to the optimum provided by centralized optimization.

scholarly journals Integrated Energy System Configuration Optimization for Multi-Zone Heat-Supply Network Interaction

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3052 ◽  
Author(s):  
Tang Bo ◽  
Gao Gangfeng ◽  
Xia Xiangwu ◽  
Yang Xiu
Keyword(s):  
Programming Model ◽  
Clean Energy ◽  
Energy System ◽  
Collaborative Optimization ◽  
Energy Utilization ◽  
System Capacity ◽  
Mixed Integer ◽  
Heat Network ◽  
Network Interaction ◽  
Integrated Energy System

The integrated energy system effectively improves the comprehensive utilization of energy through cascade utilization and coordinated scheduling of various types of energy. Based on the independent integrated energy system, the thermal network interaction between different load characteristic regions is introduced, requiring a minimum thermal grid construction cost, CCHP investment operation cost and carbon emission tax as the comprehensive optimization targets, and making overall optimization to the configuration and operation of the multi-region integrated energy systems. This paper focuses on the planning of equipment capacity of multi-region integrated energy system based on a CCHP system and heat network. Combined with the above comprehensive target and heat network model, a mixed integer linear programming model for a multi-region CCHP system capacity collaborative optimization configuration is established. The integrated energy system, just a numerical model solved with the LINGO software, is presented. Taking a typical urban area in Shanghai as an example, the simulation results show that the integrated energy system with multi-zone heat-suply network interaction compared to the single area CCHP model improved the clean energy utilization of the system, rationally allocates equipment capacity, promotes the local consumption of distributed energy, and provides better overall system benefits.

Real-time optimal operation of integrated electricity and heat system considering reserve provision of large-scale heat pumps

Energy ◽  
2021 ◽  
pp. 121606
Author(s):  
Menglin Zhang ◽  
Qiuwei Wu ◽  
Jinyu Wen ◽  
Xizhen Xue ◽  
Zhongwei Lin ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Heat Pumps ◽  
Optimal Operation ◽  
Heat System ◽  
Time Optimal

A novel tuned mass-conical spring system for passive vibration control of a variable mass structure

2021 ◽  
pp. 107754632110004
Author(s):  
Sanjukta Chakraborty ◽  
Aparna (Dey) Ghosh ◽  
Samit Ray-Chaudhuri
Keyword(s):  
Variable Mass ◽  
Design Procedure ◽  
Time History ◽  
Tuned Mass Damper ◽  
Water Tank ◽  
Mass System ◽  
Mass Damper ◽  
Linear Spring ◽  
Spring System ◽  
Elevated Water

This article presents the design of a tuned mass damper with a conical spring to enable tuning to the natural frequency of the system at multiple values, as may be convenient in case of a system with fluctuations in the mass. The principle and design procedure of the conical spring in the context of a varying mass system are presented. A passive feedback control mechanism based on a simple pulley-mass system is devised to cater to the multi-tuning requirements. A design example of an elevated water tank with fluctuating water content, subjected to ground excitation, is considered to numerically illustrate the efficiency of such a tuned mass damper associated with the conical spring. The conical spring is designed based on the tuning requirements at different mass conditions of the elevated water tank by satisfying the allowable load bearing capacity of the spring. Comparisons are made with the conventional passive tuned mass damper with a linear spring tuned to the full tank condition. Results from time history analysis reveal that the conical spring-tuned mass damper can be successfully designed to remain tuned and thereby achieve significant response reductions under stiffening conditions of the primary structure, whereas the linear spring-tuned mass damper suffers performance degradation because of detuning, whenever there is any fluctuation in the system mass.

scholarly journals Calculation and Analysis of the Interval Power Flow for Distributed Energy System Based on Affine Algorithm

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 600
Author(s):  
Bin Ouyang ◽  
Lu Qu ◽  
Qiyang Liu ◽  
Baoye Tian ◽  
Zhichang Yuan ◽  
...  
Keyword(s):  
Power Flow ◽  
Load Condition ◽  
Energy Systems ◽  
Energy System ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Distributed Energy ◽  
Low Load ◽  
Distributed Energy System

Due to the coupling of different energy systems, optimization of different energy complementarities, and the realization of the highest overall energy utilization rate and environmental friendliness of the energy system, distributed energy system has become an important way to build a clean and low-carbon energy system. However, the complex topological structure of the system and too many coupling devices bring more uncertain factors to the system which the calculation of the interval power flow of distributed energy system becomes the key problem to be solved urgently. Affine power flow calculation is considered as an important solution to solve uncertain steady power flow problems. In this paper, the distributed energy system coupled with cold, heat, and electricity is taken as the research object, the influence of different uncertain factors such as photovoltaic and wind power output is comprehensively considered, and affine algorithm is adopted to calculate the system power flow of the distributed energy system under high and low load conditions. The results show that the system has larger operating space, more stable bus voltage and more flexible pipeline flow under low load condition than under high load condition. The calculation results of the interval power flow of distributed energy systems can provide theoretical basis and data support for the stability analysis and optimal operation of distributed energy systems.

Evaluation of Energy Efficiency for a CCHP System With Available Microturbine

2007 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Energy System ◽  
Primary Energy ◽  
Economic Benefits ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energetic Efficiency ◽  
Efficiency Evaluation

This paper deals with the problem of energy utilization efficiency evaluation of a microturbine system for Combined Cooling, Heating and Power production (CCHP). The CCHP system integrates power generation, cooling and heating, which is a type of total energy system on the basis of energy cascade utilization principle, and has a large potential of energy saving and economical efficiency. A typical CCHP system has several options to fulfill energy requirements of its application, the electrical energy can be produced by a gas turbine, the heat can be generated by the waste heat of a gas turbine, and the cooling load can be satisfied by an absorption chiller driven by the waste heat of a gas turbine. The energy problem of the CCHP system is so large and complex that the existing engineering cannot provide satisfactory solutions. The decisive values for energetic efficiency evaluation of such systems are the primary energy generation cost. In this paper, in order to reveal internal essence of CCHP, we have analyzed typical CCHP systems and compared them with individual systems. The optimal operation of this system is dependent upon load conditions to be satisfied. The results indicate that CCHP brings 38.7 percent decrease in energy consumption comparing with the individual systems. A CCHP system saves fuel resources and has the assurance of economic benefits. Moreover, two basic CCHP models are presented for determining the optimum energy combination for the CCHP system with 100kW microturbine, and the more practical performances of various units are introduced, then Primary Energy Ratio (PER) and exergy efficiency (α) of various types and sizes systems are analyzed. Through exergy comparison performed for two kinds of CCHP systems, we have identified the essential principle for high performance of the CCHP system, and consequently pointed out the promising features for further development.

Optimal Scheduling Method of Controllable Loads in DC Smart Apartment Building

2015 ◽  
Vol 16 (6) ◽  
pp. 579-589 ◽  
Author(s):  
Tsubasa Shimoji ◽  
Hayato Tahara ◽  
Hidehito Matayoshi ◽  
Atsushi Yona ◽  
Tomonobu Senjyu
Keyword(s):  
Power Flow ◽  
Residential Buildings ◽  
Heat Pumps ◽  
Optimal Operation ◽  
Optimal Scheduling ◽  
Electricity Pricing ◽  
Residential Areas ◽  
Electricity Cost ◽  
Pricing Scheme ◽  
Scheduling Method

Abstract From the perspective of global warming suppression and the depletion of energy resources, renewable energies, such as the solar collector (SC) and photovoltaic generation (PV), have been gaining attention in worldwide. Houses or buildings with PV and heat pumps (HPs) are recently being used in residential areas widely due to the time of use (TOU) electricity pricing scheme which is essentially inexpensive during middle-night and expensive during day-time. If fixed batteries and electric vehicles (EVs) can be introduced in the premises, the electricity cost would be even more reduced. While, if the occupants arbitrarily use these controllable loads respectively, power demand in residential buildings may fluctuate in the future. Thus, an optimal operation of controllable loads such as HPs, batteries and EV should be scheduled in the buildings in order to prevent power flow from fluctuating rapidly. This paper proposes an optimal scheduling method of controllable loads, and the purpose is not only the minimization of electricity cost for the consumers, but also suppression of fluctuation of power flow on the power supply side. Furthermore, a novel electricity pricing scheme is also suggested in this paper.

Abandoning Peat in a City District Heat System with Wind Power, Heat Pumps, and Heat Storage

2021 ◽  
Author(s):  
Nima Javanshir ◽  
Sanna Syri ◽  
Antti Teräsvirta ◽  
Ville Olkkonen
Keyword(s):  
Wind Power ◽  
Heat Storage ◽  
Heat Pumps ◽  
Heat System ◽  
City District

scholarly journals Dynamically structured bubbling in vibrated gas-fluidized granular materials

2021 ◽  
Vol 118 (35) ◽  
pp. e2108647118
Author(s):  
Qiang Guo ◽  
Yuxuan Zhang ◽  
Azin Padash ◽  
Kenan Xi ◽  
Thomas M. Kovar ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Granular Materials ◽  
Fluidized Beds ◽  
Gas Flow ◽  
Scale Up ◽  
Clean Energy ◽  
System Size ◽  
Optimal Operation ◽  
Constitutive Relationship ◽  
Energy Processes

The dynamics of granular materials are critical to many natural and industrial processes; granular motion is often strikingly similar to flow in conventional liquids. Food, pharmaceutical, and clean energy processes utilize bubbling fluidized beds, systems in which gas is flowed upward through granular particles, suspending the particles in a liquid-like state through which gas voids or bubbles rise. Here, we demonstrate that vibrating these systems at a resonant frequency can transform the normally chaotic motion of these bubbles into a dynamically structured configuration, creating reproducible, controlled motion of particles and gas. The resonant frequency is independent of particle properties and system size, and a simple harmonic oscillator model captures this frequency. Discrete particle simulations show that bubble structuring forms because of rapid, local transitions between solid-like and fluid-like behavior in the grains induced by vibration. Existing continuum models for gas–solid flows struggle to capture these fluid–solid transitions and thus cannot predict the bubble structuring. We propose a constitutive relationship for solids stress that predicts fluid–solid transitions and hence captures the experimental structured bubbling patterns. Similar structuring has been observed by oscillating gas flow in bubbling fluidized beds. We show that vibrating bubbling fluidized beds can produce a more ordered structure, particularly as system size is increased. The scalable structure and continuum model proposed here provide the potential to address major issues with scale-up and optimal operation, which currently limit the use of bubbling fluidized beds in existing and emerging technologies.

scholarly journals SOLAR ENERGY: A POTENTIAL SOURCE OF RENEWABLE AND CLEAN ENERGY

2018 ◽  
Vol 6 (8) ◽  
pp. 214-217
Author(s):  
Deepak Aryal
Keyword(s):  
Solar Energy ◽  
Urban Areas ◽  
Sunshine Duration ◽  
Winter Season ◽  
Clean Energy ◽  
Energy Utilization ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
Solar Energy Utilization ◽  
Analytical Review

This paper reports analytical review results on the global and national importance of solar energy as a clean and renewable source of energy. Pre-monsoon and post monsoon seasons have higher mean monthly sunshine duration (about 8 hours/day) than summer (about 5 hours/day) and winter (about 7 hours/day) seasons in Kathmandu. The lowest sunshine duration during summer season is attributed to the effect of monsoonal clouds during that period. Pre-monsoon and monsoon seasons receive solar energy of about 250 W/m2 and 200 W/m2 respectively. The winter season receives the least amount of solar radiation (about 150 W/m2). Results show high prospect of solar energy utilization both in rural and urban areas of Nepal.

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