scholarly journals Building's heat potential on resources in respect to CO2 emissions and primary energy reduction (Case study)

2021 ◽  
Vol 1203 (2) ◽  
pp. 022139
Author(s):  
Frantisek Vranay ◽  
Zuzana Vranayova ◽  
Anna Lis
Keyword(s):  
Slovak Republic ◽  
Renewable Energy Sources ◽  
Primary Energy ◽  
Heat Pumps ◽  
Supply System ◽  
Heating Process ◽  
Main Hypothesis ◽  
Energy Supply System ◽  
Human Thermal Comfort ◽  
Heat Potential

Abstract An increased utilization of renewable energy sources for heating and electricity generation is one of the main tasks of the Slovak Republic. The main hypothesis is that heat pumps are very energy-efficient, and therefore environmentally benign, while providing heating and cooling in many applications. Within good conditions, the energy from low-positional heat, in other way unusable, is used to supply the energy for heat pumps. The paper confirms the applicability of such systems for long term (about 25 years). A building in Košice was used as the model of the transformation of a common office object into the character of a green and energy active one with the target programme being a sustainable building with zero balance of the energy from the network. From the comparison of the past and present operation data of the building, it is possible to show the big advantage of the usage of the heat pump water-water to the energy supply system. At favourable technical conditions in a heat supply system, it becomes the most advantageous solution in achieving today’s targets - minimum emission production combined with investment, low operating costs and achieving necessary human thermal comfort. The convenience of the system increases as it can switch between the cooling and heating process according to conditions. For the whole observed period, the energy consumption is reduced by 70%, the primary energy decreased by 69% compared to 1996 and CO2 emissions were reduced by 98%. The simulations of the object were performed and verified based on the measured data.

scholarly journals The possibility of achievement of the nZEB state of a refurbished detached house powered solely by renewable energy sources in Southern Poland

2018 ◽  
Vol 70 ◽  
pp. 01001
Author(s):  
Jacek Biskupski
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Primary Energy ◽  
Heat Pumps ◽  
Space Heating ◽  
Zero Energy ◽  
Electricity Grid ◽  
Primary Energy Demand ◽  
Pv Generator

This paper gives a thorough description of the two different scenarios of retrofit of an existing detached country house (with high primary energy demand) to a net zero energy building (nZEB) or near zero energy (nearZEB) by using energy form on-site RES. Using a designed piece of modelling software author pointed out two possible solutions. First one, based on a bio boiler and small on-site PV generator (on-grid) and the other based on large PV generator and three heat pumps. A 24 months test was performed in order to find out the output of both scenarios. In first period, the bio boiler delivered energy for space heating and DHW, while energy from PV was used to cover all electricity needs of the household during the 12 months testing period. In the later, the energy received from 10 kWp PV of was partly used to cover the current needs of the entire household (switchable on/off-grid system), and surplus was stored in the national electricity grid and regained later in the winter for the space heating (by a GSHP) and ventilation (ASHP) and DHW (dedicated ASHP). In both cases the system proofed the possibility to achieve the nZEB (nearZEB in first scenario) state of the household, as all (in the first near all) energy needs were covered by renewable energy produced on-site.

scholarly journals Technical-Economic Analysis of a Hybrid Thermal Energy Supply System Based on Renewable Energy Sources

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 19
Author(s):  
Roxana Pătrașcu ◽  
Constantin Ionescu ◽  
Mihai Rareș Sandu ◽  
Diana Ban (Tuțica)
Keyword(s):  
Economic Analysis ◽  
Thermal Energy ◽  
Economic Performance ◽  
Performance Indicators ◽  
Energy Supply ◽  
Renewable Energy Sources ◽  
Supply System ◽  
Negative Effects ◽  
Energy Supply System ◽  
Sensibility Analysis

The technical-economic analysis represents a decisional factor in the implementation of a new thermal energy supply system and is a key part of the feasibility study. In the present paper, the economic performance indicators, used as evaluation instruments within the analysis, highlight the economic efficiency of each proposed scenario and offer an establishment of hierarchy for them. Based on this analysis, the optimal scenario can be recommended, such that the benefits are maximized. The sensibility analysis, performed for the optimal scenario at the end of the paper, shows an estimation of the effects throughout the lifespan of the new system. This is beneficial to pre-empt negative effects or to stimulate the factors that can increase the efficiency of the system throughout the entire lifespan.

scholarly journals Modelling and Simulation of Energy Supply System of Photovoltaic Hybrid RTG Cranes

2020 ◽  
Vol 01 ◽  
Author(s):  
Feiyu Li ◽  
Wangqiang Niu ◽  
Dawei Chen
Keyword(s):  
Diesel Engine ◽  
Energy Supply ◽  
Control Method ◽  
Renewable Energy Sources ◽  
Supply System ◽  
Photovoltaic System ◽  
Energy Supply System ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point

Background: In marine ports, the task of loading, unloading, and stacking containers is generally completed by rubber-tired gantry (RTG) cranes. How to make the RTG cranes work efficiently and reduce their emissions is a hot research topic. Objective: In view of the fact that current RTG cranes still needs a large capacity of diesel engine for energy supply, renewable energy sources, such as solar energy, are introduced to reduce further the capacity of the diesel engine. Method: A photovoltaic hybrid power supply system for RTG cranes is proposed. A MATLAB/Simulink simulation model for the crane with a 10kW solar panel is built, and a power predictive control method is proposed to realize maximum power point tracking (MPPT). The power variation of photovoltaic panels under different irradiance is studied. Results: The simulation results show that the proposed MPPT control method is better than the other two perturb and observe methods. When the irradiance changes cause the photovoltaic output to vary, the lithium battery changes its output correspondingly to compensate for the photovoltaic change, and the load power is still met. The capacity of the diesel engine is 40 kW which is smaller than the former 50 kW one. Based on the irradiance condition in Shanghai, China, the RTG crane can have an 11.4 % fuel reduction yearly by introducing the photovoltaic system. Conclusions: The results show that it is feasible to add the photovoltaic system into the RTG crane, which can reduce the capacity and emissions of the diesel engine.

Integrated Study of a Minimum Exergy Destruction Building Conditioning System

2013 ◽  
Author(s):  
Fabrizio Ferraro ◽  
Enrico Sciubba ◽  
Claudia Toro
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Comfort Level ◽  
Model Case ◽  
Ground Source Heat Pumps ◽  
Energy Supply System ◽  
San Lorenzo ◽  
Heating And Cooling

The relatively low average conversion efficiency of air-conditioning systems and the recently imposed upper bounds to the final energy use in the heating and cooling of residential buildings suggest to consider new approaches to design less energy intensive systems. An integrated, exergy-based approach for the optimal matching of internal and external heating plants in building conditioning systems has been proposed — and its theoretical basis discussed — in a previous paper. The procedure allows the designer to obtain a pseudo-optimal integration of the building and its heating plant (heating element + primary energy supply system) and to identify, among a set of alternative solutions for the building under examination, the thermodynamically most efficient plant. The objective of this paper is to validate the method on a real building in order to demonstrate its practical applicability. The large “Chiostro Hall” (220 square meters, 1245 cubic meters) of the Engineering School of the University “Sapienza” of Roma has been employed as the benchmark. This is the main hall of the building, reconverted from a previously existing Renaissance structure, the old convent of San Lorenzo in Panisperna, which was in turn built on the ruins of a pre-christian roman basilica and of a portion of emperor Nero’s Domus Aurea. The hall consists of two semi-connected rooms, originally the Refectory of the old Convent, that are now used for public events, conferences and graduation ceremonies. This structure can be considered as a model case for similar halls in historical buildings, so that the guidelines deriving from the present study can be extended to other similar environments. The current heating elements are traditional radiators: in our simulations, they have been successively replaced by other elements such as floor and ceiling heating panels and fan coils. Each one of these configurations (the hall and its heating elements) has been modeled and simulated via a commercial CFD code to generate detailed thermal maps and to compute the actual thermal load. Different global “heating chains” were then modeled by coupling solar and hybrid photovoltaic-thermal (PV/T) panels with radiant panels and ground-source heat pumps with fan coils and radiant heating panels. Finally by means of a process simulator software each one of these configurations was analyzed to identify the one that provides the same comfort level with the least exergy use. The procedure also allows to calculate the savings obtained in terms of primary resources.

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