scholarly journals Analysis of the Combined Ice Storage (PCM) Heating System Installation with Special Kind of Solar Absorber in an Older House

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3878 ◽  
Author(s):  
Peter Sivák ◽  
Peter Tauš ◽  
Radim Rybár ◽  
Martin Beer ◽  
Zuzana Šimková ◽  
...  

The energy storage field is nowadays a highly ranking topic. This research deals with the installation and analysis of the ice storage system which combines heat pump, solar absorber, and ice storage tank (phase change material—PCM). This system uses a special kind of solar absorber – header pipes (HDP), which have no thermal isolation compared to the common solar absorber. Thanks to that the HDP, pipes can absorb thermal energy not only from the sun but also from the environment. The rain or snow also affects heat exchange. All that is provided by one technical device. The system can store thermal energy gained from the solar absorber into the ice storage tank for future usage. Research works with data from the real operation, for a period of the year covering all working phases/modes of the system. The analysis of the data led to the identification of several specific modes of the system, especially from the processes taking place in the PCM storage tank during its charging and discharging at various time stages of operation of the whole system. The installation and analysis of the ice storage system probably took place for the first time in Slovakia and Slovak Republic’s conditions. Besides, this system was not installed on a new low-energy house, but on an older family house with thermal insulation. The aim of this installation was also to demonstrate the usability of the ice storage system in an older house and potentially reduce the homeowner’s fees thanks to new technology with higher efficiency. We managed to comprehensively analyze and describe the operation of this system, which also appears to be highly efficient even in a family house with a lower energy certificate, than today’s new low-energy buildings. The results showed a significant efficiency difference in favor of the ice storage system compared to conventional heating systems. The total analysis time was 1616 h and the total efficiency of this heating system—the seasonal coefficient of performance (SCOP) was 4.4. Compared to the average SCOP 3.0 of conventional heating systems for new low-energy houses, the total efficiency increased by 46.6%. These results could therefore be considered as beneficial, especially if we take into account that this system was installed on an approximately 40-year-old family house. The analyzed ice storage system is still working today. The main goals of this paper were to describe the heat pump’s duty cycle with ice storage (PCM) based on real-life data and bring a detailed description of the heat transfer medium behavior at various phases of storing/utilizing heat in the vertical ice storage’s profile for increasing efficiency.

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1832 ◽  
Author(s):  
Janar Kalder ◽  
Andres Annuk ◽  
Alo Allik ◽  
Eugen Kokin

This article describes a method for increasing the solar heat energy share in the heating of a dwelling. Solar irradiation is high in summer, in early autumn, and in spring, but during that same time, the heat demand of dwellings is low. This article describes a solution for storing solar heat energy in summertime as well as the calculations of the heat energy balance of such a storage system. The solar heat energy is stored in a thermally insulated water tank and used in the heating period. The heat is also stored in the ground if necessary, using the ground loop of the heat pump if the water tank’s temperature rises above a certain threshold. The stored heat energy is used directly for heating if the heat carrier temperature inside the tank is sufficient. If the temperature is too low for direct heating, then the heat pump can be used to extract the stored energy. The calculations are based on the solar irradiation measurements and heating demand data of a sample dwelling. The seasonal storing of solar heat energy can increase the solar heat energy usage and decrease the heat pump working time. The long-term storage tank capacity of 15 m3 can increase the direct heating from solar by 41%. The direct heating system efficiency is 51%.


Author(s):  
Adnan Alashkar ◽  
Mohamed Gadalla

In this present paper, a performance analysis of an Integrated Solar Rankine Cycle (ISRC) is provided. The ISRC consists of a nanofluid-based Parabolic Trough Solar Collector (PTSC), and a Thermal Energy Storage System (TES) integrated with a Rankine Cycle. The effect of dispersing Copper (Cu) nanoparticles in a conventional heating fluid (Syltherm 800) on the output performance and cost of the ISRC is studied for different volume fractions, and for two modes of operation. The first mode assumes no storage, while the second assumes a storage system with a storage period of 7 hours. For the second mode of operation, the charging and discharging cycles are explained. The results show that the presence of the nanoparticles causes an increase in the overall energy produced by the ISRC for both modes of operation, and also causes a decrease in the Levelized Cost of Electricity (LEC), and an increase in the net savings of the ISRC. When comparing the two modes of operation it is established that the existence of a storage system leads to a higher power generation, and a lower LEC; however the efficiency of the cycle drops. It is seen that the maximum increase in the annual energy output of the ISRC caused by the addition of the nanoparticles is around 3.5%, while the maximum increase in the net savings is around 12.8%.


2013 ◽  
Vol 671-674 ◽  
pp. 2515-2519
Author(s):  
Xue Mei Wang ◽  
Zhen Hai Wang ◽  
Xing Long Wu

This project aims to study the optimal control model of the ice-storage system which is theoretically close to the optimal control and also applicable to actual engineering. Using Energy Plus, the energy consumption simulation software, and the simple solution method of optimal control, researchers can analyze and compare the annual operation costs of the ice-storage air-conditioning system of a project in Beijing under different control strategies. Researchers obtained the power rates of the air-conditioning system in the office building under the conditions of chiller-priority and optimal contro1 throughout the cooling season. Through analysis and comparison, they find that after the implementation of optimal control, the annually saved power bills mainly result from non-design conditions, especially in the transitional seasons.


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