scholarly journals Thermal Performance Study on a Sensible Cool Thermal Energy Storage System for Building Air-Conditioning Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Kesavan Muthaiyan ◽  
Chidambaram Lakshmanan ◽  
Kaiwalya Raj ◽  
Mangat Ram Sharma ◽  
Rajamani Narayanasamy ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Heat Exchange ◽  
Air Conditioning ◽  
Heat Storage ◽  
Cooling System ◽  
Storage System ◽  
Inlet Temperature ◽  
Sensible Heat ◽  
Building Sector ◽  
Building Cooling

In most developed and developing nations, nearly 40% of the energy generated is utilized in the building sector, in which nearly 50% of the energy is consumed by building cooling/heating systems. However, the energy requirement for building cooling/heating varies continuously with respect to time. Hence, in hot countries, if the cooling system is integrated with a storage system, the cooling system need not be designed for the peak load requirement. Further, this kind of storage system is very useful and economically beneficial in the scenario of dynamic electricity tariff, being introduced in many countries in the emerging renewable energy scenario to solve the grid stability issues. Further, it is very useful to promote microgrid with distributed renewable power generation. Considering the above, the major objective of the present research is to demonstrate the integration of the air-conditioning system with a sensible heat storage unit for residential applications. An experimental setup is constructed, and experiments were conducted to evaluate the heat exchange behavior during the charging and discharging process by varying the inlet temperature and the mass flow rate of the heat exchange fluid through the circuit. It is observed that the set temperature of the cool storage tank is to be maintained above +5°C to achieve better efficiency during the charging process. During the discharging process, the room could be maintained at the required comfort condition for a duration of 285 min with 29 cycles of operations between the set point temperature limits of 25°C to 28°C. When the inlet brine temperature of the cooling unit reached 20°C, in the next cycle, bringing down the room temperature again to 25°C could not be achieved. The results shown in this work are beneficial for efficiently operating the cooling system and useful in promoting renewable energy in the near future in the building sector. Also, the low-temperature sensible heat storage system is capable of maintaining the storage temperature at approximately +4°C, instead of -4°C normally employed in the case of latent heat-based storage system that allows higher performance in the sensible heat storage system.

scholarly journals POTENTIAL USE OF PHASE CHANGE MATERIALS IN GREENHOUSES HEATING: COMPARISON WITH A TRADITIONAL SYSTEM

2009 ◽  
Vol 40 (3) ◽  
pp. 25
Author(s):  
Claudio Caprara ◽  
Giovanni Stoppiello
Keyword(s):  
Heat Exchange ◽  
Low Temperature ◽  
Phase Change ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Storage System ◽  
Inlet Temperature ◽  
Water Tank ◽  
Sensible Heat ◽  
Solar Collectors

In order to use solar radiation as thermal energy source, heat storage equipments result necessary in each application where continuous supply is required, because of the natural unsteady intensity of radiation during the day. Thermal solar collectors are especially suitable for low temperature applications, since their efficiency decreases when an high inlet temperature of fluid flowing through them is established. On the other hand, low temperatures and low temperature gaps, above all, make very difficult to use traditional sensible heat storing units (water tanks), because of the very large amounts of material required. In this work, a traditional sensible heat storage system is compared with a latent heat storing unit based on phase change materials (PCMs). As a case study, a 840 m3 greenhouse heating application was considered with an inside constant temperature of 18°C. It is thought to be heated by using single layer plate thermal solar collectors as energy source. Inlet temperature of the collectors fluid (HTF) was fixed at 35°C (little higher than melting temperature of PCMs) and a constant flux of 12 l/m2 hour was established as technical usual value. At these conditions, 215m2 solar panels exposed surface resulted necessary. The sensible heat storage system considered here is a traditional water tank storing unit equipped with two pipe coils, respectively for heat exchanges with HTF from collectors and water flux for greenhouse heating. Available DT for heat exchange is estimated as the difference of minimum HTF temperature (in outlet from the collectors) and the required water temperature for greenhouse heating. The latent heat storing unit is instead a series of copper rectangular plate shells which a phase change material is filled in (Na2SO4⋅10H2O). Heat transfer fluids flow through thin channels between adjacent plates, so that a large heat exchange available surface is achieved. The developed computational model (Labview software) permits to superimpose heat exchanges daily curves between heat storing materials and heat transport fluids (for both of the fluids and the heat storing equipments) on the energy supply/demand ones, respectively calculated on the basis of greenhouse energy demand and solar collectors dimensions, characteristics and efficiency. In this manner, units design is achieved by changing thermal energy storing units dimensions, in order that the corresponding heat exchange curves coincide with the previously calculated ones. Successively, among all the possible configurations, the ones showing lower units volumes and less amount of storing materials are chosen as the optimal design solutions. It has been proven that PCMs materials are much more suitable for low temperature applications than sensible heat storing materials (water). In the case of water tank, an about 15.8m3 total volume is required while for PCMs equipment the total volume of storing unit is reduced to about 2.2 m3, such as about seven times total volume less. Besides, according to the simplified and steady state model calculations, PCMs unit shows a better response to the hourly energy fluctuations of solar collectors and greenhouse demand than water tank unit. This is especially due to the high available exchange surface achieved in proposed arrangement.

Solid Media Thermal Storage Development and Analysis of Modular Storage Operation Concepts for Parabolic Trough Power Plants

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Doerte Laing ◽  
Wolf-Dieter Steinmann ◽  
Michael Fiß ◽  
Rainer Tamme ◽  
Thomas Brand ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Power Plants ◽  
Heat Storage ◽  
Storage Systems ◽  
Storage System ◽  
Sensible Heat ◽  
Economic Optimization ◽  
Parabolic Trough ◽  
Solid Media ◽  
Exergetic Analysis

Cost-effective integrated storage systems are important components for the accelerated market penetration of solarthermal power plants. Besides extended utilization of the power block, the main benefits of storage systems are improved efficiency of components, and facilitated integration into the electrical grids. For parabolic trough power plants using synthetic oil as the heat transfer medium, the application of solid media sensible heat storage is an attractive option in terms of investment and maintenance costs. For commercial oil trough technology, a solid media sensible heat storage system was developed and tested. One focus of the project was the cost reduction of the heat exchanger; the second focus lies in the energetic and exergetic analysis of modular storage operation concepts, including a cost assessment of these concepts. The results show that technically there are various interesting ways to improve storage performance. However, these efforts do not improve the economical aspect. Therefore, the tube register with straight parallel tubes without additional structures to enhance heat transfer has been identified as the best option concerning manufacturing aspects and investment costs. The results of the energetic and exergetic analysis of modular storage integration and operation concepts show a significant potential for economic optimization. An increase of more than 100% in storage capacity or a reduction of more than a factor of 2 in storage size and therefore investment cost for the storage system was calculated. A complete economical analysis, including the additional costs for this concept on the solar field piping and control, still has to be performed.

Analysis on unsteady heat transfer and fluid flow through sensible heat storage system

2021 ◽  
Author(s):  
Sasikumar C ◽  
Sundaresan R ◽  
Rajaganapthy C ◽  
Nagaraj M ◽  
Radha Krishnan Beemaraj
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Storage ◽  
Storage System ◽  
Sensible Heat ◽  
Unsteady Heat Transfer ◽  
Flow Through

scholarly journals Numerical Modeling of the Melting Process in a Shell and Coil Tube Ice Storage System for Air-Conditioning Application

2019 ◽  
Vol 9 (13) ◽  
pp. 2726 ◽  
Author(s):  
Seyed Soheil Mousavi Ajarostaghi ◽  
Sébastien Poncet ◽  
Kurosh Sedighi ◽  
Mojtaba Aghajani Delavar
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Energy Storage ◽  
Cold Storage ◽  
Air Conditioning ◽  
Storage System ◽  
Melting Process ◽  
Melting Time ◽  
Inlet Temperature ◽  
Geometrical Parameters

Cold thermal energy storage, as a promising way of peak-shifting, can store energy by using cheap electricity during off-peak hours and regenerate electricity during peak times to reduce energy consumption. The most common form of cold storage air conditioning technology is ice on the coil energy storage system. Most of the previous studies so far about ice on coil cold storage system have been done experimentally. Numerical modeling appears as a valuable tool to first better understand the melting process then to improve the thermal performance of such systems by efficient design. Hence, this study aims to simulate the melting process of phase change materials in an internal melt ice-on-coil thermal storage system equipped with a coil tube. A three-dimensional numerical model is developed using ANSYS Fluent 18.2.0 to evaluate the dynamic characteristics of the melting process. The effects of operating parameters such as the inlet temperature and flowrate of the heat transfer fluid are investigated. Also, the effects of the coil geometrical parameters—including coil pitch, diameter, and height—are also considered. Results indicate that conduction is the dominant heat transfer mechanism at the initial stage of the melting process. Increasing either the inlet temperature or the flowrate shortens the melting time. It is also shown that the coil diameter shows the most pronounced effect on the melting rate compared to the other investigated geometrical parameters.

On Thermoeconomics of a Sensible Heat, Thermal Energy Storage System

1995 ◽  
Vol 117 (3) ◽  
pp. 255-259 ◽  
Author(s):  
M. A. Badar ◽  
S. M. Zubair
Keyword(s):  
Heat Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Optimum Number ◽  
Sensible Heat ◽  
Hot Gas ◽  
Gas Source ◽  
Charging Time ◽  
Thermal Energy Storage System ◽  
Form Model

A closed-form model for the second-law-based thermoeconomic optimization of a sensible heat storage system, in which the energy is stored in a large liquid bath from a hot-gas source, is discussed with an example problem. The results are compared with those obtained from Bejan’s analysis to illustrate usefulness of the present approach. The influence of important parameters on the optimum number of heat transfer units Ntu,opt, and dimensionless charging time θopt, are presented in a graphic form.

scholarly journals Study of High-Temperature Sensible Heat Storage System. 2nd Report. Experimental Results and Effectiveness of Storage.

1991 ◽  
Vol 57 (541) ◽  
pp. 3232-3236
Author(s):  
Makio IWABUCHI ◽  
Tokuji MATSUO ◽  
Masahisa FUJIMOTO ◽  
Yoshio SHIMADA ◽  
Katsuhiko NARITA ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Storage ◽  
Storage System ◽  
Experimental Results ◽  
Sensible Heat

scholarly journals Radiation of Heat in an Insulating Vacuum Layer

2017 ◽  
Vol 69 (1) ◽  
pp. 87-100
Author(s):  
Mária Minárová
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Exchange ◽  
Heat Storage ◽  
Storage System ◽  
Heat Accumulation ◽  
Insulating Layer ◽  
System A ◽  
Set Up ◽  
Heat Transfer By Radiation

Abstract The paper is motivated by the previous research concerning the heat transfer in a heat accumulation device. The device had been explored, built up and tested with the aim of utilization of cheap solar energy and its storage. In this heat storage system, a vacuum-like gap between two concentric containers acts as an insulating layer, radiation being the predominant heat transfer type in the gap. The better knowledge and understanding of the heat exchange by radiation, the more effectiveness of the insulation of the layer can be reached. Heat transfer by radiation is explored in the paper, mathematical model is set up, the algorithm of non-linear transient computation is introduced, and some illustrative results of this computation are performed.

Advanced Thermal Energy Storage Technology for Parabolic Trough

Solar Energy ◽  
2003 ◽  
Author(s):  
Rainer Tamme ◽  
Doerte Laing ◽  
Wolf-Dieter Steinmann
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Heat Storage ◽  
Storage Systems ◽  
Storage System ◽  
Discharge Process ◽  
Sensible Heat ◽  
Parabolic Trough ◽  
Storage Unit ◽  
Solid Media

The availability of storage capacity plays an important role for the economic success of solar thermal power plants. For today’s parabolic trough power plants, sensible heat storage systems with operation temperatures between 300°C and 390°C can be used. A solid media sensible heat storage system is developed and will be tested in a parabolic trough test loop at PSA, Spain. A simulation tool for the analysis of the transient performance of solid media sensible heat storage systems has been implemented. The computed results show the influence of various parameters describing the storage system. While the effects of the storage material properties are limited, the selected geometry of the storage system is important. The evaluation of a storage system demands the analysis of the complete power plant and not only of the storage unit. Then the capacity of the system is defined by the electric work produced by the power plant, during a discharge process of the storage unit. The choice of the operation strategy for the storage system proves to be essential for the economic optimization.

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