Simulation and Dynamic Characteristics of Discharging Process of Storage Tank Used in Conventional Air-Conditioning

2011 ◽  
Vol 383-390 ◽  
pp. 2974-2977
Author(s):  
Xiao Yan Li ◽  
Yan Yan Wu ◽  
Zhi Fen Cen
Keyword(s):  
Thermal Energy ◽  
Storage Tank ◽  
Dynamic Performance ◽  
Melting Process ◽  
Melting Rate ◽  
Heat Transfer Process ◽  
Inlet Temperature ◽  
Appreciable Change ◽  
Apparent Heat Capacity ◽  
Capacity Method

Mathematical model of heat transfer process of a latent heat thermal storage tank was established, dynamic performance and melting process of cool storage tank were simulated by the apparent heat capacity method. the relation of melting rate along with time and cold thermal energy released along with time were obtained. The results show that no appreciable change in the total cold thermal energy released is observed for the increase of flow rate, whereas improvement on total cold thermal energy released due to the increase of inlet temperature is detectable. At the cool discharge condition, the best inlet temperature of storage tank is at 12°C-13°C.

Dynamic Character Study on Cool Thermal Energy Storage Process of Storage Tank for Air-Conditioning System

2012 ◽  
Vol 433-440 ◽  
pp. 1052-1056
Author(s):  
Xiao Yan Li ◽  
Yan Yan Wu ◽  
Zhi Fen Cen
Keyword(s):  
Energy Storage ◽  
Flow Rate ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Tank ◽  
Air Conditioning ◽  
Heat Transfer Fluid ◽  
Inlet Temperature ◽  
Air Conditioning System ◽  
Appreciable Change

Mathematical model of the storage tank for air-conditioning condition was established, the dynamics character of a new type of PCM in the storage tank was studied., and the model was numerical simulated by the method of heat capacity. Effects of flow rate and inlet temperature of heat transfer fluid (HTF) on charging process of the storage tank were obtained. The results show that no appreciable change in the total cold thermal energy storage is observed for the increase of flow rate, whereas the improvement of the total cold thermal energy storage due to the decrease of inlet temperature is detectable, when cold storage is finished during low peak of electricity, the best inlet temperature of storage tank is at 2°C-3°C.

scholarly journals Evaluation and Improvement of PCM Melting in Double Tube Heat Exchangers Using Different Combinations of Nanoparticles and PCM (The Case of Renewable Energy Systems)

2021 ◽  
Vol 13 (19) ◽  
pp. 10675
Author(s):  
Ali Motevali ◽  
Mohammadreza Hasandust Rostami ◽  
Gholamhassan Najafi ◽  
Wei-Mon Yan
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Exchangers ◽  
Storage System ◽  
Melting Process ◽  
Energy Storage System ◽  
Melting Rate ◽  
Thermal Energy Storage System ◽  
Dispersion Of Nanoparticles

In this work, the melting process of phase change material (PCM) in double tube heat exchangers was investigated and evaluated through the use of different combinations (1, 2, 3% Nano-Enhanced PCM and 1, 3, 5% Nano-HTF) of GQD, as well as SWCNT nanoparticles and PCM (RT82). In this study, the effect of three different methods, namely the dispersion of nanoparticles in PCM (nano-enhanced PCM), the dispersion of nanoparticles in HTF (nano-HTF), and the simultaneous dispersion of nanoparticles in PCM and HTF (nano-enhanced PCM, nano-HTF) concerning the nanoparticles participation in the thermal energy storage system in a double tube heat exchanger was evaluated. Other effective factors, such as the inlet fluid temperature, different Reynolds numbers, fin as well as new parameter of pipe, and fin thickness were also evaluated. The results showed that the highest effect of different parameters on the PCM melting process was related to the 1% nano-HTF and 3% nano-enhanced PCM nanoparticles of SWCNT, which decreased the PCM melting rate by about 39%. The evaluation of the effect of pipe and fan thickness also showed that the melting rate improved by 31% through reducing the thickness of the HTF fin and pipe. In general, the current study followed two purposes first, to examine three methods of the dispersion of nanoparticles in the thermal energy storage system; second, to reduce the thickness of the tube and fin. Findings of the study yielded positive results.

Close-Contact Melting Inside an Elliptical Cylinder

2000 ◽  
Vol 122 (4) ◽  
pp. 192-195 ◽  
Author(s):  
Sergei A. Fomin ◽  
Alexander V. Wilchinsky ◽  
Takeo S. Saitoh
Keyword(s):  
Mathematical Model ◽  
Thermal Energy ◽  
Close Contact ◽  
Energy Systems ◽  
Elliptic Cylinder ◽  
Melting Process ◽  
Melting Rate ◽  
Contact Melting ◽  
Approximate Mathematical Model ◽  
Characteristic Scales

An approximate mathematical model of contact melting in a horizontal elliptic cylinder is developed. The main characteristic scales and nondimensional parameters that describe the principal features of the melting process are found. It is shown that melting rate depends on the shape of the capsule. This is especially important for the design of practical latent heat thermal energy systems. [S0199-6231(00)00504-9]

Solving the Problem of Silicon Dioxide Melting Based on Deviation Model

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Yuhan Sun
Keyword(s):  
Silicon Dioxide ◽  
Blast Furnace Slag ◽  
Melting Process ◽  
Melting Rate ◽  
Dissolution Behavior ◽  
Characteristic Parameters ◽  
Contour Feature ◽  
Time Periods ◽  
Main Component ◽  
Furnace Slag

Abstract: In order to reveal the dissolution behavior of iron tailings in blast furnace slag, we studied the main component of silica in iron tailings. First, edge contour features need to be established to represent the melting process of silica. We choose shape, perimeter, area and generalized radius as objects. By independently analyzing the influence of these four indexes on the melting rate, the area and shape were selected as the characteristic parameters of the edge contour of the silica particles. Then, the actual melting rate of the silica is estimated by the edge contour feature index. Finally, we can calculate the melting rate of the first second of three time periods of 0.00010312mm3/s，0.0002399mm3/s，0.0000538mm3/s.

scholarly journals Minimum Number of Experimental Data for the Thermal Characterization of a Hot Water Storage Tank

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4741
Author(s):  
María Gasque ◽  
Federico Ibáñez ◽  
Pablo González-Altozano
Keyword(s):  
Experimental Data ◽  
Water Temperature ◽  
Temperature Profile ◽  
Storage Tank ◽  
Water Storage ◽  
Hot Water ◽  
Experimental Temperature ◽  
Inlet Temperature ◽  
Water Storage Tank ◽  
Minimum Number

This paper demonstrates that it is possible to characterize the water temperature profile and its temporal trend in a hot water storage tank during the thermal charge process, using a minimum number of thermocouples (TC), with minor differences compared to experimental data. Four experimental tests (two types of inlet and two water flow rates) were conducted in a 950 L capacity tank. For each experimental test (with 12 TC), four models were developed using a decreasing number of TC (7, 4, 3 and 2, respectively). The results of the estimation of water temperature obtained with each of the four models were compared with those of a fifth model performed with 12 TC. All models were tested for constant inlet temperature. Very acceptable results were achieved (RMSE between 0.2065 °C and 0.8706 °C in models with 3 TC). The models were also useful to estimate the water temperature profile and the evolution of thermocline thickness even with only 3 TC (RMSE between 0.00247 °C and 0.00292 °C). A comparison with a CFD model was carried out to complete the study with very small differences between both approaches when applied to the estimation of the instantaneous temperature profile. The proposed methodology has proven to be very effective in estimating several of the temperature-based indices commonly employed to evaluate thermal stratification in water storage tanks, with only two or three experimental temperature data measurements. It can also be used as a complementary tool to other techniques such as the validation of numerical simulations or in cases where only a few experimental temperature values are available.

Investigation on the melting process of phase change material in a square cavity with a single fin attached at the center of the heated wall

2018 ◽  
Vol 83 (1) ◽  
pp. 10902 ◽  
Author(s):  
Müslüm Arıcı ◽  
Ensar Tütüncü ◽  
Hasan Karabay ◽  
Antonio Campo
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Melting Process ◽  
Melting Rate ◽  
Paraffin Wax ◽  
Heated Wall ◽  
Dual Function ◽  
Square Cavity ◽  
Change Material ◽  
Fin Length

In this study, melting of a phase change material (PCM) in a square cavity with a single fin attached at the center of the heated wall is studied numerically employing the enthalpy-porosity method. The opposite wall to the heated wall in the square cavity is cold. The other two adjacent walls are thermally insulated. Paraffin wax is chosen as a PCM due to its demonstrable favorable properties. The thermophysical properties of the paraffin wax are assumed to be a dual function of temperature and phase. The influence of the fin length on the melting process of the paraffin wax is examined. Moreover, the orientation of the square cavity on the melting process is scrutinized. The numerical results elucidate that the melting rates increase significantly by embedding the fin into the paraffin wax. As the fin length is incremented, the melting rate intensifies considerably during the early stages of melting. However, the effect of the fin length on the melting rate diminishes after a long period of heating has happened. It is also observed that the melting rate can be augmented significantly by changing the orientation of the heated wall in the square cavity.

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