scholarly journals Fabrication and Performance Evaluation of Cold Thermal Energy Storage Tanks Operating in Water Chiller Air Conditioning System

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4159
Author(s):  
Xuan Vien Nguyen
Keyword(s):  
Heat Transfer ◽  
Cold Storage ◽  
Storage Tank ◽  
Air Conditioning ◽  
Thermal Storage ◽  
Hot Water ◽  
Operating Costs ◽  
Heat Transfer Fluid ◽  
Storage Tanks ◽  
Air Conditioning System

In this study, cold and thermal storage systems were designed and manufactured to operate in combination with the water chiller air-conditioning system of 105.5 kW capacity, with the aim of reducing operating costs and maximizing energy efficiency. The cold storage tank used a mixture of water and 10 wt.% glycerin as a phase-change material (PCM), while water was used as heat transfer fluid (HTF). The cold storage heat exchanger was made of polyvinyl chloride (PVC). On the other hand, the thermal storage tank used water as the storage fluid with a capacity of 50 L of hot water per hour. The thermal storage did not use a pump for water transfer through the heat exchanger, so as to save energy and operating costs. In this paper, the operating parameters of the cold and thermal storage tanks are shown according to the results of experimental research, including the temperatures of cooling and heating load, heat transfer fluid, and cold storage material during the discharge process, as well as the discharge duration. The system assisted the air conditioner in cooling the internship workshop space at the university with an area of 400 m2, contributing to a remarkable reduction in air-conditioning system operating costs during the daytime. Furthermore, the system recovered waste heat from the compressor of the water chiller, and a thermal storage system was successfully built and operated, providing 50 L of hot water at a temperature of 60 °C per hour to serve the everyday needs of school students. This design was suitable for the joint operation of cold and thermal storage tanks and the water chiller air-conditioning system for cooling and heating applications.

Experimental Investigation of Thermal Storage Processes in a Thermocline Storage Tank

2011 ◽  
Author(s):  
Wafaa Karaki ◽  
Peiwen Li ◽  
Jon Van Lew ◽  
M. M. Valmiki ◽  
Cholik Chan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Storage Tank ◽  
Power Plants ◽  
Thermal Power ◽  
Energy Charge ◽  
Thermal Storage ◽  
Packed Bed ◽  
Heat Transfer Fluid ◽  
Energy Storage Efficiency

This paper presents an experimental study and analysis of the heat transfer of energy charge and discharge in a packed-bed thermocline thermal storage tank for application in concentrated solar thermal power plants. Because the energy storage efficiency is a function of many parameters including fluid and solid properties, tank dimensions, packing dimensions, and time lengths of charge and discharge, this paper aims to provide experimental data and a proper approach of data reduction and presentation. To accomplish this goal, dimensionless governing equations of energy conservation in the heat transfer fluid and solid packed-bed material are derived. The obtained experimental data will provide a basis for validation of mathematical models in the future.

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 Numerical Analysis of a Thermal Storage Tank as Part of a 20 kW Solar/gas Adsorption Air Conditioning System

2014 ◽  
Vol 57 ◽  
pp. 2600-2608 ◽  
Author(s):  
Cristian Adolfo ◽  
Gilberto A.A. Moreira ◽  
Belkacem Zeghmati ◽  
Antonio P.F. Leite
Keyword(s):  
Numerical Analysis ◽  
Storage Tank ◽  
Air Conditioning ◽  
Gas Adsorption ◽  
Thermal Storage ◽  
Air Conditioning System

Simulation of an Air-Cooled Solar-Assisted Absorption Air Conditioning System

2001 ◽  
Author(s):  
L. H. Alva Solari ◽  
J. E. González
Keyword(s):  
Storage Tank ◽  
Air Conditioning ◽  
Lithium Bromide ◽  
Thermal Storage ◽  
Ambient Air ◽  
Absorption System ◽  
Air Conditioning System ◽  
Component Design ◽  
Dynamic Cooling ◽  
Cooling Loads

Abstract This paper investigates the technical feasibility of using a compact, air-cooled, solar-assisted, absorption air conditioning system in Puerto Rico and similar regions. Computer simulations were conducted to evaluate the system’s performance when subjected to dynamic cooling loads. Within the computer model, heat and mass balances are conducted on each component of the system, including the solar collectors, thermal storage tank, the air-cooled condenser, and the air-cooled absorber. Guidance on component design and insight into the effects of such operating factors as ambient air temperature were gained from exercising the simulation model. Comparisons are made with an absorption air conditioning system that uses a cooling tower instead of air-cooled components. The particular absorption system of study is one that uses lithium bromide and water as the absorbent and refrigerant, respectively. The heat input to the absorption system generator is provided by an array of flat plate collectors that are coupled to a thermal storage tank. Systems having nominal cooling capacities of 10.5, 14, and 17.5 kW were considered. Useful information about the number of collectors needed, storage tank volume and efficiency of the overall system is presented.

Performance of Chiller in a Solar Absorption Air Conditioning System With Partitioned Hot Water Storage Tank

2000 ◽  
Vol 123 (1) ◽  
pp. 48-50 ◽  
Author(s):  
Z. F. Li ◽  
K. Sumathy
Keyword(s):  
Storage Tank ◽  
Air Conditioning ◽  
Lithium Bromide ◽  
Hot Water ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Water Storage Tank ◽  
Solar Cooling ◽  
Solar Powered ◽  
System Designs

This paper reports the performance of a lithium bromide absorption chiller in a solar powered air conditioning system, when being operated conventionally. The chiller performance based on a modified solar powered absorption air conditioning system which is integrated with a partitioned storage tank has been presented and discussed. It is shown that, by partitioning the storage tank, the chiller performance is not significantly affected, and the solar powered cooling effect can be realized much earlier, achieving a higher total solar cooling COPsystem, compared to the conventional system designs.

Transient Hydrodynamic Phenomena and Conjugate Heat Transfer During Cooling of Water in an Underground Thermal Storage Tank

2004 ◽  
Vol 126 (1) ◽  
pp. 84-96 ◽  
Author(s):  
E. Papanicolaou ◽  
V. Belessiotis
Keyword(s):  
Heat Transfer ◽  
Storage Tank ◽  
Conjugate Heat Transfer ◽  
Transient Flow ◽  
Thermal Storage ◽  
Hot Water ◽  
Uniform Temperature ◽  
Thermal Fields ◽  
Flow And Heat Transfer ◽  
Insight Into

The flow and heat transfer phenomena inside an underground thermal storage tank, initially filled with hot water at an almost uniform temperature and then left to interact with the cold surroundings, are studied numerically. The purpose of the study is to gain insight into how these phenomena affect the heat losses to the surroundings, before a new charging process takes place. A two-dimensional numerical model to solve for the transient flow and thermal fields within the tank coupled with the heat transport through the tank walls and within the ground are employed. Natural convection is found to dominate at the early transients when a strong recirculation develops, with a Rayleigh number characteristic of turbulent flow. A low-Re k−ε turbulence model is used for the computation. As time proceeds and the temperature differences between water and surroundings decrease, the recirculation decays and the heat transfer is dominated by thermal diffusion. The ground properties are varied, mainly in order to account for different moisture contents in the ground. Comparisons are made under realistic conditions with preliminary experimental results showing satisfactory agreement.

Optimal operation of heat source and air conditioning system with thermal storage tank using nonlinear programming

Energy ◽  
2021 ◽  
Vol 222 ◽  
pp. 119936
Author(s):  
Hitoi Ono ◽  
Yuichi Ohtani ◽  
Minoru Matsuo ◽  
Toru Yamaguchi ◽  
Ryohei Yokoyama
Keyword(s):  
Nonlinear Programming ◽  
Heat Source ◽  
Storage Tank ◽  
Air Conditioning ◽  
Thermal Storage ◽  
Optimal Operation ◽  
Air Conditioning System
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