Pre-Cooling Concrete System in Massive Concrete Production: Energy Analysis and Refrigerant Replacement

Abstract

Several techniques for cooling mass concrete structures were developed in order to increase structural integrity and reduce the influence of cement hydration, which sometimes causes cracking in concrete structures, negatively affecting their durability. This research focuses on cooling system design, initial investment, and the influence of different refrigerants on cooling system performance aims in producing higher quality massive concrete. Cooling aggregates in massive concrete structures such as desert dams can be performed by employing cooled air from an air conditioning duct system or chilled water. The experimental study illustrates the relationship between the coefficient of performance COP, the evaporator temperature, cooling capacity, and refrigerant mass flow rate as a function of the evaporator temperature, cooling capacity, and refrigerant mass flow rate. The findings of the experiments were utilized to verify a numerical model developed utilizing engineering equation solver (EES) software. The performance of the vapor compression of the cooling systems was compared using alternative refrigerants, including R22, R32, and R410a at different operating conditions. This study revealed that R22 refrigerant has a higher coefficient of performance than R32 and R410A, while R32 has the highest cooling capacity among other refrigerants.

Freeze and Thaw Effect on Asphalt Concrete Mixtures Modified with Natural Bentonite Clay

“…In general, the performance of asphalt mixtures determines road-pavement performance, especially when pavement is exposed to water through its porous medium; water in porous materials not only causes physical degradation but also carries aggressive agents such as carbon dioxide (CO 2 ), chloride, and sulfates, which can lead to chemical degradation and severely reduce the durability of AC mixtures [43,44]. In addition to that, the FT effect on AC is a significant parameter that contributes to road-pavement damage.…”

Multiple Thermal Parameter Inversion for Concrete Dams Using an Integrated Surrogate Model

“…During the construction of concrete dams, thermal cracks on concrete may occur due to unfavorable temporal and spatial temperature variations, affecting the integrity and durability of its structure [1][2][3]. To avoid such cracks, the main idea is to use FEM to track the actual temperature load of the dam dynamically, and then design reasonable temperature control and crack prevention schemes based on the crack resistance of the concrete [4][5][6].…”

Fuzzy and Matlab/Simulink Modelling of the Air Compression Refrigeration Cycle

“…Additionally, the working fluid for this refrigeration cycle is readily available at no cost, making it economically attractive. However, due to the low efficiencies of the compressor and expander [3] and [4], the coefficient of performance (COP) of this refrigeration cycle is relatively low.…”