Thermodynamic and Environmental Analysis of a High-temperature Heat Pump using HCFO-1224yd(Z) and HCFO-1233zd(E)

This paper investigates the use of two low global warming potential working fluids, HCFO-1224yd(Z) and HCFO-1233zd(E), in high-temperature heat pump systems. A simulation was performed at evaporating temperatures ranging from 50–70°C and a condensing temperature of 110°C. A solar thermal collector was used to supply the energy needs on the evaporator side. Energy, exergy, and environmental analyses were performed to evaluate both environmentally friendly refrigerants and compare them to HFC-245fa. The coefficient of performance (COP) and total exergy destruction represented the performance of the system, while the total equivalent warming impact was used to evaluate the environmental effect of each refrigerant. At an evaporation temperature of 50°C, HCFO-1224yd(Z) and HCFO-1233zd(E) showed comparable performance to R245fa, with COP values of about 2.74 and 2.69, respectively (R245fa had a COP value of about 2.66). The same results were also obtained at evaporation temperatures of 60°C and 70°C, at which R1224yd showed good performance compared to R1233zd and R245fa with COP values of 3.6 for 50oC evaporation temperature and 4.75 for 70oC evaporation temperature. Additionally, both suggested refrigerants had low direct emission compared to R245fa based on the results from the environmental analysis

Solar Air-Conditioning System at the University of Indonesia

Indonesia’s economic growth has continued at a steady rate of approximately 5% to 6% annually, and energy consumption in the entire country has been increasing year by year. Demand for air conditioning in buildings is expanding. In line with this expansion, a 239 kW solar air-conditioning system using a single-double effect combined absorption chiller was installed in a building at the University of Indonesia’s Faculty of Engineering located in Depok city, near Jakarta, with the aim of reducing greenhouse gas emissions. We collected and analyzed data from this air-conditioning system to better comprehend its performance. We report the outline and the performance of the chiller and the air-conditioning system

Solar absorption chiller performance prediction based on the selection of principal component analysis

In this paper, a method to predict the performance of an absorption chiller using solar thermal collectors as the energy input is analyzed rigorously. Artificial Neural Network (ANN) is developed based on experimental data to predict the performance of the solar absorption chiller system at Universitas Indonesia. In order to perform ANN accurately, some parameters such as chilled water inlet and outlet temperatures, cooling water inlet and outlet temperatures, solar hot water inlet and outlet temperatures, hot water inlet and outlet temperatures, ambient temperature and fuel consumption flow rate are chosen as the input variables. In addition, a Principle Component Analysis (PCA) is used to reduce the number of input variables for performance prediction. Without sacrificing the ANN's prediction accuracy, PCA identified the sensitive variables from all input variables. The developed ANN model combined with PCA (ANN + PCA) shows good performance which has a comparable error with ANN model, specifically the configuration 9–6-2 (9 neurons, 6 inputs, 2 outputs) of the ANN + PCA model leads to a COP root-mean-square error of 0.0145. Keywords: Absorption chiller, Neural network, Principal component analysis, Performance prediction, Solar energ

Air flow distribution and cooling performance on modular cold storage for fishery commodity

Cold storage plays a vital role in the supply chain of fishery products. Efficient cold storage design is a future challenge for developing regions with limited energy supplies. This paper aims to analyze the cooling performance and airflow distribution of modular cold storage. Modular cold storage is designed with a size of 20 ft for remote areas with the main cargo of fishery products. The analysis used empirical equations and numerical simulations of fluid flow and heat transfer. Variation of cooling load and inlet air velocity was conducted to investigate the cargo’s cooling distribution and cooling speed. To achieve the desired product temperature inside cold storage rooms have obtained different cooling times. The optimum cooling time in the anteroom is 5 h and in air-blast freezer room is 3.5 h with an inlet air velocity setting is 8 m/s both, while the optimum cooling time in the freezer room is 6 h with an inlet air velocity setting is 2 m/s. Furthermore, the results of this paper also offer recommendations for pre-cooling fish products to minimize excessive cooling in air-blast freezer room