Chang-Dae Park

Thermal energy is essential for various industrial processes like liquid heating, drying, and sterilization, demanding temperatures above 100°C. It is mainly generated from fossil fuels, which often leads to carbon dioxide (CO 2) emissions and climate crises. Therefore, it is imperative to shift from fossil-fuel based energy to renewable or cleaner energy for the sake of the environment. High-temperature heat pumps are key components for shifts in industrial fields. Industrial high-temperature heat pumps require high-temperature heat sources for evaporation. A solar thermal system can provide a high-temperature heat source and direct heat production. This study aims to evaluate the economic feasibility of an integrated system that combines a solar thermal system and a high-temperature heat pump for supplying steam to industrial processes. Modeling and performance simulations were conducted on the system using Simulink. Economic factors such as the benefit-cost ratio, net present value, and levelized cost of heating (LCOH) were analyzed based on the solar collector area. The results of the study demonstrated that the solar thermal-heat pump can economically substitute a 0.5-ton steam boiler. Notably, CO 2 emissions can be reduced by up to 1,600 tons annually by replacing LPG boilers.

The thermal energy used in industrial processes is largely obtained from fossil fuels, causing global warming through carbon dioxide emissions. Worldwide efforts are underway to achieve decarbonization by using renewable energy sources to supply thermal energy. Solar energy, that offers infinite energy potential over a wide temperature range, and heat pumps, that provide a stable and an efficient heat supply, can synergize and capitalize on the advantages of each other. This study aimed to develop a solar thermal source heat pump (SSHP) to replace the existing 0.5 ton/h LPG steam boiler in food processing. Through a performance analysis, the heat supply ratio, solar fraction, and seasonal performance factor were derived based on the solar collector area and storage volume. The results indicated that the heat supply ratio of the SSHP was influenced more by the collector area than by the thermal storage volume. When the SSHP collector area was below a certain value, increasing the thermal storage volume reduced the SSHP heat supply ratio. Therefore, to operate the system stably and achieve a high performance index, the collector area must be larger. For the subject food process, a collector area larger than 210 m 2 was required to achieve a seasonal performance factor exceeding 2.52, equivalent to power generation efficiency.

The global trend of renewable energy generation and the advent of the Internet of Things technology has popularized inexpensive integrated monitoring technology. Accordingly, the Renewable Energy Monitoring System (REMS) project, which monitors solar plants subsidized by National funds, has been expanding its target since 2018. Concurrently, the mandatory post-management system became effective in 2020 to strengthen the post-management system. The 3-sigma rule is used to determine the control chart for the normal operation of solar systems from the monitoring data. In this study, solar plants with normal operation within the control chart were suggested to be excluded from field investigation with a focus on the management of solar plants with abnormal operation outside the control chart to improve the overall investigation into inefficiencies in the mandatory post-management system. Improvements to the monitoring system operation plan were also suggested.