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This article analyses the possibility of using hydrogen as fuel in furnaces used in the metallurgical industry. The research was conducted for a selected continuous furnace. For this purpose, based on actual measurements, a heat balance of the furnace was prepared to determine its energy indicators. These values were used to verify the developed numerical model in IPSEpro 7.0 software. Numerical calculations were performed for three variants: pure natural gas; 30% hydrogen, 70% natural gas; and 100% hydrogen. The determined values of gas and combustion air streams allowed for achieving the assumed charge temperature in the heating technology. Calculations of the impact of the excess combustion air ratio on process parameters were also carried out. It was found that no changes are required in the exhaust gas removal system, but verification of the fan supplying air to cool the exhaust gases before the recuperator is necessary. The amount of hydrogen required to fuel the continuous furnace also increases significantly (nearly threefold), which may also affect operating costs. At the same time, the emission of carbon dioxide into the atmosphere is completely reduced, which may be an important criterion when considering modernization options for heating furnaces in the metallurgical industry. [ABSTRACT FROM AUTHOR]

Broadly defined climate protection is a powerful incentive in the search for environmentally friendly refrigeration technologies. Adsorption chillers are considered to be one such technology; however, their main disadvantages include a low cooling capacity, a low energy efficiency ratio (EER), and cyclic operation. Thus, a great deal of effort is being put into improving adsorption-chiller performance. In this paper, the influence of the spray angle, the number of nozzles, and the water flow rate through the nozzles on adsorption-chiller performance was investigated. Adsorption-chiller performance was investigated mainly in terms of the cooling capacity (CC), the energy efficiency ratio (EER), and the specific cooling power (SCP). The results indicated that the chiller's cooling capacity increased from about 210 W to 316 W and that the EER increased from 0.110 to 0.167 when the spray angle of the nozzles was increased from 90° to 120°. It was also reported that increasing the flow rate of water through the nozzles did not improve the average cooling capacity or the other performance parameters but resulted in more stable operation of the chiller. Additionally, using six nozzles instead of three improved the average cooling capacity and EER tenfold. [ABSTRACT FROM AUTHOR]