18 May 2017

P.3.3.2 Development of steam generation heat pump through refrigerant replacement approach

In this study, design of high temperature heat pump to produce low pressure steam for industrial processes was conducted. For efficiency and reliability refrigerant of high temperature heat pump should have critical point above steam generation condition. Among commercial refrigerant satisfying this, R245fa was selected. For the generation of low pressure steam, pressure reduction method was applied. R245fa and pressure reduction methods made the high temperature heat pump cycle similar to that of hot water of R134a. Therefore refrigerant change approach from R134a to R245fa was selected for the preliminary research. Under same suction superheat R245fa tends to have smaller discharge superheat than R134a. To secure superheat without increasing temperature difference in evaporator, internal heat exchanger was applied to R245fa heat pump cycle. Sensitivity analysis to suction superheat was performed for R245fa and R134a. The results showed that R245fa has better performance than R134a. This means R245fa has more advantages in applying internal heat exchanger compared to R134a.