Experimental study of boiling heat transfer characteristics of forced flow in annular tube under negative pressure

In order to investigate the recycling technology for efficiently recovering low-temperature wastewater waste heat from industrial production, we built an experimental device forced boiling transfer in annular tube. This paper takes a ring casing evaporator with inner tube diameter of 30 mm, length 1450 wall thickness 0.8 and outer 14.2 which was used as main object study. We conducted research on single-phase liquid flow two-phase phase change within tubes by varying inlet circulating hot water temperature (60–85 °C), mass rate (0.85, 1.27, 1.69 kg m−2 s−1), inclination angle (0°–90°). The results indicate that coefficient sleeves is significantly enhanced compared convective tubes. signifies employing pipe recovery can achieve highly efficient processes. study also reveals increase angle, surface follows trend initial followed decrease. Near 30° jacket tube, reaches its maximum value. findings this provide certain theoretical guidance application energy-saving field medium- utilization.