2.1.2. Low temperature section mode

2.1.2. Low temperature section model design of heat exchangerThe low-temperature section material of the heat exchanger isuse water-carbon steel, water-carbon steel heat pipe internal sat-urated steam temperature is higher with saturation vapor pres-sure. For security reasons, water-carbon steel heat pipe normalwork temperature is generally lower than 250°C. The designmodel of low temperature section and the conventional HPHEdesign model is exactly the same.2.1.3. Model design of the transition partThe HPHE in the moderate temperature section and low tem-perature section is determined according to the normal worksteam temperature of the tube with the normal work temperaturerange of naphthalene heat pipe is 250-400。C, and the normalwork temperature of water carbon steel tube does not exceed240°C, in the temperature range of 240-250 °C is formation of avacuum, the vacuum should be keep in transition section.Preliminary design can be considered by a single naphthalene heatpipe or a transition region of water- carbon steel heat pipe, byadjusting the structure parameters of the water-carbon steel heatpipe and naphthalene heat pipe will make low temperature and