Heat exchange device

A heat exchange device comprising:

• a heat exchanging unit that electrically operates to exchange heat with a fluid flowing through a path;
• a fluid pressure-feeding unit that electrically operates to pressure-feed the fluid to the path;
• a fluid temperature detecting unit to detect a temperature of the fluid passing through the heat exchanging unit;
• a current and voltage measuring unit to measure a current and a voltage that are input to the heat exchanging unit;
• and
• a control unit to control the heat exchanging unit and the fluid pressure-feeding unit based on the detected temperature, and the measured current and the measured voltage,
• wherein the control unit
• (I) calculates an internal temperature of the heat exchanging unit based on the measured current and the measured voltage,
• (II) calculates a surface temperature of the heat exchanging unit from the calculated internal temperature and an input power to the heat exchanging unit;
• (III) calculates a temperature difference between the calculated surface temperature and a target temperature of the fluid;
• (IV) calculates a target surface temperature of the heat exchanging unit from the calculated temperature difference and the detected temperature of the fluid, and
• (V) controls the input power to the heat exchanging unit or a flow rate of the fluid by the fluid pressure-feeding unit so that the calculated surface temperature becomes the target surface temperature.