According to the design scenario of the DHRS, the heat exchange power loaded on the surface of heat exchange tubes is 0.1 MW and the inlet temperature of the diathermic oil is 225[degrees]C.
where [DELTA][rho] is the diathermic oil density difference between the inlet and outlet of the auxiliary heat exchanger and [DELTA]h refers to the natural circulation height.
However, the heat transfer efficiency is greatly affected by the velocity of the diathermic oil.
Due to the long length of the heat exchange tubes, it is concluded that the diathermic oil is sufficiently heated while flowing through the tube and flowing out of the heat exchanger at a design temperature and enters the connected pipes.
The diathermic oil at the heat exchange tubes is gradually heated by the heat transferred from the interface, and the temperature rises from 186.94[degrees]C to 217.22[degrees]C.