Difference between positive displacement heat exchanger and semi positive displacement heat exchanger

The difference between the volumetric heat exchanger and the semi volumetric heat exchanger is that the semi volumetric heat exchanger tube bundle has a cylinder, while the volumetric heat exchanger does not.

The advantages of semi volumetric heat exchanger are

(1) High heat transfer coefficient

The elastic tube bundle is a high efficient heat transfer element made of red copper with high thermal conductivity. With a reasonable internal structure of the heat exchanger, the performance of the heat exchanger is greatly improved.

(2) It is not easy to scale because the heat exchange tubes are mostly made of red copper, and the fluid that is easy to form turbulence has a strong scouring effect on the wall surface of the heat exchange tubes. In addition, the elastic tube bundle itself has the ability of thermal compensation, and has the self-cleaning effect through thermal expansion and cold contraction, so it is not easy to scale. (3) There is no cold water area. When the water consumption is lower than the rated water supply capacity, the cold water at the bottom of the heating tank with high volume utilization rate will be gradually heated. At this time, there is no cold water area to maintain a large reserve of hot water. When the water consumption is greater than the rated water supply capacity, the hot water stored in the tank and the hot water immediately heated are simultaneously supplied to the outside to pass the peak water consumption. When the heating medium is stopped due to accidents or other reasons, the hot water stored can be supplied to a large extent.

The positive displacement heat exchanger is a heat exchanger that uses cold and hot fluids to alternately flow through the surface of the heat storage body (filler) in the heat storage chamber for heat exchange. The cold and hot fluids of the wall heat exchanger between the positive displacement heat exchangers are separated by the solid partition and heat exchange is carried out through the partition, so it is also called the surface heat exchanger.