Samavirtalämmönvaihtimen

Samavirtalämmönvaihdin is a Finnish term referring to a parallel flow heat exchanger. In this type of heat exchanger, the two fluids involved flow in the same direction. This configuration is distinct from counter-current heat exchangers where the fluids flow in opposite directions. The design of a parallel flow heat exchanger influences its thermal performance and pressure drop characteristics.

The primary function of any heat exchanger is to transfer thermal energy from a hotter fluid to a colder fluid without direct mixing of the two fluids. In a samavirtalämmönvaihdin, the hot fluid enters at one end and flows alongside the colder fluid, which also enters at the same end and flows in the same direction. As the fluids travel through the exchanger, heat is transferred from the hot fluid to the cold fluid across a separating wall or surface.

The temperature difference between the two fluids tends to decrease along the length of the exchanger in a parallel flow design. This is because as the hot fluid cools and the cold fluid heats up, their temperatures converge. Consequently, the driving force for heat transfer, which is the temperature difference, diminishes over the entire length. This characteristic often leads to a lower overall thermal efficiency compared to a counter-current heat exchanger of the same size and with the same flow rates, as the average temperature difference is typically smaller. However, parallel flow designs can be simpler to construct in certain applications and may offer advantages in specific scenarios, such as minimizing thermal stress due to more uniform temperature gradients across the exchanger.