Abstract: A heat exchanger is provided. The heat exchanger comprises an evaporator, a vapor-liquid separator, a liquid level sensor and a controller. The evaporator is used for heating a working fluid up to a vapor-liquid state, and has a working fluid inlet pipe and a working fluid outlet pipe. The vapor-liquid separator is connected to the working fluid outlet pipe for separating the working fluid into a vapor working fluid and a liquid working fluid. The liquid level sensor detects a level of the liquid working fluid inside the vapor-liquid separator and outputs a liquid level signal. The controller receives the liquid level signal and controls the vapor quality of the working fluid inside the evaporator.

Abstract: A heat exchanger with recuperating and condensing functions is provided. The heat exchanger includes a pressure vessel, a recuperating pipe and a cooling stream pipe. The pressure vessel has an inlet, an outlet and a baffle. The baffle, located between the inlet and the outlet, divides the interior of the pressure vessel into a working fluid recuperating region and a working fluid condensing region. The recuperating pipe is disposed in the pressure vessel, and passes through the working fluid recuperating region to heat a liquid working fluid flowing through the recuperating pipe. The cooling stream pipe is disposed in the pressure vessel, and passes through the working fluid condensing region to cool a vapor working fluid flowing into the pressure vessel. The vapor working fluid passes through the working fluid recuperating region and then flows into the working fluid condensing region.