Rankine cycle apparatus and combined heat and power system

A Rankine cycle apparatus comprising:

• a pump that pressurizes a working fluid;
• an evaporator that heats the working fluid discharged from the pump;
• an expander that expands the working fluid heated in the evaporator;
• and
• a condenser that cools the working fluid discharged from the expander, wherein
• the evaporator comprises a plurality of heat transfer tubes arranged in rows in a flow direction of a high-temperature fluid to be heat-exchanged with the working fluid,
• when the heat transfer tube located in a most upstream row in the flow direction of the high-temperature fluid is defined as a most upstream heat transfer tube, the following requirement (A), (B) or (C) is satisfied:
• (A) the most upstream heat transfer tube forms an inlet of the evaporator so that the working fluid flows into the evaporator through the inlet and first passes through the most upstream heat transfer tube;
• (B) the rows comprise a first section and a second section, the first section including the most upstream heat transfer tube, and the second section including the heat transfer tubes other than the most upstream heat transfer tube so that the second section accepts the working fluid having passed through the first section and allows the working fluid to exchange heat with the high-temperature fluid in a counter-flow manner;
• and
• (C) the rows comprise a first section and a second section, the first section being composed of rows adjacent to each other and including the most upstream heat transfer tube in one of the rows and the heat transfer tube forming an inlet of the evaporator in a row other than the row of the most upstream heat transfer tube, and the second section being located downstream of the first section in the flow direction of the high-temperature fluid and accepting the working fluid having passed through the first section, and
• the working fluid has a thermal decomposition temperature lower than a temperature of the high-temperature fluid flowing on an outer peripheral surface of the most upstream heat transfer tube and is in a liquid phase or in a gas-liquid two phase when flowing in the most upstream heat transfer tube.