Engine-driven heat pump chiller

A heat pump chiller (100) comprises: an air heat exchanger (3); a water heat exchanger (4); an operation switching mechanism (2) for switching between cold water operation and hot water operation; an engine exhaust heat recovery device (5); a second expansion valve (7) for regulating flow of the liquid state refrigerant toward the engine exhaust heat recovery device (5); a flow-direction control mechanism (8), a first expansion valve (6) and the second expansion valve (7) being disposed in parallel downstream of the refrigerant inlet of the flow-direction control mechanism (8); a flow regulating valve (33) for regulating the flow of the exhaust heat medium flowing in the engine exhaust heat recovery device (5); and a control device (50) for opening the second expansion valve (7) and the flow regulating valve (33) so that the refrigerant and exhaust heat medium flow in the exhaust heat recovery device (5) when the target value for the heat exchange volume in the water heat exchanger (4) is set equal to or lower than a prescribed value during cold water operation.