Thermodynamic system and method communicating with exhaust devices of double-backpressure heat supply unit

The invention provides a thermodynamic system communicating with exhaust devices of a double-backpressure heat supply unit. The system comprises a low-pressure steam exhaust device and a high-pressure steam exhaust device, wherein the low-pressure steam exhaust device and the high-pressure steam exhaust device communicate through a communication master pipe, branch pipelines communicate with the communication master pipe and correspondingly are a first branch pipe, a second branch pipe and a third branch pipe, a communication master pipe turn-off valve is arranged on the communication master pipe, a first turn-off valve is arranged on the first branch pipe, a second turn-off valve is arranged on the second branch pipe, and a third turn-off valve is arranged on the third branch pipe. The invention further provides a method adopting the thermodynamic system communicating with the exhaust devices of the double-backpressure heat supply unit. According to the system and the method, the power generation power of th