Method for operating a thermodynamic cycle, and thermodynamic cycle

A thermodynamic circuit comprising:

• a first heat exchanger for producing a first heated or partially vaporized working medium flow by heating or partially vaporizing a pressurized liquid working medium flow received directly from a pump by heat transfer from an expanded working medium flow;
• a second heat exchanger for producing a second at least partially vaporized working medium flow by at least partially vaporizing or further vaporizing the first working medium flow with heat which is transferred from an external heat source;
• a third heat exchanger for completely condensing the expanded working medium flow, wherein the completely condensed working medium flow is delivered to the pump;
• a first separator for separating a liquid phase from a vapor phase of the second working medium flow;
• an expansion device for expanding the vapor phase, converting its energy to a usable form, and producing an expanded vapor phase;
• a first combination point for producing the expanded working medium flow by combining the liquid phase and the expanded vapor phase;
• a working medium flow homogenizing system arranged between the first heat exchanger and the third heat exchanger, the working medium flow homogenizing system comprising:
• an additional separator configured to separate a liquid phase from a vapor phase of the working medium flow, wherein all of the liquid phase from the additional separator enters the third heat exchanger;
• and
• a mixer for combining the separated liquid phase and vapor phase output by the additional separator in a manner that homogenizes the working medium flow;
• and
• a valve system configured to be switched between:
• a first configuration in which the separated liquid phase is routed to bypass the expansion device and pass through the first heat exchanger and the separated vapor phase is routed through the expansion device;
• a second configuration in which the separated liquid phase is passed through the first heat exchanger, and the separated vapor phase is routed through a bypass line which branches off from a line between the first separator and the expansion device at a branching point, bypasses the expansion device and the first heat exchanger, and opens into a line between the first heat exchanger and the third heat exchanger at a second combination point downstream of the first heat exchanger and upstream of working medium flow homogenizing system to combine with the separated liquid phase heated by the first heat exchanger and form a partially-condensed cooled-down working medium flow, such that downstream of the mixer, the working medium flow homogenizing system homogenizes the combined liquid phase and vapor phase of the partially-condensed cooled-down working medium flow;
• and
• a third configuration directing the vapor phase to both the first heat exchanger and the expansion device for regular operation without the bypass after the circuit has been fully started up.

A system for operating a thermodynamic circuit comprising:

• a first heat exchanger for producing a first heated or partially vaporized working medium flow by heating or partially vaporizing a pressurized liquid working medium flow received directly from a pump by heat transfer from an expanded working medium flow;
• a second heat exchanger for producing a second at least partially vaporized working medium flow by at least partially vaporizing or further vaporizing the first working medium flow with heat which is transferred from an external heat source;
• a third heat exchanger for completely condensing the expanded working medium flow, the completely condensed working medium flow being delivered to the pump;
• a first separator for separating a liquid phase from a vapor phase of the second working medium flow;
• an expansion device, in particular a turbine, for expanding the vapor phase, converting its energy to a usable form, and producing an expanded vapor phase;
• a first combination point for producing the expanded working medium flow by combining the liquid phase and the expanded vapor phase;
• a working medium flow homogenizing system arranged between the first heat exchanger and the third heat exchanger, the working medium flow homogenizing system comprising:
• an additional separator configured to separate a liquid phase from a vapor phase of the working medium flow, wherein all of the liquid phase from the additional separator enters the third heat exchanger;
• and
• a mixer for combining the separated liquid phase and vapor phase output by the additional separator in a manner that homogenizes the working medium flow;
• wherein the system is configured, in order to start the circuit:
• to separate the vapor phase by the first separator, wherein the vapor phase bypasses the expansion device and the first heat exchanger,
• to supply the liquid phase, which has been separated by the first separator, via the first combination point to the first heat exchanger, where the liquid phase is cooled down by heat transfer to the liquid working medium flow, and
• after the first heat exchanger, to combine the cooled-down separated liquid phase and the separated vapor phase at a second combination point downstream of the first heat exchanger and upstream of working medium flow homogenizing system that is arranged upstream of the third heat exchanger to form a partially-condensed cooled-down working medium flow, such that the working medium flow homogenizing system homogenizes the combined liquid phase and vapor phase of the partially-condensed cooled-down working medium flow, and such that between the first separator and the second combination point, the separated liquid phase passes through the first heat exchanger and the separated vapor phase bypasses both the expansion device and the first heat exchanger;
• and
• wherein the system is configured, after the circuit has been fully started up, to direct the vapor phase to both the first heat exchanger and the expansion device for regular operation without the bypass.