High-temperature internal cascade heat pumps for industrial manufacturing applications especially distillations

A method of pumping heat from a heat source that is above ambient temperature to a heat sink that is above a temperature of the heat source, the method comprising:

• (i) providing a low-pressure gaseous stream of a mixed component containing two or more components with different boiling points;
• (ii) compressing the low-pressure gaseous stream to increase the pressure of the low-pressure gaseous stream to provide a high-pressure stream, which is predominantly a vapor or a gaseous stream;
• (iii) partially condensing the high-pressure stream by transferring heat to the heat sink from the high-pressure stream to provide a partially condensed two-phase stream;
• (iv) performing at least one separation and intermediate condensation step comprising:
• (a) separating the partially condensed two-phase stream into two streams including a separated liquid stream rich in heavier components and a separated vapor stream rich in lighter components,
• (b) subcooling the separated liquid stream from step (a) by transferring heat from the separated liquid stream and reducing the pressure of the separated liquid stream, and
• (c) condensing the separated vapor stream from step (a) by transferring heat from the separated vapor stream to provide a condensed separated vapor stream;
• (v) reducing the pressure of the condensed separated vapor stream after step (iv);
• (vi) vaporizing the condensed separated vapor stream of step (v) by transferring heat from the heat source to the condensed separated vapor stream to provide a vaporized stream;
• (vii) combining the vaporized stream with the separated liquid stream from step (iv) to provide a two-phase stream;
• and
• (viii) vaporizing the two-phase stream when transferring heat from the separated liquid stream and the separated vapor stream in step (iv) to provide the low-pressure gaseous mixed component stream of step (i).

A heat pump for pumping heat from a heat source that is above ambient temperature to a heat sink that is above the temperature of the heat source, the heat pump comprising:

• a compressor configured to compress a working fluid of a mixed component containing two or more components with different boiling points to increase the pressure of the working fluid before being partially condensed by transferring heat to the heat sink from the working fluid so that the working fluid is a two-phase stream;
• at least one separation and intermediate condensation unit in fluid and thermal communication with the heat sink to receive the two-phase stream of the working fluid, the separation and intermediate condensation unit comprising:
• a separator configured to separate the vapor and liquid phases of the two-phase stream of the working fluid into separate streams including a liquid stream that is rich in heavier components and a vapor stream that is rich in lighter components,
• an intermediate heat exchanger configured to transfer heat from the liquid stream and the vapor stream to condense the separated vapor stream and further cool the separated liquid stream, and
• an intermediate expansion valve in fluid communication with the intermediate heat exchanger to receive the liquid stream to reduce the pressure of the liquid stream;
• and
• an expansion valve in fluid communication with the intermediate heat exchanger of the at least one separate and intermediate condensation unit to receive the condensed vapor stream to reduce the pressure of the condensed vapor stream before being vaporized by transferring heat from the heat source to the working fluid so that the working fluid is a vaporized stream.