Transferring heat from relatively cold to relatively hot locations

Claim 3

A method according to claim 1 in which the absorbent liquid is recovered by overflow over a weir.

Claim 4

A method according to claim 1 comprising: rejecting heat from at least one of the working fluid and the absorbent liquid at the mixing step whereby to facilitate the formation of a solution of working fluid in the absorbent liquid.

Claim 5

A method according to claim 3 in which said heat rejection is effected by passing at least one of the working fluid and the absorbent liquid in a fourth heat exchange step in heat exchange relationship with a heat sink which is at a temperature t 4 lower than the temperature of at least one of the resulting heat-depleted working fluid and the absorbent liquid.

Claim 6

A method according to claim 4 in which the said heat sink to which heat is rejected comprises, at least in part, a solution of working fluid in absorbent liquid recovered from the mixing step.

Claim 7

A method according to claim 4 in which the said heat sink comprises a heat rejection sink selected from at least one of the cold heat source and the hot heat sink.

Claim 8

A method according to claim 1 in which recovered solution from the mixing step is passed in heat exchange with said absorbent liquid whereby the solution is heated to a temperature between t m and t c , and the absorbent liquid is cooled.

Claim 9

A method according to claim 1 in which working fluid substantially at the temperature t 1 and pressure p 1 is passed in heat exchange relationship with working fluid which has been recovered from the first heat exchange step whereby to heat the said recovered working fluid and to reduce the temperature of the working fluid passing to the first heat exchange step.

Claim 10

Apparatus for transferring heat from a relatively cold heat source at a temperature T c to a relatively hot heat sink at a temperature T s wherein T s exceeds T c comprising: a working fluid and an absorbent liquid selected to be capable of forming a solution having a lower solution temperature, t c ; a conduit for conducting said working fluid under a first pressure p 1 and at a first temperature t 1 to a first heat exchange means adapted for being in heat exchange relationship with the cold heat source via expansion means permitting expansion of the working fluid to a second pressure p 2 lower than p 1 and a second temperature t 2 lower than t 1 and lower than T c for extracting heat from the cold heat source; a conduit for the passage of working fluid from the first heat exchange means to mixing means operative for mixing the working fluid at a mixing pressure p m and mixing temperature t m not exceeding the lower solution temperature t c of the solution capable of being formed by said working fluid and absorbent liquid whereby to form a solution of working fluid in absorbent fluid; means for recovering said solution; means for causing the solution to pass at substantially the pressure p 1 exceeding p m and substantially at the mixing temperature t m to second heat exchange means adapted for being in heat exchange relationship with a source of heat operative to raise the temperature of the solution to a temperature t 3 which is greater than T s and greater than t c thereby forming a first liquid phase and a second liquid phase; liquid separating means connected for receiving the solution from the second heat exchange means for permitting the separation of said first liquid phase comprising working fluid from the second liquid phase comprising absorbent liquid; means for recovering said absorbent liquid depleted in working fluid, and for circulating said liquid to said mixing means for forming a further quantity of a solution of working fluid in absorbent liquid; means for conducting separated working fluid to pass to third heat exchange means adapted for being in heat exchange relationship with the hot heat sink whereby to furnish heat therefor, and means for conducting working fluid from said third heat exchange means substantially at said pressure p 1 and temperature t 1 for re-use in transferring further quantities of heat.

Claim 11

Apparatus for transferring heat from a relatively cold heat source at a temperature T c to a relatively hot heat sink at a temperature T s wherein T s exceeds T c comprising: a working fluid and an absorbent liquid selected to be capable of forming a solution having a lower solution temperature, t c ; a conduit for conducting said working fluid under a first pressure p 1 and at a first temperature t 1 to a first heat exchange means adapted for being in heat exchange relationship with the cold heat source via expansion means permitting expansion of the working fluid to a second pressure p 2 lower than p 1 and a second temperature t 2 lower than t 1 and lower than T c for extracting heat from the cold heat source; a conduit for the passage of working fluid from the first heat exchange means to mixing means operative for mixing the working fluid at a mixing pressure p m and mixing temperature t m not exceeding the lower solution temperature t c of the solution capable of being formed by said working fluid and absorbent liquid whereby to form a solution of working fluid in absorbent fluid; means for recovering said solution; means for causing the solution to pass at substantially the pressure p 1 exceeding p m and substantially at the mixing temperature t m to second heat exchange means adapted for being in heat exchange relationship with a source of heat operative to raise the temperature of the solution to a temperature t 3 which is greater than T s and greater than t c thereby forming a first liquid phase and a second liquid phase; liquid separating means connected for receiving the solution from the second heat exchange means for permitting the separation of said first liquid phase comprising working fluid from the second liquid phase comprising absorbent liquid; means for recovering said absorbent liquid depleted in working fluid, and for circulating said liquid to said mixing means for forming a further quantity of a solution of working fluid in absorbent liquid; means for conducting separated working fluid to pass to third heat exchange means adapted for being in heat exchange relationship with the hot heat sink whereby to furnish heat therefor, and means for conducting working fluid from said third heat exchange means substantially at said pressure p 1 and temperature t 1 for re-use in transferring further quantities of heat.

Claim 12

Apparatus according to claim 9 in which said separating means comprises an overflow weir means for the separation and recovery of absorbent liquid.

Claim 13

Apparatus according to claim 9 comprising a fourth heat exchange means for the passage of the solution at substantially the pressure p 1 and the temperature t m in heat exchange relationship with recovered depleted absorbent liquid whereby to cool the latter substantially to the mixing temperature t m and to heat the former to a temperature between t m and t c .

Claim 14

Apparatus according to claim 9 comprising fifth heat exchange means for the passage of working fluid substantially at temperature t 1 and pressure p 1 in heat exchange relationship with working fluid passing from the first heat exchange means to said mixing means whereby to heat the latter and cool the former.

Claim 15

Apparatus according to claim 9 comprising a pump for circulating solution recovered from the mixing means substantially at the mixing pressure p m to the second heat exchange means substantially at the pressure p 1 .

Claim 16

A method according to claim 1 in which the absorbent liquid is recovered by decantation.

Claim 17

Apparatus according to claim 9 in which said separating means comprises decantation means for the separation and recovery of absorbent liquid.

Claim 18

In an absorption refrigeration process wherein a working fluid is circulated through an evaporator to an absorber for absorption therein by an absorbent liquid and the working fluid in said absorbent liquid is subsequently heated and separated into a rich working fluid and an absorbent-rich liquid, the improvement comprising: employing a working fluid and an absorbent liquid which, within the range of thermodynamic conditions encountered in said absorber, are capable of forming a solution having a lower critical solution temperature, t c , and subsequently heating said solution to a temperature above t c whereby said solution forms a first liquid phase comprising a rich working fluid and a second liquid phase comprising an absorbent-rich liquid.

Claim 19

In an absorption refrigeration process wherein a working fluid is circulated through an evaporator to an absorber for absorption therein by an absorbent liquid and the working fluid in said absorbent liquid is subsequently heated and separated into a rich working fluid and an absorbent-rich liquid, the improvement comprising: employing a working fluid and an absorbent liquid which, within the range of thermodynamic conditions encountered in said absorber, are capable of forming a solution having a lower critical solution temperature, t c , and subsequently heating said solution to a temperature above t c whereby said solution forms a first liquid phase comprising a rich working fluid and a second liquid phase comprising an absorbent-rich liquid.