Evacuated two-phase head-transfer systems

A heat-transfer system, in a gravitational field, for absorbing heat from one or more heat sources and for transferring the absorbed heat to one or more heat sinks;

• the system including a refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from the one or more heat sources at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the one or more heat sinks at least in part by changing from a vapor back into a liquid;
• (b) one or more hot heat exchangers for transmitting heat from the one or more heat sources to the refrigerant, the one or more hot heat exchangers including an evaporator for transmitting heat from a first heat source of the one or more heat sources to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator refrigerant passages is evaporated;
• (c) one or more cold heat exchangers for transmitting heat from the refrigerant to the one or more heat sinks, the one or more cold heat exchangers including a condenser for transmitting heat from the refrigerant to a first heat sink of the one or more heat sinks and for condensing refrigerant vapor;
• the condenser having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time;
• (d) one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive, the one or more evacuated refrigerant circuits comprising a refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the refrigerant-circuit configuration is active;
• the refrigerant principal circuit including
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor transfer means for transferring refrigerant vapor from the one or more evaporator refrigerant passages to the one or more condenser refrigerant passages, and
• (3) liquid-refrigerant principal transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the one or more evaporator refrigerant passages, and
• (e) one or more refrigerant pumps for circulating refrigerant around at least one of the one or more evacuated refrigerant circuits;
• the improvement in combination therewith comprising self-regulation means for regulating automatically, if and when operating conditions change, the refrigerant's flow in the one or more evacuated refrigerant circuits so that--with the one or more evacuated refrigerant circuits charged with an appropriate amount of refrigerant mass--the two self-regulation conditions recited next are satisfied, under steady-state conditions, for a preselected range of operating conditions comprising a preselected range of refrigerant evaporation rates which includes at least two refrigerant evaporation rates differing significantly from each other;
• (a) a first of the two self-regulation conditions requiring the amount of liquid refrigerant, in the one or more evaporator refrigerant passages, to be small enough to preclude refrigerant vapor, exiting the one or more evaporator refrigerant passages, being superheated by an amount exceeding a preselected superheat upper limit which may be chosen in essence equal to zero, and
• (b) a second of the two self-regulation conditions requiring each of the one or more refrigerant pumps to have an available net positive suction head high enough to preclude each of the one or more refrigerant pumps cavitating.

A heat transfer system, in a gravitational field, for absorbing heat from one or more heat sources and for transferring the absorbed heat to one or more heat sinks;

• the system including a refrigerant-circuit configuration comprising
• (a) a refrigerant for absorbing heat from the one or more heat sources at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the one or more heat sinks at least in part by changing from a vapor back into a liquid;
• (b) one or more hot heat exchangers for transmitting heat from the one or more heat sources to the refrigerant, the one or more hot heat exchangers including an evaporator for transmitting heat from a first heat source of the one or more heat sources to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having several heat-transfer surfaces which include one or more refrigerant-side heat-transfer surfaces, and also having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator passages is evaporated;
• (c) one or more cold heat exchangers for transmitting heat from the refrigerant to the one or more heat sinks, the one or more cold heat exchangers including a condenser for transmitting heat from the refrigerant to a first heat sink of the one or more heat sinks and for condensing refrigerant vapor;
• the condenser having several heat-transfer surfaces which include one or more refrigerant-side heat-transfer surfaces, and also having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time;
• (d) one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive, the one or more evacuated refrigerant circuits comprising a refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the refrigerant-circuit configuration is active;
• the refrigerant principal circuit including
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor transfer means for transferring refrigerant vapor from the one or more evaporator refrigerant passages to the one or more condenser refrigerant passages, and
• (3) liquid-refrigerant principal transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the one or more evaporator refrigerant passages;
• and
• (e) one or more refrigerant pumps for circulating refrigerant around at least one of the one or more evacuated refrigerant circuits, the one or more refrigerant pumps including a refrigerant principal pump having one or more refrigerant passages which are a part of the refrigerant principal circuit;
• and
• the improvement in combination therewith comprising self-regulation means for regulating automatically, if and when operating conditions change, the refrigerant's flow around the refrigerant principal circuits so that--with the one or more evacuated refrigerant circuits charged with an appropriate amount of refrigerant mass--at least the four self-regulation conditions recited next are satisfied, under steady-state conditions, for a preselected range of operating conditions comprising a preselected range of refrigerant evaporation rates which includes at least two refrigerant evaporation rates differing significantly from each other;
• (a) a first of the four self-regulation conditions requiring the amount of liquid refrigerant, in the one or more evaporator refrigerant passages, to be small enough to preclude refrigerant vapor, exiting the one or more evaporator refrigerant passages, being superheated by an amount exceeding a preselected superheat upper limit, which may be chosen in essence equal to zero,
• (b) a second of the four self-regulation conditions requiring refrigerant vapor entering the one or more condenser refrigerant passages to be essentially dry,
• (c) a third of the four self-regulation conditions requiring the amount of liquid refrigerant, backing-up into the one or more condenser refrigerant passages, to be small enough to preclude the area of the one or more condenser refrigerant-side heat-transfer surfaces, flooded by said backing-up liquid refrigerant, exceeding a preselected flood upper limit which may be chosen equal to zero, and
• (d) a fourth of the four self-regulation conditions requiring the refrigerant principal pump to have an available net positive suction head high enough to preclude the refrigerant principal pump cavitating.

A heat-transfer system, in a gravitational field, for absorbing heat from one or more heat sources and for transferring the absorbed heat to one or more heat sinks, the system including several refrigerant-circuit configurations;

• the several refrigerant-circuit configurations including a first refrigerant-circuit configuration comprising:
• (a) a first refrigerant for absorbing heat from a first heat source of the one or more heat sources at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to a first heat sink of the one or more heat sinks at least in part by changing from a vapor back into a liquid;
• (b) a first set of one or more hot heat exchangers for transmitting heat from the first heat source to the refrigerant, the first set of one or more hot heat exchangers including a first evaporator for transmitting heat from the first heat source to the first refrigerant and for evaporating liquid refrigerant;
• the first evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more first-evaporator refrigerant passages is evaporated;
• (c) a first set of one or more cold heat exchangers for transmitting heat from the first refrigerant to the first heat sink, the first set of one or more cold heat exchangers including a first condenser for transmitting heat from the first refrigerant to the first heat sink and for condensing refrigerant vapor;
• the first condenser having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more first-condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more first-evaporator refrigerant passages at the selfsame instant in time;
• (d) a first set of one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the first refrigerant-circuit configuration is active and essentially no air while the first refrigerant-circuit configuration is active and while the first refrigerant-circuit configuration is inactive, the first set of one or more evacuated refrigerant circuits comprising a first refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the first refrigerant-circuit configuration is active;
• the first refrigerant principal circuit including
• (1) the one or more first-evaporator refrigerant passages and the one or more first-condenser refrigerant passages,
• (2) refrigerant-vapor first transfer means for transferring refrigerant vapor from the one or more first-evaporator refrigerant passages to the one or more first-condenser refrigerant passages, and
• (3) liquid-refrigerant first principal transfer means for transferring liquid refrigerant from the one or more first-condenser refrigerant passages to the one or more first-evaporator refrigerant passages;
• and
• (e) a first set of one or more refrigerant pumps for circulating refrigerant around at least one evacuated refrigerant circuit of the first set of one or more evacuated refrigerant circuits;
• the several refrigerant-circuit configurations also including a second refrigerant-circuit configuration comprising:
• (a) a second refrigerant for absorbing heat from a second heat source of the one or more heat sources at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to a second heat sink of the one or more heat sinks at least in part by changing from a vapor back into a liquid;
• (b) a second set of one or more hot heat exchangers for transmitting heat from the second heat source to the refrigerant, the second set of the one or more hot heat exchangers including a second evaporator for transmitting heat from the second heat source to the second refrigerant and for evaporating liquid refrigerant;
• the second evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more second-evaporator refrigerant passages is evaporated;
• (c) a second set of one or more cold heat exchangers for transmitting heat from the second refrigerant to the second heat sink, the second set of one or more cold heat exchangers including a second condenser for transmitting heat from the second refrigerant to the second heat sink and for condensing refrigerant vapor;
• the second condenser having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more second-condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more second-evaporator refrigerant passages at the selfsame instant in time;
• and
• (d) a second set of one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the second refrigerant-circuit configuration is active and essentially no air while the second refrigerant-circuit configuration is active and while the second refrigerant-circuit configuration is inactive, the second set of the one or more evacuated refrigerant circuits comprising a second refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the second refrigerant-circuit configuration is active;
• the second refrigerant principal circuit including
• (1) the one or more second-evaporator refrigerant passages and the one or more second-condenser refrigerant passages,
• (2) refrigerant-vapor second transfer means for transferring refrigerant vapor from the one or more second-evaporator refrigerant passages to the one or more second-condenser refrigerant passages, and
• (3) liquid-refrigerant second principal transfer means for transferring liquid refrigerant from the one or more second-condenser refrigerant passages to the one or more second-evaporator refrigerant passages;
• the system also including first self-regulation means for regulating automatically, if and when operating conditions change, the first refrigerant's flow in the first refrigerant-circuit configuration's one or more evacuated refrigerant circuits so that--with the first refrigerant-circuit configuration's one or more evacuated refrigerant circuits charged with an appropriate amount of refrigerant mass--the two self-regulation conditions recited next are satisfied, under steady-state conditions, for a preselected range of operating conditions comprising a preselected range of refrigerant evaporation rates which includes at least two refrigerant evaporation rates differing significantly from each other;
• (1) a first of the two self-regulation conditions requiring the amount of liquid refrigerant, in the first evaporator's one or more refrigerant passages, to be small enough to preclude refrigerant vapor, exiting the first evaporator's one or more refrigerant passages, being superheated by an amount exceeding a preselected superheat upper limit which may be chosen in essence equal to zero, and
• (2) a second of the two self-regulation conditions requiring each refrigerant pump of the first set of one or more refrigerant pumps to have an available net positive suction head high enough to preclude each refrigerant pump of the first set of one or more refrigerant pumps cavitating.

A heat-transfer system, in a gravitational field, for absorbing heat from a heat source and for transferring the absorbed heat to one or more cold fluids;

• the system including a refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from the heat source at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the one or more cold fluids at least in part by changing from a vapor back into a liquid;
• (b) one or more hot heat exchangers for transmitting heat from the heat source to the refrigerant, the one or more hot heat exchangers including an evaporator for transmitting heat from the heat source to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator refrigerant passages is evaporated;
• (c) one or more cold heat exchangers for transmitting heat from the refrigerant to one or more heat-transfer fluids, the one or more cold heat exchangers including a condenser for transmitting heat from the refrigerant to the one or more heat-transfer fluids and for condensing refrigerant vapor;
• the condenser having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time;
• the condenser also having one or more component condensers, each of the one or more component condensers having one or more fluid ways for releasing heat to a heat-transfer fluid of the one or more heat-transfer fluids while the heat-transfer fluid flows through the condenser's one or more fluid ways;
• (d) one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive, the one or more evacuated refrigerant circuits comprising a refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the refrigerant-circuit configuration is active;
• the refrigerant principal circuit including
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor transfer means for transferring refrigerant vapor from the one or more evaporator refrigerant passages to the one or more condenser refrigerant passages, and
• (3) liquid-refrigerant principal transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the one or more evaporator refrigerant passages, and
• (e) one or more refrigerant pumps for circulating refrigerant around at least one of the one or more evacuated refrigerant circuits;
• the system also including one or more single-phase heat-transfer circuits equal in number to the one or more cold fluids, each of the one or more single-phase heat-transfer circuits comprising:
• (a) a first heat-transmitting means which is the selfsame unit as a component condenser of the condenser's one or more component condensers, and which has the selfsame one or more fluid ways as the component condenser's one or more fluid ways;
• (b) a second heat-transmitting means for transmitting heat from the heat-transfer fluid flowing through the component condenser's one or more fluid ways to a cold fluid of the one or more cold fluids;
• the second heat-transmitting means having a first set of one or more fluid ways for absorbing heat from said heat-transfer fluid while said heat-transfer fluid flows through the second heat-transmitting means' first set of one or more fluid ways, the second heat-transmitting means also having a second set of one or more fluid ways for releasing heat to the cold fluid while the cold fluid flows through the second heat-transmitting means' second set of one or more fluid ways;
• (c) first means for transferring said heat-transfer fluid from the component-condenser's one or more fluid ways to the second heat-transmitting means' first set of one or more fluid ways;
• and
• (d) second means for transferring said heat-transfer fluid from the second heat-transmitting means' one or more fluid ways to the component condenser's one or more fluid ways;
• the system also comprising self-regulation means for regulating automatically, if and when operating conditions change, the refrigerant's flow in the one or more evacuated refrigerant circuits so that--with the one or more evacuated refrigerant circuits charged with an appropriate amount of refrigerant mass--the two self-regulation conditions recited next are satisfied, under steady-state conditions, for a preselected range of operating conditions comprising a preselected range of refrigerant evaporation rates which includes at least two refrigerant evaporation rates differing significantly from each other;
• (a) a first of the two self-regulation conditions requiring the amount of liquid refrigerant, in the one or more evaporator refrigerant passages, to be small enough to preclude refrigerant vapor, exiting the one or more evaporator refrigerant passages, being superheated by an amount exceeding a preselected superheat upper limit which may be chosen in essence equal to zero, and
• (b) a second of the two self-regulation conditions requiring each of the one or more refrigerant pumps to have an available net positive suction head high enough to preclude each of the one or more refrigerant pumps cavitating;
• the system further including means for controlling the transfer of heat from the heat source to each of the one or more cold fluids.

A heat-transfer system, in a gravitational field, for absorbing heat from a heat source and for transferring the absorbed heat to one or more cold fluids;

• the system including a single-phase heat-transfer circuit comprising:
• (a) a heat-transfer fluid for absorbing heat from the heat source and for releasing the absorbed heat to one or more refrigerants;
• (b) first heat-transmitting means for transmitting heat from the heat source to one or more heat-transfer fluids;
• the first heat-transmitting means having one or more fluid ways for releasing heat to the heat-transfer fluid while the heat-transfer fluid flows through the first heat-transmitting means' one or more fluid ways;
• (c) second heat-transmitting means for transmitting heat from the heat-transfer fluid to one or more refrigerants;
• the second heat-transmitting means having one or more fluid ways for absorbing heat from the heat-transfer fluid while the heat-transfer fluid flows through the second heat-transmitting means' one or more fluid ways;
• and also having one or more component second heat-transmitting means, each component second heat-transmitting means of the second heat-transmitting means having one or more refrigerant passages wherein at least a portion of the refrigerant entering the one or more second heat-transmitting means' refrigerant passages is evaporated;
• the system also including one or more refrigerant-circuit configurations equal in number to the one or more cold fluids;
• each of the one or more refrigerant-circuit configurations comprising:
• (a) an evaporator which is the selfsame unit as a component second heat-transmitting means of the second heat-transmitting means' one or more component heat-transfer means, and which has the selfsame one or more refrigerant passages as the component second heat-transmitting means;
• (b) a condenser for transmitting heat from the refrigerant flowing through the component second heat-transmitting means' one or more refrigerant passage to a cold fluid of the one or more cold fluids;
• the condenser having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time, the condenser also having one or more fluid ways for releasing heat to the cold fluid while the cold fluid flows through the condenser's one or more fluid ways;
• the system also including self-regulation means for regulating automatically, if and when operating conditions change, the refrigerant's flow in the one or more evacuated refrigerant circuits so that--with the one or more evacuated refrigerant circuits charged with an appropriate amount of refrigerant mass--the two self-regulation conditions recited next are satisfied, under steady-state conditions, for a preselected range of operating conditions comprising a preselected range of refrigerant evaporation rates which includes at least two refrigerant evaporation rates differing significantly from each other;
• (a) a first of the two self-regulation conditions requiring the amount of liquid refrigerant, in the one or more evaporator refrigerant passages, to be small enough to preclude refrigerant vapor, exiting the one or more evaporator refrigerant passages, being superheated by an amount exceeding a preselected superheat upper limit which may be chosen in essence equal to zero, and
• (b) a second of the two self-regulation conditions requiring each of the one or more refrigerant pumps to have an available net positive suction head high enough to preclude each of the one or more refrigerant pumps cavitating;
• the system further including means for controlling the transfer of heat from the heat source to each of the one or more cold fluids.

A heat-transfer system, in a gravitational field, for absorbing heat from two heat sources and for transferring the absorbed heat to a heat sink;

• the system including a refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from a first heat source of the two heat sources at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the heat sink at least in part by changing from a vapor back into a liquid;
• (b) one or more hot heat exchangers for transmitting heat from the first heat source to the refrigerant, the one or more hot heat exchangers including an evaporator for transmitting heat from the first heat source to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator refrigerant passages is evaporated;
• (c) one or more cold heat exchangers for transmitting heat from the refrigerant to the heat sink, the one or more cold heat exchangers including a condenser for transmitting heat from the refrigerant to the first heat sink and for condensing refrigerant vapor;
• the condenser having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporation refrigerant passages at the selfsame instant in time;
• (d) one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive, the one or more evacuated refrigerant circuits comprising a refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the refrigerant-circuit configuration is active;
• the refrigerant principal circuit including
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor transfer means for transferring refrigerant vapor from the one or more evaporator refrigerant passages to the one or more condenser refrigerant passages, and
• (3) liquid-refrigerant principal transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the one or more evaporator refrigerant passages;
• and
• (e) one or more refrigerant pumps for circulating refrigerant around at least one of the one or more evacuated refrigerant circuits;
• the system also including self-regulation means for regulating automatically, if and when operating conditions change, the refrigerant's flow in the one or more evacuated refrigerant circuits so that--with the one or more evacuated refrigerant circuits charged with an appropriate amount of refrigerant mass--the two self-regulation conditions recited next are satisfied, under steady-state conditions, for a preselected range of operating conditions comprising a preselected range of refrigerant evaporation rates which includes at least two refrigerant evaporation rates differing significantly from each other;
• (1) a first of the two self-regulation conditions requiring the amount of liquid refrigerant, in the one or more evaporator refrigerant passages, to be small enough to preclude refrigerant vapor, exiting the one or more evaporator refrigerant passages, being superheated by an amount exceeding a preselected superheat upper limit which may be chosen in essence equal to zero, and
• (2) a second of the two self-regulation conditions requiring each of the one or more refrigerant pumps to have an available net positive suction head high enough to preclude each of the one or more refrigerant pumps cavitating;
• the system further including means other than a refrigerant-circuit configuration for transferring heat from a second heat source of the two heat sources to the heat sink;
• wherein at least one of the two heat sources cannot along always provide heat to the heat sink at the required rate;
• the system still further including means for controlling the second heat source so that the refrigerant-circuit configuration and said other means together provide heat to the heat sink at the required rate.

A heat-transfer system, in a gravitational field, for absorbing heat from a heat source and for transferring the absorbed heat to a heat sink;

• the system including a refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from the heat source at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the heat sink at least in part by changing from a vapor back into a liquid;
• (b) an evaporator for transmitting heat from the heat source to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator refrigerant passages is evaporated;
• (c) a condenser for transmitting heat from the refrigerant to the heat sink and for condensing refrigerant vapor;
• the condenser having one or more condenser refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time;
• (d) a refrigerant pump for causing refrigerant to flow in a desired direction, the refrigerant pump having one or more refrigerant passages;
• (e) one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive, the one or more evacuated refrigerant circuits comprising a refrigerant principal circuit including
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor transfer means for transferring refrigerant vapor from the one or more evaporator refrigerant passages to the one or more condenser refrigerant passages,
• (3) liquid-refrigerant first transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the refrigerant pump's one or more refrigerant passages, and
• (4) liquid-refrigerant second transfer means for transferring liquid refrigerant from the refrigerant pump's one or more refrigerant passages to the one or more evaporator refrigerant passages;
• the system also including
• (f) means for changing the effective capacity of the refrigerant pump as a function of a measure of the state of the refrigerant at a preselected location along the refrigerant-principal-circuit segment consisting of the one or more evaporator refrigerant passages and the refrigerant-vapor transfer means.

A heat-transfer system, in a gravitational field, for absorbing heat from a heat source and for transferring the absorbed heat to a heat sink;

• the system including a refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from the heat source at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the heat sink at least in part by changing from a vapor back into a liquid;
• (b) an evaporator for transmitting heat from the first heat source to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator refrigerant passages is evaporated;
• (c) a condenser for transmitting heat from the refrigerant to the first heat sink and for condensing refrigerant vapor;
• the condenser having one or more condenser refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages at an instant in time not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time;
• (d) means for separating the evaporated portion and the non-evaporated portion of refrigerant exiting the one or more evaporator refrigerant passages before said exiting refrigerant enters the one or more condenser refrigerant passages;
• (e) a refrigerant pump for causing refrigerant to flow in a desired direction, the refrigerant pump having one or more refrigerant passages;
• (f) several evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive;
• the one or more evacuated refrigerant circuits comprising
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor first transfer means for transferring, usually wet, refrigerant vapor from the one or more evaporator refrigerant passages to the separating means,
• (3) refrigerant-vapor second transfer means for transferring essentially dry refrigerant vapor from the separating means to the one or more condenser refrigerant passages,
• (4) liquid-refrigerant first transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the refrigerant pump's one or more refrigerant passages, and
• (5) liquid-refrigerant second transfer means for transferring liquid refrigerant from the refrigerant-pump's one or more refrigerant passages, and from the separating means, the one or more evaporator refrigerant passages, liquid refrigerant from the separating means being by-passed around the one or more condenser refrigerant passages and around the refrigerant pump's one or more refrigerant passages.

A heat-transfer system, in a gravitational field, for absorbing heat from a heat source and for transferring the absorbed heat to a heat sink;

• the system including a refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from the heat source at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the heat sink at least in part by changing from a vapor back into a liquid;
• (b) an evaporator for transmitting heat from the heat source to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator refrigerant passages is evaporated;
• (c) a condenser for transmitting heat from the refrigerant to the heat sink and for condensing refrigerant vapor;
• the condenser having one or more condenser refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time;
• (d) means for separating the evaporated portion and the non-evaporated portion of refrigerant exiting the one or more evaporator refrigerant passages before said exiting refrigerant enters the one or more condenser refrigerant passages;
• (e) a refrigerant pump for causing refrigerant to flow in a desired direction, the refrigerant pump having one or more refrigerant passages;
• (f) several evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive;
• the several evacuated refrigerant circuits comprising
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor first transfer means for transferring, usually wet, refrigerant vapor from the one or more evaporator refrigerant passages to the separating means,
• (3) refrigerant-vapor second transfer means for transferring essentially dry refrigerant vapor from the separating means to the one or more condenser refrigerant passages,
• (4) liquid-refrigerant first transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages, and from the separating means, to the refrigerant pump's one or more refrigerant passages, liquid refrigerant from the separating means being by-passed around the one or more condenser refrigerant passages, and
• (5) liquid-refrigerant second transfer means for transferring liquid refrigerant from the refrigerant pump's one or more refrigerant passages to the one or more evaporator refrigerant passages.

A closed heat-transfer system, in a gravitational field, for collecting solar radiant heat and for transferring the collected heat to a heat sink, the system including a refrigerant-circuit configuration comprising:

• (a) a refrigerant for absorbing the collected heat at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to the heat sink at least in part by changing from a vapor back into a liquid;
• (b) an evaporator for collecting and transmitting solar radiant heat to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more refrigerant passages is evaporated;
• (c) a condenser for transmitting heat from the refrigerant to the heat sink and for condensing refrigerant vapor;
• the condenser having one or more refrigerant passages wherein refrigerant vapor is condensed;
• the condenser having one or more refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages, at an instant in time, not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time;
• (d) a separator for separating the evaporated portion and the non-evaporated portion of refrigerant exiting the one or more evaporator refrigerant passages before said exiting refrigerant enters the one or more condenser refrigerant passages, the separator including a vessel for accumulating the non-evaporated portion of said exiting refrigerant;
• (e) a receiver for accumulating condensed refrigerant vapor exiting the one or more condenser refrigerant passages;
• (f) a refrigerant pump for transferring liquid refrigerant from the receiver to the one or more evaporator refrigerant passages;
• (g) several refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase;
• the several refrigerant circuits comprising
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor first transfer means for transferring, usually wet, refrigerant vapor from the one or more evaporator refrigerant passages to the separator vessel,
• (3) refrigerant-vapor second transfer-means for transferring essentially-dry refrigerant vapor from the separator vessel to the one or more condenser refrigerant passages,
• (4) liquid-refrigerant first transfer means for transferring condensed refrigerant vapor from the one or more condenser refrigerant passages to the receiver,
• (5) liquid-refrigerant second transfer means for transferring liquid refrigerant from the receiver to the refrigerant pump's one or more refrigerant passages,
• (6) liquid-refrigerant third transfer means for transferring liquid refrigerant from the refrigerant pump's one or more refrigerant passages to the one or more evaporator refrigerant passages,
• (7) liquid-refrigerant auxiliary transfer means for by-passing the non-evaporated portion of said exiting refrigerant, accumulating in the separator vessel, around the one or more condenser refrigerant passages and around the refrigerant pump's one or more refrigerant passages, and for transferring the by-passed non-evaporated portion of said exiting refrigerant to the one or more evaporator refrigerant passages;
• the system also including means for controlling the operation of the refrigerant pump so that the refrigerant pump
• (a) starts running when the level of liquid refrigerant in the receiver rises above a first preselected level, and
• (b) stops running when the level of liquid refrigerant in the receiver falls below a second preselected level lower than the first preselected level.

A heat-transfer system, in a gravitational field, for absorbing heat from a heat source, by one or more modes of heat transfer not limited exclusively to radiation heat transfer, and for transferring the absorbed heat to a heat sink;

• the system including a first refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from the heat source at least in part by changing to a vapor, and for releasing the absorbed heat to the heat sink at least in part by changing from a vapor back into a liquid;
• (b) one or more hot heat exchangers for transmitting heat from the heat source to the refrigerant, the one or more hot heat exchangers including an evaporator for transmitting heat from the heat source to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having several heat-transfer surfaces which include one or more refrigerant-side heat-transfer surfaces, and also having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator passages is evaporated;
• (c) one or more cold heat exchangers for transmitting heat from the refrigerant to the heat sink, the one or more cold heat exchangers including a condenser for transmitting heat from the refrigerant to the heat sink and for condensing refrigerant vapor;
• the condenser having several heat-transfer surfaces which include one or more refrigerant-side heat-transfer surfaces, and also having one or more condenser refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages at an instant in time not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time, and
• (d) one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the first refrigerant-circuit configuration is active and essentially no air while the first refrigerant-circuit configuration is active and while the first refrigerant-circuit configuration is inactive, the one or more evacuated refrigerant circuits comprising a refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the first refrigerant-circuit configuration is active;
• the refrigerant principal circuit including
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor transfer means for transferring refrigerant vapor from the one or more evaporator refrigerant passages to the one or more condenser refrigerant passages, and
• (3) liquid-refrigerant principal transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the one or more evaporator refrigerant passages;
• the improvement in combination therewith comprising self-regulation means for regulating automatically, if and when operating conditions change, the refrigerant's flow around the refrigerant principal circuit so that--with the one or more evacuated refrigerant circuits charged with an appropriate amount of refrigerant mass--at least the two self-regulation conditions recited next are satisfied, under steady-state conditions, for a preselected range of operating conditions comprising a preselected range of refrigerant evaporation rates which includes at least two refrigerant evaporation rates differing significantly from each other;
• (a) a first of the two self-regulation conditions requiring the amount of liquid refrigerant, in the one or more evaporator refrigerant passages, to be small enough to preclude refrigerant vapor, exiting the one or more evaporator refrigerant passages, being superheated by an amount exceeding a preselected superheat upper limit, which may be chosen in essence equal to zero,
• (b) a second of the two self-regulation conditions requiring the amount of liquid refrigerant, backing-up into the one or more condenser refrigerant passages, to be small enough to preclude the area of the one or more condenser refrigerant-side heat-transfer surfaces, flooded by said backing-up liquid refrigerant, exceeding a preselected flood upper limit which may be chosen equal to zero the self-regulation means not including a refrigerant valve having one or more refrigerant passages which are a part of the liquid-refrigerant principal transfer means.

A heat-transfer system, in a gravitational field, for absorbing heat from a heat source, not excluding the combustion gas of a fossil fuel, and for transferring the absorbed heat to a first set of one or more heat sinks;

• the system including a refrigerant-circuit configuration comprising:
• (a) a refrigerant for absorbing heat from the heat source at least in part by changing from a liquid to a vapor, and for releasing the absorbed heat to a heat sink of the first set of the one or more heat sinks at least in part by changing from a vapor back into a liquid;
• (b) one or more hot heat exchangers for transmitting heat from the heat source to the refrigerant, the one or more hot heat exchangers including an evaporator for transmitting heat from the heat source to the refrigerant and for evaporating liquid refrigerant;
• the evaporator having several heat-transfer surfaces which include one or more refrigerant-side heat-transfer surfaces, and also having one or more refrigerant passages wherein at least a portion of liquid refrigerant entering the one or more evaporator passages is evaporated;
• (c) one or more cold heat exchangers for transmitting heat from the refrigerant to the heat sink, the one or more cold heat exchangers including a condenser for transmitting heat from the refrigerant to a heat sink of the first set of the one or more heat sinks and for condensing refrigerant vapor;
• the condenser having several heat-transfer surfaces which include one or more refrigerant-side heat-transfer surfaces, and also having one or more condenser refrigerant passages wherein refrigerant vapor is condensed, the highest pressure at which condensation occurs in the one or more condenser refrigerant passages at an instant in time not exceeding the lowest pressure at which evaporation occurs in the one or more evaporator refrigerant passages at the selfsame instant in time, and
• (d) one or more evacuated refrigerant circuits containing refrigerant partly in the liquid phase and partly in the vapor phase while the refrigerant-circuit configuration is active and essentially no air while the refrigerant-circuit configuration is active and while the refrigerant-circuit configuration is inactive, the one or more evacuated refrigerant circuits comprising a refrigerant principal circuit around which the refrigerant circulates, not excluding intermittently, while the refrigerant-circuit configuration is active;
• the refrigerant principal circuit including
• (1) the one or more evaporator refrigerant passages and the one or more condenser refrigerant passages,
• (2) refrigerant-vapor transfer means for transferring refrigerant vapor from the one or more evaporator refrigerant passages to the one or more condenser refrigerant passages, and
• (3) liquid-refrigerant principal transfer means for transferring liquid refrigerant from the one or more condenser refrigerant passages to the one or more evaporator refrigerant passages;
• the improvement in combination therewith comprising means for controlling the system's heat source as a function of a measure of a parameter characterizing a thing other than the system's heat source.