Refrigeration system and method

Claim 2

In a method of operating a refrigeration system of the type having an evaporator and an absorber connected in a closed circuit for normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator and normally being provided with absorbent solution for absorption of the vaporized refrigerant; means defining a chilling circuit for circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant; and means defining a cooling circuit for circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium; the steps of operating the absorber to condense the vaporized refrigerant, in the absence of absorbent solution in the absorber, by circulating the cooling medium in the second heatexchanger at a temperature lower than a temperature of the chilled fluid which will satisfy the refrigeration load; and circulating refrigerant condensed in the absorber to the evaporator.

Claim 3

In a method of operating a refrigeration system of the type having an evaporator and an absorber connected in a closed circuit for normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator and normally being provided with absorbent solution for absorption of the vaporized refrigerant; means defining a chilling circuit for circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant; and means defining a cooling circuit for circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium; the steps of removing absorbent solution from the absorber; operating the absorber to condense the vaporized refrigerant by circulating the cooling medium in the second heat-exchanger at a temperature lower than a temperature of the chilled fluid which will satisfy the refrigeration load; and conducting refrigerant condensed in the absorber to the evaporator.

Claim 4

In a method of operating a refrigeration system of the type having an evaporator and an absorber connected in a closed circuit for normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator and normally being provided with absorbent solution for absorption of the vaporized refrigerant; means defining a chilling circuit for circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant; and means defining a cooling circuit for circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium; the steps of removing absorbent solution from the absorber; operating the absorber to condense the vaporized refrigerant by circulating the cooling medium in the second heat-exchanger at a temperature lower than a temperature of the chilled fluid which will satisfy the refrigeration load; and conducting refrigerant condensed in the absorber to the evaporator.

Claim 5

In a method of operating a refrigeration system of the type having an evaporator, an absorber, a generator and a condenser connected in a closed circuit for normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator, the generator normally being operative to supply absorbent solution to the absorber for absorption of the vaporized refrigerant, the condenser normally being operative to supply condensed refrigerant to the evaporator; means defining a chilling circuit for circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant; and means defining a cooling circuit for circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium; the steps of removing absorbent solution from the absorber; operating the absorber to condense the vaporized refrigerant by circulating the cooling medium in the second heat-exchanger at a temperature lower than a temperature of the chilled fluid which will satisfy the refrigeration load; and circulating refrigerant condensed in the absorber to the evaporator; said steps being carried out with the generator and the condenser inoperative.

Claim 6

In a method of operating a refrigeration system of the type having an evaporator, an absorber, a generator and a condenser connected in a closed circuit for normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator, the generator normally being operative to supply absorbent solution to the absorber for absorption of the vaporized refrigerant, the condenser normally being operative to supply condensed refrigerant to the evaporator; means defining a chilling circuit for circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant; and means defining a cooling circuit for circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium; the steps of removing absorbent solution from the absorber; operating the absorber to condense the vaporized refrigerant by circulating the cooling medium in the second heat-exchanger at a temperature lower than a temperature of the chilled fluid which will satisfy the refrigeration load; and circulating refrigerant condensed in the absorber to the evaporator; said steps being carried out with the generator and the condenser inoperative.

Claim 7

The method according to claim 3, including the steps of discontinuing circulation of the condensed refrigerant from the absorber to the evaporator; charging the absorber with absorbent solution; commencing operation of the generator and the condenser; and circulating the cooling medium in the second heat-exchanger at a temperature higher than said temperature of the chilled fluid.

Claim 8

In a method of operating a refrigeration system of the type having an evaporator, an absorber, a generator and a condenser connected in a closed circuit normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator, the generator normally being operative to supply absorbent solution to the absorber for absorption of the vaporized refrigerant, the condenser normally being operative to supply condensed refrigerant to the evaporator; means defining a chilling circuit circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant, the temperature of the chilled fluid leaving the first heat-exchanger normally being maintained within a first range of values; means defining a cooling circuit circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium, the temperature of the cooling medium entering the second heat-exchanger normally being maintained within a second range of values having an upper limit higher than the upper limit of the first range; The steps of removing absorbent solution from the absorber; operating the absorber to condense the vaporized refrigerant by adjusting the temperature of the cooling medium entering the second heat-exchanger to a value lower than the temperature of the chilled fluid leaving the first heat-exchanger; and conducting refrigerant condensed in the absorber to the evaporator; said steps being carried out with the generator and the condenser inoperative.

Claim 9

In a method of operating a refrigeration system of the type having an evaporator, an absorber, a generator and a condenser connected in a closed circuit normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator, the generator normally being operative to supply absorbent solution to the absorber for absorption of the vaporized refrigerant, the condenser normally being operative to supply condensed refrigerant to the evaporator; means defining a chilling circuit circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant, the temperature of the chilled fluid leaving the first heat-exchanger normally being maintained within a first range of values; means defining a cooling circuit circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium, the temperature of the cooling medium entering the second heat-exchanger normally being maintained within a second range of values having an upper limit higher than the upper limit of the first range; The steps of removing absorbent solution from the absorber; operating the absorber to condense the vaporized refrigerant by adjusting the temperature of the cooling medium entering the second heat-exchanger to a value lower than the temperature of the chilled fluid leaving the first heat-exchanger; and conducting refrigerant condensed in the absorber to the evaporator; said steps being carried out with the generator and the condenser inoperative.

Claim 10

The method according to claim 5, including the steps of discontinuing circulation of the condensed refrigerant from the absorber to the evaporator; charging the absorber with absorbent solution, commencing operation of the generator and the condenser; and adjusting the temperature of the cooling medium entering the second heat-exchanger to a value within the second range and higher than the temperature of the chilled fluid leaving the first heat-exchanger.

Claim 11

In a method of operating a refrigeration system of the type having an evaporator, an absorber, a generator, and a condenser connected in a closed circuit normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator and normally to receive absorbent solution from the generator for absorption of the vaporized refrigerant; means defining a chilling circuit circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant, the temperature of the chilled fluid leaving the first heat-exchanger normally being maintained within a first range of values; means defining a cooling circuit circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium, the temperature of the cooling medium entering the second heat-exchanger normally being maintained within a second range of values having an upper limit higher than the upper limit of the first range; and means defining a heating circuit normally conducting flow of a heating medium and including a third heat-exchanger in the generator for normally abstracting heat from the heating medium and rejecting it to the absorbent solution; the steps of discontinuing operation of the generator and the condenser, and thereby interrupting the absorption refrigeration cycle, by discontinuing flow of the heating medium in the third heat-exchanger; removing absorbent solution from the absorber and the generator; operating the absorber to condense the vaporized refrigerant by adjusting the temperature of the cooling medium entering the second heat-exchanger to a value lower than the temperature of the chilled fluid leaving the first heat-exchanger; and circulating refrigerant condensed in the absorber to the evaporator.

Claim 12

In a method of operating a refrigeration system of the type having an evaporator, an absorber, a generator, and a condenser connected in a closed circuit normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator and normally to receive absorbent solution from the generator for absorption of the vaporized refrigerant; means defining a chilling circuit circulating a chilled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant, the temperature of the chilled fluid leaving the first heat-exchanger normally being maintained within a first range of values; means defining a cooling circuit circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium, the temperature of the cooling medium entering the second heat-exchanger normally being maintained within a second range of values having an upper limit higher than the upper limit of the first range; and means defining a heating circuit normally conducting flow of a heating medium and including a third heat-exchanger in the generator for normally abstracting heat from the heating medium and rejecting it to the absorbent solution; the steps of discontinuing operation of the generator and the condenser, and thereby interrupting the absorption refrigeration cycle, by discontinuing flow of the heating medium in the third heat-exchanger; removing absorbent solution from the absorber and the generator; operating the absorber to condense the vaporized refrigerant by adjusting the temperature of the cooling medium entering the second heat-exchanger to a value lower than the temperature of the chilled fluid leaving the first heat-exchanger; and circulating refrigerant condensed in the absorber to the evaporator.

Claim 13

The method according to claim 7, including the steps of discontinuing circulation of the condensed refrigerant from the absorber to the evaporator; returning the absorbent solution to the absorber and the generator; resuming operation of the generator and the condenser by resuming flow of the heating medium in the third heat-exchanger; and adjusting the temperature of the cooling medium entering the second heat-exchanger to a value within the second range and higher than the temperature of the chilled fluid leaving the first heat-exchanger.

Claim 14

In a refrigeration system including an evaporator and an absorber connected in a closed circuit for normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator and normally being provided with absorbent solution for absorption of the vaporized refrigerant; means defining a chilling circuit for circulating a chiLled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant; and means defining a cooling circuit for circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium; means for operating the absorber to condense the vaporized refrigerant, in the absence of absorbent solution in the absorber, when the temperature of the cooling medium entering the second heat-exchanger is lower than a temperature of the chilled fluid which will satisfy the refrigeration load, the last-mentioned means including bypass passage means communicating at one end thereof with the absorber and at the other end thereof with the evaporator, and bypass valve means associated with the bypass passage means for controlling flow therein, the bypass valve means having a normally closed position and being movable to an open position for the circulation of refrigerant condensed in the absorber to the evaporator.

Claim 15

In a refrigeration system including an evaporator and an absorber connected in a closed circuit for normally conducting a refrigerant and an absorbent solution in an absorption refrigeration cycle, the absorber being arranged in the closed circuit to receive refrigerant vaporized in the evaporator and normally being provided with absorbent solution for absorption of the vaporized refrigerant; means defining a chilling circuit for circulating a chiLled fluid in heat-exchange relation with a refrigeration load and including a first heat-exchanger in the evaporator for abstracting heat from the fluid and rejecting it to the refrigerant to chill the fluid and to vaporize the refrigerant; and means defining a cooling circuit for circulating a cooling medium and including a second heat-exchanger in the absorber for normally abstracting heat from the absorbent solution and rejecting it to the cooling medium; means for operating the absorber to condense the vaporized refrigerant, in the absence of absorbent solution in the absorber, when the temperature of the cooling medium entering the second heat-exchanger is lower than a temperature of the chilled fluid which will satisfy the refrigeration load, the last-mentioned means including bypass passage means communicating at one end thereof with the absorber and at the other end thereof with the evaporator, and bypass valve means associated with the bypass passage means for controlling flow therein, the bypass valve means having a normally closed position and being movable to an open position for the circulation of refrigerant condensed in the absorber to the evaporator.

Claim 16

The combination according to claim 9, including refrigerant distribution means in the evaporator for distributing unvaporized refrigerant over the first heat-exchanger; receptacle means in the evaporator below the first heat-exchanger for collecting unvaporized refrigerant; and refrigerant passage means connecting the distribution means and the receptacle means for conducting unvaporized refrigerant from the receptacle means to the distribution means; said other end of the bypass passage means communicating with the refrigerant passage means for circulation of condensed refrigerant from the absorber to the distribution means when the bypass valve means is in its open position.

Claim 17

The combination according to claim 10, wherein the refrigerant passage means includes a refrigerant pump having an inlet in communication with the receptacle means and an outlet in communication with the distribution means, the bypass passage means connecting the absorber and the refrigerant pump inlet.

Claim 18

The combination according to claim 11, wherein the bypass passage means includes an eductor having an outlet, a suction inlet, and a motive fluid inlet, the eductor outlet communicating with the pump inlet, the eductor suction inlet communicating with the absorber; motive fluid passage means connecting the pump outlet and the motive fluid inlet; and motive fluid valve means being associated with the motive fluid passage means for controlling flow therein; the motive fluid valve means having a normally closed position and being movable to an open position for operating the eductor to withdraw condensed refrigerant from the absorber when the bypass valve means is in its open position.

Claim 19

The combination according to claim 9, including means for removing absorbent solution from the absorber and comprising receiver means for storing the absorbent solution, said receiver means having an inlet, receiver passage means communicating at one end thereof with the receiver inlet, a solution pump having an inlet communicating with the absorber and having an outlet communicating with the other end of the receiver passage means, and receiver valve means associated with the receiver passage means for controlling flow therein, the receiver valve means having a normally closed position and being movable to an open position for removal of the absorbent solution from the absorber to the receiver means.

Claim 20

The combination according to claim 13, wherein said receiver means has an outlet, second receiver passage means communicating at one end thereof with the receiver outlet and at the other end thereof with the absorber, second receiver valve means being associated with the second receiver passage means for controlling flow therein, the second receiver valve means having a normally closed position and being movable to an open position for rEmoval of absorbent solution from the receiver means to the absorber.