Apparatus for controlling refrigeration cycle and a method of controlling the same

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first operation means for changing a heat exchanging capability of said heat exchanger for condensation,
• second operation means for changing a heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor, and
• control means for reducing a difference between a running condition on a high pressure side or a low pressure side of said refrigeration cycle and a target,
• wherein said control means brings a temperature difference between an inlet temperature and an outlet temperature of a heat exchanging fluid in one of the heat exchangers for condensation and evaporation on a user side closer to a target temperature difference when the difference between said running condition on the high pressure side or the low pressure side and said target is reduced.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first operation means for changing a heat exchanging capability of said heat exchanger for condensation,
• second operation means for changing a heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor, and
• control means for reducing a difference between a running condition on a high pressure side or a low pressure side of said refrigeration cycle and a target
• wherein said control means minimizes energy consumption of the refrigeration cycle when the difference between said running condition on the high pressure side or the low pressure side and said target is reduced, and
• wherein said control means brings a temperature difference between an inlet temperature and an outlet temperature of a heat exchanging fluid in one of the heat exchangers for condensation and evaporation on a user side closer to a target temperature difference when the difference between said running condition on the high pressure side or the low pressure side and said target is reduced.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first operation means for changing a heat exchanging capability of said heat exchanger for condensation,
• second operation means for changing a heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor,
• control means for reducing a difference between a running condition on a high pressure side or a low pressure side of said refrigeration cycle and a target,
• target value setting means for automatically setting one of a target value representing one of said target of said running condition on the low pressure side and a target value representing said target of said running condition on the high pressure side with reference to a preset value of one of an inlet temperature and an outlet temperature of a heat exchanging fluid of one of said heat exchangers for condensation and evaporation on a user side;
• and
• wherein the other one of the target value representing said target of said running condition on the low pressure side and the target value representing said target of said running condition on the high pressure side is automatically set with reference to a temperature of a heat source.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first operation means for changing a heat exchanging capability of said heat exchanger for condensation,
• second operation means for changing a heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor, and
• control means for reducing a difference between a running condition on a high pressure side or a low pressure side of said refrigeration cycle and a target,
• target value setting means for automatically setting one of a target value representing one of said target of said running condition on the low pressure side and a target value representing said target of said running condition on the high pressure side with reference to a preset value of one of an inlet temperature and an outlet temperature of a heat exchanging fluid of one of said heat exchangers for condensation and evaporation on a user side;
• and
• wherein the other one of the target value representing said target of said running condition on the low pressure side and the target value representing said target of said running condition on the high pressure side is automatically set with reference to a temperature of a heat source,
• wherein said control means minimizes energy consumption of the refrigeration cycle when the difference between said running condition on the high pressure side or the low pressure side and said target is reduced.

A method of controlling a refrigeration cycle comprising steps of:

• making degrees of change of a plurality of capacities of a compressor to be parameters, said degrees of change are obtained from a change of running condition on a high pressure side or a low pressure side of the refrigeration cycle corresponding to a change of said plurality of capacities of the compressor,
• obtaining standard degrees of change of heat exchanging capabilities of a heat exchanger for condensation and a heat exchanger for evaporation to respectively bring said running conditions on the high pressure side and the low pressure side to their target values by respectively changing said heat exchanging capabilities of said heat exchangers for condensation and evaporation with respect to said degrees of change of said plurality of capacities of the compressor made as said parameters,
• respectively producing a plurality of degrees of change of said heat exchanging capabilities using said standard degrees of change of said heat exchanging capabilities of said heat exchangers for condensation and evaporation,
• operating said plurality of degrees of change so that these are respectively involved in ranges of said heat exchanging capabilities allowed for operating the refrigeration cycle when said plurality of degrees of change are not involved in said allowable ranges, and
• selecting degrees of change for bringing said running condition on the high pressure or low pressure side closer to its target value among said plurality of degrees of change of each of said heat exchanging capabilities obtained with respect to said plurality of capacities of the compressor as parameters.

A method of controlling a refrigeration cycle comprising steps of:

• operating each of standard degrees of change of a running capacity of a compressor, a heat exchanging capability of a heat exchanger for condensation, and a heat exchanging capability of a heat exchanger for evaporation for bringing a present running condition closer to a target value on a low pressure side or a high pressure side of the refrigeration cycle by changing said running capacity of the compressor and said heat exchanging capabilities of the heat exchangers for condensation and evaporation using a difference between said target on the low pressure side or the high pressure side and said present running condition,
• respectively producing a plurality of degrees of change from each of said standard degrees of change,
• repeating to produce said plurality of degrees of change so as to be respectively involved in ranges of said running capacity or said heat exchanging capabilities allowed for operating the refrigeration cycle when said plurality of degrees of change of said running condition of the compressor, the heat exchanger for evaporation, and the heat exchanger for condensation are not included in said ranges of said heat exchanging capabilities, and
• respectively selecting degrees of change for bringing said current running condition most closer to said target on the low or high pressure side among said reproduced plurality of degrees of change.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first controller of heat exchanging capability of said heat exchanger for condensation,
• second controller of heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor, and
• means for controlling any of said first controller, said second controller, and said means for operating and for reducing a difference between a running condition on either a high pressure side and a low pressure side of said refrigeration cycle and a target.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first controller of heat exchanging capability of said heat exchanger for condensation,
• second controller of heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor, and
• means for controlling any of said first controller, said second controller, and said means for operating and for reducing a difference between a running condition on either a high pressure side and a low pressure side of said refrigeration cycle and a target, wherein
• said control means brings a temperature difference between an inlet temperature and an outlet temperature of a heat exchanging fluid in one of the heat exchangers for condensation and evaporation on a user side closer to a target temperature difference when the difference between said running condition on the high pressure side or the low pressure side of said target is reduced.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first controller of heat exchanging capability of said heat exchanger for condensation,
• second controller of heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor, and
• means for controlling any of said first controller, said second controller, and said means for operating and for reducing a difference between a running condition on either a high pressure side and a low pressure side of said refrigeration cycle and a target,
• wherein said control means minimizes energy consumption of the refrigeration cycle when the difference between said running condition on the high pressure side or the low pressure side and said target is reduced, and
• wherein said control means brings a temperature difference between an inlet temperature and an outlet temperature of a heat exchanging fluid in one of the heat exchangers for condensation and evaporation on a user side closer to a target temperature difference when the difference between said running condition on the high pressure side or the low pressure side of said target is reduced.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first controller of heat exchanging capability of said heat exchanger for condensation,
• second controller of heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor,
• means for controlling any of said first controller, said second controller, and said means for operating and for reducing a difference between a running condition on either a high pressure side and a low pressure side of said refrigeration cycle and a target, and
• target value setting means for automatically setting one of a target value representing one of said target of said running condition on the low pressure side and a target value representing said target of said running condition on the high pressure side with reference to a preset value of one of an inlet temperature and an outlet temperature of a heat exchanging fluid of one of said heat exchangers for condensation and evaporation on a user side;
• and
• wherein the other one of the target value representing said target of said running condition on the low pressure side and the target value representing said target of said running condition on the high pressure side is automatically set with reference to a temperature of a heat source.

An apparatus for controlling a refrigeration cycle for circulating a refrigerant through a compressor, a heat exchanger for condensation, a flow rate control valve, and a heat exchanger for evaporation, connected to each other, comprising:

• first controller of heat exchanging capability of said heat exchanger for condensation,
• second controller of heat exchanging capability of said heat exchanger for evaporation,
• means for operating a running capacity for changing a running capacity of said compressor, and
• means for controlling any of said first controller, said second controller, and said means for operating and for reducing a difference between a running condition on either a high pressure side and a low pressure side of said refrigeration cycle and a target, and
• target value setting means for automatically setting one of a target value representing one of said target of said running condition on the low pressure side and a target value representing said target of said running condition on the high pressure side with reference to a preset value of one of an inlet temperature and an outlet temperature of a heat exchanging fluid of one of said heat exchangers for condensation and evaporation on a user side;
• and
• wherein said control means minimizes energy consumption of the refrigeration cycle when the difference between said running condition on the high pressure side or the low pressure side and said target is reduced, and the other one of the target value representing said target of said running condition on the low pressure side and the target value representing said target of said running condition on the high pressure side is automatically set with reference to a temperature of a heat source.