US 4,646,535 AGranted

Temperature and pressure monitored refrigeration system

AssigneeNippondenso Co., Ltd.

InventorsAkio Matsuoka, Masashi Takagi, Akiro Yoshimi, Kazutoshi Nishizawa

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Abstract

A refrigeration system comprises a refrigeration cycle including a compressor of a variable capacity type for compressing a refrigerant and an evaporator for evaporating the compressed refrigerant. A driving source is connected to the compressor through a clutch movable between an engaged position and a disengaged position. A first detector detects pressure of the refrigerant evaporated by the evaporator to generate a signal. A second detector detects temperature relating to a cooling condition of the evaporator to generate a signal. A capacity control unit controls a discharge capacity of the compressor so as to cause the pressure detected by the first detector to approach an aimed pressure. A clutch control unit is operative in response to the signals from the respective first and second detectors to judge a condition of frosting on the evaporator for controlling the clutch for movement between the engaged and disengaged positions and to judge an insufficiency in quantity of the refrigerant in the refrigeration cycle for controlling the clutch for movement to the disengaged position.

Claims18

Dependent claims

A refrigeration system comprising:

a refrigeration cycle including a compressor having a variable capacity for compressing a refrigerant, and an evaporator connected to an inlet portion of said compressor to allow the refrigerant evaporated therein to be drawn into said compressor;
means for driving said compressor;
clutch means movable between two positions, for:
(1) in an engaged position, coupling said driving means to said compressor to allow the driving force from said driving means to be transmitted to said compressor, and (2) in a disengaged position, decoupling said driving means from said compressor to prevent the driving force from said driving means from being transmitted to said compressor;
first detecting means for detecting a pressure of the refrigerant evaporated by said evaporator to generate a signal representative of the pressure;
second detecting means for detecting a temperature relating to a cooling condition of said evaporator to generate a signal representative of the temperature;
capacity control means for controlling a discharge capacity of said compressor to cause the pressure detected by said first detecting means to approach an aimed pressure;
and
clutch control means operative in response to the signal from said first detecting means and the signal from said second detecting means for:
(1) judging whether frosting occurs on said evaporator, (2) moving said clutch means to said disengaged position when it is judged that said frosting occurs on said evaporator, (3) moving said clutch means to said engaged position when it is judged that no frosting occurs on said evaporator, (4) judging whether the refrigerant in said refrigeration cycle is insufficient in quantity and (5) moving said clutch means to said disengaged position when it is judged that the refrigerant in said refrigeration cycle is insufficient in quantity.

7 more elements

A refrigeration system comprising:

a refrigeration cycle including a compressor having a variable capacity for compressing a refrigerant, and an evaporator connected to an inlet port of said compressor to allow the refrigerant evaporated at said evaporator to be drawn into said compressor;
means for driving said compressor;
clutch means movable between two positions, for:
(1) in an engaged position, coupling said driving means to said compressor to allow the driving force from said driving means to be transmitted to said compressor, and (2) in a disengaged position, decoupling said driving means from said compressor to prevent the driving force from said driving means from being transmitted to said compressor;
first detecting means for detecting a pressure of the refrigerant evaporated by said evaporator to generate a signal representative of the pressure;
second detecting means for detecting a temperature relating to a cooling condition of said evaporator to generate a signal representative of the temperature;
capacity control means for controlling a discharge capacity of said compressor to cause the pressure detected by said first detecting means to approach an aimed pressure, said capacity control means determining said aimed pressure on the basis of the temperature detected by said second detecting means;
clutch control means operative in response to the signal from said first detecting means and the signal from said second detecting means for:
(1) judging whether frosting occurs on said evaporator, (2) moving said clutch means to said disengaged position when it is judged that the frosting occurs on said evaporator, (3) moving said clutch means to said engaged position when it is judged that no frosting occurs on said evaporator, (4) judging whether the refrigerant in said refrigeration cycle is insufficient in quantity, and (5) moving said clutch means to said disengaged position when it is judged that the refrigerant in said refrigeration cycle is insufficient in quantity.

6 more elements

A refrigeration system comprising:

a refrigeration cycle including a compressor having a variable capacity for compressing a refrigerant, and an evaporator connected to an inlet port of said compressor to allow the refrigerant evaporated at said envaporator to be drawn into said compressor;
means for driving said compressor;
clutch means movable between two positions, for:
(1) in an engaged position, coupling said driving means is to said compressor to allow the driving force from said driving means to be transmitted to said compressor, and (2) in a disengaged position, decoupling said driving means from said compressor to prevent the driving force from said driving means from being transmitted to said compressor;
first detecting means for detecting a pressure of the refrigerant evaporated by said evaporator to generate a signal representative of the pressure;
second detecting means for detecting a temperature relating to a cooling condition of said evaporator to generate a signal representative of the temperature;
third detecting means for detecting at least one physical parameter relating to a cooling load to generate a signal representative of the cooling load;
capacity control means operative in response to the signal from said second detecting means and the signal from said third detecting means to determine an aimed pressure for controlling a discharge capacity of said compressor to cause the pressure detected by said first detecting means to approach said aimed pressure;
and
clutch control means operative in response to the signal from said first detecting means and the signal from said second detecting means for:
(1) judging whether frosting occurs on said evaporator, (2) moving said clutch means to said disengaged position when it is judged that the frosting occurs on said evaporator, (3) moving said clutch means to said engaged position when it is judged that no frosting occurs on said evaporator, (4) judging whether the refrigerant in said refrigeration cycle is insufficient in quantity, and (5) moving said clutch means to said disengaged position when it is judged that the refrigerant in said refrigeration cycle is insufficient in quantity.

8 more elements

A refrigeration system comprising:

a refrigeration cycle including a compressor having a variable capacity for compressing a refrigerant, and an evaporator connected to a suction port of said compressor so as to allow the refrigerant evaporated at said evaporator to be drawn into said compressor;
means for driving said compressor;
clutch means movable between two positions, for:
(1) in an engaged position, coupling said driving means to said compressor to allow the driving force from said driving means to be transmitted to said compressor, and (2) in a disengaged position, decoupling said driving means from said compressor to prevent the driving force from said driving means from being transmitted to said compressor;
first detecting means for detecting a pressure of the refrigerant evaporated by said evaporator to generate a first signal representative of the pressure;
second detecting means for detecting a temperature relating to a cooling condition of said evaporator to generate a second signal representative of the temperature;
capacity control means for controlling a discharge capacity of said compressor to cause the pressure detected by said first detecting means to approach an aimed pressure;
and
clutch control means, operative in response to at least one of the first and second signals, for:
(1) determining whether frosting occurs on said evaporator, and (2) controlling said clutch means to move the same to said disengaged position when it is determined that frosting has occured on said evaporator;
wherein said capacity control means is also for determining said aimed pressure on the basis of the temperature detected by said second detecting means.

8 more elements

Dependencies are inferred from the claim text.