# US 5,699,674 A · Method for controlling temperature in a chamber of a food storage apparatus

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- Number: US 5,699,674 A
- Document ID: US5699674A
- Status: Granted
- Kind: A
- Application number: 08/632,988
- Filed: 1996-04-16
- Granted: 1997-12-23
- Earliest claimed: 1995-05-10
- Assignees: Mando Machinery Corporation
- Inventors: Young-Gil Lee; Beom-Geol Ryu
- Web page: https://patentgrep.com/patent/US5699674A

## CPC

- F25D 29/00: Arrangement or mounting of control or safety devices
- G05D 23/1951: {with control of the working time of a temperature controlling device}
- F25B 2600/0251: with on-off operation
- F25D 2700/12: Sensors measuring the inside temperature
- F25D: REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR (refrigerated showcases A47F3/04; thermally-insulated vessels for domestic use A47J41/00; refrigerated vehicles, see the appropriate subclasses of classes B60 - B64; containers with thermal insulation in general B65D81/38; heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants, or materials for the production of heat or cold by chemical reactions other than by combustion C09K5/00; thermally-insulated vessels for liquefied or solidified gases F17C; air-conditioning or air-humidification F24F; refrigeration machines, plants, or systems F25B; cooling of instruments or comparable apparatus without refrigeration G12B)
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS

## Abstract

A method for controlling temperature in a chamber of a food storage apparatus comprises: (a) inputting a lower and an upper temperature limits T1 and T2, a predetermined elapsed time t1 of the chamber storing a normal amount of food needed for the temperature of the chamber to reach T1 after an initial activating of a cooling device, a predetermined temperature restoring time t3 for the temperature of the chamber to reach T2 from an initial deactivating of the chamber, a plurality of compensating values, and a plurality of reference values; (b) setting a variable A to T1; (c) activating the cooling device; (d) measuring an elapsed time t1' for the temperature of the chamber to reach T1 after an initial activating of the cooling device; (e) comparing the elapsed time t1' with t1' (f) setting the variable A to T1' if t1' is longer than t1; (g) deactivating the cooling device at an instant when the temperature of the chamber reaches the variable A; (h) activating the cooling device again at an instant when the temperature of the chamber is increased by .DELTA.T; (i) measuring a temperature restoring time t3' from the deactivating time to the subsequent activating time of the cooling device and comparing it with t3; (j) comparing a difference .DELTA.t3 between t3' and t3 with the reference values, and setting the variable A to one of the compensating values if t3' is less than t3, otherwise setting the variable A to T1.

## Claims

### Claim 1

A method for controlling temperature in a chamber of a food storage apparatus having a cooling device, the method comprising the steps of:
(a) inputting a lower and an upper temperature limit T1 and T2, a predetermined elapsed time t1 for the temperature of the chamber storing a normal amount of food to reach the lower temperature limit T1 after the cooling device has been initially activated, a predetermined temperature restoring time t3 needed for the temperature of the chamber storing the normal amount of food to be increased by a difference .DELTA.T between the lower and the upper temperature limits T1 and T2 from an initial deactivation of the cooling device, a plurality of compensating values, and a plurality of reference values;
(b) setting a variable A to the lower temperature limit T1;
(c) activating the cooling device for cooling the chamber of the food storage apparatus;
(d) measuring an elapsed time t1' for the temperature of the chamber to reach the lower temperature limit T1 after the cooling device has been activated initially;
(e) comparing the elapsed time t1' measured with the predetermined elapsed time t1;
(f) setting the value of the variable A to one of the compensating values if the elapsed time t1' measured is longer than t1;
(g) deactivating the cooling device at an instant when the temperature of the chamber reaches the value of the variable A;
(h) activating the cooling device again at an instant when the temperature of the chamber is increased by the difference .DELTA.T;
(i) measuring a temperature restoring time t3' of the chamber from the deactivating time to the subsequent activating time of the cooling device and comparing it with the predetermined temperature restoring time t3;
(j) comparing a difference .DELTA.t3 between the temperature restoring time t3' measured and the predetermined temperature restoring time t3 with the reference values, and setting the value of the variable A to one of the compensating values if t3' is less than t3, otherwise setting the value of the variable A to the lower temperature limit T1; and
(k) returning to step (g) if electric power to the food storage apparatus is not cut off.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the reference values are V1 and V2, where V1 is greater than V2, and the compensating values are T1', T1" and T1'", where (T1'T1"<T1"').

### Claim 3 (depends on 2)

The method according to claim 2, wherein if the temperature restoring time t3' measured is less than t3 and the difference .DELTA.t3 is larger than or equal to the first reference value V1, the cooling device is deactivated at an instant when the temperature of the chamber reaches the first compensating value T1'.

### Claim 4 (depends on 2)

The method according to claim 2, wherein if the temperature restoring time t3' measured is less than t3 and the difference .DELTA.t3 is less than V1 and larger than or equal to the second reference value V2, the cooling device is deactivated at an instant when the temperature of the chamber reaches the second compensating value T1".

### Claim 5 (depends on 2)

The method according to claim 2, wherein if the temperature restoring time t3' measured is less than t3 and the difference .DELTA.t3 is less than V2, the cooling device is deactivated at an instant when the temperature of the chamber reaches the third compensating value T1"'.

### Claim 6

A method for controlling temperature in a chamber of a food storage apparatus having a cooling device, the method comprising the steps of:
(a) inputting a lower and an upper temperature limits T1 and T2, a predetermined temperature restoring time t4 of the chamber storing a normal amount of food from T1 to T2 after an initial deactivation of the cooling device, a plurality of compensating values, and a plurality of reference values;
(b) setting a variable A to the lower temperature limit T1;
(c) activating the cooling device;
(d) deactivating the cooling device at an instant when the temperature of the chamber reaches the value of the variable A;
(e) activating the cooling device again at an instant when the temperature of the chamber reaches the upper temperature limit T2;
(f) measuring a temperature restoring time t4' of the chamber from T1 to T2 and comparing it with the predetermined temperature restoring time t4;
(g) comparing a difference .DELTA.t4 between the temperature restoring time t4' measured and the predetermined temperature restoring time t4 with the reference values, and setting the value of the variable A to one of the compensating values if t4' is less than t4, otherwise setting the value of the variable A to the lower temperature limit T1; and
(h) returning step (d) if electric power to the food storage apparatus is not cut off.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the reference values are V1 and V2 (V1>V2) and the compensating values are T1', T1" and T1'' (T1'<T1"<T1'').

### Claim 8 (depends on 7)

The method according to claim 7, wherein if the temperature restoring time t4' measured is less than t4 and the difference value .DELTA.t4 is larger than or equal to the first reference value V1, the cooling device is deactivated at an instant when the temperature of the chamber reaches the first compensating value T1'.

### Claim 9 (depends on 7)

The method according to claim 7, wherein if the temperature restoring time t4' measured is less than t4 and the difference value .DELTA.t4 is less than V1 and larger than or equal to the second reference value V2, the cooling device is deactivated at an instant when the temperature of the chamber reaches the second compensating value T1".

### Claim 10 (depends on 7)

The method according to claim 7, wherein if the temperature restoring time t4' measured is less than t4 and the difference value .DELTA.t4 is less than V2, the cooling device is deactivated at an instant when the temperature of the chamber reaches the third compensating value T1"'.