Refrigeration system with fiber optic sensing

• US 20070214812A1
• Filed: 03/20/2006
• Published: 09/20/2007
• Est. Priority Date: 03/20/2006
• Status: Active Grant

• Current Assignee: Hussmann Corporation (Panasonic Holdings Corporation)
• Original Assignee: Hussmann Corporation (Panasonic Holdings Corporation)
• Inventors: Madireddi, Sesha, Wagner, Dennis, Kolve, Michael
• Granted Patent: US 7,596,958 B2
• Time in Patent Office: Days
• US Class Current: 62/129
• CPC Class Codes: A47F 3/0482 Details common to both closed and open types
• CPC Class Codes: F25B 2400/22 Refrigeration systems for supermarkets
• CPC Class Codes: F25B 2700/11 Sensor to detect if defrost is necessary
• CPC Class Codes: F25D 2700/02 Sensors detecting door opening
• CPC Class Codes: F25D 29/008 Alarm devices

Abstract

A refrigeration case monitoring system. In one embodiment, the refrigeration case monitoring system includes a first fiber optic cable, a second fiber optic cable, and a control system having a first sensing channel and a second sensing channel. The first fiber optic cable transmits a signal that is indicative of a refrigeration case condition. The second fiber optic cable transmits a signal that is indicative of a second refrigeration case condition. The control system receives the signals from the first and second fiber optic cables using the first and second sensing channels, processes the signals, and provides an output related to the first and second refrigeration case conditions.

Claims

1. A refrigeration case monitoring system comprising:

a first fiber optic cable configured to transmit a signal indicative of a first refrigeration case condition;

at least one second fiber optic cable configured to transmit a signal indicative of a second refrigeration case condition; and

a control system having a first sensing channel and at least one second sensing channel, wherein the control system is configured to receive the signals from the first and at least one second fiber optic cables, process the signals, and generate an output related to the first and second refrigeration case conditions.

2. The monitoring system of claim 1, wherein the output is at least one of an audible signal and a visual signal.

3. The monitoring system of claim 1, wherein the control system is configured to interface with a controller.

4. The monitoring system of claim 1, wherein the control system comprises an analog-to-digital signal converter configured to process the signals received from the first and at least one second fiber optic cables.

5. The monitoring system of claim 1, wherein the control system comprises at least one amplifying circuit configured to amplify the signals received from the first and at least one second fiber optic cables.

6. The monitoring system of claim 1, wherein the signal indicative of the first refrigeration case condition at least partially depends on a light signal that is received by the first fiber optic cable.

7. The monitoring system of claim 6, wherein the light signal is received by the first fiber optic cable from a third fiber optic cable.

8. A refrigeration case monitoring system comprising:

at least one fiber optic cable configured to transmit a signal indicative of a refrigeration case condition;

a first controller having at least one sensing channel, wherein the first controller is configured to receive the signal from the at least one fiber optic cable, process the signal, and transmit a signal related to the refrigeration case condition; and

a second controller configured to be electrically connected to the first controller and to receive, from the first controller, the signal related to the refrigeration case condition and to generate an output related to the refrigeration case condition.

9. The refrigeration case monitoring system of claim 8, wherein the second controller is configured to control operations of the refrigeration case.

10. The refrigeration case monitoring system of claim 8, wherein the second controller is configured to provide a power supply to the first controller.

11. The refrigeration case monitoring system of claim 8, wherein the second controller is an integrated component of the refrigeration case monitoring system.

12. The refrigeration case monitoring system of claim 8, wherein the first controller includes a network port configured to be connected to an external electronic component.

13. A method of monitoring a refrigeration case, the method comprising:

monitoring, by at least one fiber optic sensor, a first and at least one second refrigeration case condition, wherein the first and at least one second refrigeration case conditions are of the group comprising,

an open door condition,

a frosted coil condition,

a fan failure condition,

a blocked drain condition, and

a lighting failure condition;

transmitting, by the at least one fiber optic sensor, a signal indicative of the refrigeration case condition;

receiving, by a control system having at least one sensing channel, the signal from the at least one fiber optic sensor;

processing, by the control system, the signal from the at least one fiber optic sensor, wherein processing the signal from the at least one fiber optic sensor includes conditioning the signal; and

generating, by the control system, an output indicative of the refrigeration case condition.

14. The method of claim 13, wherein conditioning the signal includes amplifying the signal.

15. The method of claim 13, wherein conditioning the signal includes converting the signal from an analog signal to a digital signal.

16. The method of claim 13, wherein processing the signal includes determining if the signal exceeds a predetermined threshold.

17. The method of claim 13, wherein processing the signal includes determining if the signal is less than a predetermined threshold.