Diagnostic system for detecting faulty sensors in a refrigeration system

Patent · Tue Mar 31 00:00:00 EST 1987

OSTI ID:6609253

Hansen, J C; Ginder, H B; Johnson, L A

This patent describes a refrigeration system having a refrigeration circuit, including a condenser and an evaporator, through which refrigerant flows and having first and second operating variables which are sensed by first and second sensors, respectively. The variables have a predetermined relationship with respect to each other as a result of which the sensor outputs also have a predetermined relationship with respect to each other when the sensors are functioning properly. A diagnostic system is described for detecting when either one of the sensors is faulty, comprising: means for developing, from the output of the first sensor, a first signal representing the first variable; means for developing, from the output of the second sensor, a second signal representing the second variable; computing means for determining, from the difference between the first and second signals, if an impossible relationship exists between the sensor outputs and thus between the first and second variables, thereby indicating that the output of at least one of the sensors is in error and that the sensor is therefore faulty; and warning means, controlled by the computing means, for providing a warning message to operating personnel when a faulty sensor is detected.

• Assignee: NOV; NOV-87-055326; EDB-87-087617
• Patent Number(s): US 4653280
• OSTI ID: 6609253
• Resource Relation: Patent File Date: Filed date 18 Sep 1985
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
BUILDINGS
REFRIGERATORS
COMPUTERIZED CONTROL SYSTEMS
DIAGNOSTIC TECHNIQUES
CONDENSERS
ERRORS
EVAPORATORS
FAILURE MODE ANALYSIS
FAILURES
FLUID FLOW
MONITORS
REFRIGERANTS
SIGNALS
CONTROL SYSTEMS
FLUIDS
MEASURING INSTRUMENTS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
WORKING FLUIDS
320106* - Energy Conservation
Consumption
& Utilization- Building Equipment- (1987-)