FLUID LEVEL MEASUREMENT SYSTEM AND METHOD

• US 20150177047A1
• Filed: 03/04/2015
• Published: 06/25/2015
• Est. Priority Date: 04/01/2010
• Status: Abandoned Application

• Current Assignee: Thermo King Corporation (Trane Technologies plc)
• Original Assignee: Thermo King Corporation (Trane Technologies plc)
• Inventors: Sanders, Russell L., McReynolds, Anthony J., Hochstein, Randy, Muralidhar, Ashok
• Application Number:
  US14/637,679
• Publication Number:
  US 20150177047A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01F 23/2962 Measuring transit time of reflected waves
• CPC Class Codes: G01F 23/2968 Transducers specially adapted for acoustic level indicators
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A transport refrigeration system for a transportable temperature controlled space includes a compressor, a condenser and an evaporator fluidly connected to one another, an engine operatively connected to the compressor, and a fuel tank assembly fluidly connected to the engine. The fuel tank assembly includes a fuel tank configured to contain the fuel, a fuel vapor and air, and an ultrasonic fluid level sensor for sensing a level of fuel, the fuel tank having a maximum fuel level. The fluid level sensor includes a transducer having a ring period. The distance from the fluid level sensor to the maximum fuel level is at least half the distance that the sound travels through the fuel vapor and air during the ring period of the transducer.

Claims

1-11. -11. (canceled)

12. A method for positioning an ultrasonic fluid level sensor in a tank assembly of a transport refrigeration system (TRS), the TRS including a compressor, a condenser, and an evaporator fluidly connected, an engine operatively connected to the compressor, a tank containing a fluid, a fluid vapor, and air, wherein the fluid level sensor includes a transducer having a ring period, the method comprising:

calculating a near field distance of the fluid level sensor, wherein the near field distance is based on the speed of sound through the fluid vapor during the ring period of the transducer;

determining a maximum fluid level in the tank; and

positioning the fluid level sensor at a distance from the maximum fluid level that is greater than or equal to half the near field distance, wherein the positioning includes directing the fluid level sensor toward a surface of the fluid such that sound from the fluid level sensor is reflected from the surface of the fluid.

13. The method of claim 12, wherein positioning the fluid level sensor includes providing a spacer between the fluid level sensor and the maximum fluid level.

14. The method of claim 12, wherein positioning the fluid level sensor includes:

providing a spacer adjacent the fluid level sensor, the spacer extending into an interior of the tank assembly, and

providing fluid vapor and air inside the spacer for spacing a surface of the fluid from the fluid level sensor.

15. The method of claim 12, wherein the near field distance is calculated using the equation D_nf=V_sd*T_t, where D_nf is the near field distance, V_sd is the speed of sound through the fluid vapor and air, and T_t is the ring period of the transducer.

16. The method of claim 12, wherein the fluid is fuel and the fluid vapor is fuel vapor.