Preheater for compressor

Patent metadata

Field	Value
Publication number	US-10514025-B2
Application number	US-201515520232-A
Country	US
Kind code	B2
Filing date	Dec 4, 2015
Priority date	Dec 10, 2014
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

A preheater for a compressor that is capable of heating a lubricant oil efficiently with smaller power is provided. A preheater for a compressor includes: a capacitive oil surface sensor that is provided at a compressor used in a refrigerating cycle, and detects an oil surface of a lubricant oil A in the compressor; and a power supply unit that applies high-frequency voltage to the oil surface sensor.

First claim

The invention claimed is:

1. A preheater for a compressor, comprising:
a capacitive oil surface sensor comprising a pair of electrodes provided in the compressor used in a refrigerating cycle, and detecting an oil surface of a lubricant oil in the compressor by detecting any change in a capacitance between the pair of electrodes;
a power supply that supplies frequency voltage signals having a predefined frequency to a switch that switches
between a first mode that provides the voltage signals from the power supply to a compressor motor driver circuit and a second mode that provides the voltage signals to the capacitive oil surface sensor, according to a predetermined preheating condition; and
a controller for controlling the compressor motor driver circuit, wherein
the capacitive oil surface sensor heats the lubricant oil by dielectric heating when the voltage signals are supplied to the oil surface sensor,
the power supply includes an oscillator circuit that generates the frequency voltage signals, and
the controller uses the voltage signals received via the switch as a clock signal to control the compressor motor driver circuit.

2. The preheater for a compressor according to claim 1 , wherein the frequency voltage signals are supplied to the capacitive oil surface sensor during a halt of the compressor.

3. The preheater for a compressor according to claim 1 , wherein the oscillator circuit is disposed near the capacitive oil surface sensor such that a line length from the compressor to the oscillator circuit, or to the switch is 50 cm or shorter.

Assignees

• Daikin Ind Ltd

Inventors

• Ishizeki Shinichi
• Doumae Hiroshi
• Kishiwaki Yuusuke
• Fujiwara masahide
• Ikeda Motonobu

Classifications

• F25B2700/03

  Oil level · CPC title

• F25B1/00

  Compression machines, plants or systems with non-reversible cycle (F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence) · CPC title

• F25B2600/024

  by controlling the electric parameters, e.g. current or voltage · CPC title

• F04B39/04 Primary

  Measures to avoid lubricant contaminating the pumped fluid · CPC title

• F25B2700/04

  Refrigerant level · CPC title