The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 07, 1989
Filed:
Feb. 27, 1989
Thomas J Beckey, Edina, MN (US);
Lorne W Nelson, Bloomington, MN (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
A method for improving cooling of a compressor element used in an air conditioning system and having a refrigerant compressor and associated drive motor hermetically sealed in a fluid-tight shell includes the steps of detecting an excessive increase in the temperature of the compressor element, intermittently operating the system during the excessive temperature detection with a superheat of a refrigerant in the system below zero superheat degrees to concurrently allow liquid refrigerant to enter the shell to enhance the cooling of the compressor apparatus by the latent heat of vaporization of the liquid refrigerant and terminating the intermittent operation and the admittance of the liquid refrigerant into the compressor element upon a detection of a desired temperature of operation of the compressor element. An air conditioning apparatus utilizing this method includes a device for introducing an intermittent perturbation into the control of an expansion valve located in a refrigerant flow line in the air conditioning apparatus. The control of this valve is based on a desired superheat of the refrigerant. The device may include either the introduction of a cyclic or sinusoidal variation in a superheat setpoint used for control of the expansion valve or the introduction of a cyclic variation in the gain of a superheat controller having an output signal controlling the expansion valve.