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:
Aug. 23, 2016
Filed:
Dec. 21, 2009
Lee R. Cline, West Salem, WI (US);
Michael C. A. Schwedler, La Crosse, WI (US);
Susanna S. Hanson, La Crosse, WI (US);
Brian J. Fiegen, Onalaska, WI (US);
Lee R. Cline, West Salem, WI (US);
Michael C. A. Schwedler, La Crosse, WI (US);
Susanna S. Hanson, La Crosse, WI (US);
Brian J. Fiegen, Onalaska, WI (US);
TRANE INTERNATIONAL INC., Davidson, NC (US);
Abstract
A multi-mode, bi-directional cascade heat pump system, according to some examples, includes at least two chillers each being part of a unidirectional refrigerant circuit. The system includes heat exchangers each of which are dedicated to operate as just a condenser or as just an evaporator, regardless of the system's operating mode. In some modes, a secondary fluid transfers heat between the condenser of one chiller and the evaporator of another chiller before the fluid returns to a secondary fluid source such as, for example, a geothermal borefield or a conventional water source. In some embodiments, fluid is withdrawn from a borefield by way of a pump having a speed that varies to maintain a desired fluid temperature and/or a desired heat transfer rate at the borefield. The heat pump system includes means for minimizing flow through the borefield and for minimizing unnecessary mixing of relatively high and low temperature fluid.