Patent · US Expired

Pressure regulation in a transcritical refrigerant cycle

US7389648B2 · kind B2 · utility

10Cited by
7References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 4, 2004
Grant dateJun 24, 2008
Priority date
Expiry dateJan 15, 2026

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02B30/70
  • WIPO fieldThermal processes and apparatus
  • WIPO sectorMechanical engineering

Abstract

A refrigerant cycle is provided with a control for an expansion device to achieve a desired compressor discharge pressure. The system operates transcritically, such that greater freedom over compressor discharge pressure is provided. The system's efficiency is optimized by selecting an optimum discharge pressure. The optimum discharge pressure is selected based upon sensed environmental conditions, and the expansion device is adjusted to achieve the desired compressor discharge pressure. A feedback loop may be provided to sense the actual compressor discharge pressure and adjust the actual compressor discharge pressure by further refining the expansion device. The system is disclosed providing heated water based upon a demand for a particular hot water temperature. Further, the optimum discharge pressures may be determined experimentally, with an offset added to the experimentally determined value to ensure that the actual pressure is higher than the desired, or optimum pressure for the particular refrigerant cycle. In one embodiment, a formula is utilized to determine the optimum discharge pressure.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.