Heat pump with adaptive frost determination function
US4916912A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1988 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Oct 12, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25D21/02
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
The present invention is an adaptive method and apparatus for detecting the formation of frost in a heat pump. The compressor cycle is interrupted and a defrosting operation is begun if the difference between the exterior ambient temperature and exterior heat exchanger temperature exceeds a difference function of the exterior ambient temperature. The length this defrosting cycle is measured and the difference function is altered if the measured length deviates from a predetermined length of time. The frost formation difference function is initially set as a linear approximation. Thereafter the difference function value at the particular exterior ambient temperature is increased if the length the defrosting is greater than an upper limit value of six minutes and decreased if the length the defrosting is less than a lower limit value of four minutes. In the preferred embodiment, the exterior heat exchanger temperature is measured by a sensor and the exterior ambient temperature is determined once each compressor cycle from this measured temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.