Heat-pump water heater
US6430949B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 18, 2001 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Apr 18, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B30/70
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
In a heat-pump water heater, an ECU sets a target temperature difference between water flowing into a water heat exchanger and refrigerant flowing out from the water heat exchanger, and controls a valve opening degree of an expansion valve so that the target temperature difference is obtained. When a refrigerant temperature discharged from a compressor is higher than a predetermined value, the target temperature difference is increased until the refrigerant temperature discharged from the compressor becomes lower than the predetermined value. Further, when water-heating capacity is decreased due to the increase of the target temperature difference, a rotation speed of the compressor is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.