Digital controller for a cooling and heating plant having near-optimal global set point control strategy
US5963458A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 29, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Jul 29, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2700/21173
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A DDC controller is disclosed which implements a control strategy that provides for near-optimal global set points, so that power consumption and therefore energy costs for operating a heating and/or cooling plant can be minimized. Tile controller can implement two chiller plant component models expressing chiller, chilled water pump, and air handler fan power as a function of chilled water supply/return differential temperature. The models are derived from a mathematical analysis using relations from fluid mechanics and heat transfer under the assumption of a steady-state load condition. The analysis applies to both constant speed and variable speed chillers, chilled water pumps, and air handler fans. Similar models are presented for a heating plant consisting of a hot water boiler, hot water pump, and air handler fan which relates power as a function of the hot water supply/return differential temperature. A relatively simple technique is presented to calculate near-optimal chilled water and hot water set point temperatures whenever a new steady-state load occurs, in order to minimize total power consumption. From the calculated values of near-optimal chilled water and hot water …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.