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:
Jun. 27, 1989
Filed:
Nov. 04, 1987
Yukio Fukayama, Kure, JP;
Atsushi Kuramoto, Fukuoka, JP;
Babcock-Hitachi Kabushiki Kaisha, Tokyo, JP;
Abstract
A boiler control system includes a first device for measuring or computing a rate of change in steam temperature and a generated thermal stress in a pressure part of a boiler, and a second device for controlling steam temperature or a rate of change in the steam temperature at the pressure part of the boiler in accordance with a desired value, and a third device which has functions for storing in a memory combinations of the steam temperature and the thermal stress at each moment as obtained by the first device. The third device determining, from the combinations stored in the memory, a relationship between a steam temperature changing rate and a maximum thermal stress caused by the steam temperature chaning rate, determines, in accordance with the relationship, a steam temperature changing rate limit value necessary for maintaining an actual thermal stress in the pressure part of the boiler below a maximum thermal stress limit value which is predetermined beforehand or which is given for each start-up of the boiler, and delivers the steam temperature changing rate limit value or desired steam temperature value obtained by integrating the steam temperature changing rate limit value to the second device as the desired value.