Boiler system

Patent metadata

Field	Value
Publication number	US-9618197-B2
Application number	US-201314416546-A
Country	US
Kind code	B2
Filing date	Feb 28, 2013
Priority date	Feb 22, 2013
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

The invention improves system efficiency with no waste of heat held by a stopped boiler. A boiler system includes a boiler group having a plurality of boilers and a controller for controlling a combustion state of the boiler group. The controller includes a heat release determiner for determining whether or not the plurality of boilers includes a boiler releasing heat, a boiler increase determiner for determining, when the heat releasing boiler starts combustion and the heat releasing boiler and the other combusting boilers are combusted at equal load factors, whether or not the load factor is higher than a predetermined load factor, and an output controller for combusting the heat releasing boiler when the load factor is determined to be higher than the predetermined load factor.

First claim

The invention claimed is:

1. A boiler system comprising a boiler group including at least three boilers each configured to combust at a varied load factor which represents a rate of an amount of combustion with respect to a maximum amount of combustion of a boiler, and a controller for controlling a combustion state of the boiler group in accordance with an amount of steam required by a user apparatus, wherein
the controller includes
a determiner for determining a heat releasing boiler configured to determine that a heat releasing boiler exists among the plurality of boilers, the heat releasing boiler being at rest and releasing heat obtained during the heat releasing boiler having been in combustion,
a boiler increase determiner configured to determine whether or not a load factor, at which the heat releasing boiler resumes combustion and other boilers in combustion continue combustion, such that a first total amount of steam supplied by the heat releasing boiler after resumption of combustion and the other boilers in combustion is the same as a second total amount of steam having been supplied by the other boilers in combustion prior to the resumption of combustion of the heat releasing boiler, is higher than a predetermined load factor value, and
an output controller configured to cause the heat releasing boiler to resume combustion when the determiner determines that the heat releasing boiler exists among the plurality of boilers even if the other boilers in combustion maintain a margin in excess of reserve power corresponding to a varied steam flow which allows the other boilers to briefly increase an output of steam in response to a sudden load variation and the boiler increase determiner determines that the load factor is higher than the predetermined load factor value,
wherein the predetermined load factor value of each of the plurality of boilers is configured to fall in a highly efficient zone corresponding to a range where each of the plurality of boilers combusts efficiently, and to be a predetermined amount higher than a boiler number decreasing load factor which is used as a stop reference threshold according to which the controller determines whether to stop each of the plurality of boilers.

2. The boiler system according to claim 1 , wherein
the determiner for determining a heat releasing boiler determines that a combustion stopped boiler is the heat releasing boiler when an internal pressure of the combustion stopped boiler is higher than a predetermined pressure.

3. The boiler system according to claim 1 , wherein
the determiner for determining a heat releasing boiler determines that a combustion stopped boiler is the heat releasing boiler when a period of elapsed time during which an internal pressure of the combustion stopped boiler becomes lower than a predetermined pressure is shorter than a first amount of time.

4. The boiler system according to claim 1 , wherein
the determiner for determining a heat releasing boiler determines that a combustion stopped boiler is the heat releasing boiler when a body temperature or a water temperature of the combustion stopped boiler is higher than a predetermined temperature.

5. The boiler system according to claim 1 , wherein
the determiner for determining a heat releasing boiler determines that a combustion stopped boiler is the heat releasing boiler when a period of elapsed time during which the combustion stopped boiler has stopped combustion is shorter than a second amount of time.

Assignees

• Miura Kogyo Kk

Inventors

• Yamada Kazuya
• Namoto Tetsuji
• Saimi Hidetomo

Classifications

• F22B35/008 Primary

  Control systems for two or more steam generators (automatic water-feed control for a number of steam boilers designed for different ranges of temperature and pressure F22D5/36) · CPC title

• F22B35/00 Primary

  Control systems for steam boilers (for regulating feed-water supply F22D5/00; for controlling superheat temperature F22G5/00) · CPC title