Plant operation method and plant operation control system

• US 5,467,265 A
• Filed: 02/10/1994
• Issued: 11/14/1995
• Est. Priority Date: 02/10/1993
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yoshioka, Masahiro, Nakahara, Masaji, Yamada, Akihiro, Shimoda, Makoto
• Primary Examiner(s): Ruggiero, Joseph
• Application Number:
  US08/194,520
• Time in Patent Office: 642 Days
• Field of Search: 364/130-194, 364/492-495, 395/11, 395/903, 395/904, 395/906, 395/907, 395/912, 395/914, 395/915, 395/919
• US Class Current: 700/49
• CPC Class Codes: F01K 13/02 Controlling, e.g. stopping or starting
• CPC Class Codes: F24D 10/00 District heating systems
• CPC Class Codes: F24D 12/02 having more than one heat source using heat pumps, in water central heating systems F24D3/18; in air central heating systems F24D5/12; in systems using heat storage masses F24D11/02
• CPC Class Codes: F24D 18/00 Small-scale combined heat and power [CHP] generation systems specially adapted for domestic heating, space heating or domestic hot-water supply
• CPC Class Codes: F24D 2101/30 Fuel cells
• CPC Class Codes: F24F 11/47 Responding to energy costs
• CPC Class Codes: F24H 2240/10 with fuel cells
• CPC Class Codes: F25D 2400/36 Visual displays
• CPC Class Codes: F25D 29/00 Arrangement or mounting of control or safety devices
• CPC Class Codes: G05B 13/00 Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion G05B19/00 takes precedence
• CPC Class Codes: H01M 8/04992 characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]
• CPC Class Codes: Y02B 30/17 District heating
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 80/14 District level solutions, i.e. local energy networks
• CPC Class Codes: Y02P 80/15 On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply
• CPC Class Codes: Y10S 706/907 Power plant

Abstract

A system for determining a cost effective and practical operation method for thermal source equipments includes a fundamental plan data storage unit, a fundamental plan generating unit for determining a fundamental operation plan of each equipment while minimizing an operation cost by linear programming, an operation knowledge storage unit for storing operation knowledge such as equipment performance characteristics and operation know-how, a fundamental plan evaluating unit for evaluating the fundamental plan, a modifying rule storage unit for storing modifying rules used for modifying the evaluated fundamental plan, and a fundamental plan modifying unit for modifying the fundamental plan in accordance with the modifying rules.

Claims

1. A plant operation system comprising:

input/output data storage means for storing input/output data of each equipment of a plant having a plurality of different type equipments;

fundamental operation plan generating means for generating a fundamental operation plan by reading said input/output data of each said equipment stored in said input/output data storage means and formulating said read input/output data, and by obtaining an input to each said equipment for each operation time period by using an optimal planning method, said input satisfying a target output of said plant;

rule storage means for storing knowledge rules regarding at least one of a life time and response characteristic of each said equipment;

means for evaluating said fundamental operation plan generated by said fundamental operation generating means by using said knowledge rules;

means for storing modifying rules for modifying a start/stop schedule and a load factor of each said equipment; and

means for modifying said fundamental operation plan by using said modifying rules.

2. A thermal source equipment operation determining method of determining a start/stop schedule and a running load factor of an energy supply plant having a plurality of different type thermal source equipments, comprising the steps of:

formulating a relationship between input and output of each said thermal source equipment and the restrictive conditions of upper and lower bounds of said input and output, and generating said start/stop schedule and said running load factor of each said thermal source equipment by a linear planning method, said start/stop schedule and said running load factor satisfying a target output of said plant and minimizing an energy consumption cost of each said thermal source equipment and/or an exhaust amount of toxic gas to air; and

modifying said start/stop schedule and said running load factor of each said thermal source equipment, by using knowledge rules regarding a life time and an output response characteristic of each said thermal source equipment.

3. A thermal source equipment operation determining method according to claim 2, wherein optimization of said start/stop schedule and said running load factor of each said thermal source equipment is evaluated by using said knowledge rules, in accordance with said evaluated results said restrictive conditions used for the execution of said linear planning method are changed, optimization calculation by said linear planning method is again performed, and said start/stop schedule and said running load factor of each said thermal source equipment are modified.

4. A thermal source equipment operation determining method according to claim 2, wherein as a method of evaluating optimization of said start/stop schedule and said running load factor of each said thermal source equipment, a stop time duration from when each said thermal source equipment is stopped and to when each said thermal source equipment is re-started, a load factor at the time of re-start, and an operation time duration from the time of re-start to the time of re-stop are compared with predetermined respective reference values, and in accordance with the comparison results with said reference values appropriateness of said start/stop schedule of each said thermal source equipment is judged.

5. A thermal source equipment operation determining method according to claim 2, wherein a steam absorption refrigerator is used as each said thermal source equipment, and as a method of evaluating optimization of and modifying said start/stop schedule and said running load factor of each said thermal source equipment, a dilution operation start time and a necessary dilution operation time duration of each said steam absorption refrigerator are detected, and said load factors of cooling and heating energy output equipments other than said equipment under said dilution operation are lowered so as to reduce a sum of output energies of said cooling and heating energy output equipments in the range equal to or less than the cooling energy generated by said equipment during said dilution operation.

6. A thermal source equipment operation determining method according to claim 2, wherein said output of each said thermal source equipment is forecast in accordance with past operation data.

7. A thermal source equipment operation determining method according to claim 6, wherein in forecasting said output of each said thermal source equipment, a neural network using said past operation data is used.

8. A thermal source equipment operation determining system of determining a start/stop schedule and a running load factor for a plurality of different type thermal source equipments, comprising:

means for formulating a relationship between input and output of each said thermal source equipment and the restrictive conditions of upper and lower bounds of said input or output, and generating said start/stop schedule and said running load factor of each said thermal source equipment by a linear planning method, said start/stop schedule and said running load factor minimizing an energy consumption cost of each said thermal source equipment;

operation rule storage means for storing knowledge rules regarding a life time and output response characteristic of each said thermal source equipment;

fundamental operation plan evaluating means for evaluating optimization of said fundamental operation plan by using said knowledge rules stored in said operation rule storage means;

modifying rule storage means for storing modifying rules for modifying said start/stop schedule and said running load factor of each said thermal source equipment in accordance with said fundamental operation plan evaluation results; and

means for modifying said fundamental operation plan in accordance with said modifying rules.

9. An energy supply plant operation control system including the thermal source equipment operation determining system set forth in claim 8, comprising means for displaying at least one of a set of said start/stop schedule and said running load factor of each said thermal source equipment, and a set of knowledge regarding a life time and output response characteristic of each said thermal source equipment.

10. An energy supply plant operation control system including the thermal source equipment operation determining system set forth in claim 8, comprising means for adding, deleting, or modifying knowledge regarding a life time and output response characteristic of each said thermal source equipment.

11. An energy supply plant operation control system including the thermal source equipment operation determining system set forth in claim 8, comprising means for displaying knowledge rules regarding a life time and output response characteristic of each said thermal source equipment on a display screen, and adding, deleting, or modifying said knowledge rules by designating with input means including a keyboard, a mouse, a light pen, and the like.

12. An energy supply plant operation control system including the thermal source equipment operation determining system set forth in claim 8, comprising means for displaying a relationship expression of input and output of each said thermal source equipment and a restrictive condition expression for upper and lower bounds of said input on a display screen, and adding, deleting, or modifying said relationship expression and said restrictive condition expression by designating with input means including a keyboard, a mouse, a light pen, and the like.

13. An energy supply plant operation control system including the thermal source equipment operation determining system set forth in claim 8, comprising means for displaying said modifying rules used for modifying said start/stop schedule and said running load factor of each said thermal source equipment generated by said linear planning method, on a display screen.

14. An energy supply plant operation control system including the thermal source equipment operation determining system set forth in claim 8, comprising means for displaying said modifying rules used for modifying said start/stop schedule and said running load factor of each said thermal source equipment generated by said linear planning method, on a display screen, and determining whether said modifying rules are to be modified or not by designating with input means including a keyboard, a mouse, a light pen, and the like.

15. An energy supply plant operation system comprising:

long term demand forecasting means for forecasting an energy demand up to a predetermined period;

operation plan generating means for determining a start/stop schedule and a running load factor of each thermal source equipment of said energy supply plant up to said predetermined period by using the forecast results by said long term demand forecasting means;

short term demand forecasting means for forecasting an energy demand during a short period shorter than said predetermined period; and

plan modifying and controlling means for modifying the whole or part of said start/stop schedule and said running load factor of each said thermal source equipment by using the forecast results by said short term demand forecasting means, and converting the modified results into a control signal for each said thermal source equipment,

wherein said operation plan generating means is the thermal source equipment operation determining system set forth in claim 8.

16. An operation method for a plant having a plurality of equipment of different types, comprising the steps of:

generating a fundamental operation plan by reading a past record of input data and output data for each said equipment from a database to formulate a relationship therebetween, and providing a constraint condition expression for determining an upper bound and a lower bound for an input or an output in the relationship formulated, to obtain, at every operation time period, an input or an output of each of said equipments making a value of a predetermined objective function maximum or minimum, while satisfying a target output of said plant; and

making rules of knowledge regarding lifetime and knowledge regarding a response characteristic of each said equipment, to modify at least one of the upper bound and the lower bound of the constraint condition expression on the basis of the rules, to obtain again an input or an output of each said equipment making a value of the predetermined objective function maximum or minimum.