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STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES (gas-turbine or jet-propulsion plants F02; nuclear power plants, engine arrangements therein G21D)
Definition statement
This subclass/group covers:

All aspects of power plants using steam, vapour or special working fluids in a thermodynamic cycle. It covers also steam or vapour accumulators and power plants which are characterised by steam or heat accumulators, by the use of specific types of engines and by condensers and by the use of steam or condensate extracted from the power plant. Furthermore general lay-out, control and methods of operation of complete power plants and methods of converting heat or fluid energy into mechanical energy are covered.

Relationship between large subject matter areas

Specific elements forming a thermodynamic cycle like the steam or vapour generator (F22B), expander (F01D), condenser (F28B) and pump (F04) are the subject of other subclasses.

Documents related to constructional features of steam turbines, gas turbines, internal combustions piston engines, condensers and pumps can be found in F01D, F02C, F02B, F28B and F04B, F04C, F04D respectively.

References relevant to classification in this subclass
This subclass/group does not cover:
Nuclear power plants and engine arrangements therein
Internal-combustion piston engines
Gas turbine plants
Jet propulsion plants
Non-positive displacement machines or engines, like steam turbines
Refrigeration machines, plants and systems
Special rules of classification within this subclass

Attention is drawn to the definition of "steam" and "vapour". In cases where a specific entry for vapour is missing documents related to special vapours are classified in groups where only "steam" is explicitly mentioned.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
CHP
Combined Heat and Power, Cogeneration
Trigeneration
Combined production of heat, power and cold
HRSG
Heat Recovery Steam Generator
CCS
Carbon capture and storagecarbon capture and sequestration
Combined cycle
The exhaust of one heat engine is used as the heat source for another
FBC
Fluidized Bed Combustion
PFBC
Pressurised Fluidized Bed Combustion
APFBC
Advanced Pressurised Fluidized Bed Combustion
GFBCC
Gasification Fluidized Bed Combustion Combined cycle systems
CHIPPS
Combustion-based High Performance Power System
Steam accumulators (use of accumulators in steam engine plants F01K 3/00)
Definition statement
This subclass/group covers:

Steam or vapour accumulators acting as an energy storage device including:

  • accumulators for storing steam in a liquid, like varying pressure accumulators (e.g. Ruth's type);
  • accumulators for storing steam otherwise than in a liquid (e.g. pressure tanks);
  • charging and discharging devices of accumulators with steam;
  • safety and regulation means for accumulators;
  • other parts, details and accessories of accumulators.
Relationship between large subject matter areas

Group F01K 3/00 covers the use of accumulators in steam engine plants and not the accumulator per se.

References relevant to classification in this group
This subclass/group does not cover:
Use of accumulators in steam engine plants
Informative references
Attention is drawn to the following places, which may be of interest for search:
Methods of steam generation using heat evolved in a solution absorbing steam; Soda steam boilers
Charging or discharging of accumulators with steam
Multiple accumulators; Charging, discharging or regulating peculiar thereto
Steam circulation in multiple accumulators
Special rules of classification within this group

All vapour accumulators which use special vapour instead of water vapour also have to be classified in this group.

Synonyms and Keywords

In patent documents the following expressions/words "storage tank", "pressure tank", "vessel", "energy storage device" and "volume" are often used as synonyms.

Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein (regenerating exhaust steam F01K 19/00)
Definition statement
This subclass/group covers:

This group covers the use of steam/vapour accumulators, in general heat accumulators and intermediate steam/vapour heaters in power plant arrangements and in arrangements adapted for a specific use like for vehicle drive. Control of said devices is also covered.

Relationship between large subject matter areas

Vapour or heat accumulators are often used in relationship with steam or vapour regeneration which is treated in F01K 19/00

Constructional features of accumulators and the accumulators per se are classified in F01K 1/00

Methods of steam generation in general characterized by the form of heating method are classified in F22B 1/00

References relevant to classification in this group
This subclass/group does not cover:
Heat-transfer, heat-exchange or heat-storage materials
Regenerating exhaust steam
Informative references
Attention is drawn to the following places, which may be of interest for search:
Methods of steam generation characterized by the form of heating method
Heating, cooling or ventilating devices characterised by comprising regenerative heating or cooling means, e.g. heat accumulators
Heat storage plants or apparatus in general
Solar heat collectors having heat storage mass
Solar heat collectors with hot water storage
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Ruth's type steam accumulator
accumulator for storing steam in a liquid (variable pressure system)
Plants characterised by use of means for storing steam in an alkali to increase steam pressure, e.g. of Honigmann or Koenemann type
Definition statement
This subclass/group covers:

Storing steam based on thermo chemical energy storage and conversion. Absorbing and desorbing vapour into an alkali solution for discharging heat or producing cold taking into account pressure changes. Furthermore regenerative installations using absorption and desorption are also covered.

Relationship between large subject matter areas

Accumulators where steam is stored in a liquid are classified in F01K 1/04 in general.

References relevant to classification in this group
This subclass/group does not cover:
Thermodynamic cycles with an absorption fluid remaining at least partly in the liquid state, like Kalina cycles
Informative references
Attention is drawn to the following places, which may be of interest for search:
Accumulators using materials absorbing or liberating heat during crystallisation
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Accumulator of Honigmann type
Steam or vapour accumulator based on a process based on the vapour pressure depression of a concentrated solution or adsorbed vapour in comparison to the pure working fluid
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Last Modified: 10/11/2013