on my experience and consistent with approaches to design across the industry,
a typical design development process for a coal fired power plant incorporates
three distinct phases that result in the design being completed and
documentation issued for construction. These phases include:
project planning and analysis stage (sometimes referred to as the concept
stage) in which several options for a project development are investigated and
a preferred option recommended. This phase is characterised by a significant number of assumptions with
various levels of uncertainty associated with each one. This stage typically
represents less than 5% of the design effort and is normally carried out internally
by the project owner. At no stage in this project planning and analysis stage
is plant, equipment or even process or systems considered. At this stage a
power station is simply characterised
by its major inputs and outputs and assumptions about major parameters such as
heat rate (efficiency), maximum output, capacity factors, availability of fuel
and water supplies, capital and operating costs and likely power sale revenues.
These broad parameters are generally used to feed into a basic financial model
in order to confirm likely returns on investment and assist in option
Basic Design stage (sometimes referred to as a concept design or preliminary
design stage) in which the preferred option is reviewed, preliminary sizing
carried out, and assumptions (financial and technical) confirmed and retested
in the financial model and against business case parameters.
the Basic Design Phase it is commonly expected that major plant and equipment
is selected, key features of the design are investigated and process flow
diagrams prepared. The design at this stage provides sufficient information for
confirming key financial and technical assumptions and for conducting safety
reviews such as HAZOPs and HAZID workshops. The intention of this Basic Design
development is to lock down the design so that detailing can proceed with
confidence and minimal change. All key features of the design of each
discipline (Civil, Mechanical, Electrical etc) are established at this stage.
this phase the design is developed to the stage that key aspects of the project
are confirmed and risks around achievement of those parameters able to be
quantified. This stage typically represents 10% to 30% of the design effort and
in the power generation sector is normally carried out as the first part of the
responsibility of the EPC or D&C contractor. It can also be completed as
part of the EPCM role undertaken by a project or engineering Manager.
Detail Design Stage during which the design is fully detailed by technical
calculation, drawings, specifications, schedules and other documentation ready
for issue for construction. This stage typically represents the remaining 65%
to 85% of the design effort and like the Basic Design role is normally carried
out as part of the responsibility of the EPC or D&C contractor and can also
be completed as part of the EPCM role undertaken by a project or engineering
My opinion is supported by the case of Drbal,
Boston, Westra and Erickson, Power Plant Engineering, Springer, New York, 1996
我的观点由Drbal, Boston, Westra
and Erickson, Power Plant Engineering, Springer, New York, 1996
defines ‘design’ broadly, and as a process that includes how an engineer will
go about developing and achieving the desired result:
It is vital that the goals, objectives, and
constraints for each project be carefully defined in the planning and analysis
stage. Project planning and analysis encompasses those strategic elements of a
project that must be considered early in project development. Fuel supply
studies, system planning studies, siting evaluation, transmission planning
analyses environmental feasibility analyses, and economic and financial
feasibility analyses are integral to project planning and analysis for new,
power generation facilities.
Conceptual design engineering encompasses a broad
variety of activities. The conceptual design process consists of systematically
defining and evaluating the basic conditions and constraints applicable to a
specific [power] generating plant. Conceptual design engineering starts as part
of the project planning and analysis activities, and is increasingly required
in support of permitting and licensing activities.
Detailed design engineering includes determining
the technical requirements for all plant components. It involves consideration
of equipment sizing, reliability constraints, performance requirements, and codes and standards, all directed
toward requirements for successful specification, construction, and startup
(the emphasis is not in the original).
goes on to discuss ‘conceptual design’ further in these terms:
Conceptual design engineering is a systematic,
objective, investigative process in which the basic technical requirements,
operational characteristics, and constraints applicable to a specific power plant
system are evaluated and defined.
Conceptual design engineering provides the basis
for selecting design concepts and equipment, and defines the key design
features of the plant, functional systems and structure, system and equipment
design constraint, plant performance, and plant costs. Conceptual design
engineering lays the technical foundation for the follow-on detailed design
process, equipment procurement, construction, and operation of the new
text then develops this design characterization further, and defines 3 possible
levels of ‘conceptual design, being:
the first level as a very broad engineering
assessment for the project that generally supplies sufficiently accurate
information to support system planning studies, preliminary economic and
financial assessments, and plant siting evaluations. Level 1 design is usually done by the owner
and is part of the feasibility process for determining whether or not to
proceed with the investment;
the second level of ‘basic design’ provides
additional detail regarding site layout, plant performance and individual power
plant systems in support of, among other things, permitting and licensing
third level is very specific with regard to system and equipment design, and
allows for, among other things, equipment specification and purchase.
the approval of the use of specific codes and standards a requirement to be
finalised as part of a Basic Design stage or part of the Detailed Design Stage?
on my experience leading the Owners team for a number of Power Station
developments, it is my opinion that finalisation of the selection of codes and
standards is not required at the Basic Design stage of the design development
process. Codes and standards are used to confirm detailed design requirements
and calculation methodologies, specify suitable materials, specify final manufacturing
and construction methodologies, specify safe operating and control
requirements. Codes and standards are not required for the confirmation of
basic design parameters such as confirming key project financial assumptions
and technical parameters, development of general plant layout arrangements,
production of process flow diagrams, calculation of key process inputs or
equipment sizing, production of electrical single line diagrams or for the
development of fundamental control philosophies.
of these basic design tasks is carried out based on considerable engineering
knowledge and extensive understanding of process requirements but they are not
impacted by the selection of one code or standard over another. In my opinion the process of preparing a
Basic Design package does not require the specific definition of codes or
use of Chinese codes and standards for non-critical power station plant
generally accepted for the development of international power projects?
on my experience of recent Australian power station projects it is becoming
more common to have EPC contractors from around the world seeking approval to
provide various pieces of power station equipment and materials manufactured to
Chinese standards, particularly where that equipment or materials are being
utilised on non-critical areas of the plant.
Quality Assurance provisions are the basis upon which most owners, project
developers and engineers seek to protect the integrity of their project in
circumstances where Chinese codes and standards are utilised.
am aware that both lender’s engineers and
insurer’s engineers for international projects commonly look for
compliance with well-known and well utilised US or other International
standards for design and manufacturing compliance of Key Equipment such as
Boilers, Turbines, Generators, Condensing and Feedheating plant and Electrical
systems, this compliance is particularly sought in relation to high pressure
and high temperature components, high and medium voltage components, control
and safe operational requirements as well as fire prevention on and around
Chinese codes and standards at this point in time are not as commonly accepted
for large power projects outside China as say Japanese standards, they are
beginning to be used more often outside China and their gradual emergence is a
similar situation to the increasing use of Japanese standards for power station
design back in the 1980’s.
acceptance of Completion of Basic Design delayed unreasonably as part of a 2
stage design process and if so what impacts did the delay to the approval of a
Basic Design have?
on my discussion in relation to the characteristics of basic design and
detailed design above, and assuming that a two stage approach is agreed as it
appears to have been for this project, it is appropriate that the Contractor
and the Owner separate the two phases of design. Due to time constraints it can
be common for some initial detail design work to be commenced in parallel but
this is usually only undertaken to the extent that it can practically commence
and to the extent that the Contractor is willing to take the risk of having to
duplicate work if the basic design changes.
The ramifications of commencing Detail Design before Basic Design is
completed are that there will not be sufficient fundamental design information
available to complete the detail design, there may be rework of the detail
design required in order to meet changed fundamental design information and
there is a risk of entering into procurement arrangements for plant and
equipment that may change, resulting in rework or resupply of compliant plant
and equipment which in turn would have resulted in further delays to the
lack of fundamental design information from a Basic Design process can also
have flow on implications for multiple power plant systems. For example the
delayed decisions in relation to the Flue Gas system including the additional
space required prior to the Bag Filters in order to fit a potential FGD plant
later on, the requested upgrading of the ID Fan to cater for the potential
increased pressure drop through this FGD plant and a bypass around the Bag
Filters has implications for civil earth works, ductwork support structure,
boiler structural steel, boiler control system etc.
important example is the flow on impact that a delay to finalising the
structural steel for the Main Block can have on completion of the project.
Bridge Crane in the turbine hall (referred to in this project as the Main
Block) is designed to be used for lifting the major turbine and generator
equipment for installation, replacement and maintenance purposes. In
particular, the Bridge Crane is necessary to install the turbine and generator
onto the turbine foundations and that installation cannot commence until the
Bridge Crane is commissioned and available.
Bridge Crane itself cannot be installed until the columns on Grids A and B of
the Main Block are erected and the crane beams upon which the Bridge Crane
travels are installed on the columns. Accordingly, it is crucial to the
installation of the turbine and generator that the columns on Grids A and B are
erected before the erection of the bridge crane and the delivery of the turbine
and generator to the Site.
coal bunker/Deaerator bay contains a significant amount of equipment (including
condensing and feedheating plant, main steam pipes, all the major switchrooms,
the control room, the boiler bunkers and coal conveyors and feeders and much of
the HVAC equipment), that was the subject of a significant number of the DQs
including the DQs concerning the selection of codes and standards.
my opinion the delay to approval of Basic Design would have resulted in:
delayed development of the detailed construction design and issuing of drawings
with a specific delay resulting to critical path drawings such as Boiler and
Main Block structural steel;
delayed ability to finalise equipment lists and fabrication requirements
(including structural steel);
delay to finalisation of basic Heat and Mass balance and flow information
impacting on the finalisation of Boiler, Turbine and Generator and major
equipment design and manufacture.
flow on impact from the delay to Main Block structural steel design and
fabrication is a delay to the erection of columns for the coal bunker/deaerator
structure which in turn delays the erection of the Bridge Crane and the lifting
of the turbine and generator onto their foundations.