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大型高压泵列车英文文献和翻译

时间:2018-04-13 15:54来源:毕业论文
Abstract There is clear trend for high-pressure trains of a larger size. For a given plant size it reduces the number of trains with the corresponding savings in installation costs. Furthermore, fewer, larger Irains generally mean less capit

Abstract There is clear trend for high-pressure trains of a larger size. For a given plant size it reduces the number of  trains with the corresponding savings in installation  costs. Furthermore, fewer, larger Irains generally mean less capital than more,  smaller trains. Larger units have,  inherently, higher efficiency. There  is a preference amongst plant designers and operators for la'ains  capable of operating reliably without pressure lubrication. Today  this  limits the train size to, approximately,  10,000m3/d,  considering  a  40-45%  conversion  rate.  Reliability,  availability,  dependability  are paramount.  Metallurgy  with  proven  track  record,  adequate material  combination,  reasonable  cost  and  ease  of processing is the key  to the success of  the installation. 21094
Keywords."  High-pressure pump; Alloy 885; Materials; RO train
I. Description
In  an  analogy  between  a  reverse  osmosis
plant and  the human body we  could  say that  the
membranes are  the  lungs  of the  system and  that
the feed pumps are the heart.
The main feed pumps, also known as the high-
pressure  trains,  are,  undoubtedly,  one  of  the
critical  components of the  plant.  As  such,  every
effort should be made to ensure this equipment is
most reliable, dependable and efficient. This brief
paper  focuses on  trains  of mid  to  large  size,  i.e.
trains for production of 2,500 mVd and larger.
The  high-pressure  train  on  today's  plants
typically consists of a high-pressure pump, driven
by an asynchronous electric motor, and an energy
recovery turbine  (ERT). The pump  increases the
feed  water  pressure  to  that  required  by  the membranes;  the  brine,  rejected  at high  pressure,
is  past  through  the  ERT,  which  recovers  that
energy.  The  electric  motor  provides  the  net
power.
The  most  common  configuration  is  that  in
which  the  electric  motor,  featuring  a  double
extended  shaft;  is placed  between  the  pump  and
the ERT,  three separate elements --  pump, motor
and turbine,  for much improved reliability, avail-
ability and maintainability.
2. Equipment configuration
On  seawater plants,  the high-pressure pump  is
of  the  centrifugal  type,  horizontal  configuration
and with multiple stages. The pump  casing could
either be  axially,  also  referred to  as horizontally,
split  or  radially  split  of the  segmental  ring  type.
It  is  not  the  intention  of  this  paper  to  compare
both  designs,  however,  an  analysis  of  the  in-
stallations yields the following results (Table  1).
Table 1
High-pressure  pump -  construction
Train size,  Segmental, Axially  Number  of
m3/d  radially  (horizontally)  trains
split, %  split, %  considered
2,500-4,000  67  33  90
4,000-5,500  32  68  75
Greater  than  7  93  130
5,500
In  the  smaller  segment,  2,500-4,000,  the
trend  is to  install  segmental  radially split pumps. 大型高压泵列车英文文献和翻译:http://www.youerw.com/fanyi/lunwen_13158.html
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