Pump is a ship widely used hydraulic
machinery, it consists of a prime mover drive, and the mechanical energy into
fluid pressure energy, potential energy and kinetic energy. Pump medium liquid
is water and oil.
In order to pump water, fresh water, fuel,
oil and other liquids, the need for a certain amount and different type of
pumps. Generally in the engine room must be set bilge pump, fuel pump and oil
pump, boiler feed pump, cooling pump, ballast pump, sanitary pump and other
major pumps.
In the marine machinery and equipment,
marine pump is a large number, variety and important ship matching products. It
is widely used in ship power system, fire protection system, cooling system,
pressure loading system, stripping system, life security services and other
special system, but also be equipped in certain auxiliary devices. In recent
years, the domestic ship large, ship type diversification, the trend of the
whole ship automation is increasingly obvious.
In general, the number of various types,
different uses pump total number accounted for 20-30%, the total power of
ship's equipment 5-15%. In addition, marine pumps have been widely used in
marine engineering equipment, docks, port terminals, etc.
Summary
Pump is to increase the liquid and liquid
material pressure or flow. Deliver liquid to a higher location, distance, higher
pressure must use the pump, the pump can also be used to produce high pressure
liquid for hydraulic transmission. Motor driven by electric or other.according
to the working principle can divided into vane pump, (such as centrifugal pump,
mixed flow pump, axial flow pump, vortex pump), displacement pump (reciprocating
pump, rotary pump) and other types of pumps, (such as jet pump, electromagnetic
pump, etc.); according to the structure is divided into vertical pump
horizontal pump, self- priming pump and non self- priming pump; according to
use can be divided into dynamic pumps (such as boiler pump, condensate pump,
circulating pump, fuel pump, lubricating oil pump and cooling water pump, etc.)
and ship system pump( ballast pump, bilge pump, water pump, sanitary pump, fire
pump, cargo oil pump, vacuum pump, mud pump and fishing pump, etc.) Flow rate and
head are the two main parameters of pump.
Marine pump features: requirements pump when
ship sway and incline, not due to inhalation of level fluctuation have
cavitation occurs; in order to reduce the occupied area of pump and convenient
maintenance, general use vertical structure; through flow components are made
of bronze, made of stainless steel and other materials, to as much as possible
to reduce corrosion.
classification
Marine pump has a very wide range of
applications in ships, according to different purposes, can be divided into:
1, marine power plant pump
With fuel pump, lubricating oil pump, seawater pump, fresh water pump, steering gear or other hydraulic deck machinery
hydraulic pump, boiler device water feed pump, cooling water pump, sea water
desalination device of water pump and condensate pump.
Bilge pump, ballast pumps, fire pumps,
daily fresh water pump, daily water pump, hot water circulation, and doubles as
a pressure load, fire protection, bilge general pump.
Some special purpose ship, also has special
operation requirements and special pump provided, such as oil tanker cargo oil
pump, hopper dredger mud pump, salvage ship salvage pump, spray propulsion ship
water boost pump, no net fishingship fishing pump.
According to the working principle, the
marine pump mainly has following categories:
1, volume type pump
Positive displacement pump is by the
movement of working parts caused by volume of work periodically changes and
liquid smoke platoon. When working volume increases, and the pressure is dropped
inhalation liquid, when working volume decreases and pressure discharging
liquid, by crushing the pressure of liquid can increase. According to the way
of moving parts, it can be divided into reciprocating pump and rotary pump. The
former has a piston pump and cylinder pump, the latter has a gear pump, screw
pump, vane pump, etc..
2, vane pump
Impeller pump mainly by increasing the
liquid kinetic energy to increase the liquid energy. It relies on the impeller
to drive liquid for high-speed rotary motion, continuous production of suction
and discharge, the mechanical energy can be transferred to the liquid delivery,
so that the liquid pressure can be increased, and to achieve conveying liquid.
According to different characteristics of pump impeller and flow channel, it
can be divided into centrifugal pump and vortex pump.
3, jet pump
Jet pump is a working fluid with a certain
pressure to produce high speed jet injection fluid in the nozzle, and then
through the momentum exchange, the energy of injection fluid is increased.
According to different working fluid, it can be divided into water jet pump, steam
ejector and air ejector.
Pump in addition to classification
according to the working principle, can also according to position of pump
shaft is divided into horizontal pump and vertical pump; according to number of
suction inlet is divided into single suction pump and double suction pump;
divided by prime mover driven into electric pump, steam pump and diesel pumps,
marine pump most electric pump and emergency fire pump is directly driven by a
diesel engine, cargo oil pump often consists of a steam turbine drive.
Performance
parameter
In order to explain the basic working
performance of pump , convenient select and compare the performance of pump ,
usually expressed in the following parameters.
1, displacement
Pump displacement refers to the amount of liquid
discharged or transported by pump in the unit time, often expressed in volume
displacement, and its unit is m3/h.
2, pressure head
Pump pressure head is used to overcome the
resistance of suction and exhaust pipe and the suction and discharge of liquid
level of the pressure difference, pressure liquid to a certain height of the
energy. the pressure difference between the suction and discharge ports can be
approximately measured by the pressure difference between suction and discharge
ports. It is expressed as a unit of liquid in the flow through pump the
pressure can be obtained.
3, power and efficiency
Power is usually expressed as power and
output power is expressed in kilowatts. Pump efficiency is the ratio of the
output power to the shaft power, and it is the index of pump work economy.
4, speed
Refers to the pump shaft rotation per
minute, unit is R / min. Reciprocating speed can also be used in the double
stroke piston number per minute completed said.
没有评论:
发表评论