Feed water system and thermal capacity of the introduction

The heat pump water system is mainly to deal with the heat generated by the pump at work, and the allocation of capacity, the purpose is to protect the feed pump from damage, the following is about the feed water pump thermal system and capacity . (1) minimum flow system After the high-pressure feed pump starts (or in operation), the outlet valve is not open (or closed), most of the work done by the prime mover is converted into heat energy, and the pump inlet Feed water temperature will rise, such as the temperature exceeds the deaerator water tank saturated vapor pressure allows the temperature, it is necessary to produce vaporization, in order to avoid this phenomenon damage to the feed pump, feed pump outlet valve leads to a part of the flow Water, in order to take away the heat generated by the prime mover so that the feed pump does not vaporize at low flow rates. Lead to the part of the flow that the so-called pump minimum flow (or recirculation flow). The recirculation system including the minimum flow valve is called the minimum flow system. The minimum flow range is determined by calculation and in combination with the test. Domestic and foreign information shows, and hydraulic, NPSHr, speed, water temperature, operating clearance and structure design. The general minimum flow rate is 20% ~ 30% of the pump design point flow. For supercritical units (above 600MW), the minimum flow rate of the feed water pump is continuously adjusted instead of the two-point switch, so as to avoid large fluctuations in the system when the minimum flow rate is running. Practice has proved that the minimum flow valve to determine the parameters and system layout, related to the safe and stable operation of the pump. (2) Warm pump system From theory and design point of view, the correct operating procedure is that the high pressure boiler feed pump should be warm pump before start-up, especially for the pneumatic feed pump group which should be used for low speed crank before starting, It is particularly important to avoid jamming and grinding as a result of thermal deformation in the pump body where hot water enters the cold state and thereby damaging parts of the pump. Of course, in an emergency, too late to start the pump that is not entirely impossible pump. From the experience of pneumatic pumps used by many power plants in our country, there are many cases of jamming and grinding in the segmented pump core without heating pump, and it is forced to execute the start-up procedure of directing the small steam engine. Internal pump is a volute type feed pump, to adapt to low-speed crankshaft and cold start features much better. The supercritical unit uses the inner pump to axially split the warm pump system of the volute-type high-pressure feed water pump. The system is simple and easy to operate (Figure 1-15). The current domestic subcritical unit of the pump system is also changed to this method. (3) high controllability of the pump group Large-capacity units, the controllability of the water supply pump group is getting higher and higher. In addition to the normal temperature, pressure and flow rate to be monitored, the vibration (including shaft vibration, axial force, speed, noise and failure) should be monitored and input into the computer for analysis. To facilitate the analysis of failure, to ensure the safe and reliable operation of the pump group to meet the requirements of the unit full of hair growth, (4) the configuration of the pump capacity of supercritical units, at home and abroad are configured in two ways: a general unit The configuration of the thermal power unit is 2 × 50% pneumatic pump group + 1 × 30% standby starting electric pump group, there are 2 × 50% pneumatic pump group + 1 × 30% starting electric pump group. Use, and then as a backup pump, so that electric pump head can be greatly reduced, with the configuration of the motor, gearbox (gearbox or fluid coupling) capacity can also be reduced, thus reducing the project cost.Currently, foreign Large supercritical units have adopted lx100% Pneumatic Pumps + 1x30% Starter Pumps and operate stably on a million-kilowatt-class unit, assuming a l00% capacity high-pressure feed pump must be safe and reliable. China Construction Water Show Guangzhou Central World Expo Industry leaders Pump manufacturers ranked Industrial Internet (Xiamen) Technology Co., Ltd. Asia Pump Network Editor: He Daohui (QQ / WeChat:) http://beng.liuti.cn/ (Service Hotline: 400 -6030-811)

1. Application:For LED Frame
2. Dimension: Customized dimension, OEM & ODM
3.Material: A6063, A6061, A3003 and other series alu alloy        
4.Suface treatment: Anodizing, polishing, turning ,power coating, mill finish etc
5.Equipment: CNC ,extruding machine, cold drawn machine, heating oven, straightening machine, cutting machine  

OD

OD Tolerance

ID

Tolerance

Roundness

Straightness

Circular  

 run-out

φ16-20

±0.02

±0.02

0.01↓

0.015↓

0.05↓

φ20-30

±0.02

±0.02

0.01↓

0.015↓

0.05↓

φ30-50

±0.05

±0.05

0.02↓

0.020↓

0.08↓

φ50-80

±0.15

±0.10

0.05↓

0.025↓

0.10↓


6. STANDARD PACKING:Wooden case/carton

7. Trade Terms
1. Payment: 30% T/T in advance, 70% balance pay before delivery.  L/C at sight.
2. Delivery time: 20 days after deposit receiverd. If opening mould, plus 7-10 days.
3. Trade Term can be chosen depending on your requirements.
4. FOB Port: Shanghai
Contact Us
If you want more info.about the aluminum tubes/profiles, please feel free to contact us.
1. Attn: Karina Gu  
2. Mobile: +86-18961469527
3. Tel: +86-519-88761254

Aluminum Profile For LED Frame

Aluminum Profile For Led Frame,Led Aluminium Profile,Led Extrusion Profiles,Led Aluminium Extrusion Profiles

Changzhou YiFei Machinery Co., Ltd. , https://www.yifeialu.com