TDH: Tổng áp động lực
áp suất cần được tạo ra trong bơm, khi bơm theo tốc độ mong muốn.
TDH = Static Lift + Static Height + Friction Loss
where:
Static Lift is the height the water will rise before arriving at the pump (also known as the 'suction head').
Static Height is the maximum height reached by the pipe after the pump (also known as the 'discharge head').
Friction Loss is the head equivalent to the energy losses due to viscose drag of fluid flowing in the pipe (both on the suction and discharge sides of the pump). It is calculated via a formula or a chart, taking into account the pipe diameter and roughness and the fluid flow rate, density and viscosity.
Calculate your Total Dynamic Head (TDH) in three easy steps ==>>xin vào đây
To choose the right pumping system you need to first calculate your "Total Dynamic Head" (T.D.H). Total Head is the actual height to which water is to be pumped - from the water level at the source to the highest delivery point. Total Dynamic Head (T.D.H) takes into account the friction loss created by the movement of water through the delivery pipeline.
T.D.H. is the addition of
Static Lift + Static Height + Friction Loss.
Static Lift - is the height in metres from the low water level to the ground level where the Windmill or Solar Modules will be mounted.
Static Height - is the height in metres from where the Windmill or Solar Modules will be mounted to the highest point along the delivery pipeline.
Friction Loss - the resistance to water flow - is expressed as height in metres per kilometre of pipe.
Step 1: Determine Static Lift.
Using the diagrams below as a guide, measure the height from the low water level to ground level where the Windmill or Solar Modules will be mounted. This is usually done with a tape measure
My static lift is: Meters.
Step 2: Determine Static Height.
Using the diagrams below as a guide, measure the height from the ground level where the Windmill or Solar Modules will be mounted to the highest point along the delivery pipeline.
This measurement can be taken by
- Using an Altimeter
- Measuring the pressure in an existing (full) Pipeline (see Tech Note - Pressure, Head & Friction Loss)
- Using a sight level
- Reading the contours on a map.
My static height is Meters.
Step 3: Determine the Friction Loss.
The following tables list the Friction Loss for various types and size of pipe. Follow these few steps to determine the friction loss per 1000 Metres of Pipeline.
- Decide which system you plan to use. Is it a Windmill, or a Solar system - Fixed or Tracking Array?
- Decide what volume of water is required per day.
- Using a Litres per Day number that is larger than required, pick out the Friction Loss (Metres of head per every 1000 Metres of Pipeline) for your pipe size. If you don't have an existing pipe, select a pipe size that has a Friction Loss number less than 10. The smaller the Friction Loss number, the better it is.
- Enter your Friction Loss Number and the length of your pipeline in the boxes provided below the tables.
| Friction Loss for Rural "B" Imperial Polyethylene Pipe | |||||||||
| Litres per day | Litres per Second | Friction Loss Number (Metres per 1000 Metres of Pipeline) | |||||||
| Windmill | Solar Fixed Array | Solar Tracking Array | 1/2" | 3/4" | 1" | 1.1/4" | 1.1/2" | 2" | |
| 2160 | 1296 | 1728 | 0.06 | 34.0 | 4.9 | 1.2 | |||
| 2880 | 1728 | 2304 | 0.08 | 58.0 | 8.4 | 2.1 | |||
| 3600 | 2160 | 2880 | 0.10 | 84.0 | 12.0 | 3.2 | 1.0 | ||
| 7200 | 4320 | 5760 | 0.20 | 295.0 | 43.0 | 10.5 | 3.5 | 1.5 | |
| 10800 | 6480 | 8640 | 0.30 | 590.0 | 86.0 | 20.4 | 7.5 | 2.9 | |
| 14400 | 8640 | 11520 | 0.40 | 150.0 | 37.0 | 12.2 | 4.8 | 1.3 | |
| 18000 | 10800 | 14400 | 0.50 | 205.0 | 54.0 | 18.5 | 7.1 | 1.9 | |
| 21600 | 12960 | 17280 | 0.60 | 290.0 | 75.0 | 20.5 | 10.0 | 2.6 | |
| 25200 | 15120 | 20160 | 0.70 | 380.0 | 96.0 | 32.0 | 12.8 | 3.4 | |
| 28800 | 17280 | 23040 | 0.80 | 490.0 | 120.0 | 42.0 | 16.5 | 4.3 | |
| 32400 | 19440 | 25920 | 0.90 | 600.0 | 145.0 | 51.0 | 21.0 | 5.2 | |
| 36000 | 21600 | 28800 | 1.00 | 750.0 | 180.0 | 62.0 | 25.0 | 6.2 | |
| 43200 | 25920 | 34560 | 1.20 | 250.0 | 85.0 | 34.0 | 8.5 | ||
| 50400 | 30240 | 40320 | 1.40 | 340.0 | 115.0 | 44.0 | 11.5 | ||
| Friction Loss for Metric - Class PN 6.3 - Polyethylene Pipe | |||||||||
| Litres per day | Litres per Second | Friction Loss Number (Metres per 1000 Metres of Pipeline) | |||||||
| Windmill | Solar Fixed Array | Solar Tracking Array | 20mm | 25mm | 32mm | 40mm | 50mm | 63mm | |
| 2160 | 1296 | 1728 | 0.06 | 7.9 | 2.2 | 0.6 | |||
| 2880 | 1728 | 2304 | 0.08 | 13.5 | 3.7 | 1.1 | |||
| 3600 | 2160 | 2880 | 0.10 | 20.3 | 5.7 | 1.6 | 0.5 | ||
| 7200 | 4320 | 5760 | 0.20 | 73.5 | 20.4 | 5.7 | 1.9 | 0.6 | |
| 10800 | 6480 | 8640 | 0.30 | 155.7 | 43.3 | 12.2 | 4.1 | 1.4 | |
| 14400 | 8640 | 11520 | 0.40 | 73.8 | 20.7 | 6.9 | 2.3 | 0.7 | |
| 18000 | 10800 | 14400 | 0.50 | 111.6 | 31.3 | 10.5 | 3.5 | 1.0 | |
| 21600 | 12960 | 17280 | 0.60 | 156.4 | 43.9 | 14.7 | 4.9 | 1.4 | |
| 25200 | 15120 | 20160 | 0.70 | 208.1 | 58.4 | 19.5 | 6.6 | 1.8 | |
| 28800 | 17280 | 23040 | 0.80 | 266.4 | 74.8 | 25.0 | 8.4 | 2.2 | |
| 32400 | 19440 | 25920 | 0.90 | 331.4 | 93.0 | 31.1 | 10.5 | 2.7 | |
| 36000 | 21600 | 28800 | 1.00 | 402.8 | 113.1 | 37.7 | 12.7 | 3.3 | |
| 43200 | 25920 | 34560 | 1.20 | 158.5 | 52.9 | 17.8 | 4.5 | ||
| 50400 | 30240 | 40320 | 1.40 | 210.9 | 70.4 | 23.7 | 5.9 | ||
Enter your Friction Loss number here: Metres per 1000 Metres
Enter the length of your pipeline here: Kilometres
My Total Total Friction Loss is Meters
My Total Dynamic Head is Meters
You now know your Total Dynamic Head (T.D.H) and the volume you require per day. From these two numbers it is easy to determine the best system to suit your need. Fill out our Enquiry Hotline and we will send you a detailed quotation.
Công cụ tính TDH online khác: (bạn tải về bằng cách bấm chuột phải vào chương trình và chọn view selection source và save lại)
http://www.pumprite.com/pumprite/tdh.htm
SCCK.TK (wdmoore.com.au)
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