Computerized systems of increasing pressure of АSPD
ASPD types :
Problem and solution
Usually during the analysis of system’s parameters because of service wear of the equipment and supply service lines appear the problem when the pumps operational resources do not coincide with the rated technical characteristics. This can be solved by two ways: either through regular expensive and difficult real tests of the equipment, or with the help of constant feed back of the each unit with the governing centre. According to already existing characteristics of the each pump the compound characteristic “head-discharge-power” is build. Of course the second variant is more preferable. Though it requires some first big investments, because of its effectiveness the difference in expenses is compensated in the first 2 – 3 years. This is confirmed by successful experience of regional municipals, who put into practice automatic systems of pressure increasing.
АSPD manufactured in town Livny can be effectively be used in organizations of water supply in town and according to modification provide regular water supply either for the separate houses or for the residential complex consisting of 100-500 flats.
With the help of computerized systems of increasing pressure one can put into practice the cascade water supply according to the intensiveness of water intake in water supply systems ( also gradually will consume electric power supply).
Nowadays the typical sizes are forming according to the consumer’s requirements. The enterprise have a possibility to supply ion markets АSPD control cabinets of its own design, intended to governing of 2-5 pump units either in automatic regime or by hand with power diapason 0,55-7,5 kW with cascade and frequent regulation.
Besides the traditional protective functions for motor, keeping the rated parameters and etc. provide a possibility for operating data transmission and the emergency situation at mobile phones. There are also some eccentric technical solutions with the help of which the governing cabinets manufactured by OJSC “HMS Pumps” have the benefits in comparison with the products manufactured by other enterprises.
Assignment and Design
Automatic systems of increasing the pressure of (ASPD) are intended for industrial, municipal power supply, heating, cooling and fire - extinguishing systems and etc. The main condition for its work is that pumping liquid in its chemical and physical compound should not be aggressive for the pump parts and should not include abrasive and long-fibrous particles.АSPD can be used for other purpose if their parameters and version are satisfier the operating and safety conditions.
Computerized systems of increasing the pressure consists of two main parts :
- Line consisting of 2-5 pump units of CNSl types installed on common frame and connected parallel between the intake and exhaust manifolds. In each gauge the licked device is mounted which allow if necessary to disconnect and remove any pump from its line for repair or replacement, and also nonreturn valve, vibration dampers, and vibration support ;
- Governing automatic block which can protect the devices from current increase and “dry” functioning.
АSPD can operate in automatic regime and in the manual mode. For the uniform usage of recourses the change of the consecutive switching of pumps is provided. The system keeps the rated pressure diapason in the initial manifold through switching on/ off the necessary amount of pumps while decrease/increase the rated pressure according to the signal in the pressure-sensitive relay.
With the help of computerized systems of increase of pressure one can make a cascade water supply regulating according to the intensiveness of water-intake in the system of water supply (also gradually will consume electric power supply).
The computerized system of increase the pressure provide the following functions:
- keeping the rated pressure and temperatures;
- automatic closing and shut down the pumps according to the rated minimum and maximum pressure and temperature;
- turning on the reserve pump in an emergency;
- automatic interchanging of pumps;
- start of pumps in a mode of manual control;
- protection against overflow of a current;
- protection against overflow of temperature of the winding motor;
- protection against “dry” functioning;
- self-starting after the difference of voltage.
The choice of system for pressure increase
For the choice of system for pressure increase is recommended to use "The questionnaire for computerized systems of increasing the pressure of АSPD"
Key parameters for the choice of system of pressure increase are:
- Minimum and maximum water discharge by the consumer (Qmin, Qmax)
- Minimum and maximum head on the suction manifold (Н вх min, H вх max)
- Geodesic height from the pump equipment up to the consumers on the greatest removal on vertical (ДН)
- Residual head at the consumers who are of the great removal on vertical (Ноет)
- Head losses in water supply system (Нпотерь)
By Qmin и Qmax the amount of pumps in system of pressure increase and their productivity is defined. The minimum water discharge consumers is approximately equal to nominal capacity of one pump. Maximal discharge - summary capacity of all the pumps working in nominal conditions. всех насосов, работающих в номинальном режиме. If necessary the system of pressure increase can be completed by the reserve pump.
The head created by the system of the pressure increase should provide water pressure in the places of location the consumer not below 1-1,5 atm (Ноет) and is not higher 4-5 atm. In case of multistory buildings with the height exceeding 30m (approximately 10 floors) in order to avoid a situation when water will arrive under the pressure exceeding 4-5 atm to the consumers on the lower stores is necessary to provide installation of pressure reducers or install 2 systems of pressure increase for upper and lower stores. Generally pressure which the system should provide is defined by formula: НASPD = ДН + Ноет + Нпотерь - Нвх min.
Head losses in pipelines of buildings can be evaluated in 0,5 m for a floor with new pipes and in 1 m for a floor with old systems of pipes.
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