RU2399396C1 - Method of domestic and fire water system and unit for implementation thereof - Google Patents

Abstract

FIELD: medicine, fire fighting equipment.

SUBSTANCE: invention can be applied in integrated domestic and fire water systems. A domestic and fire water system control unit used to implement a method comprises a controlled electric pump, consisting of an alternating current motor and a frequency transducer, and a pressure switch. The switch is connected to the first input of a control unit. The second input of the unit is designed to be connected to external fire fighting mode activation instruction sources, e.g., to a fire detector, fire push buttons arranged near fire cocks. The unit is connected by an output to the transducer and manipulates the pump rotating frequency to keep the preset pressure. By the input command, the kept pressure increases between the input values H₁ to H₂. A complementary pump with its uncontrolled electric drive connected to an auxiliary output of the unit, is activated if switched pressure does not reach the preset pressure that provides higher reliability of the system, capital and maintenance saving to prevent water supply and ensure standard pressures in all operation modes.

EFFECT: there is offered the method of domestic and fire water system control.

4 cl, 1 dwg

Description

Technical field

The invention relates to combined drinking water supply systems and internal fire extinguishing of buildings and can be used in new construction and in the modernization of existing water supply systems.

State of the art

Systems combining the functions of domestic and drinking water supply and internal fire extinguishing of buildings are known and widely used in accordance with building codes and rules (see, for example, SNiP 2.04.01-85. Internal water supply and sewage of buildings).

Such systems contain a domestic drinking pump and a fire pump, which are connected to the combined piping for household drinking water and internal fire extinguishing by the outlet pipes. The household-drinking pump is designed to increase the pressure available in the city water supply to the pressure required for comfortable water supply at the dictating point of the building, and the fire pump is used to obtain a higher pressure that provides the SNiP standard 2.04.02-84, according to which the pressure on fire on the roof of the building should be at least 10 m high Both pumps have an uncontrolled drive, and the system is controlled by the fact that the domestic and drinking pump works constantly, and the fire pump is switched on from fire alarm sensors or from buttons installed near fire hydrants on the water supply floors, only in fire fighting mode.

As a result of long-term operation of the above-described systems, it turned out that they are not reliable due to the fact that the fire pump has been put out of operation most of the time (that is, it is in the “cold reserve” mode) and should start from an idle state (in some cases, preliminary opening of the valve) in case of fire. Organizational measures (including periodic testing of fire pumps) complicate the operation, but do not fundamentally eliminate this drawback and are often not performed by maintenance personnel.

Known technical solution aimed at eliminating the above drawback of existing water supply systems of buildings [patent RU 2106165]. A method of controlling a system improved according to this solution is that the drinking and fire pumps are equipped with an adjustable drive with feedback sensors that control the pressure (pressure) in the pipeline and are used both in the drinking and drinking mode fire water supply. At the same time, the pressure is measured by the indicated sensors, the pressure is set and maintained at the same level regardless of the mode (drinking water supply or fire fighting) and the amount of water intake by adjusting the speed of the pumps.

In the water supply system, controlled according to the described prototype method, the pumps that provide water for fire extinguishing, are constantly working, and therefore there is no need to start them in case of fire.

However, the prototype has the disadvantages consisting in the fact that:

- equipping both fire and household drinking pumps with an adjustable drive requires significant capital costs;

- to comply with the SNiP 2.04.02-84 standard, which requires that the pressure on the roof of the building is not less than 10 m.w. during the fire fighting process, the overpressure must be constantly maintained in the water supply pipeline;

- most of the time, all pumps (and in particular a more powerful fire pump) operate in a low flow rate (relative to the nominal value) and, therefore, with low efficiency.

These disadvantages, the elimination of which is the objective of the present invention, lead to increased capital costs, reduced reliability of water supply due to excess pressure maintained in the pipeline, and unproductive losses of electricity to the pump drive.

SUMMARY OF THE INVENTION

The technical result of the invention is to increase the reliability of the system, saving capital and operating costs without losing the comfort of water supply and ensuring regulatory pressures in all operating modes.

The subject of the invention is a method for controlling a water supply system in drinking water supply and internal fire fighting modes, which consists in setting and measuring the pressure in the building inlet pipe in both modes, comparing the measured pressure with the set pressure, and adjusting the rotation speed of at least one pump pressure maintenance systems, increase the set pressure when the system is put into internal fire extinguishing mode and start at least one additional pump with uncontrolled electrical water, if the measured pressure does not reach the set.

Clarifications and development of the method relate to special cases of its implementation and consist in the fact that:

- the pressure level in the drinking water supply mode is set based on the comfort requirements of the drinking water supply at the dictating point of the pipeline, and in the fire extinguishing mode - equal to the maximum permissible standard for drinking water and fire water systems;

- the pump speed is limited to a value corresponding to a frequency of 60 Hz of the supply voltage.

This allows you to optimize the operational characteristics of the modernized water supply systems without replacing the motors and pumps installed in them.

The subject of the invention is also a device for implementing the method, comprising a main pump with an adjustable electric drive, an additional pump with an unregulated electric drive, connected by outputs to a water supply pipe in which a pressure sensor is installed, and a control unit, the first input of which is connected to a pressure sensor, and the second is intended for connecting the command to the fire extinguishing mode to the sources, while the control unit is connected by the first output to the controlled electric drive of the main pump, second output - to unregulated motor drive additional pump and configured to regulate the rotational speed of the main pump to maintain the pressure, increasing the pressure maintained in the translation device extinguishing mode and with the possibility of including an additional pump if the measured sensor pressure reaches a predetermined.

Brief Description of the Drawings

The drawing shows a block diagram of a device that illustrates the implementation of the proposed method, taking into account its developments.

The block diagram contains the main pump 1 with an adjustable electric drive, consisting of an AC motor 2 and a frequency converter 3, and an additional pump 4 with an unregulated electric drive 5. Pumps 1 and 4 are connected by outputs (via check valves) to the water supply pipe 6, in which pressure sensor 7. The device has a control unit 8, the sensor 7 is connected to the first input 9 of it. The second input 10 of block 8 is used to connect the command to put the unit into fire extinguishing mode, for example, a fire alarm sensor, fire extinguishing buttons located near fire hydrants (PC) . Block 8 is connected by the output 11 to the converter 3. At the inputs 12 and 13 of block 8, the values of H ₁ and H ₂ of the pressure settings are set.

Block 8 is made with the possibility of regulating the speed of the pump 1 to maintain the pressure at the level of H ₁ set at the input 12, and with the possibility of increasing the pressure in the pipeline 6 to the level of H ₂ set at the input 13, when the unit is put into fire extinguishing mode by command, received at input 10 of block 8.

In addition, the drawing shows dead ends 15 with water taps and fire hydrants on the floors of the building, supplied with water through the pipeline 6. The drawing shows a single-line building water supply scheme used for buildings up to 12 floors, but the proposed solution can be effectively applied in case of more high buildings with a two-line scheme of drinking water and fire water supply.

Carrying out the proposed method, the device in the drawing works as follows.

Water from the city water supply through the supply pipe 16 to the suction nozzles of the pumps 1 and 4. In the absence of a fire extinguishing command, unit 8 compares the pressure measured by the sensor 7 with the pressure set at input 12 of the pressure H ₁ and, acting on the output 11 of the converter 3, regulates the frequency of rotation of the engine 2 and pump 1 to maintain the pressure in the pipeline 6 at the level of H ₁ . The value of H ₁ is chosen so as to ensure that the requirements of SNiP 2.04.01-85 for the comfort of water supply at the dictating point of the system are met when the pressure in the city water supply and all possible fluctuations in the water intake for household and drinking needs change. For example, in the case of a 12-story building, the required pressure value, set in the form of the setpoint N ₁ , is 46 m.st.

After the input to the input 10 of block 8 of the command to put the system into fire extinguishing mode, block 8 proceeds to regulate the speed of engine 2 to maintain the pressure in the pipeline 6 set at the input 13 of block 8 with the setpoint H ₂ . The setting value of H ₂ is selected so as to provide a pressure of at least 10 m.st. on the roof of the building, required by SNiP 2.04.02-84 (for example, in the case of a 12-story building, the setpoint N ₂ is 56-60 m high).

The calculations showed that the household drinking pump units installed in most current water supply systems are able, without replacing and without exceeding the rated parameters of electric motors and pumps, to maintain the required pressure in both modes if the output frequency of the converter 3 is controlled within zero to 60 Hz. At the same time, a certain decrease in reliability due to a short-term (only in the fire extinguishing mode) increase in the frequency of the voltage supplying the electric motor to 60 Hz (instead of the nominal ones for the electric motor of 50 Hz) is excessively compensated by the increase in reliability due to the use of a continuously functioning and, therefore, located in constant readiness of pumping equipment.

For those cases when the power of the main pump is not enough to create the required pressure, an additional pump 4 is provided (usually available in existing water supply systems) without the need to equip it with an adjustable drive. Block 8 includes an unregulated electric drive 5 of pump 4, if the pressure measured by the sensor 7 does not reach the corresponding set point for some time.

Comparison of the proposed solution with the prototype shows the following.

In the prototype, the common function of drinking water and fire water supply is assigned to the fire and drinking water pumps together, each of which must be equipped with an adjustable electric drive that automatically maintains a fixed pressure at the inlet to the combined pipeline for drinking water and fire water, regardless of the mode and size of the water intake (including regardless of the selection of water for fire fighting). Since the fixed pressure must be sufficient for fire fighting, the pressure in the pipeline 4 is constantly maintained, which is excessive for drinking water and worsens its reliability and comfort.

The nominal flow rate of the fire pump installed in the existing system and the power of its electric motor, as a rule, exceed the corresponding parameters of the drinking water pump installed in the same system and are also excessive for drinking water. All the more redundant for this function is the combined use of a fire pump and a household-drinking pump, the equipping of which with variable speed drives increases capital costs.

The proposed solution allows, having equipped one pump with a controlled electric drive, it can be used as a domestic drinking and firefighter, and when modernizing existing systems according to the proposed technical solution, it becomes possible to use, as such a pump, combining two functions, available in the existing household drinking system (and not a fireman) pump. In this case (unlike the prototype), the pump is operated in the design mode for flow and power, which provides the proposed installation with a higher average daily efficiency and corresponding energy savings.

The above confirms the receipt of the technical result of the invention in the form of increasing reliability, saving capital and operating costs without losing the comfort of water supply and the ability to provide current standards for pressure in the pipeline of the water supply system under all operating conditions.

Claims (4)

1. The method of controlling the water supply system in the drinking water supply and internal fire fighting modes, which consists in setting and measuring the pressure in the building inlet pipe in both modes, comparing the measured pressure with the set pressure, and adjusting the rotation speed of at least one system pump to maintain the pressure, increase the set pressure when the system is put into internal fire extinguishing mode and start at least one additional pump with an uncontrolled electric drive, if the measured pressure is not reaches a predetermined. 2. The method according to claim 1, characterized in that in the drinking water supply mode, the pressure is set based on the comfort requirements of the drinking water supply at the dictating point of the pipeline, and in the fire fighting mode, equal to the maximum allowable standard for drinking and fire water systems water supply. 3. The method according to claim 1 or 2, characterized in that the pump speed is limited to a value corresponding to a frequency of 60 Hz of the supply voltage. 4. The device for implementing the method according to claim 1, comprising a main pump with an adjustable electric drive, an additional pump with an unregulated electric drive, connected by outputs to a water supply pipe in which a pressure sensor is installed, and a control unit, the first input of which is connected to the pressure sensor, and the second it is intended for connection to the sources of the command to transfer to fire extinguishing mode, while the control unit is connected with the first output to the controlled electric drive of the main pump, and the second output to unregulated the electric drive of the additional pump and is configured to control the speed of the main pump to maintain the pressure, increase the supported pressure when the device is in fire extinguishing mode, and to turn on the additional pump if the pressure measured by the sensor does not reach the set value.

Images