RU2047842C1 - Method of determination of water discharge by objects of ring system of heat supply - Google Patents

Abstract

FIELD: heat supply, heat power engineering. SUBSTANCE: after measurement of summary water discharge and pressure losses in system with open shutting elements on all objects one of objects is disconnected in sequence. Then pressure losses in system are adjusted to pressure losses in system measured before disconnection of chosen object. Water discharge by this object is determined by difference of two successive values of discharge taken before and after disconnection of object. Measurements and adjustment are performed at heat supply station of system. Water discharge by objects which minimal discharge exceeds error of measurement of water discharge is measured then. EFFECT: increased reliability of method. 3 cl, 1 dwg

Description

 The invention relates to a technique for measuring the volume or mass of a liquid by passing it through a measuring device in a continuous stream using mechanical stress and measuring the pressure drop and can be used in heat supply and industrial heat power engineering.

A known method of determining gas flow in a gas pipeline system, including measuring the pressure and temperature of the transported gas, moreover, the pressure and gas temperature is measured at the inlet and outlet of a supercharger connected to a controlled pipeline, separated from the rest of the gas pipeline system, measuring the number of revolutions of the supercharger, while the gas flow determined when sharing passport dependence and dependence, connecting the parameters of the transported gas [1]
The disadvantages of this method are its complexity, due to the presence of a supercharger with a known passport dependence, as well as the low accuracy of determining gas flow indirectly, based on the joint use of a passport dependence and a relationship linking the parameters of the transported gas.

 There is a method of determining gas flow in multi-line gas pipelines by sequentially measuring gas flow and pressure losses in their sections, first with the open and then with the closed position of the shut-off element between them, and measure the total gas flow in the gas pipeline section and the pressure at the beginning and end of it when open and then with the closed position of the locking element on the jumper between the pipelines, and the flow rate is determined from the ratios indicated in the claims. This method of determining gas consumption as the closest to the proposed technical solution for the combination of essential features is its closest analogue.

 The disadvantages of this method are its complexity, due to the need to measure controlled parameters at several points outside the measuring unit, as well as to the low accuracy of determining gas flow indirectly, based on the solution of complex mathematical relationships with the substitution in them of values measured by various control -measurement devices with various systematic errors.

 In known methods, in order to simplify the determination of the total flow rate of the medium for objects connected to the pipeline network, among other devices, flow meters are used that are installed on one of the sections of this network (in the measuring unit, in the heat point, etc.), common to all objects. When these flowmeters are connected to each object individually, their readings can significantly shift to the region of lower flow values, measured with an increased error. On the other hand, turning off or switching objects in the network leads to a change in its hydraulic characteristic, which can significantly distort the actual distribution of water among objects and requires the introduction of additional operations necessary for correcting these distortions into known methods for determining the flow rate of fluids.

 The technical result from the use of the invention is to simplify and improve the accuracy of determining the flow of water from the objects of the looped heat network from the heat point of the network.

 This result is achieved in that in a method for determining water flow, which includes sequential measurement of the total flow of water and pressure losses in the network, first when the shutters are open and then closed, according to the invention, after measuring the water flow and pressure losses in the network with open locking elements at all objects, one of the objects is switched off sequentially, then the pressure losses in the network are adjusted until they are equal to the pressure losses in the network, measured before shutting down selected object, and the flow rate of this object is determined by the difference of two consecutive flow values measured before and after the shutdown of the object. Measurements and regulation are performed at the heating point of the network. Water consumption is measured at facilities whose minimum water consumption exceeds the error in measuring water consumption.

 The drawing shows a diagram of a device that implements the method.

 The method is implemented as follows.

G_i=G_н и потерь давления в сети Δр Р_н-Р_k при открытых запорных органах 7-15 на всех объектах 0₁, 0₂.O_n последовательно отключают какой-либо один из объектов, например, 0₁, закрывая запорные органы 7 и 9, затем, при помощи арматуры, установленной в теплопункте, регулируют потери давления Δр' Р_н' Р_k' в сети до выравнивания их с потерями давления Δр в сети, измеренными перед отключением выбранного объекта 0₁. Расход воды через этот объект определяют по разности двух последовательных значений расхода, измеренных до и после отключения объекта 0₁, т.е. G₁=

G_i-

G_i Аналогично определяют расход воды G₂ и т.д. до G_n. Погрешность измерения расхода воды по каждому объекту определяют из следующих соотношений:
G₁+G₂++G_n=

G $\genfrac{}{}{0ex}{}{\text{p}}{\text{i}}$ ;

G $\genfrac{}{}{0ex}{}{\text{p}}{\text{i}}$ -

G_i=

G_i;
^ΔGi⁼

G_ист G_i ± ΔG_i
Измерения и регулирование производят в тепловом пункте сети. При этом, измеряют расход воды по объектам, минимальное водопотребление которых превышает погрешность измерения расхода воды ( ± ΔG_i).During the operation of the heating system, hot water enters the heating station 1 through the supply and return manifolds 2 and 3 with the fittings 4, 5 and 6 installed on them. From the supply manifold 2, water is distributed over the volumes 0 ₁ , 0 _2. О _n connected to the heating system through the shutoff valves 7-15. After measuring the total water flow

G _i = G _n and pressure losses in the network ΔР Р _n -Р _k with open shutoff organs 7-15 at all objects 0 ₁ , 0 ₂ .O _n sequentially turn off one of the objects, for example, 0 ₁ , closing the shut-off bodies 7 and 9, then, using the fittings installed in the heat point, regulate the pressure loss Δр 'Р _н ' Р _k 'in the network until they are equalized with the pressure loss Δр in the network, measured before turning off the selected object 0 ₁ . The water flow through this object is determined by the difference of two consecutive flow values measured before and after turning off the object 0 ₁ , i.e. G ₁ =

G _i -

G _i Similarly determine the flow rate of G ₂ , etc. to G _n . The error in measuring water flow for each object is determined from the following ratios:
G ₁ + G ₂ ++ G _n =

G $\genfrac{}{}{0ex}{}{\text{p}}{\text{i}}$ ;

G $\genfrac{}{}{0ex}{}{\text{p}}{\text{i}}$ -

G _i =

G _i ;
^ΔG i ⁼

G _East G _i ± ΔG _i
Measurements and regulation are performed at the heating point of the network. At the same time, the water flow rate is measured for objects whose minimum water consumption exceeds the error in measuring the water flow rate (± ΔG _i ).

 The exclusion of measurements of flow rate and loss of water pressure at the facilities of the looped heat network is ensured by the possibility of obtaining all the necessary and sufficiently accurate information to determine the flow of water for all and individual objects in a common area of this heating network for all objects, which allows you to concentrate the necessary measuring instruments in one protected place , for example, in a heat point, reduce the fleet of measuring instruments and increase the convenience of its maintenance. At the same time, the efficiency of using heat points is increased.

Improving the accuracy of determining the flow rate for objects from the heat point is provided due to:
use for determination of water consumption of all objects as a whole and each of them individually the same measuring instruments with constant systematic error;
reducing the error in determining the flow rate for the objects, due to a change in the hydraulic characteristics of the network between the objects after their switching, which is achieved by regulating the pressure losses in the network before aligning them with the pressure losses in the network, measured before disconnecting the selected object.

 reducing the time for determining the water flow rate for all objects and the time for checking the convergence of the results obtained when measuring the total water flow rate and after arithmetic addition of the water flow rate for each object.

Claims (3)

 1. METHOD FOR DETERMINING WATER CONSUMPTION BY OBJECTS OF A CIRCULATED HEAT NETWORK, including sequential measurements of the total water flow and pressure losses in the network, first with the open and then closed positions of the shut-off elements at its facilities, characterized in that after measuring the water flow and pressure losses in networks with open shutoffs at all objects sequentially shut off one of the objects, regulate the pressure loss in the network until they equalize with the pressure loss in the network, measured before shutting down th object, and the flow rate of the object is determined from the difference between two successive flow values measured before and after disconnection of the object.  2. The method according to claim 1, characterized in that the measurement and regulation are carried out in the heating point of the network.  3. The method according to claim 2, characterized in that the water flow rate is measured for objects whose minimum water consumption exceeds the measurement error of the water flow rate.

Images