RU2314457C1 - Method to provide designed flow rate of heat carrier - Google Patents

Abstract

FIELD: heat power engineering.

SUBSTANCE: invention relates to heat supply and it can be used in open heat supply system of residential and industrial buildings at dependent connection to heat supply system. Proposed method to provide designed flow rate of heat carrier in nonautomated heat center of open-type heat supply system with dependent connection of stand pipes of circulation circuit of hot water supply system, heating ventilation and water-to-water elevator of heating system equipment with commercial heat energy metering unit comes to measuring and regulating designed flow rate of system water passing in turn into heating ventilation system and into hot water supply water stand pipes. Basing on actual readings of heat energy metering devices owing to passing of system water flow through bypass pipelines of shutoff valves with reduced diameter, linear head losses are increased and head before heating system is preserved to provide stable operation of water-to-water elevator.

EFFECT: provision of optimum heat and hydraulic conditions of nonautomated heat center within the limits of values provided by actual operating conditions of district heat supply system.

3 cl, 1 dwg

Description

The invention relates to a power system, namely to heat supply, and can be used in open heat supply systems of residential, public and industrial buildings with a dependent scheme of connection to a heat network.

After installing a commercial unit for metering thermal energy at non-automated heating centers of residential, public and industrial buildings, a problem usually arises regarding the optimization of the thermal and hydraulic modes of operation of the heat supply system. This is due to the technical conditions for installing the flow meters, a decrease in the diameter of the corresponding sections of the supply and return pipes and the additional pressure losses associated with this.

A typical heat supply scheme includes: a pipeline of a hot water supply system with a water supply with heated towel rails and circulation pipelines; pipeline to heat-using installations of the heating ventilation system; elevator connection of convection-emitting devices of the heating system. For all types of heat load through adjustment, the coolant costs must be established that provide the standard values of water temperatures for hot water supply and air in heated rooms (see Apartsev MM "Adjustment of water systems for district heating." - M .: Energoatomizdat, 1983, p. 11).

Design decisions on the choice of the diameter of the corresponding pipeline, as a rule, are limited by their capacity and do not take into account the piezometric pressure at the point of their connection to the main or distribution heating network. This circumstance leads to the necessity of carrying out operational adjustment to ensure the estimated coolant costs in the consumer distribution network.

The technical conditions for the subscriber to connect to the water heating network require the consumer to limit the maximum flow rate of the coolant at the input, the energy supply organization, if necessary, conducts the forced installation of throttle devices at the interface.

In conditions of limited available pressure, ensuring the estimated flow rate of the coolant is a difficult task, to the solution of which this technical solution is directed.

The estimated consumption of network water to a heat point and a heat network is composed of the estimated costs for each heat consumption system: heating, ventilation and hot water supply. This flow rate at each heat point is ensured by the appropriate setting of automatic regulators.

There are known methods of using control devices in heating systems (see patent No. 2190163 and No. 2190164), there is a practice of their application on each heating riser and in each heating device (heat sink).

In the absence of automatic regulators, throttling diaphragms are installed, selected according to the estimated flow rate of the network water based on the available pressure at the inlet and the estimated pressure losses in the system.

The calculated pressure losses in the local heating system or in the heat sink are determined by the difference in the total pressure at the beginning and end of the pipeline section when the estimated flow rate of the coolant passes through it. Linear pressure losses (friction losses) and pressure losses in local resistances in a given section of the pipeline are determined by formulas and nomograms. The operations to determine the total, linear and local resistance of the pressure loss are performed while maintaining the estimated flow rate of the coolant.

Due to the complexity of determining the estimated pressure losses in heat supply systems and heat receivers, it is recommended to use a number of assumptions in the technical literature that are not reflected in the development of hydraulic modes of main water networks, but are not always applicable in local systems. So, for example, the excess head, which is defined as the difference between the available head in front of the system (heat sink) and the pressure drop in the system (heat sink) at the calculated flow rate of the coolant, is used in the calculation of orifice plates taking into account all the throttling devices available and planned for installation in this system . In addition, the technical conditions for installing throttle orifice plates, namely: flange or threaded connections, two-way disconnection from the pipeline, impose additional difficulties for their use (see M. Apartsev, “Setting up water central heating systems.” - M .: Energoatomizdat, 1983, p. 58, 59).

A new way to ensure the estimated flow rate of the coolant is that the flow rate of the coolant is determined by the actual readings of the standard flow meter (flow meter of the heat meter), and the regulation is carried out by alternately and jointly switching on the heat consumption systems: heating, ventilation and hot water supply with the corresponding measurement of the total pressure loss in them according to standard attorney manometers.

The solution to the problem of limiting the maximum flow rate of network water to the circulation circuit of the hot water supply and heating ventilation system is by passing a stream through the bypass of the shutoff valves to ensure a sufficient available head in front of the water-water elevator of the heating system.

To implement the method, a bypass pipe (with a diameter of L _Y 15 mm, but not more than 30% of the diameter of the main pipe) is installed of shutoff valves at the coolant inlet to heat-using installations of the heating ventilation system and shutoff valves at the outlet of hot water from the hot water supply system.

The estimated flow rate of the coolant is provided by the regulatory body, which is the bypass (bypass pipe) on the pipelines of the heating ventilation and hot water supply systems, the resistance of which ensures the required pressure loss in these systems and maintains the necessary disposable pressure for the operation of the water-water elevator of the heating system.

Passing the flow of network water through the estimated reduced diameter of the bypass pipe allows the heat supply system to work at the estimated flow rates of the coolant within the required heat consumption, while ensuring hydraulic stability of both the local system and the heating system as a whole.

The proposed method provides, within the limits of the values determined by the actual operating mode of the district heating system, maintaining the standard temperature of hot water in the water intake pipe with a minimum passage of network water into the return pipe, the required temperature of heated air by passing the estimated flow rate of network water from the supply pipe to the ventilation system and the set air temperature in heated rooms by passing the estimated flow rate of network water through the water-water elevator .

To implement this method of providing a calculated flow rate, additional technical means and electronic equipment are not required, but the presence of attorneys of standard devices is sufficient.

Analysis of scientific, technical and patent information shows the lack of coincidence of the distinctive features of the claimed method with the signs of known technical solutions.

The proposed technical solutions have significant features, which together affect the achieved result, namely profitability, the availability of ball valves and small diameter pipes, a quick payback period.

The proposed solution is presented on a schematic flow diagram of a non-automated heat point (see drawing).

An open heat supply system for a non-automated heating unit includes:

a) supply 1 and return 2 network water pipe equipped with temperature sensors 3 and flow meters 4;

b) the supply 5 and return 6 piping of the ventilation system, the supply piping 5 is equipped with bypasses 7 on the common input and 8 on the input to each heat-using ventilation unit;

c) a water-folding 9 and circulation 10 pipeline of a hot water supply system with heated towel rails; a bypass 11 and a non-return valve 12 are installed at the outlet of the circulation pipeline 10 to prevent the selection of a low-temperature coolant from the return pipe;

d) a water-water elevator of the heating system 13 with standard calibrated pressure gauges 14 to ensure uniform distribution of the coolant along the heating pipes as they are removed from the elevator, inserts of reduced diameter 15 are mounted.

The method of providing the estimated flow rate of the coolant and the required available pressure is as follows:

a) according to the testimony of pressure gauges 14 determine the available pressure in front of the filled heat supply system;

b) through the bypass 7 of the inlet valve, the heating ventilation system is connected and set to pass the estimated flow rate of the coolant according to the flow meters 4 and the positions of the bypass ball valves 8 for each heat-using ventilation unit;

c) the position of the bypass ball valve 7 as indicated by the flow meter 4 ensures that the estimated flow rate of the mains water passes into a fully connected heating ventilation system;

g) according to the testimony of pressure gauges 14 determine the available pressure in front of the heating system after connecting the ventilation load;

d) through the bypass 11 of the outlet valve, connect the hot water supply system and configure to pass the estimated circulating flow rate of the network water according to the flow meter 4;

e) according to the readings of pressure gauges 14 determine the available pressure in front of the heating system after connecting the ventilation load and hot water supply;

g) according to the indications of the difference in the flow rate of the flow meters 4, they adjust (by opening the water taps) the analysis of hot water within the average daily maximum consumption during the winter period of use, adjust the flow rate of the network water for ventilation bypass 7;

h) according to the testimony of pressure gauges 14, determine the available pressure in front of the heating system after establishing the calculated water analysis and adjusting the ventilation load;

i) configure the water-water elevator of the heating system to absorb the excess pressure remaining after connecting the ventilation load and hot water supply and to allow the estimated flow rate determined by the heating load to pass into the heating system;

j) according to the readings of flow meters 4, in the absence of a water intake, the total flow rate of the coolant into the heat supply system is checked and the position of the bypass ball valves 7, 8 and 11 is fixed.

k) to ensure uniform distribution of the coolant along the heating risers as they are removed from the elevator, inserts of reduced diameter 15 are mounted, which ensure equalization of the pressure head on each heating riser during operation of the water-elevator elevator.

By implementing the method, the consumer himself using standard devices provides the greatest possible degree of preservation of the hydraulic stability of the consumer distribution network with optimal heat consumption, and during the operation of heat supply systems with a change in hydraulic losses in local systems, the injection mode of the elevator and the normal circulation mode of the ventilation and hot water systems are maintained.

The above information indicates that when using the inventive method, the conditions of "industrial applicability".

Claims (3)

1. A method of providing a calculated flow rate of a coolant of a non-automated heat supply point of an open heat supply system with dependent connection of risers of the circulation circuit of a hot water supply system, heating ventilation and a water-water elevator of a heating system equipped with a commercial heat energy metering unit, characterized in that the calculated flow rate of the network is measured and regulated of water flowing alternately into the heating ventilation system and into hot water supply risers, in fact According to the thermal indications of heat energy meters, by letting the flow of network water through the bypass (bypass) valves of the valves with a reduced diameter, they increase the linear pressure losses in them and maintain the available pressure in front of the heating system, which ensures the stable operation of the water-elevator. 2. The method according to claim 1, characterized in that, regardless of the magnitude of the piezometric pressure at the input of the heat point, the network water pass is bypassed at the inlet of the heat carrier to the heat-using heating ventilation units and at the outlet of the heat carrier from the circulation pipe of the hot water supply system. 3. The method according to claim 1, characterized in that to ensure uniform distribution of the coolant along the risers of the heating system at the outlet of the coolant as they are removed from the water-elevator elevator, the network water is passed through pipe inserts of reduced diameter of the calculated length.