RU2089790C1 - Method of control of distribution of heat carrier in heat supply system - Google Patents

Abstract

FIELD: heat supply. SUBSTANCE: required pressure is maintained in the reverse pipe line in the portion connected to the additional heat source due to making-up by pumps from the major reverse pipe line connected with the major heat source. EFFECT: simplified method. 3 cl, 1 dwg

Description

 The invention relates to heat supply systems and can be used in the presence of an additional heat source.

Two varieties of heat supply networks are known: radial or dead-end [1] and ring [2]
An annular system usually has a trunk pipeline of constant cross-section, combining two or more thermal stations, including additional heat sources, such as waste heat boilers. Distribution networks of variable section are connected to the main pipeline, to which consumers are connected. Such a system is convenient in operation, is easily controlled depending on seasonal fluctuations in the volume of consumption by connecting or disconnecting additional heat sources, as well as carrying out repair work of one or another thermal station one by one. But it requires significant capital costs due to the presence of a pipeline of constant cross section.

 Dead-end networks are used for small systems and, as a rule, are not reserved by additional heat sources.

 However, in practice, in operating systems, sometimes situations arise when an additional source with constant heat release appears at the end of one of the branches of the heating network.

 The objective of the invention is the rational use of this heat source without major alteration of the existing dead-end heating system.

The existing dead-end heat supply system is known, which contains a central boiler room, connected in parallel with an additional boiler heat converter, as well as with a recovery boiler installed at the end of one of the branches of the heating network in an electrothermal workshop for the production of crystalline silicon. The central boiler room is connected with consumers with direct and reverse pipelines of variable cross-section with a diameter of 480,377 mm to the crystalline silicon workshop [3]
The known system adopted as a prototype allows to reduce the heat consumption of the central boiler room by using the heat of the recovery boiler in the crystalline silicon workshop. The heat of the recovery boiler covers the workshop's own needs throughout the year.

 The regulation of the distribution of the heat carrier of the known heat supply system is as follows. In winter, the central boiler house operates at full load, providing heat to all consumers, except for the silicon workshop, which is supplied with heat all year round by a waste heat boiler. In the summer, the central boiler house operates with less load due to a decrease in consumer demand.

 At the same time, the recovery boiler operates with a constant load both in winter and in summer. In the summer period, he transfers part of this heat to the consumers closest to him, who in the winter period were supplied with heat from the central boiler room.

 To implement this method of regulating the distribution of heat carrier, the existing heat supply system is equipped with valves installed on the main direct and return pipelines at the inlet to the silicon workshop, as well as at the inlet of that part of the additional consumers that are supplied with heat from the recovery boiler during transition periods.

 A disadvantage of the known method of regulating the distribution of the coolant is that only a small part of the consumers closest to it transfer heat to the heat recovery boiler during the transition period, although it has potential capabilities to satisfy most of the consumers. This is due to the fact that the diameter of the main pipeline increases from the waste heat boiler towards the central boiler room. Therefore, the pressure in it decreases with distance from the waste heat boiler. Therefore, the existing method of distribution of the coolant and the system for its implementation are not effectively using the potential capabilities of the recovery boiler.

 The efficiency of the existing method of distribution of the coolant and the system for its implementation could be improved by replacing the pipeline of variable cross-section with an annular constant cross-section [2], but such a replacement may require significant capital costs, which may soon pay off.

 The purpose of this method of distributing the heat carrier and the system for its implementation is to increase the efficiency of using a constant additional heat source from the recovery boiler without replacing the existing heat networks of variable cross-section.

 This goal is achieved in that the regulation of the distribution of the coolant in the heat supply system using the main heat source and additional, interconnected by the main direct and return pipelines of variable cross-section with consumers connected to it, including maintaining the necessary heat consumption in the system from one and the other heat source by periodically and sequentially connecting part of the consumers closest to the additional heat source and connected to the main pipe ode, and respectively off these customers from the main source of heat is performed so that the area in the system connected to a further source of heat consumers is maintained the desired pressure in the return conduit Drains from the main pump return pipe connected to the main heat source.

 The essence of the proposed method and system for its implementation is that in the presence of two sources of heat, the main and additional, connected by the main direct and reverse pipelines of variable cross-section, switching part of the consumers connected to this pipeline to supply heat from the main heat source to additional is associated with certain difficulties. These difficulties lie in the fact that in a pipeline of variable cross section, which increases with distance from an additional heat source, pressure drops.

 To maintain this pressure at the required level, the coolant from the main return pipe connected to the main heat source is pumped under the pressure of the required size to the return pipe connected at that moment to the additional heat source.

 Thus, the coolant coming from an additional heat source gives off heat to the consumer, and the pressure in this section is maintained by replenishment from the main trunk pipeline.

 This embodiment provides economical fuel consumption from the main heat source. While the technical solution of the prototype provides coverage of heat consumption only for their own needs and a small part of the consumers closest to it, and the excess heat does not find rational use. Therefore, the proposal meets the criteria of the invention of "novelty."

 To compare the proposals with other well-known solutions, a search was conducted on patent and scientific and technical literature. In none of the known solutions did we find a method for distributing a coolant similar to the one proposed.

 Therefore, this proposal meets the current level of technology.

 The drawing shows a heat supply scheme from two heat sources, which shows the main heat source as the central boiler 1, connected by direct 2 and return 3 pipelines of variable cross-section, decreasing with distance from the central boiler, with an additional constant heat source by the recovery boiler 4. From the main the main pipeline direct 2 and return 3 there are taps to consumers 5 9. The waste heat boiler 4 is part of the technical equipment installed in the workshop and is connected with consumers 10 and 11 installed in the workshop, direct 12 and return 13 pipelines. The waste heat boiler 4 has its own valves 14, 15 and valves 16, 17, connecting it to the main pipelines 2 and 3.

 To connect additional consumers 9 7 to the waste heat boiler 4, the system is equipped with sectional valves 18 20 on the direct pipe 2 and, accordingly, sectional valves 21 23 on the return 3.

 On the return pipe 3 in the place of separation of additional consumers 9 7 are installed makeup pumps 24 26, connected by-pass piping 27 29 to the two sides of each valve 21 23.

 To maintain the required pressure in the return line 3, pressure regulators 30 32 are installed behind the make-up pumps 24 26.

 To prevent freezing of water in the direct pipe 2 with closed sectional valves 18 20 bypasses are provided in the form of jumpers 33 - 35, connecting the direct 2 and return 3 pipelines in front of these valves. Jumpers 33 35 bypass equipped with valves 36 38.

 Example 1. The waste heat boiler is shut off by valves 14, 15, for example, during furnace loading or repair. In this case, the heat supply to consumers 5 11 is carried out from the central boiler 1 according to the usual known scheme. At the same time, the sectional valves 18 23 are opened, the pumps 24 26 do not work, and the valves 36 38 bypasses are closed.

 Example 2. Winter mode. The central boiler 1 operates at maximum load and supplies heat to consumers 5 9. The waste heat boiler 4 operates in the usual technological mode and supplies heat to shop consumers 10, 11.

 To perform the heat supply according to this scheme, the valves 14, 15 are opened and the valves 16, 17 are closed.

 Example 3. Summer mode. At the beginning of the heating period, the thermal load on consumers is minimal. By generating a constant amount of heat, the recovery boiler can provide a maximum number of consumers 7 9, as well as 10, 11. For this, the valves 20 and 23 are closed, the bypass valve 38 on the jumper 35, if necessary, open and turn on the pump 26.

 The specified mode provides the minimum economical work load of the central boiler room, which supplies heat to consumers 5, 6, and the waste heat boiler supplies all the rest.

 In this mode, the heat carrier from the recovery boiler enters, in addition to consumers 10, 11, to consumers 9 7 through the main main pipe 2 and through the return pipe 3 to the recovery boiler 4. In the main pipe, the maximum heat carrier pressure is provided at the outlet of the recovery boiler 4 4.5 ati. On the way of the coolant to the distant consumer 7 there are natural pressure losses due to friction in the pipeline. The pressure loss in the direct pipeline was, for example, 2 ati and in the reverse also 2 ati. In addition, the available pressure at the last consumer 7 was 0.5 ati. Thus, the total pressure loss was 4.5 ati.

 For normal operation of the system, it is necessary that the pressure in the return pipe be at least 0.5 ati at the highest consumer. This task is performed by a make-up pump 26 and a pressure regulator 32 by pumping water from the return pipe 3 of the central boiler room 1 through the bypass pipe 29 to the return pipe 3 of the recovery boiler 4 cycle.

 Example 4. Winter mode. With a decrease in the outdoor air temperature, heat consumption by consumers increases. Since the recovery boiler generates a constant amount of heat regardless of the season, the number of consumers connected to it should be reduced.

 This operation is performed as follows.

 Sectional valves 20 and 23 are opened, and the valves 19 and 22 are closed, the valve 38 is closed, and the bypass valve 37 is opened, the pump 26 is turned off and the pump 25 is turned on.

 Thus, the consumer 7 moved from the cycle of the recovery boiler to the cycle of the central boiler room. Naturally, the heat consumption of the central boiler room has increased, and the waste heat boiler provides the necessary amount of heat to the consumers remaining in its cycle.

 With a further decrease in the outdoor temperature, consumer 8 is similarly turned off, etc.

 The modern development of technology makes it possible to automate the above-described process of transition from one operating mode to another by compiling a program for each mode embedded in the computer, and thus ensure prompt translation of the system to any of them.

 Thus, the proposed method of distribution of the coolant and the system for its implementation provide the efficient use of an additional heat source without replacing the existing heating systems of variable cross-section and provide a quick transfer from one mode to another.

Claims (4)

 1. A method of regulating the distribution of coolant in a heat supply system using primary and secondary heat sources, interconnected by main direct and return pipelines of variable cross-section with consumers connected to it, including maintaining the necessary heat consumption in the system depending on the amount of consumption and redistributing the heat consumption in the system from one and the other source by periodically and sequentially connecting (or disconnecting) part of the consumers closest to additional heat source and connected to the main pipeline, and the corresponding disconnection (or connection) of these consumers from the main heat source, characterized in that in the system in the area connected to the additional heat source consumers maintain the required pressure in the return pipe by feeding pumps from the main return a pipeline connected to the main heat source.  2. A system for regulating the distribution of heat carrier in the heat supply system using the main and additional heat sources, containing the main heat source, the central boiler room and the additional - the production waste heat boiler, interconnected by the main direct and return pipelines of variable cross-section, a network of consumers connected to the main pipelines , characterized in that on the main pipeline in the place of connection of some consumers closest to the additional heat source, mouth ovleny sectional plugs or valves for connection (or disconnection) of this supply and, accordingly, disconnect (or connection) from the main heat source, and in the return line to both sides of the sectional plugs that part of consumers connected bypass piping associated with the boost pump.  3. The system according to claim 2, characterized in that, to maintain the necessary pressure in the return pipe, pressure regulators are installed behind the feed pumps.  4. The system according to claim 2, characterized in that in order to prevent freezing of water in the direct main pipe with closed sectional plugs, bypasses are installed in front of these plugs in the form of jumpers connecting the direct and return pipelines equipped with plugs.