Gravity flow device for long-distance pipe network of city heat supply

Abstract

The application discloses a gravity flow device for a long-distance pipe network of urban heat supply, which comprises water supply pipelines for supplying water from low positions to high positions step by step, and water return pipelines for returning water from high positions to low positions step by step, wherein the water supply pipelines and the water return pipelines form a circulation, and the water return pipelines return water step by step by using gravity flow static pressure. The application fully utilizes natural height differences of a city, forms fluid pressure differences, and adopts a step-by-step water supply mode to supply water from low positions of the city to high positions of the city. In the water return process, the natural height differences of the city are fully utilized, and the water return pipelines return water step by step by using gravity flow static pressure, so as to realize gravity flow water return of the water return pipeline network. The gravity flow water return not only saves heat exchange temperature differences and improves heat supply capacity of the pipeline network, but also realizes the purpose of reducing working pressure of the heat supply pipeline network by grading and pressure reduction of traditional heat exchange stations, and effectively solves the adverse effects of topographic height differences on the long-distance heat supply pipeline network.

Description

Technical Field

[0001] This invention relates to a gravity flow device for long-distance urban heating pipelines. Background Technology

[0002] The significant differences in urban topography necessitate substantial investments in "one city, one network" and long-distance transmission with large temperature differences, severely hindering the green and low-carbon development of heating in cities with significant topographical differences.

[0003] Existing traditional long-distance pipeline heating technology with large temperature differences uses multi-stage pressure relief stations to achieve hydraulic zoning. At these stations, heat exchangers are used to achieve system pressure isolation, reducing the pressure on the pipeline network and ensuring safe operation. However, in this traditional method, nearly 50% of the temperature difference in the pipeline network is used for staged heat exchange, which seriously reduces the network's heat transmission capacity. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a gravity flow device for urban heating long-distance pipelines that utilizes the natural elevation differences in cities to achieve gravity flow return water in the return water network.

[0005] The technical solution for implementing the present invention is as follows:

[0006] The urban heating long-distance pipeline gravity flow device includes a water supply pipeline that supplies water from a low level to a high level in stages, and a return pipeline that returns water from a high level to a low level in stages. The water supply pipeline and the return pipeline form a circulation, and the return pipeline uses gravity flow static pressure to return water in stages.

[0007] Furthermore, the water supply pipeline includes multiple water supply units connected in sequence. Each water supply unit includes a water supply pump, a check valve, and a water supply pipe. The check valve is installed at the output end of the water supply pump, and the water supply pipe is connected to the water supply pump in the adjacent water supply unit.

[0008] Furthermore, the return water pipeline includes multiple return water units connected in sequence. Each return water unit includes a distributor and a collector. Due to the pressure difference caused by the elevation difference between the distributor and the collector, the fluid pressure in the distributor is higher than that in the collector. The water in the distributor flows to the collector by gravity. At least one gravity return water pipeline is arranged between the distributor and the collector to allow the water in the distributor to flow to the collector in stages and at constant pressure.

[0009] Furthermore, when multiple gravity return water pipes are arranged between the distributor and the collector, these multiple gravity return water pipes are arranged in parallel between the distributor and the collector.

[0010] Furthermore, the gravity return water pipeline includes a multi-component tiered constant pressure return water pipeline, which are arranged in series.

[0011] Furthermore, each group of graded constant pressure return water pipelines includes a graded constant pressure return water pipe, and a ball valve, a filter, a pilot-operated flow-limiting constant pressure valve, a pilot-operated level control valve, and a water tank installed sequentially on the graded constant pressure return water pipe;

[0012] Water from the distributor is introduced through the graded constant pressure return water pipe, passes through the ball valve, filter, pilot-operated flow limiting constant pressure valve, pilot-operated liquid level control valve, enters the water tank, and then flows into the next graded constant pressure return pipeline.

[0013] Furthermore, each group of graded constant pressure return water pipelines includes a graded constant pressure return water pipe, and a ball valve, a filter, and a self-closing pilot-operated flow-limiting constant pressure valve installed sequentially on the graded constant pressure return water pipe;

[0014] Water from the distributor is introduced through the graded constant pressure return water pipe, passes through the ball valve, filter, and self-closing pilot-operated flow limiting and constant pressure valve, and flows into the next graded constant pressure return pipeline.

[0015] Furthermore, each group of graded constant pressure return water pipelines includes a graded constant pressure return water pipe, and a ball valve, a filter, a pilot-operated flow-limiting constant pressure valve, and a solenoid valve installed sequentially on the graded constant pressure return water pipe;

[0016] Water from the distributor is introduced through the graded constant pressure return water pipe, passes through the ball valve, filter, pilot-operated flow limiting constant pressure valve, and solenoid valve, and flows into the next graded constant pressure return pipeline.

[0017] By adopting the above technical solution, the urban heating long-distance gravity flow return water system uses a step-by-step water supply method to deliver water from the lower to the higher elevations of the city. During the return process, the natural elevation difference of the city is fully utilized, and the return water pipeline adopts gravity flow static pressure step-by-step return water to achieve gravity flow return water in the return water network. This not only saves heat exchange temperature difference and improves the heat transmission capacity of the pipeline network, but also achieves the purpose of reducing the working pressure of the heating pipeline network by tiered pressure setting of traditional heat exchange stations, effectively solving the adverse effects of terrain elevation difference on long-distance heating pipeline networks. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a single-stage gravity flow return water embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of a multi-stage gravity flow recirculation implementation method of the present invention;

[0020] Figure 3 This is a schematic diagram of the second embodiment of the single-stage gravity flow return water of the present invention;

[0021] Figure 4 This is a schematic diagram of the second embodiment of the multi-stage gravity flow recirculation method of the present invention;

[0022] Figure 5This is a schematic diagram of the third embodiment of the single-stage gravity flow return water of the present invention;

[0023] Figure 6 This is a schematic diagram of the third embodiment of the multi-stage gravity flow recirculation method of the present invention;

[0024] In the attached diagram, 1 is the water supply pipeline, 2 is the return water pipeline, 3 is the water supply unit, 4 is the water supply pump, 5 is the check valve, 6 is the water supply pipe, 7 is the return water unit, 8 is the water distributor, and 9 is the water collector.

[0025] 101 is a graded pressure-regulating return water pipe, 102 is a ball valve, 103 is a filter, 104 is a pilot-operated flow-limiting pressure-regulating valve, 105 is a pilot-operated level control valve, and 106 is a water tank.

[0026] 201 is a graded constant pressure return water pipe, 202 is a ball valve, 203 is a filter, and 204 is a self-closing pilot-operated flow limiting and constant pressure valve.

[0027] 301 is a graded pressure-regulating return water pipe, 302 is a ball valve, 303 is a filter, 304 is a pilot-operated flow-limiting pressure-regulating valve, and 305 is a solenoid valve. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] See Figure 1-6 The gravity flow device for urban heating long-distance pipeline network includes a water supply pipeline 1 that supplies water from a low level to a high level in stages, and a return water pipeline 2 that returns water from a high level to a low level in stages. The water supply pipeline 1 and the return water pipeline 2 form a circulation. The outlet end of the water supply pipeline 1 is connected to the inlet end of the return water pipeline 2, and the outlet end of the return water pipeline 2 is connected to the inlet end of the water supply pipeline 1, thereby forming a circulation between the water supply pipeline 1 and the return water pipeline 2. Due to the elevation difference in urban terrain, the return water pipeline 2 in this application adopts gravity flow static pressure staged return water.

[0030] The water supply pipeline 1 includes multiple water supply units 3 connected in sequence. Each water supply unit 3 includes a water supply pump 4, a check valve 5, and a water supply pipe 6. The check valve 5 is installed at the output end of the water supply pump 4. The water supply pipe 6 is connected to the water supply pump in the adjacent water supply unit 3. The check valve prevents backflow of water supply. A butterfly valve can also be installed at the output end of the water supply pump for control.

[0031] The return water pipeline 2 includes multiple sequentially connected return water units 7. Each return water unit 7 includes a distributor 8 and a collector 9. Due to the height difference between the distributor 8 and the collector 9, there is a pressure difference. The fluid pressure in the distributor 8 is higher than that in the collector 9, and the water in the distributor 8 flows to the collector by gravity. The height difference between the distributor 8 and the collector can be achieved by arranging the distributor 8 and the collector at different heights, or by having the outlet of the distributor 8 higher than the inlet of the corresponding collector.

[0032] At least one gravity return water pipe is installed between the distributor 8 and the collector to allow water in the distributor 8 to flow to the collector in stages at constant pressure. This gravity return water pipe enables multi-stage reflux of water from the distributor, with each stage flowing to the collector at a constant pressure. When multiple gravity return water pipes are installed between the distributor and the collector, these pipes are connected in parallel. This allows water in the distributor to flow to the collector simultaneously through multiple pipes, achieving pressure distribution and stabilizing system operation.

[0033] Each gravity-flow return water pipeline includes multiple sets of tiered constant-pressure return water pipelines, which are arranged in series to enable the water in each return water pipeline to return in a multi-stage constant-pressure manner.

[0034] In this application, the first implementation method for achieving single-stage gravity flow return water is described below: Please refer to... Figure 1 Multiple graded constant pressure return water pipelines are connected in parallel between the water distributor 8 and the water collector 9. Each graded constant pressure return water pipeline includes a graded constant pressure return water pipe 101, and a ball valve 102, a filter 103, a pilot-operated flow-limiting and pressure-regulating valve 104, a pilot-operated level control valve 105, and a water tank 106 installed sequentially on the graded constant pressure return water pipe. Water from the water distributor is introduced through the graded constant pressure return water pipe 101, passes through the ball valve 102, the filter 103, the pilot-operated flow-limiting and pressure-regulating valve 104, the pilot-operated level control valve 105, enters the water tank 106, and then flows to the water collector.

[0035] Specific Explanation: In this implementation, the return water from the pipeline enters the distributor from the bottom through a pipe. The distributor branches into multiple outlets. Each branch passes through a ball valve, filter, pilot-operated flow-limiting and pressure-regulating valve, and pilot-operated level control valve before entering the water tank. The branches from the water tank outlet converge into the collector, and the return water flows to the next stage through the bottom of the collector. The pilot-operated flow-limiting and pressure-regulating valve maintains the outlet pressure at a set value, and the pilot-operated level control valve controls the water tank level within a set range. During normal operation, the opening degree of the pilot-operated hydraulic control valve core dissipates the excess pressure of the gravity-flow return water, ensuring that the pressure after the valve does not exceed the set value.

[0036] When the water level in the tank exceeds the upper limit, the pilot-operated level control valve closes via a float switch. If excessive pressure is detected downstream of the valve, the pilot-operated flow-limiting and pressure-regulating valve automatically closes. This dual protection system, consisting of the pilot-operated level control valve and the pilot-operated flow-limiting and pressure-regulating valve, solves the problem of incomplete valve closure in the pipeline. The new urban heating long-distance gravity-flow return water system achieves both the elimination of pressure-reducing stations in large temperature difference long-distance pipelines and the staged pressure-regulating effect of traditional pressure-reducing stations, while ensuring that the working pressure at all points in the pipeline network remains at the set value.

[0037] In this application, the first implementation method for achieving multi-stage gravity flow recirculation is described below: Please refer to... Figure 2 Based on the multi-stage gravity flow return water system constructed by sequentially connecting the above-mentioned single-stage gravity flow return water implementation method, the water from the upper-stage water collector enters the lower-stage water distributor, is divided by the upper-stage water distributor, and enters the water collector of that stage, and then sequentially enters the next stage water collector. Through the multi-stage constant pressure gravity flow return water method, the return water pipeline can be stably operated to meet the long-distance return water transportation requirements of urban heating pipe networks.

[0038] In this application, the second implementation method for achieving single-stage gravity flow return water is described below: Please refer to... Figure 3 Multiple graded constant-pressure return water pipelines are connected in parallel between the distributor 8 and the collector 9. Each graded constant-pressure return water pipeline includes a graded constant-pressure return water pipe 201, and a ball valve 202, a filter 203, and a self-closing pilot-operated flow-limiting and pressure-regulating valve 204 installed sequentially on the graded constant-pressure return water pipe. Water from the distributor flows to the collector through the graded constant-pressure return water pipeline, passing through the ball valve, filter, and self-closing pilot-operated flow-limiting and pressure-regulating valve. This method achieves constant-pressure transmission at each stage through the self-closing pilot-operated flow-limiting and pressure-regulating valve.

[0039] In this application, the second implementation method for achieving multi-stage gravity flow recirculation is described below: Please refer to... Figure 4 Based on the multi-stage gravity flow return water system constructed by sequentially connecting the above-mentioned single-stage gravity flow return water implementation method 2, the water from the upper-stage water collector enters the lower-stage water distributor, is divided by the upper-stage water distributor, and enters the water collector of that stage, and then sequentially enters the next stage water collector. Through the multi-stage constant pressure gravity flow return water method, the return water pipeline can be stably operated to meet the long-distance return water transportation requirements of urban heating pipe networks.

[0040] In this application, the third implementation method for achieving single-stage gravity flow return water is described below: Please refer to... Figure 5Multiple graded pressure-regulating return water pipelines are connected in parallel between the distributor 8 and the collector 9. Each graded pressure-regulating return water pipeline includes a graded pressure-regulating return water pipe 301, and a ball valve 302, a filter 303, a pilot-operated flow-limiting pressure-regulating valve 304, and a solenoid valve 305 installed sequentially on the graded pressure-regulating return water pipe. Water from the distributor flows to the collector through the graded pressure-regulating return water pipeline, passing through the ball valve, filter, pilot-operated flow-limiting pressure-regulating valve, and solenoid valve. This method achieves gravity-flow pressure-stabilized return water through the cooperation of the pilot-operated flow-limiting pressure-regulating valve and the solenoid valve.

[0041] In this application, the third implementation method for achieving multi-stage gravity flow recirculation is described below: Please refer to... Figure 6 Based on the multi-stage gravity flow return water system constructed by sequentially connecting the above-mentioned single-stage gravity flow return water implementation method three, the water from the upper-stage water collector enters the lower-stage water distributor, is divided by the upper-stage water distributor, and enters the water collector of that stage, and then sequentially enters the next stage water collector. Through the multi-stage constant pressure gravity flow return water method, the return water pipeline can be stably operated to meet the long-distance return water transportation requirements of urban heating pipe networks.

[0042] In summary, addressing the shortcomings of traditional high-temperature long-distance pipeline heat exchange technologies, such as low heat transfer efficiency due to pressure isolation in heat exchangers and high investment costs, this application proposes a novel gravity flow device for urban heating long-distance pipelines. A water pump pressurizes the supply water in the lower zone and sends it to the radiators in the higher zone to release heat. The water then returns to the higher zone via gravity flow, passing sequentially through a ball valve, filter, pilot-operated flow-limiting and pressure-regulating valve, and pilot-operated level control valve before entering a water tank to release static pressure. The water then flows by gravity to subsequent water tanks and finally to the pump inlet, forming a cycle. This inversion process—pressurized flow—unpressurized flow—allows for a smooth transition from high-pressure to low-pressure fluid, thus enabling direct connection and grid-connected heating for large temperature difference pipelines.

[0043] The novel gravity flow device for long-distance urban heating pipelines proposed in this application integrates the long-distance pipeline network into a unified system. The water supply pipeline system is identical to the traditional multi-stage water supply pipelines, but the total pump head is higher than that of traditional long-distance pipelines. The return water pipe utilizes a novel gravity flow return water device to stabilize pressure and limit flow, allowing water to flow to the next stage. Compared to traditional large-temperature-difference long-distance pipeline heat exchange technology, this reduces heat exchange temperature difference losses caused by heat exchangers, improves the system's heating capacity, reduces initial equipment investment and land use, and significantly lowers investment costs.

Claims

1. A gravity flow device for long distance pipe network of city heat supply, characterized in that, The water supply pipeline includes water supply from low to high, and the water return pipeline returns water from high to low, the water supply pipeline and the water return pipeline form a cycle, and the water return pipeline returns water by gravity flow static pressure; The water supply pipeline includes a plurality of sequentially connected water supply units, each water supply unit includes a water supply pump, a check valve, and a water supply pipeline, the check valve is installed at the output end of the water supply pump, and the water supply pipeline connects the water supply pumps in adjacent water supply units; The water return pipeline includes a plurality of sequentially connected water return units, the water return unit includes a water distributor and a water collector, the pressure difference between the water distributor and the water collector is caused by the height difference, the fluid pressure of the water distributor is higher than that of the water collector, and the water in the water distributor flows to the water collector by gravity; at least one gravity flow water return pipeline is arranged between the water distributor and the water collector to make the water in the water distributor flow to the water collector at a graded constant pressure; When a plurality of gravity flow water return pipelines are arranged between the water distributor and the water collector, the plurality of gravity flow water return pipelines are arranged in parallel between the water distributor and the water collector; The gravity flow water return pipeline includes a plurality of groups of graded constant pressure flow return pipelines, and the plurality of groups of graded constant pressure flow return pipelines are arranged in series; Each group of graded constant pressure flow return pipelines includes a graded constant pressure return pipeline, and a ball valve, a filter, a pilot type flow limiting pressure maintaining valve, a pilot type liquid level control valve and a water tank sequentially installed on the graded constant pressure return pipeline; The water from the water distributor is introduced through the graded constant pressure return pipeline, passes through the ball valve, the filter, the pilot type flow limiting pressure maintaining valve and the pilot type liquid level control valve, and then flows into the next stage of the graded constant pressure return pipeline; Each group of graded constant pressure flow return pipelines includes a graded constant pressure return pipeline, and a ball valve, a filter, a self-closing pilot type flow limiting pressure maintaining valve sequentially installed on the graded constant pressure return pipeline; The water from the water distributor is introduced through the graded constant pressure return pipeline, passes through the ball valve, the filter and the self-closing pilot type flow limiting pressure maintaining valve, and then flows into the next stage of the graded constant pressure return pipeline; Each group of graded constant pressure flow return pipelines includes a graded constant pressure return pipeline, and a ball valve, a filter, a pilot type flow limiting pressure maintaining valve and a solenoid valve sequentially installed on the graded constant pressure return pipeline; The water from the water distributor is introduced through the graded constant pressure return pipeline, passes through the ball valve, the filter, the pilot type flow limiting pressure maintaining valve and the solenoid valve, and then flows into the next stage of the graded constant pressure return pipeline.

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