An energy-saving device and method using the siphon capacity of a pipe network

Abstract

The present invention belongs to the technical field of water conservancy engineering, and discloses an energy-saving device and method using the siphon ability of a pipe network. In the energy-saving device using the siphon ability of the pipe network, the top and bottom of a water level tank are respectively connected to the downward pipeline of the top water flow direction of a water supply pipeline through a connecting pipe, and a water level measuring device is installed on the water level tank. The water level tank is installed on the top of a tower-type device or a water supply pipeline, and the highest point of the top of the water supply pipeline is connected to a vacuum pump through a top water outlet pipeline; the water supply pipeline is connected with a circulating water inlet pipe and a circulating water outlet pipe, the circulating water outlet pipe is connected with a regulating valve, and the water level measuring device is a water level gauge or a water level sensor. While making the most of the energy-saving effect generated by siphon, the present invention solves the harm caused by the vacuum generated by siphon to production.

Description

Technical Field

[0001] The invention belongs to the technical field of water conservancy engineering, and in particular relates to an energy-saving device and method utilizing the siphoning capacity of a pipe network. Background Art

[0002] At present, in the water supply system, there are some special structures, such as Figure 3 As shown. The pipeline goes up and then down, forming a convex shape. This structure is more commonly used in tower equipment and water conservancy projects of chemical equipment. In the design process of equipment and pipelines, an exhaust device is generally set at the highest elevation point. Because when the exhaust device is not set, this structure will produce a siphon. The liquid automatically flows from one end with a higher liquid level through a pipeline above the liquid surface to the other end with a lower liquid level. This phenomenon is called siphon. Siphon will cause a vacuum at the high point; and the vacuum may cause the high point to vaporize or even cause air blockage to cause flow interruption. In the actual operation process, it must be ensured that the highest point is in a positive pressure state, but maintaining positive pressure will not utilize the energy-saving effect brought by the siphon. If no siphon is used, it means maintaining a positive pressure state at the highest point of the pipeline. If there is no adjustment means, the flow rate will generally exceed the demand by a large margin, which will waste water on the one hand and lose control of the temperature of the tower equipment on the other hand, so the valve on the outlet pipe must be used for throttling. As long as the valve throttles, energy is essentially wasted through throttling. The amount of energy wasted can be calculated by the following formula: P = ρ·g·Δp·Q; P—lost power (kW); ρ—medium density (kg / m 2 );Δp—pressure difference before and after the valve (m); Q—flow rate through the valve (m 3 / h). Assuming that the natural phenomenon of siphon is fully utilized, the regulating valve can be fully opened, or opened to a greater extent. On the basis of maintaining Q unchanged, the pressure difference Δp before and after the valve can be reduced as much as possible, thereby achieving energy saving. When using siphon to achieve energy saving, it is also necessary to overcome the problem of different pressure requirements for startup and normal operation. At startup, the water supply pressure must be increased so that the water can overcome gravity and reach the highest point of the pipeline. Then the water will flow downward until it fills the pipeline, thus forming a siphon. In this way, the water supply pump must be able to meet the pressure reaching the highest point; at the same time, it must ensure that when the water supply pressure drops during siphon, the pump still operates in the high-efficiency zone, which brings unnecessary difficulties to the selection and design of water pump parameters.

[0003] Through the above analysis, the problems and defects of the existing technology are as follows: the siphon in the existing technology will cause a vacuum at the high point, and the vacuum may cause the high point to vaporize or even cause air blockage and flow interruption. In the actual operation process, it is necessary to ensure that the highest point is in a positive pressure state, but maintaining positive pressure will not have the energy-saving effect brought by the siphon. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides an energy-saving device and method using the siphon capacity of a pipe network.

[0005] The present invention is implemented as follows. An energy-saving device using the siphon capacity of a pipe network is provided with a water level tank.

[0006] The top and bottom of the water level tank are respectively connected to the descending pipe in the water flow direction at the top of the water supply pipe through a connecting pipe, and a water level measuring device is installed on the water level tank.

[0007] Further, the water level tank is installed at the top of a tower-type device or the water supply pipe.

[0008] Further, the highest point at the top of the water supply pipe is connected to a vacuum pump through a top water outlet pipe.

[0009] Further, the water supply pipe is connected with a circulating water inlet pipe and a circulating water outlet pipe.

[0010] Further, the circulating water outlet pipe is connected to a regulating valve.

[0011] Further, the water level measuring device is a water level gauge or a water level sensor.

[0012] Another object of the present invention is to provide an energy-saving method using the siphon capacity of the pipe network by using the above-mentioned energy-saving device using the siphon capacity of the pipe network. The energy-saving method using the siphon capacity of the pipe network includes:

[0013] When vaporization occurs and accumulates at the top of the pipe, and the water level tank is connected to the top of the pipe and there is vapor at the top of the pipe, the water level in the water level tank drops; when the system detects the drop in water level through a water level gauge or a sensor, the regulating valve is adjusted until the water level in the water level tank remains unchanged and the pressure at the top of the pipe is in the most energy-saving state;

[0014] After the valve in the regulating valve is adjusted, the pipe leading to the vacuum system is connected to discharge the air and the remaining steam at the top, so that the introduced air and the generated small amount of vaporization are discharged in time; the suction of the vacuum pump and the closing of the regulating valve both have the external characteristics of reducing the vaporization at the top of the pipe; by adjusting the regulating valve and the vacuum pump, the different pressure requirements during startup and normal operation are solved.

[0015] Further, the specific process of adjusting the regulating valve until the water level in the water level tank remains unchanged when the system detects the drop in water level through a water level gauge or a sensor is as follows:

[0016] When the system detects the drop in water level through a water level gauge or a sensor, the regulating valve is gradually adjusted smaller until the water level in the water level tank remains unchanged and the top pressure is the most energy-saving.

[0017] Furthermore, the specific process of the external features of the vacuum pump's suction and throttle valve closing that reduce the impact of vaporization at the top of the pipeline is as follows:

[0018] When the valve in the throttle valve is throttled down, the frequency of vacuum suction decreases; due to water bringing in air, the vacuum pump conducts suction; in practice, according to different equipment and the gas content of the medium, an appropriate suction frequency is adjusted.

[0019] Furthermore, the specific process of solving the different pressure requirements during startup and normal operation by adjusting the throttle valve is as follows:

[0020] The water supply equipment meets the pressure requirements after siphon startup. When the system starts, the water supply equipment is started and the throttle valve is closed; at the same time, the vacuum pump is started to suck the inside of the pipeline until the water level in the water level tank is equal to the top of the pipeline, then the throttle valve is opened, the valve in the throttle valve is started, and the vacuum pump is disconnected, and the startup is completed.

[0021] Combining the above technical solutions and the solved technical problems, please analyze the advantages and positive effects of the technical solution to be protected by the present invention from the following aspects:

[0022] First, aiming at the technical problems existing in the above prior art and the difficulty of solving this problem, closely combining the technical solution to be protected by the present invention and the results and data during the R & D process, etc., analyze in detail and deeply how the technical solution of the present invention solves the technical problems and the creative technical effects brought after solving the problems. The specific description is as follows:

[0023] The present invention maximally utilizes the energy-saving effect generated by siphon while solving the harm caused by the vacuum generated by siphon to production.

[0024] Second, as the creative auxiliary evidence of the claims of the present invention, it is also reflected in the following important aspects:

[0025] (1) The expected benefits and commercial value after the transformation of the technical solution of the present invention are as follows: There are a large number of tower-type equipment in the circulating water system of chemical plants nowadays. Almost all of them are working by forming positive pressure at the top (the most unfavorable point). For some key major production equipment, this is still necessary, but for some non-key equipment, it can completely operate at reduced pressure according to the method disclosed in the present invention. Judging from the inventor's many years of experience in implementing energy-saving projects, for chemical enterprises, after implementing the pressure reduction, the average power saving rate of the circulating water system will reach 10%. The power saving cost of the projects that can be modified nationwide will reach more than 100 million yuan.

[0026] (2) The technical solution of the present invention fills the technical gaps in the domestic and international industries:

[0027] There is no introduction to this method at home and abroad at present, and the present invention is proposed for the first time.

[0028] (3) The technical solution of the present invention overcomes the technical prejudice:

[0029] The necessary conditions for the utilization of siphon proposed by the present invention are actually the necessary safety production conditions that must be maintained at every point in the entire pipeline design process of the circulating water system. The previous design methods generally relied on the empirical formulas introduced in the design manuals, without specific expressions of the necessary conditions. The present invention proposes a specific calculation method here. Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of an energy-saving device that utilizes the siphon ability of the pipe network provided by an embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the highest temperature position for measuring the cold fluid side provided by an embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of a convex shape in the water supply system provided by an embodiment of the present invention;

[0033] In the figure: 1, water supply pipeline; 2, circulating water inlet pipe; 3, circulating water outlet pipe; 4, regulating valve; 5, top water outlet pipeline; 6, water level gauge; 7, water level tank; 8, connecting pipe. Detailed Embodiment

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the following further elaborates on the present invention in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] This part is an explanatory embodiment that expands and explains the technical solution of the claims in order to enable those skilled in the art to fully understand how the present invention is specifically implemented.

[0036] Such as Figure 1As shown in the figure, in the energy-saving device that utilizes the siphonage capacity of the pipe network provided by the embodiments of the present invention, a water level tank 7 is installed at the top of a tower-type device or a water supply pipe 1. The top and bottom of the water level tank 7 are respectively connected to the downward pipeline in the water flow direction at the top of the water supply pipe 1 through a communication pipe 8. A water level gauge 6 or a water level sensor is installed on the water level tank 7. The highest point at the top of the water supply pipe 1 is connected to a vacuum pump through a top water outlet pipe 5. The water supply pipe 1 is connected with a circulating water inlet pipe 2 and a circulating water outlet pipe 3, and the circulating water outlet pipe 3 is connected with a regulating valve 4. In order to ensure that when the top is in a vacuum state, the gas brought by the circulating water can continue to be discharged, and at the same time, the water vapor vaporized during the adjustment process can be avoided, the highest point of the water supply pipe 1 is connected to the vacuum pump through the top water outlet pipe 5. When it is measured that the water level in the water level tank 7 drops, the vacuum pump is connected to pump air; at the same time, the regulating valve is adjusted. When the water level reaches the same height as the top of the water pipe, the connection with the vacuum pump is closed.

[0037] As Figure 2 shown, the necessary conditions for siphon utilization are proposed: To utilize siphonage, it is necessary to ensure that the entire control system to be controlled is airtight, that is, it is not connected to the outside and there is no material exchange. The pressure at the highest point must be ensured that it will not vaporize. The reason why the circulating water supply needs to be sent to a high place is that cooling or other necessary water supply is required at a high place. And water has different vaporization pressures at different temperatures. When the actual pressure of water is lower than the vaporization pressure, it will vaporize. Vaporization will turn water into steam, losing the cooling effect, and gas blockage will also occur, resulting in a break in the flow. The vaporization of water is related to temperature, and the vaporization pressure is different at different temperatures. Therefore, the necessary pressure at the highest point needs to be calculated in advance. For non-heat-transfer pipes, only by looking up the manual through the temperature of water can the saturation pressure of water be known, and the saturation pressure is the vaporization pressure. For pipes used for heat transfer, it is necessary to measure or calculate the temperature of the heat transfer pipe wall, and determine the vaporization pressure according to the highest temperature generated locally when water contacts the pipe wall. For complex systems, the specific position of the highest temperature should be calculated through relevant theories of heat transfer, or calculated using a thermal simulation tool.

[0038] The working principle of the present invention is as follows: If vaporization occurs, it will surely accumulate at the top of the pipeline. Since the water level tank is connected to the top of the pipeline, when there is vapor at the top, the water level in the water level tank 7 will drop. When the system detects the drop in water level through the water level gauge 6 or the sensor, the regulating valve 4 should be gradually closed until the water level in the water level tank 7 basically stops dropping. At this time, the top pressure is the most energy-saving. After the valve in the regulating valve 4 is adjusted, the pipeline leading to the vacuum system is connected to discharge the air and the remaining steam at the top; even if air is introduced and a small amount of vaporization occurs, it can be discharged in time. The suction of the vacuum pump and the closing of the regulating valve 4 will both produce external characteristics that reduce the influence of vaporization at the top of the pipeline. However, when the valve in the regulating valve 4 is closed, the vacuum suction frequency will decrease. Due to the air brought in by the water, it is impossible for the vacuum pump not to suck at all; in practice, a satisfactory pumping frequency can be adjusted according to different equipment and the gas content of the medium. To solve the problem of different pressure requirements during startup and normal operation, the water supply equipment only needs to meet the pressure requirements after siphon startup. When the system starts up, start the water supply equipment and close the regulating valve 4; at the same time, start the vacuum pump to suck the inside of the pipeline until the water level in the water level tank 7 is equal to the top of the pipeline, open the regulating valve 4, and disconnect the vacuum pump after opening the valve in the regulating valve 4, and the startup is completed. Regarding the vacuum system, it is not necessary to keep the vacuum pump running continuously to enable suction at any time when the system needs it, because the energy consumption of such a vacuum system is too high. A vacuum maintenance system can be used, but the specific structure is not described in the present invention.

[0039] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. An energy-saving device utilizing the siphon capacity of a pipe network, characterized in that, The energy-saving device using the siphon capacity of the pipe network is provided with: A water level tank; The top of the water level tank is connected to the top of the water supply pipe through a connecting pipe, and the lower part of the water level tank is connected to the water supply pipe with a descending water flow direction through a connecting pipe. A water level measuring device is installed on the water level tank; An energy-saving method using the siphon capacity of the pipe network of the energy-saving device using the siphon capacity of the pipe network. The energy-saving method using the siphon capacity of the pipe network includes: When vaporization occurs and accumulates at the top of the pipe, and the water level tank is connected to the top of the pipe and there is steam at the top of the pipe, the water level of the water level tank drops; when the system detects the drop in water level through a water level gauge or sensor, the regulating valve is adjusted until the water level of the water level tank remains unchanged and the pressure at the top of the pipe is in the most energy-saving state; After the valve in the regulating valve is adjusted, the pipe leading to the vacuum system is connected to discharge the air and remaining steam at the top; the suction of the vacuum pump and the closing of the regulating valve both produce external characteristics that reduce the influence of vaporization at the top of the pipe; by adjusting the regulating valve and the vacuum pump, the different pressure requirements during startup and normal operation are solved; The specific process of adjusting the regulating valve until the water level of the water level tank remains unchanged when the system detects the drop in water level through a water level gauge or sensor is as follows: When the system detects the drop in water level through a water level gauge or sensor, the regulating valve is gradually adjusted smaller until the water level of the water level tank remains unchanged and the top pressure is the most energy-saving.

2. The energy-saving device using the siphon capacity of the pipe network according to claim 1, wherein The water level tank is installed at the top of tower equipment or the water supply pipe.

3. The energy-saving device using the siphon capacity of the pipe network according to claim 2, characterized in that, The highest point of the top of the water supply pipe is connected to the vacuum pump through a top water outlet pipe.

4. The energy-saving device using the siphon capacity of the pipe network according to claim 2, characterized in that, The water supply pipe is connected with a circulating water inlet pipe and a circulating water outlet pipe.

5. The energy-saving device using the siphon capacity of the pipe network according to claim 4, characterized in that, The circulating water outlet pipe is connected to the regulating valve.

6. The energy-saving device using the siphon capacity of the pipe network according to claim 1, wherein, The water level measuring device is a water level gauge or a water level sensor.

7. The energy-saving device using the siphon capacity of the pipe network according to claim 1, characterized in that, The specific process of the external characteristics that the suction of the vacuum pump and the closing of the regulating valve both produce to reduce the influence of vaporization at the top of the pipe is as follows: When the valve in the regulating valve is adjusted smaller, the frequency of vacuum suction decreases; due to water bringing in air, the vacuum pump sucks; in practice, according to different equipment and the gas content of the medium, the appropriate pumping frequency is adjusted.

8. The energy-saving device using the siphon capacity of the pipe network according to claim 1, characterized in that, The specific process of solving the different pressure requirements during startup and normal operation by adjusting the regulating valve is as follows: The water supply equipment meets the pressure requirements after siphon startup. When the system starts, the water supply equipment is started and the regulating valve is closed; at the same time, the vacuum pump is started to suck the inside of the pipe until the water level of the water level tank is equal to the top of the pipe, the regulating valve is opened, the valve in the regulating valve is started and then the vacuum pump is disconnected, and the startup ends.

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