CN114623650B - Fine control method for cooling water flow - Google Patents
Fine control method for cooling water flow Download PDFInfo
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- CN114623650B CN114623650B CN202210531788.3A CN202210531788A CN114623650B CN 114623650 B CN114623650 B CN 114623650B CN 202210531788 A CN202210531788 A CN 202210531788A CN 114623650 B CN114623650 B CN 114623650B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D17/00—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces
- F25D17/02—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating liquids, e.g. brine
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D29/00—Arrangement or mounting of control or safety devices
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
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- Engineering & Computer Science (AREA)
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- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
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- General Engineering & Computer Science (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention belongs to the technical field of high-speed wind tunnel test equipment, and discloses a fine control method for cooling water flow. The fine control method is used for a fine control system, a plurality of pumps I and II which are connected in parallel are communicated with a water pool through pipelines, and each pump is driven by a corresponding variable frequency motor; the pump I and the pump II respectively pump cooling water from the water pool and converge into a path of cooling water to be sent to the heat exchange equipment for heat exchange, and hot water after heat exchange is cooled by a plurality of cooling towers connected in parallel and flows into the water pool; the heat exchange equipment is provided with a flow regulating valve connected in parallel as a bypass. The cooling water flow of the pump I is larger than that of the pump II; the sum of the flow rates of the cooling water pumped by the pumps I and II is more than or equal to the maximum flow rate of the cooling water pumped by the heat exchange equipment. The fine control method adopts three-level regulation modes of coarse regulation, medium regulation and fine regulation, meets the maximum heat exchange requirement of the heat exchange equipment, realizes fine control and regulation of the flow rate of the cooling water, and has high popularization value.
Description
Technical Field
The invention belongs to the technical field of high-speed wind tunnel test equipment, and particularly relates to a fine control method of cooling water flow.
Background
A certain continuous wind tunnel is a backflow wind tunnel and mainly comprises a compressor, a tunnel body structure, a measurement and control system, a heat exchange system, a circulating water system and the like. The heat energy generated by the compressor acting on the air can cause the air temperature in the wind tunnel to continuously rise, and the air in the tunnel needs to be continuously cooled through the heat exchange system and the circulating water system, so that the safety of equipment is ensured.
Meanwhile, the air temperature is an important parameter influencing wind tunnel test data. Therefore, the normal operation of the wind tunnel requires that the circulating water system not only have very strong cooling capacity, but also have very fine flow regulation capacity. The problems to be solved are as follows: firstly, through reasonable pump set design, the cooling water quantity is ensured to meet the maximum heat exchange requirement of the wind tunnel, and the safety of equipment and instruments is ensured; secondly, the flow rate is finely adjusted by scientific design and multi-stage adjustment of a circulating water loop, and the fluctuation value of the air temperature is ensured to be within the allowable range (plus or minus 0.5 ℃).
Currently, there is a need to develop a fine control method that can be used in a continuous wind tunnel and can finely control the flow rate of cooling water.
Disclosure of Invention
The invention aims to provide a method for finely controlling the flow of cooling water.
The fine control method of the cooling water flow is characterized in that the fine control method is used for a fine control system, and the fine control system comprises a cooling tower, a water pool, a pump I variable frequency motor, a pump I, a pump II variable frequency motor, a pump II, a flow regulating valve, heat exchange equipment, an auxiliary pipeline and a stop valve;
a plurality of pumps I and II which are connected in parallel are communicated with a water pool through pipelines, each pump I is driven by a corresponding pump I variable frequency motor, and each pump II is driven by a corresponding pump II variable frequency motor; the pump I and the pump II respectively pump cooling water from the water pool and converge into a path of cooling water to be sent to the heat exchange equipment for heat exchange, and hot water after heat exchange is cooled by a plurality of cooling towers connected in parallel and flows into the water pool; meanwhile, the heat exchange equipment is provided with a flow regulating valve connected in parallel as a bypass;
the cooling water flow of the pump I is larger than that of the pump II; the sum of the flow of the cooling water pumped by each pump I and the flow of the cooling water pumped by each pump II is more than or equal to the maximum flow of the cooling water required by the heat exchange equipment.
The fine control method comprises the following steps:
s10, roughly adjusting the amount of cooling water;
counting all start-stop combination modes of a plurality of pumps I and II connected in parallel, determining a start-stop combination mode which is larger than and closest to cooling water flow required by heat exchange equipment as a selected mode, and opening the corresponding pump I and pump II according to the selected mode;
s20, adjusting the quantity of cooling water;
respectively adjusting the rotating speed of a pump I variable frequency motor of each driving pump I and the rotating speed of a pump II variable frequency motor of each driving pump II in a selected mode, so that the sum of the cooling water flow of each branch is larger than and more close to the cooling water flow required by heat exchange equipment; wherein, the adjusting ranges of the variable frequency motor of the pump I and the variable frequency motor of the pump II are both 25 Hz-50 Hz, and the adjustment is carried out by taking 1 Hz-2 Hz as a first gear;
s30, finely adjusting the amount of cooling water;
opening a flow regulating valve, and shunting cooling water flow from the sum of the cooling water flow of each branch so that the sum of the cooling water flow flowing into the heat exchange equipment is closer to the cooling water flow required by the heat exchange equipment;
s40, repeating the steps S20-S30, and continuously reducing the cooling water flow of the flow regulating valve until the regulating differential quantity of the flow regulating valve in the two times reaches the control precision of the flow regulating valve, so as to finish regulation.
The fine control method for the flow of the cooling water can reduce the flow passing through the flow regulating valve as much as possible on the premise of meeting the fine regulation of the flow of the heat exchange equipment, thereby realizing the energy-saving requirement.
The fine control method for the cooling water flow adopts three-level regulation modes of coarse regulation, medium regulation and fine regulation, can realize fine control and regulation of the cooling water flow while meeting the maximum heat exchange requirement of heat exchange equipment of a certain continuous wind tunnel, and meets the requirement of air temperature cooling and control of the continuous wind tunnel.
The fine control method of the cooling water flow is suitable for fine control and graded adjustment of the cooling water flow under large-flow and wide-industry-area conditions, has strong popularization value, and can provide reference and reference for similar large-scale cooling water system design.
Drawings
Fig. 1 is a schematic structural diagram of a fine control system used in the fine control method for the flow rate of cooling water according to the present invention.
In the figure, 1. cooling tower; 2. a pool; 3. a pump I variable frequency motor; 4, a pump I; 5. a variable frequency motor of the pump II; 6. a pump II; 7. a flow regulating valve; 8. and (4) heat exchange equipment.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and examples.
Example 1
The fine control system of this embodiment calculates the sum of cooling water flow according to the heat transfer demand of indirect heating equipment 8, needs to dispose 2 pumps I4 and 2 pumps II 6.
As shown in fig. 1, the fine control system used in the fine control method of the present embodiment includes 3 cooling towers 1, 1 water tank 2, 2 pump i variable frequency motors 3, 2 pump i 4, 2 pump ii variable frequency motors 5, 2 pumps ii 6, 1 flow regulating valve 7, 1 heat exchange device 8, and an attached pipeline and a stop valve;
the water pool 2 is a public water storage pool, each pump I4 is driven by a corresponding pump I variable frequency motor 3, each pump II 6 is driven by a corresponding pump II variable frequency motor 5, cooling water in the water pool 2 is sucked out by the pump I4 and the pump II 6 and flows into a loop, the flow regulating valve 7 is arranged in parallel with the heat exchange device 8, bypass short flow of the cooling water is achieved within a certain range, the cooling water passes through the heat exchange device 8 or the flow regulating valve 7, hot water after heat exchange flows to the cooling tower 1 and flows back to the water pool 2 after cooling, and the hot water is sucked out again by the pump I4 and the pump II 6 and recycled.
The fine control method of the embodiment includes three adjustment modes of coarse adjustment, medium adjustment and fine adjustment.
The first stage is coarse adjustment: the main method is characterized in that the combined modes of a pump I4 and a pump II 6 are listed by controlling the number of starting and stopping the pump, the specific combined modes comprise eight types, namely a 2 pump I4 +2 pump II 6, a 2 pump I4 +1 pump II 6, a 1 pump I4 +2 pump II 6, a 2 pump I4, a 1 pump I4 +1 pump II 6, a 2 pump II 6, a 1 pump I4 and a 1 pump II 6, and the approximate regulation of the flow demand of the heat exchange equipment 8 under all working conditions can be realized; determining a starting and stopping combined mode which is larger than and closest to the cooling water flow required by the heat exchange equipment 8 from the combined modes as a selected mode, and opening the corresponding pump I4 and pump II 6 according to the selected mode;
the second level is middle adjustment: on the basis of rough adjustment, the rotating speed of a pump I variable frequency motor 3 of each driving pump I4 and the rotating speed of a pump II variable frequency motor 5 of each driving pump II 6 in a selected mode are respectively adjusted, so that the sum of the cooling water flow of each branch is larger than and closer to the cooling water flow required by the heat exchange equipment 8; wherein, the adjusting ranges of the variable frequency motor 3 of the pump I and the variable frequency motor 5 of the pump II are both 25Hz to 50Hz, and the adjustment is carried out by taking 1Hz to 2Hz as a first gear;
the third stage is fine tuning: under the condition that the coarse adjustment and the middle adjustment cannot be accurately matched with the heat exchange requirements, the sum of the flow of the cooling water flowing into the heat exchange equipment 8 is closer to the flow of the cooling water required by the heat exchange equipment 8 through the bypass short flow of the flow regulating valve 7;
finally, the cooling water flow is continuously finely adjusted by repeating the intermediate adjustment and the fine adjustment, the fine adjustment of the cooling water flow is realized by the control precision of the flow regulating valve 7, the environmental protection is realized to the maximum extent, and the waste of cooling water resources is avoided.
Although the embodiments of the present invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, but it can be applied to various fields suitable for the present invention. Additional modifications and refinements will readily occur to those skilled in the art without departing from the principles of the present invention, and the present invention is not limited to the specific details and illustrations shown and described herein.
Claims (1)
1. The fine control method of the cooling water flow is characterized in that the fine control method is used for a fine control system, and the fine control system comprises a cooling tower (1), a water tank (2), a pump I variable frequency motor (3), a pump I (4), a pump II variable frequency motor (5), a pump II (6), a flow regulating valve (7), heat exchange equipment (8), an auxiliary pipeline and a stop valve;
a plurality of pumps I (4) and II (6) which are connected in parallel are communicated with the water pool (2) through pipelines, each pump I (4) is driven by a corresponding pump I variable frequency motor (3), and each pump II (6) is driven by a corresponding pump II variable frequency motor (5); the pump I (4) and the pump II (6) respectively pump cooling water from the water pool (2) and converge into a path of cooling water to be sent to the heat exchange equipment (8) for heat exchange, and hot water after heat exchange flows into the water pool (2) after being cooled by a plurality of cooling towers (1) which are connected in parallel; meanwhile, the heat exchange equipment (8) is provided with a flow regulating valve (7) connected in parallel as a bypass;
the cooling water flow of the pump I (4) is larger than that of the pump II (6); the sum of the cooling water flow rate pumped by each pump I (4) and each pump II (6) is more than or equal to the maximum cooling water flow rate required by the heat exchange equipment (8);
the fine control method comprises the following steps:
s10, roughly adjusting the amount of cooling water;
counting all start-stop combination modes of a plurality of pumps I (4) and II (6) which are connected in parallel, determining a start-stop combination mode which is larger than and closest to cooling water flow required by the heat exchange equipment (8) as a selected mode, and opening the corresponding pump I (4) and the pump II (6) according to the selected mode;
s20, adjusting the quantity of cooling water;
respectively adjusting the rotating speed of a pump I variable frequency motor (3) of each driving pump I (4) and the rotating speed of a pump II variable frequency motor (5) of each driving pump II (6) in a selected mode, so that the sum of the cooling water flow of each branch is larger than and closer to the cooling water flow required by the heat exchange equipment (8); the adjusting ranges of the variable frequency motor (3) of the pump I and the variable frequency motor (5) of the pump II are both 25 Hz-50 Hz, and the adjustment is carried out in a mode of 1 Hz-2 Hz;
s30, finely adjusting the amount of cooling water;
opening a flow regulating valve (7), and dividing the flow of cooling water from the sum of the flow of cooling water of each branch so that the sum of the flow of cooling water flowing into the heat exchange equipment (8) is closer to the flow of cooling water required by the heat exchange equipment (8);
s40, repeating the steps S20-S30, and continuously reducing the cooling water flow of the flow regulating valve (7) until the adjustment difference of the flow regulating valve (7) in the two times reaches the control precision of the flow regulating valve (7), so as to finish the adjustment.
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| CN202210531788.3A CN114623650B (en) | 2022-05-17 | 2022-05-17 | Fine control method for cooling water flow |
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| CN202210531788.3A CN114623650B (en) | 2022-05-17 | 2022-05-17 | Fine control method for cooling water flow |
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| CN114623650B true CN114623650B (en) | 2022-08-09 |
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| CN118226908B (en) * | 2024-05-27 | 2024-07-30 | 中国空气动力研究与发展中心高速空气动力研究所 | Wind tunnel total temperature control device and method for solving quick response problem of large hysteresis system |
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