CN-121977270-A - Water storage tank liquid level balance regulation and control system and method for chilled water storage air conditioning system

CN121977270ACN 121977270 ACN121977270 ACN 121977270ACN-121977270-A

Abstract

The invention relates to a water storage tank liquid level balance regulation system and method of a water storage air conditioning system, wherein the method comprises the steps of determining a target cold storage tank to be regulated and a liquid level height difference predicted value change curve along with valve opening according to a topological structure of a pipe network and hydraulic parameters of a pipe, and determining a target valve to be regulated according to characteristics of the change curve and the target cold storage tank; and determining a fine adjustment direction according to the positive and negative of the real-time liquid level difference in the first cold accumulation tank and the second cold accumulation tank, and fine adjusting the target valve according to a preset adjustment gradient until the real-time liquid level difference reaches a preset liquid level deviation range. The liquid level difference between different cold accumulation tanks is maintained in the allowable deviation range through the coarse adjustment and fine adjustment processes, the system has simple structure, the operation is stable and reliable, the cost is low, the problem of liquid level difference among different cold accumulation tanks can be solved, and overflow is prevented.

Inventors

XU XINHUA
FANG YUHAO
TANG LIKUAN
SHU XINGYU
DENG JIEWEN
ZHANG YUAN

Assignees

华中科技大学
嘉立坤(广州)自动化科技有限责任公司

Dates

Publication Date: 20260505
Application Date: 20260120

Claims (10)

1. The water storage tank liquid level balance regulation and control system for the water cold storage air conditioning system is applied to heat exchange of a user terminal and is characterized by comprising a refrigerating unit (1), a first cold storage tank (2), a second cold storage tank (3), a chilled water return pipe (8), a chilled water supply pipe (9), a chilled water pump (7), a cold storage pump (5), a chilled water supply pipe (6), a controller (4) and a valve assembly, wherein the chilled water return pipe (8), the chilled water pump (7), the refrigerating unit (1), the chilled water supply pipe (9) and the user terminal are sequentially communicated and form a circulating water loop, the chilled water return pipe (8), the first cold storage tank (2), the chilled water supply pipe (6), the chilled water supply pipe (9) and the user terminal are sequentially communicated and form a first cold release loop, the chilled water return pipe (8), the second cold storage tank (3), the chilled water supply pipe (6), the chilled water supply pipe (9) and the user terminal are sequentially communicated and form a second cold release loop, the first cold storage pump (5) and the refrigerating unit (1) are sequentially communicated and form a first cold release loop, the second cold storage pump (1), the cold storage pump (5) and the cold storage tank (1) are sequentially communicated and the cold storage tank (5) and the user terminal are sequentially communicated The cooling pump (6) and the valve component are respectively and electrically connected with the controller (4); The refrigerating unit (1) is respectively provided with the cold accumulation pump (5) on a common pipeline between the first cold accumulation tank (2) and the second cold accumulation tank (3), a cold discharge pump (6) is arranged on a common pipeline between the refrigerating unit (1) and the first cold accumulation tank (2) and the second cold accumulation tank (3) respectively, a chilled water pump (7) is arranged on a pipeline between a chilled water return pipe (8) and the refrigerating unit (1), the chilled water return pipe (8) is respectively provided with a pipeline between the first cold accumulation tank (2) and the second cold accumulation tank (3) respectively, the chilled water supply pipe (9) is respectively provided with a pipeline between the first cold accumulation tank (2) and the second cold accumulation tank (3) respectively, a pipeline between the refrigerating unit (1) and the first cold accumulation tank (2) and the second cold accumulation tank (3), a pipeline between the chilled water return pipe (8) and the refrigerating unit (1) and a water supply pipe (9) and a liquid level meter (1-2) is respectively arranged in the refrigerating unit (1) and a second cold accumulation tank (3), the device is used for respectively collecting the real-time liquid level heights in the first cold accumulation tank (2) and the second cold accumulation tank (3); the controller (4) is used for determining a target cold accumulation tank to be regulated according to the topological structure of the pipe network and the hydraulic parameters of the pipeline; The controller (4) is used for determining a liquid level height difference predicted value changing curve along with the valve opening according to the topological structure of the pipe network and the pipeline hydraulic parameter, and determining a target valve to be regulated according to the characteristic of the liquid level height difference predicted value changing curve along with the valve opening and the target cold accumulation tank; the controller (4) is used for roughly adjusting the opening of the target valve according to the zero position of the liquid level height difference predicted value along with the valve opening change curve; the controller (4) is used for determining a fine adjustment direction according to the positive and negative of the real-time liquid level difference in the first cold accumulation tank (2) and the second cold accumulation tank (3), and fine adjusting the target valve according to a preset adjustment gradient until the real-time liquid level difference in the first cold accumulation tank (2) and the second cold accumulation tank (3) reaches a preset liquid level deviation range.
2. The water storage tank liquid level balance regulation system of the chilled water storage air conditioning system according to claim 1, wherein: the system is characterized in that one end of a chilled water return pipe (8) far away from a user terminal is communicated with one end of a cold and hot end pipe section branch pipe, the other end of the cold and hot end pipe section branch pipe is respectively communicated with hot end pipe sections of a first cold storage tank (2) and a second cold storage tank (3), the other end of the cold and hot end pipe section branch pipe is also communicated with one end of the cold and hot end pipe section branch pipe, the other end of the cold and hot end pipe section branch pipe is also communicated with a return water port of a refrigeration host (1), a refrigeration host return water pipe is communicated between one end of the chilled water return pipe (8) far away from the user terminal and the return water port of the refrigeration host (1), one end of a chilled water supply pipe (9) far away from the user terminal is communicated with one end of a cold end pipe section branch pipe of a cold storage tank, the other end of the cold end branch pipe section branch pipe is respectively communicated with cold end pipe sections of the first cold storage tank (2) and the second cold storage tank (3), the other end of the cold end pipe section branch pipe is also communicated with one end of the cold end pipe section branch pipe of the cold storage pipe section, the other end of the cold end pipe section branch pipe is also communicated with the return water port of the refrigeration host (1), one end of the cold end pipe branch pipe is also communicated with a return water port of the refrigeration host (1), and one end of the water supply pipe (9) far away from the user terminal is communicated with a return water supply port of the refrigeration host (1; the cold accumulation pump (5) is arranged on the cold accumulation hot end pipe section branch pipe, the cold discharge pump (6) is arranged on the cold discharge cold end pipe section branch pipe, and the chilled water pump (7) is arranged on the refrigerating host water return pipe.
3. The water storage tank liquid level balance regulation and control system of the chilled water storage air conditioning system according to claim 2, wherein the valve assembly comprises a first hot end valve (2-2), a second hot end valve (3-2), a first cold end valve (2-3) and a second cold end valve (3-3), the first hot end valve (2-2) and the second hot end valve (3-2) are respectively arranged on hot end pipe sections of the first cold storage tank (2) and the second cold storage tank (3), and the first cold end valve (2-3) and the second cold end valve (3-3) are respectively arranged on cold end pipe sections of the first cold storage tank (2) and the second cold storage tank (3); The valve assembly further comprises a third valve (10), a fourth valve (11), a fifth valve (12), a sixth valve (13), a seventh valve (14) and an eighth valve (15), wherein the third valve (10) is arranged on a cold-storage cold-end pipe section branch pipe, the fourth valve (11) is arranged on the cold-storage cold-end pipe section branch pipe, the fifth valve (12) is arranged on a water supply pipe of a refrigeration host, the sixth valve (13) is arranged on a water return pipe of the refrigeration host, the seventh valve (14) is arranged on the cold-storage hot-end pipe section branch pipe, and the eighth valve (15) is arranged on the cold-storage cold-end pipe section branch pipe.
4. The water cold-storage air conditioning system water storage tank liquid level balance regulation and control system according to claim 2 is characterized by further comprising a differential pressure sensor, wherein a cold end tee joint (16) is arranged at the joint of the other end of the cold end pipe section branch pipe of the cold-storage cold-end pipe section and the cold end pipe sections of the first cold-storage tank (2) and the second cold-storage tank (3), a hot end tee joint (17) is arranged at the joint of the other end of the cold end pipe section branch pipe of the cold-storage cold-end pipe section and the hot end pipe section of the first cold-storage tank (2) and the hot end pipe section of the second cold-storage tank (3), the differential pressure sensor is arranged at the cold end tee joint (16) and the hot end tee joint (17), and the controller calculates the differential pressure between the cold end tee joint and the hot end tee joint (17) according to the pressure acquired by the differential pressure sensor.
5. A method for regulating and controlling the liquid level balance of a water storage tank of a chilled water storage air conditioning system, which is characterized by adopting the water storage tank liquid level balance regulating and controlling system of the chilled water storage air conditioning system according to any one of claims 1-4, comprising the following steps: determining a target cold accumulation tank to be regulated according to the topological structure of the pipe network and the hydraulic parameters of the pipe; Determining a liquid level height difference predicted value changing curve along with the valve opening according to the topological structure of a pipe network and pipeline hydraulic parameters, and determining a target valve to be regulated according to the characteristic of the liquid level height difference predicted value changing curve along with the valve opening and the target cold accumulation tank; coarse-adjusting the opening of the target valve according to the zero position of the valve opening change curve along with the liquid level height difference predicted value; Determining a fine adjustment direction according to the positive and negative of the real-time liquid level difference in the first cold accumulation tank (2) and the second cold accumulation tank (3), and fine adjusting the target valve according to a preset adjustment gradient until the real-time liquid level difference in the first cold accumulation tank (2) and the second cold accumulation tank (3) reaches a preset liquid level deviation range.
6. The method for regulating and controlling the liquid level balance of a water storage tank of a chilled water storage air conditioning system according to claim 5, wherein the determining the target chilled water storage tank to be regulated according to the topological structure of a pipe network and the hydraulic parameters of a pipe comprises the following steps: Respectively calculating the resistance coefficient and the resistance coefficient of the hot end pipe section of the first cold accumulation tank (2) according to the topological structure of the pipe network and the hydraulic parameters of the pipe Coefficient of resistance of cold end pipe section And the resistance coefficient of the hot end pipe section of the second cold accumulation tank (3) Coefficient of resistance of cold end pipe section The calculation formula is as follows: ; ; ; ; Wherein, the 、 Respectively the local resistance coefficients of the hot end pipe section and the cold end pipe section of the first cold storage tank (2), 、 Respectively the local resistance coefficients of the hot end pipe section and the cold end pipe section of the second cold storage tank (3), And The coefficients of resistance along the way of the first cold accumulation tank (2) and the second cold accumulation tank (3) are respectively, 、 The lengths of a hot end pipe section and a cold end pipe section of the first cold accumulation tank (2) are respectively, 、 The lengths of a hot end pipe section and a cold end pipe section of the second cold accumulation tank (3) are respectively, 、 The pipe diameters of the first cold accumulation tank (2) and the second cold accumulation tank (3) are respectively; According to the resistance coefficient and the resistance coefficient of the hot end pipe section of the first cold accumulation tank (2) Coefficient of resistance to cold end pipe section Sum of the resistance coefficient of the hot end pipe section of the second cold accumulation tank (3) Coefficient of resistance to cold end pipe section The sum of which determines the target cold accumulation tank to be regulated.
7. The method for regulating and controlling the liquid level balance of a water storage tank of a chilled water storage air conditioning system according to claim 6, wherein the resistance coefficient and the resistance coefficient of a hot end pipe section of the first chilled water storage tank (2) are calculated Coefficient of resistance to cold end pipe section Sum of the resistance coefficient of the hot end pipe section of the second cold accumulation tank (3) Coefficient of resistance to cold end pipe section The target cold accumulation tank for determining the sum of the two values to be regulated specifically comprises the following steps: If it is Determining the first cold accumulation tank (2) as a target cold accumulation tank needing to be regulated, if And determining the second cold accumulation tank (3) as a target cold accumulation tank needing to be adjusted.
8. The method for regulating and controlling the liquid level balance of a water storage tank of a chilled water storage air conditioning system according to claim 5, wherein the determining a liquid level difference predicted value along with a valve opening change curve according to a topological structure of a pipe network and a pipeline hydraulic parameter, and determining a target valve to be regulated according to the characteristic of the liquid level difference predicted value along with the valve opening change curve and the target chilled water storage tank specifically comprises the following steps: Determining a change curve of a liquid level difference predicted value of a first cold accumulation tank (2) and a second cold accumulation tank (3) along with the opening degrees of a first hot end valve (2-2), a first cold end valve (2-3), a second hot end valve (3-2) and a second cold end valve (3-3) according to a topological structure of a pipe network and pipeline hydraulic parameters, wherein the calculation formula is as follows: The cold accumulation working condition is as follows: ; ; ; ; under the cooling working condition: ; ; ; ; Wherein, the 、、、 Respectively adjusting liquid level height difference predicted values of the first cold accumulation tank (2) and the second cold accumulation tank (3) corresponding to the first hot end valve (2-2), the first cold end valve (2-3), the second hot end valve (3-2) and the second cold end valve (3-3) under the cold accumulation working condition, 、、、 The liquid level height difference predicted values of the first cold accumulation tank (2) and the second cold accumulation tank (3) corresponding to the opening degrees of the first hot end valve (2-2), the first cold end valve (2-3), the second hot end valve (3-2) and the second cold end valve (3-3) under the cold release working condition are respectively, y is the opening degree of the valve, the value range is 0-90 degrees, 、 Respectively the resistance coefficients of the hot end pipe section and the cold end pipe section of the first cold accumulation tank (2), 、 Respectively the resistance coefficients of the hot end pipe section and the cold end pipe section of the second cold storage tank (3), Is the resistance coefficient of the first hot end valve (2-2) along with the change of the opening, Is the resistance coefficient of the second hot end valve (3-2) which changes along with the opening, The resistance coefficient is the resistance coefficient when the valve is fully opened; For the pressure difference between the tee joint of the cold end and the hot end under the design working condition, the calculation formula is as follows: , In order to design the lift of the water pump under the working condition, In the first cold accumulation loop, the second cold accumulation loop, the first cold release loop or the second cold release loop, except the total impedance of the pipelines of the cold accumulation tank branch part, In order to achieve the density of water, A gravitational constant; Under different working conditions, aiming at a target cold accumulation tank, selecting a valve corresponding to a zero-crossing change curve in a change curve of a liquid level height difference predicted value along with the opening of a first hot end valve (2-2) and a first cold end valve (2-3), or selecting a valve corresponding to a zero-crossing change curve in a change curve of a liquid level height difference predicted value along with the opening of a second hot end valve (3-2) and a second cold end valve (3-3) as a target valve to be regulated.
9. The method for regulating and controlling the liquid level balance of a water storage tank of a chilled water storage air conditioning system according to claim 5, wherein the coarse adjustment of the opening of the target valve according to the zero position of the predicted value of the liquid level height difference along with the change curve of the opening of the valve specifically comprises the following steps: And carrying out rough adjustment on the opening of the target valve according to the valve opening corresponding to the zero position on the valve opening variation curve of the liquid level difference predicted value, so that the opening of the target valve is positioned in a valve opening range corresponding to a preset liquid level height deviation range taking the zero point as the center on the valve opening variation curve of the liquid level difference predicted value.
10. The method for regulating and controlling the liquid level balance of a water storage tank of a chilled water storage air conditioning system according to any one of claims 5 to 9, wherein the determining a fine adjustment direction according to the positive and negative of the real-time liquid level difference in the first and second chilled water storage tanks (2, 3) and fine adjusting the target valve according to a preset adjustment gradient until the real-time liquid level difference in the first and second chilled water storage tanks (2, 3) reaches a preset liquid level deviation range specifically comprises the following steps: Acquiring real-time liquid level heights in the first cold accumulation tank (2) and the second cold accumulation tank (3), and calculating a real-time liquid level height difference delta H in the first cold accumulation tank (2) and the second cold accumulation tank (3); if delta H >0, regulating the target valve along the direction that the predicted value of the liquid level height difference is gradually decreased along with the valve opening change curve, regulating the gradient to delta y, and performing cyclic iteration until the real-time liquid level height difference delta H reaches a preset liquid level deviation range; If delta H is less than 0, regulating the target valve along the direction that the predicted value of the liquid level height difference increases along with the valve opening change curve, regulating the gradient to delta y, and performing cyclic iteration until the real-time liquid level height difference delta H reaches the preset liquid level deviation range.

Description

Water storage tank liquid level balance regulation and control system and method for chilled water storage air conditioning system Technical Field The invention relates to the technical field of air conditioner control, in particular to a liquid level balance regulating and controlling system and method for a cold storage tank of a chilled water storage air conditioning system. Background The central air conditioner has wide application, and the energy consumption of the central air conditioner accounts for about 40% of the total energy consumption of public buildings. Many cities can be air conditioned up to 50% of peak local grid loads. Therefore, the energy-saving research in the air conditioner field becomes a very important part of energy-saving work in China, and the air conditioner energy-saving research has great significance on energy conservation. In recent years, an advanced novel central air conditioning system, namely a cold accumulation air conditioning system, is applied to practical engineering practice. The chilled water storage air conditioning system is widely applied to various projects, particularly industrial buildings, due to good economic benefits. The water cold storage technology utilizes night valley electricity period, uses a conventional refrigerating unit to prepare cold water, stores the cold water in a water tank, uses electricity peak period in the daytime the next day, and uses the stored cold water to supply cold for users. In the practical water cold accumulation engineering application, a plurality of open cold accumulation water tanks are adopted for parallel operation, the overflow condition of part of cold accumulation water tanks exists, and if the overflow condition frequently occurs, water resources are wasted, and the cold energy loss of an air conditioning system is caused. In the prior art, the water cold accumulation air conditioning system can keep the liquid level balance by adding a communicating pipe to the cold accumulation tank to avoid overflow, but the communicating pipe also easily damages an inclined temperature layer. In many practical engineering projects, no communicating pipe is installed, but because of hydraulic imbalance among different water storage tanks, water is often overflowed in the practical operation process, and meanwhile, the problem of inconsistent cold accumulation or cold release speed also occurs. Disclosure of Invention The invention aims to solve the technical problem of providing a water storage tank liquid level balance regulating and controlling system and a regulating and controlling method for a chilled water storage air conditioning system. The water storage tank liquid level balance regulation system of the water cold storage air conditioning system is applied to heat exchange of a user terminal and comprises a refrigerating unit, a first cold storage tank, a second cold storage tank, a chilled water return pipe, a chilled water supply pipe, a chilled water pump, a cold storage pump, a cold discharge pump, a controller and a valve component, wherein the chilled water return pipe, the chilled water pump, the refrigerating unit, the chilled water supply pipe and the user terminal are sequentially communicated and form a circulating water loop, the chilled water return pipe, the first cold storage tank, the cold discharge pump, the chilled water supply pipe and the user terminal are sequentially communicated and form a first cold discharge loop, the chilled water return pipe, the second cold storage tank, the cold storage pump and the refrigerating unit are sequentially communicated and form a second cold storage loop, and the refrigerating unit, the water pump, the cold storage pump, the cold discharge pump and the valve component are sequentially communicated and respectively electrically connected with the controller; The refrigerating unit is provided with the cold accumulation pump on a common pipeline between the refrigerating unit and the first cold accumulation tank and the second cold accumulation tank respectively, the chilled water supply pipe is provided with the cold discharge pump on a common pipeline between the chilled water supply pipe and the first cold accumulation tank and the second cold accumulation tank respectively, the chilled water pump is arranged on a pipeline between the chilled water return pipe and the refrigerating unit, the chilled water return pipe is provided with the valve components on a pipeline between the chilled water return pipe and the first cold accumulation tank and the second cold accumulation tank respectively, a pipeline between the chilled water supply pipe and the first cold accumulation tank and the second cold accumulation tank respectively, a pipeline between the chilled water return pipe and the refrigerating unit and a pipeline between the chilled water supply pipe and the refrigerating unit respectively; the first cold accumulation tank and the second cold accumulation