Start-stop optimization control method for central air-conditioning systemTechnical Field
The invention relates to air conditioner energy-saving control, in particular to a method for optimally controlling starting and stopping of a central air conditioning system.
Background
With the flourishing development of economy and technology, various intelligent buildings and production processes have higher and higher requirements on air conditioners, and the air conditioner supply time is greatly prolonged and even supplied all the year round. But the air conditioner load difference is larger due to different seasons, different weather and different time periods. And the proportion of the energy consumption of the air conditioner in the total energy consumption of the air conditioner is larger and larger, so that the energy-saving control of the air conditioner is more and more emphasized. The invention name of the prior art is as follows: a method and a device for controlling the start and stop of a central air-conditioning system are disclosed in application number CN201110085547.2, but energy conservation is not considered.
Disclosure of Invention
1. The technical problem to be solved is as follows:
aiming at the technical problems, the invention provides a start-stop optimization control method of a central air-conditioning system, which is used for carrying out start-stop optimization aiming at three links with the largest energy consumption ratio in the use process of the central air-conditioning system, and can consider energy conservation while controlling the start-stop of the air-conditioning system.
2. The technical scheme is as follows:
a central air conditioning system start-stop optimization control method is characterized in that: the method comprises the following steps:
the method comprises the following steps: collecting the running parameters of a water chiller unit, a chilled water system and a cooling water system in a central air-conditioning system.
Step two: the start and stop control method of the water chilling unit comprises the following steps: the water chilling unit comprises a plurality of water chilling units; the plurality of water chilling units run in parallel; and the water chilling units are sequentially increased or decreased according to the load.
Step three: the start-stop control method of the chilled water system comprises the following steps: and comparing the actual main pipe pressure difference value with a preset pressure difference value to control the rotating speed of the water pump, and stabilizing the main pipe pressure difference value at the preset value through flow regulation.
Step four: a start-stop control method of a cooling water system; the outlet temperature of the cooling water pump is used as a variable frequency control signal in the cooling water system to control the operation of the cooling water pump, so that the variable flow of the cooling water system is controlled.
Further, the specific process of the second step is as follows: when receiving a starting command, starting a first water chiller with the minimum refrigerating capacity; if the load of the first water chiller reaches a full value, a second water chiller with a second smaller refrigerating capacity is started; and if the first water chiller and the second water chiller are in full-load operation, opening the third water chiller until all the water chillers are in full-load operation.
Further, in the second step, when the total load rate of the water chilling units is detected to be lower than the preset value, one or more of the units are closed according to the size of the refrigerating capacity.
Further, the third step is specifically: the main pipe pressure difference value of the collected chilled water system is compared with a preset pressure difference value, if the main pipe pressure difference value is larger than the preset pressure difference value, the running speed of the water pump is increased, and if the main pipe pressure difference value is smaller than the preset pressure difference value, the running speed of the water pump is reduced.
Further, the fourth specific process of the step is as follows: the temperature of the outlet of the cooling pump of the collected cooling water is compared with a preset outlet temperature range, and the operating frequency of the cooling water pump is selected according to the outlet temperature range.
3. Has the advantages that:
(1) the starting and stopping of the water chilling unit are controlled by the number of the water chilling units, and the method is simple and easy to implement.
(2) The method for controlling the start and the stop of the chilled water system is characterized in that the actual main pipe pressure difference value is compared with the preset pressure difference value, and the control method is simple and easy to realize.
The method is suitable for starting and stopping the central air conditioner with smaller power by respectively carrying out start-stop optimization on the three links with the maximum energy consumption proportion of the central air conditioner.
Detailed Description
A central air conditioning system start-stop optimization control method is characterized in that: the method comprises the following steps:
the method comprises the following steps: collecting the running parameters of a water chiller unit, a chilled water system and a cooling water system in a central air-conditioning system.
Step two: the start and stop control method of the water chilling unit comprises the following steps: the water chilling unit comprises a plurality of water chilling units; the plurality of water chilling units run in parallel; and the water chilling units are sequentially increased or decreased according to the load.
Step three: the start-stop control method of the chilled water system comprises the following steps: and comparing the actual main pipe pressure difference value with a preset pressure difference value to control the rotating speed of the water pump, and stabilizing the main pipe pressure difference value in the preset value through flow regulation.
Step four: a start-stop control method of a cooling water system; the outlet temperature of the cooling water pump is used as a variable frequency control signal in the cooling water system to control the operation of the cooling water pump, so that the variable flow of the cooling water system is controlled.
Further, the specific process of the second step is as follows: when receiving a starting command, starting a first water chiller with the minimum refrigerating capacity; if the load of the first water chiller reaches a full value, a second water chiller with a second smaller refrigerating capacity is started; and if the first water chiller and the second water chiller are in full-load operation, opening the third water chiller until all the water chillers are in full-load operation.
Further, in the second step, when the total load rate of the water chilling units is detected to be lower than the preset value, one or more of the units are closed according to the size of the refrigerating capacity.
Further, the third step is specifically: the main pipe pressure difference value of the collected chilled water system is compared with a preset pressure difference value, if the main pipe pressure difference value is larger than the preset pressure difference value, the running speed of the water pump is increased, and if the main pipe pressure difference value is smaller than the preset pressure difference value, the running speed of the water pump is reduced.
Further, the fourth specific process of the step is as follows: the temperature of the outlet of the cooling pump of the collected cooling water is compared with a preset outlet temperature range, and the operating frequency of the cooling water pump is selected according to the outlet temperature range.
The method focuses on respectively starting and stopping three key energy consumption parts of the central air conditioner. In the operation of the central air conditioner, the water chilling unit, the chilled water system and the cooling water system are respectively controlled to operate, so that the temperature control of the air conditioner is realized, the energy consumption control can be realized, and the calculation is simple and easy to implement.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.