Control system for loading and unloading and output regulation of water chilling unit

Abstract

The utility model provides a control system for loading and unloading and output adjustment of a water chilling unit. The control system comprises a water return pipeline; a water supply line; the water inlet ends of the water chilling units are communicated with the water return pipeline through water return branch pipes, and the water outlet ends of the water chilling units are communicated with the water supply pipeline through water supply branch pipes; the N cold water pumps are arranged on the N water return branch pipes in a one-to-one correspondence manner; and the PLC is in control connection with the N water chilling units and the N cold water pumps at the same time. The control system for load increasing, load reducing and output adjusting of the water chilling unit is a reasonable, scientific and reasonable control system device and aims at monitoring, controlling and adjusting the starting number, the working load percentage, the working frequency and the like of the water chilling unit in real time, and safe, reliable, efficient and energy-saving operation of the water chilling unit is achieved. The comfort requirement is considered, the working intensity of operators is reduced, the safety risk is reduced, and energy-saving and efficient operation can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of heating and ventilation, and in particular to a control system for load addition and reduction and output adjustment of a chiller. Background Art

[0002] After running for a period of time, the HVAC system can achieve a balance between supply and demand. However, with the constant changes in outdoor sunlight, wind speed, wind direction and other meteorological parameters, as well as the number of people and equipment in the room, the required cooling load of the exhibition hall space is also changing in real time. The change in the required cooling load requires that the number of chillers turned on, the percentage of single chiller workload, etc. should also be adjusted in time to adapt to the above changes in cooling load.

[0003] At present, operators usually determine the number of units to be started based on experience. When users of the exhibition hall report that the equipment is too cold or too hot, operators tentatively increase or decrease the number of units in operation one by one, and gradually find a rough balance point based on experience. If the cooling load changes frequently, the operator must accurately, quickly, and in real time make adjustment plans for multiple equipment systems and put them into practice. Operators rarely have such capabilities. In addition, it is difficult to prevent misjudgment when adjusting plans quickly and in real time, which may lead to safety risks in equipment operation.

[0004] Therefore, in view of the shortcomings of the existing technology, it is necessary to design a control system for adding and reducing loads and adjusting output of the chiller to solve the above problems. Utility Model Content

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the utility model aims to provide a control system for adding and reducing load and adjusting output of a chiller.

[0006] In order to achieve the above-mentioned purpose and other related purposes, the technical solution provided by the utility model is: a control system for adding and reducing load and adjusting output of a chiller, comprising:

[0007] Return pipe;

[0008] Water supply pipelines;

[0009] N chillers, the water inlet of each chiller is connected to the return water pipeline via a return water branch pipe, and the water outlet of each chiller is connected to the supply water pipeline via a supply water branch pipe;

[0010] N cold water pumps, the N cold water pumps are arranged one by one on the N return water branch pipes;

[0011] A PLC controller is connected to the N chillers and the N chilled water pumps for control.

[0012] The preferred technical solution is: a water flow signal switch is provided on the return water branch pipe and between the cold water pump and the chiller.

[0013] The preferred technical solution is: a return water pressure sensor is provided on the return water pipeline.

[0014] The preferred technical solution is: a return water temperature sensor is provided on the return water pipeline.

[0015] The preferred technical solution is: a water supply pressure sensor is provided on the water supply pipeline.

[0016] The preferred technical solution is: a water supply temperature sensor is provided on the water supply pipeline.

[0017] The preferred technical solution is that the PLC controller is simultaneously connected to the water flow signal switch, the return water pressure sensor, the return water temperature sensor, the water supply pressure sensor and the water supply temperature sensor signal.

[0018] Due to the application of the above technical solution, the utility model has the following beneficial effects:

[0019] The utility model proposes a control system for adding and reducing load and adjusting output of a chiller, which is a reasonable, scientific and reasonable control system device, which aims to monitor, control and adjust the number of openings, workload percentage, working frequency, etc. of the chiller in real time, so as to achieve safe, reliable, efficient and energy-saving operation of the chiller. It takes into account the comfort requirements, reduces the workload of operators, reduces safety risks, and achieves energy-saving and efficient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The utility model is a schematic diagram of a control system for load addition and reduction and output adjustment of a chiller. DETAILED DESCRIPTION

[0021] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0022] See also Figure 1. It should be noted that in the description of the present utility model, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. Terms such as "horizontal", "vertical", and "overhanging" do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Example:

[0025] like Figure 1 As shown, according to an overall technical concept of the utility model, a control system for adding and reducing load and adjusting output of a chiller is provided, comprising:

[0026] Return pipe 1;

[0027] Water supply pipeline 2;

[0028] N chillers 3, the water inlet of the chiller 3 is connected to the return water pipeline 1 through the return water branch pipe 31, and the water outlet of the chiller 3 is connected to the water supply pipeline 2 through the water supply branch pipe 32;

[0029] N cold water pumps 4, which are arranged one by one on the N return water branch pipes 31;

[0030] The PLC controller 5 is controlled and connected to N chillers 3 and N chilled water pumps 4 at the same time.

[0031] like Figure 1As shown, in an exemplary embodiment of the present utility model, a water flow signal switch 6 is provided on the return water branch pipe 31 and between the cold water pump 4 and the chiller 3 .

[0032] like Figure 1 As shown, in an exemplary embodiment of the present utility model, a return water pressure sensor 71 is provided on the return water pipeline 1 for monitoring the water pressure in the return water pipeline 1 .

[0033] like Figure 1 As shown, in an exemplary embodiment of the present utility model, a return water temperature sensor 81 is provided on the return water pipeline 1 for monitoring the water temperature in the return water pipeline 1 .

[0034] like Figure 1 As shown, in an exemplary embodiment of the present utility model, a water supply pressure sensor 81 is provided on the water supply pipeline 2 for monitoring the water pressure in the water supply pipeline 2 .

[0035] like Figure 1 As shown, in an exemplary embodiment of the present utility model, a water supply temperature sensor 82 is provided on the water supply pipeline 2 for monitoring the water temperature in the water supply pipeline 2 .

[0036] like Figure 1 As shown, in an exemplary embodiment of the present utility model, the PLC controller 5 is simultaneously connected to the water flow signal switch 6, the return water pressure sensor 71, the return water temperature sensor 72, the supply water pressure sensor 81 and the supply water temperature sensor 82.

[0037] The PLC controller controls the load increase or decrease of the chiller 3 according to the relationship between the pressure difference and the temperature difference in the return water pipeline 1 and the water supply pipeline 2 and the set value.

[0038] Specifically, the system performs load addition and reduction calculations every 15 minutes (user-resettable), and takes 6 groups of chillers 3 as an example:

[0039] Condition 1 for adding a machine: Compare the "water outlet temperature of any chiller 3 (obtained through the water supply temperature sensor 82)" with its set value. When it is 1.0 degrees higher than its set value and the unit current percentage (FLA%) is greater than 90%, condition 2 for adding a machine is met.

[0040] Condition 2 for adding a machine: compare the "water temperature of the chiller inlet main pipe (obtained through the return water temperature sensor 72)" with its set value. When it is 2.5 degrees higher than its set value, condition 1 for adding a machine is met.

[0041] When both conditions 1 and 2 for adding a machine are met, the PLC controller 5 issues an "add machine request" instruction.

[0042] Condition 1 for reducing the number of machines:

[0043] When the two groups of chillers 3 are in operation, the average FLA% is less than 40%, and the chilled water outlet temperature of any group is 1.0 degrees lower than its set value;

[0044] When the three chillers 3 are in operation, the average FLA% is <50%, and the chilled water outlet temperature of any group is 1.0 degrees lower than its set value;

[0045] When the four chillers 3 are in operation, the average FLA% is less than 60%, and the chilled water outlet temperature of any group is 1.0 degrees lower than its set value;

[0046] When the five chillers 3 are in operation, the average FLA% is < 65%, and the chilled water outlet temperature of any group is 1.0 degrees lower than its set value;

[0047] When the six chillers 3 are in operation, the average FLA% is less than 75%, and the chilled water outlet temperature of any group is 1.0 degrees lower than its set value;

[0048] Condition 2 for reducing the number of machines: comparing the "water temperature of the chiller inlet main pipe (obtained through the return water temperature sensor 72)" with its set value, if it is 0.5 degrees lower than its set value;

[0049] When the reduction condition 1 or the reduction condition 2 is met, the PLC controller 5 issues a "reduction request" instruction.

[0050] Therefore, the utility model has the following advantages:

[0051] The utility model proposes a control system for adding and reducing load and adjusting output of a chiller, which is a reasonable, scientific and reasonable control system device, which aims to monitor, control and adjust the number of openings, workload percentage, working frequency, etc. of the chiller in real time, so as to achieve safe, reliable, efficient and energy-saving operation of the chiller. It takes into account the comfort requirements, reduces the workload of operators, reduces safety risks, and achieves energy-saving and efficient operation.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A control system for load addition and reduction and output adjustment of a chiller, characterized in that: include: Return pipe; Water supply pipelines; N chillers, the water inlet of each chiller is connected to the return water pipeline via a return water branch pipe, and the water outlet of each chiller is connected to the water supply pipeline via a supply water branch pipe; N cold water pumps, the N cold water pumps are arranged one by one on the N return water branch pipes; A PLC controller is connected to the N chillers and the N chilled water pumps for control.

2. A control system for load addition and reduction and output adjustment of a chiller according to claim 1, characterized in that: A water flow signal switch is provided on the water return branch pipe and between the cold water pump and the cold water unit.

3. A control system for load addition and reduction and output adjustment of a chiller according to claim 2, characterized in that: A return water pressure sensor is arranged on the return water pipeline.

4. A control system for load addition and reduction and output adjustment of a chiller according to claim 3, characterized in that: A return water temperature sensor is arranged on the return water pipeline.

5. A control system for load addition and reduction and output adjustment of a chiller according to claim 4, characterized in that: A water supply pressure sensor is arranged on the water supply pipeline.

6. A control system for load addition and reduction and output adjustment of a chiller according to claim 5, characterized in that: A water supply temperature sensor is arranged on the water supply pipeline.

7. A control system for load addition and reduction and output adjustment of a chiller according to claim 6, characterized in that: The PLC controller is simultaneously connected to the water flow signal switch, the return water pressure sensor, the return water temperature sensor, the supply water pressure sensor and the supply water temperature sensor signal.

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