Cooling water automatic control system

Abstract

An automatic cooling water control system comprises a circulating water pool, the circulating water pool is connected with a water chilling unit through a pipeline, the water chilling unit is connected with a water cooling tower above the circulating water pool through a pipeline, and a circulating water pump is arranged on a connecting pipeline between the circulating water pool and the water chilling unit; the water chilling unit is connected with the low-level cooler through a pipeline to form a circulation loop, and a cold water pump and a low-level pressure regulating water valve are arranged on the pipeline between the water chilling unit and the low-level cooler; a branch pipeline is further arranged on a connecting pipeline of the water chilling unit and the low-position cooler, the branch pipeline is connected to the high-position cooler, and a high-position pressure regulating water valve is arranged on the branch pipeline. By the adoption of the structure, the working state of each component of the cooling water system can be automatically adjusted when the environment temperature and the production load change, and therefore the purposes of energy conservation and emission reduction are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to energy -conserving control technical field, concretely is a cooling water automatic control system. BACKGROUND

[0002] In the production process of chemical and pharmaceutical industry, the use of cooling device is extremely common, these devices rely on a large number of circulating water and refrigerated water to maintain suitable working temperature. In order to optimize cost and resource utilization, usually adopt the method of single water source supply to multiple water-consuming equipment. However, with the change of external environment temperature and the fluctuation of production load, the demand for cooling system also changes, which requires adjusting multiple parameters such as circulating water pump flow, cooling tower load, cooling water flow and cold water unit load to adapt to different operating conditions. Because the adjustment points involved are numerous and the operation logic is complex, it is extremely difficult to accurately control manually.

[0003] In view of the significant temperature difference of different seasons, production equipment usually designs corresponding seasonal production mode to cope with, only needs to switch mode once when changing season to meet the production demand. But in some areas, the temperature difference between day and night is also significant, even if it does not reach the extreme 30℃ temperature difference between winter and summer, the day and night temperature difference of about 15℃ can also have a significant impact on the efficiency of the cooling water system.

[0004] When the ambient temperature drops, by reducing the circulating water pump flow, refrigerated water pump flow and cooling tower fan speed, etc. can effectively reduce power consumption. However, simply adjusting the working frequency of the pump may cause uneven water distribution in the system due to the difference in resistance of different coolers, that is, the water volume of the cooler on the low-resistance path changes little, while the water volume of the cooler on the high-resistance path may decrease sharply. In view of the numerous factors that need to be adjusted in the cooling water system and the close correlation between them, it is difficult to achieve efficient and accurate control by manual operation. At present, many factories simply adjust the cooling tower air volume when facing the change of ambient temperature, without fully considering the dynamic balance of the whole cooling water system, resulting in unnecessary energy waste, such as invalid circulation of cooling water in the system. Therefore, it is particularly necessary to develop an intelligent control system that can automatically adapt to the change of environment and load. SUMMARY

[0005] The technical problem to be solved by the utility model is to provide a cooling water automatic control system, which can automatically adjust the working state of each component of the cooling water system when the ambient temperature and production load change, so as to realize the purpose of energy saving and emission reduction.

[0006] To solve the above technical problems, the utility model adopts the technical scheme of a kind of cooling water automatic control system, including circulating water pool, the circulating water pool is connected with water chilling unit by pipeline, water chilling unit is connected with cooling tower above circulating water pool by pipeline, and circulating water pump is equipped on the connecting pipeline between circulating water pool and water chilling unit;

[0007] Water chilling unit is connected with low-level cooler to form circulation loop by pipeline, and cold water pump and low-level pressure regulating water valve are equipped on the pipeline between water chilling unit and low-level cooler;

[0008] The connecting pipeline of water chilling unit and low-level cooler is also equipped with branch pipeline, and high-level pressure regulating water valve is equipped on the branch pipeline connected to high-level cooler branch pipeline.

[0009] In the preferred scheme, the low-level cooler is one or more coolers for supplying cooling water to the same floor, the same height section or the same lift section.

[0010] The high-level cooler is one or more coolers for supplying cooling water to the same floor, the same height section or the same lift section.

[0011] The pipeline and equipment resistance between low-level cooler and high-level cooler are inconsistent, and after the pump lift is reduced, the cooling water preferentially ensures the flow of low-level cooler.

[0012] In the preferred scheme, the cooling tower top is equipped with a fan.

[0013] The circulating water pump, fan, water chilling unit and cold water pump are one set or multiple sets, and at least one of each device is configured with a frequency regulator.

[0014] In the preferred scheme, a thermometer is arranged on the outlet pipe of the circulating water pool, the water inlet pipe of the cooling tower and the cold water outlet pipe of the water chilling unit.

[0015] The low-level cooler and high-level cooler back cooling water pipeline are equipped with pressure transmitter and thermometer.

[0016] In the preferred scheme, the circulating water pump, fan, cold water pump, low-level pressure regulating water valve and high-level pressure regulating water valve are connected to the control module.

[0017] The thermometers on the outlet pipe of the circulating water pool, the water inlet pipe of the cooling tower and the cold water outlet pipe of the water chilling unit, and the pressure transmitter and thermometer on the low-level cooler and high-level cooler back cooling water pipeline are also connected to the control module.

[0018] In the preferred scheme, the control module is a DCS control module or a PLC control module.

[0019] In the preferred scheme, the control module dynamically adjusts the rotating speed of the circulating water pump and the cold water pump and the valve position of the low-position pressure regulating water valve and the high-position pressure regulating water valve according to the detection values of the thermometer and the pressure transmitter by a PID algorithm.

[0020] The cooling water automatic control system has the following beneficial effects by adopting the above structure:

[0021] (1) By dynamically adjusting the rotating speed of the circulating water pump and the cold water pump and the position of the pressure regulating water valve, the running state of the cooling water system can be adjusted in real time according to the change of the ambient temperature and the demand of the production load, the power consumption is effectively reduced, and the goal of energy saving and emission reduction is realized.

[0022] (2) The automation intelligent control is realized by the control module, the best working state of each component under different working conditions is ensured, the energy waste phenomenon (such as invalid circulation of cooling water) is avoided, and the energy efficiency ratio of the whole cooling system is improved.

[0023] (3) Whether the diurnal temperature difference is large or the seasonal temperature change is large, the system can automatically adapt and make corresponding adjustment. In addition, different cooler configurations can also be flexibly coped with, and the universality and adaptability of the system are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0024] The utility model will be further described in connection with the drawings and embodiments:

[0025] Figure 1 It is the whole structure schematic diagram of the utility model.

[0026] In the drawing: circulating water pool 1, circulating water pump 2, cooling tower 3, fan 4, cold water unit 5, cold water pump 6, low-position pressure regulating water valve 7, low-position cooler 8, high-position pressure regulating water valve 9, high-position cooler 10, control module 11, thermometer 12, pressure transmitter 13. DETAILED DESCRIPTION

[0027] Embodiment 1:

[0028] As Figure 1 In the embodiment, a cooling water automatic control system comprises a circulating water pool 1, the circulating water pool 1 is connected with a cold water unit 5 through a pipeline, the cold water unit 5 is connected with a cooling tower 3 above the circulating water pool 1 through a pipeline, and a circulating water pump 2 is arranged on the connecting pipeline between the circulating water pool 1 and the cold water unit 5.

[0029] The cold water unit 5 is connected with a low-position cooler 8 through a pipeline to form a circulating loop, and a cold water pump 6 and a low-position pressure regulating water valve 7 are arranged on the pipeline between the cold water unit 5 and the low-position cooler 8.

[0030] The connecting pipe of the water chiller 5 and the low-level cooler 8 is also provided with a branch pipe, and the branch pipe is connected to the high-level cooler 10 and provided with a high-level pressure regulating valve 9.

[0031] In the preferred embodiment, the low-level cooler 8 is one or more coolers of the same floor, the same height section or requiring the same lift section for cooling water.

[0032] The high-level cooler 9 is one or more coolers of the same floor, the same height section or requiring the same lift section for cooling water.

[0033] The pipe and equipment resistance between the low-level cooler 8 and the high-level cooler 9 are inconsistent, and after the pump lift is reduced, the cooling water is preferentially ensured to flow to the low-level cooler 8.

[0034] In the preferred embodiment, the cooling tower 3 is provided with a fan 4 at the top.

[0035] The circulating water pump 2, the fan 4, the water chiller 5 and the cooling water pump 6 are one or more sets, and at least one of each device is provided with a frequency regulator.

[0036] In the preferred embodiment, the outlet pipe of the circulating water pool 1, the water inlet pipe of the cooling tower 3 and the cooling water outlet pipe of the water chiller 5 are all provided with a thermometer 12.

[0037] The cooling water return pipes of the low-level cooler 8 and the high-level cooler 10 are provided with a pressure transmitter 13 and a thermometer 12.

[0038] In the preferred embodiment, the circulating water pump 2, the fan 4, the cooling water pump 6, the low-level pressure regulating valve 7 and the high-level pressure regulating valve 9 are all connected to the control module 11.

[0039] The thermometers on the outlet pipe of the circulating water pool 1, the water inlet pipe of the cooling tower 3 and the cooling water outlet pipe of the water chiller 5, and the pressure transmitter and the thermometer on the cooling water return pipes of the low-level cooler 8 and the high-level cooler 10 are also connected to the control module 11.

[0040] In the preferred embodiment, the control module 11 is a DCS control module or a PLC control module.

[0041] In the preferred embodiment, the control module 11 dynamically adjusts the rotating speed of the circulating water pump 2 and the cooling water pump 6 and the valve position of the low-level pressure regulating valve 7 and the high-level pressure regulating valve 9 according to the detection values of the thermometer 12 and the pressure transmitter 13 through the PID algorithm.

[0042] Example 2:

[0043] Automatic adjustment under ambient temperature change:

[0044] Assuming the ambient temperature of the production system gradually decreases from a maximum of 30°C at noon to 15°C at midnight:

[0045] Step 1: As the ambient temperature decreases, the heat dissipated by the system into the atmosphere increases, resulting in a decrease in cooling water load.

[0046] Step 2: The chiller 5 detects the decrease in cooling water inlet temperature and automatically adjusts the load to maintain the chilled water temperature at 7°C.

[0047] Step 3: As the cooling water load decreases, the return water temperature of the circulating water tank 1 also decreases, and the control system will accordingly reduce the operating frequency of the fan 4 and adjust the circulating water pump 2 speed to ensure that the temperature difference between the incoming and outgoing circulating water remains at 5°C.

[0048] Step 4: When the cooling water load further decreases, the flow of the cooling water pump 6 is adjusted according to the change in the outlet water temperature of the low-level cooler 8. Since the high-level cooler 10 requires a higher head, its cooling water flow is preferentially reduced compared to the low-level cooler 8. At this time, the low-level pressure regulating water valve 7 will automatically adjust to maintain the outlet water temperature of the high-level cooler 10 at 12°C.

[0049] Step 5: Through the above series of adjustment measures, the power consumption of the entire system is significantly reduced, achieving the goal of energy saving and consumption reduction.

[0050] Example 3:

[0051] Response to temperature rise from night to day:

[0052] Assuming the ambient temperature of the production system gradually increases from a minimum of 10°C at night to 25°C during the day:

[0053] Step 1: As the ambient temperature increases, the heat dissipated by the system into the atmosphere decreases, resulting in an increase in cooling water load.

[0054] Step 2: The chiller 5 automatically adjusts the load according to the increase in cooling water inlet temperature, maintaining the chilled water temperature at 7°C; at the same time, as the cooling water load increases, the return water temperature of the circulating water tank 1 increases, and the operating frequency of the fan 4 and circulating water pump 2 is accordingly increased.

[0055] Step 3: The flow of the cooling water pump 6 increases with the increase in the outlet water temperature of the low-level cooler 8. Since the high-level cooler 10 requires a higher head, its cooling water flow increases more slowly compared to the low-level cooler 8. At this time, the low-level pressure regulating water valve 7 will automatically adjust the opening to maintain the outlet water temperature of the high-level cooler 10 at 12°C.

[0056] Step 4: By dynamically adjusting the working state of each component, the temperature difference of the chilled water entering and leaving the chiller 5 is maintained at about 5°C, and the entire system can operate stably under automatic control, adapting to the impact of temperature changes.

[0057] Example 4:

[0058] Handling a single cooler shutdown:

[0059] Assuming that the high-level cooler 10 is shut down due to equipment reduction, the load gradually decreases to zero:

[0060] Step 1: As the load of the high-level cooler 10 decreases, the outlet water temperature decreases, and the system automatically increases the opening of the low-level pressure regulating valve 7 until it is fully open. If the outlet water temperature of the high-level cooler 10 is still high, the opening of the high-level pressure regulating valve 9 is automatically reduced until it is closed.

[0061] Step 2: The chiller 5 adjusts the load according to the new cooling demand, and at the same time, reduces the working frequency of the circulating water pump 2 to ensure efficient operation of the system under the new working condition.

[0062] Step 3: The output of the chilled water pump 6 is directed to the low-level cooler 8, and after the outlet water temperature of the low-level cooler 8 decreases, the frequency of the chilled water pump 6 is also reduced accordingly, thereby achieving the reduction of power consumption of the entire system and achieving the effect of energy saving and emission reduction.

Claims

1. An automatic cooling water control system comprising a circulating water tank (1), characterized in that: The circulating water pool (1) is connected with the water chiller (5) through a pipeline, the water chiller (5) is connected with the cooling tower (3) above the circulating water pool (1) through a pipeline, and a circulating water pump (2) is arranged on the pipeline between the circulating water pool (1) and the water chiller (5); The water chiller (5) is connected with the low-position cooler (8) through a pipeline to form a circulating loop, and a cold water pump (6) and a low-position pressure regulating water valve (7) are arranged on the pipeline between the water chiller (5) and the low-position cooler (8); The pipeline connecting the water chiller (5) and the low-position cooler (8) is further provided with a branch pipeline, and the branch pipeline is connected to the high-position cooler (10); the branch pipeline of the high-position cooler (10) is provided with a high-position pressure regulating water valve (9).

2. The automatic cooling water control system according to claim 1, characterized in that: The low-position cooler (8) is one or more coolers for supplying cooling water at the same floor, the same height section or the same lift section. The high-position cooler (9) is one or more coolers for supplying cooling water at the same floor, the same height section or the same lift section. The pipeline and equipment resistance between the low-position cooler (8) and the high-position cooler (9) are inconsistent, and after the pump lift is reduced, the cooling water preferentially ensures the flow of the low-position cooler (8).

3. The automatic cooling water control system of claim 1, wherein: The cooling tower (3) is provided with a fan (4) at the top; The circulating water pump (2), the fan (4), the water chiller (5) and the cold water pump (6) are one set or multiple sets, and at least one of each device is provided with a frequency regulator.

4. The automatic cooling water control system of claim 3, wherein: Temperature gauges (12) are arranged on the outlet pipe of the circulating water pool (1), the water inlet pipe of the cooling tower (3) and the cold water outlet pipe of the water chiller (5); The cooling water return pipelines of the low-position cooler (8) and the high-position cooler (10) are provided with pressure transmitters (13) and temperature gauges (12).

5. The automatic cooling water control system of claim 4, wherein: The circulating water pump (2), the fan (4), the cold water pump (6), the low-position pressure regulating water valve (7) and the high-position pressure regulating water valve (9) are connected to the control module (11); The temperature gauges on the outlet pipe of the circulating water pool (1), the water inlet pipe of the cooling tower (3) and the cold water outlet pipe of the water chiller (5) and the pressure transmitters and temperature gauges on the cooling water return pipelines of the low-position cooler (8) and the high-position cooler (10) are also connected to the control module (11).

6. The automatic cooling water control system of claim 5, wherein: The control module (11) is a DCS control module or a PLC control module.

7. The automatic cooling water control system of claim 5, wherein: The control module (11) dynamically adjusts the rotating speed of the circulating water pump (2) and the cold water pump (6) and the valve position of the low-position pressure regulating water valve (7) and the high-position pressure regulating water valve (9) according to the detection values of the temperature gauges (12) and the pressure transmitters (13) through a PID algorithm.

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