Cooling water system capable of continuously operating

Abstract

The utility model discloses a continuously operating cooling water system which comprises a heat exchange water path and a control mechanism, the heat exchange water path comprises a first pump and a second pump, the drainage end of the first pump is connected with a first valve through a pipeline, and the drainage end of the second pump is connected with a second valve through a pipeline. The water outlet ends of the first valve and the second valve are connected with the first heat exchange assembly and the second heat exchange assembly through water inlet pipelines. The control mechanism comprises a first temperature sensor installed on the first heat exchange assembly and a second temperature sensor installed on the second heat exchange assembly. Even if the total flow in the pipeline is greatly changed, the total impedance of the pipeline can basically remain unchanged, the phenomenon that the total impedance of the pipeline is greatly increased due to the fact that the opening degree of the valve is small is reduced, and therefore the average energy consumption which needs to be provided by the pump and overcomes the pipeline resistance is reduced. Meanwhile, the range of a high-efficiency area of the pump can be widened, the pump can continuously operate in the high-efficiency area, the input energy consumption of the pump is further reduced, vibration and cavitation are reduced, and the service life of the pump can be prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of cooling water systems, and particularly relates to a continuously operating cooling water system. Background Art

[0002] The cooling water system is an important part of the production workshop. It can provide cooling water for the heat exchangers in the workshop, cool high-temperature equipment or working media, and ensure the safe operation of the workshop.

[0003] The cold water in the cooling water system is pressurized by a pump and transported from the water tank to the heat exchangers in the workshop. After heat exchange with the hot end of the heat exchanger, it flows outside the workshop, releases heat to the air through a cooling tower, and then returns to the water tank, thus realizing the circulation of cooling water. For a cooling water system that operates continuously for a long time and provides cooling water for multiple heat exchangers at the same time, due to the different positions of each heat exchanger in the system, the minimum cooling water flow required also changes with the temperature and production conditions. Therefore, valves are often installed in front of each heat exchanger, and the flow rate of cooling water passing through each heat exchanger is controlled by changing the valve opening for throttling adjustment.

[0004] When throttling adjustment is carried out through a valve, the pipeline characteristic curve will change. At a small opening, the total impedance of the pipeline will increase rapidly, and the energy consumption for transporting a unit mass of cooling water will rise compared with that at a large opening, which is not conducive to energy conservation. For a cooling water system that operates continuously for a long time with a pump for pressurized water supply and provides cooling water for multiple heat exchangers at the same time, when the temperature and production conditions fluctuate greatly, the flow rate of cooling water changes significantly. Throttling adjustment will cause the pump to deviate seriously from the efficient operating area, resulting in strong vibration and cavitation, reducing the working efficiency of the pump and shortening the life of the pump. Content of the Utility Model

[0005] The purpose of the utility model is to provide a continuously operating cooling water system to solve the problems existing in the prior art.

[0006] To achieve the above purpose, the utility model provides the following technical solution: a continuously operating cooling water system, including a heat exchange water circuit and a control mechanism. The heat exchange water circuit includes Pump 1 and Pump 2. The drainage end of Pump 1 is connected to Valve 1 through a pipeline, and the drainage end of Pump 2 is connected to Valve 2 through a pipeline. The water outlet ends of Valve 1 and Valve 2 are connected to Heat Exchange Component 1 and Heat Exchange Component 2 through a water inlet pipeline, and Heat Exchange Component 1 and Heat Exchange Component 2 are connected to an external pipeline through a water outlet pipeline.

[0007] The control mechanism includes Temperature Sensor 1 installed on Heat Exchange Component 1 and Temperature Sensor 2 installed on Heat Exchange Component 2. The control mechanism is also used for starting and stopping, frequency conversion adjustment of Pump 1 and Pump 2, and for adjusting the opening of each valve on Heat Exchange Component 1 and Heat Exchange Component 2.

[0008] Preferably, the first heat exchange assembly includes valve three and valve four connected to one end of the water inlet pipeline. The water outlet end of valve three is connected to the water inlet end of heat exchanger one through a pipeline, and the water outlet end of valve four is connected to the water inlet end of heat exchanger two through a pipeline. The water outlet ends of heat exchanger one and heat exchanger two are connected to one end of the water outlet pipeline.

[0009] Preferably, the second heat exchange assembly includes valve five and valve six connected to one end of the water inlet pipeline. The water outlet end of valve five is connected to the water inlet end of heat exchanger three through a pipeline, and the water outlet end of valve six is connected to the water inlet end of heat exchanger four through a pipeline. The water outlet ends of heat exchanger three and heat exchanger four are connected to one end of the water outlet pipeline.

[0010] Preferably, the control mechanism includes a central controller. The first temperature sensor and the second temperature sensor are installed on the water outlet ends of the high-temperature sides of heat exchanger one, heat exchanger two, heat exchanger three, and heat exchanger four. The transmission lines of the first temperature sensor and the second temperature sensor are both connected to the temperature signal access end of the central controller through a temperature transmitter.

[0011] One signal output end of the central controller is connected to the signal input end of an external frequency converter through a signal line, and the power control output end of the external frequency converter is connected to the power supply controlled ends of pump one and pump two through a cable. Another signal output end of the central controller is connected to the signal input end of an external PLC controller through a signal line, and the electrical signal output end of the external PLC controller is connected to the control modulus signal access ends of valve three, valve four, valve five, and valve six through a cable.

[0012] Compared with the prior art, the beneficial effects of the present utility model are as follows: Through the cooperation of the control mechanism and the heat exchange water circuit, only a reasonable control scheme needs to be designed. By judging the temperature of the high-temperature side of each heat exchanger and the overall average temperature, the start-stop, frequency conversion adjustment of the pump and the opening adjustment of the valve can be realized, so that the cooling water system can not only achieve the individual control of a certain heat exchanger through throttle adjustment, but also achieve the adjustment of the overall flow rate of the cooling water system through the start-stop and frequency conversion adjustment of the pump, enabling the pump to continuously operate in the efficient area.

[0013] After adopting the frequency conversion adjustment and start-stop control method, the use of valve flow adjustment can be minimized. Even if the total flow rate in the pipeline changes significantly, the total impedance of the pipeline can basically remain unchanged, reducing the phenomenon that the total impedance of the pipeline increases significantly due to a small valve opening. Therefore, the average energy consumption required for the pump to overcome the pipeline resistance decreases. At the same time, the efficient area range of the pump can be broadened, continuously operating in the efficient area, further reducing the input energy consumption of the pump, reducing vibration and cavitation, and extending the life of the pump. Description of the Drawings

[0014] Figure 1 Schematic diagram of the overall structure of the present utility model;

[0015] In the figure: 1 Pump 1, 2 Pump 2, 3 Valve 1, 4 Valve 2, 5 Inlet water pipeline, 6 Valve 3, 7 Valve 4, 8 Valve 5, 9 Valve 6, 10 Heat exchanger 1, 11 Heat exchanger 2, 12 Heat exchanger 3, 13 Heat exchanger 4, 14 Outlet water pipeline, 15 Temperature sensor 1, 16 Temperature sensor 2, 17 Central controller. Specific implementation mode

[0016] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model.

[0017] Refer to Figure 1 As shown, the embodiment of the present utility model provides a continuously operating cooling water system, including a heat exchange water path and a control mechanism. The heat exchange water path includes Pump 1 1 and Pump 2 2. Both Pump 1 1 and Pump 2 2 are variable frequency pumps. The drainage end of Pump 1 1 is connected to Valve 1 3 through a pipeline, and the drainage end of Pump 2 2 is connected to Valve 2 4 through a pipeline. Both Valve 1 3 and Valve 2 4 are ball valves. The water outlet ends of Valve 1 3 and Valve 2 4 are connected to Heat exchange component 1 and Heat exchange component 2 through the inlet water pipeline 5. The connection of the inlet water pipeline 5 realizes the water path connection of the water outlet ends of Valve 1 3 and Valve 2 4; Heat exchange component 1 and Heat exchange component 2 are connected to the peripheral pipeline through the outlet water pipeline 14;

[0018] The control mechanism includes Temperature sensor 1 15 installed on Heat exchange component 1 and Temperature sensor 2 16 installed on Heat exchange component 2. The control mechanism is also used for starting and stopping, variable frequency adjustment of Pump 1 1 and Pump 2 2, and for adjusting the opening degrees of each valve on Heat exchange component 1 and Heat exchange component 2.

[0019] The control mechanism realizes the starting and stopping, variable frequency adjustment of each pump and the opening degree adjustment of each valve by judging the temperature on the high temperature side of each heat exchanger and the overall average temperature, so that the cooling water can be individually controlled for a certain heat exchanger through throttling adjustment, and the overall flow rate of the cooling water system can be adjusted by starting and stopping and variable frequency adjustment of the pumps, so that the pumps continuously operate in the high efficiency area.

[0020] Refer to Figure 1 , Heat exchange component 1 includes Valve 3 6 and Valve 4 7 connected to one end of the inlet water pipeline 5. The water outlet end of Valve 3 6 is connected to the water inlet end of Heat exchanger 1 10 through a pipeline, and the water outlet end of Valve 4 7 is connected to the water inlet end of Heat exchanger 2 11 through a pipeline. The water outlet ends of Heat exchanger 1 10 and Heat exchanger 2 11 are connected to one end of the outlet water pipeline 14.

[0021] The second heat exchange component includes valve five 8 and valve six 9 which are connected to one end of the water inlet pipeline 5. The water outlet end of valve five 8 is connected to the water inlet end of heat exchanger three 12 through a pipeline, and the water outlet end of valve six 9 is connected to the water inlet end of heat exchanger four 13 through a pipeline. The water outlet ends of heat exchanger three 12 and heat exchanger four 13 are connected to one end of the water outlet pipeline 14.

[0022] Valve three 6, valve four 7, valve five 8 and valve six 9 are all electronically controlled regulating valves. The heat receiving ends of heat exchanger one 10, heat exchanger two 11, heat exchanger three 12 and heat exchanger four 13 are installed on factory equipment.

[0023] Refer to Figure 1 , the control mechanism includes a central controller 17. The central controller 17 is an industrial control computer. Temperature sensor one 15 and temperature sensor two 16 are installed on the water outlet ends of the high-temperature sides of heat exchanger one 10, heat exchanger two 11, heat exchanger three 12 and heat exchanger four 13. Temperature sensor one 15 and temperature sensor two 16 are needle-type temperature sensors. The transmission lines of temperature sensor one 15 and temperature sensor two 16 are both connected to the temperature signal access end of the central controller 17 through a temperature transmitter;

[0024] One signal output end of the central controller 17 is connected to the signal input end of an external frequency converter through a signal line, and the power control output end of the external frequency converter is connected to the power controlled ends of pump one 1 and pump two 2 through a cable. Another signal output end of the central controller 17 is connected to the signal input end of an external PLC controller through a signal line, and the electrical signal output end of the external PLC controller is connected to the control modulus signal access ends of valve three 6, valve four 7, valve five 8 and valve six 9 through a cable.

[0025] Cooling water flows out from pump one 1 and pump two 2, flows through the water inlet pipeline 5 to heat exchanger one 10, heat exchanger two 11, heat exchanger three 12 and heat exchanger four 13, and then flows out through the water outlet pipeline 14 to be cooled in a cooling tower. Among them, valve one 3 and valve two 4 are fully opened when pump one 1 and pump two 2 are working and fully closed when they are not working.

[0026] Valve Three 6, Valve Four 7, Valve Five 8, and Valve Six 9 can respectively control the flow rates through Heat Exchanger One 10, Heat Exchanger Two 11, Heat Exchanger Three 12, and Heat Exchanger Four 13. Temperature Sensor One 15 and Temperature Sensor Two 16 can monitor the outlet temperatures of the high-temperature sides in Heat Exchanger One 10, Heat Exchanger Two 11, Heat Exchanger Three 12, and Heat Exchanger Four 13, and transmit them to the Central Controller 17 for processing to obtain the average value of the outlet temperatures of the high-temperature sides in Heat Exchanger One 10, Heat Exchanger Two 11, Heat Exchanger Three 12, and Heat Exchanger Four 13. At the same time, the respective temperatures can be displayed on the Central Controller 17, set a safety line, and output an alarm signal when exceeding the safety line. According to the detection results of the outlet temperatures of the high-temperature sides in Heat Exchanger One 10, Heat Exchanger Two 11, Heat Exchanger Three 12, and Heat Exchanger Four 13, the Central Controller 17 will adopt different control methods to control the opening degrees of Valve Three 6, Valve Four 7, Valve Five 8, Valve Six 9, or the start / stop and rotational speeds of Pump One 1 and Pump Two 2.

[0027] In this embodiment, based on Pump One 1 operating at the rated rotational speed, Pump Two 2 being shut down, and the opening degrees of Valve Three 6, Valve Four 7, Valve Five 8, and Valve Six 9 being 0.6, the control strategy adopted by the Central Controller 17 is as follows: When the average temperature > 50°C, Pump One 1 and Pump Two 2 are started simultaneously; when 50°C > average temperature > 40°C, the started pump operates with variable frequency; when the average temperature < 40°C, Pump Two 2 is shut down, and Pump One 1 operates with variable frequency; when the outlet temperature of the high-temperature side of a certain heat exchanger is 5°C higher than the average temperature, increase the valve opening degree by 0.2; when the outlet temperature of the high-temperature side of a certain heat exchanger is 8°C higher than the average temperature, increase the valve opening degree by 0.4; when the outlet temperature of the high-temperature side of a certain heat exchanger is 5°C lower than the average temperature, decrease the valve opening degree by 0.2; when the duration that the outlet temperature of the high-temperature side of a certain heat exchanger is 5°C higher than the average temperature is greater than 12h, issue an alarm signal, close the corresponding valve, and wait for manual processing; when the duration that the average temperature > 50°C is greater than 12h, issue an alarm signal, stop the machine and shut down the production line, and wait for manual processing.

[0028] The working principle of this embodiment is as follows: After adding variable-frequency regulation, the overall flow rate can be adjusted, so that when the flow rate through a certain heat exchanger changes significantly, the sum of the flow rates through other heat exchangers can be maintained basically unchanged;

[0029] After adopting the variable-frequency regulation and start / stop control method, the use of valves to adjust the flow rate can be minimized. Even if the total flow rate in the pipeline changes significantly, the total impedance of the pipeline can basically remain unchanged, reducing the phenomenon that the total impedance of the pipeline increases significantly due to a small valve opening degree. Therefore, the average energy consumption required for the pump to overcome the pipeline resistance decreases. At the same time, the efficient area range of the pump can be broadened, continuously operating in the efficient area, further reducing the input energy consumption of the pump, reducing vibration and cavitation, and extending the life of the pump.

[0030] The above are only the preferred embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model.

Claims

1. A continuously operating cooling water system, characterized in that: The heat exchange circuit comprises a heat exchange component 1 and a control mechanism, wherein the heat exchange component 1 comprises a pump 1 and a pump 2, wherein the discharge end of the pump 1 is connected to a valve 1 through a pipeline, and the discharge end of the pump 2 is connected to a valve 2 through a pipeline, and the water outlet ends of the valve 1 and the valve 2 are connected to a heat exchange component 1 and a heat exchange component 2 through a water inlet pipeline (5), and the heat exchange component 1 and the heat exchange component 2 are connected to an external pipeline through a water outlet pipeline (14); The control mechanism includes a temperature sensor 1 (15) installed on the heat exchange component 1 and a temperature sensor 2 (16) installed on the heat exchange component 2. The control mechanism is also used for starting and stopping the pump 1 (1) and the pump 2 (2), frequency conversion regulation, and for regulating the opening of each valve on the heat exchange component 1 and the heat exchange component 2.

2. A continuously operating cooling water system according to claim 1, characterized in that: The heat exchange component 1 includes a valve 3 (6) and a valve 4 (7) connected to one end of the water inlet pipe (5); the water outlet end of the valve 3 (6) is connected to the water inlet end of the heat exchanger 1 (10) through a pipe, and the water outlet end of the valve 4 (7) is connected to the water inlet end of the heat exchanger 2 (11) through a pipe. The water outlet ends of the heat exchanger 1 (10) and the heat exchanger 2 (11) are connected to one end of the water outlet pipe (14).

3. A continuously operating cooling water system according to claim 2, characterized in that: The heat exchange component 2 includes a valve 5 (8) and a valve 6 (9) connected to one end of the water inlet pipe (5), the water outlet end of the valve 5 (8) is connected to the water inlet end of the heat exchanger 3 (12) through a pipe, the water outlet end of the valve 6 (9) is connected to the water inlet end of the heat exchanger 4 (13) through a pipe, and the water outlet ends of the heat exchanger 3 (12) and the heat exchanger 4 (13) are connected to one end of the water outlet pipe (14).

4. A continuously operating cooling water system according to claim 3, characterized in that: The control mechanism includes a central controller (17), the temperature sensor 1 (15) and the temperature sensor 2 (16) are installed on the water outlet ends of the high-temperature sides of the heat exchanger 1 (10), the heat exchanger 2 (11), the heat exchanger 3 (12) and the heat exchanger 4 (13), and the transmission lines of the temperature sensor 1 (15) and the temperature sensor 2 (16) are connected to the temperature signal access end of the central controller (17) through the temperature transmitter; A signal output end of the central controller (17) is connected to a signal input end of an external frequency converter via a signal line, and a power control output end of the external frequency converter is connected to power controlled ends of pump one (1) and pump two (2) via a cable. Another signal output end of the central controller (17) is connected to a signal input end of an external PLC controller via a signal line, and an electrical signal output end of the external PLC controller is connected to control module signal access ends of valve three (6), valve four (7), valve five (8) and valve six (9) via a cable.

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