KR102534986B1 - Closed expansion tank and auto pressure control type water cooling system for transformer - Google Patents

Abstract

The present invention relates to a closed expansion tank and an automatic pressure control type transformer water cooling system. A plurality of sealed expansion tanks installed in the underground storage room of the transformer water cooling system operating in such a way that water cooled while passing through the trickle pipe of the cooling tower is returned to the water circulation pump through a redon header. ; a pipe connected to directly supply water from one of the closed expansion tanks of the underground storage tank to a cooling tower; first and second pressure sensor units for respectively detecting the pressure of the closed expansion tank; a control unit that controls a cooling tower, a valve, a pump, and an inverter, which are pipe connection components of the transformer water cooling system, based on the pressure values detected through the first and second pressure sensor units; And in preparation for the case where automatic control of the transformer water cooling system by the control unit is impossible, status information and control signals for remote control through the linkage of SCADA (supervisory control and data acquisition) system and MMI (man machine interface) system It includes; communication unit for transmission of.

Description

Closed expansion tank and automatic pressure control type transformer water cooling system

The present invention relates to a closed expansion tank and an automatic pressure control type transformer water cooling system, and more particularly, to a sealed expansion tank, automatic pressure monitoring and control, and a circulating water seal valve set in an underground storage room unaffected by outside air temperature. It relates to a sealed expansion tank and an automatic pressure control transformer water cooling system that replaces the role of an existing elevated water tank through configuration, thereby eliminating damage from freezing in winter and preventing air mixing.

1 is an exemplary view showing a schematic pipe connection configuration of a conventional transformer water cooling system.

As shown in FIG. 1, the pipe connection configuration of the conventional transformer water cooling system includes a water circulation pump 11, a cooling header 12, an MTR 13, and a warm ) header 14, supply header 15, cooling tower 16, return header 17, underground storage tank 18, makeup water pump 19, makeup water tank 21, and It includes an expansion water tank (22).

Here, the make-up water tank 21 and the expansion water tank 22 are elevated water tanks 20, and while pumping and storing the water to be used in a water tank installed on the roof of a building or a separate high location, when necessary, natural pressure (ie, It is a water tank installed to supply water according to gravity).

In the conventional transformer water cooling system, the water circulation pump 11 is operated to circulate the sealed water circulation pipe (or the transformer cooling circulation water sealed system), and the MTR 13 (or the heat exchanger of the transformer) The heated water is supplied to the cooling tower 16 through the warm header 14 and the supply header 15, and the water cooled while passing through a trickle pipe (not shown) of the cooling tower 16 is supplied to the redundant header ( 17) and returns to the water circulation pump 11.

At this time, the conventional transformer water cooling system operates a water spray pump (not shown) in the cooling tower 16 by the water supplied from the elevated water tank 20 and sprays it to a trickle pipe (not shown) for cooling efficiency. raises

In addition, the water in the underground water storage tank 18 is supplied to the elevated water tank 20 through the make-up water pump 19, and the elevated water tank 20 consists of two storage tanks, a make-up water tank 21 and an expansion water tank. It consists of (22).

At this time, the make-up water tank 21 supplies water evaporated after cooling the trickle pipe (not shown) in the cooling tower 16, and the expansion water tank 22 supplies pressure using a drop to the return header 17. It maintains the sealed water circulation pipe (or the closed system of the cooling water circulation water of the transformer) and serves to buffer the volume change of the circulation water due to the contraction and expansion of the sealed water circulation pipe.

For reference, in the conventional transformer water cooling system, the expansion water tank 22 of the elevated water tank 20 is an open type, and the insufficient water level in the expansion water tank 22 is supplemented from the underground water storage tank 18, It is a method of supplying expansion water by a higher drop than the cooling tower 16.

By the way, in the conventional transformer water cooling system, the elevated water tank 20 is used to supply water cooling pipe expansion water and supplemental water for cooling tower sprinkling (ie, sprinkling water), but there is little flow of water in winter Expansion water supply pipe and elevated water tank valves (i.e., water level control valve and opening/closing valve, etc.) are frozen and broken, and also the cause of cooling water circulation failure and pipe corrosion due to air mixing in the water circulation pipe according to the open expansion tank method There is a problem with providing In addition, in the case of an underground complex substation, there is a problem that damage to the substation building may occur due to water leakage when high-rise cooling tower pipes and valves are frozen.

Therefore, there is a need for a water cooling system that can prevent the above problems, operate more efficiently, and has an excellent maintenance cost reduction effect.

According to one aspect of the present invention, the present invention has been created to solve the above problems, and is a sealed expansion tank, automatic pressure monitoring control, and a circulating water seal valve set in an underground storage room that is not affected by the outside air temperature. The purpose is to provide a sealed expansion tank and an automatic pressure control type transformer water cooling system that can eliminate freezing damage in winter and prevent air mixing by replacing the role of the existing elevated water tank through the configuration.

In the closed expansion tank and automatic pressure control type transformer water cooling system according to one aspect of the present invention, a water circulation pump is operated to circulate the transformer cooling circulating water sealed system, and the water heated in the heat exchanger of the transformer is supplied to the warm header and the supply A plurality of closed types installed in the underground storage tank of the transformer water cooling system that operates in such a way that the water supplied to the cooling tower through the header and cooled while passing through the trickle pipe of the cooling tower returns to the water circulation pump through the redundant header. expansion tank; a pipe connected to directly supply water from one of the closed expansion tanks of the underground storage tank to a cooling tower; first and second pressure sensor units for respectively detecting the pressure of the closed expansion tank; a control unit that controls a cooling tower, a valve, a pump, and an inverter, which are pipe connection components of the transformer water cooling system, based on the pressure values detected through the first and second pressure sensor units; And in preparation for the case where automatic control of the transformer water cooling system by the control unit is impossible, status information and control signals for remote control through the linkage of SCADA (supervisory control and data acquisition) system and MMI (man machine interface) system Characterized in that it comprises a; communication unit for transmission of.

In the present invention, the control unit includes a cooling tower spray pump & fan and cooling water valve control unit for controlling the spray pump & fan and cooling water valve inside the cooling tower; a cooling water temperature and cooling tower spray tank water level controller for controlling the cooling water temperature inside the cooling tower and the water level of the spray tank; a main control unit controlling the replenishment water pump in an inverter manner; a circulating water pressure range setting unit configured to set a pressure value of circulating water circulated through the water circulation pump; and a make-up water pump control unit controlling the make-up water pump to start at a preset lower limit pressure and stop at a preset upper pressure limit value.

In the present invention, the control unit integrally performs the functions of the cooling tower spray pump & fan and cooling water valve control unit, cooling water temperature and cooling tower spray tank water level control unit, main control unit, circulating water pressure range setting unit, and make-up water pump control unit. It is characterized by being implemented to be able to.

In the present invention, the sealed expansion tank is an air layer using a tube at the top of the inside to increase the efficiency of lifting capacity when the make-up water pump is operated and to prevent contraction and expansion of the pipe and water hammer caused by pump operation. It is characterized in that it is formed into a structure that absorbs fluctuations in pressure by its elasticity.

In the present invention, the control unit automatically drives the make-up water pump according to the change in pressure detected through the water pipe pressure sensor in order to automatically maintain a predetermined constant pressure for the sealed expansion tank and increase efficiency. It is characterized in that for performing the speed control of the motor to do.

In the present invention, supplemental water supplied from the closed expansion tank toward the cooling tower so that the pressure supplied to the pipe from the closed expansion tank is supplied at a pressure corresponding to the drop of the existing elevated water tank method. Between the piping and the piping that supplies water to the cooling circulating water piping that circulates the transformer heat exchanger, valves for the configuration of the cooling circulating water sealing system are installed. , and a valve set including a pressure gauge.

In the present invention, the control unit is characterized in that the control unit operates the plurality of replenishment water pumps in a first and second manner, starting at a preset lower limit of the set pressure and stopping at the upper limit of the set pressure.

In the present invention, the control unit operates at least one valve of the make-up water supply pipe to drain the water in the pipe and valve in order to prevent freezing and bursting of the make-up water pipe for supplying cooling tower spray water exposed to the outside air during the winter period. ) is characterized by doing.

According to one aspect of the present invention, the present invention replaces the role of the existing elevated water tank through the configuration of a sealed expansion tank, automatic pressure monitoring control, and a circulating water sealing valve set in an underground storage room that is not affected by the outside air temperature. , so that there is no damage from freezing in winter and air mixing is prevented.

1 is an exemplary view showing a schematic pipe connection configuration of a conventional transformer water cooling system;
2 is an exemplary view showing a schematic configuration of a water cooling system for a closed expansion tank and an automatic pressure control type transformer according to an embodiment of the present invention.
3 is an exemplary view showing a schematic pipe connection configuration of a transformer water cooling system according to an embodiment of the present invention.

Hereinafter, an embodiment of a closed expansion tank and an automatic pressure control type transformer water cooling system according to the present invention will be described with reference to the accompanying drawings.

In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

2 shows a schematic configuration of a closed expansion tank and an automatic pressure control type transformer water cooling system according to an embodiment of the present invention (hereinafter, in this embodiment, for convenience of description, it may be simply referred to as a transformer water cooling system). is an example

And Figure 3 is an exemplary view showing a schematic pipe connection configuration of the transformer water cooling system according to an embodiment of the present invention.

As shown in FIG. 2, the sealed expansion tank and automatic pressure control transformer water cooling system according to the present embodiment includes a first pressure sensor unit 210, a second pressure sensor unit 220, a control unit 230, and a communication unit 240 (eg RTU, Remote Terminal Unit).

The closed expansion tank and automatic pressure control type transformer water cooling system according to the present embodiment is connected to a supervisory control and data acquisition (SCADA) system 310 and a man machine interface (MMI) system through the communication unit 240. . Through this, the user may remotely control the sealed expansion tank and the automatic pressure control type transformer water cooling system according to the present embodiment.

The first pressure sensor unit 210 and the second pressure sensor unit 220 respectively detect the pressures of the first and second sealed expansion tanks 101 and 102 .

Based on the pressure values detected through the first and second pressure sensor units 210 and 220, the control unit 230 connects components (eg, a cooling tower, valves, pumps, inverters, etc.).

Here, the control unit 230 includes a cooling tower spray pump & fan and cooling water valve control unit 231, a cooling water temperature and cooling tower water level control unit 232, a main control unit 233 (inverter control), a circulating water pressure range setting unit ( 234), and the functions of the make-up water pump control unit 235 may be individually or collectively performed.

The control unit 230 can automatically control (or manually remotely control by a user) the transformer water cooling system according to the present embodiment, and for this, the external communication unit 240 (eg RTU, Remote Terminal Unit) can communicate with the SCADA system 310 of

For example, the state of the transformer water cooling system according to the present embodiment is transmitted to the SCADA system 310 through the communication unit 240 or a user's control command is received from the SCADA system 310 to perform the present embodiment. It is also possible to remotely control the transformer water cooling system according to the

Hereinafter, the control unit 230 will be described separately for each detailed function.

The cooling tower spray pump & fan and cooling water valve controller 231 controls the spray pump & fan and cooling water valve (not shown) inside the cooling tower 16 .

The cooling water temperature and cooling tower spray tank level controller 232 controls the cooling water temperature inside the cooling tower 16 and the water level of the spray tank (not shown).

The main controller 233 controls the replenishment water pump 19 in an inverter manner.

The circulating water pressure range setting unit 234 sets the pressure value of the circulating water circulated through the water circulation pump 11 to a predetermined value (or from a user).

The make-up water pump controller 235 controls the make-up water pump 19 to start at a preset lower limit pressure and stop at a preset upper pressure limit.

Based on the pressure value detected through the first and second pressure sensor units 210 and 220, the preset pressure value, the cooling water temperature, the cooling water level, and the like, the control unit 230 generates a corresponding cooling tower control signal, pump (Example: water circulation pump, replenishment water pump, etc.) control signal and valve (ex: water level control valve, on/off valve, etc.) control signal are output.

Referring to FIGS. 2 and 3 , the operation of the closed expansion tank and the automatic pressure control type transformer water cooling system according to the present embodiment will be described.

The control unit 230 operates the water circulation pump 11 to circulate the sealed water circulation pipe (or the sealed water circulation water system for cooling the transformer) and transfers the water heated in the transformer heat exchanger 13 to the warm header 14 ) and supplied to the cooling tower 16 through the supply header 15. Accordingly, the basic operation of returning the water cooled while passing through the trickle pipe of the cooling tower 16 to the water circulation pump 11 through the return header 17 is the same as the conventional method.

However, in this embodiment, a plurality of closed expansion tanks 101 and 102 are installed in the underground storage tank room, and one of the sealed expansion tanks 102 is connected to a pipe directly supplied from the underground storage tank room to the cooling tower 16, Supplement by injecting nitrogen (or dry air) at +1.5 kgf/cm 2 of the basic pressure (that is, the vertical pressure acting when the water pipe is full of water) into the air cushion in the sealed expansion tank (102) When the water pump 19 is operating, the efficiency of lifting capacity (i.e., the height at which the pump lifts water) is increased, and the water hammer phenomenon (i.e., rapid pressure change of water) caused by contraction, expansion, and pump operation of the pipe increases the efficiency of the pipe. destruction) can be prevented.

Here, the closed expansion tanks 101 and 102 are formed in a structure in which an air layer using an air cushion is formed in the upper part (upper part) of the tank to absorb pressure fluctuations by its elasticity.

The control unit 230 automatically maintains a required constant pressure (+1.0 kgf/cm 2 of the basic pressure) and also starts and stops the make-up water pump 19 using the water pipe pressure sensor 110 to increase efficiency. The speed control (ie, frequency speed control) of a motor (not shown) that automatically drives the make-up water pump 19 is performed according to the monitoring of the change in pressure detected through the.

In addition, supplementary water supply piping (ie, piping that supplies water from a plurality of closed expansion tanks toward the cooling tower) and cooling circulating water piping that circulates through the transformer heat exchanger 13 (ie, piping that supplies water from a plurality of sealed expansion tanks toward the return header) The valves 109 (that is, the valves that stably maintain the cooling circulating water seal system between the piping that supplies water) are composed of a pressure reducing valve, a check valve, a by-pass valve, a strainer, and a valve set consisting of a pressure gauge, etc.) is installed to provide a stable cooling circulating water sealing system by adjusting the pressure corresponding to the drop of the existing elevated water tank (i.e., +0.5kgf/cm2 of the basic pressure) to be supplied. make up

In addition, another sealed expansion tank (101) is connected and installed to the cooling circulation water pipe to increase the lifting capacity and fundamentally prevent air mixing when the water circulation pump (11) is operated, and to prevent water hammer caused by contraction and expansion of the closed system pipe and pump operation. to be able to prevent

The make-up water pump 19 operates two make-up water pumps for supplying water in the elevated water tank of the existing transformer water cooling system in a first and second order method without installing an additional pump, and the control unit 230 (or the main control unit 233 )) through the speed control signal (ie, automatic frequency speed control signal) to start at the lower limit of the set pressure and stop at the upper limit of the set pressure.

The control unit (or main control unit 233) transmits the pressure monitoring results of the plurality of sealed expansion tanks 101 and 102 and the pipe to the SCADA system 310 through the communication unit 240, and in normal operation, the set pressure When the preset upper and lower limits are reached, an operation control signal is output to automatically control the transformer water cooling system (ie, automatically operate), and in the event of a stop (or failure) of the control unit (or main control unit 2330) By forcibly operating the water circulation pump 11 and the make-up water pump 19 through remote control by the SCADA system 310 (ie, remote manual operation), switching to automatic operation at all times and remote manual operation in case of emergency make it possible

In addition, in order to prevent freezing of the make-up water piping for the water supply of the cooling tower (i.e., the part of the piping exposed to the outside air) during the winter season, the valves (103, 112) of the make-up water supply pipe are operated (i.e., 103 → Colse / 112 → Open) By draining the water in the piping and valve, it is converted into a system only for maintaining the cooling circulation water sealing system (or sealed water circulation piping) stably.

As described above, this embodiment solves the problems that may occur in the existing transformer water cooling system using an elevated water tank (eg, valves frozen in winter, cooling water circulation failure due to air mixing in the water circulation pipe, pipe corrosion, etc.) In addition, it is possible to replace the role of the existing elevated water tank through the configuration of a sealed expansion tank, an automatic pressure monitoring control device, and a circulating water sealing valve set in an underground storage tank room that is not affected by the outside temperature. In addition, this embodiment minimizes the valves exposed to the outside air connected to the cooling tower so that there is no damage from freezing in winter, and the heater and valves (i.e., valve set) for keeping warm and responding to malfunctions due to exposure to the outside air can be reduced. has the effect of enhancing In addition, even when automatic control is not possible, it maintains a constant and stable required pressure 365 days a year in a remote controllable state through remote monitoring and increases the reliability of the water cooling system of the transformer by increasing the stability of the water circulation inside the water pipe through a sealed expansion tank. It works.

The present invention has been described above with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments. you will understand the point. Therefore, the technical protection scope of the present invention should be determined by the claims below.

210: first pressure sensor unit 220: second pressure sensor unit
230: control unit
231: Cooling tower spray pump & fan and cooling water valve control unit
232: Cooling water temperature and cooling tower spray tank water level control
233: main control unit 234: circulating water pressure range setting unit
235: replenishment pump control unit 240: communication unit
310: SCADA system 320: MMI system

Claims (1)

The water circulation pump is operated to circulate the transformer cooling circulating water seal system, and the water heated in the heat exchanger of the transformer is supplied to the cooling tower through the warm header and the supply header, and the water cooled while passing through the trickle pipe of the cooling tower is returned. A plurality of sealed expansion tanks installed in the underground water storage tank room of the transformer water cooling system operated by returning to the water circulation pump through a header;
a pipe connected to directly supply water from one of the closed expansion tanks of the underground storage tank to a cooling tower;
first and second pressure sensor units for respectively detecting the pressure of the closed expansion tank;
a control unit that controls a cooling tower, a valve, a pump, and an inverter, which are pipe connection components of the transformer water cooling system, based on the pressure values detected through the first and second pressure sensor units; and
In preparation for the case where automatic control of the transformer water cooling system by the control unit is not possible, status information and control signals for remote control through the linkage of SCADA (supervisory control and data acquisition) system and MMI (Man Machine Interface) system Including; communication unit for transmission;
The control unit,
a cooling tower spray pump & fan and cooling water valve control unit controlling the spray pump & fan and cooling water valve inside the cooling tower;
a cooling water temperature and cooling tower spray tank water level controller for controlling the cooling water temperature inside the cooling tower and the water level of the spray tank;
A main controller controlling the make-up water pump in an inverter manner;
a circulating water pressure range setting unit configured to set a pressure value of circulating water circulated through the water circulation pump; and
A make-up water pump control unit controlling the make-up water pump to start at a preset lower limit pressure and stop at a preset upper pressure limit value;
The closed expansion tank,
In order to increase the efficiency of lifting capacity during operation of the make-up water pump and to prevent contraction, expansion, and water hammer caused by pump operation,
An airtight expansion tank and an automatic pressure control type transformer water cooling system, characterized in that it is formed in a structure that absorbs pressure fluctuations by its elasticity by creating an air layer using a tube at the top of the inside.

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