JP4970072B2 - Water-cooled piping system and unit replacement method in water-cooled piping system - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled power system that is used in a water-cooled power conversion device such as a drive device or a converter device having a unit, and includes a water-cooled pipe (base pipe) composed of one system, and a unit replacement method in the water-cooled piping system .

Since a unit for power conversion on which a semiconductor element constituting a large-capacity power conversion device is mounted has a large calorific value, a water cooling method is generally adopted. In general, the cooling pipes of the plurality of units have a pipe structure branched in parallel from the mother pipe in consideration of cooling efficiency. If a pipe configuration branched in parallel is adopted, it is important to balance the flow rate of each pipe. In recent years, techniques for balancing the flow rate without providing a flow meter in individual branch pipes have been proposed. (For example, refer to Patent Document 1).
JP 2005-73400 A (Overall)

  In the water cooling system having the piping configuration disclosed in Patent Document 1, when a specific unit fails, it is necessary to replace the failed unit. However, it is also a big problem to perform this unit replacement smoothly. In particular, even if a plurality of power converters are cooled by a water-cooling system consisting of a single water-cooled mother pipe and a specific unit of one power converter fails, power conversion other than the power converter to which the failed unit belongs The following problems arise when replacing the failed unit while the device continues to operate.

  One of them is a problem that water leakage occurs when an exchange operation is performed with a new healthy unit in a state where water pressure (residual pressure) is applied to the water-cooled piping.

  Secondly, when replacing with a new healthy unit, there is a possibility that the air in the cooling pipe in the unit may move in the mother pipe and adversely affect other healthy power converter units It is.

  The present invention has been made in view of the above-described problems, and its purpose is to prevent water leakage when replacing a unit, and to allow air bleed work online after restoration to a new unit and water-cooled piping. To provide a unit replacement method in a system.

  In order to achieve the above object, a water-cooled piping system according to a first aspect of the present invention is a water-cooled piping system for supplying cooling water in parallel to a plurality of power converters composed of at least one unit. A circulation pump for supplying cooling water via a mother pipe, a surge tank for pressure absorption connected to the mother pipe, and a water supply branch valve at a position branched from the mother pipe, A branch pipe for water supply for supplying water in parallel to each power converter unit, and a drain branch valve provided to recirculate waste water from each power converter unit, and at a position where it joins the mother pipe And a branch pipe for drainage provided, and a branch pipe for maintenance branched from the inflow side of each drainage branch valve and connected to the surge tank via the maintenance valve. .

  The unit replacement method in the water-cooled piping system according to the second aspect of the present invention is configured to supply cooling water in parallel to a plurality of power converters composed of at least one unit via a mother pipe. A circulation pump for supplying cooling water, a surge tank for pressure absorption connected to the mother pipe, and a water supply branch valve that is always open at a position branched from the mother pipe, A branch pipe for water supply for supplying water in parallel to the converter unit, and a drain branch that is provided to recirculate waste water from each of the power converter units and is always open at a position where it joins the mother pipe A branch pipe for drainage provided with a valve, and a branch pipe for maintenance branched from the inflow side of each drainage branch valve and connected to the surge tank via a maintenance valve that is normally closed In the water-cooled piping system provided, when any unit of the power conversion device is replaced, the water supply branch valve and the drainage branch valve for the power conversion device to which the unit belongs are closed and the maintenance valve is opened. It is characterized in that the unit is removed in the state.

  Furthermore, a unit replacement method in a water-cooled piping system according to a third aspect of the present invention is a method for supplying cooling water in parallel to a plurality of power converters composed of at least one unit via a mother pipe. A circulation pump for supplying cooling water, a surge tank for pressure absorption connected to the mother pipe, and a water supply branch valve that is always open at a position branched from the mother pipe, A branch pipe for water supply for supplying water in parallel to the converter unit, and a drain branch that is provided to recirculate waste water from each of the power converter units and is always open at a position where it joins the mother pipe A branch pipe for drainage provided with a valve, and a branch pipe for maintenance branched from the inflow side of each drainage branch valve and connected to the surge tank via a maintenance valve that is normally closed In the water-cooled piping system provided, when any unit of the power conversion device is replaced, the water supply branch valve and the drainage branch valve for the power conversion device to which the unit belongs are closed and the maintenance valve is opened. It is characterized in that the unit is removed in the state.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the unit replacement | exchange method in the water cooling piping system which prevented the water leak at the time of unit replacement | exchange, and was able to carry out the air bleeding work online after restoration to a new unit.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram of a water-cooled piping system according to Embodiment 1 of the present invention.

  The power conversion device 1A includes units 2AU, 2AV, and 2AW using semiconductor switching elements. For example, a DC voltage from a DC power source (not shown) is input and an AC voltage is supplied to a load (not shown). Similarly, the power converter 1B is also composed of units 2BU, 2BV, and 2BW using semiconductor switching elements. For example, a DC voltage from a DC power source (not shown) is input and an AC voltage is supplied to a load (not shown). The two power converters 1A and 1B are normally operated in a normal state. For example, as in the case of a parallel redundant system, even if any one of them fails, the other one is continuously operated.

  The units 2AU, 2AV and 2AW and the units 2BU, 2BV and 2BW of the power conversion devices 1A and 1B are heating elements, but are cooled by exchanging heat with circulating cooling water. The cooling water is supplied from the circulation pump 3 to the water supply main pipe 4, and further branches into water supply branch pipes 6A and 6B provided with water supply branch valves 5A and 5B at the water supply branch portion, respectively. The cooling water further branches from the water supply branch pipes 6A and 6B to the unit branch pipes, thereby passing through the inside of the units 2AU, 2AV and 2AW and the units 2BU, 2BV and 2BW to the drainage branch pipes 7A and 7B, respectively. Each is supplied to join. Then, the cooling water flowing out to the drain branch pipes 7A and 7B joins and returns to the drain main pipe 9 via the drain branch valves 8A and 8B provided in the drain branch parts, respectively, and is not shown in the drawing. After being cooled by the above, it is refluxed to the circulation pump 3.

  Branch pipes are provided on the front side of the drainage branch valves 8A and 8B provided in the drainage branch pipes 7A and 7B, respectively, and each of the branch pipes is maintained via the maintenance valves 10A and 10B. The pipes 11 are respectively connected. The maintenance pipe 11 is connected to a surge tank 12 connected via a branch pipe to the drain side of the circulation pump 3 in order to avoid an increase in water pressure due to an increase in liquid temperature and the like. have. In addition, in FIG. 1, although the maintenance piping 11 is comprised so that the branch pipe from the waste_water | drain side of each power converter device may join, as a structure which provides maintenance piping with respect to each power converter device Also good.

  Each of the units 2AU, 2AV and 2AW and the units 2BU, 2BV and 2BW is provided with a coupler 13 at a portion where a branched water cooling pipe and a cooling pipe in the unit are connected to facilitate unit replacement. In FIG. 1, only the coupler on the drain side of the unit 2AW is shown, and the other couplers are not shown.

  The operation of the present embodiment having the above configuration will be described below.

  Water supply branch valves 5A and 5B provided at positions branching from the main pipe 4 to the power converters 1A and 1B, and drainage branch valves 8A and 8B provided at positions returning from the power converters 1A and 1B to the main pipe 9 again. Both are always open.

  On the other hand, the maintenance valves 10A and 10B provided on the branch pipes joining the drain pipes 7A and 7B of the power converters 1A and 1B to the maintenance pipe 11 are always closed, and the maintenance pipe 11 is normally closed during normal operation. There is no cooling water.

  It is assumed that the lowermost unit 2AW of the power conversion device 1A fails during the normal operation and needs to be replaced.

  First, the water supply branch valve 5A in the water supply branch pipe 6A of the cooling pipe of the power converter 1A and the drainage branch valve 8A in the drainage branch pipe 7A are closed. At this time, the cooling pipe of the power converter 1A is disconnected from the mother pipe 4 and the mother pipe 9, but water pressure is still applied to the cooling pipe in the power converter 1A.

  Next, when the maintenance valve 10A is opened, the cooling water corresponding to the excess pressure flows into the surge tank 12 through the maintenance pipe 11 without being scattered around. As a result, the water pressure in the power conversion device 1A is reduced to a pressure substantially equal to the atmospheric pressure. In this state, the coupler 13 of the unit 2AW is removed. At this time, pump water pressure is not applied to the opening on the cooling branch pipe side of the coupler 13. Therefore, although the water pressure is slightly applied due to a slight head difference, the cooling water is not scattered. Finally, the maintenance valve 10A is closed.

  The procedure for removing the unit 2AW that failed and following the above procedure and attaching the spare new unit 2AW to complete the replacement will be described below. It is assumed that cooling water is not injected into the cooling pipe of the new unit 2AW and that air is contained therein.

  First, the coupler 13 is connected to the new unit 2AW and the new unit 2AW is attached. Next, the maintenance valve 10A is opened, and then the water supply branch valve 5A is opened. When the water supply branch valve 5A is opened, cooling water is poured into the power conversion device 1A from the mother pipe 4 and air in the new unit 2AW is pushed out. The cooling water mixed with air passes through the maintenance valve 10 </ b> A and moves to the surge tank 12.

  When air runs out of the cooling pipe of the power converter 1A, the maintenance valve 10A is closed, and the drainage branch valve 8A is opened to return to the normal operation state as the cooling pipe system. In the above description, the air removal confirmation may be made by visual observation of the surge tank or simply by a timer. Further, if the cooling water is filled in the pipe of the new unit 2AW in advance, the air venting step can be omitted.

  FIG. 2 is a system configuration diagram of a water-cooled piping system according to Embodiment 2 of the present invention.

  About each part of this Example 2, the same part as each part of the system block diagram of the water cooling piping system which concerns on Example 1 of this invention of FIG. 1 is shown with the same code | symbol, and the description is abbreviate | omitted. The difference between the second embodiment and the first embodiment is that the water supply branch valves 5A and 5B are connected to the main pipe 4 side and the drainage branch valves 8A and 8B are connected to the main pipe 9 side by connecting pipes, respectively. This is the point that ball valves 14A and 14B capable of adjusting the flow rate or pressure loss are provided in the pipes, respectively.

  The operation of the second embodiment will be described below.

  The ball valves 14A and 14B are always closed. Consider a case where the unit 2AW of the power conversion apparatus 1A fails in this state and is replaced with a new unit as in the first embodiment.

  First, the ball valve 14A is opened until the pressure loss of the ball valve 14A becomes equal to the pressure loss in the power converter 1A. This work is actually adjusted by looking at the flow meter provided in the ball valve 14A, but it is also possible to adjust automatically.

  Next, the water supply branch valve 5A and the drainage branch valve 8A are closed. The power converter 1A is disconnected from the mother pipe 4 and the mother pipe 9 by these operations, but since there is a bypass route by a bypass connecting pipe passing through the ball valve 14A, the flow rates of the mother pipe 4 and the mother pipe 9 are usually It becomes equivalent to time. Thereafter, the unit 2AW is exchanged by performing the same operation as in the first embodiment. Finally, the water supply branch valve 5A and the drainage branch valve 8A are opened, and then the ball valve 14A is closed.

  By adjusting the ball valve 14A, which is a flow rate adjusting valve as described above, the flow rate of the power conversion device 1B can be kept at the flow rate during normal operation during the replacement operation of the unit 2AW. If it does in this way, it will become possible to prevent the vibration of a piping, cavitation, etc. resulting from a lot of cooling water flowing into power converter 1B.

  In Example 1 and Example 2 demonstrated above, although the power converter device demonstrated by the example of 2 units | sets, it is clear that 3 or more units | sets may be sufficient. Moreover, although the case where the unit which comprises a power converter device is three was demonstrated, the number of units may be arbitrary and may be one, for example.

The system block diagram of the water cooling piping system which concerns on Example 1 of this invention. The system block diagram of the water cooling piping system which concerns on Example 2 of this invention.

Explanation of symbols

1A, 1B Power converter 2AU, 2AV, 2AW, 2BU, 2BV, 2BW Unit 3 Circulating pump 4 Mother pipe 5A, 5B Feed water branch valve 6A, 6B Feed water branch pipe 7A, 7B Drain branch pipe 8A, 8B Drain branch valve 9 Mother Pipe 10A, 10B Maintenance Valve 11 Maintenance Branch Pipe 12 Surge Tank 13 Coupler 14A, 14B Ball Valve

Claims (5)

A water-cooled piping system for supplying cooling water in parallel to a plurality of power converters composed of at least one unit,
A circulation pump for supplying cooling water via the mother pipe;
A surge tank for pressure absorption connected to the mother pipe;
A water supply branch valve is provided at a position branched from the mother pipe, and a water supply branch pipe for supplying water in parallel to each of the units of the power converter,
A branch pipe for drainage provided to return drainage from each power converter unit, and having a drainage branch valve at a position where it joins the mother pipe;
A water-cooled piping system comprising a maintenance branch pipe branched from the inflow side of each drainage branch valve and connected to the surge tank via a maintenance valve. The inflow side of the water supply branch valve for each of the power converters and the outflow side of the drainage branch valve are each connected by a bypass branch pipe,
The water-cooled piping system according to claim 1, wherein a flow rate adjusting valve is provided in each of the bypass branch pipings. In order to supply cooling water in parallel to a plurality of power converters composed of at least one unit,
A circulation pump for supplying cooling water via the mother pipe;
A surge tank for pressure absorption connected to the mother pipe;
A water supply branch valve that is normally open at a position branched from the main pipe, and a water supply branch pipe for supplying water in parallel to each of the power converter units;
A drainage branch pipe provided with a drainage branch valve that is provided to recirculate wastewater from the units of each of the power converters and is normally open at a position where it joins the mother pipe,
A water-cooled piping system comprising a maintenance branch pipe branched from the inflow side of each drainage branch valve and connected to the surge tank via a maintenance valve that is normally closed,
When replacing any unit of the power converter,
Close the water supply branch valve and the drainage branch valve for the power converter to which the unit belongs,
A unit replacement method in a water-cooled piping system, wherein the unit is removed while the maintenance valve is open. In order to supply cooling water in parallel to a plurality of power converters composed of at least one unit,
A circulation pump for supplying cooling water via the mother pipe;
A surge tank for pressure absorption connected to the mother pipe;
A water supply branch valve that is normally open at a position branched from the main pipe, and a water supply branch pipe for supplying water in parallel to each of the power converter units;
A drainage branch pipe provided with a drainage branch valve that is provided to recirculate wastewater from the units of each of the power converters and is normally open at a position where it joins the mother pipe,
A branch pipe for maintenance branched from the inflow side of each drainage branch valve and connected to the surge tank via a maintenance valve that is normally closed,
A water-cooled piping system comprising a bypass connection pipe that connects an inflow side of the water supply branch valve and an outflow side of the drainage branch valve for each power converter via a flow rate adjustment valve that is normally closed. ,
When replacing any unit of the power converter,
Adjust the pressure loss of the piping for the power converter and the pressure loss of the connecting pipe for bypass by operating the valve capable of adjusting the flow rate for the power converter to which the unit belongs,
Close the water supply branch valve and the drainage branch valve for the power converter to which the unit belongs,
A unit replacement method in a water-cooled piping system, wherein the unit is removed while the maintenance valve is open. After removing the unit to be replaced, install a new unit,
With the water supply branch valve for the power converter to which the unit belongs and the maintenance valve open, a new unit is ventilated,
5. The water cooling according to claim 3, wherein the drainage branch valve for the power converter to which the unit belongs is opened, the maintenance valve is closed, and the normal operation is resumed. Unit replacement method in piping system.

Images