JP2007218473A - Waste heat-recovering/pressure-reducing device for steam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat-recovering/pressure-reducing device for steam capable of regulating stream pressure supplied from a steam ejector sucking re-evaporated steam with high accuracy, and sucking the re-evaporated steam by the steam ejector with high efficiency. <P>SOLUTION: The steam ejector 3 is disposed at an upper part inside of a re-evaporating tank 1. A plurality of through holes as suction openings are formed on an outer peripheral face of a suction chamber 12 of the steam ejector 3. A steam supply pipe 9 is connected to the steam ejector 3, and a pressure control valve 10 is mounted. The condensed water supplied from a condensed water supply pipe 2 into the re-evaporating tank 1 is partially re-evaporated, and sucked to the suction chambers 12 of the steam ejector 3. The remaining condensed water flows down into a liquid pressure-feed member 7 from a liquid inflow port 15 of the liquid pressure-feed member 7 disposed at a lower part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

 TECHNICAL FIELD The present invention relates to a steam waste heat recovery and decompression device that re-evaporates high-temperature condensate condensed with steam in a re-evaporation tank and reuses it as steam.

 In the conventional steam waste heat recovery and decompression device, a condensate supply pipe is connected to the re-evaporation tank, and a communication pipe is interposed in the steam ejector that sucks the vapor re-evaporated from the condensate in the re-evaporation tank. The re-evaporation tank is connected, and a pressure control valve is attached to this communication pipe. The re-evaporation vapor in the re-evaporation tank is sucked with a steam ejector and supplied to a predetermined steam use location. Waste heat recovery can be achieved.

  The conventional steam waste heat recovery and decompression device has a problem that the pressure of steam supplied from a steam ejector to a predetermined steam use location cannot be adjusted with high accuracy.

In the conventional steam waste heat recovery and decompression device, since the reevaporation tank and the steam ejector are connected via the communication pipe and the pressure control valve, the reevaporation tank is connected to the suction port of the steam ejector. As a result, the pressure loss in the pipes up to this point has increased, and there has been a problem that the re-evaporated vapor generated in the re-evaporation tank cannot be efficiently sucked by the steam ejector.
JP 2004-278871 A

  The problem to be solved is that the steam pressure supplied from the steam ejector that sucks the re-evaporated steam can be accurately adjusted, and the pressure loss from the re-evaporation tank to the suction port of the steam ejector is minimized. Thus, a steam waste heat recovery and decompression device capable of efficiently sucking reevaporated steam with a steam ejector is obtained.

  In the present invention, a condensate supply pipe is connected to a re-evaporation tank, and a steam ejector that sucks vapor re-evaporated from the condensate in the re-evaporation tank is connected, and steam for driving is supplied to the steam ejector. A pressure control valve is attached to the steam supply pipe, and at least the suction port of the steam ejector is opened in the re-evaporation tank.

  In the present invention, by attaching a pressure control valve to the steam supply pipe of the steam ejector, the steam pressure supplied from the steam ejector can be accurately adjusted, and the suction port of the steam ejector is opened in the re-evaporation tank. Thus, the pressure loss between the re-evaporation tank and the suction port of the steam ejector can be made substantially zero, and the re-evaporated vapor can be efficiently sucked by the steam ejector.

  The present invention uses a pressure control valve. If this pressure control valve can control and control the pressure, it is a conventionally known valve, for example, an automatic pressure control valve that combines a pressure sensor and a controller. Or a self-acting pressure control valve or the like can be used.

  In FIG. 1, a re-evaporation tank 1, a condensate supply pipe 2 for supplying condensate to the re-evaporation tank 1, a steam ejector 3 disposed in the re-evaporation tank 1, and a steam supply pipe 9 of the steam ejector 3 are attached. The pressure control valve 10 and the liquid pumping member 7 constitute a steam waste heat recovery and decompression device.

The reevaporation tank 1 has a cylindrical sealed shape, and a condensate supply pipe 2 is connected to the upper part of the right side surface, and a condensate outlet pipe 5 is connected to the lower part of the left side surface. The condensate supply pipe 2 is connected to a condensate generation source such as a steam using device (not shown) through a valve 6 and a steam trap 23. On the other hand, the condensate outlet pipe 5 is connected to the liquid inlet 15 of the liquid pumping member 7 via a check valve 14. The check valve 14 only allows the liquid to flow from the re-evaporation tank 1 to the liquid pumping member 7, and does not allow the liquid to pass in the opposite direction.

A steam ejector 3 is disposed above the inside of the re-evaporation tank 1. A pressure control valve 10 is attached to the steam supply pipe 9 that supplies driving steam to the steam ejector 3. The steam supply pipe 9 is connected to a nozzle portion (not shown) in the suction chamber 12 of the steam ejector 3. A plurality of through holes are provided on the outer peripheral surface of the suction chamber 12 (not shown) to form a suction port. The steam ejector 3 generates a predetermined suction force in the suction chamber 12 by the high-pressure steam supplied from the steam supply pipe 9, and the steam re-evaporated from the condensate in the re-evaporation tank 1 is supplied to the suction chamber 12. It is possible to suck directly from the suction port on the outer peripheral surface.

In the present embodiment, the entire steam ejector 3 is disposed in the reevaporation tank 1 and the through hole of the suction chamber 12 is used as a suction port. The suction port can be formed in a part of the suction port.

The pressure control valve 10 attached to the steam supply pipe 9 uses a pressure sensor 25 attached to the secondary side of the steam supply pipe 9 in combination with a pressure controller (not shown). The pressure in the steam supply pipe 9 is detected by the pressure sensor 25, and the valve opening degree of the pressure control valve 10 is automatically controlled so as to reach the set pressure set by the pressure controller. The pressure of steam supplied from the secondary side to a steam use location (not shown) can be accurately adjusted to an arbitrary value.

A pipe 24 is connected to the upper part of the reevaporation tank 1 and a pressure control valve 4 is attached. The pressure control valve 4 is a self-acting primary pressure control valve. When the pressure in the reevaporation tank 1 exceeds the set pressure of the pressure control valve 4, the pressure control valve 4 is opened and the pressure in the reevaporation tank 1 is increased. By releasing the pressure, the pressure in the reevaporation tank 1 can be maintained at a set value.

The liquid pumping member 7 has a liquid inlet 15 and a liquid outlet 16, a high-pressure operating fluid inlet 17 and a high-pressure operating fluid outlet 18, and condensate is discharged to the liquid outlet 16 via a check valve 19. While connecting the pipe 20, the high-pressure steam pipe 21 is connected to the high-pressure operating fluid inlet 17. On the other hand, the high-pressure operating fluid discharge port 18 communicates with the upper part of the re-evaporation tank 1 through the pressure equalizing pipe 22.

The liquid pumping member 7 is disposed below the reevaporation tank 1. Further, the liquid pumping member 7 closes the high-pressure operating fluid introduction port 17 and opens the high-pressure operating fluid discharge port 18 when a float (not shown) disposed therein is located in the lower portion, and re-evaporation tank From 1, the condensate flows down through the check valve 14 and the liquid inlet 15 into the liquid pumping member 7. When condensate accumulates in the liquid pumping member 7 and a float (not shown) is located at a predetermined upper portion, the high-pressure operation fluid discharge port 18 is closed, while the high-pressure operation fluid introduction port 17 is opened, and the high-pressure steam pipe The steam for high-pressure pumping is caused to flow from 21 to the inside, so that the condensate accumulated therein is pumped to a predetermined location through the liquid outlet 16, the check valve 19 and the condensate discharge pipe 20.

  When the condensate is pumped and the liquid level in the liquid pumping member 7 is lowered, the high pressure operating fluid inlet 17 is closed again and the high pressure operating fluid outlet 18 is opened, so that the condensate is discharged from the liquid inlet 15. Flow down to the inside. By repeating such an operation cycle, the liquid pumping member 7 pumps the condensate from the reevaporation tank 1 to a predetermined location.

A portion of the condensate supplied from the condensate supply pipe 2 into the re-evaporation tank 1 is re-evaporated in the re-evaporation tank 1 and sucked into the suction chamber 12 of the steam ejector 3. In this case, there is no member that obstructs the flow of the re-evaporated vapor to the suction chamber 12 and increases the pressure loss. Therefore, the vapor in the re-evaporation tank 1 is efficiently suctioned with almost no pressure loss. 12 is aspirated.

The pressure control valve 4 attached to the upper line 24 of the reevaporation tank 1 causes the pressure in the reevaporation tank 1 to be a pressure state in which condensate can flow into the reevaporation tank 1 from the steam trap 23. That is, by setting the pressure in the re-evaporation tank 1 to a pressure state lower than the pressure in the condensate supply pipe 2 by a predetermined value, the condensate can surely flow down from the steam trap 23 to the re-evaporation tank 1. it can.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the Example of the waste heat recovery of steam and the pressure reduction device concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Re-evaporation tank 2 Condensate supply pipe 3 Steam ejector 7 Liquid pumping member 9 Steam supply pipe 10 Pressure control valve 14 Check valve 15 Liquid inlet 16 Liquid outlet 17 High pressure operation fluid inlet 18 High pressure operation fluid outlet 20 Water discharge pipe 23 Steam trap 24 Pipe line

Claims (1)

A steam supply pipe that connects a condensate supply pipe to the re-evaporation tank and connects a steam ejector that sucks vapor re-evaporated from the condensate in the re-evaporation tank, and supplies steam for driving to the steam ejector A steam waste heat recovery and decompression device, wherein a pressure control valve is attached to the steam ejector and at least a suction port of the steam ejector is opened in the reevaporation tank.

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