JP2009041873A - Heat exchanging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanging device performing efficient heat exchange by forcibly circulating a part of vapor to a heat exchanger without using a vapor ejector. <P>SOLUTION: A vapor supply tube 2 and a fluid discharge tube 3 are connected with the heat exchanger 1. A control valve 7 and a vapor flowmeter 8 are disposed on the vapor supply tube 2. The fluid discharge tube 3 is branched to be connected with a condensate discharge tube 11 and a circulation pipe conduit 12. The circulation pipe conduit 12 is provided with a gas-liquid separator 5, an electric vapor circulating means 4 and a vapor flowmeter 14, and connected with the vapor supply tube 2. The vapor is controlled by the control valve 7 when the amount of vapor necessary in the heat exchanger 1 is small, and controlled by the electric vapor circulating means 4 when the amount of vapor is much. A part of the vapor supplied from the vapor supply tube 2 to the heat exchanger 1 is condensed to be the condensate, which is mixed with a part of the vapor to be the mixed fluid, and flows down into the fluid discharge tube 3. The vapor of the condensate separated by the gas-liquid separator 5 of the circulation pipe conduit 12 is forcibly circulated from the electric vapor circulating means 4 into the heat exchanger 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchange apparatus that heats an object to be heated in a heat exchanger using steam as a heat source.

  The heat exchange device connects the steam supply pipe and the fluid discharge pipe to the heat exchanger, discharges the condensate condensed with the heat by heat exchange in the heat exchanger from the fluid discharge pipe, and passes through the fluid discharge pipe. A part of the steam is circulated again to the heat exchanger by the steam ejector.

In the heat exchange apparatus using this steam ejector, when the steam consumption in the heat exchanger fluctuates, there is a problem that the pressure and temperature of the steam in the heat exchanger fluctuate greatly. Usually, there is a predetermined relationship between the drive steam amount and the suction fluid amount of the steam ejector, and a predetermined amount of drive steam is required to secure a certain amount of suction fluid. When the steam consumption of the heat exchanger falls below, the steam pressure and temperature in the heat exchanger will fluctuate greatly.
JP-A-2-213601

  The problem to be solved is to provide a heat exchange device that can circulate a part of steam to a heat exchanger without using a steam ejector that causes fluctuations in steam pressure and temperature.

  The present invention connects a steam supply pipe and a fluid discharge pipe to a heat exchanger, performs heat exchange with steam supplied from the steam supply pipe via a control valve, and condensate condensed with steam by heat exchange. An electric steam circulation means for circulating the steam is attached to the fluid discharge pipe in order to circulate a part of the steam to the heat exchanger through the fluid discharge pipe while discharging to the outside from the fluid discharge pipe, and the steam supply pipe Or, install a steam flow meter that can measure the amount of steam that passes through the fluid discharge pipe so that the overall heat transfer coefficient becomes the maximum value from the relationship between the measured value of the steam flow meter and the overall heat transfer coefficient. A control unit for controlling the electric steam circulation means is provided, and the steam amount necessary for heat exchange is controlled up to a predetermined value by a control valve attached to the steam supply pipe, and when the steam amount exceeds the predetermined value, the electric steam circulation means It is something to control.

  In the heat exchange device of the present invention, by attaching the electric steam circulation means to the fluid discharge pipe, a part of the steam can be circulated into the heat exchanger by the electric steam circulation means. Further, by attaching a steam flow meter and controlling the electric steam circulation means so that the overall heat transfer coefficient becomes the maximum value, it is possible to efficiently exchange the heat of each heat exchanger.

  In the present invention, an electric steam circulation means is attached. As this electric steam circulation means, those conventionally used such as a steam blower and a steam compressor can be used.

  FIG. 1 is a block diagram of an embodiment of the present invention, in which heat is exchanged between a heat exchanger 1, a steam supply pipe 2, a fluid discharge pipe 3, an electric steam circulation means 4, and steam flow meters 8 and 14. Configure the device.

  A steam supply pipe 2 for supplying steam for heating to the heat exchanger 1 is supplied with a control valve 7 for controlling the amount of steam supplied, a steam flow meter 8 for measuring the amount of steam supplied, and It connects with the inlet 9 of the heat exchanger 1 via the pressure sensor 6 which detects the pressure of the vapor | steam.

  A part of the steam supplied from the steam supply pipe 2 into the heat exchanger 1 becomes condensed water by heating and condensing an object to be heated (not shown), and a mixed fluid of the condensed water and a part of the steam is a fluid. It flows down in the discharge pipe 3.

A fluid discharge pipe 3 is branched and a steam trap 10 is attached to one side to form a condensate discharge pipe 11, and a gas-liquid separator 5, electric steam circulation means 4 and a steam flow meter 14 are attached to the other to form a circulation line 12. . The upper end of the circulation line 12 is connected to the steam supply pipe 2. In addition, a control valve 13 for controlling the amount of steam circulated is attached to the circulation line 12.

The gas-liquid separator 5 uses the difference between the masses of steam and condensate to separate them, and can discharge only the condensate separated from the built-in steam trap to the outside. Moreover, the electric steam circulation means 4 shows the example using what combined the electric motor 15 and the steam blower 16 in the present Example. That is, the steam in the circulation line 12 can be supplied to the steam supply pipe 2 via the flow meter 14 by the rotation of the steam blower 16.

Part of the condensate / steam mixed fluid flowing down the fluid discharge pipe 3 reaches the steam trap 10 from the condensate discharge pipe 11 and only the condensate is discharged to the outside, and the remainder of the mixed fluid is discharged from the circulation line 12. Steam and condensate are separated while flowing down the liquid separator 5, and the separated condensate is discharged to the outside from a steam trap provided in the gas-liquid separator 5 and only the separated steam is recovered. Is sucked into the electric steam circulation means 4, further passes through the steam flow meter 14, is mixed with the steam in the steam supply pipe 2, and is supplied to the heat exchanger 1.

  Thus, by forcibly circulating a part of the steam in the heat exchanger 1 through the circulation line 12, heat transfer from the heated steam to the object to be heated in the heat exchanger 1 is promoted. The object to be heated can be efficiently heated. For example, compared with the case where only the condensate is discharged to the outside through the condensate discharge pipe 11 and the steam trap 10, the case where the partial circulation of the steam is forcedly circulated from the circulation pipe 12 is the overall heat transfer coefficient. Can be increased by about 1.5 to 3 times.

  The steam flow meter 8 measures the amount of steam supplied from the steam supply pipe 2 to the heat exchanger 1, while the steam flow meter 14 measures the amount of steam circulated from the circulation line 12 to the heat exchanger 1. There is a relationship shown in FIG. 2 between the measured value of the steam flow meter 8 or 14 and the overall heat transfer coefficient in the heat exchanger 1. That is, in heat exchanger A, the overall heat transfer coefficient has the highest value at the steam flow rate Q1, while in heat exchanger B, the overall heat transfer coefficient has the highest value at the steam flow rate Q2.

The relationship shown in FIG. 2 is stored in a control unit (not shown), and the amount of steam supplied from the electric steam circulation means 4 is set so that the overall heat transfer coefficient becomes the maximum value according to the type of the heat exchanger 1, or The amount of heat required for the heat exchanger 1 can be supplied with the highest overall heat transfer coefficient by appropriately controlling the amount of steam supplied from the control valve 7 of the steam supply pipe 2. When the amount of steam supplied from the steam supply pipe 2 is constant, the flow meter 8 is not necessary, and when the amount of passing steam can be arbitrarily controlled by the steam blower 16, the flow meter 14 is not necessary. .

  When the amount of heat required for heat exchange changes from zero to the maximum value: MAX, as shown in FIG. 3, the steam flow is controlled by the control valve 7 until the steam amount reaches a predetermined value: V1, and the steam amount exceeds V1. By controlling the electric steam up to V2 with the electric steam circulation means 4, even if the required steam amount changes from a small flow rate to a large flow rate, it is possible to supply the steam while reliably following the change.

 In the present embodiment, the steam can be forcibly circulated to the heat exchanger 1 by the electric steam circulation means 4 without using a steam ejector that causes fluctuations in steam pressure and temperature, and the heating efficiency of the heat exchanger 1 Can be increased.

The block diagram which shows the Example of the heat exchange apparatus of this invention. The relationship figure of the general heat-transfer coefficient and steam flow rate of the heat exchange apparatus of this invention. The relationship figure of required heat quantity and steam flow rate of the heat exchange apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Steam supply pipe 3 Fluid discharge pipe 4 Electric steam circulation means 5 Gas-liquid separator 7 Control valve 8 Steam flow meter 11 Condensate discharge pipe 12 Circulation line 14 Steam flow meter 15 Electric motor 16 Steam blower

Claims (1)

A steam supply pipe and a fluid discharge pipe are connected to the heat exchanger, and heat exchange is performed with the steam supplied from the steam supply pipe through the control valve, and condensate condensed by the heat exchange is discharged from the fluid discharge pipe. An electric steam circulating means for circulating the steam is attached to the fluid discharge pipe in order to circulate a part of the steam to the heat exchanger via the fluid discharge pipe while discharging to the outside, and the steam supply pipe or the fluid discharge pipe A steam flow meter that can measure the amount of steam passing through is installed, and the electric steam circulation means is set so that the overall heat transfer coefficient becomes the maximum value from the relationship between the measured value of the steam flow meter and the overall heat transfer coefficient. And a control valve attached to the steam supply pipe until the steam amount necessary for heat exchange reaches a predetermined value, and when the steam amount exceeds a predetermined value, the electric steam circulating means controls the steam amount. Features heat exchanger

Images