JPS6159169A - Method of discharging noncondensable gas from separate type heat exchange device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for discharging non-condensable gas from a separate heat exchange device, and in particular, to effectively eliminate non-condensable gas that accumulates in a large equipment and affects heat exchange characteristics. It is something that is discharged. [Prior art] Heat exchange equipment using heat pipes that exchange heat through phase transformation due to evaporation and condensation of the working fluid is generally used for the apparent recovery of factory exhaust gas, waste water, etc. Exhaust heat source (heating fluid) and heat utilization section liquid addition P! A fluid)
Depending on the conditions, it is necessary to evaporate and condense the preparation liquid at separate locations, and in such cases a separate heat exchanger is used. As shown in Fig. 5, this device has an evaporation section (1) and a condensation section (2) placed at separate positions, a working fluid tank (3) connected below the condensation section (2), and a working fluid tank (3) connected to the bottom of the condensation section (2). 1) and the condensing section (2) are connected with an insulated pipe (4), and the evaporating section (1) and tank (3) are disconnected]
A circulation circuit is formed by connecting the heat pipes (5), and a working fluid (6) is sealed in the circuit, which is circulated in the direction of the arrow to be heated by the heating fluid (A) in the evaporation section (1). Evaporate the working fluid (6) and distribute the generated steam!
(4), the fluid to be heated (B) is introduced into the condensing section (2).
By cooling and condensing the fluid and flowing down into the tank (3), heat exchange is performed between the heating fluid (A) and the fluid to be heated (B). The working fluid (6) can be circulated naturally depending on the height relationship between the evaporating section (1) and the condensing section (2), or it can be forced to circulate by installing a pump (7) in the piping 5) as shown in the figure. This device applies the principle of a heat pipe, and even if the evaporating section and condensing section are separated, the working fluid and steam can circulate well, and it exhibits excellent heat exchange characteristics.However, actual waste heat recovery is difficult. If non-condensable gas exists in the circuit, it not only obstructs the movement of the working fluid and steam, but also stays in the condensing section and deteriorates the heat exchange characteristics.For example, if non-condensable gas exists in the circuit during operation, air etc. Also, during operation, non-condensable gas (hydrogen in the case of water and iron) may be generated due to the reaction between the hydraulic fluid and equipment materials, and if the circuit is operated under negative pressure, air may be drawn from the flange etc. Therefore, it is necessary to promptly detect 1 liter of non-condensable gas in the condensing section and discharge it at an appropriate timing. Conventionally, a discharge pipe is provided on the downstream side to discharge non-condensable gas. For example, as shown in Fig. 6, a pipe-shaped or chamber-shaped (the figure shows a pipe-shaped case) both upper and lower headers ( A large number of heat exchanger tubes (2C
) to form the C condensing section (2), and attach the upper header (2).
Connect the steam introduction pipe (4) to a) and connect the lower header (
Attach the piping (10) that connects to the tank (3) to 2b), and attach the exhaust pipe (11) with the exhaust valve (12>) to the piping (10).In this way, the piping (4) Steam introduced from the upper header (2a) is passed through each heat exchanger tube (2
C) and is cooled by the heated fluid (B) to form condensed droplets (8) on the inner wall of the heat transfer tube (2C). When this is allowed to flow down, the non-condensable gas (9) becomes a vapor. It stays on the downstream side of the flow, that is, in and below the lower header (2b). Exhaust'! The non-condensable gas (9) is discharged by manually or automatically opening and closing a discharge valve (12) provided at (11). [Problems to be Solved by the Invention] However, as the device becomes larger, the number of heat exchanger tubes in the condensing section also increases, and the header also becomes longer or larger. When you open the pipe (
10) Even after the non-condensable gas (9) has been exhausted from the nearby heat exchanger tubes (2cm6) and (2cm7), the heat exchanger tube (2cm1) is far from the piping (10) even when steam starts to escape.
, (2cm2) (2cm3)..., the non-condensable gas (9) remains. Therefore, although the heat transfer tubes (2cm6) and (2cm7) near the pipe (10) are filled with steam throughout their length and exhibit high heat exchange characteristics, the heat transfer tubes (2cm1) and (2cm2) that are far from the pipe (10) exhibit high heat exchange characteristics. ,(2
cm3>-'P has the disadvantage that the remaining portion of the non-ill Jla gas (9) does not contribute as a heat transfer surface, resulting in a decrease in the heat exchange characteristics of the entire device. [Means for Solving the Problems] In view of this, the present invention has been developed as a result of various studies, and has been developed by installing two or more gas exhaust pipes or piping with gas exhaust pipes at intervals, or/and by installing a non-condensable gas exhaust side. We found that it is effective to install an orifice at the end of the heat exchanger tube and make the orifice diameter smaller the closer it is to the gas exhaust pipe or piping with the gas exhaust pipe.
As a result of further studies, we have developed a method for discharging non-condensable gas from a separate heat exchanger that can effectively discharge non-condensable gas stagnant in large-scale equipment. One of the present inventions is to separately arrange an evaporation section and a condensation section with headers attached to both ends of a large number of heat transfer tubes, connect them with heat insulated piping to form a circulation circuit, and supply the working fluid into the circuit. In a method for discharging non-condensable gas from a device that performs heat exchange through phase transformation of a working fluid by enclosing and circulating it: Two gas discharge pipes or piping with gas discharge pipes are installed in the header on the downstream side of the flow of steam in the condensing section. The pipes are installed at intervals of at least 1,000,000,000, and the non-condensable gas is uniformly discharged from the discharge pipe. Another aspect of the present invention is to attach headers to both ends of a large number of heat transfer tubes, and to separate the evaporation section and condensation section,
In a method for discharging non-condensable gas from a device that connects these with insulated piping to form a circulation circuit, encloses and circulates a working fluid in the circuit, and performs heat exchange through phase transformation of the working fluid, the condensing section is Attach 11 or more gas exhaust pipes or piping with gas exhaust pipes to the header on the downstream side of the steam flow (), provide an orifice at the end of the heat transfer tube attached to the header, and install gas exhaust pipes or piping with gas exhaust pipes. The diameter of the orifice is made smaller as it gets closer to the exhaust pipe to uniformly discharge non-condensable gas from the exhaust pipe. That is, one of the present inventions is as shown in FIG.
A pipe (10) equipped with a gas discharge pipe (11a) is connected to the header (2b) on the downstream side (downward in the figure) of the steam flow of the condensing section (2) where the Install two or more pipes (the figure shows three pipes) at intervals, or install one pipe (10) and two or more pipes (the figure shows three pipes) on the header (2b) as shown in Figure 2. The gas exhaust pipes (11b) are installed at intervals. In this way, each discharge pipe (lla), (11b)
be connected singly or in parallel and connected to the C discharge valve (12), or as shown in the figure, the discharge pipes (11a), (llb
) is connected in parallel with a throttle valve (13), which is then connected to the discharge valve (12). Although not shown in the figure, the steam introduced into the condensing section from the piping is cooled by the heated fluid, and the condensed working fluid (6) is transferred to the piping (10).
) to flow up into the tank, and each evaporator tube (2 cm
1), (2cm2)...(2cmn), the non-condensable gas (9) retained in the chamber is discharged through the discharge valve (12). Another aspect of the present invention is that, as shown in Fig. 3, a large number of heat exchanger tubes <20-1), (2cm2) and (2cmn) are installed on the downstream side of the steam flow of the condensing section (2) (Fig. At least one gas discharge color (11) or gas discharge pipe (=J pipe (10)) is installed in the header (2b) of the lower part (the figure shows a case where there is one pipe with a discharge pipe (10)). Installation, attach to the header (2b) (Puta heat exchanger tube (2cm1), (20-
2) An orifice (14) is provided at the end of the pipe (2O-n), and the hole diameter of the orifice (14) is made smaller as it approaches the discharge pipe (11) or piping with a discharge pipe (10). In this way, although not shown in the figure, the steam introduced into the condensing section from the piping is cooled by the heated fluid, and the condensed working fluid (6) is made to flow down into the tank from the piping (10). 2c
m1>, (2cm2)-(2cmn), the non-condensable gas (9) remaining within the space is discharged from the discharge valve (12). In addition, when two or more discharge pipes or discharge pipes are provided, a throttle valve may be provided in the discharge pipes as in the case of FIG. 1 or FIG. 2. (Function) In this way, a gas exhaust pipe or piping with a gas exhaust pipe is connected to the header on the downstream side of the steam flow. ! Set an interval of 1 or more

[An orifice is installed at the downstream end of the steam flow of the evaporator tube installed in a pipe or/and header, and the hole diameter of the orifice is made smaller as it is closer to the gas exhaust pipe or piping with the gas exhaust pipe. Due to this, some parts of the header are not covered.
Even if the reactive gas remains, it will not remain inside the heat transfer tube,
Shows good heat exchange properties. 2 exhaust pipes or piping with exhaust pipes
If more than one is used, a throttle valve is installed for each discharge color.
It is desirable to equalize the discharge by the discharge valve of ``Ill! For example, the temperature on the upstream and downstream sides of the steam flow in the condensing section is detected using a thermocouple, etc., and if the temperature difference is 2°C or more, it is determined that non-condensable gas has accumulated, and the discharge valve is closed. Either listen to it immediately or open it after a certain period of time. In this case, the pressure inside the condensing part is detected at the same time, and if the pressure is negative, it is forced to discharge using a gas pump, etc., and if it is positive pressure, it is discharged naturally. ] Gas The number of exhaust pipes or piping with gas exhaust pipes is L m, the distance from the inner wall end of the gas exhaust pipe or piping with gas exhaust pipe to the inner wall end of the farthest heat transfer tube, and the inner diameter of the gas exhaust pipe or gas exhaust pipe A' piping. Or the equivalent inner diameter (the value obtained by dividing the cross-sectional area by π in a discharge pipe with a cross-section outside the collection) is D 7
If 1L, then L>0.6+0.8 (D-0,05>), install two or more gas exhaust pipes or gas exhaust pipes with color and color. The orifice installed at the side end may be of any type as long as it has a restricting action, and the closer the orifice is to the gas exhaust pipe or piping with the gas exhaust pipe, the smaller the orifice diameter will be to reduce the flow of steam and non-condensable gas. Uniformization. [Example] Cu heat exchanger tube with diameter 0.05TrL, length 1', 0TrL, CLI header with diameter 0.1m, inner diameter 0.05
The condensing section shown in Table 1 was created using a pipe with a gas exhaust pipe manufactured by CLI. The discharge pipe was connected to the discharge valve via a throttle valve. Table 1 Concerning the steam condensing section As shown in Figure 1, the temperature on the downstream side of the steam flow in each evaporator tube is determined by thermal lightning pairs (15-1) (15-2).
... (15-n), and when the difference between the upstream and downstream temperatures of the steam flow in the heat transfer tube is 2°C or more, it is determined that non-condensable gas has accumulated, and the discharge valve is closed. After listening to this, the remaining gas was discharged, and the temperature changes in the heat transfer tube after the gas was discharged are shown in FIGS. 4(a), (b), and (c). The diagram shows the temperature change with temperature on the vertical axis and the number of heat exchanger tubes on the horizontal axis. Figure (a) shows the case where L is relatively short at 0.55 m, and (1) shows the case with a discharge pipe. The temperature change according to the conventional method when there is one pipe is shown, L < 0.6 + 0.8
([) −0,05> holds, so the temperature difference among all the heat exchanger tubes is within 2° C. by discharging the non-condensable gas through one pipe with a discharge pipe. On the other hand, as shown in the figure, L is 1.2 m long and 1, l > 0.6 + 0.8
(D-0,05), and as shown in (2), with one pipe with a discharge pipe, the heat transfer at the farthest position is 6℃ or more, and the exhaust gas of non-condensable gas is insufficient. It can be seen that However, in the method of the present invention, in which two discharge color/marked tubes are used as shown in (3), or an orifice is attached to the lower end of the heat transfer tube to adjust the hole diameter as shown in (4), all of the heat transfer tubes are It can be seen that the temperature difference is within 2°C. (c) Even if L is as long as 1.87n as shown in the figure, it is not possible to use three pipes with discharge pipes as shown in (5) and (6), or to use two pipes with discharge pipes. , and according to the method of the present invention in which an orifice is provided at the lower end of the heat exchanger tube and the hole (¥) is adjusted, the temperature difference of all the heat exchanger tubes is within 2°C. [Effects of the Invention] As described above, according to the present invention, it is possible to solve the gas residual problem that occurs when non-condensable gas is discharged due to the increase in size of a separate heat exchange device, and improve the heat exchange characteristics of the device. It is something that has a great effect.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the method of the present invention in the condensing section, FIG. 2 is an explanatory diagram showing another example of the method of the present invention in the condensing section, and FIG. 3 is an explanatory diagram showing another example of the method of the present invention in the condensing section. An explanatory diagram showing an example, FIG. 4 (a), (b), and (c) show the effects of the method of the present invention in comparison with the conventional method C1
(A) is small! ! (b) is a comparison diagram of a conventional example of a large-sized device and the method of the present invention, (c) is an example of an even larger device of the present invention, and Fig. 5 is an example of a conventional separate type heat exchange device. FIG. 6 is an explanatory diagram showing an example of a conventional small condensing section in FIG. 5, and FIG. 7 is an explanatory diagram showing an example of a conventional large condensing section. 1... Chobon part, 2... Condensing part, 2a... Upper header, 2b... Lower header, 2c, 2cm1.2cm2. -2cmn-...Heat transfer tube, 3...Tank, 4.5...Insulated piping, 6...Working membrane, 7...Pump, 9...Non-condensable gas, 10...
... Piping, 11, 11a, 11b - ... Gas discharge pipe, 12 ... Discharge valve, 13 ... Throttle valve, 14.
... Oriswiss Figure 5

Claims (4)

[Claims] (1) The evaporating section and the condensing section with headers attached to both ends of a large number of heat transfer tubes are arranged separately, connected by insulated piping to form a circulation circuit, and the working fluid is enclosed and circulated within the circuit. In a method for discharging non-condensable gas from a device that performs heat exchange by phase transformation of a working fluid, two or more gas discharge pipes or piping with gas discharge pipes are installed at intervals in the header on the downstream side of the steam flow in the condensing section. 1. A method for discharging non-condensable gas from a separate heat exchange device, characterized in that the non-condensable gas is discharged from the discharge pipe. (2) A method for discharging non-condensable gas from a separate heat exchanger according to claim 1, wherein a throttle valve is provided in each discharge pipe to equalize the amount of exhaust gas from each discharge pipe. (3) Separately arrange the evaporating section and condensing section with headers attached to both ends of a large number of heat transfer tubes, connect them with insulated piping to form a circulation circuit, and enclose and circulate the working fluid in the circuit. In a method for discharging non-condensable gas from a device that performs heat exchange by phase transformation of a working fluid, one or more gas discharge pipes or piping with gas discharge pipes are attached to the header downstream of the flow of steam in the condensing section, An orifice is provided at the end of the heat exchanger tube attached to the header, and the hole diameter of the orifice is made smaller as it approaches the gas exhaust pipe or the attachment point of the gas exhaust pipe attached pipe, so that non-condensable gas is discharged from the exhaust pipe. Method for discharging non-condensable gas from separate heat exchange equipment. (4) A method for discharging non-condensable gas from a separate heat exchanger according to claim 3, wherein a throttle valve is provided in two or more exhaust pipes to equalize the amount of exhaust gas from each exhaust pipe.