JPS62112991A - Heat exchanger and operation thereof - Google Patents

Abstract

PURPOSE:To enhance thermal efficiency and facilitate removing non-condensable gases, by providing a single separate-type heat exchanger with a heat pipe type heat- exchanging system and a heat-transmitting medium circulation type heat-exchanging system, and operating in only one of the two systems according to varied operating conditions. CONSTITUTION:When starting the operation of a heat exchanger, valves 6, 7, 8 are opened, and a feeding pump 9 for a heat-transmitting medium is operated to feed the medium from a tank 10 into a system line. When the level of the medium reaches an uppermost part of a heat-radiating part 2, the pump 9 is stopped, and the valves 6, 7, 8 and a discharge valve 11 are closed. Next, valves 16, 17 are opened, a circulating pump 5 is operated, the medium in the system line is circulated, a high-temperature fluid is passed to a heat-absorbing part 1, while a low-temperature fluid is passed to the heat-radiating part 2, and an operation of the heat-transmitting medium circulation type is thereby performed. In a normal load operation, a valve 15 is opened, the circulating pump 5 is stopped, the valves 16, 17 are closed, while valves 6, 20, 21 are opened, and the pump 9 is operated to drain the medium from the system line. Then, the pump 9 is stopped, the valves 6, 20, 21 are closed, and an operation of the heat pipe type is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention 1 Δ Milk 5 Δ Hole Anal Tilt 1 The present invention provides a separate heat exchanger with a heating medium circulation type heat exchange method, a heating medium circulation type heat exchange method, The present invention also relates to a heat exchanger that converts to a heat pipe type heat exchange system and a method of operating the same.

Ekihiki 1 Separate heat exchangers include a heat medium circulation type exchanger that forcibly circulates the heat medium with a circulation pump, and a heat pipe type heat exchanger that naturally circulates the heat medium through its own evaporation and condensation. There is.

In a heat medium circulation type heat exchanger that is intended to be used as a heat exchanger, there is an inconvenience in that a circulation pump for the heat medium must be constantly operated in the heat exchanger.

In heat pipe type heat exchangers, during low load operation,
There is the inconvenience of a temporary state of reduced thermal efficiency in which the amount of heat exchange between both high and low temperature fluids is insufficient for the amount of heat exchange required by the plant, and furthermore, there is an inconvenience that occurs after the new installation or periodic inspection of the heat exchanger. When starting from a cold open state, or during operation when the pressure of the gas section in the system is around atmospheric pressure or lower,
In order to eliminate the non-condensable gas that accumulates in the heat exchanger system, a bleed ejector is attached, which is inconvenient because it requires a lot of bleed energy, and the operation of the heat exchanger is simple. Not.

There is a need for a means for operating a heat exchanger that solves these problems, has high thermal efficiency, and can easily eliminate non-condensation.

The present invention has been made to meet these 11 full requirements, and its purpose is to separately eliminate non-condensable gas by operating the heat medium circulation type heat exchanger in a system full of liquid. The heat pipe type heat exchanger has the advantage of not requiring any additional means and has good thermal efficiency during low load operation when starting from a cold state, and the advantage that the heat pipe type heat exchanger does not require a heat medium circulation pump during heat exchange. It is an object of the present invention to provide an operating means for converting a separation type heat exchanger into a heat medium circulation type heat exchange method or a heat pipe type heat exchange method in response to changes in the operating conditions by using the method in combination.

[Configuration of the invention 1 1! A heat medium is built into the system in which the heat medium circulates in a separate heat exchanger designed to be operated primarily as a heat pipe type heat exchange system under normal load operating conditions. If the heating medium is not in use, the heating medium is stored in a heating medium tank that is installed outside the heating medium circulation system, and is preheated via a room temperature heating medium or a preheater installed outside the heating medium circulation system. By operating a transport pump installed in a transport piping route that transports the heat medium outside the system, the heat medium is transferred to a lower part of the system, preferably a heat exchanger (hereinafter referred to as a heat absorption section). It is sent into the system from the lowest point.

If the system is filled with heat medium and the heat medium is released from the atmosphere outlet at the highest point in the system, preferably the highest point of the heat exchanger (hereinafter referred to as heat radiator), the non-heating medium in the system will be released. This indicates that the condensed gas has been removed from the system, so stop the transport pump and close the atmospheric outlet.

Next, the heat medium in the system is circulated by the operation of the bypass pipe E1 circulation pump connected to the communication pipe that circulates the heat medium, and both high and low temperature fluids for heat exchange are distributed to the heat absorption part and the heat radiation part. By doing so, the separation type heat exchanger is operated as a heat medium circulation type heat exchange system.

Even if the separate type exchanger exits the low-load operating state, which occurs when starting from a cold state, while operating in the heat medium circulation type heat exchange method, and the heat exchanger is operated in the B-1 pipe type conversion method. When the normal load operating state is approached, where low thermal efficiency does not occur, the circulation pump is stopped and the heat medium that was circulating in the system is transferred to a low part of the system, preferably the lowest part of the heat absorption part. The heat medium is extracted from the system through a transport piping route that is outside the system and transports heat and medium, and is returned to the heat medium tank to lower the liquid level of the heat medium in the system to a certain level.
By stopping the transport pump, the separation type heat exchanger is operated as a heat pipe type heat exchange system.

The heat medium is built in at a certain level in the system in which the heat medium circulates in the separation type heat exchanger, and the pressure of the gas part in the system is below atmospheric pressure, and the heat exchanger is used as a heat pipe type heat exchanger. If the multiple temperature sensors connected to the heat dissipation section detect that non-condensed gas has accumulated in the upper part of the heat dissipation section when operating as an exchange method, the heat medium tank will release room-temperature gas. By operating a transport pump, the heating medium or preheated heating medium is introduced into the system from a lower part of the system, preferably from the lowest part of the heat absorption section.

If the amount of heat medium in the system increases and the compound gauge connected to the heat radiator shows a pressure higher than atmospheric pressure, open the atmospheric release port at the highest point in the system, preferably at the highest point of the heat radiator. If gas phase and/or liquid phase heating medium is released from the atmosphere discharge port, it indicates that the non-condensable gas in the system has been removed from the system. Close the outlet.

Next, if the heat exchange amount between the high and low temperature fluids is insufficient for the heat exchange amount required by the plant, and the thermal efficiency is reduced, after confirming that the system is full of liquid, the transfer pump is stopped, the heat medium in the system is circulated by operating the circulation pump, and the separation type heat exchanger is operated as a heat medium circulation type heat exchange system. Once the thermal efficiency is restored, the heat exchanger can be converted from a heat medium circulation type heat exchange system to a heat pipe type heat exchange system by extracting the heat medium in the system to the outside of the system using the same method as described above. drive.

In addition, if the thermal efficiency within the system is not in a state where the thermal efficiency has decreased, the heating medium can be extracted from the system by restarting the stopped transport pump in succession to the above-mentioned operation to close the air outlet. The liquid level of the heating medium in J: was lowered to a certain level, and the transport pump was stopped.Then, the separation type heat exchanger was immediately returned to the heat pipe type heat exchange method before non-condensable gas was removed, and operation was started. do.

The gas-liquid mixture discharged outside the system from the atmosphere discharge outlet is separated by a gas-liquid separator connected to the atmosphere discharge outlet, the gas is discharged into the atmosphere, and the liquid is sent to the heat medium tank through the downcomer pipe. will be returned to.

X1 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The figure shows a separate heat exchanger 70- when operated as a heat medium circulation type heat exchange system or a heat pipe type heat exchange system.

An example will be given of means for converting the operating method between the heat medium circulation heat exchange method and the heat pipe heat exchange method in accordance with the operating conditions of the separation type heat exchanger.

Example 1 From the cold state after new installation and periodic inspection of a separate heat exchanger,
When the heat exchanger is put into operation, a heating medium consisting of a heat absorption part 1, a heat radiation part 2, a communication pipe 3 that connects the two parts to circulate the heat medium, and a circulation pump 5 with a bypass pipe line 4 is used. The entire circulation system is filled with air. It should be noted that in the heating medium circulation system, there is no so-called dead-end space where, when warm non-condensable gas in the system is pushed by the heating medium, it cannot be moved from the place where it stays.

In order to completely remove the air filling the system from the system, by operating the lowest pump 9 of the heat absorption section 1 of the separate heat exchanger, the heat medium tank 104jb naf)*W
t ji%aJMM to 99-1・”11”If it doesn’t meet 71 degrees, it’s one! - On the other hand, the air filling the system is pushed out and released into the atmosphere through the gas-liquid separator 12 from the release valve 11 connected to the highest part of the heat radiating part 2 of the heat exchanger. released into the atmosphere. The level of heat medium is at heat radiation part 2
When the temperature reaches the highest point and the heat medium starts to be released from the release valve 11, the transport pump 9 is stopped and the valves 6.7.8 and the release valve 11 are closed.

The heating medium discharged from the discharge valve 11 descends through a downcomer pipe 14 connected to the gas-liquid separator 12 and is returned to the heating medium tank 10.

Next, the valves 16 and 17 are opened, the circulation pump 5 is operated, and the valve 15 of the bypass pipe 4 is closed to circulate the heat medium in the system, and the high temperature fluid is circulated through the heat absorption part 1 as shown by the arrow 18. death,
By flowing the low temperature fluid through the heat radiation part 2 as shown by the arrow 19, heat exchange between the high and low temperature fluids is performed as a heat medium circulation heat exchange system during low load operation at the time of startup of the separation type heat exchanger.

15 to stop the circulation pump 5, close the valves 16 and 17, and extract the heating medium out of the system.
．． 21 is opened and the transport pump 9 is operated, the heat medium is extracted from the system to the heat medium tank 10, the heat medium in the system is reduced, and it is determined by known means (not shown) that the heat medium in the system has decreased to a certain level. If confirmed, stop the transport pump 9,
By closing the valves 6, 20 and 21, the heat exchanger is operated as a heat pipe type heat exchange system.

Example 2 After operating a separation type heat exchanger as a heat pipe type heat exchange method, when the heat exchanger is shut down in 1 (period) and put into operation again from a cold state after a long-term suspension, valve 6,7
．． 11 and operating the transport pump 9,
When the heating medium is introduced into the system, the amount of heating medium in the system is increased, and it is confirmed by known means (not shown) that the system is filled with the heating medium, the transport pump 9 is stopped and the valves 6, 7.8 121 times, open valves 16 and 17, operate circulation pump 5, and open valve 1.
Close 5;, ゛＼ ,, ):, +j The heat load on the separate heat exchanger increases, and even if the heat exchanger is operated using the heat pipe type heat exchange method, a decrease in thermal efficiency occurs. If the normal load is close to the normal load, valve 1
5, the circulation pump 5 is stopped, the valves 16.17 are closed, the valves 6 and 20.21 are opened, and the transport pump 9 is operated, thereby extracting the heat medium from the system to the heat medium tank 10. , after reducing the heat medium in the system and confirming that it has fallen to a certain level, the transport pump 9 is stopped and the valves 6 and 20 are closed.
．． By closing 21, the heat exchanger is operated as a heat pipe type heat exchange system.

Example 3 During operation of a separation type heat exchanger as a heat pipe type heat exchange method, hydrogen liberated from the system inner wall material of the heat exchanger due to a chemical change is sequentially transferred to the upper part of the heat dissipation section 2 located at a high place in the system. When it accumulates, it reduces the condensation efficiency of the heat absorption section, which in turn reduces the thermal efficiency of the heat exchanger.

Connected to the heat radiating part 2 in order to completely eliminate non-condensable gas that has accumulated in the upper part of the heat radiating part 2 from the system when the separate heat exchanger is operating when the pressure of the gas part in the system is near atmospheric pressure or lower. When the plurality of temperature sensors 22 indicate that non-condensable gas is accumulated, the heat medium is removed from the heat medium tank 10 by opening the valves 6, 7.8 and operating the transport pump 9. into the system. The heating medium rises from filling the system and raises the pressure within the system by -1-. When the coupled d123 connected to the non-condensable gas storage/retention section shows a pressure higher than atmospheric pressure, the discharge valve 11 is opened and the non-condensable gas is released into the atmosphere through the gas-liquid separator 12 through the atmospheric discharge pipe 13. Once the gas phase and/or liquid phase heating medium is released from the release valve 11, the release valve 11 is closed.

Next, the inside of the separate heat exchanger system is appropriately cooled by feeding the heat medium, and the thermal efficiency temporarily decreases because the amount of heat exchange between the high and low temperature fluids is insufficient for the amount of heat exchange required by the plant. If this occurs, after confirming that the system is full of liquid, stop the transport pump 9, close the valves 6 and 7.8, open the valve 16.17, and turn on the circulation pump 5. drive, valve 1
By closing 5 and circulating the heat medium in the system,
The heat exchanger is operated as a heat medium circulation type heat exchange system.

In addition, if the system of the separation type heat exchanger is not in a state where the thermal efficiency has decreased, the transport pump 9 is stopped and the valves 7 and 8 are stopped.
The heat medium is removed from the system by closing the heat medium tank 1, opening the valve 20.21 and then restarting the transfer pump 9.
0, reduce the heat medium in the system, lower it to a certain level, stop the transport pump 9, and close the valves 6, 20, 21.
Of course, it is also possible to operate the heat exchanger as a heat pipe heat exchange system by immediately returning it to its original operating state without using it as a heat medium circulation heat exchange system. be.

Example 4 While operating the separation type heat exchanger in a state where the thermal efficiency was reduced as described in Example 3 as a heat medium circulation type heat exchange method, the operating conditions of the heat exchanger were restored to a state close to the normal load. If so, the heat medium is removed from the system by opening the valve 15, stopping the circulation pump 18, closing the valves 16 and 17, opening the valves 6 and 20, and operating the transport pump 9. tank 10
After confirming that the heat medium in the system has decreased to a certain level, the transport pump 9 is stopped and the valve 6 is removed.
By closing 20.21, the heat exchanger is operated as a heat pipe type heat exchange system.

101 Example 5 Operation conditions of a separate heat exchanger (4 under continuous high load condition,
When the heat exchanger is operated as a heat pipe type heat exchange system, if the heat load suddenly changes and the operation becomes a low load operation state, and a decrease in thermal efficiency occurs, the valves 6 and 7.8 are opened and the transport pump 9 is operated. By doing so, the heat medium is sent into the system from the heat medium tank 10. After confirming that the system is full of liquid, stop the transport pump 9, close valves G and 7.8, and close valve 1.
．． 6.17 is opened, the circulation pump 5 is operated, and the valve 15 is closed to circulate the heat medium in the system, thereby operating the heat exchanger as a heat medium circulation type heat exchange system.

When the decreased thermal efficiency of the separate heat exchanger is restored, valve 15 is opened, circulation pump 18 is stopped, and valve 16.1 is closed.
7 is closed and valves 6, 20.21 are opened and the transport pump 9
By operating the system, the heat medium is extracted from the system to the heat medium tank 10, the heat medium in the system is reduced, and when it is confirmed that the amount has decreased to a certain level, the transport pump 9 is stopped,
By closing the valves 6, 20 and 21, the heat exchanger is operated as a heat pipe type heat exchange system.

For each of the above embodiments, the operation conversion means between the same heat exchange systems has been explained, but furthermore, in each embodiment,
The transport pump 9 and the circulation pump 5 are appropriately arranged with piping routes connected to each pump and valves attached thereto,
By switching, the transport pump can be used as a circulation pump, the circulation pump can be used as a transport pump, or it can be replaced with a single pump that has both transport and circulation functions. It is possible to implement the conversion means manually or automatically, and if the preheater 24 for preheating the heat medium is installed outside the heat medium circulation system of the separate heat exchanger, the heat medium tank 10 The heating medium introduced into the system may or may not be preheated.

[Effects of the Invention] According to the present invention, during low load operation at the time of starting up in a cold state such as when a separate heat exchanger is newly installed, periodically inspected, or after a long-term suspension of operation, or a state where thermal efficiency is reduced during operation. In,
I decided to convert the heat exchange method of the heat exchanger from a heat-vib type heat exchange system to a heat medium circulation type heat exchange system.
) has the advantage that the heat medium circulation type heat exchange method has good thermal efficiency during low load operation, and the heat pipe type heat exchange method has the advantage that it has better thermal efficiency than the heat medium circulation type heat exchange method during normal load operation, and By combining the advantages of not requiring a circulation means using a circulation pump with the +B- separation type heat exchanger, it is possible to handle fluctuating operating conditions better than when the heat exchanger is operated using only each heat exchange method. also improves thermal efficiency.
1- It is possible to eliminate non-condensable gas in a system with a pressure below near atmospheric pressure by simply adopting a heating medium circulation type heat exchange method without requiring a separate non-condensable gas removal means such as a bleed ejector. By eliminating the gas and simplifying the non-condensable gas elimination means, one pump can have both FPI functions as a transport pump and a circulation pump.
From these comprehensive effects, it becomes possible to make the heat exchange means economical.

Furthermore, by preheating the heat = 19= medium to be sent into the system of the separate heat exchanger outside the system to a temperature suitable for the operating condition of the heat exchanger, it is possible to prevent the heat from being preheated. It reduces or prevents the temporary decrease in the thermal efficiency of the heat exchanger that occurs when the heat exchanger is heated, and also prevents the unsteady state that occurs due to the temporary decrease in thermal efficiency from affecting related plants. It becomes possible to reduce or prevent this.

[Brief explanation of drawings]

The figure is a diagram showing 70- of the separation type heat exchanger of the present invention. Incidentally, the symbols of the main parts in the figure are as follows. 1... Heat absorption part, 2... Heat radiation part, 3... Communication pipe, 4
...Bypass pipe line, 5...Circulation pump, 6,7.8
... Valve, 9... Transport pump, 10... Heat medium tank, 11... Release valve, 12... Gas-liquid separator, 13...
・Atmospheric discharge pipe, 14...Downfall pipe, 15゜16.17・
...Valve, 18.19...Arrow, 20.21...Valve,
22...Temperature detector, 23...Compound meter, 24...
Preheater.

Claims (12)

[Claims] (1) In a separate heat exchanger consisting of a heat-absorbing cross-exchange device, a heat-radiating cross-exchange device, and a communication pipe that connects both devices and circulates a heat medium, depending on the operating conditions of the heat exchanger, It has a device that converts the heat exchange method to a heat medium circulation type heat exchange method in which a liquid phase heat medium is circulated by a circulation pump, or a heat pipe type heat exchange method in which a gas phase and liquid phase heat medium are naturally circulated. A heat exchanger characterized by: (2) A device for converting to a heat medium circulation type heat exchange system or a heat pipe type heat exchange system is connected to a heat transfer exchange device, which includes a heat medium transport piping route, a transport pump, and a heat medium tank;
It is characterized by an atmospheric discharge port, a temperature sensor, a compound gauge, a gas-liquid separator, which are connected to a heat exchanger, a circulation pump with a bypass pipe, and a downcomer pipe, which are connected to a communication pipe. A heat exchanger according to claim 1. (3) The heat exchanger according to claim 1 or 2, wherein the transport pump and the circulation pump are dual-purpose pumps having the functions of both pumps. (4) A device for converting to a heat medium circulation type heat exchange system or a heat pipe type heat exchange system is installed outside the heat medium circulation system of the separate heat exchanger and is connected to the heat exchanger. 4. The heat exchanger according to claim 1, further comprising a preheater for preheating a heating medium. (5) In a separate heat exchanger consisting of a heat exchanger, a heat radiation exchanger, and a communication pipe that connects the two devices and circulates a heat medium, depending on the operating conditions of the heat exchanger, It is characterized by converting the heat exchange method to a heat medium circulation type heat exchange method in which a liquid phase heat medium is circulated by a circulation pump, or a heat pipe type heat exchange method in which a heat medium in a gas phase and a liquid phase is naturally circulated. How to operate a heat exchanger. (6) Since there is no heat medium built into the system of a separate heat exchanger, the non-condensable gas remaining in the system is removed from the system by filling the system with liquid phase heat medium. The above-mentioned patent is characterized in that after the heat exchanger is operated in a heat medium circulation type heat exchange system, a part of the heat medium is extracted from the system, and the heat exchanger is operated in a heat pipe type heat exchange system. A method of operating a heat exchanger according to claim 5. (7) A heat medium is built into the system of a separate heat exchanger at a certain level, and from a cold state that has been stopped for a long time, the non-condensable gas that remains in the system is transferred to the liquid phase heat in the system. After the heat exchanger is operated in a heat medium circulation type heat exchange system, a part of the heat medium is extracted outside the system, and the heat exchanger is operated in a heat pipe type heat exchange system. 6. The method of operating a heat exchanger according to claim 5, characterized in that the heat exchanger is operated in accordance with the method described in claim 5. (8) After the system of a separate heat exchanger is filled with heat medium and the heat exchanger is operated in a heat medium circulation type heat exchange system from a cold state that has been stopped for a long time, the heat medium is 6. The method of operating a heat exchanger according to claim 5, wherein a portion of the heat exchanger is extracted from the system and the heat exchanger is operated in a heat pipe type heat exchange system. (9) A heat medium is built-in at a certain level in the system of a separate heat exchanger, and the heat exchanger is operated using a heat pipe type heat exchange method when the pressure of the gas part in the system is below atmospheric pressure. The non-condensable gas remaining in the system is removed from the system by filling the system with a gas-phase and/or liquid-phase heating medium, and then the system is filled with a liquid-phase heating medium. After the heat exchanger is operated in a heat medium circulation type heat exchange system, a part of the heat medium is extracted from the system, and the heat exchanger is operated in a heat pipe type heat exchange system. A method for operating a heat exchanger according to claim 5. (10) Claims 5 to 9 above characterized in that the heat medium preheated by a preheater located outside the system of the separate heat exchanger is sent into the system by a transport pump. How to operate the heat exchanger described. (11) The heat medium transport pump is used as a heat medium circulation pump,
Alternatively, the method for operating a heat exchanger according to any one of claims 5 to 10, characterized in that the circulation pump is used as a transport pump and each pump is used for both purposes. (12) The method of operating a heat exchanger according to any one of claims 5 to 10, characterized in that one pump is used as a heat medium transport pump or a heat medium circulation pump.