JPS6324382Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a heat exchange device, and particularly to a heat exchange device using a separate heat pipe.

There are various types of heat exchange devices that exchange heat between two fluids with different temperatures. Among these, heat pipes transfer heat by evaporating and condensing an enclosed working medium. Several types of heat pipes using this heat pipe as an element of a heat exchange device have been proposed because it provides very good heat transfer in the range. Among this type of heat exchange devices, the inventors proposed a separate heat pipe type heat exchanger in which an evaporating section and a condensing section are separated and connected through a pipe line. In this case, as shown in FIG. 1, if the evaporator tube group 4, which is the heat inflow part, is arranged below and the condensation tube group 8, which is the heat outflow part, is arranged above, the working medium vapor 16 generated in the evaporator tube group 4 will be transferred to the condensation tube group. 8, the working medium liquid 17 condensed in the condenser tube group 8 descends toward the evaporator tube group 4, and the working medium as a whole can naturally circulate between these tube groups. However, depending on the installation conditions of the device, it is not always possible to arrange them in this way, and the evaporator tube group may be located above the condenser tube group. In this case, unless some means is used to forcefully circulate the working medium, circulation will not take place and heat exchange will become impossible.

FIG. 2 shows an example of this forced circulation type heat exchange device. The working medium evaporator 16 heated and evaporated by the heating fluid in the evaporator tube group 4 arranged in the high temperature fluid passage 1 is arranged in the heated fluid passage 2 via the upper header 5 and the steam communication pipe 6 connecting the upper headers. The heat flows into the condensing tube group 8, where it radiates heat and condenses. 7 is an upper header of the condensing tube group 8. The condensed liquid 17 flows into the bubble generator 11 through the lower header 9 and a liquid communication pipe 10 connecting the lower headers. This bubble generator is a kind of bubble pump, which generates bubbles in the condensate by heat 18 supplied from the outside. As a result, the condensed liquid rises in the liquid lift pipe 12 due to the upward force of the bubbles, and reaches the gas-liquid separator 13. The separated liquid flows into the evaporation tube group 4 via the liquid communication tube 10 and the lower header 3. On the other hand, the separated vapor (bubbles) flows into the pipe line 16 via the vapor relief pipe 15 and joins with the vapor discharged from the evaporation pipe group 4. With such a configuration, the working medium is forced to circulate and flow. Here, the reason why a bubble generator is used as a forced circulation pump is that the structure is simple, and the bubbles themselves generated by heat supplied from the outside have latent heat.
This is because it can be used as a heat source for heating the fluid to be heated. However, this bubble generator naturally
Since its operation depends on a heat source supplied from the outside, when the supply of the external heat source stops, the circulating flow of the medium stops, and the function of the heat exchange device itself deteriorates.

The purpose of this invention is to eliminate the above-mentioned problems and provide a heat exchange device that can operate stably while taking advantage of the advantages of a bubble generator.

In short, this invention is a heat exchange device in which the heat source of the bubble generator for circulating the working medium is the heating fluid supplied to the evaporator.

Examples of this invention will be described below.

In FIG. 3, the passage 2 through which the heated fluid 19 passes is located below the passage 1 through which the heating fluid 18 passes, and as a result, the evaporation tube group 4 disposed within the heating passage 1 is located within the passage 2. It is located above the condensing tube group 8. 20 is heating fluid 1
8 bypass passage, which is attached to the heating fluid passage 1 so as to bypass the evaporation tube group 4. The bubble generator 11 is disposed within this bypass passage 20, and the bubble generator 11 and the lower header 3 of the evaporation tube group 4 are connected by a riser pipe line (hereinafter referred to as liquid lift pipe) 12. There is. 21 is a damper provided in the bypass passage.

Next, to explain the operating state of this device, the working medium that has radiated heat and condensed in the condenser tube group 8 passes through the lower header 9 of the condenser tube group 8, which is located lower than the lower header 3 of the evaporator tube group 4, and the liquid communication tube 10. The air bubble generator 11 is reached. Here, the bypass passage 20
The condensate 17 is heated by the heated fluid branch pipe 18 passing through it and generates bubbles. As a result, the condensate rises up the liquid lift pipe 12 due to the upward force of the bubbles,
The condensed liquid reaches the gas-liquid separator 13 and flows into the evaporation tube group 4, and the bubbles flow into the steam communication tube 6, merge with the steam 16, and are supplied to the condensation tube group.

In the above case, if the temperature of the heating fluid 18 is not very high, there is a risk of low-temperature corrosion occurring downstream of the evaporator tube group. 23 is a temperature controller provided to prevent this low-temperature corrosion, and the evaporator tube group 4
The opening degree of the damper 21 is adjusted by measuring the temperature of the fluid on the downstream side. In other words, if the temperature of the heating fluid 18 decreases, the opening degree of the damper 21 is reduced to reduce the amount of liquid pumped by the bubble generator 11, thereby reducing the amount of working medium circulated, and the fluid temperature on the downstream side of the evaporation tube group is reduced. Prevents the value from dropping below the set value. In this case, the increasing liquid flow rate is measured in the flow rate regulator 24,
This result may be input to the temperature controller 23 to perform cascade control.

FIG. 4 shows a structure in which the working medium circulation flow path shown in FIG. 3 is formed in double form, thereby increasing the heat transfer efficiency. Reference numerals 6' and 10' are a steam communication pipe and a liquid communication pipe, respectively, and 11' is a bubble generator.

In this device, the amount of heating fluid supplied to the steam generators 11, 11' is less than 10% of the total, and the heat amount of this heating fluid is used as latent heat by joining the steam 16 through bubbles in the liquid. Therefore, there is almost no thermal loss.

By implementing this idea, while taking advantage of the advantages of the bubble generator, even if the external heat source is located at a relative position, that is, the lower header of the evaporator tube group is located above the lower header of the condensing tube group, The heat exchange device can be operated stably.

[Brief explanation of drawings]

Figure 1 is a system diagram of a natural circulation heat exchanger, Figure 2
The figure is a system diagram of a conventional forced circulation heat exchanger.
The figure is a system diagram of a heat exchange device according to this invention, and FIG. 4 is a system diagram of a heat exchange device showing a modification of FIG. 3. 1... heating fluid passage, 4... evaporation tube group, 8...
Condensing tube group, 11... bubble generator, 18... heating fluid, 20... bypass passage, 21... damper.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A group of evaporation tubes with upper and lower headers is located in the heated fluid passage, a group of condensing tubes with upper and lower headers is located in the heated fluid passage, and the upper headers are connected to each other and the lower headers are connected to each other as pipes. In the connected heat exchange device, the lower header of the condensing tube group is located lower than the lower header of the evaporating tube group, and a bubble generator is provided in the rising pipe line to the evaporation part of the pipe line connecting the lower headers,
A forced circulation heat exchange device characterized in that this bubble generator is located in a heating fluid bypass line that bypasses the evaporation tube group. 2 Utility Model Registration In the forced circulation heat exchange device according to claim 1, a flow rate regulator is provided for the bypass passage, and the temperature of the fluid downstream of the evaporator tube group is adjusted by adjusting the bypass amount of the heating fluid. Something that is configured to be adjustable.