JPS6048401A - Waste-heat recovering steam generator - 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] [Field of Application of the Invention] The present invention relates to a JIP heat recovery steam generator, and in particular recovers the heat generated when condensing and liquefying distillate gas in a distillation column, etc. to produce low-pressure steam. The present invention relates to an exhaust heat recovery steam generator suitable for generating gas, pressurizing it with a compressor, and reusing it as a heat source for production equipment such as a distillation column.

[Sustainability of invention]

First, a conventional exhaust heat recovery steam generation device will be explained with reference to No. fil.

FIG. 1 is a schematic cross-sectional view and system diagram of a conventional exhaust heat recovery steam generator.

In the figure, numeral 10 denotes a distillation column, which is an example of a production apparatus a that uses saturated steam as a heat source and discharges distillate gas related to exhaust gas. Reference numeral 1 denotes an evaporator, which includes a group of heat transfer tubes 2 in a closed container and is configured to circulate water 3 around the group of heat transfer tubes. 4 and 5 are partition rooms. 7 is the compressor, 8 is the motor that drives the compressor, 6, 9.11 is the pipe that connects each device, and the arrow indicates the flow of gas, etc. The operation of the exhaust heat recovery steam generator having the following configuration will be explained.

The distillate gas discharged from the distillation q:xo flows into the partition chamber 4 from the inlet 4a of the evaporator 1 via the pipe 11, and in the process of flowing through the heat transfer tube group 2, it exchanges heat with the water 3 and loses heat. It is taken away, condensed and liquefied, and is drained from the partition chamber 5 through the discharge port 5a to the drain 12.
and is discharged.

The water 2 that takes heat from the distillate gas becomes hot water.
.

to generate low-pressure steam 13. Low pressure steam 13 is connected to pipe 6
The vapor is sucked into the compressor 7 through the pump, becomes saturated vapor that is pressurized to the required pressure, flows into the p1 distillation column 10 through the pipe 9, and is used as a heating source for the distillation column 10.

In this case, the distillate gas is a multicomponent exhaust gas containing water vapor and trichlene used as a bath agent, and the relationship between the condensation temperature and the heat of condensation of the distillate gas is shown in Figure 2. Please refer to and explain.

FIG. 2 is a diagram showing the relationship between the linear temperature of distillate gas and the amount of heat of condensation, with the horizontal axis representing the distillate gas condensation temperature T and the vertical axis representing the amount of condensation heat Q. ΔTld indicates temperature difference.

The distillate gas temperature when exhausted from the distillation column 10 is rJ,
It is indicated by No and is about 95-100C. The temperature at which the distillate gas exchanges heat with water and completely condenses is indicated by T2, and is approximately 80
~8! II'-1? be. The saturated steam temperature required by the distillation column 10 as a heating source is indicated by T, and is 104C. In this way, the required saturated steam temperature T and condensation temperature T2
Since the temperature difference ΔT is large, the power of the external pressure reservoir is also large, and the compressor requires two-stage compression. Therefore, there were problems in that a large initial investment was required and the energy saving effect was small.

[Purpose of the invention]

The present invention was made in order to solve the problems of the conventional technology, and is capable of efficiently recovering heat down to low temperatures when condensing exhaust gas. The purpose of this invention is to provide a waste heat recovery steam generator that is quick and has a large energy-saving effect.

[Summary of the invention]

The exhaust heat recovery steam generation device according to the present invention has a structure that includes an evaporator that introduces exhaust gas from a production device that uses saturated steam as a heat source into a group of heat transfer tubes, and generates steam by exchanging heat with water. In an exhaust heat recovery steam generation device that includes a compressor that sucks in and compresses saturated steam and discharges saturated steam, and piping that connects these, the evaporator is located at the second A first compressor that sucks and compresses the steam generated in the first evaporator, and a first compressor that sucks and compresses the steam generated in the first evaporator, and a second evaporator that combines the discharged steam of the first compressor and the second evaporator. It is equipped with a second compressor that sucks and compresses the steam generated in the container.

It should be noted that the present invention was made based on the following idea.

The distillate gas discharged from a distillation column is a multi-component vapor, and generally when the distillate gas is kept under constant pressure conditions, the relationship between cooling temperature and cooling heat amount is as shown in Figure 2. . In view of this characteristic, the heat recovery of the distillate gas is divided into two stages, the distillate gas is cooled from '1゛o to Ifl-, the amount of heat of Ql is recovered, and low-pressure steam is generated. Next, it is cooled to T2, and the heat amount of Q2 is recovered to generate low-pressure steam. Increase the pressure to T. In this way, when heat is recovered in two stages and the pressure is increased, as is clear from Fig. 2, the amount of heat recovered from the exhaust heat is increased by Δ゛1゛! Compared to the conventional method, which cools the total amount of heat to T2, recovers 11 minutes, and increases the pressure for 31 minutes, the power required to increase the pressure of Ql by ΔT2 is reduced. This saves a lot of power.

[Embodiments of the Invention] Hereinafter, an embodiment of the non-explosion ψ will be described with reference to FIG. 3 along with FIG. 2 above.

FIG. 3 is a schematic cross-sectional view and system diagram of a heat recovery steam generator according to an embodiment of the present invention. In the figure, the first
The same reference numerals as those in the figure indicate parts equivalent to those in the prior art, and arrows indicate the flow of gas, etc.

In the figure, reference numeral 20 denotes a first evaporator, which includes a heat exchanger tube group 22 in a closed container 21 and is configured to circulate water 3' around the heat exchanger tube group.

24.25 is a partition room. 27 is a first compressor, and 28 is a motor that drives the compressor.

26 transfers the low pressure steam 13' generated in the first evaporator to the first evaporator.
This is the piping that connects to the compressor.

30 is a second # generator, which has a heat exchanger tube IR-3 in a closed container 31.
2, that heat transfer tube! It is configured to circulate around Vc water 3 of 1t. 34.35 is service I)]
It's a proposal. 37 is the second compressor, 38 is the compressor 1
It is a driving motor. 36&, is a pipe for guiding the steam 13 generated in the second evaporator and the discharged steam compressed in the first compressor 27 to the second compressor 37. 40 is the second S
An evaporation pressure regulator in the generator, 41 is an evaporation pressure regulator 4
This is an evaporation pressure controller that opens and closes with a signal of 0, and is attached to the pipe 36. 9' is a pipe that guides the steam discharged from the first compressor 27 to the second evaporator 30; 9 is the steam discharged from the second compressor 37;
That is, it is a pipe that guides saturated steam to the distillation column IO.

The evaporator is a second evaporator 30. viewed from the distillate gas discharge side of the distillation column 10. The first evaporator 20 is arranged in this order, a first compressor 27 is arranged next to the first evaporator 20, and a second compressor 37 is arranged next to the second evaporator 30.

Next, the operation of the exhaust heat recovery steam generator configured as described above will be explained.

Distilled J! The distillate gas discharged from the pipe IJ flows into the partition chamber 34 from the suction port 34a of the second evaporator 30, and exchanges heat with the water 3 while flowing through the heat exchanger tube group 32. Since the pressure in the second evaporator 30 is controlled to be constant by the evaporation pressure regulator 40, the hot water 3 is maintained at the saturation temperature of the evaporation pressure, so the distillate gas is kept constant in the heat transfer tube 32. A portion of the distillate gas is condensed and liquefied. The latent heat generated during this condensation is recovered by the water 3, and the water 3 turns into hot water and generates steam 13.

Gas-liquid mixed gas 12' of distillate gas that did not condense in the heat exchanger tube group 32 of the evaporator 30 and liquefied drain;
The discharge port 35a is passed from the partition chamber 35 of the second evaporator to the first evaporator.
Introduced into the evaporator 20, the suction port 24a of the first evaporator 20
The heat exchanger passes through the partition chamber 24 to the heat exchanger tube group 22 .

On the other hand, the internal pressure of the first evaporator 20 is kept lower than the internal pressure of the second evaporator 30 by the action of the first compressor 270, so the temperature of the water 3' is also low and the distillate is further cooled. is,
Most of it is condensed and liquefied and becomes the drain 2 and is discharged from the partition chamber 25 to the outside of the apparatus through the discharge port 25a. At this time, the latent heat generated when the remaining distillate gas condenses and the sensible heat due to cooling of the condensed drain in the second steamer 30 are recovered into water 3', and water 3' becomes hot water. It evaporates and generates low pressure steam 13'. Low pressure steam 13'il: Piping 2
6 is sucked into the first compressor 27 and compressed, and the discharged steam from the first compressor 27 is transferred to the steam 1 in the second A generator 30 through the pipe 9'.
3. Introduced to the generation part. The low pressure steam 13 generated in the second evaporator 30 and the discharge steam of the first compressor 27 are connected to a pipe 36
The vapor is sucked into the second compressor 37 and compressed to become saturated vapor at a predetermined pressure. The high temperature and high pressure steam is
It flows into the distillation column 10 through one hole in the pipe 9 and is used as a heating source for the distillation column 10.

The action and effect of this acid are explained below with reference to FIG. 2.

Approximately 95 to 100 tl discharged from distillation column 10? The temperature of
Corpse T. The distillate gas is heated to a temperature of about 90C in the second evaporator 30.
The water 3 recovers the heat quantity of Ql condensed to L'fr and generates steam 13 (ill-). Next, the 1st.f generator 2
1 of the condensate by cooling at a temperature T21 of about 80-85r at 0.
Water 3' recovers the heat of Q2 and generates low-pressure steam 13'. The amount of heat of Q2 is outputted from T2 by the first compressor 27 as TI-f.

(If heat recovery is divided into two stages as shown in Figure 2 and the pressure is increased, the pressure will only increase by the amount of Ql, ΔIII, out of the amount of heat recovered from the exhaust heat, as shown in Figure 2. Compared to the method of cooling and recovering the amount of heat to T2 and increasing the pressure by 31 minutes, the power of the compressor is less than the power required to increase the pressure of Ql by 412 minutes, and a large amount of power can be saved. Compared to the conventional method in which the steam generated by exhaust heat 1i'1 is generated from low pressure, the total amount of steam is reduced by 6~
70% of the pressure is raised from the L factor ■] pressure at a specified pressure point, and the remaining
Since ~30% of the pressure is increased from low pressure, the power consumption of the compressor can be reduced by 30~40%.

Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a schematic sectional view and system diagram of an exhaust heat recovery steam generation device according to another embodiment of the present invention.

In the figure, the parts with the same numbers as those in FIG. 3 are the same parts as in the previous example, so their explanation will be omitted.

The basic configuration of this example is the same as the implementation shown in FIG.
is connected to the lower part 31a of the heat exchanger tube group 32 of the second evaporator 30.

With this configuration, the discharged steam of the first compressor 27 is blown into the lower part of the heat exchanger tube group 32 of the second evaporator 30, so the water 3 around the heat exchanger tube group 32 is stirred, and the evaporation of the water 3 is promoted. Ru. Therefore, the difference between the IAA degree of the distillate gas to be heat exchanged is reduced, and since the distillate gas is evaporated at a higher temperature, the power consumption of the pressurizer can be further reduced.

Note that in the above embodiment, saturated steam was used as the heat source.
Although the use of a distillation column as a production device for discharging JP gas has been explained, the present invention is not limited to a distillation column, but is applicable to production devices that can be expected to have effects such as circulation. be.

Furthermore, in the above embodiment, the exhaust heat of the distillate gas discharged from the distillation column is recovered, the pressure of the generated steam is increased, and the steam is returned to the distillation column for reuse. j'J t, the circulation is not limited to production equipment → exhaust heat recovery steam generator → production equipment u, but the steam generated from the exhaust heat recovery steam generator and pressurized can be diverted to other production equipment. It is also possible.

[Effect of Uchiaki]

As described above, according to the present invention, heat can be efficiently recovered down to low temperatures when exhaust gas is condensed, and waste heat recovery can quickly recover the initial investment and has a large energy-saving effect. A steam generator can be provided.

[Brief explanation of drawings]

Figure 1 is a schematic sectional view and system diagram of a conventional waste heat recovery steam generator; Figure 2 is a diagram showing the relationship between the condensation temperature of distillate gas and the condensing heat lid; Figure 3 is A schematic cross-sectional view and a system diagram of an exhaust heat recovery steam generator according to an embodiment of the present invention, FIG. 4 is a schematic cross-sectional view and a system diagram of an exhaust heat recovery steam generator according to another embodiment of the present invention. It is a diagram. 3.3'... Water (hot water), 9.9', 9'', 11°26.36... Piping, 10... Distillation column 13.13
'...steam, 20...first evaporator, 30...second
Evaporator, 22. 32... Heat exchanger tube group, 27... First compressor, 37 No. 1 Figure Z Figure 4 Figure j' z0

Claims (1)

[Claims] 1. An evaporator that introduces exhaust gas from a production device that uses saturated steam as a heat source into a group of heat transfer tubes and exchanges heat with water to generate steam, and an evaporator that sucks and compresses the steam. Exhaust heat consisting of a compressor that discharges saturated steam and piping that connects these [U] In the steam generation device, the evaporator is divided into a second evaporator, a first evaporator, and a second evaporator when viewed from the exhaust gas discharge side of the production device. a first compressor which is arranged separately in the order of the first evaporator and sucks and compresses the vapor generated in the first evaporator; a first compressor which sucks the discharged vapor of the first compressor and the vapor generated in the second evaporator; An exhaust heat recovery steam generation device characterized by being equipped with a second compressor for compression. 2. The exhaust heat recovery steam generation according to claim 1, which is provided with piping connecting the discharge side of the first compressor and the lower part of the heat transfer tube group of the second evaporator. Device.