JPH0710226Y2 - Air liquefaction separation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an air liquefaction / separation device, and more particularly, to a washing and cooling tower which is means for cooling raw material air that has been heated by being compressed by a raw material air compressor, The present invention relates to a cooling means for a turbine fluid that has been heated by being compressed by a booster in an air liquefaction separation device provided with a booster for boosting a part of raw material air as a turbine fluid of an expansion turbine.

[Prior Art] FIG. 3 shows an example of a main part of a conventional air liquefaction separation apparatus. In this air liquefaction separation apparatus 1, a raw material air compressor 2 for compressing a raw material air A and a compressed air are used. A water washing cooling tower 3 for cooling and washing the high temperature raw material air A, and a set of adsorbers 4 and 4 for purifying the raw material air A by removing water and carbon dioxide gas,
Product gas Gp and exhaust gas after rectification separation of raw material air A after purification
A main heat exchanger 5 for heat exchange with Gw for cooling is provided, and in addition, in order to obtain the refrigeration necessary for the rectification separation operation, a part of the raw material air A after purification is branched as a turbine fluid. A booster 6 and an expansion turbine 7 are provided for boosting pressure and then expanding to generate cold. The booster 6 is provided with a precooler 8 and a heat exchanger 9 that cool the turbine fluid T that has been compressed by the booster 6 and has risen in temperature. The turbine fluid T that has been boosted by the booster 6 to raise its temperature is
After being cooled in the precooler 8 and further cooled in the heat exchanger 9 by exchanging heat with the turbine fluid T before pressurization, it is cooled to a predetermined temperature in the main heat exchanger 5 and introduced into the expansion turbine 7. It expands and produces cold.

The raw material air A is introduced into a rectification column (not shown) after being compressed, purified and cooled through these devices, and rectified by a known rectification operation to produce a product gas Gp such as nitrogen or oxygen and an exhaust gas.
Separated into Gw. The product gas Gp and the exhaust gas Gw are discharged while the raw air A is cooled by the main heat exchanger 5 and the temperature of itself is recovered.

The washing and cooling tower 3 cools and cleans the raw material air A with the cooling water W, and the washing and cooling tower 3 includes:
The cooling water tower 10 for cooling the cooling water W by utilizing a part of the exhaust gas Gw discharged after the rectification separation and the washing tower 3 for washing the cooling water W
A chilled water pump 11 for supplying water is supplied to the upper part of the washing and cooling tower 3.

[Problems to be solved by the device]

However, in the above-mentioned one, since the turbine fluid T that has been pressurized and raised by the booster 6 is heat-exchanged with the turbine fluid T before being boosted, that is, a part of the raw material air A, the main heat exchanger 5 has A temperature difference occurs in the warm end device 5a. For example, if the temperature of the raw material air A discharged from the adsorber 4 is 18 ° C., the turbine fluid T before the pressure increase of 18 ° C. is performed in the heat exchanger 9.
And the turbine fluid T, which has been cooled by the precooler 8 and has reached about 35 ° C. after pressure increase, performs heat exchange. Therefore, the temperature of the turbine fluid T after pressure increase, which is cooled by heat exchange and then derived, is about Cooling down to 20 ° C is the limit. Therefore, the raw air A of 18 ° C. and the turbine fluid T of 20 ° C. are introduced into the warm end 5a of the main heat exchanger 5, which is not preferable for the main heat exchanger 5.

Further, since the turbine fluid T passes through the narrow flow path of the heat exchanger 9 before being introduced into the booster 6, a pressure loss occurs, and heat is exchanged with the turbine fluid T that has been heated by pressurization to raise the temperature. Since the booster 6 is inhaled in this state,
Compression efficiency is reduced.

Therefore, the present invention eliminates the temperature difference between the raw material air A introduced into the main heat exchanger 5 and the turbine fluid T, and eliminates the pressure loss and temperature rise of the turbine fluid T before the introduction of the booster 6, thereby increasing the booster. It is an object of the present invention to provide an air liquefaction separation device capable of improving the efficiency of No. 6 above.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a washing and cooling tower that cools the raw material air that is compressed and heated by a raw material air compressor, and a part of the raw material air that is branched after being purified by an adsorber as a turbine fluid. Air having a booster for boosting pressure, a main heat exchanger for cooling the feed air and the turbine fluid, and an expansion turnbin for expanding the turbine fluid cooled to a predetermined temperature in the main heat exchanger to generate cold. In the liquefaction separation device, between the booster and the main heat exchanger, heat exchange is performed between the turbine fluid that has been pressurized and raised by the booster and a part of the low-temperature cooling water that is introduced into the washing cooling tower. The feature is that a heat exchanger is provided.

Further, the present invention provides a precooler between the booster and the heat exchanger, the precooler precooling the turbine fluid that has been pressurized by the booster and has risen in temperature. It is provided with a flow path of room temperature cooling water such as industrial water from the middle part to the warm end of the exchanger, and a flow path of the low temperature cooling water from the cold end of the heat exchanger to the middle part. It has a feature.

[Action]

As described above, a part of the low-temperature cooling water that cools the raw material air that has been compressed by the raw material air compressor and has reached a high temperature, by cooling the turbine fluid that has been heated up by the booster,
It is possible to cool the adsorber to the same temperature as the discharged raw material air, and to make the raw material gas and the turbine fluid introduced into the main heat exchanger have the same temperature. Furthermore, since the turbine fluid branched from the raw air can be directly introduced to the booster,
Since there is no pressure loss and no temperature rise, the compression efficiency of the booster can be improved.

Further, by disposing the precooler between the booster and the heat exchanger, the load on the heat exchanger can be reduced and the required amount of low-temperature cooling water can be reduced. Furthermore, by providing the normal temperature cooling water flow path and the low temperature cooling water flow path in the heat exchanger, it is possible to cool the heated turbine fluid to the appropriate temperature with the normal temperature cooling water and then to cool it with the low temperature cooling water. The turbine fluid can be cooled with one heat exchanger and a small amount of low-temperature cooling water.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. In the following description, the same elements as those of the conventional example shown in FIG. 3 are designated by the same reference numerals and detailed description thereof will be omitted.

First, FIG. 1 shows an embodiment of an air liquefaction separation apparatus of the present invention. This air liquefaction separation apparatus 20 includes a precooler 8 and a heat exchanger between a booster 6 and a main heat exchanger 5. 21 is provided.

In the heat exchanger 21, a pipe line for introducing a part of the low temperature cooling water Wc introduced from the cold water tower 10 into the water washing cooling tower 3 into the heat exchanger 21.
22 and a pipe line 23 for returning the low-temperature cooling water Wc which has been heated by exchanging heat with the turbine fluid T in the heat exchanger 21 to the cold water tower 10 and which are provided with the cold water pump 11 by the pipe lines 22 and 23. A part of the low-temperature cooling water Wc discharged from is introduced and circulated.

The temperature-raised cooling water led to the pipeline 23 may be directly returned to the cold water tower 10 and circulated, or may be once joined with industrial water or the like, and a part of the industrial water is introduced into the cold water tower 10. You may do it. In addition, the precooler 8 has a room temperature cooling water Wn such as industrial water.
Has been introduced.

The raw material air A compressed to about 5.5 kg / cm ² G by the raw material air compressor ² is cooled to about 12 ° C. by the low temperature cooling water Wc in the water washing cooling tower 3 and then introduced into one of the adsorbers 4. It is refined and heated to about 18 ° C and then discharged. Most of the raw material air A discharged from the adsorber 4 is introduced into the main heat exchanger 5 as it is, for example, 75%, and heat exchange with the product gas Gp and exhaust gas Gw after rectification and separation is performed in the main heat exchanger 5. It is cooled to near the liquefaction point and introduced into the rectification column.

A part of the raw material air A, for example 25%, is branched to the pipe line 24 as the turbine fluid T, compressed by the booster 6, and is about 11 kg / cm ² G.
And the temperature rises to about 85 ° C. The heated turbine fluid T is introduced into the precooler 8 and cooled to about 30 ° C. room temperature cooling water.
It is cooled by Wn to about 35 ℃. Next, this turbine fluid T is introduced into the heat exchanger 21 and exchanges heat with the low temperature cooling water Wc of about 9 ° C. used in the water washing cooling tower 3 and has the same temperature as that of the raw material air A discharged from the adsorber 4. It is cooled to ℃.

The turbine fluid T that has reached the same temperature as the raw material air A is introduced into the main heat exchanger 5 together with the raw material air A. Main heat exchanger 5
The turbine fluid T, which has been further cooled to a predetermined temperature and led out from the intermediate portion of the main heat exchanger 5, expands in the expansion turbine 7 to generate cold, and serves as a drive source for the booster 6.

Here, the low temperature cooling water Wc used for cooling the raw material air A in the water washing cooling tower 3 and for cooling a part of the turbine fluid T can be obtained as follows.

Exhaust gas Gw that exchanges heat with raw material air A and turbine fluid T in the main heat exchanger 5 and recovers its temperature to 16 ° C. and is discharged is partly introduced into the cold water tower 10 attached to the washing and cooling tower 3. To be done. Since this exhaust gas Gw is a dry gas that does not contain any moisture, water at room temperature introduced into the cold water tower 10, for example, industrial water, is used after the heat exchange with the turbine fluid T is completed in the heat exchanger 21 for about 30 minutes. It is possible to cool the low-temperature cooling water Wc heated to ℃, the cooling water discharged from the washing and cooling tower 3 and circulated, to about 9 ° C. The low-temperature cooling water Wc thus obtained in the cold water tower 10 is supplied to the washing and cooling tower 3 and the heat exchanger 21 by the cold water pump 11 and circulates.

In this way, the turbine fluid T that has been compressed and heated by the booster 6 is introduced into the main heat exchanger 5 by heat exchange with the low-temperature cooling water Wc that cools the raw material air A to cool it. The temperature can be the same as that of the raw material air A to be used. Further, since the heat exchanger is not provided on the suction side of the booster 6, no pressure loss occurs, and since the compression is performed at a low temperature while the adsorber 4 is led out, the compression efficiency can be improved.

Next, FIG. 2 shows another embodiment of the present invention. In this air liquefaction / separation device 30, a passage 31 for the room temperature cooling water Wn is provided between the booster 6 and the main heat exchanger 5. A heat exchanger 33 having a flow path 32 for the low temperature cooling water Wc is arranged.

The flow path 31 of the room temperature cooling water Wn extends from the middle part of the heat exchanger 33 to the warm end 33a, and the room temperature industrial water or the like is introduced into the flow path 31 of the room temperature cooling water Wn to increase the pressure. The turbine fluid T, which has been pressurized by the machine 6 and heated to about 85 ° C., is cooled to about 35 ° C.

Further, the flow path 32 of the low-temperature cooling water Wc is the cold end 33b of the heat exchanger 33.
In the same manner as in the above embodiment, a part of the low temperature cooling water Wc for cooling the raw material air A in the washing and cooling 3 etc. is introduced, and the room temperature cooling water Wn of the flow path 31 raises the temperature to about 35 ° C. The raw material air A that draws out the cooled turbine fluid T from the adsorber 4
It is cooled to the same 18 ℃.

The room-temperature cooling water Wn is supplied from, for example, a cooling tower for circulation, and the room-temperature cooling water Wn is introduced into the middle portion of the water-washing cooling tower 3 in order to improve the cooling efficiency of the water-washing cooling tower 3. A part of the cooling water Wn can be used.

In this way, by disposing the heat exchanger 33 having the flow paths 31 and 32 for the cooling water Wn and Wc at normal temperature and low temperature, respectively,
The apparatus cost can be reduced as compared with the case where the precooler 8 and the heat exchanger 21 are respectively arranged as in the above embodiment.

Although it is possible to cool the turbine fluid T to the same temperature as the raw material air A without using the room temperature cooling water Wn, for example, the temperature of the compressed turbine fluid T is 85 ° C. and the temperature of the low temperature cooling water Wc. Is 9 ° C., and 20 t / h of low temperature cooling water Wc is required to cool the turbine fluid T from 85 ° C. to 18 ° C. only with the low temperature cooling water Wc, the precooler 8 Or by providing the flow path 31 for the room temperature cooling water Wn,
If the turbine fluid T is cooled to 35 ° C. by the room temperature cooling water Wn of about 30 ° C., the amount of the low temperature cooling water Wc required to cool the 35 ° C. turbine fluid T to 18 ° C. is about 7.5 t / h. Can be With this, about 20 tons of water can be
The energy for cooling to ℃ can be reduced. In particular, the rectification separation efficiency is high, the amount of product gas is large, and the amount of exhaust gas is small In an air liquefaction separation device, an auxiliary equipment such as a refrigerator may be provided to obtain the low-temperature cooling water Wc. It is desirable to reduce the amount of the low-temperature cooling water Wc used by precooling with the room-temperature cooling water Wn.

Further, other components such as a rectification column portion other than those shown in the figure, and other various devices used in a normal air liquefaction separation device can be used in the same manner as in the past, and may be appropriately selected depending on the type, properties, quantity, etc. of the product to be collected. It can be configured in various ways. It goes without saying that the booster 6 described in this embodiment can be used as a braking blower for the expansion turbine 7 as shown in FIG.

[Effect of device]

As described above, according to the present invention, the heat exchanger for exchanging heat between the turbine fluid and the low-temperature cooling water is provided between the booster and the main heat exchanger. It is possible to cool to the same temperature as above, and it is possible to bring the raw material gas and the turbine fluid introduced into the main heat exchanger to the same temperature. Therefore, the temperature distribution in the main heat exchanger can be made uniform, and the heat exchange efficiency can be improved. Furthermore, since the turbine fluid branched from the raw material air can be directly introduced into the booster, there is no pressure loss and there is no temperature rise, so the compression efficiency of the booster is improved and the pressure can be raised to a higher pressure than in the conventional case. The expansion rate in the expansion turbine can be increased to increase the amount of cold produced.

Further, by disposing a pre-cooler between the booster and the heat exchanger, the load on the heat exchanger can be reduced and the required amount of low-temperature cooling water can be reduced. It can be reduced. Further, the heat exchanger is provided with a room temperature cooling water channel and a low temperature cooling water channel, and is configured to cool the heated turbine fluid to a proper temperature with the room temperature cooling water and then to cool it with the low temperature cooling water. As a result, with one heat exchanger,
In addition, the turbine fluid can be cooled with a small amount of low-temperature cooling water, and the cost of the apparatus can be reduced and the piping work in the manufacturing process can be reduced, which can reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a system diagram of a main part of an air liquefaction separation apparatus showing an embodiment of the present invention, FIG. 2 is a system diagram of a main part showing another embodiment of the present invention, and FIG. 3 is a main part showing a conventional example. FIG. 2 ... Raw material air compressor, 3 ... Washing cooling tower 4 ... Adsorber, 5 ... Main heat exchanger, 6 ... Booster, 7 ... Expansion turbine, 8 ... Precooler, 10 ... Cold water tower 20,30 …… Air liquefaction separation device 21 …… Heat exchanger, 22, 23, 24 …… Pipe line 31 …… Room temperature cooling water flow path, 32 …… Low temperature cooling water flow path 33 …… Heat exchanger , A ... Raw air, Gw ... Exhaust gas, Wc ...
… Low temperature cooling water, Wn …… Room temperature cooling water

Claims (3)

[Scope of utility model registration request] 1. A water washing cooling tower for cooling the raw material air compressed by the raw material air compressor and heated, and a booster for boosting a part of the raw material air which has been purified by an adsorber and branched off as a turbine fluid. In the air liquefaction separation device including a main heat exchanger that cools the raw material air and the turbine fluid, and an expansion turbine that expands the turbine fluid cooled to a predetermined temperature by the main heat exchanger to generate cold A heat exchanger for exchanging heat between the turbine fluid that has been boosted and heated by the booster and a part of the low-temperature cooling water to be introduced into the flush cooling tower is provided between the machine and the main heat exchanger. An air liquefaction separator. 2. An air liquefaction separation system according to claim 1, further comprising a precooler provided between the booster and the heat exchanger for precooling the turbine fluid that has been pressurized and raised in temperature by the booster. apparatus. 3. The heat exchanger comprises: a flow path for normal temperature cooling water such as industrial water from an intermediate portion to a warm end of the heat exchanger; and a flow passage from a cold end to an intermediate portion of the heat exchanger. The air liquefaction separation apparatus according to claim 1, further comprising: a low temperature cooling water channel.