JP4310111B2 - Compressed air dehumidifying device and dehumidifying reheat device - Google Patents

Description

となる（ただし水の蒸発潜熱６００kcal/kg）。したがって
必要冷却量（ｑ₁）＝（１）＋（２）＝３３，４００kcal/h
となるから、水の熱容量１ｍ³：１，０００ｋｃａｌ／℃より、
必要井水量（Ｖ₁）＝３３，４００÷１，０００÷１０＝３．３４ｍ³／ｈ
となる。
【００３６】
冷却水量（Ｖ₂）＝インタークーラ冷却水量Ｖ₂’＋アフタークーラ冷却水量Ｖ”である。また
インタークーラ冷却水量（Ｖ₂’）＝インタークーラ冷却量ｑ₂’÷６℃（利用温度差）である。インタークーラの入り口空気温度１５５℃、出口空気温度４０℃とすると、
インタークーラ冷却量（ｑ₂’）＝６，０００×１．２×０．２４×（１５５−４０）≒１９９，０００kcal/h
となる。したがって熱ロスを１０％見込んで
インタークーラ冷却水量（Ｖ₂’）＝１９９，０００÷１，０００÷６×１．１≒３６．５ｍ³／ｈ
となり、オイルクーラなどの冷却分約２０％を見込むと、
Ｖ₂’＝３６．５×１．２＝４４ｍ³／ｈ
となる。
【００３７】
他方、アフタークーラ冷却水量（Ｖ₂”）＝アフタークーラ冷却量ｑ₃’÷５℃（利用温度差）である。
アフタークーラ冷却量（ｑ₃）＝６，０００×１．２×０．２４×（１７５−３７）≒２３９，０００kcal/h
であるから、熱ロス１０％見込んで、
アフタークーラ冷却水量（Ｖ₂”）＝２３９，０００÷１，０００÷５×１．１≒５３ｍ³／ｈ
となる。したがって
冷却水量（Ｖ₂）＝Ｖ₂’＋Ｖ₂”＝４４＋５３＝９７ｍ³／ｈ
である。
【００３８】
通常、インタークーラ、アフタークーラは、冷却水利用温度差を５〜１０℃の範囲で設計されており、上記利用温度差でも問題はない。
【００３９】
インタークーラおよびアフタークーラで必要な冷却水の流量Ｖ₂ に対する井水の流量Ｖ1の割合はＶ1／Ｖ2＝３．３４／９７≒０．０３４＝３．４％である。このように井水の必要量は冷却水流量の約３．４％であり、通常必要なクーリングタワーの補給量とほぼ同程度である。すなわち無駄に使用していた補給水の冷熱を有効に利用するだけで足りることになる。
【図面の簡単な説明】
【図１】 本発明の除湿再熱装置を備えた圧縮空気供給システムの全体を示す配管系統図である。
【図２】 図１のシステムの除湿再熱装置の作用を示すグラフである。
【図３】 図１のシステムの再熱用熱交換器の作用を示すグラフである。
【図４】 本発明の除湿装置を備えた圧縮空気供給システムの他の実施形態を示す配管系統図である。
【図５】 従来の圧縮空気供給システムの一例を示す配管系統図である。
【図６】 非特許文献１の圧縮空気脱湿脱油装置の概略図である。
【符号の説明】
１０ 圧縮空気供給システム
１１ コンプレッサ
１２ 除湿再熱装置
１４ １段目の圧縮部
１５ ２段目の圧縮部
１６ 管路
１７ インタークーラ
Ｍ モータ
ＣＴ クーリングタワー
１８ 冷却水供給管路
１９ 戻り管路
２０、２０ａ、２０ｂ、２０ｃ、２０ｄ 供給エア管路
２１ 再熱用熱交換器
２２ アフタークーラ
２３ 補給水管路
２３ａ、２３ｂ 接続管路
２４ 井水利用の熱交換器
２５ バイパス管路
Ｖ1 流量調整バルブ
Ｔ 温度センサ
ＴＩＣ1 温度制御装置
Ｖ2 流量調整バルブ
ＴＩＣ１、ＴＩＣ2 温度制御装置
２７ バイパス管路
３０ 圧縮空気供給システム
ＣＴ１ 第１クーリングタワー
ＣＴ２ 第２クーリングタワー
３１ 冷却除湿塔
３２ 管路
３３ デミスタ
３４ フィルタ
１０１ コンプレッサ
１０２ 冷凍式ドライヤ
１０３ １段目の圧縮部
１０４ ２段目の圧縮部
１０５ インタークーラ
ＣＴ１、ＣＴ２ クーリングタワー
１０７ 供給エア管路
１０８ アフタークーラ
１０９ 補給水管路
１１０ ポンプ
１１２ 蒸発器
１１３ 凝縮器
１１４ レヒータ
１１６ 熱交換器
１１７ 蒸発弁
１２０ 圧縮空気脱湿脱油装置
１２１ クーリングタワー
１２２ 冷却水循環ポンプ
１２３ 冷却除湿塔
１２４ 空気入り口
１２５ 空気出口
１２６ ドレン[0001]
BACKGROUND OF THE INVENTION
  The present invention is compressed airRemovalIt relates to a wet reheat device. More specifically, it is used in a compressed air supply system that supplies compressed air to a compressed air pipe in a factory.That removalIt relates to a wet reheat device.
[0002]
[Prior art]
[Non-Patent Document 1]
Catalog of Sumida Facility Industry Co., Ltd. cooling tower type compressed air dehumidification and deoiling equipment (trade name Hygromaster)
[Patent Document 1]
Japanese Patent Laid-Open No. 48-91668
[0003]
The conventional compressed air supply to the compressed air piping in the factory is, for example, as shown in FIG. 5, a two-stage compression compressor 101 and a refrigeration for cooling and dehumidifying the compressed air supplied from the compressor. This is performed by a compressed air supply system 100 composed of a dryer 102 of the type. An intercooler 105 is interposed in the middle of the pipeline from the first stage compression unit 103 to the second stage compression unit 104 of the compressor 101. The intercooler 105 is cooled by the cooling water supplied from the first cooling tower CT1. Further, a supply air pipe 107 connected to the outlet side of the second stage compression unit 104 is connected to an aftercooler 108 cooled by cooling water supplied from the first cooling tower CT1, and further, the above-described dryer 102 is connected. Has been reached. The first cooling tower CT1 is connected to a makeup water pipe 109 for supplying well water or the like as makeup water. Reference numeral 110 denotes a cooling water pump.
[0004]
The refrigeration dryer 102 includes an evaporator 112 interposed in a supply air pipe 107, a compressor (compressor) 113 that compresses refrigerant vapor returning from the evaporator 112, and a supply air pipe 107. A reheater 114 which is provided downstream of the evaporator 112 and heats the compressed air to about 30 ° C. by exchanging heat between the high-temperature and high-pressure refrigerant vapor coming out of the compressor 113 and the air in the supply air pipe 107; Have Further, the dryer 102 includes a second cooling tower CT2 and a heat exchanger (condenser) 116 for exchanging heat between the cooling water from the cooling tower and the refrigerant coming out of the reheater 114. The refrigerant coming out of the heat exchanger 116 is sent to the evaporator 112 through the evaporation valve 117, and piping is performed so that the compressed air is cooled and dehumidified by the heat of vaporization. The cooling towers CT1 and CT2 do not need to be divided into two units, and cooling water may be supplied from one cooling tower to the compressor 101 and the refrigeration dryer 102.
[0005]
On the other hand, Non-Patent Document 1 discloses a cooling tower type compressed air dehumidifying / deoiling device 120 as shown in FIG. In this apparatus, the cooling water sent out from the cooling tower 121 by the cooling water circulation pump 122 is heat-exchanged with the compressed air in the cooling dehumidification tower 123 and returned to the cooling tower 121 again. The compressed air flowing in from the air inlet 124 is cooled and dehumidified in the cooling dehumidification tower 123 and exits from the upper air outlet 125. Reference numeral 126 denotes a drain for discharging water removed from the compressed air. This has a simpler configuration than that of FIG. 5 in that the compressed air is dehumidified with cooling water supplied from the cooling tower 121 without using a refrigerator. In addition, it can be considered that a cooling and dehumidifying tower 123 having a cooling and dehumidifying action is employed instead of the aftercooler 108 in the apparatus of FIG.
[0006]
Patent Document 1 discloses a compressed air dehumidifying dehumidification method and apparatus for spraying a cooling liquid on the cooling and dehumidifying tower 123 of Non-Patent Document 1 and thereby dissolving and capturing oil in the compressed air. Yes. The dehumidifying effect of this is considered to be the same as in Non-Patent Document 1.
[0007]
[Problems to be solved by the invention]
The general compressed air supply system 100 in FIG. 5 selects the refrigeration dryer 102 under the most disadvantageous conditions in winter and performs dehumidification. Therefore, the supplied compressed air is sufficiently dehumidified and has high quality. Compressed air can be supplied. However, since refrigeration cooling is used, there is a problem in that power consumption is large and unnecessary volume reduction is performed due to excessive dehumidification. Moreover, although well water etc. are utilized as supplementary water for the maintenance of the quality of cooling water, the cold heat is not fully utilized.
[0008]
On the other hand, the apparatus 120 of Non-Patent Document 1 does not require a refrigerator, but requires a large cooling and dehumidifying tower 123 to obtain a sufficient dehumidifying action. Also in this device 120, the cooling water supplied to the cooling tower 121 is not effectively used and is wasted.
[0009]
  The present invention can be suitably applied to the requirement of dehumidification of compressed air to the extent that condensation does not occur in the piping, that is, does not require an excessively low dew point, has low power consumption, and wasteful volume due to excessive dehumidification The technical challenge is to provide a dehumidifying and reheating device for compressed air with little reduction.
[0010]
[Means for Solving the Problems]
  Dehumidification of compressed air of the present inventionReheatThe device (claim 1) comprises:Used for a two-stage compressor that supplies compressed air.With cooling water supplied by cooling towerWith compressed airAfter-cooler for heat exchangeRemovalWetReheatApparatus comprising the compressor2nd stage compression partSupply air pipe for passing compressed air supplied from the cooling tower and the cooling towerwellA supply water line for replenishing water and an intermediate part of the supply air lineHeat exchange between the compressed air in the supply air line and the cooling water from the cooling towerAfter-coolerAnd its aftercoolerProvided on the downstream side ofAfter after coolerSupply air pipelineCompressed air insideAnd makeup water pipelineInside makeup waterA heat exchanger that exchanges heat withThe heat exchanger for reheating which exchanges heat between the supply air coming out of the heat exchanger and the high temperature air coming out from the second stage of the compressorWithAnd,The supply air line is adapted to convert the high-temperature compressed air that has come out of the second-stage compression section of the compressor into the high-temperature side of the reheat heat exchanger, the aftercooler, the heat exchanger, and the reheat heat exchanger. The heat exchanger is connected to a replenishing water line for replenishing well water to the cooling tower and an aftercooler outlet side of the supply air line, and comes out of the aftercooler. Heat is exchanged between the compressed air and the makeup water before being replenished to the cooling tower, and the heat exchanger for reheating is supplied from the heat exchanger and the outlet side of the second stage compression section Heat exchange with hot airIt is characterized by doing.
[0011]
  like thisDehumidification reheat deviceInIsA bypass conduit is connected between the air supply conduit before entering the low temperature side of the heat exchanger for reheating and the air supply conduit after exiting, and a flow rate adjusting valve is provided in the middle of the bypass conduit. The actuator of the flow rate adjusting valve is configured such that the temperature of the compressed air in the air supply line is a predetermined temperature based on a signal from a temperature sensor that detects the temperature of the air supply line or a use point where the supply air is used. It is preferable that the opening degree is adjusted so as to satisfy (Claim 2).
[0012]
[Operation and effect of the invention]
  The dehumidifier of the present invention (Claim 1) is a well that is supplied to a cooling tower.WaterSince the heat exchanger that exchanges heat between the makeup water and the compressed air is employed, the cold energy of the makeup water can be used effectively. Note that the makeup water sent to the cooling tower is not affected by any temperature rise because it only compensates for the deficiency due to natural evaporation of water used in the cooling tower and maintains the water quality. . In the apparatus of the present invention, power consumption can be reduced by effectively utilizing the unused energy and not performing refrigeration cooling. Furthermore, since the apparatus of the present invention does not depend on freezing and cooling as described above, moderate dehumidification is performed, and volume reduction due to excessive dehumidification can be reduced.
[0013]
  Also, once the hot compressed air from the compressor, By the aftercooler in the dehumidifying reheaterCooling water sent from the cooling towerBy exchanging heat withCool to some extent, thenContinueA well with a lower temperature fieldWaterSince it is supercooled with make-up water, the cooling and dehumidifying effect is high.
[0014]
  Dehumidifying and reheating device of the present inventionsoIsTheFurther, the compressed air coming out of the heat exchanger is reheated by the high-temperature air upstream of the aftercooler. Therefore, the compressed air that is finally delivered expands in volume, and the energy increases. Thereby, the heat energy exchanged by the aftercooler and radiated from the cooling tower can be used effectively, and the driving power of the compressor can be reduced. Further, the temperature rise makes it difficult for condensation in the pipe to occur.
  In such a dehumidifying and reheating device, a bypass pipe is connected between the air supply pipe before entering the low temperature side of the reheat heat exchanger and the air supply pipe after exiting, and the bypass pipe A flow rate adjusting valve is provided in the middle of the path, and the actuator of the flow rate adjusting valve is configured to receive the air supply line by a signal from a temperature sensor that detects a temperature of the air supply line or a use point where the supply air is used. When the opening degree is adjusted so that the temperature of the compressed air inside becomes a predetermined temperature (Claim 2), the temperature of the finally supplied compressed air is stabilized.
  That is, when the temperature of the compressed air becomes higher than a predetermined temperature, the opening of the flow rate adjusting valve is increased to increase the flow rate of the bypass passage, and the flow rate of air passing through the reheat heat exchanger is decreased. In that case, the temperature rise by the heat exchanger for reheating is suppressed as the whole supply air. Conversely, when the temperature is lower than the predetermined temperature, the temperature is increased as a whole by increasing the flow rate of the air passed through the reheat heat exchanger. Thereby, the temperature of the supplied compressed air is adjusted to a predetermined temperature.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the dehumidifying and reheating device of the present invention will be described with reference to the drawings. FIG. 1 is a piping system diagram showing the entire compressed air supply system provided with the dehumidifying and reheating device of the present invention, FIGS. 2 and 3 are graphs showing the operation of the dehumidifying and reheating device of the system of FIG. 1, and FIG. It is a piping system diagram which shows other embodiment of the compressed air supply system provided with the dehumidification reheat apparatus of this invention.
[0016]
A compressed air supply system 10 in FIG. 1 includes a compressor 11 and a dehumidifying and reheating device 12 for cooling and dehumidifying the compressed air supplied from the compressor and reheating the compressed air. The compressor 11 is substantially the same as that used in the compressed air supply system 100 of FIG. 5 except that the aftercooler 22 is disposed not on the compressor 11 but on the dehumidifying / reheating device 12 side. Yes. In this system 10, only one cooling tower CT is provided, but two or more cooling towers CT may be provided as in the case of FIGS.
[0017]
In this embodiment, the compressor 11 employs a two-stage compression type equipped with an intercooler 17 in the middle of a pipeline 16 from the first-stage compression section 14 to the second-stage compression section 15. Yes. The type of the compressor constituting each of the compression units 14 and 15 may be any of a reciprocating type, a turbo type, and a screw type, but usually a screw type is often used. The first stage compression unit 14 and the second stage compression unit 15 are driven by a common motor M. The intercooler 17 is connected to the cooling tower CT by a cooling water supply pipe 18 and a return pipe 19 so as to be cooled by exchanging heat with the cooling water supplied from the cooling tower CT. The temperature of the cooling water is, for example, about 10 ° C. to 32 ° C., and is set to, for example, about 32 ° C. in the design in consideration of the summer season. Well water is supplied to the cooling tower CT as makeup water through the makeup water pipe 23.
[0018]
A supply air pipe 20 is connected to an outlet side of the second stage compression section 15, and the supply air pipe 20 is connected to the dehumidifying / reheating device 12 side. In this dehumidifying and reheating device 12, the supply air line 20 coming out from the compressor 11 is connected to the high temperature side of the reheating heat exchanger 21 and comes out from the high temperature side of the reheating heat exchanger 21. The air supply pipe 20 a is further connected to the after cooler 22. The aftercooler 22 is cooled by heat exchange with the cooling water supplied from the cooling water supply pipe 18 and the return pipe 19 branched from the cooling tower CT. The water supplied through the cooling water supply pipe 18 is the same temperature as described above, that is, about 10 to 32 ° C., and is about 32 ° C. in the design. The water returning to the cooling tower CT through the return line 19 is, for example, about 15 ° C. to 42 ° C., and is set to about 37 ° C. in the design.
[0019]
The air supply line 20b coming out from the aftercooler 22 is further connected to a heat exchanger 24 using well water. The heat exchanger 24 is connected to connection pipes 23a and 23b branched from the make-up water pipe 23, and the compressed air that has come out of the aftercooler 22 is well water (make-up water before being supplied to the cooling tower CT). ) And further dehumidified. The temperature of the well is, for example, about 15 ° C. to 20 ° C., and about 20 ° C. in the design.
[0020]
The air supply pipe line 20c coming out from the heat exchanger 24 returns to the low temperature side of the reheat heat exchanger 21 described above so as to exchange heat with the compressed air before being cooled by the aftercooler 22. It is connected to the. The air supply pipe 20d coming out from the low temperature side of the reheat heat exchanger 21, that is, the pipe coming out from the dehumidifying reheater 12, is finally connected to a target pipe such as a factory pipe. .
[0021]
The air supply line 20c before entering the low temperature side of the heat exchanger 21 for reheating and the air supply line 20d after exiting are connected by a bypass line 25, and the flow rate is in the middle. An adjustment valve V1 is interposed. The opening / closing actuator of the flow rate adjusting valve V1 can transmit a signal to the temperature control device TIC1 so that the opening degree is adjusted by a signal from the temperature sensor T that detects the temperature of the air supply pipe line 20d from the exit. It is connected. The signal used is usually an electrical signal, but may be other signals such as a pressure signal. In the temperature control device TIC1, when the temperature of the compressed air in the air supply pipe 20d becomes higher than a predetermined temperature, the flow rate of the compressed air that does not pass through the reheat heat exchanger 21 is increased by increasing the flow rate of the bypass pipe 25. The flow rate is increased and the temperature of the compressed air exiting from the dehumidifying / reheating device 12 is lowered. On the contrary, when the temperature is lowered, the flow rate of the bypass pipe 25 is controlled to be reduced. The temperature range to be adjusted varies depending on the purpose of the compressed air, but is set to a preferable range for increasing the internal energy by thermal expansion, for example, 50 ° C to 60 ° C.
[0022]
The temperature sensor T is preferably installed in the vicinity of a use point where the supply air is consumed, and detects the temperature of the compressed air at the use point. Thereby, the compressed air adjusted with the temperature control apparatus TIC1 so that it may become the optimal temperature in a use point can be supplied.
[0023]
As described above, the makeup water pipe 23 for supplying well water (makeup water) to the cooling tower CT is connected to the cooling tower CT after passing through the connection pipelines 23a and 23b and the heat exchanger 24. Then, a bypass line 27 is provided to connect between the connection line 23a before entering the heat exchanger 24 and the connection line 23b after exiting, and a flow rate adjusting valve V2 is interposed in the middle. This flow rate adjusting valve V2 uses the sensors T1 and T2 for detecting the temperature of the well water and the temperature of the cooling water from the cooling tower and the control device TIC2 to supply makeup water (well water) to the heat exchanger 24 when T2 <T1. Control to bypass without passing. However, there is no need to provide a bypass line or a flow rate adjusting valve.
[0024]
In the dehumidifying / reheating device 12 configured as described above, the compressed air supplied from the compressor 11 is cooled by the reheating heat exchanger 21. The temperature of the compressed air is, for example, 180 ° C. to 220 ° C., particularly 200 ° C., and decreases from that temperature to about 165 ° C. The compressed air is further cooled by the aftercooler 22, and is cooled to, for example, 35 ° C to 45 ° C, particularly to 37 ° C. Further, the compressed air is cooled to, for example, 20 ° C. to 30 ° C., particularly 25 ° C. in the heat exchanger 24 using well water. By such a series of cooling, the moisture contained in the compressed air is condensed into water droplets and discharged through the drain. As a result, compressed air that has been dried to the extent that condensation does not occur in the pipeline is supplied.
[0025]
Furthermore, in said embodiment, the compressed air which comes out from the heat exchanger 24 using well water is heated by the reheat heat exchanger 21, for example to 50 to 70 degreeC, especially to 60 degreeC. As a result, the volume of compressed air expands at an absolute temperature ratio, and the energy that can be supplied increases. If the pressure is constant, the volume increases. If the volume is limited, the pressure increases. For example, when the air cooled to 25 ° C. by the heat exchanger 24 using well water is heated to 60 ° C. by the heat exchanger 21 for reheating, it will thermally expand to (60 + 273) / (25 + 273) ≈1.15. If the pressure is constant, the volume of compressed air delivered will increase by about 15%. That is, the energy to be sent is increased by about 15%, and the power for operating the compressor 11 can be reduced correspondingly as compared with the case where reheating is not performed. Thereby, it can contribute to labor saving and reduction of carbon dioxide emission. Furthermore, since the relative humidity of the compressed air supplied simply by heating of the reheat heat exchanger 21 is lowered, there is an advantage that dew condensation in the air supply pipe 20d hardly occurs. As described above, by using the heat exchanger 21 for reheating, the heat energy exchanged by the aftercooler and radiated to the atmosphere by the cooling tower can be effectively used, and the compressor power can be reduced. Can do.
[0026]
Next, the operation of dehumidifying the compressed air with the dehumidifying and reheating device 12 will be described with reference to FIG. The horizontal axis x in FIG. 2 is the temperature t of the compressed air, and the vertical axis y is the absolute humidity. And the 1st curve S1 shown with a broken line is a curve which shows saturated steam (dew point) when compressed air is 7K. A second curve S2 indicated by a solid line shows a state in which the temperature and humidity of the compressed air that has entered the dehumidifying / reheating device 12 change due to cooling and heating. That is, the compressed air immediately after coming out of the compressor 11 is a point (temperature 200 ° C., absolute humidity 20 g / kg) indicated by the symbol J1 on the second curve S2, as indicated by an arrow N as it is cooled by the aftercooler. Reduces temperature and humidity. In addition, the code | symbol R on 2nd curve S2 shows having cooled by using for reheating. However, this cooling load is small.
[0027]
When the compressed air crosses the first curve S1 (symbol J2), that is, after decreasing to the dew point (temperature 37 ° C., absolute humidity 5.8 g / kg), the position of the symbol J3 is further determined by a heat exchanger using well water. It is cooled to (about 25 ° C.). As a result, the absolute humidity is reduced to about 2.9 g / kg. When heated to about 60 ° C. by reheating in this state, the absolute humidity does not change, the relative humidity decreases to about 10 to 20%, and dry compressed air is obtained. In the graph of FIG. 2, the symbol K is the outside air temperature (for example, 33 ° C.), and the absolute humidity of the supplied compressed air is below the dew point at this point. Condensation does not occur.
[0028]
Incidentally, the symbol J4 in FIG. 2 shows the case where the compressed air is dehumidified by the conventional refrigeration dryer as shown in FIG. 5, and is cooled to a temperature much lower than the level for preventing the condensation of the pipeline. I understand. In that case, the volume reduction is increased by excessive cooling.
[0029]
FIG. 3 is a graph showing a comparison of the dehumidifying action of the dehumidifying / reheating device 12 of FIG. 1 and the refrigeration dryer 102 of FIG. The compressed air supplied from the compressors 11 and 101 both contains dry air (dry air) A and moisture W. In the dehumidifying / reheating device 12 of FIG. 1, the moisture corresponding to the symbol W1 is dehumidified out of the moisture W, and therefore the air supply after dehumidification is A + W2. On the other hand, the refrigeration dryer 102 dehumidifies the moisture corresponding to the symbol W3, so that the air supply amount is A + W4. Therefore, if the dehumidification is sufficient to prevent dew condensation on the pipe line, the refrigeration dryer produces so-called “W2-W4” excessive dehumidification. As for the necessary power, the dehumidifying and reheating device 12 in FIG. 1 requires less because the refrigerator is unnecessary.
[0030]
By combining cooling dehumidification with cooling tower CT and aftercooler 22 as described above, cooling dehumidification with heat exchanger 24 using well water, and further reheating and thermal expansion with heat exchanger 21 for reheating, a refrigerator is not used. However, it is possible to achieve dehumidification that does not cause condensation in the pipeline. And combined with the use of thermal expansion due to reheating, the amount of air supply can be increased and the power can be reduced as compared with the case of using a refrigerator.
[0031]
  In the embodiment of the dehumidifying and reheating device described above, the compressed air before supply is reheated by the heat exchanger 21 for reheating. However, in some cases, it may be supplied directly to the pipeline for use without reheating. .In that case, it is outside the scope of the present invention.Even in that case, wellWaterThe above-mentioned effects such as reduction of power consumption and suppression of excessive volume reduction based on cooling and dehumidification of compressed air with the replenishing water of the cooling tower can be achieved. In that case, it becomes a dehumidifying device instead of a dehumidifying reheat device.
[0032]
The compressed air supply system 30 shown in FIG. 4 is substantially the same except that two cooling towers CT1 and CT2 are provided, and that the heat exchanger 24 and the aftercooler 22 are provided integrally in one dehumidifying tower 31. Specifically, it is the same as the system 10 of FIG. In this system 30, the cooling tower is divided into a first cooling tower CT 1 that supplies cooling water to the compressor 11 and a second cooling tower CT 2 that supplies cooling water to the aftercooler 22. However, as in the case of FIG. 1, one unit may supply cooling water to both. These cooling towers may be either a closed type or an open type. The dehumidifying tower 31 is provided with a pipe line 32 for temporarily raising the compressed air introduced from below as indicated by an arrow P. The aftercooler 22 is combined with a heat exchanger 24 provided on the lower side thereof, and the compressed air once raised is sequentially passed through the aftercooler 22 and the heat exchanger 24 to be cooled. Reference numeral 33 denotes a demister for removing water droplets in the compressed air, and reference numeral 34 denotes a filter provided in the air supply pipe 20d.
[0033]
That is, in this cooling and dehumidifying tower 31, the compressed air from the compressor 11 is first cooled by exchanging heat with the cooling water supplied from the second cooling tower CT 2 in the aftercooler 22, and then cooled in the heat exchanger 24. Supercooled with water. In the middle of ascending, moisture is removed by the demister 33 and dehumidified. Further, the dehumidified compressed air is heated by the reheat heat exchanger 21 to expand its volume, the amount of compressed air delivered increases, and condensation in the pipe is further prevented. Further, by integrating the heat exchanger 24 and the aftercooler 22 with one cooling / dehumidifying tower 31, the apparatus becomes compact. Further, by making the cooling and dehumidifying tower 31 a pressure-resistant tank, an air buffer function that suppresses pressure pulsation is achieved. Therefore, it is not necessary to provide a separate air buffer.
[0034]
【Example】
Next, specific examples of the dehumidifying device will be given to explain the operation and effect. This embodiment is based on values designed based on a general environment and required specifications.
(A) [Effect of heat exchange using well water]
The temperature of the compressed air cooled by the aftercooler (dew point temperature) is
tab = cooling water inlet temperature (tw) + α
It can be expressed as. Where α is the temperature difference between the compressed air and the cooling water after heat exchange. When the outside air conditions are an air temperature of 33 ° C., a humidity of 63%, and a wet bulb temperature (wB) of 27 ° C., the cooling water feed to the after cooler is tw 32 ° C. If the temperature difference α is 5 ° C., the temperature of the compressed air coming out of the aftercooler is
tab = 37 ° C. (32 + 5 ° C.)
It becomes. This state corresponds to the symbol J2 in FIG. Absolute humidity X at this time_ab= 5.8 (g / kg '). Furthermore, when cooling and dehumidifying to below ambient temperature (for example, outside temperature 33 ° C. or more) with well water (20 ° C.), the temperature difference with well water can be cooled to 5 ° C.
tab ′ = 25 ° C. (20 ° C. + 5 ° C.)
Can be dehumidified by cooling. This state corresponds to the symbol J3 in FIG. Absolute humidity X at this time_ab'= 2.9 (g / kg'). As can be seen from this example, cooling by an aftercooler using a cooling tower alone has a considerable dehumidifying effect, but when combined with heat exchange using well water, a sufficient dehumidifying effect can be obtained to prevent dew condensation in the pipeline. Can do.
[0035]
(B) [Water quantity balance] Compressor 600kw, air quantity Qa6,000Nm^Three/ H
Well water volume (V1) = Required cooling volume q₁÷ 10 ℃ (utilization temperature difference).

(However, the latent heat of vaporization of water is 600 kcal / kg). Therefore
Required cooling amount (q₁) = (1) + (2) = 33,400 kcal / h
Therefore, heat capacity of water 1m^Three: From 1,000 kcal / ° C
Required water volume (V₁) = 33,400 ÷ 1,000 ÷ 10 = 3.34m^Three/ H
It becomes.
[0036]
Cooling water volume (V₂) = Intercooler cooling water volume V₂'+ Aftercooler cooling water amount V ".
Intercooler cooling water volume (V₂′) = Intercooler cooling amount q₂'÷ 6 ° C (utilization temperature difference). When the inlet air temperature of the intercooler is 155 ° C and the outlet air temperature is 40 ° C,
Intercooler cooling amount (q₂′) = 6,000 × 1.2 × 0.24 × (155-40) ≈199,000 kcal / h
It becomes. Therefore, 10% heat loss is expected.
Intercooler cooling water volume (V₂′) = 199,000 ÷ 1,000 ÷ 6 × 1.1≈36.5 m^Three/ H
When we expect about 20% of cooling for oil coolers,
V₂'= 36.5 × 1.2 = 44 m^Three/ H
It becomes.
[0037]
On the other hand, aftercooler cooling water volume (V₂“) = After-cooler cooling amount q_Three'÷ 5 ° C (utilization temperature difference).
Aftercooler cooling amount (q_Three) = 6,000 × 1.2 × 0.24 × (175-37) ≈239,000 kcal / h
Therefore, expecting 10% heat loss,
Aftercooler cooling water volume (V₂") = 239,000 ÷ 1,000 ÷ 5 × 1.1 ≒ 53m^Three/ H
It becomes. Therefore
Cooling water volume (V₂) = V₂'+ V₂"= 44 + 53 = 97m^Three/ H
It is.
[0038]
Usually, the intercooler and the aftercooler are designed with a cooling water utilization temperature difference in the range of 5 to 10 ° C., and there is no problem with the above utilization temperature difference.
[0039]
Cooling water flow required for intercooler and aftercooler V₂  The ratio of the flow rate V1 of the well water to V1 / V2 = 3.34 / 97≈0.034 = 3.4%. Thus, the necessary amount of well water is about 3.4% of the cooling water flow rate, which is almost the same as the amount of cooling tower that is normally required. In other words, it is sufficient to effectively use the cold heat of the make-up water that has been wasted.
[Brief description of the drawings]
FIG. 1 is a piping system diagram showing an entire compressed air supply system equipped with a dehumidifying and reheating device of the present invention.
FIG. 2 is a graph showing the operation of the dehumidifying and reheating device of the system of FIG.
FIG. 3 is a graph showing the operation of the heat exchanger for reheating of the system of FIG.
FIG. 4 is a piping diagram showing another embodiment of a compressed air supply system equipped with the dehumidifying device of the present invention.
FIG. 5 is a piping diagram showing an example of a conventional compressed air supply system.
6 is a schematic view of a compressed air dehumidification / deoiling device of Non-Patent Document 1. FIG.
[Explanation of symbols]
10 Compressed air supply system
11 Compressor
12 Dehumidification reheat device
14 First stage compression section
15 Second stage compression section
16 pipelines
17 Intercooler
M motor
CT cooling tower
18 Cooling water supply pipeline
19 Return pipeline
20, 20a, 20b, 20c, 20d Supply air line
21 Heat exchanger for reheating
22 After cooler
23 makeup water pipeline
23a, 23b Connection pipeline
24 Heat exchanger using well water
25 Bypass pipeline
V1 flow adjustment valve
T temperature sensor
TIC1 temperature controller
V2 flow adjustment valve
TIC1, TIC2 Temperature controller
27 Bypass line
30 Compressed air supply system
CT1 1st cooling tower
CT2 2nd cooling tower
31 Cooling dehumidification tower
32 pipelines
33 Demister
34 Filter
101 Compressor
102 Refrigeration dryer
103 First stage compression section
104 Second stage compression section
105 Intercooler
CT1, CT2 Cooling tower
107 Supply air line
108 Aftercooler
109 makeup water pipeline
110 pump
112 Evaporator
113 Condenser
114 Reheater
116 heat exchanger
117 Evaporation valve
120 Compressed air dehumidification and deoiling equipment
121 Cooling Tower
122 Cooling water circulation pump
123 Cooling dehumidification tower
124 Air inlet
125 Air outlet
126 Drain

Claims (2)

Used a two-stage compressor for supplying compressed air, a dehumidifying reheating device comprising an after cooler to the cooling water and compressed air to the heat exchanger supplied by a cooling tower,
A supply air line for passing compressed air supplied from the second stage compression section of the compressor ;
And replenishing water lines for supplying well water in the cooling tower,
And aftercooler you heat exchange with the cooling water from the interposed midway of the supply air duct, the compressed air in the supply air duct cooling tower,
Provided on the downstream side of the aftercooler, a heat exchanger for exchanging heat between the compressed air supply air duct after the aftercooler and makeup water supply water conduit,
Includes a reheat heat exchanger for heat exchange between the hot air from its heat exchanger comes out the supply air coming out of the second stage of the compressor,
The supply air line is adapted to convert the high-temperature compressed air that has come out of the second-stage compression section of the compressor into the high-temperature side of the reheat heat exchanger, the aftercooler, the heat exchanger, and the reheat heat exchanger. In order of the low temperature side,
The heat exchanger is connected to a replenishing water line for replenishing well water to the cooling tower and an aftercooler outlet side of the supply air line, and is supplied to the cooling tower and compressed air coming out of the aftercooler. Exchange heat with the replenishing water before
The reheat heat exchanger is a dehumidification reheat device for compressed air that exchanges heat between the supply air coming out of the heat exchanger and the high temperature air on the outlet side of the second-stage compression section . A bypass line is connected between the air supply line before entering the low temperature side of the heat exchanger for reheating and the air supply line after exiting,
A flow control valve is provided in the middle of the bypass line,
The actuator of the flow rate adjusting valve causes the temperature of the compressed air in the air supply line to become a predetermined temperature based on a signal from a temperature sensor that detects the temperature of the air supply line or a use point where the supply air is used. The dehumidifying and reheating apparatus for compressed air according to claim 1, wherein the opening degree is adjusted as described above .

Images