JP2018062878A - Water addition type compressor system and heat recovery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water addition type compressor system and a heat recovery system including the water addition type compressor system, capable of properly preventing generation of scale without causing significant cost-up.SOLUTION: A water addition type compressor system 1 includes a water addition type compressor 2, a separator tank 3 for separating a compressed fluid discharged from the compressor 2 into a gas and water, a circulation line L3 for circulating additive water between the compressor 2 and the separator tank 3, a water supply line L2 for circulating the water to be added to the compressor 2, and a hard water softening device 60 disposed in the water supply line L2 to manufacture softened water of a total hardness of 1 mg CaCO/L or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water addition type compressor system and a heat recovery system.

  Conventionally, a water addition type compressor system that compresses air to which water has been added is known (for example, see Patent Document 1). The water addition type compressor system includes a compressor that compresses a fluid such as air using the added water (added water) as a lubricant sealant, and a separator tank that performs air-water separation of the compressed fluid discharged from the compressor. And a circulation line for circulating the added water between the compressor and the separator tank.

  The added water used as the lubricant sealant in the compressor is separated from the compressed fluid in the separator tank, and then returned to the compressor through the circulation line, where it is used again as the lubricant sealant. Further, since the added water gradually decreases during repeated use, the added water is replenished at a predetermined timing.

JP 2011-163219 A

  By the way, if the added water contains a lot of hardness components, scales (for example, calcium carbonate scales and calcium silicate scales) are generated in the compressor, separator tank, circulation line, etc. It becomes a cause. Therefore, a water addition type compressor system in which a pure water device (for example, a two-bed two-column ion exchange device, a reverse osmosis membrane device, etc.) is arranged in the supply line of the additive water and pure water is used as the additive water has been proposed. Yes.

  However, if the water addition type compressor system includes a pure water device, the maintenance and management of the pure water device becomes complicated, and the operation of the water addition type compressor system is costly.

  Accordingly, an object of the present invention is to provide a water addition type compressor system that can suitably prevent generation of scale without causing a significant increase in cost, and a heat recovery system including the water addition type compressor system.

The present invention includes a water addition type compressor, a separator tank that separates compressed water discharged from the compressor, and a circulation line that circulates addition water between the compressor and the separator tank. A water addition type compressor system comprising: a water supply line through which water added to the compressor flows; and a hard water softening device that is disposed in the water supply line and produces softened water having a total hardness of 1 mgCaCO ₃ / L or less. About.

  The water addition type compressor system includes an after cooler that recovers heat from compressed air, a water cooler that is disposed in the circulation line and recovers heat from the added water, and an upstream side downstream of the water softening device in the water supply line. It is preferable to further comprise a cooling water line that is connected to the aftercooler and supplies the cooling water to the water cooler.

  The water addition type compressor system further includes a pre-separator that is disposed between the compressor and the separator tank and performs pre-air / water separation on the upstream side of the separator tank, and the circulation line includes the compressor And a first discharge line connecting the pre-separator, a second discharge line connecting the gas phase part of the pre-separator and the gas phase part of the separator tank, the liquid phase part of the pre-separator and the separator tank A third discharge line that connects the liquid phase part of the gas tank and a return line that returns the added water stored in the separator tank to the compressor, and the aftercooler is disposed in the second discharge line, The water cooler is preferably disposed in the third discharge line.

  Moreover, it is preferable that the said water softening apparatus manufactures the softened water whose electric conductivity is 150 mS / m or less.

  Moreover, it is preferable that the said water softening apparatus is equipped with Na type | mold cation exchange resin, and softens the water containing a hardness component by this Na type | mold cation exchange resin.

  The present invention also relates to a heat recovery system including the above-described water addition type compressor system and a steam boiler connected to the downstream side of the cooling water line.

  ADVANTAGE OF THE INVENTION According to this invention, the heat recovery system provided with the water addition type compressor system and this water addition type compressor system which can prevent generation | occurrence | production of a scale suitably without causing a significant cost increase can be provided.

It is a figure which shows the structure of 1st Embodiment of a heat recovery system provided with the water addition type compressor system of this invention. It is a figure which shows the structure of 2nd Embodiment of a heat recovery system provided with the water addition type compressor system of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The “line” in the present specification is a general term for lines capable of flowing a fluid such as a flow path, a path, and a pipeline.

FIG. 1 is a schematic diagram illustrating a configuration of a heat recovery system 100 including a water addition type compressor system 1 according to the first embodiment of the present invention.
As shown in FIG. 1, the heat recovery system 100 of the first embodiment includes a water addition type compressor system 1 and a steam boiler 70.
The water addition type compressor system 1 includes a water addition type compressor 2, an electric motor 20 as a prime mover of the compressor 2, a separator tank 3 that performs air-water separation of compressed air discharged from the compressor 2, An aftercooler 34 that cools and recovers the compressed air separated from the air in the separator tank 3, a water cooler 25 that cools and recovers the added water separated from the air in the separator tank 3, and a water-added compression A water softening device 60 for softening water used in the machine system 1 and a degassing device 61 for degassing water softened in the water softening device 60 are provided as main components.

  In addition, the heat recovery system 100 of the present embodiment includes an air supply line L1, a water supply line L2, a circulation line L3, a compressed air delivery line L4, and an air release as lines through which fluids such as water and air circulate. A line L5, a drain line L6, a cooling water line L7, and a boiler water supply line L8 are provided.

<Compressor>
The compressor 2 is a water addition type air compressor. The compressor 2 of 1st Embodiment is comprised by the scroll type, and compresses air and discharges the compressed air containing addition water by rotating a turning scroll with respect to a fixed scroll (all are not shown). . In the present embodiment, a scroll fluid machine of a type in which orbiting wraps are provided on both side surfaces of the orbiting scroll and a pair of fixed scrolls are arranged so as to sandwich the orbiting scroll is used. In addition, the compressor 2 can use things other than a scroll type, for example, a screw type compressor.

  An electric motor 20 is used as a drive source of the compressor 2 of the present embodiment. The rotation speed of the electric motor 20 is controlled by the drive frequency output from the inverter 21. In addition, as a drive source, things other than the electric motor 20, for example, a steam engine (for example, a scroll type expander) driven by steam can be used.

<Separator tank>
The separator tank 3 is a steam separator that separates water from compressed air. The separator tank 3 is supplied with compressed air containing water from the compressor 2, and is separated into compressed air and water by the separator tank 3. The interior of the separator tank 3 is divided into an upper gas phase portion and a lower liquid phase portion by air-water separation.

  The separator tank 3 is provided with a water level detector 32 that detects the internal water level. The water level detector 32 detects the water level inside the separator tank 3. The configuration of the water level detector 32 is not particularly limited, and a float type or electrode type level switch, a capacitance type level sensor, or the like is used. In the present embodiment, a water level detector 32 capable of detecting a low water level, a middle water level, and a high water level is used.

Next, each line and devices arranged in each line will be described.
The compressor 2 is supplied with air as a fluid to be compressed from the air supply line L1 and supplied with added water from the water supply line L2. Further, between the compressor 2 and the separator tank 3, the added water is circulated by the discharge line L31 and the return line L32 as the circulation line L3.

  The air supply line L <b> 1 sucks outside air and supplies the sucked air to the compressor 2. An air filter 22 is disposed in the air supply line L1, and clean air that has passed through the air filter 22 is supplied to the compressor 2.

  The water supply line L2 has an upstream end connected to a water supply source (not shown) and a downstream side connected to the downstream side of the air filter 22 in the air supply line L1. The water supply line L2 supplies added water to the compressor 2 through the air supply line L1. In the water supply line L2, a water softening device 60, a deaeration treatment device 61, and a water supply valve 24 are arranged in this order from the upstream side.

The hard water softening device 60 softens water (hard water) supplied from a water supply source to produce soft water. The hard water softening device 60 removes and reduces hardness components contained in the supplied water, specifically, calcium ions and magnesium ions, and produces softened water.
In the present embodiment, the water softening device 60 produces softened water having a total hardness of 1 mg CaCO ₃ / L or less. By using softened water with a total hardness of 1 mg CaCO ₃ / L or less as added water, even if the hydrogen carbonate ion concentration or silica concentration of the added water is high due to the hard water, the scale in the water added compressor system 1 Generation of (calcium carbonate scale, calcium silicate scale) can be effectively suppressed. Moreover, the hard water softening device 60 produces softened water having an electric conductivity of 150 mS / m or less by softening hard water having an electric conductivity of 150 mS / m or less. By using softened water with an electric conductivity of 150 mS / m or less as added water, water is added even when the corrosive ion concentration (chloride ion concentration and sulfate ion concentration) of the added water is high due to hard water. The occurrence of corrosion in the compressor system 1 can be effectively suppressed.

The water softening device 60 is not particularly limited as long as it can be regenerated when the ability to remove a softening treatment material such as an ion exchange resin is lowered. The water softening device 60 is particularly preferably a cation exchange device that performs a softening treatment by performing ion exchange using a single bed made of a Na-type cation exchange resin that has been regenerated with a sodium salt. The regeneration method of the water softening device 60 is a split flow regeneration method capable of reliably obtaining softened water having a total hardness of 1 mg CaCO ₃ / L or less and an electric conductivity of 150 mS / m or less for hard water having high hardness and high electrical conductivity. It is desirable to use a countercurrent regeneration system.

The deaeration treatment device 61 is disposed on the downstream side of the water softening device 60 in the water supply line L2, and degasses the dissolved oxygen contained in the softened water produced by the water softening device 60 using the gas separation membrane module. As the gas separation membrane module, an internal perfusion gas separation membrane module made of a hollow fiber membrane can be used.
In the present embodiment, the deaeration treatment device 61 produces deaerated softened water having a dissolved oxygen concentration of 0.5 mg / L or less. By using degassed softened water having a dissolved oxygen concentration of 0.5 mg / L or less as the added water, the occurrence of corrosion in the water addition type compressor system 1 can be effectively suppressed.

  The water supply valve 24 is configured by, for example, an electromagnetic valve. By opening and closing the water supply valve 24, supply of the added water to the compressor 2 through the water supply line L2, stop, and adjustment of the flow rate are performed.

The circulation line L3 includes a discharge line L31 and a return line L32.
The discharge line L31 connects the compressor 2 and the gas phase part of the separator tank 3, and supplies compressed air containing water discharged from the compressor 2 to the separator tank 3. A check valve 31 is disposed in the discharge line L31. In addition, the discharge line L31 of 1st Embodiment becomes a path | route which takes out compressed air from each of the both-side scroll mechanism of the compressor 2, merges, and sends it to the separator tank 3, and the non-return valve 31 merges here. Arranged downstream of the part.

  The return line L32 connects the liquid phase part of the separator tank 3 and the downstream side of the air filter 22 in the air supply line L1. The return line L32 supplies water generated by the air / water separation in the separator tank 3 to the compressor 2 as additive water through the air supply line L1. Thereby, the added water separated from the steam in the separator tank 3 is reused.

In the return line L32, a water cooler 25, a water filter 23, and an addition water valve 30 are arranged in this order from the upstream side.
The water cooler 25 performs heat exchange between water flowing through the return line L32 and cooling water flowing through a cooling water line L7 described later, and recovers heat while removing heat of compression absorbed by the added water.
The water filter 23 filters the water flowing through the return line L32.
The additive water valve 30 is constituted by, for example, an electromagnetic valve. Supplying, stopping, and adjusting the flow rate of the added water to the compressor 2 through the return line L32 by opening and closing the added water valve 30.

The compressed air delivery line L4 is connected to the gas phase portion of the separator tank 3 on the upstream side, and supplies the compressed air separated in the separator tank 3 to the compressed air using device (not shown). In the compressed air delivery line L4, a primary pressure adjusting valve 33 and an after cooler 34 are arranged in order from the upstream side.
The primary pressure adjustment valve 33 holds the internal pressure of the separator tank 3 at a set pressure.
The aftercooler 34 performs heat exchange between the compressed air flowing through the compressed air delivery line L4 and the cooling water flowing through the cooling water line L7 described later, and removes the heat of compression generated in the air compression process. Heat recovery.

The upstream side of the air release line L5 is connected to the gas phase part of the separator tank 3. An air release valve 40 and a safety valve 42 that open the inside of the separator tank 3 to the atmosphere (outside) are disposed in the air release line L5.
The air release valve 40 is an electromagnetic valve that operates in response to a command from a control unit (not shown). When the air release valve 40 is opened, the inside of the separator tank 3 is opened to the atmosphere. While the compressor 2 is in operation, the air release valve 40 is controlled to be closed.
The safety valve 42 is activated when the internal pressure of the separator tank 3 becomes equal to or higher than a predetermined value, and opens the air release line L5.

  The upstream side of the drainage line L6 is connected to the liquid phase part of the separator tank 3. A drain valve 50 is disposed in the drain line L6. The drain valve 50 is constituted by, for example, an electromagnetic valve. By opening the drain valve 50, the water inside the separator tank 3 is discharged to the outside through the drain line L6.

  The upstream side of the cooling water line L7 is connected to the downstream side of the deaeration device 61 in the water supply line L2, and supplies cooling water to the aftercooler 34 and the water cooler 25. In other words, the softened water softened by the hard water softening device 60 and degassed by the deaeration treatment device 61 flows through the cooling water line L7 as cooling water. And the cooling water which distribute | circulates the cooling water line L7 performs heat recovery from the addition water in the water cooler 25, after recovering heat from compressed air in the aftercooler 34. FIG.

A motor valve 35 is disposed upstream of the aftercooler 34 in the cooling water line L7. By adjusting the opening degree of the motor valve 35, the flow rate of the cooling water flowing through the cooling water line L7 is controlled.
The downstream side of the cooling water line L7 is connected to the boiler feed water line L8, and the cooling water that has flowed through the cooling water line L7 and has recovered heat is used as the preheated boiler feed water through the boiler feed water line L8. To be supplied.

The boiler water supply line L8 has an upstream side connected to the downstream side of the deaeration processing device 61 in the water supply line L2, and a downstream side connected to the steam boiler 70. In the boiler water supply line L8, when the operation of the water addition type compressor system 1 is stopped and the heat recovery by the heat recovery system 100 is also stopped (that is, when the water supply valve 24 and the motor valve 35 are closed), etc. Furthermore, it functions as a bypass line that supplies the softened water softened by the hard water softening device 60 and degassed by the deaeration treatment device 61 to the steam boiler 70 as boiler feed water.
A motor valve 36 is disposed in the boiler water supply line L8. By opening and closing the motor valve 36, water supply, stop, and flow rate adjustment to the steam boiler 70 through the boiler water supply line L8 are performed.

  The steam boiler 70 generates steam by heating water supplied from a water supply source. In 1st Embodiment, the steam boiler 70 produces | generates a vapor | steam using the cooling water (warming water) which distribute | circulated the cooling water line L7, and / or the water (normal temperature water) which distribute | circulates the boiler feed water line L8. In addition, a water supply tank (not shown) is provided in the previous stage of the steam boiler 70.

Next, operations of the water addition type compressor system 1 and the heat recovery system 100 of the first embodiment will be described.
During operation of the water addition type compressor system 1, the electric motor 20 is driven through the inverter 21 in the compressor 2, and the air to which water is added is compressed. The compressed air containing water discharged from the compressor 2 is sent to the separator tank 3 through the discharge line L31, and is separated into compressed air and water by the separator tank 3. The compressed air separated in the separator tank 3 flows through the compressed air delivery line L4, is cooled by the aftercooler 34, and is then sent to the equipment using compressed air. The water separated in the separator tank 3 is cooled by the water cooler 25 in the return line L32, filtered by the water filter 23, and then reused in the compressor 2 through the air supply line L1. The cooling water flowing through the cooling water line L7 is supplied to the steam boiler 70 after the compressed air and water (added water) are cooled and recovered in the aftercooler 34 and the water cooler 25.

Here, in a state where the water addition type compressor system 1 is in operation, the motor valve 36 of the boiler water supply line L8 is closed. In addition, the opening and closing of the water supply valve 24 of the water supply line L2 and the motor valve 35 of the cooling water line L7 are controlled according to the driving state of the water addition type compressor system 1.
For example, the water supply valve 24 is opened when the water level of the separator tank 3 detected by the water level detector 32 of the separator tank 3 is lowered, and is closed when the water level is raised. The opening degree of the motor valve 36 is controlled according to the temperature of the cooling water flowing out from the water cooler 25.

  Thus, in a state where the water addition type compressor system 1 is in operation, the water softened by the hard water softening device 60 and degassed by the degassing processing device 61 is compressed as added water through the water supply line L2. In addition to being supplied to the machine 2, it is supplied to the cooling water line L7 as cooling water and used for heat recovery in the aftercooler 34 and the water cooler 25. Moreover, the cooling water which collect | recovered heat | fever in the aftercooler 34 and the water cooler 25 is used as boiler feed water of the steam boiler 70 in the preheated state.

  On the other hand, in a state where the operation of the water addition type compressor system 1 is stopped, the water supply valve 24 of the water supply line L2 and the motor valve 35 of the cooling water line L7 are closed. Then, the motor valve 36 of the boiler water supply line L8 is opened, and the opening degree of the motor valve 36 is controlled according to the water level of a water supply tank (not shown). Thereby, in the state where the operation of the water addition type compressor system 1 is stopped, the water that has been softened by the hard water softening device 60 and degassed by the degassing processing device 61 passes through the boiler water supply line L8. Used as 70 boiler feed water.

Thus, according to the water addition type compressor system 1 and the heat recovery system 100 of the first embodiment, the total hardness of 1 mg CaCO ₃ / L or less manufactured by the water softening device 60 arranged on the upstream side of the water supply line L 2. In accordance with the operation status of the water addition type compressor system 1, the addition water supplied to the compressor 2, the cooling water supplied to the after cooler 34 and the water cooler 25, and the boiler feed water supplied to the steam boiler 70 It can be used for various purposes.

  According to the water addition type compressor system 1 and the heat recovery system 100 of 1st Embodiment demonstrated above, there exist the following effects.

(1) The water addition type compressor system 1 was configured including the water softening device 60. As a result, the added water added to the compressor 2 from the water supply line L2 can be softened water of 1 mgCaCO ₃ / L or less, so that it is effective to generate scale in the compressor 2, the separator tank 3 and the circulation line L3. Can be suppressed. Further, the treatment by the water softening device 60 is removal of the hardness component and does not perform excessive water treatment on the added water, so that no significant cost increase is caused in the operation of the water addition type compressor system 1 and scale is generated. Can be suppressed.

  (2) The water addition type compressor system 1 is connected to the aftercooler 34 for recovering heat from the compressed air, the water cooler 25 for recovering heat from the added water, and the upstream side to the downstream side of the water softening device 60 in the water supply line L2. And a cooling water line L7 for supplying cooling water to the after-cooler 34 and the water cooler 25. Thereby, heat recovery can be performed from the compressed air and the added water using the softened water produced by the water softening device 60. Therefore, in the operation of the water addition type compressor system 1, heat can be effectively used, and the water treated by the hard water softening device 60 can be supplied to the after cooler 34 and the water cooler 25. Effective use of the device 60 can effectively suppress the generation of scale in the aftercooler 34 and the water cooler 25.

  (3) The water softening device 60 was configured to include a Na-type cation exchange resin. Thus, when the hardness component is adsorbed on the Na-type cation exchange resin and the water softening ability (ion exchange ability) is lowered, the Na-type cation exchange resin can be easily regenerated using the sodium salt (NaCl aqueous solution). . Therefore, the operation cost of the water addition type compressor system 1 can be suppressed more.

  (4) The heat recovery system 100 is configured to include the water addition type compressor system 1 and the steam boiler 70 connected to the downstream side of the cooling water line L7. Thereby, since the cooling water used for heat recovery in the water addition type compressor system 1 can be supplied to the steam boiler 70 as preheated boiler feed water, the fuel consumption of the steam boiler 70 can be reduced. Moreover, since heat recovery is performed using the softened water from which the hardness component has been removed by the hard water softening device 60, the cooling water that has been recovered can be supplied to the steam boiler 70 without being treated.

  Next, a second embodiment of the water addition type compressor system and the heat recovery system will be described with reference to FIG. The water addition type compressor system 1A of the second embodiment mainly differs from the first embodiment in that it further includes a pre-separator 8 and a cooling water circulation line L9, and the arrangement of the after cooler 34A and the water cooler 25A. In the description of the second embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted or simplified.

The water addition type compressor system 1 </ b> A according to the second embodiment further includes a pre-separator 8 disposed between the compressor 2 and the separator tank 3.
The pre-separator 8 is disposed between the compressor 2 and the separator tank 3, and performs pre-steam water separation on the upstream side of the separator tank 3. The pre-separator 8 is supplied with compressed air containing water from the compressor 2, and is separated into compressed air and water by the pre-separator 8. The inside of the pre-separator 8 is divided into an upper gas phase portion and a lower liquid phase portion by air-water separation.

  In the second embodiment, the circulation line L3A includes a first discharge line L311A, a second discharge line L312A, a third discharge line L313A, and a return line L32A.

  The first discharge line L311A connects the compressor 2 and the gas phase portion of the pre-separator 8, and supplies compressed air containing water discharged from the compressor 2 to the separator tank 3. A check valve 31 is arranged in the first discharge line L311A.

  The second discharge line L312A connects the gas phase portion of the pre-separator 8 and the gas phase portion of the separator tank 3 and supplies the separator tank 3 with compressed air that has been separated into water and gas by the pre-separator 8.

The third discharge line L313A connects the liquid phase part of the pre-separator 8 and the liquid phase part of the separator tank 3, and supplies water separated by the pre-separator 8 to the separator tank 3.
The return line L32A connects the liquid phase part of the separator tank 3 and the downstream side of the air filter 22 in the air supply line L1 as in the first embodiment.

  In the second embodiment, the aftercooler 34A is disposed in the second discharge line L312A, and the water cooler 25A is disposed in the third discharge line L313A. That is, in the second embodiment, as shown in FIG. 2, the cooling water flowing through the cooling water line L7 first recovers heat from the compressed air flowing through the second discharge line L312A in the aftercooler 34A. In the water cooler 25A, heat is recovered from the water flowing through the third discharge line L313A.

In the cooling water line L7 of the second embodiment, a tank 62, a cooling water pump 63, a check valve 64, a cooling fan 65 and a motor valve 66 are further arranged, and a cooling water circulation line L9 is connected.
The tank 62 is disposed on the downstream side of the motor valve 35. The tank 62 is connected to the downstream side of the cooling water circulation line L9. The tank 62 stores cooling water flowing through the cooling water line L7 and the cooling water circulation line L9.
The cooling water pump 63 is disposed on the downstream side of the tank 62. The cooling water pump 63 sends the cooling water stored in the tank 62 to the downstream side.
The check valve 64 is disposed on the downstream side of the cooling water pump 63 and prevents the reverse flow of the cooling water flowing through the cooling water line L7.

The cooling fan 65 is disposed downstream of the check valve 64 and upstream of the aftercooler 34A. As will be described later, the cooling fan 65 is driven, for example, when the cooling water is circulated and used to cool the cooling water supplied to the aftercooler 34A and the water cooler 25A.
The motor valve 66 is disposed in the vicinity of a connection portion between the cooling water line L7 and the boiler water supply line L8. The motor valve 66 is closed when the coolant is circulated and used, and is opened when the coolant is not circulated.

  The cooling water circulation line L <b> 9 is connected to the downstream side of the water cooler 25 </ b> A in the cooling water line L <b> A and the upstream side of the motor valve 66, and the downstream side is connected to the tank 62. The cooling water circulation line L9 returns the cooling water that has been heat-recovered in the aftercooler 34A and the water cooler 25A to the tank 62 for circulation. A motor valve 67 is disposed in the cooling water circulation line L9. The motor valve 67 is opened when the cooling water is circulated and used, and is closed when the cooling water is not circulated.

Next, the flow of cooling water in a state where the water addition type compressor system 1A of the second embodiment is being operated will be described.
The water addition type compressor system 1A of the second embodiment includes a cooling water circulation mode in which cooling water is circulated and used in a state where the water addition type compressor system 1A is operated, and steam without circulating the cooling water. A cooling water non-circulation mode to be supplied to the boiler 70.

In the cooling water circulation mode, the motor valve 66 of the cooling water line L7 is closed, and the motor valve 67 of the cooling water circulation line L9 is opened. Further, the cooling fan 65 is driven. In this case, the softened water softened by the hard water softening device 60 and degassed by the deaeration treatment device 61 flows through the cooling water line L7 and recovers heat from the compressed air in the aftercooler 34A, and then the water cooler. At 25A, further heat recovery is performed from the added water. Thereafter, the cooling water that has recovered the heat flows through the cooling water circulation line L9, is returned to the tank 62, and is sent again toward the after cooler 34A and the water cooler 25A by the cooling water pump 63. Since the circulated cooling water is heated by removing heat from the compressed air and the added water, it is cooled by the cooling fan 65 and then supplied again to the after cooler 34A and the water cooler 25A.
The above cooling water circulation mode is used when boiler water supply is not required, for example, when the operation of the steam boiler 70 is stopped.

  In the cooling water non-circulation mode, the motor valve 66 of the cooling water line L7 is opened, and the motor valve 67 of the cooling water circulation line L9 is closed. Further, the driving of the cooling fan 65 is stopped. In this case, the softened water softened by the hard water softening device 60 and degassed by the deaeration treatment device 61 flows through the cooling water line L7 and recovers heat from the compressed air in the aftercooler 34A, and then the water cooler. At 25A, further heat recovery is performed from the added water. Thereafter, the cooling water heated by heat recovery is supplied to the steam boiler 70 through the boiler water supply line L8.

  According to the water addition type compressor system 1A and the heat recovery system 100A of the second embodiment described above, the following effects can be obtained in addition to the effects (1) to (4) described above.

  (5) The water addition type compressor system 1A is configured to include the pre-separator 8, and the after cooler 34A is disposed in the second discharge line L312A for supplying compressed air from the pre-separator 8 to the separator tank 3, and the water cooler 25A was disposed in the third discharge line L313A for supplying water from the pre-separator 8 to the separator tank 3. Thereby, even when the water addition type compressor system 1A is configured to include the pre-separator 8, heat recovery can be suitably performed from the compressed air and the addition water using the softened water produced by the hard water softening device 60.

  (6) The water addition type compressor system 1A was configured including the cooling water circulation line L9. Thereby, according to the water supply request | requirement of the steam boiler 70 which uses cooling water as boiler feed water, the cooling water circulation mode which circulates without supplying cooling water to the steam boiler 70, and the steam boiler 70 without circulating cooling water The cooling water non-circulation mode to be supplied can be switched. Therefore, it is possible to realize the water addition type compressor system 1A and the heat recovery system 100A that can flexibly meet the water supply request of the steam boiler 70 (equipment to which cooling water is supplied).

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be modified as appropriate.
For example, in 1st Embodiment and 2nd Embodiment, although the cooling water heat-recovered with the cooling water line L7 of the water addition type compressor system 1 and 1A was used as the boiler feed water of the steam boiler 70, it is not restricted to this. . That is, the heat-recovered cooling water may be used as boiler water supply for a hot water boiler, or may be used for water supply for equipment other than the boiler.

DESCRIPTION OF SYMBOLS 1,1A Water addition type compressor system 2 Compressor 3 Separator tank 8 Pre-separator 25, 25A Water cooler 34, 34A After cooler 60 Hard water softening device 70 Steam boiler 100, 100A Heat recovery system L2 Water supply line L3, L3A Circulation line L7 Cooling water line L32 Return line L311A First discharge line L312A Second discharge line L313A Third discharge line

Claims (6)

A water addition type compressor,
A separator tank for performing air-water separation of the compressed fluid discharged from the compressor;
A circulation line for circulating added water between the compressor and the separator tank;
A water supply line through which water added to the compressor flows;
A water addition compressor system comprising: a hard water softening device that is disposed in the water supply line and produces softened water having a total hardness of 1 mgCaCO ₃ / L or less. An aftercooler that recovers heat from compressed air;
A water cooler arranged in the circulation line and recovering heat from the added water;
The water addition type compressor according to claim 1, further comprising: a cooling water line that is connected to a downstream side of the water softening device in the water supply line and supplies cooling water to the after cooler and the water cooler. system. A pre-separator that is disposed between the compressor and the separator tank and performs pre-air separation on the upstream side of the separator tank;
The circulation line is
A first discharge line connecting the compressor and the pre-separator;
A second discharge line connecting the gas phase part of the pre-separator and the gas phase part of the separator tank;
A third discharge line connecting the liquid phase part of the pre-separator and the liquid phase part of the separator tank;
A return line for returning the added water stored in the separator tank to the compressor,
The aftercooler is disposed in the second discharge line;
The water addition type compressor system according to claim 2, wherein the water cooler is disposed in the third discharge line.   The water addition type compressor system according to any one of claims 1 to 3, wherein the water softening device produces softened water having an electric conductivity of 150 mS / m or less.   5. The water addition type compressor system according to claim 1, wherein the water softening device includes a Na-type cation exchange resin and softens water containing a hardness component with the Na-type cation exchange resin. . The water addition type compressor system according to claim 2 or 3,
And a steam boiler connected to the downstream side of the cooling water line.

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