JP6859656B2 - Water-added compressor system and heat recovery system - Google Patents

Description

The present invention relates to a water-added compressor system and a heat recovery system.

Conventionally, a water-added compressor system that compresses water-added air is known (see, for example, Patent Document 1). The water-added compressor system includes a compressor that compresses a fluid such as air using the added water (added water) as a lubricating sealant, and a separator tank that separates the compressed fluid discharged from the compressor into air-water. , A circulation line for circulating added water between the compressor and the separator tank, and the like.

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

Japanese Unexamined Patent Publication No. 2011-163219

By the way, if the added water contains a large amount of hardness components, scales (for example, calcium carbonate scale and calcium silicate scale) are generated in the compressor, separator tank, circulation line, etc., and the compressor malfunctions. It will be the cause. Therefore, a water addition type compressor system has been proposed in which a pure water device (for example, a two-bed, two-tower ion exchange device, a reverse osmosis membrane device, etc.) is placed on the supply line of the added water and pure water is used as the added water. There is.

However, when the water-added compressor system is configured to include the pure water device, the maintenance and management of the pure water device becomes complicated, and the operation of the water-added compressor system requires a large cost.

Therefore, an object of the present invention is to provide a water-added compressor system capable of suitably preventing scale generation without causing a significant cost increase, and a heat recovery system including the water-added compressor system.

The present invention includes a water addition type compressor, a separator tank that separates the compressed fluid discharged from the compressor into air and water, and a circulation line that circulates the added water between the compressor and the separator tank. includes a water supply line to water added to the compressor flows, a water softening device for producing the water supply is disposed in the line total hardness 1mgCaCO 3 / _L or less of softening water, and the water supply line Relates to a water-added compressor system in which neither a back-penetration membrane device nor an ion exchange device for producing pure water is arranged.

Further, the water addition type compressor system includes an aftercooler that recovers heat from compressed air, a water cooler that is arranged in the circulation line and recovers heat from the added water, and an upstream side is a downstream side of the hard water softening device in the water supply line. It is preferable to further include a cooling water line connected to the after-cooler and supplying cooling water to the water cooler.

Further, the water addition type compressor system further includes a pre-separator which is arranged 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 is the compressor. The first discharge line connecting the pre-separator and the pre-separator, the second discharge line connecting the gas phase portion of the pre-separator and the gas phase portion of the separator tank, the liquid phase portion of the pre-separator and the separator tank. A third discharge line for connecting the liquid phase portion of the above and a return line for returning the added water stored in the separator tank to the compressor are provided, and the aftercooler is arranged in the second discharge line. The water cooler is preferably arranged in the third discharge line.

Further, the hard water softening device preferably produces softened water having an electric conductivity of 150 mS / m or less.

Further, it is preferable that the hard water softening apparatus includes a Na-type cation exchange resin and softens water containing a hardness component with the Na-type cation exchange resin.

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

According to the present invention, it is possible to provide a water-added compressor system capable of suitably preventing scale generation without causing a significant cost increase, and a heat recovery system including the water-added compressor system.

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

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the "line" in this specification is a general term of a line capable of flowing a fluid such as a flow path, a path, and a pipeline.

FIG. 1 is a schematic view showing the configuration of a heat recovery system 100 including a water-added 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-added 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 for separating air and water of compressed air discharged from the compressor 2. An aftercooler 34 that cools the compressed air separated by air and water in the separator tank 3 and recovers heat, a water cooler 25 that cools and recovers heat of the added water separated by air and water in the separator tank 3, and water addition type compression. A hard water softening device 60 for softening water used in the machine system 1 and a degassing treatment device 61 for degassing the softened water in the hard water softening device 60 are provided as main configurations.

Further, in the heat recovery system 100 of the present embodiment, as the lines through which fluids such as water and air flow, the air supply line L1, the water supply line L2, the circulation line L3, the compressed air delivery line L4, and the air release A line L5, a drainage line L6, a cooling water line L7, and a boiler water supply line L8 are provided.

<Compressor>
The compressor 2 is a water-added air compressor. The compressor 2 of the first embodiment is configured as a scroll type, and by rotating a swivel scroll with respect to a fixed scroll (both not shown), air is compressed and compressed air containing added water is discharged. .. In the present embodiment, a scroll fluid machine of a type in which swivel laps are provided on both side surfaces of a swivel scroll and a pair of fixed scrolls are arranged so as to sandwich the swivel scroll is used. As the compressor 2, a compressor other than the scroll type, for example, a screw type compressor can be used.

An electric motor 20 is used as a drive source for 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. As the drive source, a steam engine other than the electric motor 20, for example, a steam engine driven by steam (for example, a scroll type expander) can be used.

<Separator tank>
The separator tank 3 is a brackish water separator that separates water from compressed air. Compressed air containing water is sent from the compressor 2 to the separator tank 3, and the separator tank 3 separates the compressed air into water. The inside of the separator tank 3 is divided into an upper gas phase portion and a lower liquid phase portion by brackish water separation.

A water level detector 32 for detecting the internal water level is arranged in the separator tank 3. 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 this embodiment, a water level detector 32 capable of detecting a low water level, a medium water level, and a high water level is used.

Next, each line and the equipment arranged in each line will be described.
Air is supplied to the compressor 2 as a fluid to be compressed from the air supply line L1, and added water is supplied 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 L1 sucks the outside air and supplies the sucked air to the compressor 2. An air filter 22 is arranged in the air supply line L1, and clean air that has passed through the air filter 22 is supplied to the compressor 2.

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

The hard water softening device 60 softens the water (hard water) supplied from the water supply source to produce softened water. The hard water softening device 60 removes and reduces hardness components, specifically calcium ions and magnesium ions, contained in the supplied water to produce softened water.
In the present embodiment, the hard water softening device 60 _{produces softened water having a total hardness of 1 mgCaCO 3} / L or less. By using softened water with a total hardness of 1 mgCaCO ₃ / L or less as the added water, the scale in the water-added compressor system 1 even when the hydrogen carbonate ion concentration and the silica concentration of the added water are high due to the hard water. The generation of (calcium carbonate scale, calcium silicate scale) can be effectively suppressed. Further, the hard water softening device 60 produces softened water having an electric conductivity of 150 mS / m or less by softening the hard water having an electric conductivity of 150 mS / m or less. By using softened water with an electrical conductivity of 150 mS / m or less as the 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 type compressor system 1 can be effectively suppressed.

The hard water softening device 60 is not particularly limited as long as it can be regenerated when the removing ability of the softening material such as an ion exchange resin is reduced. As the hard water softening device 60, 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 is particularly preferable. The regeneration method of the hard water softening device 60 is a split flow regeneration method capable of reliably obtaining softened water having a _{total hardness of 1 mgCaCO 3 / L or less and an electrical conductivity of 150 mS / m or less with respect to hard water having high hardness and high electrical conductivity.} It is desirable to use a countercurrent regeneration method.

The degassing treatment device 61 is arranged on the downstream side of the hard water softening device 60 in the water supply line L2, and the dissolved oxygen contained in the softened water produced by the hard water softening device 60 is degassed by the gas separation membrane module. As the gas separation membrane module, an internal perfusion type gas separation membrane module made of a hollow fiber membrane can be used.
In the present embodiment, the degassing treatment device 61 produces degassed 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-added compressor system 1 can be effectively suppressed.

The water supply valve 24 is composed of, for example, an electromagnetic valve. By opening and closing the water supply valve 24, the added water is supplied to the compressor 2 through the water supply line L2, stopped, and the flow rate is adjusted.

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 portion 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 arranged on the discharge line L31. The discharge line L31 of the first embodiment is a path in which compressed air is taken out from each of the scroll mechanisms on both sides of the compressor 2 and merged, and then sent to the separator tank 3, and the check valve 31 merges. It is located on the downstream side of the part.

The return line L32 connects the liquid phase portion 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 the water generated by the separation of air and water in the separator tank 3 to the compressor 2 as additional water through the air supply line L1. As a result, the added water separated by brackish water in the separator tank 3 is reused.

A water cooler 25, a water filter 23, and an additive water valve 30 are arranged in this order from the upstream side on the return line L32.
The water cooler 25 exchanges heat between the water flowing through the return line L32 and the cooling water flowing through the cooling water line L7 described later, and recovers heat while removing the 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 composed of, for example, an electromagnetic valve. By opening and closing the additive water valve 30, the additive water is supplied to the compressor 2 through the return line L32, stopped, and the flow rate is adjusted.

The upstream side of the compressed air delivery line L4 is connected to the gas phase portion of the separator tank 3, and the compressed air separated by the separator tank 3 is supplied to a device using compressed air (not shown). In the compressed air delivery line L4, the primary pressure adjusting valve 33 and the aftercooler 34 are arranged in order from the upstream side.
The primary pressure adjusting valve 33 holds the internal pressure of the separator tank 3 at a set pressure.
The aftercooler 34 exchanges heat 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 process of compressing the air. Recover heat.

The upstream side of the air release line L5 is connected to the gas phase portion 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 arranged in the air release line L5.
The air release valve 40 is a solenoid valve that operates according to a command from a control unit (not shown), and when the air release valve 40 is opened, the inside of the separator tank 3 is opened to the atmosphere. During the operation of the compressor 2, the air release valve 40 is controlled to be in the closed state.
The safety valve 42 operates 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 portion of the separator tank 3. A drain valve 50 is arranged in the drain line L6. The drain valve 50 is composed of, for example, a solenoid valve, and 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 degassing treatment device 61 in the water supply line L2, and supplies cooling water to the aftercooler 34 and the water cooler 25. That is, the softened water softened by the hard water softening device 60 and degassed by the degassing treatment device 61 flows to the cooling water line L7 as cooling water. Then, the cooling water flowing through the cooling water line L7 recovers heat from the compressed air in the aftercooler 34, and then further recovers heat from the added water in the water cooler 25.

A motor valve 35 is arranged on the upstream side 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 water supply line L8, and the cooling water that has been circulated through the cooling water line L7 to recover heat is used as preheated boiler water supply and is steam boiler 70 through the boiler water supply line L8. Is supplied to.

The upstream side of the boiler water supply line L8 is connected to the downstream side of the degassing treatment device 61 in the water supply line L2, and the downstream side is 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. In addition, the softened water softened by the hard water softening device 60 and degassed by the degassing treatment device 61 functions as a bypass line to be supplied to the steam boiler 70 as boiler supply water.
A motor valve 36 is arranged in the boiler water supply line L8. By opening and closing the motor valve 36, water is supplied to the steam boiler 70 through the boiler water supply line L8, stopped, and the flow rate is adjusted.

The steam boiler 70 heats the water supplied from the water supply source to generate steam. In the first embodiment, the steam boiler 70 generates steam by using the cooling water (warming water) flowing through the cooling water line L7 and / or the water (normal temperature water) flowing through the boiler water supply line L8. A water supply tank (not shown) is provided in front of the steam boiler 70.

Next, the operation of the water addition type compressor system 1 and the heat recovery system 100 of the first embodiment will be described.
During the operation of the water-added compressor system 1, the electric motor 20 is driven in the compressor 2 via the inverter 21, and the water-added air 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 the compressed air and water in the separator tank 3. The compressed air separated by the separator tank 3 flows through the compressed air delivery line L4, is cooled by the aftercooler 34, and then is sent to the compressed air-using device. Further, the water separated by the separator tank 3 is cooled by the water cooler 25 at the return line L32, filtered by the water filter 23, and then reused by the compressor 2 through the air supply line L1. Further, 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 in the aftercooler 34 and the water cooler 25 to recover heat.

Here, in the 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. Further, 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 drops, and is closed when the water level rises. Further, 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.

As a result, in the 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 treatment device 61 is compressed as added water through the water supply line L2. Along with being supplied to the machine 2, it is supplied as cooling water to the cooling water line L7 and used for heat recovery in the aftercooler 34 and the water cooler 25. Further, the cooling water whose heat has been recovered in the aftercooler 34 and the water cooler 25 is used as boiler water for the steam boiler 70 in a preheated state.

On the other hand, when 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 the water supply tank (not shown). As a result, when the operation of the water addition type compressor system 1 is stopped, the water softened by the hard water softening device 60 and degassed by the degassing treatment device 61 is steam boiler through the boiler water supply line L8. It is used as a boiler water supply for 70.

As described above, according to the water addition type compressor system 1 and the heat recovery system 100 of the first embodiment, the total hardness of 1 mgCaCO ₃ / L or less produced by the hard water softening device 60 arranged on the upstream side of the water supply line L2. The softened water of the above is added water to be supplied to the compressor 2, cooling water to be supplied to the aftercooler 34 and the water cooler 25, and boiler supply water to be supplied to the steam boiler 70 according to the operating condition of the water addition type compressor system 1. It can be used for various purposes.

According to the water-added compressor system 1 and the heat recovery system 100 of the first embodiment described above, the following effects are obtained.

(1) The water-added compressor system 1 was configured to include a hard water softening device 60. As a result, the added water added to the compressor 2 from the water supply line L2 _{can be made into softened water of 1 mgCaCO 3} / L or less, so that it is effective that scale is generated in the compressor 2, the separator tank 3 and the circulation line L3. Can be suppressed. Further, since the treatment by the hard water softening device 60 is the removal of the hardness component and does not excessively treat the added water with water, it does not cause a large cost increase in the operation of the water-added compressor system 1 and causes scale generation. Can be suppressed.

(2) The water addition type compressor system 1 is connected to an aftercooler 34 that recovers heat from compressed air, a water cooler 25 that recovers heat from added water, and the upstream side to the downstream side of the hard water softening device 60 in the water supply line L2. A cooling water line L7 for supplying cooling water to the aftercooler 34 and the water cooler 25 is included. As a result, heat can be recovered from the compressed air and the added water using the softened water produced by the hard 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 aftercooler 34 and the water cooler 25, so that one hard water softening can be performed. By effectively utilizing the device 60, the generation of scale in the aftercooler 34 and the water cooler 25 can be effectively suppressed.

(3) The hard water softening device 60 was configured to contain a Na-type cation exchange resin. As a result, when the hardness component is adsorbed on the Na-type cation exchange resin and the hard water softening ability (ion exchange capacity) decreases, the Na-type cation exchange resin can be easily regenerated by using a sodium salt (NaCl aqueous solution). .. Therefore, the operating cost of the water-added compressor system 1 can be further suppressed.

(4) The heat recovery system 100 includes the above-mentioned water-added compressor system 1 and a steam boiler 70 connected to the downstream side of the cooling water line L7. As a result, the cooling water used for heat recovery in the water-added compressor system 1 can be supplied to the steam boiler 70 as preheated boiler supply water, so that the fuel consumption of the steam boiler 70 can be reduced. Further, since the heat is recovered by the softened water from which the hardness component has been removed by the hard water softening device 60, the cooling water for which the heat recovery has been performed can be supplied to the steam boiler 70 without being treated.

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

The water-added compressor system 1A of the second embodiment further includes a pre-separator 8 arranged between the compressor 2 and the separator tank 3.
The pre-separator 8 is arranged between the compressor 2 and the separator tank 3, and pre-air-water separation is performed on the upstream side of the separator tank 3. Compressed air containing water is sent from the compressor 2 to the pre-separator 8, and the pre-separator 8 separates the compressed air into water. The inside of the pre-separator 8 is divided into an upper gas phase portion and a lower liquid phase portion by brackish water separation.

Further, 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 on 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 compressed air separated by the pre-separator 8 to the separator tank 3.

The third discharge line L313A connects the liquid phase portion of the pre-separator 8 and the liquid phase portion of the separator tank 3 and supplies the water separated by the pre-separator 8 to the separator tank 3.
The return line L32A connects the liquid phase portion 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.

Further, in the second embodiment, the aftercooler 34A is arranged on the second discharge line L312A, and the water cooler 25A is arranged on 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, and then recovers heat. In the water cooler 25A, heat is recovered from the water flowing through the third discharge line L313A.

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

The cooling fan 65 is arranged on the downstream side of the check valve 64 and on the upstream side of the aftercooler 34A. The cooling fan 65 is driven, for example, when the cooling water is circulated and used, as will be described later, and cools the cooling water supplied to the aftercooler 34A and the water cooler 25A.
The motor valve 66 is arranged in the vicinity of the connection portion of the cooling water line L7 with the boiler water supply line L8. The motor valve 66 is closed when the cooling water is circulated and used, and is opened when the cooling water is not circulated.

The upstream side of the cooling water circulation line L9 is connected to the downstream side of the water cooler 25A in the cooling water line L7 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 whose heat has been recovered in the aftercooler 34A and the water cooler 25A to the tank 62 and circulates the cooling water. A motor valve 67 is arranged on 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 the cooling water in the state where the water-added compressor system 1A of the second embodiment is operated will be described.
The water-added compressor system 1A of the second embodiment has a cooling water circulation mode in which cooling water is circulated and used while the water-added compressor system 1A is in operation, and steam without circulating the cooling water. It includes a cooling water non-circulation mode for supplying 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 degassing treatment device 61 is circulated through the cooling water line L7 to recover heat from the compressed air in the aftercooler 34A, and then the water cooler. Further heat recovery is performed from the added water at 25A. After that, the heat-recovered cooling water flows through the cooling water circulation line L9, is returned to the tank 62, and is sent back to the aftercooler 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 to the aftercooler 34A and the water cooler 25A again.
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 degassing treatment device 61 is circulated through the cooling water line L7 to recover heat from the compressed air in the aftercooler 34A, and then the water cooler. Further heat recovery is performed from the added water at 25A. After that, 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-added compressor system 1A and the heat recovery system 100A of the second embodiment described above, in addition to the above-mentioned effects (1) to (4), the following effects are exhibited.

(5) The water-added compressor system 1A is configured to include the pre-separator 8, and the aftercooler 34A is arranged on the second discharge line L312A for supplying compressed air from the pre-separator 8 to the separator tank 3, and the water cooler is provided. 25A was arranged on the third discharge line L313A that supplies water from the pre-separator 8 to the separator tank 3. As a result, even when the water-added compressor system 1A is configured to include the pre-separator 8, heat can be suitably recovered from the compressed air and the added water using the softened water produced by the hard water softening device 60.

(6) The water-added compressor system 1A was configured to include a cooling water circulation line L9. As a result, in response to the water supply request of the steam boiler 70 that uses the cooling water as the boiler water supply, the cooling water circulation mode that circulates the cooling water without supplying it to the steam boiler 70 and the steam boiler 70 that circulates the cooling water without circulating the cooling water. The cooling water non-circulation mode to be supplied can be switched. Therefore, it is possible to realize a water-added compressor system 1A and a heat recovery system 100A that can flexibly meet the water supply requirements of the steam boiler 70 (equipment to which cooling water is supplied).

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be appropriately modified.
For example, in the first embodiment and the second embodiment, the cooling water recovered by heat in the cooling water line L7 of the water-added compressor systems 1 and 1A is used as the boiler water supply of the steam boiler 70, but the present invention is not limited 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 of equipment other than the boiler.

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 softener 70 Steam boiler 100, 100A Heat recovery system L2 Water supply line L3, L3A Circulation line L7 Cooling water line L32 Return line L311A 1st discharge line L312A 2nd discharge line L313A 3rd discharge line

Claims (6)

With a water-added compressor
A separator tank that separates the compressed fluid discharged from the compressor into brackish water and
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 hard water softening device, which is arranged in the water supply line _{and produces softened water having a total hardness of 1 mgCaCO 3} / L or less, is provided.
A water-added compressor system in which neither a reverse osmosis membrane device nor an ion exchange device for producing pure water is arranged in the water supply line. After-cooler that recovers heat from compressed air,
A water cooler placed on the circulation line to recover heat from the added water,
The water-added compressor according to claim 1, further comprising a cooling water line whose upstream side is connected to the downstream side of the hard water softening device in the water supply line and supplies cooling water to the aftercooler and the water cooler. system. A pre-separator which is arranged between the compressor and the separator tank and performs pre-brackish water separation on the upstream side of the separator tank is further provided.
The circulation line
A first discharge line connecting the compressor and the pre-separator,
A second discharge line connecting the gas phase portion of the pre-separator and the gas phase portion of the separator tank,
A third discharge line connecting the liquid phase portion of the pre-separator and the liquid phase portion of the separator tank,
A return line for returning the added water stored in the separator tank to the compressor is provided.
The aftercooler is arranged in the second discharge line.
The water-added compressor system according to claim 2, wherein the water cooler is arranged in the third discharge line. The water-added compressor system according to any one of claims 1 to 3, wherein the hard water softening device produces softened water having an electric conductivity of 150 mS / m or less. The water-added compressor system according to any one of claims 1 to 4, wherein the hard water softening apparatus includes a Na-type cation exchange resin and softens water containing a hardness component with the Na-type cation exchange resin. .. The water-added compressor system according to claim 2 or 3.
A heat recovery system including a steam boiler connected to the downstream side of the cooling water line.

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