JP2013193013A - Seawater desalination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seawater desalination device capable of using natural energy or exhausted heat, reducing the energy consumption amount, and reducing the amount of injected chemicals.SOLUTION: A seawater desalination device includes a heat collector which heats a thermal medium by solar heat and a pretreatment membrane which removes a solid material from seawater to be desalinated, and cleaning water used for backward washing of the pretreatment membrane is made to be heated by the thermal medium heated by the heat collector.

Description

  Embodiments of the present invention relate to a seawater desalination apparatus that desalinates seawater.

  Seawater desalination apparatuses using reverse osmosis membranes are known. This seawater desalination apparatus conveys seawater with a seawater pump and causes it to flow into a pretreatment membrane. The pretreatment membrane is, for example, a hollow fiber membrane, and the seawater becomes pretreated seawater from which solid matter has been removed by filtration. The pre-treated seawater is increased in pressure by, for example, an osmotic pressure pump exceeding 6 MPa to become high-pressure seawater, and flows into the reverse osmosis membrane. The high pressure seawater is separated into fresh water that passes through the membrane and concentrated seawater that does not pass through the reverse osmosis membrane. In this way, fresh water for use in drinking water is obtained.

  When clogging occurs in the pretreatment membrane, washing water is poured from the direction opposite to the filtration direction to remove the solid matter collected in the pretreatment membrane (hereinafter referred to as “backwashing”). In such reverse cleaning, it is known that when the cleaning water is warm water, the deposited solid matter can be efficiently removed from the pretreatment film. In addition, if the clogging of the pretreatment film further increases, cleaning with chemicals is also performed. However, there is a known phenomenon that the time interval for performing cleaning with chemicals can be extended by backwashing the pretreatment film with warm water. It has been.

JP 52-27067 A Japanese Patent No. 4475925

  At present, there is a large amount of exhaust heat such as warm water, but the current situation is that they are not used and discarded to the atmosphere. For example, a generator-equipped gas engine, a generator-equipped gas turbine, and a fuel cell that are used as distributed power sources generate a large amount of hot water because they need cooling. However, the cooling tower radiates heat to the atmosphere and circulates it, or drains industrial water and tap water that have become hot water.

  In seawater desalination equipment, it is considered that these are used effectively. In the seawater desalination apparatus, if natural energy and exhaust heat can be used for seawater desalination, it is considered that the energy consumption of the seawater desalination apparatus can be reduced and the amount of chemical injection can be reduced.

  The problem to be solved by the present invention is to provide a seawater desalination apparatus that can utilize natural energy and exhaust heat, reduce energy consumption, and reduce chemical injection.

  In order to solve the problem, a seawater desalination apparatus according to an embodiment is configured as follows. The seawater desalination apparatus includes a heat collector that heats a heat medium by solar heat, and a pretreatment membrane that removes solid matter from seawater to be desalinated, and the washing water used for backwashing the pretreatment membrane is a collector It was decided that it could be heated with a heat medium heated at.

The block diagram which shows the whole seawater desalination apparatus concerning 1st Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 2nd Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 3rd Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 4th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 5th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 6th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 7th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 8th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 9th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 10th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 11th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning a 1st technique. The block diagram which shows the whole seawater desalination apparatus concerning a 2nd technique.

<First technology>
Prior to describing the seawater desalination apparatus of the embodiment, the first technique and the second technique which are the premise of each embodiment will be described with reference to FIGS. 12 and 13. The seawater desalination apparatus according to the first technique first transports the seawater 1 by the seawater pump 2 and causes it to flow into the pretreatment membrane 3. The pretreatment membrane 3 is, for example, a hollow fiber membrane, and the seawater 1 becomes pretreated seawater 4 from which solid substances have been removed by filtration. The pretreated seawater 4 is pressurized by, for example, an osmotic pressure pump 5 exceeding 6 MPa to become high-pressure seawater 6 and flows into the reverse osmosis membrane 7. The high pressure seawater 6 is separated by the reverse osmosis membrane 7 into fresh water 8 that passes through the membrane and concentrated seawater 9 that does not pass through. In this way, fresh water 8 for use in drinking water is obtained.

  The seawater desalination apparatus according to the first technique opens the on-off valves 10 and 11 and closes the on-off valves 17, 18 and 19 in normal operation. The backwash pump 15 is stopped and all other pumps are operated. The pretreated seawater 4 once enters the pretreated seawater tank 62 and is conveyed while being pressurized by the osmotic pressure pump 5 from there.

  Since the removed solid matter is deposited on the pretreatment membrane 3, the membrane is clogged and the seawater 1 becomes difficult to flow. Therefore, when the membrane differential pressure increases to some extent or when a certain amount of time elapses, the backwash operation is performed as follows.

  The seawater pump 2 is stopped and the on-off valves 10 and 11 are closed. Then, the on-off valves 17, 18, and 19 are opened, the backwash pump 15 is operated, and the wash water 16 from the pretreated seawater tank 62 is passed through the pretreatment membrane 3. Since the washing water 16 flows in the opposite direction to the seawater 1, the solid matter deposited on the membrane rides on the washing water 16 and is discharged to a washing drain tank (not shown). In this way, the pretreatment film 3 can be backwashed with a water flow.

  Even if the backwashing is repeated, the differential pressure of the pretreatment film 3 increases at a certain rate. Therefore, if the differential pressure sufficiently increases, cleaning using chemicals is also performed. The osmotic pressure pump 5 is also operated during the backwash operation, conveys the pretreated seawater 4 stored in the pretreated seawater tank 62 while increasing the pressure, and continues the desalination treatment.

<Second technology>
A seawater desalination apparatus as the second technique will be described with reference to FIG. Only parts different from the first technique will be described. In normal operation, the on-off valves 10 and 11 are opened, and the on-off valves 17, 18, 19, 64, and 65 are closed. The backwash pump 15 and the second backwash pump 67 are stopped and all other pumps are operated. The heater 66 is, for example, an electric heater and is not normally operated.

  The pretreated seawater 4 once enters the pretreated seawater tank 62 and is conveyed while being pressurized by the osmotic pressure pump 5. The fresh water 8 flows into the fresh water tank 12, from which an appropriate amount is taken out as the second fresh water 14 by the fresh water pump 13. Since the removed solid matter is deposited on the pretreatment membrane 3, the membrane is clogged and the seawater 1 becomes difficult to flow. Therefore, when the membrane differential pressure increases to some extent or when a certain amount of time elapses, the backwash operation is performed as follows.

  The seawater pump 2 is stopped and the on-off valves 10 and 11 are closed. Then, the on-off valves 17, 18, and 19 are opened, the backwash pump 15 is operated, and the wash water 16 from the pretreated seawater tank 62 is passed through the pretreatment membrane 3. Since the washing water 16 flows in the opposite direction to the seawater 1, the solid matter deposited on the membrane rides on the washing water 16 and is discharged to a washing drain tank (not shown). Now, some of the backwashing operations, for example, once every few times, are performed as follows.

  The seawater pump 2 is stopped, and the on-off valves 10, 11, 18, 19 are closed. Then, the on-off valves 17, 64, 65 are opened, the second backwash pump 67 is operated, the heater 66 is operated, and the second wash water 63 is heated. The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after the pretreatment is to prevent corrosion of the heater 66 due to seawater components. The cleaning water 16 may be heated by disposing it between the on-off valve 18 and the on-off valve 19.

  The second washing water 63 from the fresh water tank 12 is passed through the pretreatment film 3, but is hot water at the time when it flows into the pretreatment film 3. Since the second washing water 63 flows in the opposite direction to the seawater 1, the solid matter deposited on the membrane rides on the second washing water 63 and is discharged to a washing drain tank (not shown).

  In this way, the pretreatment film 3 can be backwashed with a water flow. Even if the backwashing is repeated, the differential pressure of the pretreatment film 3 increases at a certain rate. If the differential pressure sufficiently increases, cleaning with chemicals is also performed. Since the pretreatment film 3 has a large cleaning effect when it is backwashed with warm water, the use of the heated second cleaning water 63 extends the time for increasing the film differential pressure to a value that requires cleaning with chemicals. .

  Therefore, the time interval for performing the cleaning using the chemical is longer than that of the first technique, and the amount of chemical injection per day is reduced. Note that the osmotic pressure pump 5 is operated during the backwashing operation regardless of whether it is based on warm water, transports the pretreated seawater 4 stored in the pretreated seawater tank 62 while increasing the pressure, and performs the desalination treatment. continue. Thus, in the second technique, since the pretreatment film 3 is backwashed with warm water, the amount of chemical injection per day is reduced.

<First Embodiment>
The seawater desalination apparatus concerning 1st Embodiment is demonstrated using FIG. The first embodiment corresponds to claim 1. About the seawater desalination apparatus concerning 1st Embodiment, only a different part from the 1st, 2nd technique is demonstrated, and description is abbreviate | omitted about the same part.

  In the seawater desalination apparatus according to the first embodiment, when the sun rays 21 are sufficiently present and sufficient solar heat is obtained and the warm water washing is performed as the back washing operation of the pretreatment film 3, the following operation is performed. . The on-off valves 10, 11, 18, 19 are closed, the on-off valves 17, 64, 65 are opened, the seawater pump 2 and the backwash pump 15 are stopped, the water pump 24 and the second backwash pump 67 are operated, and the heater 66 is not activated. The water 25 is heated by the radiant heat of the solar rays 21 in the heat collector 26 and then flows into the washing water heater 40. The second washing water 63 is heated with water 25. The water 25 is circulated after the temperature is lowered by the washing water heater 40.

  When the pretreatment film 3 is back-washed with warm water, the cleaning effect is large. Therefore, by using the heated second cleaning water 63, the time during which the film differential pressure rises to a value that requires cleaning with a chemical is required. Extend. Compared with the second technology, the seawater desalination apparatus has a longer time interval for cleaning with chemicals, and the total amount of chemical injection when sufficient solar heat is obtained is reduced.

  Compared with the second technique, the energy consumption of the heater 66, for example, the power consumption of the electric heater is eliminated. The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after pretreatment is to prevent corrosion of the wash water heater 40 due to seawater components, The washing water heater 40 may be disposed between the on-off valve 18 and the on-off valve 19 to heat the washing water 16.

  Although hot water washing is performed as a backwash operation of the pretreatment film 3, when sufficient or no solar heat is obtained, sufficient solar rays 21 exist and sufficient solar heat is obtained, and the pretreatment film 3 is obtained. The water pump 24 is stopped and the heater 66 is operated from the state where the warm water cleaning is performed as the backwashing operation. The second cleaning water 63 simply passes through the cleaning water heater 40, and no problem occurs.

  When warm water cleaning is not performed as the back washing operation of the pretreatment film 3, warm water cleaning is performed as the back washing operation, but the solar valves are closed and opened from the state where sufficient or no solar heat is obtained. The valves 18 and 19 are opened, the second backwash pump 67 is stopped, the backwash pump 15 is operated, and the heater 66 is not operated. From the viewpoint of using solar heat, all the backwash operations may be hot water wash. However, in order to reduce the reduction of the total amount of the second fresh water 14 from the total amount of fresh water 8, some backwash operations are performed. Only driving.

  The seawater desalination apparatus performs normal backwash operation and does not cause any problems. The osmotic pressure pump 5 is operated during the backwash operation regardless of whether the water is hot or not, and is conveyed while increasing the pressure of the pretreated seawater 4 stored in the pretreated seawater tank 62. And continue desalination.

  When the backwash operation of the pretreatment film 3 is not performed, the operation is performed as follows. The on-off valves 10 and 11 are opened, the on-off valves 17, 18, 19, 64 and 65 are closed, the water pump 24, the backwash pump 15 and the second backwash pump 67 are stopped, the seawater pump 2 is operated, and the heater 66 is not activated. The seawater desalination apparatus performs normal operation and causes no problems.

  In the first embodiment, the backwash operation using hot water is possible when sufficient or no solar heat is obtained. However, the backwash operation using hot water is not possible without installing the heater 66. May be. The seawater desalination method need not be a method using a reverse osmosis membrane. By using natural energy, the time interval for cleaning with chemicals is extended, so that the total amount of chemical injection is reduced and energy consumption is reduced.

Second Embodiment
The seawater desalination apparatus concerning 2nd Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the second embodiment corresponds to claims 1 and 4. In the second embodiment, only parts different from the first embodiment will be described.

  When the sun rays 21 are sufficiently present and sufficient solar heat is obtained, and the warm water cleaning is not performed as the back cleaning operation of the pretreatment film 3, the following operation is performed. The on-off valves 10, 11, 18, 19 are closed, the on-off valves 17, 64, 65 are opened, the seawater pump 2 and the backwash pump 15 are stopped, the water pump 24 and the second backwash pump 67 are operated, and the heater 66 is not activated. After the water 25 is heated by the radiant heat of the solar rays 21 in the heat collector 26, it passes through the hot water tank type washing water heater 41. When the internal temperature of the hot water tank type washing water heater 41 that has been kept warm is sufficiently increased, the water pump 24 is stopped.

  When solar heat is sufficiently obtained and when warm water cleaning is performed as the backwash operation of the pretreatment film 3, the water pump 24 is operated and the backwash operation by warm water cleaning is performed as it is. When sufficient or no solar heat is obtained and when hot water cleaning is performed as a backwash operation, the water pump 24 is stopped, the heater 66 is not operated, and the others are the same.

  The second cleaning water 63 is heated when passing through the hot water tank type cleaning water heater 41, and the temperature inside the hot water tank type cleaning water heater 41 is lowered. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it.

  During normal operation or when performing backwash operation that is not hot water washing, not only the solar heat condition that is obtained, but the water pump 24 is stopped and the seawater desalination device is operated normally or backwash operation that is not hot water washing is performed. carry out. From the viewpoint of using solar heat, all the backwash operations may be hot water wash. However, in order to reduce the reduction of the total amount of the second fresh water 14 from the total amount of fresh water 8, some backwash operations are performed. Only driving.

  Note that heating the second wash water 63 from the fresh water tank 12 without heating the wash water 16 from the sea water tank 62 after pretreatment prevents corrosion of the hot water tank type wash water heater 41 due to sea water components. For this purpose, the hot water tank type washing water heater 41 may be disposed between the opening / closing valve 18 and the opening / closing valve 19 to heat the washing water 16. In the seawater desalination apparatus according to the second embodiment, the backwashing operation using the hot water heated by the heater 66 is possible. However, the heater 66 may not be installed. Further, the seawater desalination method need not be a method using a reverse osmosis membrane. Compared with the first embodiment, the presence of the hot water tank type washing water heater 41 sometimes produces an effect even when solar heat is not obtained sufficiently or not at all.

<Third Embodiment>
The seawater desalination apparatus concerning 3rd Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the third embodiment corresponds to claims 1 and 4. In the third embodiment, only parts different from the second embodiment will be described.

  When solar heat is sufficiently obtained, the water 25 flows through the heat storage tank type washing water heater 42 and heats the second heat storage material 43. The second heat storage material 43 is preferably a substance that utilizes a phase change between a liquid and a solid. When the temperature of the second heat storage material 43 is sufficiently increased, the water pump 24 is stopped.

  When sufficient or no solar heat is obtained, the water pump 24 is stopped and the backwash operation is performed as it is. When sufficient or no solar heat is obtained, and when hot water cleaning is performed as a backwash operation, the water pump 24 is stopped and the heater 66 is not operated, and the rest is the same. The second washing water 63 is heated when passing through the heat storage tank washing water heater 42. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it.

  During normal operation or when performing backwash operation that is not hot water washing, not only the solar heat condition that is obtained, but the water pump 24 is stopped and the seawater desalination device is operated normally or backwash operation that is not hot water washing is performed. carry out. From the viewpoint of using solar heat, all backwashing operations may be hot water washing, but in order to reduce the reduction of the total amount of the second freshwater 14 from the total amount of freshwater 8, some backwashing operations are performed. Only.

  Note that heating the second wash water 63 from the fresh water tank 12 without heating the wash water 16 from the sea water tank 62 after pretreatment prevents corrosion of the heat storage tank type wash water heater 42 due to sea water components. It is to do. The heat storage tank type washing water heater 42 may be disposed between the on-off valve 18 and the on-off valve 19 to heat the washing water 16.

  In the third embodiment, the back washing operation using hot water heated by the heater 66 is possible. However, the heater 66 may not be installed. Further, the seawater desalination method need not be a method using a reverse osmosis membrane. In addition to the effects of the second embodiment, the presence of the heat storage tank type washing water heater 42 as compared with the second embodiment makes it possible to perform the second washing for a longer time when solar heat cannot be obtained sufficiently or not at all. There is an effect that the water 63 is kept at a sufficient temperature.

<Fourth embodiment>
The seawater desalination apparatus concerning 4th Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the fourth embodiment corresponds to claims 1 and 5. In the fourth embodiment, only parts different from the second embodiment will be described.

  When solar heat is sufficiently obtained and when warm water cleaning is not performed as a backwash operation of the pretreatment film 3, the on-off valves 44, 27, 29, 45 are opened, the on-off valves 22, 23 are closed, and the water pump 24 is operated. Then, the second water pump 32 is stopped. At this time, the third water 31 does not flow.

  The water 25 heated by the heat collector 26 becomes the second water 30 and flows through the hot water tank 28. When the internal temperature of the hot water tank 28 that has been kept warm is sufficiently increased, the on-off valves 44, 27, 29, and 45 are closed.

  Regardless of the state of solar heat, when performing warm water cleaning as the backwash operation of the pretreatment film 3, the on-off valves 27, 29, 22, and 23 are opened, and the second water pump 32 is operated. The second water 30 having a sufficient temperature is taken out from the hot water tank 28 and flows into the washing water heater 40 as the third water 31 to heat and circulate the second washing water 63. The second washing water 63 is heated when passing through the heat storage tank washing water heater 42.

  When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it. When solar heat is sufficiently obtained and when hot water cleaning is performed as a backwash operation of the pretreatment film 3, the on-off valves 44, 45, 22, 23 are opened and the on-off valves 27, 29 are closed, The cleaning water 16 may be heated by causing the cleaning water heater 40 to circulate the entire amount or a part of the water 25 as the third water 31 by operating the water pump 24 at an intermediate opening.

  At this time, the second water pump 32 may or may not be operated. During normal operation or when performing backwash operation that is not hot water washing, the water pump 24 is stopped and the seawater desalination device is operated normally, or backwash operation that is not hot water washing is performed, not limited to the solar heat situation obtained. carry out.

  From the viewpoint of using solar heat, all the backwash operations may be hot water wash. However, in order to reduce the reduction of the total amount of the second fresh water 14 from the total amount of fresh water 8, some backwash operations are performed. Only driving.

  The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after pretreatment is to prevent corrosion of the wash water heater 40 due to seawater components, The washing water heater 40 may be disposed between the on-off valve 18 and the on-off valve 19 to heat the washing water 16.

  In the fourth embodiment, the back washing operation using the hot water heated by the heater 66 is possible, but the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane. The seawater desalination apparatus according to the fourth embodiment has the same effects as those of the second and third embodiments.

<Fifth Embodiment>
The seawater desalination apparatus concerning 5th Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the fifth embodiment corresponds to claims 1 and 6. In the fifth embodiment, only portions different from the third and fourth embodiments will be described.

  When solar heat is sufficiently obtained and the backwash operation of the pretreatment film 3 is not performed, the on-off valves 44, 27, 29, 45 are opened, the on-off valves 22, 23 are closed, the water pump 24 is operated, The water pump 32 is stopped. At this time, the third water 31 does not flow.

  The water 25 heated by the heat collector 26 becomes the second water 30, flows through the second heat storage tank 52, and heats the heat storage material 50. As the heat storage material 50, it is preferable to use a substance that utilizes a phase change between a liquid and a solid. When the temperature of the heat storage material 50 is sufficiently increased, the on-off valves 44, 27, 29, and 45 are closed.

  Regardless of the solar heat situation, when performing the backwash operation of the pretreatment film 3, the on-off valves 27, 29, 22, and 23 are opened, and the second water pump 32 is operated. Since the second water 30 is taken out while flowing through the second heat storage tank 52, the second water 30 has a sufficient temperature, flows into the washing water heater 40 as the third water 31, and heats the second washing water 63. Circulate. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it.

  When sufficient solar heat is obtained and when the backwash operation of the pretreatment film 3 is performed, the on-off valves 44, 45, 22, 23 are opened, and the on-off valves 27, 29 are closed, or the intermediate opening is set. By operating the water pump 24, the cleaning water 16 may be heated by circulating the entire amount or a part of the water 25 as the third water 31 to the cleaning water heater 40. At this time, the second water pump 32 may or may not be operated.

  During normal operation or when performing backwash operation that is not hot water washing, not only the solar heat condition that is obtained, but the water pump 24 is stopped and the seawater desalination device is operated normally or backwash operation that is not hot water washing is performed. carry out.

  From the viewpoint of using solar heat, all backwashing operations may be hot water washing, but in order to reduce the reduction of the total amount of the second freshwater 14 from the total amount of freshwater 8, some backwashing operations are performed. Only. The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after pretreatment is to prevent corrosion of the wash water heater 40 due to seawater components, The washing water heater 40 may be disposed between the opening / closing valve 18 and the opening / closing valve 19 to heat the washing water 16.

  In the fifth embodiment, the back washing operation using the hot water heated by the heater 66 is possible. However, the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane.

  The fifth embodiment has the same effects as the second, third, and fourth embodiments. Further, as compared with the fourth embodiment, the second cleaning water 63 is maintained at a sufficient temperature for a longer time when solar heat is not obtained sufficiently or not at all due to the presence of the second heat storage tank 52. There is an effect.

<Sixth Embodiment>
The seawater desalination apparatus concerning 6th Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the sixth embodiment corresponds to claim 2. In the sixth embodiment, only parts different from the first technique and the first embodiment will be described.

  The distributed power source 36 is, for example, a gas engine with a generator, a gas turbine with a generator, a fuel cell, and the like, and the exhaust heat is sufficiently large and is radiated from the exhaust heat heat exchanger 35 to the water 25. When waste heat is used for seawater desalination in the sixth embodiment, the seawater desalination device performs warm water cleaning as a backwash operation of the pretreatment membrane 3, and when not used, the seawater desalination device operates normally. Or carry out backwash operation without using hot water.

  When the exhaust heat is not used for seawater desalination, the on-off valves 27 and 29 are opened, the on-off valves 22 and 23 are closed, the third water 31 is not allowed to flow, and the water pump 24 is operated. The second water 30 flows into the cooling tower 33, is cooled by the atmosphere 34, and circulates. The atmosphere 34 may or may not be forced.

  When exhaust heat is used for seawater desalination, the on-off valves 27 and 29 are closed, the second water 30 is not flowed, and the on-off valves 22 and 23 are opened. The third water 31 flows into the washing water heater 40 and heats the second washing water 63. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it. When the pretreatment film 3 is back-washed with warm water, the cleaning effect is large. Therefore, by using the heated second cleaning water 63, the time during which the film differential pressure rises to a value that requires cleaning with a chemical is required. Extend.

  Compared with the first technology, the seawater desalination apparatus according to the sixth embodiment extends the time interval for cleaning with chemicals and reduces the total amount of chemical injection when exhaust heat is obtained. Compared with the second technique, the energy consumption of the heater 66, for example, the power consumption of the electric heater is eliminated. However, since the membrane blocking rate may decrease due to a rise in water temperature and the quality of treated water may deteriorate, the larger the water temperature rise is, the better, not the better the water temperature rise.

  Therefore, when the temperature drop of the third water 31 by the washing water heater 40 is not sufficient, the on-off valves 27 and 29 are fully opened or the intermediate opening degree is passed, and the second water 30 is circulated to the cooling tower 33 to exhaust heat. The temperature of the water 25 returning to the heat exchanger 35 is sufficiently lowered.

  During normal operation or when performing a backwash operation that is not warm water cleaning, the water pump 24 is stopped and the seawater desalination apparatus is operated normally, or a backwash operation that is not warm water cleaning is performed. From the viewpoint of using exhaust heat, all backwashing operations may be hot water washing, but in order to reduce the reduction amount of the total amount of the second freshwater 14 from the total amount of freshwater 8, some backwashing operations are performed. Only driving.

  The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after pretreatment is to prevent corrosion of the wash water heater 40 due to seawater components. Yes, the cleaning water heater 40 may be disposed between the on-off valve 18 and the on-off valve 19 to heat the cleaning water 16.

  In the sixth embodiment, the backwash operation using the hot water heated by the heater 66 is possible, but the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane.

  In the seawater desalination apparatus according to the sixth embodiment, by using the exhaust heat of the distributed power source 36, the cleaning time interval using the chemical is extended, the total amount of chemical injection is reduced, and the energy consumption is reduced. . Note that the combustion exhaust gas discharged from the distributed power source 36 to the atmosphere may be at a temperature enough to heat the pretreated seawater 4 to 25 ° C. even after cooling. In this case, heat is recovered from the combustion exhaust gas, and the water 25 May be heated.

  Gas engines and gas turbines are often used as a distributed power source 36 by connecting a generator. However, there is a mode in which shaft power is taken out but power generation is not performed. Even in this case, the exhaust heat of the gas engine and gas turbine is sufficient. The same effect can be obtained by applying the same configuration.

<Seventh embodiment>
The seawater desalination apparatus concerning 7th Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the seventh embodiment corresponds to claims 2 and 4. In the seventh embodiment, only parts different from the sixth embodiment will be described.

  The exhaust heat from the distributed power source 36 is radiated from the exhaust heat exchanger 35 to the water 25. When waste heat is used for seawater desalination in the seventh embodiment, the seawater desalination apparatus performs warm water cleaning as a backwash operation of the pretreatment membrane 3, and when not used, the seawater desalination apparatus operates normally. Alternatively, backwash operation that does not rely on hot water is performed.

  When the exhaust heat is not used for seawater desalination, the on-off valves 27, 29, 22, and 23 are opened, the water pump 24 is operated, and the second water 30 and the third water 31 are allowed to flow. The second water 30 flows into the cooling tower 33, is cooled by the atmosphere 34, and circulates. The atmosphere 34 may or may not be forced.

  When the temperature of the water 25 flowing into the exhaust heat exchanger 35 is not sufficiently lowered, the flow rate ratio at which the on-off valves 22 and 23 are fully closed or set to an intermediate opening and the second water 30 is circulated to the cooling tower 33 is set. Increase the temperature sufficiently. When the internal temperature of the hot water tank type washing water heater 41 that has been kept warm is sufficiently increased by the third water 31, the on-off valves 22 and 23 are closed.

  When the distributed power source 36 is not in operation and waste heat is used for seawater desalination, the seawater desalination apparatus performs the backwash operation while the on-off valves 22 and 23 are closed. The second cleaning water 63 is heated by the third water 31 stored while keeping the temperature inside the warm water tank type cleaning water heater 41. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it. The internal temperature of the hot water tank type washing water heater 41 decreases.

  Since the pretreatment film 3 has a large cleaning effect when backwashed with warm water, the time for the film differential pressure to rise to a value that requires cleaning with a chemical by using the heated second cleaning water 63. Extend. Compared to the first technology, the seawater desalination apparatus has a longer time interval for cleaning with chemicals, and the total amount of chemical injection when exhaust heat is obtained is reduced. Compared with the second technique, the energy consumption of the heater 66, for example, the power consumption of the electric heater is eliminated. However, since the membrane blocking rate may decrease due to a rise in water temperature and the quality of treated water may deteriorate, the larger the water temperature rise, the better. The rise in water temperature is an appropriate amount.

  When the distributed power source 36 is in operation and waste heat is used for seawater desalination, the on-off valves 22 and 23 are fully opened, the water pump 24 is operated, and the seawater desalination device is backwashed with warm water. To do. When the temperature of the water 25 flowing into the exhaust heat exchanger 35 is not sufficiently lowered, the on-off valves 27 and 29 are fully opened or set to an intermediate opening degree, and the second water 30 is circulated through the cooling tower 33 to obtain a sufficient temperature. Reduce.

  From the viewpoint of using exhaust heat, all backwashing operations may be hot water washing, but in order to reduce the reduction amount of the total amount of the second freshwater 14 from the total amount of freshwater 8, some backwashing operations are performed. Only driving. The reason for heating the second wash water 63 from the fresh water tank 12 without heating the wash water 16 from the sea water tank 62 after pretreatment is to prevent corrosion of the hot water tank type wash water heater 41 due to sea water components. The hot water tank type washing water heater 41 may be disposed between the opening / closing valve 18 and the opening / closing valve 19 to heat the washing water 16.

  In the seventh embodiment, the back washing operation using the hot water heated by the heater 66 is possible. However, the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane.

  The seawater desalination apparatus according to the seventh embodiment has the effect of the sixth embodiment. Furthermore, compared to the sixth embodiment, the time when the effect occurs even when the exhaust heat is not obtained sufficiently or not at all. is there. A gas engine and a gas turbine are often used as a distributed power source 36 by connecting a generator. However, there is a mode in which shaft power is taken out but power generation is not performed. In this case as well, the exhaust heat of the gas engine and gas turbine is It is sufficiently large and effective by applying the same configuration.

<Eighth Embodiment>
The seawater desalination apparatus concerning 8th Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the eighth embodiment corresponds to claims 2 and 4 as in the seventh embodiment. In the eighth embodiment, only parts different from the seventh embodiment will be described.

  The exhaust heat from the distributed power source 36 is radiated from the exhaust heat exchanger 35 to the water 25. When waste heat is used for seawater desalination in the eighth embodiment, the seawater desalination device performs warm water cleaning as a backwash operation of the pretreatment membrane 3, and when not used, the seawater desalination device operates normally. Alternatively, backwash operation that does not rely on hot water is performed. When the exhaust heat is not used for seawater desalination, the on-off valves 27, 29, 22, 23 are opened, the water pump 24 is operated, and the second water 30 and the third water 31 are allowed to flow.

  The second water 30 flows into the cooling tower 33, is cooled by the atmosphere 34, and circulates. The atmosphere 34 may or may not be forced. When the temperature of the water 25 flowing into the exhaust heat exchanger 35 is not sufficiently lowered, the flow rate ratio at which the on-off valves 22 and 23 are fully closed or set to an intermediate opening and the second water 30 is circulated to the cooling tower 33 is set. Increase the temperature sufficiently.

  The third water 31 circulates through the heat storage tank type washing water heater 42 and heats the second heat storage material 43. The second heat storage material 43 is preferably a substance that utilizes a phase change between a liquid and a solid. When the temperature of the second heat storage material 43 is sufficiently increased, the on-off valves 22 and 23 are closed.

  When the distributed power source 36 is not operating and the exhaust heat is used for seawater desalination, the seawater desalination apparatus performs the backwash operation while the on-off valves 22 and 23 are closed. The second washing water 63 is heated when passing through the heat storage tank washing water heater 42. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it. The internal temperature of the hot water tank type washing water heater 41 decreases.

  Since the pretreatment film 3 has a large cleaning effect when backwashed with warm water, the time for the film differential pressure to rise to a value that requires cleaning with a chemical by using the heated second cleaning water 63. Extend. Compared to the first technology, the seawater desalination apparatus has a longer time interval for cleaning with chemicals, and the total amount of chemical injection when exhaust heat is obtained is reduced. Compared with the second technique, the energy consumption of the heater 66, for example, the power consumption of the electric heater is eliminated. However, since the membrane blocking rate may decrease due to a rise in water temperature and the quality of treated water may deteriorate, the larger the water temperature rise, the better. The rise in water temperature is an appropriate amount.

  When the distributed power source 36 is in operation and the waste heat is used for seawater desalination, the on-off valves 22 and 23 are fully opened and the water pump 24 is operated, and the seawater desalination apparatus performs backwash operation using hot water. carry out. When the temperature of the water 25 flowing into the exhaust heat exchanger 35 is not sufficiently lowered, the on-off valves 27 and 29 are fully opened or set to an intermediate opening degree, and the second water 30 is circulated through the cooling tower 33 to obtain a sufficient temperature. Reduce.

  From the viewpoint of using exhaust heat, all backwashing operations may be hot water washing, but in order to reduce the reduction amount of the total amount of the second freshwater 14 from the total amount of freshwater 8, some backwashing operations are performed. Only driving. The reason for heating the second wash water 63 from the fresh water tank 12 without heating the wash water 16 from the sea water tank 62 after pretreatment is to prevent corrosion of the heat storage tank type wash water heater 42 due to sea water components. The heat storage tank type washing water heater 42 may be disposed between the opening / closing valve 18 and the opening / closing valve 19 to heat the washing water 16. In the eighth embodiment, the back washing operation using the hot water heated by the heater 66 is possible. However, the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane.

  The seawater desalination apparatus according to the eighth embodiment maintains the temperature of the second washing water 63 at a sufficient temperature for a longer period of time compared to the seventh embodiment when sufficient or no exhaust heat is obtained. There is a dripping effect. A gas engine and a gas turbine are often used as a distributed power source 36 by connecting a generator. However, there is a mode in which shaft power is taken out but power generation is not performed. In this case as well, the exhaust heat of the gas engine and gas turbine is It is sufficiently large and effective by applying the same configuration.

<Ninth Embodiment>
The seawater desalination apparatus concerning 9th Embodiment is demonstrated using FIG. The seawater desalination apparatus according to the ninth embodiment corresponds to claims 2 and 7. In the ninth embodiment, only parts different from the eighth embodiment will be described.

  The exhaust heat from the distributed power source 36 is radiated from the exhaust heat exchanger 35 to the water 25. When exhaust heat is used for seawater desalination in the ninth embodiment, the seawater desalination apparatus performs warm water cleaning as a backwash operation of the pretreatment membrane 3, and when not used, the seawater desalination apparatus operates normally. Or carry out backwash operation without using hot water.

  When exhaust heat is not used for seawater desalination, the on-off valves 27, 29, 46, 47, 60, 61 are opened, the on-off valves 22, 23 are closed, the water pump 24 is operated, and the second water pump 32 is stopped. Then, the second water 30 and the third water 31 are poured. The second water 30 flows into the cooling tower 33, is cooled by the atmosphere 34, and circulates. The atmosphere 34 may or may not be forced.

  When the temperature drop of the water 25 flowing into the exhaust heat exchanger 35 is not sufficient, the flow rate ratio at which the on-off valves 46 and 47 are fully closed or set to an intermediate opening and the second water 30 is circulated to the cooling tower 33 is set. Increase the temperature sufficiently. The third water 31 flows through the hot water tank 28. When the internal temperature of the hot water tank 28 that is kept warm is sufficiently increased, the on-off valves 22 and 23 are closed.

  When the distributed power source 36 is not operating and waste heat is used for seawater desalination, the on-off valves 60, 61 are closed, the on-off valves 22, 23, 46, 47 are opened, and the second water pump 32 is turned on. In operation, the seawater desalination unit performs backwashing operation using warm water. The second water 30 having a sufficient temperature is taken out from the hot water tank 28 and becomes the fourth water 48. The fourth water 48 heats the second cleaning water 63 by the cleaning water heater 40. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it. The internal temperature of the hot water tank type washing water heater 41 decreases.

  Since the pretreatment film 3 has a large cleaning effect when backwashed with warm water, the time for the film differential pressure to rise to a value that requires cleaning with a chemical by using the heated second cleaning water 63. Extend. Compared with the first technology, the seawater desalination apparatus according to the ninth embodiment extends the time interval for cleaning with chemicals and reduces the total amount of chemical injection when exhaust heat is obtained. Compared with the second technique, the energy consumption of the heater 66, for example, the power consumption of the electric heater is eliminated. However, since the membrane blocking rate may decrease due to an increase in the water temperature and the quality of the treated water may deteriorate, the larger the increase in the water temperature, the better. Raise.

  When the distributed power source 36 is operating and waste heat is used for seawater desalination, the on-off valves 22 and 23 are fully opened and the water pump 24 is operated. The seawater desalination apparatus is backwashed using warm water. To implement. The second water pump 32 may or may not be operated. However, if the second water pump 32 is not configured to allow fluid to pass from upstream to downstream of the second water pump 32 with the second water pump 32 stopped, the second water pump 32 is Let's drive. If the temperature of the water 25 flowing into the exhaust heat exchanger 35 is not sufficiently lowered, the on-off valves 46 and 47 are fully opened or set to an intermediate opening, and the flow rate of the second water 30 flowing through the cooling tower 33 is increased. Reduce the temperature sufficiently.

  From the viewpoint of using exhaust heat, all backwashing operations may be hot water washing, but in order to reduce the reduction amount of the total amount of the second freshwater 14 from the total amount of freshwater 8, some backwashing operations are performed. Only driving. The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after pretreatment is to prevent corrosion of the wash water heater 40 due to seawater components. The washing water heater 40 may be disposed between the opening / closing valve 18 and the opening / closing valve 19 to heat the washing water 16.

  In the ninth embodiment, the back washing operation using the hot water heated by the heater 66 is possible. However, the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane.

  The seawater desalination apparatus according to the ninth embodiment has the same effects as those of the seventh embodiment. Gas engines and gas turbines are often used as a distributed power source 36 by connecting a generator. However, there is a mode in which shaft power is taken out but power generation is not performed. Even in this case, the exhaust heat of the gas engine and gas turbine is sufficient. The same effect can be obtained by applying the same configuration.

<Tenth Embodiment>
A seawater desalination apparatus according to a tenth embodiment will be described with reference to FIG. The seawater desalination apparatus according to the tenth embodiment corresponds to claims 2 and 8. In the tenth embodiment, only parts different from the eighth and ninth embodiments will be described.

  The exhaust heat from the distributed power source 36 is radiated from the exhaust heat exchanger 35 to the water 25. When waste heat is used for seawater desalination in the tenth embodiment, the seawater desalination device performs warm water cleaning as a backwash operation of the pretreatment membrane 3, and when not used, the seawater desalination device operates normally. Or carry out backwash operation without using hot water.

  When the exhaust heat is not used for seawater desalination, the on-off valves 27, 29, 46, 47, 60, 61 are opened, the on-off valves 22, 23 are closed, the water pump 24 is operated, and the second water pump 32 is Stop and pour the second water 30 and the third water 31. The second water 30 flows into the cooling tower 33, is cooled by the atmosphere 34, and circulates. The atmosphere 34 may or may not be forced. When the temperature drop of the water 25 flowing into the exhaust heat exchanger 35 is not sufficient, the flow rate ratio at which the on-off valves 46 and 47 are fully closed or set to an intermediate opening and the second water 30 is circulated to the cooling tower 33 is set. Increase the temperature sufficiently.

  The third water 31 circulates through the heat storage tank type washing water heater 42 and heats the second heat storage material 43. The second heat storage material 43 is preferably a substance that utilizes a phase change between a liquid and a solid. When the temperature of the second heat storage material 43 is sufficiently increased, the on-off valves 22 and 23 are closed.

  When the distributed power source 36 is not operating and waste heat is used for seawater desalination, the on-off valves 60, 61 are closed, the on-off valves 22, 23, 46, 47 are opened, and the second water pump 32 is turned on. In operation, the seawater desalination apparatus performs a backwash operation using warm water. When the third water 31 passes through the second heat storage tank 52, it is heated by the heat storage material 50 and becomes the fourth water 48. The fourth water 48 heats the second cleaning water 63 by the cleaning water heater 40. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it. The internal temperature of the hot water tank type washing water heater 41 decreases.

  Since the pretreatment film 3 has a large cleaning effect when it is backwashed with warm water, the use of the heated second cleaning water 63 extends the time for increasing the film differential pressure to a value that requires cleaning with chemicals. . The seawater desalination apparatus according to the tenth embodiment has a longer time interval for cleaning with chemicals than the first technology, and the total amount of chemical injection when exhaust heat is obtained is reduced. Compared with the second technique, the energy consumption of the heater 66, for example, the power consumption of the electric heater is eliminated. However, since the membrane blocking rate may decrease due to an increase in the water temperature and the quality of the treated water may deteriorate, the larger the increase in the water temperature, the better. Raise.

  When the distributed power source 36 is operating and waste heat is used for seawater desalination, the on-off valves 22 and 23 are fully opened and the water pump 24 is operated. The seawater desalination apparatus is backwashed using warm water. To implement. The second water pump 32 may or may not be operated. However, if the second water pump 32 is not configured to allow fluid to pass from upstream to downstream of the second water pump 32 with the second water pump 32 stopped, the second water pump 32 is Let's drive. If the temperature of the water 25 flowing into the exhaust heat exchanger 35 is not sufficiently lowered, the on-off valves 46 and 47 are fully opened or set to an intermediate opening, and the flow rate of the second water 30 flowing through the cooling tower 33 is increased. Reduce the temperature sufficiently.

  From the viewpoint of using exhaust heat, all the backwash operations may be hot water washing, but in order to reduce the amount of reduction of the total amount of the second fresh water 14 from the total amount of fresh water 8, some reverse washing operations are performed. Only washing operation. The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after pretreatment is to prevent corrosion of the wash water heater 40 due to seawater components, The washing water heater 40 may be disposed between the opening / closing valve 18 and the opening / closing valve 19 to heat the washing water 16.

  In the tenth embodiment, the back washing operation using the hot water heated by the heater 66 is possible. However, the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane.

  The seawater desalination apparatus according to the tenth embodiment has the same effect as that of the ninth embodiment, and when exhaust heat is not obtained sufficiently or not at all, compared to the ninth embodiment, There is an effect that the second washing water 63 is kept at a sufficient temperature. Gas engines and gas turbines are often used as a distributed power source 36 by connecting a generator. However, there is a mode in which shaft power is taken out but power generation is not performed. Even in this case, the exhaust heat of the gas engine and gas turbine is sufficient. The same effect can be obtained by applying the same configuration.

<Eleventh embodiment>
A seawater desalination apparatus according to an eleventh embodiment will be described. The seawater desalination apparatus according to the eleventh embodiment corresponds to claim 2 as in the sixth to tenth embodiments. In the sixth to tenth embodiments, the exhaust heat of the distributed power source 36 is recovered from the exhaust heat exchanger 35. On the other hand, the seawater desalination apparatus according to the eleventh embodiment is an air conditioner 54 such as a building. When the cooling operation is performed (see FIGS. 6 to 10), exhaust heat that is finally thrown away into the atmosphere is recovered directly or through water from the condenser 55 corresponding to the outdoor unit.

  Since there are buildings that require cooling for humans and machines to manage the seawater desalination apparatus, the air conditioner 54 may be installed near the seawater desalination apparatus. In the seawater desalination apparatus according to the eleventh embodiment, the distributed power source 36 and the exhaust heat exchanger 35 in the sixth to tenth embodiments are replaced with an air conditioner 54 and a condenser 55, respectively.

  By using the exhaust heat of the air conditioner 54, power consumption can be reduced. Similar to the cooling operation of air conditioners 54 such as buildings, the condensers of refrigerators such as chilled water chillers and cold chains also dissipate the exhaust heat directly or through water, and finally recover this. The same effect can be obtained by applying the same configuration so that it can be used.

<Twelfth embodiment>
A seawater desalination apparatus according to the twelfth embodiment will be described. The seawater desalination apparatus according to the twelfth embodiment corresponds to claim 2 as in the sixth to eleventh embodiments. In the sixth to tenth embodiments, the exhaust heat of the distributed power source 36 is recovered from the exhaust heat exchanger 35. On the other hand, the exhaust heat from the water-cooled computer 57 (see FIGS. 6 to 10) is recovered. . Since a large-scale computer is used for monitoring and controlling the seawater desalination equipment, the water-cooled computer 57 may be installed near the seawater desalination equipment, and the exhaust heat is directly or directly via water. It is thrown away to the atmosphere. In the seawater desalination apparatus according to the twelfth embodiment, the distributed power source 36 in the sixth to tenth embodiments is replaced with a water-cooled computer 57. By using the exhaust heat of the water-cooled computer 57, the power consumption may be reduced.

<13th Embodiment>
A seawater desalination apparatus according to a thirteenth embodiment will be described with reference to FIG. The seawater desalination apparatus according to the thirteenth embodiment corresponds to claim 3. In the thirteenth embodiment, only parts different from the second technique will be described. Steam turbine plants often use seawater for condensers, and are often installed near the sea, similar to seawater desalination equipment. There is a system that separates and recovers carbon dioxide from boiler exhaust gas in a steam turbine plant, and extracted steam from the steam turbine may be used as a necessary heat source in the process.

  After heating with the extracted steam, the extracted steam drops in temperature and is discarded in the condenser. At this time, some or all of the extracted steam may be condensed. The water 25 is heated by the heat of the extracted steam after this temperature drop. Further, the extracted steam whose temperature has dropped is discarded in the condenser. In FIG. 11, the heat medium 37 after heat recovery by the carbon dioxide separation and recovery system 39 flows out and flows into the heat recovery unit 38. The heat medium 37 is extracted steam or a liquid heated by the extracted steam.

  When waste heat is used for seawater desalination in the thirteenth embodiment, the seawater desalination device performs warm water cleaning as a backwash operation of the pretreatment membrane 3, and when not used, the seawater desalination device operates normally or Perform backwash operation without using hot water. When waste heat is used for seawater desalination, the on-off valves 22, 23, 59 are opened, the on-off valve 58 is closed, the water pump 24 is operated, and the seawater desalination apparatus performs a backwash operation using hot water. .

  The heat medium 37 flows through the heat recovery unit 38 and heats the water 25. The temperature of the heat medium 37 is lowered by the heat recovery unit 38 and then returned to the carbon dioxide separation and recovery system 39. The water 25 heats the second cleaning water 63 by the cleaning water heater 40. When the temperature of the second washing water 63 is not sufficient, the heater 66 is operated to heat it.

  Since the pretreatment film 3 has a large cleaning effect when backwashed with warm water, the time for the film differential pressure to rise to a value that requires cleaning with a chemical by using the heated second cleaning water 63. Extend. The seawater desalination apparatus according to the thirteenth embodiment has a longer time interval for cleaning with chemicals than the first technique, and the total amount of chemical injection when exhaust heat is obtained is reduced. Compared with the second technique, the energy consumption of the heater 66, for example, the power consumption of the electric heater is eliminated. However, since the membrane blocking rate may decrease due to an increase in the water temperature and the quality of the treated water may deteriorate, the larger the increase in the water temperature, the better. The appropriate amount and the water temperature should be adjusted by adjusting the opening of the on-off valve 22, for example. Raise.

  In the seawater desalination apparatus according to the thirteenth embodiment, by using the exhaust heat of the carbon dioxide separation and recovery system 39, the time interval for cleaning with chemicals is extended and the total amount of chemical injection at night is reduced. When the exhaust heat is not used for seawater desalination, the on-off valve 58 is opened, the on-off valves 22, 23, 59 are closed, and the water pump 24 is stopped. The heat medium 37 returns to the carbon dioxide separation and recovery system 39 without flowing through the heat recovery device 38, and there is no problem.

  From the viewpoint of using exhaust heat, all the backwash operations may be hot water washing, but in order to reduce the amount of reduction of the total amount of the second fresh water 14 from the total amount of fresh water 8, some reverse washing operations are performed. Only washing operation. The reason for heating the second wash water 63 from the freshwater water tank 12 without heating the wash water 16 from the seawater tank 62 after pretreatment is to prevent corrosion of the wash water heater 40 due to seawater components, The washing water heater 40 may be disposed between the opening / closing valve 18 and the opening / closing valve 19 to heat the washing water 16.

  In the thirteenth embodiment, the back washing operation using the hot water heated by the heater 66 is possible, but the heater 66 may not be installed. The seawater desalination method need not be a method using a reverse osmosis membrane.

  Note that the on-off valves 58 and 59 and the heat medium 37 do not have to bypass the heat recovery unit 38. In the case of a configuration without a bypass pipe, the heat medium 37 circulates through the heat recovery unit 38 even when the exhaust heat is not used in the seawater desalination apparatus. Since it returns, it is the same as when there is a bypass pipe, and there is no problem.

  As described above, according to the present embodiment, it is possible to use natural energy and exhaust heat, thereby providing a seawater desalination apparatus that can reduce energy consumption and chemical injection amount. it can. In the embodiment, the pretreatment membrane 3 and the reverse osmosis membrane 7 are provided. However, these include a pretreatment membrane or a reverse osmosis membrane inside, and the inside is defined by these, and the filtration performance and osmotic pressure by these membranes are provided. It refers to equipment that uses the action of. In addition, the present embodiment may be provided with a control device and operated according to an instruction from the control device.

  In addition, this invention is not limited to the said embodiment, These embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Seawater, 2 ... Seawater pump, 3 ... Pretreatment membrane, 4 ... Pretreatment seawater, 5 ... Osmotic pressure pump, 6 ... High pressure seawater, 7 ... Reverse osmosis membrane, 8 ... Fresh water, 9 ... Concentrated seawater, 10, DESCRIPTION OF SYMBOLS 11 ... Open / close valve, 12 ... Fresh water tank, 13 ... Fresh water pump, 14 ... Second fresh water, 15 ... Backwash pump, 16 ... Wash water, 17, 18, 19 ... Open / close valve, 21 ... Sunlight, 22, 23 Open / close valve, 24 ... water pump, 25 ... water, 26 ... collector, 27, 29 ... open / close valve, 28 ... hot water tank, 30 ... second water, 31 ... third water, 32 ... second Water pump 33 ... cooling tower 34 ... air 35 ... exhaust heat exchanger 36 ... distributed power source 37 ... heat medium 38 ... heat recovery unit 39 ... carbon dioxide separation and recovery system 40 ... washing water heater , 41 ... warm water tank type washing water heater, 42 ... heat storage tank type washing water heater, 43 ... second heat storage material, 44, 45, 4 47 ... Open / close valve, 48 ... Fourth water, 50 ... Thermal storage material, 52 ... Second thermal storage tank, 54 ... Air conditioner, 55 ... Condenser, 57 ... Water-cooled calculator, 58, 60, 61 ... Open / close valve, 62 ... Seawater tank after pretreatment, 63 ... Second wash water, 64, 65 ... Open / close valve, 66 ... Heater, 67 ... Second backwash pump.

Claims (8)

A seawater desalination device for desalinating seawater,
A collector that heats the heat medium by solar heat;
A pretreatment membrane for removing solid matter from the seawater to be desalinated,
A seawater desalination apparatus characterized in that all or part of the washing water used for backwashing the pretreatment membrane can be heated by the heat medium heated by the heat collector. A seawater desalination device for desalinating seawater,
A heat exchanger that heats the heat medium by exhaust heat from any of a distributed power source, a gas engine, a gas turbine, a fuel cell, a computer, a refrigerator, or a cooling air conditioner;
A pretreatment membrane for removing solid matter from the seawater to be desalinated,
A seawater desalination apparatus, wherein all or part of the washing water used for backwashing the pretreatment membrane can be heated by the heat medium heated by the heat exchanger. A seawater desalination device for desalinating seawater,
A heat exchanger that heats a heat medium with extracted steam from a steam turbine used as a heating source in a carbon dioxide separation and recovery system;
A pretreatment membrane for removing solid matter from the seawater to be desalinated,
A seawater desalination apparatus, wherein all or part of the washing water used for backwashing the pretreatment membrane can be heated by the heat medium heated by the heat exchanger. The heater for heating the washing water has a structure that doubles as a tank that stores the heat medium or a tank that stores a heat storage material,
The seawater desalination apparatus according to any one of claims 1 to 3, wherein all or part of the washing water can be heated by heat stored in the heat medium or the heat storage material in the heater. A circulation flow path in which the heat medium heated by the heat collector returns to the heat collector without flowing into the wash water heater that heats the wash water;
A tank for storing the heat medium provided in the circulation flow path;
The seawater desalination apparatus according to claim 1, wherein the heat medium stored in the tank can be caused to flow into the washing water heater by switching the flow path. A circulation flow path in which the heat medium heated by the heat collector returns to the heat collector without flowing into the wash water heater that heats the wash water;
A tank for storing the heat storage material provided in the circulation channel;
2. The seawater desalination apparatus according to claim 1, wherein the heat medium can be heated by heat stored in the heat storage material by flow path switching, and the heat medium can flow into the washing water heater. . A circulation flow path in which the heat medium heated in the heat exchanger returns to the heat exchanger without flowing into the washing water heater for heating the washing water;
A tank for storing the heat medium provided in the circulation flow path;
The seawater desalination apparatus according to claim 2 or 3, wherein the heat medium stored in the tank can be caused to flow into the washing water heater by switching the flow path. A circulation flow path in which the heat medium heated in the heat exchanger returns to the heat exchanger without flowing into the washing water heater for heating the washing water;
A tank for storing the heat storage material provided in the circulation channel;
The seawater freshwater according to claim 2 or 3, wherein the heat medium can be heated by heat stored in the heat storage material by flow path switching, and the heat medium can be caused to flow into the washing water heater. Device.

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