JP7647813B2 - Warm ultrapure water production equipment - Google Patents

Description

The present invention relates to a hot ultrapure water production device, and more specifically, to a hot ultrapure water production device configured to heat ultrapure water from a subsystem using a heat exchanger and supply it to a use point as hot ultrapure water.

The ultrapure water used for semiconductor cleaning is produced in an ultrapure water production system that consists of a primary pure water production system and a subsystem (secondary pure water production system).

In the subsystem, the TOC is decomposed into organic acids and even _CO2 using ultraviolet light emitted from a low-pressure ultraviolet lamp. The organic matter and _CO2 produced by the decomposition are removed by an ion exchange device, and fine particles are removed by an ultrafiltration membrane separation device, leaving ultrapure water.

This ultrapure water may be heated in a heat exchanger to produce hot ultrapure water, which is then sent to a point of use. Heated water heated by a heat pump may be used as the heat source fluid for this heat exchanger (Patent Document 1).

Figure 4 is a system diagram showing an example of a hot ultrapure water production system with a conventional heat pump type heating device.

The primary pure water passes from sub-tank 1 through cooler 2, where it is cooled to approximately 23°C, before being introduced into subsystem 4 via pipe 3 to produce ultrapure water. The ultrapure water produced at approximately 25°C flows in this order through pipe 5, first heat exchanger 6, pipe 9 and second heat exchanger 10, where it is heated to approximately 45-70°C by first heat exchanger 6, and to approximately 75°C by second heat exchanger 10, before being sent as warm ultrapure water to the point of use via pipe 11. A UF membrane device 12 is installed in pipe 11.

Return-temperature ultrapure water of about 70°C from the point of use is introduced via piping 7 into the heat source fluid flow path of the first heat exchanger 6. This return-temperature ultrapure water is cooled by heat exchange with ultrapure water from the subsystem 4 in the heat exchanger 6, and then sent to the subtank 1 via piping 8.

The first water medium (water as a heat transfer medium) heated by the heat pump 20 and the steam heater 15 circulates through the heat source fluid flow path of the second heat exchanger 10. That is, the first water medium that has passed through the heat source fluid flow path of the heat exchanger 10 is passed from the pipe 13 to the condenser 23 of the heat pump 20 to be heated, and then passed from the pipe 14 to the steam heater 15 to be further heated. The water is then allowed to flow into the second heat exchanger 10 via the pipe 16.

Steam (water vapor) from a boiler or the like flows through the heat source fluid flow path of the steam heater 15.

The heat pump 20 is configured to compress a heat medium such as a refrigerant substitute from an evaporator 21 using a pump 22 and introduce it into a condenser 23, and then introduce the heat medium from the condenser 23 into the evaporator 21 via an expansion valve 24.

A circulation pump (not shown) is provided in the pipe 13. Pipes 25 and 26 are provided to pass the second water medium (heat pump heat source water) through the evaporator 21.

JP 2019-152411 A

As shown in FIG. 4, the amount of steam used for heating in the steam heater 15 is reduced by using a heat pump 20 to heat the first water medium circulating through the pipes 13, 14, and 16. However, the power consumption of a heat pump generally varies greatly depending on its operating conditions, and in some cases the benefit of reducing the amount of steam is offset by the power consumption of the heat pump, making it impossible to obtain the benefit of using the heat pump.

To address this issue, in order to obtain an energy saving effect that exceeds this offset, the heat pump's heat source water (second medium water) can be used as circulating water for the cooling tower, reducing the amount of steam and also reducing the power consumption of the cooling tower.

Cooling towers are designed to use the latent heat of vaporization to lower the temperature of water, and because their power consumption is mainly due to the cooling tower circulation pump and cooling fan, they are extremely efficient in heat exchange and are excellent in energy conservation (conservation) compared to heat pumps. However, because cooling towers consume less power than heat pumps, using cooling tower circulating water as the heat source water for a heat pump only slightly reduces power consumption, and the reality is that there is no real cost benefit to adopting a heat pump as an energy conservation measure.

By using return water (water that returns to the chiller after being heated at the point of use) from the chiller circulating water (hereinafter sometimes referred to as cold water) as the heat source water (second medium water) of the heat pump, it is possible to reduce the load on the chiller, which consumes more power than a cooling tower.

In general, the first water medium that flows into the second heat exchanger 10, which heats up the warm ultrapure water (approximately 75°C), is at approximately 80°C, so if the heat pump's heat source water is the return water (approximately 12°C) of the refrigeration unit circulating water, there is a large temperature difference with the first water medium.

Although the energy saving effect increases due to the reduction in the power consumption of the refrigerator, the increased temperature difference causes the heat pump's COP (coefficient of performance) to deteriorate compared to conventional methods, and power consumption increases. Considering the number of years it takes to recover the initial investment in adopting a heat pump through energy saving effects, it is not efficient in terms of cost benefits.

In addition, with hot ultrapure water systems, there is a problem on the manufacturing process side in that there is a large difference between the amount of hot ultrapure water used at the point of use during normal times and the amount used during maximum peak times.

If the system is configured to produce hot ultrapure water in accordance with the maximum peak of the use point and send it to the use point, the amount of hot ultrapure water used during normal times will be small, and therefore the amount of hot ultrapure water returned to the subtank during normal times will be large.

In Figure 4, the warm ultrapure water (return) returned from the use point and the ultrapure water from the subsystem are heat exchanged in the first heat exchanger 6. However, since the warm ultrapure water (return) does not drop to the room temperature ultrapure water temperature, there is a corresponding heat loss within the warm ultrapure water system.

In addition, the subsystem will need to use more cold water (refrigeration power consumption) to reduce the increased heat.

In light of the above, it was necessary to reexamine the hot ultrapure water system itself and establish an efficient energy-saving method by adopting a heat pump.

The present invention aims to provide a hot ultrapure water production apparatus that can efficiently save energy in a hot ultrapure water production apparatus that heats ultrapure water in a heat exchanger using a medium water heated by a heat pump.

The hot ultrapure water manufacturing apparatus of the first invention comprises a heat exchanger (A) for heating ultrapure water from an ultrapure water manufacturing apparatus, a hot ultrapure water storage tank for storing the ultrapure water heated by the heat exchanger (A) and unused return hot ultrapure water from a use point, a final heat exchanger for heating the ultrapure water from the hot ultrapure water storage tank to a temperature required at the use point, a hot ultrapure water supply path for supplying the hot ultrapure water heated by the final heat exchanger to the use point, a circulation path for circulating medium water as a heat source medium in the heat source fluid path of the heat exchanger (A), and a heat pump for heating the medium water flowing in the circulation path.

In one aspect of the first invention, the heat source water for the heat pump is return water from the refrigeration unit circulating water.

In one aspect of the first invention, a UF membrane device is provided in the hot ultrapure water supply path that supplies the hot ultrapure water heated in the final heat exchanger to a use point.

In one embodiment of the first invention, a heat exchanger (C) is provided to exchange heat between the return warm ultrapure water flowing from the use point to the warm ultrapure water storage tank and the concentrated water from the UF membrane device.

In one embodiment of the first invention, a heat exchanger (D) is provided between the ultrapure water production apparatus and the heat exchanger (A), and the concentrated water that has passed through the heat exchanger (C) passes through the heat exchanger (D) and is returned to the upstream side of the ultrapure water production apparatus.

In one aspect of the first invention, a final heat exchanger circulation flow path is provided that circulates a water medium as a heat source medium through the heat source fluid flow path of the final heat exchanger, and a final heat exchanger heat pump is provided that heats the water medium flowing through the final heat exchanger circulation flow path, and the heat source water for the final heat exchanger heat pump is the return water of the refrigeration unit circulation water.

The hot ultrapure water manufacturing apparatus of the second invention has a heat exchanger (A) for heating the ultrapure water from the ultrapure water manufacturing apparatus, a heat exchanger (B) for heating the ultrapure water heated by the heat exchanger (A), a final heat exchanger for heating the ultrapure water heated by the heat exchanger (B) to a temperature required at the use point, a hot ultrapure water supply path for supplying the hot ultrapure water heated by the final heat exchanger to the use point, a circulation path for circulating the medium water as a heat source medium in the heat source fluid path of the heat exchanger (A), a heat pump for heating the medium water flowing in the circulation path, and a return path for circulating the unused return hot ultrapure water not used at the use point as a heat source medium for the heat exchanger (B) and then returning it to a subtank of the ultrapure water manufacturing equipment or upstream thereof.

In one aspect of the second invention, a UF membrane device is provided in the hot ultrapure water supply path that supplies the hot ultrapure water heated in the final heat exchanger to a use point.

In one aspect of the second invention, a mixture of the return warm ultrapure water and concentrated water from the UF membrane device is circulated as the heat source medium for the heat exchanger (B).

In one embodiment of the second invention, a heat exchanger (D) is provided between the ultrapure water production apparatus and the heat exchanger (A), and the mixed water that has passed through the heat exchanger (B) is returned to the upstream side of the ultrapure water production apparatus through the heat exchanger (D).

In the hot ultrapure water manufacturing apparatus of the first invention, unused hot ultrapure water (return hot ultrapure water of about 70°C) is returned to the hot ultrapure water storage tank, so the temperature of the ultrapure water supplied to the heat exchanger (A) using a heat pump (a heat pump that heats the medium water flowing through the heat source fluid flow path of the heat exchanger (A)) is lower than in the conventional example (Figure 4) in which hot ultrapure water is returned to a sub-tank. This reduces the temperature difference between the heat source water of the heat pump (such as the return water of a refrigerator) and the medium water of the heat exchanger (A) (the heat source fluid of the heat exchanger (A)). This makes it possible to improve the COP (coefficient of performance) of the heat pump that heats the medium water flowing through the heat source fluid flow path of the heat exchanger (A).

In the hot ultrapure water production apparatus of the second invention, a heat exchanger (B) is installed downstream of the heat exchanger (A) in which the heat pump is installed. In this heat exchanger (B), the ultrapure water from the heat exchanger (A) is further heated by the return hot ultrapure water from the point of use (or a mixture of the return hot ultrapure water and the concentrated water from the UF membrane device).

In this way, the heat of the return hot ultrapure water is recovered and utilized in the rear stage of the heat exchanger (A), so the temperature of the ultrapure water supplied to the heat exchanger (A) can be lowered, as in the first invention. This reduces the temperature difference between the heat pump's heat source water (such as the return water of a refrigerator) and the medium water (the heat source fluid of the heat exchanger (A)). This makes it possible to improve the COP (coefficient of performance) of the heat pump.

In the first invention, unused ultrapure water circulates between the hot ultrapure water tank and the use point, so there is a risk of contamination accumulating due to piping, etc. In contrast, in the second invention, the return hot ultrapure water is returned to the ultrapure water production equipment after heat exchange, so contamination is removed and does not accumulate. Therefore, the second invention is suitable when the required water quality of the hot ultrapure water is high.

1 is a system diagram showing a warm ultrapure water manufacturing apparatus according to an embodiment of the first invention. FIG. 11 is a system diagram showing a warm ultrapure water manufacturing apparatus according to another embodiment of the first invention. FIG. 11 is a system diagram showing a warm ultrapure water manufacturing apparatus according to an embodiment of the second invention. FIG. 1 is a system diagram showing a conventional hot ultrapure water manufacturing apparatus.

The following describes the embodiment with reference to the drawings.

Figure 1 is a system diagram showing a warm ultrapure water production apparatus according to an embodiment of the first invention.

The primary pure water passes from sub-tank 1 through cooler 2, where it is cooled to approximately 23°C, before being introduced into subsystem 4 via pipe 3, where ultrapure water is produced. The ultrapure water produced flows through pipe 5, first heat exchanger 6 acting as heat exchanger (D), pipe 9, and second heat exchanger 10 acting as heat exchanger (A), in that order, and is heated to approximately 25-40°C by first heat exchanger 6, and then to approximately 45-60°C by second heat exchanger 10.

The ultrapure water heated by the second heat exchanger 10 is introduced into a hot ultrapure water tank 31, which serves as a hot ultrapure water storage tank, via piping 30. Return hot ultrapure water from the point of use 50 is also introduced into the hot ultrapure water tank 31 via piping 51, the fourth heat exchanger 52, and piping 53. In order to keep the water level in the hot ultrapure water tank 31 constant, it is preferable to provide a flow control valve (not shown) in the piping 30.

The hot ultrapure water in the hot ultrapure water tank 31 is introduced into the third heat exchanger 33 as the final heat exchanger via piping 32, heated to about 75°C, and then supplied to the UF membrane device 40 via piping 34. The hot ultrapure water consisting of the permeate from the UF membrane device is sent to the point of use 50 via piping 41. The return hot ultrapure water from the point of use 50 is sent to the hot ultrapure water tank 31 via piping 51, the fourth heat exchanger 52 as the heat exchanger (C), and piping 53, as described above.

The concentrated water from the UF membrane device 40 has a temperature of about 72-78°C and is sent to the fourth heat exchanger 52 via pipe 42, where it is cooled to about 68-74°C through heat exchange with the return ultrapure water from pipe 51, and then sent to the first heat exchanger 6 via pipe 43. The return ultrapure water is cooled to about 23-30°C through heat exchange with the ultrapure water from the subsystem 4 in the first heat exchanger 6, and sent to the subtank 1 via pipe 8. The return ultrapure water from pipe 8 may also be sent to a tank upstream of the subtank 1 (for example, the tank of the primary pure water device).

The first water medium (water as a heat transfer medium) heated by the heat pump 20 is circulated through the heat source fluid flow path of the first heat exchanger 10. That is, the first water medium that has passed through the heat source fluid flow path of the heat exchanger 10 is heated by passing it through the condenser 23 of the heat pump 20 via the piping 13, the tank 13a, and the circulation pump (not shown), and then flows into the heat source fluid flow path of the first heat exchanger 10 via the piping 14.

The heat pump 20 is configured to compress a heat medium such as a refrigerant substitute from an evaporator 21 using a pump 22 and introduce it into a condenser 23, and then introduce the heat medium from the condenser 23 into the evaporator 21 via an expansion valve 24.

A flow path consisting of a forward pipe 25 and a return pipe 26 is provided to pass the second medium water (heat pump heat source water) through the heat source fluid flow path (low temperature side flow path) of the evaporator 21.

In this embodiment, return water from the refrigerator (not shown) that is circulated at about 8 to 20°C is passed through the evaporator 21 as the heat pump heat source water. The return water that has been heated through the evaporator 21 is returned to the refrigerator via the pipe 26.

The medium water is passed through the heat source fluid flow path of the third heat exchanger 33 via circulation pipes 35, 37, 39, a circulation water tank 36, and a pump (not shown). A steam heater 38 is provided between these pipes 37 and 39. The medium water heated by the steam heater 38 is passed through the heat exchanger 33, and the warm ultrapure water from pipe 32 is further heated by the medium water and sent to the UF membrane device 40 through pipe 34.

In the warm ultrapure water production apparatus of FIG. 1 configured in this manner, the ultrapure water from the subsystem 4 is heated in the first heat exchanger 6 by heat exchange with the concentrated water from the UF membrane device 40, and then further heated in the second heat exchanger 10 using the medium water heated by the heat pump 20, before flowing into the warm ultrapure water tank 31. The return warm ultrapure water and the mixture of this warm ultrapure water are further heated in the third heat exchanger 33, and then sent to the point of use 50 via the UF membrane device 40. The return warm ultrapure water from the point of use 50 is heat exchanged with the concentrated water from the UF membrane device 40 in the fourth heat exchanger 52, where it is slightly heated, before flowing into the warm ultrapure water tank 31.

In this embodiment, the temperature of the ultrapure water supplied to the second heat exchanger 10 can be lowered compared to the conventional example (Figure 4) in which unused warm ultrapure water (approximately 70°C) is returned to the subsystem 4, so the temperature difference between the heat source water (such as the return water of the refrigerator) of the heat pump 20 used to heat the second heat exchanger 10 and the second medium water (the heat source fluid of the second heat exchanger 10) is reduced. This makes it possible to improve the COP (coefficient of performance) of the heat pump.

In this embodiment, the heat pump's heat absorption source is the return water of the chiller circulating water, which reduces the power consumption of the chiller by a smaller amount than the power reduction achieved by conventional systems using cooling towers.

In this embodiment, the return hot ultrapure water from the point of use 50 is returned to the hot ultrapure water tank 31, so the amount of power consumed by the refrigerator for cooling by the cooler 2 is reduced compared to when the hot ultrapure water is returned to the sub-tank 31. This makes it possible to enjoy the substantial cost benefits of introducing a heat pump into the hot ultrapure water system.

In this embodiment, hot ultrapure water is returned from the point of use 50 to the hot ultrapure water tank 31, and only the concentrated water (UF brine) from the UF membrane device 40 releases heat to the subsystem 4. In this embodiment, heat is recovered from the UF brine by the fourth heat exchanger 52 and the first heat exchanger 6, so there is little heat loss (cooling heat in the subsystem) in the hot ultrapure water system. For this reason, while in the conventional example the less hot ultrapure water was used the more heat loss there was in the system, heat loss is reduced regardless of the amount used, and the amount of heat required to heat the hot ultrapure water device is accordingly reduced.

In addition, the amount of heat absorbed by the return warm ultrapure water from the UF brine by the fourth heat exchanger 52 is small compared to the amount of return warm ultrapure water passing through the fourth heat exchanger 52, so the temperature rise of the return warm ultrapure water is small. For this reason, the heat pump 20 does not need to raise the hot water temperature to about 80°C as in the conventional case. This reduces the temperature difference between the heat absorption source side outlet and the hot water side outlet in the heat pump 20, improving the COP and reducing power consumption.

When two or more heat pumps are installed in the medium water line of the second heat exchanger 10, it is desirable to pass the return water of the chiller circulating water in series to reduce the temperature difference with the heat absorption side and reduce power consumption.

In FIG. 1, only one heat pump 20 for heating the medium water of the heat exchanger 10 is provided, but two or more may be provided. In this case, it is preferable that the return water as the heat source water is passed in series through the evaporators of each heat pump. Furthermore, if the amount of water is large, multiple heat pumps can be installed in parallel. For example, two series of six heat pumps connected in series can be installed.

Figure 2 is a system diagram showing another embodiment of the first invention.

In the embodiment of FIG. 1, the heat source medium water of the third heat exchanger 33 is heated only by the steam heater 38, but in the embodiment of FIG. 2, this heat source medium water is heated by the heat pumps 20A and 20B and the steam heater 38.

Heat pumps 20A and 20B have the same configuration as heat pump 20, and each includes an evaporator 21, a pump 22, a condenser 23, and an expansion valve 24.

After the ultrapure water is heated in the third heat exchanger 33, the medium water is passed through piping 35 and circulating water tank 36 to the condenser 23 of the first heat pump 22A and heated, then passed through piping 35A to the condenser 23 of the second heat pump 22B and heated, and then sent via piping 37 to the steam heater 38 where it is further heated, and then sent via piping 39 to the third heat exchanger 33.

Refrigeration circulating water return water is passed as heat source water to the evaporator 21 of the first heat pump 20A through a pipe 25A branched off from the heat source water pipe 25 for the heat pump.

The return water, which has been cooled through the evaporator 21 of the first heat pump 20A, is passed through pipe 26A to the evaporator 21 of the second heat pump 20B, where it is further cooled, and is returned to the refrigerator through pipe 26B.

The rest of the configuration of the warm ultrapure water production apparatus in Figure 2 is the same as in Figure 1, and the same symbols indicate the same parts.

In the hot ultrapure water production apparatus of FIG. 2, heat pumps 20A and 20B are installed in the hot water circulation line of heat exchanger 33. This makes it possible to reduce (or eliminate) the amount of steam used in steam heater 38. Note that, although two heat pumps 20A and 20B are installed in FIG. 2, only one may be used. When multiple heat pumps are installed, it is preferable to pass return water through two series stages as shown in FIG. 2.

By passing water in series, the power consumption of the heat pump is reduced accordingly. In this embodiment, the heat pump's heat absorption source (heat source water) is the return water, so the power consumption of the refrigerator is reduced accordingly compared to conventional methods.

Figure 3 is a system diagram showing a warm ultrapure water production apparatus according to an embodiment of the second invention.

In FIG. 3, a fifth heat exchanger 62 as a heat exchanger (B) is installed between the second heat exchanger 10 as a heat exchanger (A) and the third heat exchanger 30 as a final heat exchanger. A pipe 51 for return warm ultrapure water from the use point 50 and a pipe 42 for concentrated water (brine) from the UF membrane device 40 are connected to the junction pipe 62.

The return warm ultrapure water from the point of use 50 and the concentrated water from the UF membrane device 40 are passed through the heat source fluid flow path of the fifth heat exchanger 62 via pipes 51, 42 and pipe 61, and after heat exchange with the ultrapure water from pipe 30, are passed through pipe 63 to the heat source fluid flow path of the first heat exchanger 6, and then sent to the subtank 1 via pipe 8.

The rest of the configuration of the warm ultrapure water production apparatus in Figure 3 is the same as in Figure 1, and the same symbols indicate the same parts.

According to the hot ultrapure water manufacturing apparatus of FIG. 3, the return hot ultrapure water is passed through the heat source fluid flow path of the fifth heat exchanger 62 as a heat exchanger (B), and after recovering heat from the return hot ultrapure water (i.e., after lowering the temperature of the return hot ultrapure water), it is passed through the heat source fluid flow path of the first heat exchanger 6, and then returned to the sub-tank 1. As a result, the amount of heat given to the ultrapure water in the first heat exchanger 6 is less than in the conventional case (FIG. 4), and the temperature of the ultrapure water supplied from the first heat exchanger 6 to the second heat exchanger 10 is lower than in the conventional case (FIG. 4). As a result, the temperature difference between the heat source water (in this embodiment, the return water of the refrigeration circulating water) of the heat pump 20 used to heat the medium water of the second heat exchanger 10 and the medium water is smaller than in the conventional case (FIG. 4), so that the COP (coefficient of performance) of the heat pump can be improved.

In addition, in Figures 1 and 2, unused ultrapure water circulates between the hot ultrapure water tank 31 and the use point 50, so there is a risk of contamination accumulating due to piping, etc., but in Figure 3, the return hot ultrapure water from the use point passes through sub-tank 1 and is treated in subsystem 4, so contamination is removed without accumulating. Therefore, the hot ultrapure water manufacturing device in Figure 3 is suitable when the required quality of hot ultrapure water is high.

However, in FIG. 3, the fifth heat exchanger 62 cannot fully recover the heat of the return ultrapure water, so the power reduction effect is reduced.

[Comparative Example 1]
The warm ultrapure water production apparatus shown in FIG. 4 was operated under the following conditions.
Primary pure water temperature: 23℃
Water temperature from subtank 1: 23.3℃
Temperature and flow rate of ultrapure water from subsystem 4: 23° C., 90 m ³ /h
Temperature and flow rate of ultrapure water from the first heat exchanger 6: 59.8° C., 90 m ³ /h
Temperature and flow rate of ultrapure water from the second heat exchanger 10: 75° C., 90 m ³ /h
Temperature and flow rate of hot ultrapure water from the UF membrane device 40 to the use point: 75° C., 85.5 m ³ /h
Temperature and flow rate of ultrapure water returned from the use point: 70° C., 69 m ³ /h
Temperature and flow rate of concentrated water from the UF membrane device 40: 75° C., 4.5 m ³ /h
Temperature and flow rate of the mixture of ultrapure water and concentrated water returned from the first heat exchanger 6 to the subtank 1 at the use point: 25° C., 73.5 m ³ /h
Temperature and flow rate of return water sent from the refrigerator to the evaporator 21 of the heat pump 20 via the pipe 25: 12° C., 108 m ³ /h
Temperature and flow rate of return water from the evaporator 21 to the refrigerator: 7° C., 108 m ³ /h
Temperature and flow rate of hot water from the condenser 23 of the heat pump 20 to the steam heater 15 (through the pipe 14): 72.3° C., 108 m ³ /h
Temperature and flow rate of hot water from steam heater 15 (through pipe 14) to heat exchanger 10: 80° C., 108 m ³ /h
Temperature and flow rate of hot water from the heat exchanger 10 (through the pipe 13) to the condenser 23 of the heat pump 20: 67.3° C., 108 m ³ /h

The thermal calculation results were as follows:
Heat exchanger 6 calorific value: 3308 Mcal/h
3846kw
Heat exchanger 10 heat amount: 1373 Mcal/h
1596kw
Steam heater 15 heat quantity: 832 Mcal/h
967kw
Heat pump 20 heat exchange amount (heating): 541 Mcal/h
629kw
Steam heater 15 + heat pump 20 Heating capacity: 1,373 Mcal/h
1,596kw
Heat pump 20 COP: 3.0
Power consumption of heat pump 20: 210 kW

[Example 1]
The warm ultrapure water production apparatus shown in FIG. 1 was operated under the following conditions.
Primary pure water temperature: 23℃
Water temperature from subtank 1: 23°C
Temperature and flow rate of ultrapure water from subsystem 4: 23° C., 21 m ³ /h
Temperature and flow rate of ultrapure water from the first heat exchanger 6: 32.9° C., 21 m ³ /h
Temperature and flow rate of ultrapure water from the second heat exchanger 10: 50° C., 21 m ³ /h
Temperature and flow rate of ultrapure water from the hot ultrapure water tank 31: 65.5° C., 90 m ³ /h
Temperature and flow rate of hot ultrapure water from the third heat exchanger 33: 75° C., 90 m ³ /h
Temperature and flow rate of hot ultrapure water from the UF membrane device 40 to the use point: 75° C., 85.5 m ³ /h
Temperature and flow rate of ultrapure water returned from the use point: 70° C., 69 m ³ /h
Temperature and flow rate of the return hot ultrapure water from the fourth heat exchanger 52 to the hot ultrapure water tank 31: 70.3° C., 69 m ³ /h
Temperature and flow rate of concentrated water from the UF membrane device 40: 75° C., 4.5 m ³ /h
Temperature and flow rate of concentrated water from the fourth heat exchanger 52 to the first heat exchanger 6: 71° C., 4.5 m ³ /h
Temperature and flow rate of concentrated water from the first heat exchanger 6 to the subtank 1: 25° C., 4.5 m ³ /h
Temperature and flow rate of return water sent from the refrigerator to the evaporator 21 of the heat pump 20 via the pipe 25: 12° C., 72 m ³ /h
Temperature and flow rate of return water from the evaporator 21 to the refrigerator: 7° C., 72 m ³ /h
Temperature and flow rate of hot water from the condenser 23 of the heat pump 20 to the heat exchanger 10 (through the pipe 14): 55° C., 108 m ³ /h
Temperature and flow rate of hot water from the heat exchanger 10 (through the pipe 13) to the condenser 23 of the heat pump 20: 51.7° C., 108 m ³ /h
Temperature and flow rate of hot water from steam heater 38 (through pipe 39) to heat exchanger 33: 80° C., 108 m ³ /h
Temperature and flow rate of hot water from the heat exchanger 33 (through the pipe 35 and the circulating water tank 36) to the steam heater 38: 72.1° C., 108 m ³ /h

The thermal calculation results were as follows:
Heat exchanger 52 heat amount: 18 Mcal/h
21kw
Heat exchanger 6 calorific value: 207 Mcal/h
241kw
Heat exchanger 10 heat amount: 360 Mcal/h
419kw
Heat exchanger 33 heat amount: 852 Mcal/h
991kw
Steam heater 38 Heat capacity: 852 Mcal/h
991kw
Heat pump 20 heat exchange amount (heating): 360 Mcal/h
419kw
Steam heater 38 + heat pump 20 Heating capacity: 1,212 Mcal/h
1,409kw
COP of heat pump 20: 4.1
Power of heat pump 20: 102 kW
Reduction rate of power consumption of heat pump 20: 51% (vs. Comparative Example 1)

[Example 2]
The warm ultrapure water production apparatus shown in FIG. 3 was operated under the following conditions.
Primary pure water temperature: 23℃
Water temperature from subtank 1: 23.3℃
Temperature and flow rate of ultrapure water from subsystem 4: 23° C., 90 m ³ /h
Temperature and flow rate of ultrapure water from the first heat exchanger 6: 45.1° C., 90 m ³ /h
Temperature and flow rate of ultrapure water from the second heat exchanger 10: 50° C., 90 m ³ /h
Temperature and flow rate of ultrapure water from the fifth heat exchanger 62: 64.7° C., 90 m ³ /h
Temperature and flow rate of hot ultrapure water from the third heat exchanger 33: 75° C., 90 m ³ /h
Temperature and flow rate of hot ultrapure water from the UF membrane device 40 to the use point: 75° C., 85.5 m ³ /h
Temperature and flow rate of ultrapure water returned from the use point: 70° C., 69 m ³ /h
Temperature and flow rate of concentrated water from the UF membrane device 40: 75° C., 4.5 m ³ /h
Temperature and flow rate of return water from the fifth heat exchanger 62 to the first heat exchanger 6: 52° C., 73.5 m ³ /h
Temperature and flow rate of return water from the first heat exchanger 6 to the sub-tank 1: 25°C, 73.5 ^m3 /h
Temperature and flow rate of return water sent to the evaporator 21 of the heat pump 20: 12° C., 89 m ³ /h
Temperature and flow rate of return water from the evaporator 21 of the heat pump 20: 7° C., 89 m ³ /h
Temperature and flow rate of hot water from the condenser 23 of the heat pump 20 to the heat exchanger 10 (through the pipe 14): 55° C., 108 m ³ /h
Temperature and flow rate of hot water from the heat exchanger 10 (through the pipe 13) to the condenser 23 of the heat pump 20: 50.9° C., 108 m ³ /h
Temperature and flow rate of hot water from steam heater 38 (through pipe 39) to heat exchanger 33: 80° C., 108 m ³ /h
Temperature and flow rate of hot water from heat exchanger 33 (through pipe 35) to steam heater 38: 71.4° C., 108 m ³ /h

The thermal calculation results were as follows:
Heat exchanger 52 heat amount: 1,323 Mcal/h
1,538kw
Heat exchanger 6 calorific value: 1,985 Mcal/h
2,308kw
Heat exchanger 10 heat amount: 446 Mcal/h
518kw
Heat exchanger 33 heat amount: 927 Mcal/h
1,078kw
Steam heater 38 Heat capacity: 927 Mcal/h
1,078kw
Heat pump 20 heat exchange amount (heating): 446 Mcal/h
518kw
Steam heater 38 + heat pump 20 Heating capacity: 1,373 Mcal/h
1,596kw
COP of heat pump 20: 4.1
Power consumption of heat pump 20: 126 kW
Reduction rate of power consumption of heat pump 20: 40% (vs. Comparative Example 1)

1 Sub-tank 2 Cooling tower 4 Sub-system (ultrapure water production equipment)
6 First heat exchanger (heat exchanger (D))
10 Second heat exchanger (heat exchanger (A))
12, 40 UF membrane device 15, 38 Steam heater 20, 20A, 20B Heat pump 31 Hot ultrapure water tank (hot ultrapure water storage tank)
33 Third heat exchanger (final heat exchanger)
50 Use point 52 Fourth heat exchanger (heat exchanger (C))
62 Fifth heat exchanger (heat exchanger (B))

Claims (10)

A heat exchanger (A) for heating ultrapure water from an ultrapure water production apparatus;
a warm ultrapure water storage tank for storing the ultrapure water heated by the heat exchanger (A) and unused return warm ultrapure water from a use point;
a final heat exchanger for heating the ultrapure water from the hot ultrapure water storage tank to a required temperature at a point of use;
a hot ultrapure water supply line for supplying the hot ultrapure water heated by the final heat exchanger to a use point;
a circulation flow path for circulating a medium water as a heat source medium through a heat source fluid flow path of the heat exchanger (A);
and a heat pump for heating the medium water flowing through the circulation flow path. The warm ultrapure water production apparatus of claim 1, characterized in that the heat source water for the heat pump is return water from the refrigeration unit circulation water. The warm ultrapure water production apparatus of claim 1 or 2, wherein a UF membrane device is provided in a warm ultrapure water supply path that supplies the warm ultrapure water heated by the final heat exchanger to a use point. The warm ultrapure water production apparatus of claim 3 is provided with a heat exchanger (C) for exchanging heat between the return warm ultrapure water flowing from the use point to the warm ultrapure water storage tank and the concentrated water from the UF membrane device. a heat exchanger (D) is provided between the ultrapure water production apparatus and the heat exchanger (A);
5. The apparatus for producing warm ultrapure water according to claim 4, wherein the concentrated water having passed through said heat exchanger (C) is returned to the upstream side of said ultrapure water producing apparatus through said heat exchanger (D). a final heat exchanger circulation flow path for circulating a medium water as a heat source medium through a heat source fluid flow path of the final heat exchanger;
a final heat exchanger heat pump that heats the medium water flowing through the final heat exchanger circulation flow path,
2. The apparatus for producing warm ultrapure water according to claim 1, wherein the heat source water for said final heat exchanger heat pump is return water of circulating water from a refrigerator. A heat exchanger (A) for heating ultrapure water from an ultrapure water production apparatus;
a heat exchanger (B) for heating the ultrapure water heated by the heat exchanger (A);
a final heat exchanger for heating the ultrapure water heated by the heat exchanger (B) to a required temperature at a point of use;
a hot ultrapure water supply line for supplying the hot ultrapure water heated by the final heat exchanger to a use point;
a circulation flow path for circulating a water medium as a heat source medium through a heat source fluid flow path of the heat exchanger (A); and a heat pump for heating the water medium flowing through the circulation flow path;
a return line for circulating unused return-temperature ultrapure water that has not been used at the point of use as a heat source medium for the heat exchanger (B) and then returning the water to a sub-tank of the ultrapure water producing apparatus or to an upstream thereof ;
The hot ultrapure water production apparatus uses return water from the circulating chiller as the heat source water for the heat pump . The warm ultrapure water production apparatus of claim 7, wherein a UF membrane device is provided in a warm ultrapure water supply path that supplies the warm ultrapure water heated by the final heat exchanger to a use point. The warm ultrapure water production apparatus of claim 8, in which a mixture of the return warm ultrapure water and concentrated water from the UF membrane device is circulated as the heat source medium for the heat exchanger (B). a heat exchanger (D) is provided between the ultrapure water production apparatus and the heat exchanger (A);
10. The apparatus for producing warm ultrapure water according to claim 9, wherein the mixed water having passed through the heat exchanger (B) is returned to the upstream side of the ultrapure water producing apparatus through the heat exchanger (D).

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