Warm ultrapure water production system and warm ultrapure water production method

Abstract

Provided is a warm ultrapure water production system which has a preheater 10 and a heater 11 for heating ultrapure water at a stage subsequent to a non-regenerative ion exchange resin column 9 of a secondary pure water device 1, and in which a heat source 12 is connected to the heater 11 via a flow rate regulating valve 13. Further, warm ultrapure water W1 can be supplied to a use point UP through a UF membrane 14. A return piping 20 branches from a water supply piping 2A at a stage subsequent to the UF membrane 14, and the return piping 20 returns to a sub tank 2 via the preheater 10. The return piping 20 is provided with a pressure regulating valve 16 and a flow meter 18, and a water supply amount of primary pure water W from a water supply pump 3 and a booster pump 8 can be regulated on the basis of flow rate data of the flow meter 18. According to such a warm ultrapure water production system, the production amount of warm ultrapure water can be controlled in accordance with the usage amount of the warm ultrapure water, and the energy required for the production of the warm ultrapure water can be reduced.

Description

Warm ultrapure water production system and method for producing warm ultrapure water

[0001] The present invention relates to a warm ultrapure water production system that can reduce the energy required to produce warm ultrapure water by controlling the amount of warm ultrapure water produced in accordance with the amount of warm ultrapure water used at the point of use, and to a method for producing warm ultrapure water using the same.

[0002] Ultrapure water used for semiconductor cleaning is produced by treating raw water (industrial water, city water, well water, etc.) in an ultrapure water production system that includes a pretreatment system, a primary pure water production system, and a subsystem (secondary pure water production system).

[0003] The pretreatment system, which consists of coagulation, flotation (sedimentation), and filtration (membrane filtration) equipment, removes suspended solids and colloidal matter from the raw water. This process also makes it possible to remove polymeric organic matter and hydrophobic organic matter.

[0004] The primary water purification system includes a heat exchanger, a reverse osmosis membrane treatment device (RO device), an ion exchange device (mixed-bed type or four-bed five-tower type, etc.), an ion exchange device, a degassing device, etc. The primary water purification system removes ions and organic components from raw water. Note that the higher the water temperature, the lower the viscosity and the higher the RO membrane permeability. For this reason, a heat exchanger is installed upstream of the reverse osmosis membrane treatment device to heat the water supplied to the reverse osmosis membrane treatment device so that the temperature is above a predetermined temperature. The reverse osmosis membrane treatment device removes salts, as well as ionic and total organic compounds (TOC). The ion exchange device removes salts and inorganic carbon (IC) and also removes TOC components adsorbed or ion-exchanged by the ion exchange resin. The degassing device removes inorganic carbon (IC) and dissolved oxygen.

[0005] The primary pure water produced in the primary pure water production system is sent to a subsystem, which is equipped with a sub-tank (pure water tank), a low-pressure ultraviolet oxidation device (UV device), an ion exchange device, etc. In the low-pressure ultraviolet oxidation device, the 185 nm ultraviolet light emitted from a low-pressure ultraviolet lamp is used to convert TOC into organic acids and further CO ２ The organic matter and CO2 produced by the decomposition are removed in the downstream ion exchange unit.

[0006] The ultrapure water produced in such an ultrapure water system is sometimes heated to about 65 to 85° C. by a heating means and supplied to a point of use as hot ultrapure water.

[0007] This hot ultrapure water production system has a configuration, for example, as shown in FIG. 2. In FIG. 2, the hot ultrapure water production system includes a secondary water purification system (subsystem) 51, which includes a subtank 52 for storing primary pure water W at approximately 25°C from the primary pure water purification system, a water supply pipe 52A as a hot ultrapure water supply line, a water pump 53, a heat exchanger 54, an ultraviolet oxidation device 55, a hydrogen peroxide decomposition device 56 filled with a platinum catalyst, a membrane degassing device 57, a booster pump 58, and a non-regenerative ion exchange resin tower 59. Ultrapure water at approximately 20 to 30°C is produced in this system. The system also includes a preheater 60 and a heater 61 for heating the ultrapure water. A heat source 62 is connected to the heater 61 via a flow control valve 63 as a flow control mechanism. The system also includes a UF membrane 64 for removing particulates from the heated ultrapure water. Hot ultrapure water W1 can be supplied to a point-of-use (UP) via the UF membrane 64.

[0008] A temperature sensor 65 serving as a means for measuring the temperature of the hot ultrapure water is provided at the outlet of the heater 61, and this temperature sensor 65 is capable of transmitting information to control means (not shown), which is capable of adjusting the aperture of a flow control valve 63 to control the flow rate of the heat source 62. Furthermore, a return pipe 70 branches off from the water supply pipe 52A downstream of the UF membrane 64, and this return pipe 70 returns water to the sub-tank 52 via the preheater 60. A pressure control valve 66 and a pressure sensor 67 serving as a pressure measurement means are provided in this return pipe 70, and this pressure sensor 67 is capable of transmitting information to control means, which is capable of adjusting the aperture of the pressure control valve 66 based on the pressure data.

[0009] In this secondary pure water system 51, primary pure water W at approximately 25°C is stored in a sub-tank 52 from the primary pure water system, and then supplied by a water pump 53 through a water supply pipe 52A. Ultrapure water at approximately 20 to 30°C is produced by sequentially treating the water in an ultraviolet oxidation device 55, a hydrogen peroxide decomposition device 56, a membrane degassing device 57, and a non-regenerative ion exchange resin tower 59. The produced ultrapure water is heated to 30 to 50°C, for example, approximately 42°C, by a preheater 60, and then heated to 65 to 85°C, for example, approximately 75°C, by a heater 61. A required amount of hot ultrapure water W1 is then supplied from the water supply pipe 52A to the point of use UP via a UF membrane 64.

[0010] The temperature of the hot ultrapure water W1 is controlled to a predetermined temperature based on the value measured by a temperature sensor 65 provided downstream of the heater 61, and the flow rate adjustment valve 63 is controlled to control the amount of heat medium supplied from the heat source 62. Furthermore, surplus hot ultrapure water W1 not used at the point of use UP passes through the return pipe 70, has heat recovered in the preheater 60, and then returns to the subtank 52. At this time, the opening of the pressure adjustment valve 66 is adjusted so that the pressure measured by the pressure sensor 67 in the water supply pipe 52A to the point of use UP and in the return pipe 70 remains constant, thereby maintaining the water supply pressure to the point of use UP constant.

[0011] However, in the conventional warm ultrapure water production system described above, a fixed amount of warm ultrapure water W1 is produced, and if the amount of warm ultrapure water used at the use point UP is less than expected, the amount of water sent to the use point UP is adjusted by increasing the amount returned, which creates the problem that there is room for reducing the energy required for heating and water supply power.

[0012] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a warm ultrapure water production system that can reduce the energy required to produce warm ultrapure water by controlling the amount of warm ultrapure water produced in accordance with the amount of warm ultrapure water used at the point of use, and a method for producing warm ultrapure water using the same.

[0013] In view of the above object, firstly, the present invention provides a system including an ultrapure water production unit having a primary pure water production apparatus and a secondary pure water production apparatus, a hot ultrapure water supply pipe for supplying ultrapure water from the ultrapure water production unit to a use point, a first heating means provided in the ultrapure water supply pipe for supplying heat source water to a heat source fluid flow path as heat source water via return water in excess of the amount used at the use point, a return pipe for returning the return water that has passed through the heat source fluid flow path of the first heating means to the ultrapure water production unit, and a second heating means for further heating the ultrapure water heated by the first heating means, We provide a hot ultrapure water manufacturing system in which heated ultrapure water is supplied to a use point, the system comprising: a flow rate measuring means, a pressure measuring means, and a pressure regulating valve provided downstream of the pressure measuring means in the return pipe; a temperature measuring means provided downstream of the second heating means in the hot ultrapure water supply pipe; and control means for controlling the pressure regulating valve based on the measurement value of the pressure measuring means, controlling the amount of ultrapure water supplied based on the measurement value of the flow rate measuring means, and controlling the second heating means based on the measurement value of the temperature measuring means (Invention 1).

[0014] According to this invention (Invention 1), the pressure regulating valve provided in the return pipe can be controlled so that the measurement value of the pressure measuring means upstream of the valve remains approximately constant, and the supply amount of ultrapure water can be controlled so that the measurement value of the flow rate measuring means remains approximately constant. Therefore, when the amount of warm ultrapure water used at the point of use decreases, the supply amount of ultrapure water can be reduced, thereby reducing the energy required for heating and water supply power and allowing the warm ultrapure water production system to be operated to produce warm ultrapure water.

[0015] In the above invention (Invention 1), it is preferable that the secondary pure water production system has a water pump, and that the control means adjusts the supply amount of ultrapure water by controlling the output of the water pump (Invention 2). Also, in the above invention (Invention 1), it is preferable that the secondary pure water production system has a water pump and a boost pump downstream of the water pump, and that the control means adjusts the supply amount of ultrapure water by controlling the water pump and / or the boost pump (Invention 3). Furthermore, in the above invention (Invention 3), it is preferable that the water pump and the boost pump are equipped with inverters, that the control means controls the frequency output from the inverter, and that the lower limit of fluctuation in the amount of water used at the point of use is 50% or more of the maximum (Invention 4).

[0016] According to these inventions (Inventions 2 to 4), by adjusting the water supply rate of the water supply pump and / or boost pump provided in the secondary pure water production apparatus using inverter control or the like, ultrapure water can be supplied quickly and in a wide range of water amounts in response to fluctuations in the use of warm ultrapure water at the point of use.

[0017] Secondly, the present invention provides a system for generating ultrapure water from a point of use, the system comprising: an ultrapure water generating unit having a primary pure water generating apparatus and a secondary pure water generating apparatus; a hot ultrapure water supply line for supplying ultrapure water from the ultrapure water generating unit to a point of use; a first heating means provided in the ultrapure water supply line for supplying heat source water to a heat source fluid flow path via return water in excess of the amount used at the point of use; a return pipe for returning the return water that has passed through the heat source fluid flow path of the first heating means to the ultrapure water generating unit; and a second heating means for further heating the ultrapure water heated by the first heating means, the ultrapure water heated by the second heating means being supplied to the point of use; A method for producing warm ultrapure water using a warm ultrapure water production system is provided in which a flow rate measuring means, a pressure measuring means, and a pressure regulating valve are provided in the return pipe downstream of the pressure measuring means, and a temperature measuring means is provided downstream of the second heating means in the warm ultrapure water supply pipe, wherein the pressure regulating valve is controlled so that the measurement value of the pressure measuring means becomes approximately constant, the amount of ultrapure water supplied is controlled so that the measurement value of the flow rate measuring means becomes approximately constant, and the second heating means is controlled so that the measurement value of the temperature measuring means becomes constant at a temperature higher than the set temperature of the warm ultrapure water (Invention 5).

[0018] According to this invention (Invention 5), the pressure regulating valve provided in the return pipe can be controlled so that the measurement value of the pressure measuring means is kept approximately constant upstream of the pressure regulating valve, and the amount of ultrapure water supplied can be controlled so that the measurement value of the flow rate measuring means is kept approximately constant. Therefore, when the amount of warm ultrapure water used at the point of use decreases, the amount of ultrapure water supplied can be reduced, thereby reducing the energy required for heating and water supply power and allowing the warm ultrapure water producing system to be operated to produce warm ultrapure water.

[0019] In the above invention (Invention 5), it is preferable that the secondary pure water production system has a water pump, and that the control means adjusts the supply amount of ultrapure water by controlling the output of the water pump (Invention 6). Also, in the above invention (Invention 5), it is preferable that the secondary pure water production system has a water pump and a boost pump downstream of the water pump, and that the control means adjusts the supply amount of ultrapure water by controlling the water pump and / or the boost pump (Invention 7). Furthermore, in the above invention (Invention 7), it is preferable that the water pump and the boost pump are equipped with inverters, that the control means controls the frequency output from the inverter, and that the lower limit of fluctuation in the amount of water used at the point of use is 50% or more of the maximum value (Invention 8).

[0020] According to such inventions (Inventions 5 to 8), by adjusting the water supply rate of the water supply pump and / or boost pump provided in the secondary pure water production apparatus using inverter control or the like, ultrapure water can be supplied quickly and in a wide range of water amounts in response to fluctuations in the use of warm ultrapure water at the point of use.

[0021] According to the warm ultrapure water manufacturing system of the present invention, the pressure regulating valve installed in the return pipe can be controlled so that the measurement value of the pressure measuring means is approximately constant upstream of the pressure regulating valve, and the amount of ultrapure water supplied can be controlled so that the measurement value of the flow rate measuring means is approximately constant.Therefore, when the amount of warm ultrapure water used at the point of use decreases, the amount of ultrapure water supplied can be reduced, thereby reducing the energy required for heating and water supply power and allowing the warm ultrapure water manufacturing system to be operated to produce warm ultrapure water.

[0022] 1 is a flow diagram showing a hot ultrapure water producing system according to an embodiment of the present invention, and FIG. 2 is a flow diagram showing a conventional hot ultrapure water producing system.

[0023] The warm ultrapure water producing system and the method for producing warm ultrapure water using the same of the present invention will be described below with reference to the accompanying drawings.

[0024] (Warm ultrapure water production system) The warm ultrapure water production system of this embodiment has an ultrapure water production unit equipped with a pretreatment device, a primary pure water production device, and a secondary pure water production device, a warm ultrapure water supply pipeline that supplies ultrapure water from this ultrapure water production unit to a use point, and a heating means that heats the ultrapure water.

[0025] In this embodiment, the primary pure water production system is not particularly limited, and a known primary pure water production system can be applied under normal control, so a detailed description thereof will be omitted.

[0026] The hot ultrapure water producing system of this embodiment has a configuration as shown in Fig. 1. In Fig. 1, the hot ultrapure water producing system includes a secondary pure water system (subsystem) 1, which includes a subtank 2 for storing primary pure water W delivered from the primary pure water system, a water supply pipe 2A as a hot ultrapure water supply line, a water pump 3 whose output can be controlled by an inverter, a heat exchanger 4, an ultraviolet oxidation device 5, a hydrogen peroxide decomposition device 6 filled with a platinum group metal catalyst, a membrane degassing device 7, a boost pump 8 whose output can be controlled by an inverter, and a non-regenerative ion exchange resin tower 9. The hot ultrapure water producing system also includes a preheater 10 as a first heating means for heating the ultrapure water, and a heater 11 as a second heating means. A heat source 12 is connected to the heater 11 via a flow control valve 13 as a flow control mechanism, allowing the flow rate to be adjusted. The system also includes a UF membrane 14 for removing particulates from the heated ultrapure water, so that the hot ultrapure water W1 can be supplied to a point-of-use (UP) via the UF membrane 14.

[0027] A temperature sensor 15 is provided at the outlet of the heater 11 as a means for measuring the temperature of the hot ultrapure water W1, and this temperature sensor 15 is capable of transmitting information to control means (not shown), which is capable of adjusting the aperture of a flow control valve 13 of the heat source 12. Furthermore, a return pipe 20 branches off from the water supply pipe 2A downstream of the UF membrane 14, and this return pipe 20 returns the water to the sub-tank 2 via the preheater 10, which serves as its heat source. The return pipe 20 is provided with a pressure control valve 16 as a pressure adjustment mechanism, a pressure sensor 17 as pressure measurement means, and a flowmeter 18 as flow rate measurement means, and this pressure sensor 17 is capable of transmitting information to the control means. The control means is capable of adjusting the aperture of the pressure control valve 16 based on pressure data measured by the pressure sensor 17. Furthermore, the flow meter 18 can transmit information to the control means, and the control means can adjust the amount of primary pure water W fed from the water feed pump 3 and / or the booster pump 8 based on the flow rate data measured by the flow meter 18. In this embodiment, the concentrated water (brine water) from the UF membrane 14 also flows into the return pipe 20.

[0028] (Method for Producing Warm Ultrapure Water) Next, a method for producing warm ultrapure water according to this embodiment using such a warm ultrapure water producing system will be described below.

[0029] In the pretreatment equipment, the raw water is subjected to pretreatment such as filtration, coagulation and sedimentation, and microfiltration membranes, and suspended solids are mainly removed.

[0030] The primary pure water production system includes a reverse osmosis (RO) membrane separation device, a degassing device, a regenerative ion exchange device (mixed-bed type or four-bed five-tower type, etc.), an electrodeionization device, an oxidation device such as an ultraviolet (UV) irradiation oxidation device, etc., and removes most of the electrolytes, fine particles, live bacteria, etc. from the pretreated water. The primary pure water production system is composed of, for example, a heat exchanger, an RO membrane separation device, a mixed-bed ion exchange device, and a degassing device.

[0031] In this embodiment, the primary pure water W produced by this primary pure water production system is treated in the secondary pure water system 1 as follows. After storing the primary pure water W at approximately 25°C in the subtank 2, the water pump 3 supplies it through the water supply pipe 2A and sequentially processes it through the ultraviolet oxidation device 5, the hydrogen peroxide decomposition device 6, and the membrane degassing device 7. The water pressure is then increased by the booster pump 8, and the water is treated in the non-regenerative ion exchange resin tower 9 to produce ultrapure water at approximately 20°C to 30°C. The produced ultrapure water is heated to 30°C to 50°C, e.g., approximately 42°C, by the preheater 10, and subsequently heated to 65°C to 85°C, e.g., approximately 70°C, by the heater 11. The hot ultrapure water W1 is then supplied from the water supply pipe 2A through the UF membrane 14 to the point of use UP. At this time, the flow rate is adjusted by a flow control means (not shown) so that the required amount is supplied to the point of use UP.

[0032] The excess warm ultrapure water W1 then flows through the return pipe 20 and is introduced into the preheater 10 as a heat source fluid, where it exchanges heat with the ultrapure water treated in the non-regenerative ion exchange resin tower 9, lowering its temperature to approximately 40°C, and is then sent to the subtank 2.

[0033] A pressure regulating valve 16 is provided between the return pipe 20 and the preheater 10, immediately after the return pipe 20 branches off from the water supply pipe 2A, and this pressure regulating valve 16 adjusts the opening of the pressure regulating valve 16 so that the pressure measured by the pressure sensor 17 remains approximately constant, thereby maintaining the water supply pressure to the point of use UP at an approximately constant value. In this specification, approximately constant means within ±5%, particularly within ±1%, of the set value.

[0034] Furthermore, steam or hot water (about 5 to 10°C higher than the set temperature of the hot ultrapure water W1) is circulated as a heat source 12 through the heat source fluid flow path of the heater 11 via a flow rate adjustment valve 13. The flow rate adjustment valve 13 is controlled so that the temperature of the hot ultrapure water W1 detected by a temperature sensor 15 provided in the water supply pipe 2A is equal to or higher than the set temperature (e.g., 70°C) and is approximately at the set temperature at the use point UP.

[0035] In this embodiment, a flow meter 18 is provided upstream of the pressure adjustment valve 16 in the return pipe 20, and the amount of water fed by the water feed pump 3 and / or the boost pump 8 is inverter-controlled so that the flow rate measured by this flow meter 18 remains approximately constant, thereby increasing or decreasing the amount of warm ultrapure water W1 produced in response to increases or decreases in the amount of warm ultrapure water W1 used at the point of use UP. This allows the amount of warm ultrapure water W1 produced to be increased or decreased in response to increases or decreases in the amount of warm ultrapure water W1 used at the point of use UP, making it possible to reduce the energy required to produce warm ultrapure water W1 compared to producing a constant amount of warm ultrapure water W1. Note that the lower limit of the fluctuation in the amount of water used at the point of use is preferably 50% or more of the maximum value.

[0036] While the present invention has been described above based on the above embodiment, the present invention is not limited to the above embodiment and can be implemented in various modifications. For example, inverter control of the flow rate of either the water supply pump 3 or the boost pump 8 may be performed by one or both. Furthermore, the heat source 12 of the heater 11 may be heated steam, hot water, or a combination of these. Furthermore, the secondary pure water system 1 is not limited to the configuration of the above embodiment and can be configured with various elements, and depending on the configuration, the boost pump 8 may not be provided.

[0037] The present invention will be described in more detail based on the following specific examples, but the present invention is not limited to the following examples.

[0038] [Comparative Example 1] Using the hot ultrapure water production system shown in FIG. ３Primary pure water W was pumped from a sub-tank 2, which can hold a liquid volume of approximately 1000 kJ / L, via a water pump 3, cooled to 23-25°C in a heat exchanger 4, and treated in an ultraviolet oxidation device 5, a hydrogen peroxide decomposition catalyst tower 6, and a membrane degasser 7. The water pressure was then increased by a boost pump 8 equipped with an inverter downstream of the membrane degasser 7, and the water was treated in a non-regenerative ion exchange resin tower 9 to produce ultrapure water. This ultrapure water was treated in a preheater 10, a heater 11, and a UF membrane 14 to produce hot ultrapure water W1, which was then pumped to the point-of-use UP. 85°C hot water was used as the heat source 12 for the heater 11, and the amount of 85°C hot water supplied was controlled so that the water temperature measured at the temperature sensor 15 was 70°C.

[0039] In such a hot ultrapure water production system, the water pump 3 pumps water at a rate of about 20 m ３ The water quality at the outlet of the UF membrane 14 in this system was a specific resistance of 18.2 MΩ or more and a dissolved oxygen concentration of 1 μg / L or less. The pressure in the return pipe 20 was controlled to 0.2 MPa by the pressure regulating valve 16. The UF membrane 14 was used to measure the brine volume of approximately 2 m ３ The valve was adjusted to be 16 m / h. ３ / h is the maximum water usage amount, and the water volume in the return pipe 20 at this time is about 2 m ３ / h.

[0040] In the manufacturing method of this hot ultrapure water W1, the frequency output from the inverter that controls the rotation speed of the boost pump 8 is set to a constant 48 Hz, and the amount of hot water of about 85°C supplied as a heat medium to the heater 11 is set to about 80 m ３ About / h was required.

[0041] And the amount of water used at the use point UP is 16m ３ / h to about 8m ３ / h, the amount of heat recovered by the preheater 10 increased, but the amount of hot water used as the heat source at 85°C was reduced by 70 m ３ / h.

[0042] [Example 1] In the manufacturing method of Comparative Example 1, the use point UP was set to 16 m, which is the maximum amount of water used. ３ / h, the flow rate in the return pipe 20 is measured by the flow meter 18, and３ The boost pump 8 was inverter controlled so that the frequency was constant at 48 Hz and the hot water supply rate was approximately 80 m ３ Next, the water consumption at the use point UP was 8 m ３ / h, and the flow rate in the return pipe 20 is measured by the flow meter 18. ３ When the boost pump 8 was inverter controlled to keep the frequency constant at 24 to 28 Hz, the amount of hot water used at 85°C, which was the heat source, was about 50 m ３ / h, which enabled a significant reduction in the energy required for supplying and heating the hot ultrapure water W1.

[0043] This method of producing warm ultrapure water increases the amount of water used at the point of use by approximately 8 m per hour. ３ / h and about 16m ３ As a result of repeated operation for 1 hour, the water quality at the outlet of the UF membrane 14 had a resistivity of 18.2 MΩ or more and a dissolved oxygen concentration of 1 μg / L or less, and no effect on the water quality was observed, allowing the maintenance of high-purity water quality.

[0044] REFERENCE SIGNS LIST 1 Secondary pure water device (subsystem) 2 Sub-tank 2A ​​Water supply piping (warm ultrapure water supply line) 3 Water supply pump 8 Booster pump 10 Preheater (first heating means) 11 Heater (second heating means) 12 Heat source 13 Flow rate adjustment valve (flow rate adjustment means) 14 UF membrane 15 Temperature sensor (temperature measurement means) 16 Pressure adjustment valve (pressure adjustment means) 17 Pressure sensor (pressure measurement means) 18 Flow meter (flow rate measurement means) 20 Return piping UP Use point W Primary pure water W1 Warm ultrapure water

Claims

1. A hot ultrapure water production system comprising: an ultrapure water production unit equipped with a primary pure water production apparatus and a secondary pure water production apparatus; a hot ultrapure water supply pipeline for supplying ultrapure water from the ultrapure water production unit to a use point; a first heating means provided in the ultrapure water supply pipeline for supplying heat source water to a heat source fluid flow path via return water in excess of the amount used at the use point; a return pipe for returning the return water that has passed through the heat source fluid flow path of the first heating means to the ultrapure water production unit; and a second heating means for further heating the ultrapure water heated by the first heating means, the ultrapure water heated by the second heating means being supplied to the use point; wherein the return pipe is provided with a flow rate measuring means and a pressure measuring means and a pressure regulating valve downstream of the pressure measuring means, and the hot ultrapure water supply pipeline is provided with a temperature measuring means downstream of the second heating means; A warm ultrapure water manufacturing system having a control means for controlling a pressure regulating valve based on the measurement value of the pressure measuring means, controlling the supply amount of ultrapure water based on the measurement value of the flow rate measuring means, and further controlling a second heating means based on the measurement value of the temperature measuring means.

2. A warm ultrapure water manufacturing system according to claim 1, wherein the secondary pure water manufacturing device has a water pump, and the control means adjusts the supply amount of ultrapure water by controlling the output of the water pump.

3. A warm ultrapure water manufacturing system as described in claim 2, wherein the secondary pure water manufacturing apparatus has a booster pump downstream of the water supply pump, and the control means adjusts the supply amount of ultrapure water by controlling the water supply pump and / or the booster pump.

4. A warm ultrapure water manufacturing system as described in claim 3, wherein the water supply pump and the boost pump are equipped with inverters, the control means controls the frequency output from the inverter, and the lower limit value of the fluctuation value of the water usage amount at the use point is 50% or more of the maximum value.

5. A method for producing warm ultrapure water using a warm ultrapure water production system comprising: an ultrapure water production section equipped with a primary pure water production apparatus and a secondary pure water production apparatus; a warm ultrapure water supply pipe line for supplying ultrapure water from the ultrapure water production section to a use point; a first heating means provided in the ultrapure water supply pipe line for supplying heat source water to a heat source fluid flow path via return water in excess of the amount used at the use point; a return pipe line for returning the return water that has passed through the heat source fluid flow path of the first heating means to the ultrapure water production section; and a second heating means for further heating the ultrapure water heated by the first heating means, the ultrapure water heated by the second heating means being supplied to the use point; the return pipe line being provided with a flow rate measuring means, a pressure measuring means, and a pressure regulating valve downstream of the pressure measuring means; and a temperature measuring means provided downstream of the second heating means in the warm ultrapure water supply pipe line, A method for producing warm ultrapure water, which includes controlling the pressure regulating valve so that the measurement value of the pressure measuring means remains approximately constant, controlling the supply amount of ultrapure water so that the measurement value of the flow rate measuring means remains approximately constant, and further controlling the second heating means so that the measurement value of the temperature measuring means remains constant at a temperature higher than the set temperature of the warm ultrapure water.

6. A method for producing warm ultrapure water according to claim 5, wherein the secondary pure water production apparatus has a water pump, and the control means adjusts the supply amount of ultrapure water by controlling the output of the water pump.

7. A method for producing warm ultrapure water as described in claim 5, wherein the secondary pure water production apparatus has a water supply pump and a booster pump downstream of the water supply pump, and the control means adjusts the supply amount of ultrapure water by controlling the water supply pump and / or the booster pump.

8. A method for producing warm ultrapure water as described in claim 7, wherein the water supply pump and the boost pump are equipped with inverters, the control means controls the frequency output from the inverter, and the lower limit of the fluctuation value of the water usage amount at the use point is 50% or more of the maximum value.

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