JP7112226B2 - Exhaust heat recovery and reuse system for water treatment equipment in semiconductor manufacturing equipment - Google Patents

Description

The present invention relates to an exhaust heat recovery and reuse system for water treatment equipment in semiconductor manufacturing facilities, and more particularly to an exhaust heat recovery and reuse system using a heat pump.

A waste heat utilization system using a heat pump is known. Patent Documents 1 and 2 disclose a feed water heating system equipped with a heat pump that absorbs heat from waste hot water in a factory and heats the feed water of a boiler.

JP 2017-96569 A JP 2017-96570 A

2. Description of the Related Art Among semiconductor manufacturing facilities, fluids that require heating are distributed in water treatment facilities such as pure water and ultrapure water production facilities and wastewater treatment facilities. Some of these fluids require heating to 40-50°C. In order to heat the fluid at this temperature, heat exchange between the fluid and a high-temperature fluid such as steam or drain is required. For this reason, a water treatment facility in a conventional semiconductor manufacturing facility is provided with a utility facility for supplying steam and hot water. On the other hand, water treatment equipment in semiconductor manufacturing facilities circulates various fluids, such as warm waste water generated by exhaust gas detoxification treatment (detoxification), and hot water generated by pure water and ultrapure water production equipment. there is Conventionally, the thermal energy possessed by these warm wastewaters has not been effectively utilized.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust heat recovery and reuse system capable of effectively utilizing thermal energy in a water treatment facility in a semiconductor manufacturing facility.

An exhaust heat recovery and reuse system for water treatment equipment in a semiconductor manufacturing facility according to the present invention includes an evaporator that evaporates a refrigerant, a compressor that compresses the refrigerant, a condenser that condenses the refrigerant, and an expansion valve that expands the refrigerant. It has heat pumps arranged on the closed-loop piping in that order. The evaporator absorbs heat from the first fluid that constantly flows through the water treatment equipment in the semiconductor manufacturing facility, and the second fluid that flows irregularly or intermittently in the water treatment equipment is heated by the heat discharged from the condenser. The water treatment facility has a pure water supply facility that supplies pure water or ultrapure water to the semiconductor manufacturing facility, the pure water supply facility has a resin tower for purifying the raw water, and the second fluid is the resin tower. It is fed to the resin tower for regeneration. The exhaust heat recovery and reuse system further includes a heat storage unit that stores heat discharged from the condenser and heats the second fluid with the stored heat. The heat storage unit is a container for storing intermediate circulating water, and is composed of a first water chamber located at one end of the container and an Nth water chamber (N is 2 or more) located at the other end of the container. a container having N−1 partition walls dividing the container into N water chambers containing at least natural numbers), and allowing intermediate circulating water to flow between adjacent water chambers; a first intermediate loop pipe extending between the lower part of the water chamber and the upper part of the first water chamber and having a heat exchange part with the condenser in the middle; and a second intermediate loop pipe extending between and having a heat exchange section with a second fluid along the way.

According to the present invention, the heat energy possessed by the first fluid can be recovered by the heat pump to heat the second fluid. Since the first fluid constantly flows through the water treatment equipment in the semiconductor manufacturing equipment, it can be used as a stable heat source. Therefore, according to the present invention, it is possible to provide an exhaust heat recovery and reuse system capable of effectively utilizing thermal energy in a water treatment facility in a semiconductor manufacturing facility.

1 is a schematic diagram showing the overall configuration of an exhaust heat recovery and reuse system according to an embodiment of the present invention; It is a schematic diagram showing the overall configuration of a modification of the exhaust heat recovery and reuse system. 1 is a schematic diagram showing the configuration of part of a water treatment facility in a semiconductor manufacturing facility to which an exhaust heat recovery and reuse system according to one embodiment of the present invention is applied;

Hereinafter, an exhaust heat recovery and reuse system for water treatment equipment in semiconductor manufacturing equipment according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of an exhaust heat recovery and reuse system according to one embodiment of the present invention. In the following description, the “first fluid” is fluid that constantly flows inside the water treatment facility 100 in the semiconductor manufacturing facility 101 and absorbs heat from the evaporator 2 b of the heat pump 2 . That is, the first fluid is a fluid that serves as a heat source. A pipe through which the first fluid flows is called a first pipe L1. A portion where the first fluid exchanges heat with the evaporator 2b of the heat pump 2, that is, a portion where heat is absorbed by the heat pump 2 is referred to as a first heat exchange portion H1. The “second fluid” is a heated fluid that flows through the water treatment facility 100 and is heated by the heat discharged from the condenser 2 d of the heat pump 2 . A pipe through which the second fluid flows is called a second pipe L2. A portion where the second fluid exchanges heat with the condenser 2d of the heat pump 2 via the intermediate circulating water, that is, a portion heated by the heat pump 2 via the intermediate circulating water is called a second heat exchange portion H2. The "second fluid" may be a fluid that always flows through the water treatment facility 100, or may be a fluid that flows unsteadily or intermittently. Also, although the first and second fluids are water in the following embodiments, they may be liquids other than water or gases.

In the following embodiments, the first fluid is one type of fluid that flows through a specific line in the water treatment facility 100, but it may be multiple types of fluid that flow through different lines. Similarly, the second fluid is one type of fluid that flows through a particular line in the water treatment plant 100, but may be multiple types of fluid that flow through different lines.

The first fluid is stored in the receiving tank 5 and supplied to the exhaust heat recovery and reuse system 1 of the water treatment facility 100 through the first pipe L1 equipped with the pump 7 . A third pipe L3 equipped with a pump 8 branches off from the first pipe L1, and part of the first fluid bypasses the exhaust heat recovery and reuse system 1 and is sent to the post-stage equipment 9 by the pump 8. .

The exhaust heat recovery and reuse system 1 of the water treatment facility 100 has a heat pump 2 . The heat pump 2 has an evaporator 2b that evaporates the refrigerant flowing through the closed loop pipe 2a, a compressor 2c that compresses the refrigerant, a condenser 2d that condenses the refrigerant, and an expansion valve 2e that expands the refrigerant. They are arranged in order on the closed loop pipe 2a.

A pump 3 and a heat pump 2 located downstream thereof are provided in the first pipe L1. The first fluid flowing through the first pipe L1 exchanges heat (absorbs heat) with the evaporator 2b of the heat pump 2 in the first heat exchange section H1. The refrigerant circulating in the heat pump 2 absorbs heat from the first fluid and evaporates (supplied with latent heat). The temperature of the first fluid is lowered by heat exchange with the evaporator 2b. This effectively utilizes the thermal energy of the first fluid. In addition, the heat exchange lowers the temperature of the first fluid, so that the temperature of the first fluid supplied to the post-stage equipment 9 becomes a temperature suitable for the performance of the post-stage equipment.

A three-way valve 4 is provided downstream of the pump 3 in the first pipe L1. A reflux pipe LR branches off from the first pipe L1 downstream of the first heat exchange section H1 of the first pipe L1 and joins the first pipe L1 at the three-way valve 4 . The performance of the heat pump 2 depends on the temperature of the first fluid heat-exchanged in the evaporator 2b, and if the temperature of the first fluid is too high, desired performance may not be obtained. In that case, the three-way valve 4 is switched so that part of the first fluid whose temperature has been lowered by heat exchange with the evaporator 2b is returned to the upstream side of the evaporator 2b of the heat pump 2 . As a result, the temperature of the first fluid supplied to the first heat exchange section H1 can be adjusted to a temperature that is preferable for the performance of the heat pump 2 . Also, the three-way valve 4 can control and adjust the temperature of the first fluid cooled by the heat pump 2 to the temperature required by the post-stage equipment 9 . In a general heat pump, heat exchange is performed in one pass, that is, without recirculation, but due to the characteristics of the heat pump, the temperature difference between the inlet temperature and the outlet temperature of the heat pump is about 3 to 10 degrees Celsius. limit. When it is necessary to secure a temperature difference exceeding this, temperature adjustment is generally performed using an intermediate tank, a heat exchanger, and a three-way valve or a control valve as ancillary equipment. In the present embodiment, since the three-way valve 4 recirculates the first fluid, the temperature control range of the first fluid is widened, and incidental equipment can be simplified. By installing a thermometer T1 in the first pipe L1 and adjusting the three-way valve 4 based on the measurement result of the thermometer T1, the ratio of recirculating (refluxing) the first fluid can be appropriately controlled. can be done. The thermometer T1 may be installed at the entrance or the exit of the heat exchange section H1. If the return pipe LR is unnecessary due to the relationship between the temperature of the first fluid and the performance of the heat pump 2, the return pipe LR and the three-way valve 4 can be omitted.

The exhaust heat recovery and reuse system 1 has a heat storage section 6 provided between the condenser 2d of the heat pump 2 and the second heat exchange section H2. The heat storage unit 6 stores the heat radiated from the condenser 2d, and heats the second fluid with the stored heat. The heat storage unit 6 has a container 6a that stores intermediate circulating water. The container 6a has two partition walls 6b, 6c which divide the interior of the container 6a into first, second and third water chambers 61, 62, 63. As shown in FIG. The number of water chambers is not limited to three, and the container 6a generally includes N (N is a natural number of 2 or more) water chambers arranged in series, and the interior of the container 6a is divided into these water chambers. It has N-1 dividing walls. Of the N water chambers, the water chamber located at one end of the container 6a is called the first water chamber 61, and the water chamber located at the other end of the container 6a is called the Nth water chamber (this In the embodiment, this is referred to as a third water chamber 63). The lower ends of the partition walls 6b, 6c are separated from the bottom of the container 6a, and the upper ends of the partition walls 6b, 6c are above the water level of the intermediate circulating water. Therefore, the intermediate circulating water can flow between adjacent water chambers through the gaps between the lower ends of the partition walls 6b and 6c and the bottom of the container 6a.

FIG. 2 shows a modification of the heat storage section 6. As shown in FIG. In the modification shown in FIG. 2(a), the lower end of the partition wall 6b is separated from the bottom of the container 6a, and the upper end is above the water level of the intermediate circulating water. On the other hand, the lower end of the partition wall 6c is connected to the bottom of the container 6a and the upper end is below the level of the intermediate circulating water. In the modification shown in FIG. 2(b), the lower end of the partition wall 6b is connected to the bottom of the container 6a, and the upper end is below the water level of the intermediate circulating water. On the other hand, the lower end of the partition wall 6c is separated from the bottom of the container 6a, and the upper end is above the water level of the intermediate circulating water. In any modification, the intermediate circulating water can flow between adjacent water chambers through gaps. Since low-temperature intermediate circulating water is easily taken out from the first intermediate loop pipe LM1 and high-temperature intermediate circulating water is easily taken out from the second intermediate loop pipe LM2, the heat exchange efficiency is enhanced. In particular, in the configuration shown in FIG. 2A, the low-temperature intermediate circulating water stays in the vicinity of the outlet of the first intermediate loop pipe LM1 of the container 6a due to the difference in the specific gravity of the water. Efficient and easy to remove. When three or more partition walls are provided, there is a partition wall whose lower end is spaced from the bottom of the container 6a and whose upper end is above the water level of the intermediate circulating water, and whose lower end is connected to the bottom of the container 6a and whose upper end is the water level of the intermediate circulating water. can be alternated with the partition wall below.

A first intermediate loop pipe LM1 extends between the upper portion of the first water chamber 61 and the lower portion of the third water chamber 63 . An intermediate heat exchange section HM that exchanges heat (releases latent heat of the refrigerant) with the condenser 2d is provided in the middle of the first intermediate loop pipe LM1. A first intermediate pump P1 is provided upstream of the intermediate heat exchange section HM of the first intermediate loop pipe LM1. A second intermediate loop pipe LM2 extends between the lower portion of the first water chamber 61 and the upper portion of the third water chamber 63 . A second heat exchange section H2 that exchanges heat with a second fluid is provided in the middle of the second intermediate loop pipe LM2. A second intermediate pump P2 is provided upstream of the second heat exchange section H2 of the second intermediate loop pipe LM2.

The exhaust heat recovery and reuse system 1 operates as follows to impart the thermal energy of the first fluid to the second fluid. As described above, the first fluid normally flows through the first pipe L1. The heat pump 2 is always operated. The first intermediate pump P1 is in normal operation. Therefore, intermediate circulating water normally flows through the first intermediate loop pipe LM1. The heat pump 2 deprives the first fluid of heat energy in the first heat exchange section H1 and heats the intermediate circulating water in the intermediate heat exchange section HM. The heated intermediate circulating water flows into the first water chamber 61 from the upper portion of the first water chamber 61 . The intermediate circulating water flows from the first water chamber 61 into the second water chamber 62 through the gap between the lower ends of the partition walls 6b and 6c and the bottom of the container 6a, and then into the third water chamber 63. influx. The intermediate circulating water that has flowed into the third water chamber 63 is drawn out from the lower portion of the third water chamber 63, pressurized by the first intermediate pump P1, and heated again in the intermediate heat exchange section HM. In this manner, the heat exchanged with the evaporator 2b is accumulated in the heat storage unit 6. As shown in FIG. A second intermediate pump P2 is activated when heating the second fluid. The intermediate circulating water flows into the second intermediate loop pipe LM2 from the lower portion of the first water chamber 61, is pressurized by the second intermediate pump P2, and flows through the second pipe L2 in the second heat exchange section H2. Exchanging heat with the second fluid (heating the second fluid).

When only the first intermediate pump P1 is activated, intermediate circulating water flows from the first water chamber 61 to the third water chamber 63 in the container 6a. Therefore, the intermediate circulating water in the first water chamber 61 has the highest temperature, and the intermediate circulating water in the third water chamber 63 has the lowest temperature. When the second pump P2 is started in this state, the intermediate circulating water is supplied from the first water chamber 61, which has the highest temperature, to the second heat exchanging part H2. Can be heated.

Although the heat pump 2 is constantly operated in the above-described embodiment, the heat pump 2 can be intermittently operated according to the amount of heat required by the second fluid. For example, when the heating capacity of the heat pump 2 is 120 kW and the required amount of heat of the second fluid is 900 kWh, the heat pump 2 can be operated for about 8 hours per day, ignoring the heat radiation loss of the heat storage unit 6 and the like. Also, a plurality of heat pumps 2 can be installed in parallel according to the required amount of heat of the second fluid.

Although heat exchange is performed between one type of first fluid and one type of second fluid in the above-described embodiments, heat exchange is performed between one type of first fluid and a plurality of second fluids. The exchange may take place, the heat exchange may take place between a plurality of first fluids and one type of second fluid, or the plurality of first fluids and a plurality of second fluids may be exchanged. heat exchange may take place between When the heat pump 2 absorbs heat from a plurality of first fluids, a plurality of first heat exchange units H1 can be arranged in series along the evaporator 2b of the heat pump 2 . When a plurality of second fluids are heated by the heat pump 2, a plurality of second heat exchange units H2 can be arranged in series or parallel along the condenser 2d of the heat pump 2.

FIG. 3 is a schematic diagram showing a partial configuration of a water treatment facility 100 in a semiconductor manufacturing facility 101 to which the exhaust heat recovery and reuse system 1 according to one embodiment of the present invention is applied. Specific examples of the first fluid (first pipe L1) and the second fluid (second pipe L2) will be described below.

The water treatment facility 100 has a pure water supply facility 11 that supplies pure water or ultrapure water used for cleaning wafers and the like. In the present invention, the pure water supply facility 11 is a concept including an ultrapure water supply device, and the pure water supply facility 11 of the present embodiment is used in the sense of an ultrapure water supply facility. The pure water supply facility 11 is supplied with waste water treated by a detoxification device 121, which will be described later, as well as external industrial water (collectively referred to as raw water). Particles and microparticles are removed from the raw water supplied to the pure water supply facility 11 by the filter 111 . The raw water is then purified by removing impurities other than water such as ions and salts in a reverse osmosis membrane device (RO) 112 . The raw water is further UV sterilized by the UV sterilizer 113 and purified by further removing ion components in the resin tower 114 to produce pure water. Pure water is stored in a primary pure water tank 115 . Each device from the raw water supply unit to the primary pure water tank 115 is arranged in series on the first line L11.

The primary pure water tank 115 is connected to a warm ultrapure water supply line L12 and a normal temperature ultrapure water supply line L13. This is because hot ultrapure water or normal temperature ultrapure water is required depending on the point of use. Hereinafter, the point of use of the semiconductor manufacturing facility 101 requiring warm ultrapure water is referred to as the warm ultrapure water point of use UP1, and the point of use of the semiconductor manufacturing facility 101 requiring room temperature ultrapure water is referred to as the normal temperature ultrapure water point of use UP2. The pure water passing through the hot ultrapure water supply line L12 and the normal temperature ultrapure water supply line L13 are both UV sterilized by UV oxidizers 116a and 116b, and ionized by cartridge polishers (non-regenerative mixed-bed ion exchangers) 117a and 117b. The components are further removed, and ultrafiltration membranes (UF) 119a and 119b remove microparticles containing viable bacteria to produce ultrapure water. A pure water heater (heat exchanger) 118 is provided downstream of the cartridge polisher 117a. Therefore, the ultrafiltration membrane device 119a is provided between the heating device 118 and the warm ultrapure water use point UP1, and the ultrafiltration membrane device 119b is provided between the cartridge polisher 117b and the normal temperature ultrapure water use point UP2. The permeated water of the ultrafiltration membrane 119a is sent as warm ultrapure water to each warm ultrapure water use point UP1, and the permeated water of the ultrafiltration membrane 119b is sent as room temperature ultrapure water to each room temperature ultrapure water use point UP2. In this way, the devices from the primary pure water tank 115 to the warm ultrapure water use point UP1 are arranged in series on the warm ultrapure water supply line L12, and the devices from the primary pure water tank 115 to the normal temperature ultrapure water use point UP2 are arranged in series. The devices are arranged in series on the room-temperature ultrapure water supply line L13.

The warm ultrapure water not used at the warm ultrapure water use point UP1 is sent to the primary pure water tank 115 as first return water through the first return line L14 for reuse. The first return line L14 extends from the most downstream warm ultrapure water use point UP1 to the primary pure water tank 115, but the first return water may be returned to the upstream of the heating device 118 at least. This is because the first return water is used as a heat source for the heat pump 2 and cooled to a temperature that requires heating by the heating device 118, as will be described later. Room-temperature ultra-pure water not used at the normal-temperature ultra-pure water use point UP2 is also reused, so it passes through the second return line L15 and is sent to the primary pure water tank 115 as second return water.

The non-permeated water (reject water) of the ultrafiltration membrane device 119a of the warm ultrapure water supply line L12 is also reused, so it passes through the third return line L16 and is sent to the primary pure water tank 115 as the first UF reject water. be done. The third return line L16 extends from the permeated side of the warm ultrapure water to the primary pure water tank 115, but the third return water may be returned to the upstream of the heating device 118 at least. This is because the third return water is used as a heat source for the heat pump 2 and cooled to a temperature that requires heating by the heating device 118, as will be described later. The non-permeated water (reject water) of the ultrafiltration membrane device 119b of the normal temperature ultrapure water supply line L13 is also reused, so it passes through the fourth return line L17 and flows into the primary pure water tank 115 as the second UF reject water. sent to

The first fluid in the pure water supply facility 11, that is, the heat source of the second fluid is the pure water or ultrapure water flowing through the first return line L14 as described above, or the pure water flowing through the third return line L16. This is non-permeate water (first UF reject water) of the outer filtration membrane device 119a. The temperature of these fluids is 30° C. or higher and 40° C. or lower, which is suitable as the temperature of the heat source.

The water treatment facility 100 has a wastewater recovery facility 12 . In the semiconductor manufacturing equipment 101, various harmful gases having toxicity and corrosiveness are generated as exhaust gas. These exhaust gases are discharged out of the system after undergoing a treatment to remove (detoxify) harmful components. For the purpose of removing harmful components in the exhaust gas, for example, a combustion type removal device 121 is used. In the combustion type detoxification device 121, the exhaust gas introduced into the combustion cylinder is combusted or thermally decomposed by the burner, thereby detoxifying harmful components in the exhaust gas. Since exhaust gas that has been burned at high temperature is cooled by cooling water, waste water with a relatively high temperature is generated in the process. The turbidity components are removed from this waste water by the turbidity removal membrane 122 , particles and fine particles are further removed by the reverse osmosis membrane device 123 , and the waste water is stored in the make-up water tank 124 . The make-up water tank 124 is also replenished with make-up water from the outside. The water stored in the make-up water tank 124 is reused by the abatement device 121 . In the present embodiment, relatively hot waste water from the abatement facility is used as the first fluid. The first fluid is desirably the fluid that flows in the preceding stage of the reverse osmosis membrane device 123 , that is, the section between the turbidity removal membrane 122 and the reverse osmosis membrane device 123 . This is because the reverse osmosis membrane device 123 is desirably supplied with warm water of 5 to 30° C., more preferably 20 to 30° C., in order to obtain good particulate removal performance. Since the water discharged from the abatement device 121 has a relatively high temperature, the temperature of the discharged water can be lowered to a temperature preferable for the operation of the reverse osmosis membrane device 123 by removing heat on the upstream side of the reverse osmosis membrane device 123. can. The discharged water from the abatement device 121 has a large amount of discharge, and generally has a temperature of about 33 to 40° C., and is one of the discharged water with the largest heat quantity among the discharged water discharged from the water treatment facility 100 . In addition, this waste water is basically discharged in a stable amount 24 hours a day.

The water treatment facility 100 has a waste water treatment facility 13 . Wastewater discharged from various machines of the water treatment facility 100 undergoes evaporation treatment in the wastewater evaporation device 131, distillation treatment in the wastewater distillation device 132, coagulation sedimentation treatment in the coagulation sedimentation device 133, and the like. Further, organic contaminants in the waste water are decomposed and removed in the biological treatment device 134 using microbial activity, and finally treated in the final treatment device 135 and discharged out of the system. The final treatment device 135 is composed of, for example, one or a combination of a coagulation pressurized flotation separation device, a filter, an activated carbon tower/ph adjustment device, and the like. At least one of the waste water evaporation device 131 and the waste water distillation device 132 may be provided. The temperature of the discharged water is usually 30° C. or higher and 40° C. or lower, which is preferable as the temperature for heating the second fluid. In addition, since the discharged water is constantly flowing, it can be used as a stable heat source. Therefore, the discharged water discharged from the water treatment facility 100 is used as the first fluid.

In the semiconductor manufacturing equipment 101, heat is removed from a clean room or the like by an air conditioner, and the removed heat is released outside the system. Specifically, the heat removed by the air conditioner is transferred to the cooling water flowing through the intermediate loop 141 , and the cooling water is cooled by the cooling tower 142 . The intermediate loop 141 is provided with a cooling tower 142, a filter 143 for filtering cooling water, and a make-up water tank 144 for storing filtered cooling water, so that the cooling water is circulated. The make-up water tank 144 is also replenished with make-up water from the outside. The temperature of the cooling water in the downstream section of the cooling tower 142 is usually 30 to 40° C., which is a preferable temperature as a heat source. Therefore, the outlet water of the cooling tower 142, preferably the outlet water of the filter 143, is used as the first fluid.

The heated fluid in the water treatment facility 100, ie, the second fluid, includes the following. First, the second fluid is water (regenerated water) supplied to the resin tower 114 to regenerate the resin tower 114 . The temperature of the reclaimed water is desirably 40°C or higher and 50°C or lower. The regeneration treatment of the resin tower 114 is periodically performed, for example, once a day, but the regeneration water is required only at this timing.

Another second fluid is the inlet water of the reverse osmosis membrane device 112 . As described above, the reverse osmosis membrane device 112 is desirably supplied with warm water of 5 to 30° C., more preferably 20 to 30° C., in order to obtain good particulate removal performance. Therefore, when the temperature of the inlet water of the reverse osmosis membrane device 112 is below this, it is possible to heat the inlet water of the reverse osmosis membrane device 112, more preferably the inlet water of the filter 111 with hot water stored in the heat storage unit 6. desirable.

Still another second fluid includes feed water supplied to at least one of the waste water evaporation device 131 and the waste water distillation device 132 of the waste water treatment facility 13 . The feed water is heated to a temperature suitable for evaporating or distilling the waste water from the machine, but by preheating the feed water with hot water stored in the heat store 6, energy for the heating can be saved.

As described above, in this embodiment, heat exchange is performed between the plurality of first fluids and the plurality of second fluids. Therefore, the temperature of the intermediate circulating water stored in the heat storage unit 6 can be set according to the highest temperature required as the second fluid or the temperature of the second fluid required in the largest amount. preferable. In this embodiment, heat is absorbed mainly from hot water of 30 to 40° C. discharged from the abatement device 121, and the heat is supplied to the heat unit 6, mainly as reclaimed water (required temperature 40 to 50° C.) of the resin tower 114. used. Therefore, the heat pump 2 raises the temperature of the intermediate circulating water to about 55°C. Therefore, it is desirable to provide temperature control means, for example, to heat the inlet water of the reverse osmosis membrane device 112 to a range of 20-30°C. A flow control valve 7 provided in the second intermediate loop pipe LM2 can be used as the temperature control means. By narrowing the opening of the flow control valve 7, the flow rate of the intermediate circulating water flowing through the second intermediate loop pipe LM2 can be suppressed, and the temperature of the inlet water of the reverse osmosis membrane device 112 can be prevented from rising excessively. . At this time, a thermometer for measuring the temperature of the inlet water of the reverse osmosis membrane device 112 can be provided, and the degree of opening of the flow control valve 7 can be adjusted according to the measured temperature. In addition, since the reflux pipe LR and the three-way valve 4 can adjust the temperature and flow rate of the first fluid supplied to the first heat exchange section H1, the temperature of the second fluid can be adjusted to 40° C. or more and 50° C. or less. It functions as a temperature control means for heating to the range of

As described above, according to the present embodiment, the thermal energy of the first fluid can be effectively used to reduce the thermal energy required for heating the second fluid. The total amount of energy required can be reduced. The heat pump 2 can dissipate a quantity of heat equal to the sum of the heat energy absorbed from the first fluid and the work of the compressor 2c. can do. Ignoring heat radiation loss and heat transfer loss, the energy that can be reduced is the value obtained by subtracting the driving power of the heat pump 2 from the energy generated by the heat pump 2 (the sum of the amount of heat absorbed by the heat pump 2 and the work of the compressor 2c). / year.

Also, when cooling the effluent discharged to the outside of the system, the cooling load can be reduced by removing heat from the effluent, and the capacity of the cooling equipment and the amount of cooling water can be reduced.

Furthermore, since the exhaust heat recovery and reuse system 1 of the present embodiment has the heat storage section 6, the exhaust heat recovery and reuse system 1 can be configured more rationally. When the exhaust heat of the first fluid is directly transferred to the second fluid, it is necessary to provide the heat pump 2 with a capacity capable of covering the required thermal energy of the second fluid. However, since heating of the second fluid is basically performed intermittently, the capacity of the heat pump 2 can be suppressed by providing the heat storage unit 6 .

1 Exhaust heat recovery and reuse system 2b Evaporator 2c Compressor 2d Condenser 2e Expansion valve 2a Closed loop piping 2 Heat pump 6 Heat storage unit 6a Container 6b, 6c Partition wall 61-63 First to third water chambers 11 Pure water supply equipment 12 Drainage Recovery equipment 13 Wastewater treatment equipment 100 Water treatment equipment in semiconductor manufacturing equipment 101 Semiconductor manufacturing equipment 113 Reverse osmosis membrane device 114 Resin tower 118 Heating device 119a, 119b Ultrafiltration membrane device 121 Harm removal equipment 131 Waste water evaporation device 132 Waste water distillation device 142 Cooling tower H1 First heat exchange section H2 Second heat exchange section HM Intermediate heat exchange section L1 First pipe L2 Second pipe L14 First return line LM1 First intermediate loop pipe LM2 Second intermediate loop Pipe LR Reflux pipe UP1 Hot ultrapure water use point UP2 Room temperature ultrapure water use point

Claims (7)

A heat pump in which an evaporator that evaporates a refrigerant, a compressor that compresses the refrigerant, a condenser that condenses the refrigerant, and an expansion valve that expands the refrigerant are arranged in this order on a closed loop pipe,
The evaporator absorbs heat from the first fluid that constantly flows through the water treatment equipment in the semiconductor manufacturing facility, and the second fluid that flows irregularly or intermittently in the water treatment equipment is heated by the heat discharged from the condenser. is,
The water treatment facility has a pure water supply facility for supplying pure water or ultrapure water to the semiconductor manufacturing facility, the pure water supply facility has a resin tower for purifying raw water, and the second fluid is , supplied to said resin tower to regenerate said resin tower;
further comprising a heat storage unit that stores heat discharged from the condenser and heats the second fluid with the stored heat;
The heat storage unit is
A container for storing intermediate circulating water, comprising a first water chamber positioned at one end of the container and an Nth water chamber positioned at the other end of the container (N is a natural number of 2 or more) a container having N−1 partition walls dividing the container into N water chambers containing at least a and allowing the intermediate circulating water to flow between the adjacent water chambers;
a first intermediate loop pipe extending between the lower portion of the Nth water chamber and the upper portion of the first water chamber and having a heat exchange section with the condenser along the way;
a second intermediate loop pipe extending between the lower portion of the first water chamber and the upper portion of the Nth water chamber and having a heat exchange section with the second fluid along the way;
An exhaust heat recovery and reuse system for water treatment equipment in a semiconductor manufacturing facility. 2. The exhaust heat recovery and reuse system according to claim 1, further comprising temperature control means for heating the second fluid to a range of 40[deg.] C. or more and 50[deg.] C. or less. 3. The exhaust heat recovery and reuse system according to claim 1, wherein said first fluid is waste water from a gas abatement facility provided in said water treatment facility. 3. The exhaust heat recovery and reuse system according to claim 1, wherein said first fluid is discharged water discharged outside from said water treatment facility. The pure water supply equipment includes a pure water or ultrapure water heating device, an ultrafiltration membrane device provided between the heating device and a use point of the semiconductor manufacturing facility, and the ultrafiltration membrane device and the ultrafiltration membrane device. a pipe connecting a point of use and a return line branching from the pipe and returning pure water or ultrapure water not used at the point of use to the upstream of the heating device;
3. The exhaust heat recovery and reuse system according to claim 1, wherein said first fluid is non-permeated water of said ultrafiltration membrane device, or pure water or ultrapure water flowing through said return line. 3. The exhaust heat recovery and reuse system according to claim 1, wherein said first fluid is outlet water of a cooling tower of an air conditioner of said semiconductor manufacturing facility. The exhaust heat recovery and reuse system according to any one of claims 1 to 6 , wherein the first fluid has a temperature of 30°C or higher and 40°C or lower.

Images