Waste heat recovery system

Abstract

This system enhances energy conservation by recovering waste heat from the cooling water of refrigeration units, while simultaneously linking and integrating the hot water system for air conditioning with the cooling water system for refrigeration units. [Solution] The hot water system 20 for air conditioning is equipped with a hot water supply side temperature sensor 31 which also serves as a temperature setting unit. The device cooling water system 23 uses the waste heat from the device cooling water of the device cooling water system 23 to raise the temperature of the hot water in the air conditioning hot water system 20 via the first heat exchanger 21. The chiller cooling water system 25 reheats the hot water in the air conditioning hot water system 20 via the second heat exchanger 24. The temperature setting unit of the hot water supply side temperature sensor 31 is configured to set the temperature of the hot water in the air conditioning hot water system 20 via the first heat exchanger 21 and the second heat exchanger 24, and also to set the temperature of the chiller cooling water in the chiller cooling water system 25.

Description

Technical Field

[0001] The present invention relates to a waste heat recovery system.

Background Art

[0002] An industrial clean room needs to maintain a positive pressure inside to prevent the intrusion of dust, and it is also necessary to supply air from the outside corresponding to various exhaust volumes generated by each device in the production process. Therefore, as shown in FIG. 14, outside air is taken in from the outside conditioner 1 and supplied into the clean room.

[0003] The outside conditioner 1 is provided with a preheating coil 2, a humidifier 3, a reheating coil 4, a blower (not shown), a HEPA filter (not shown), etc. in order from the upstream side, heating and humidifying the outside air and supplying it to the clean room.

[0004] The preheating coil 2 and the reheating coil 4 of the outside conditioner 1 are connected to the air-conditioning hot water system 5, and the air-conditioning hot water system 5 is a circulation line 7 provided with a hot water pump 6 for circulating hot water. The circulation line 7 is provided with a refrigerator cooling water system 9 disposed via a heat exchanger 8, and recovers waste heat from the refrigerator 10.

[0005] The refrigerator cooling water system 9 includes a refrigerator-side circulation line 11 for circulating cooling water to the refrigerator 10 via the heat exchanger 8, and a bypass line 12 connected to the refrigerator-side circulation line 11 so as not to pass through the heat exchanger 8. The refrigerator-side circulation line 11 is provided with a cooling tower 13 and a pump 14 on the cooling water supply side to the refrigerator 10, and a return line 15 for returning the cooling water from the refrigerator 10 to the cooling tower 13 instead of the heat exchanger 8.

[0006] A supply-side two-way valve 16 is provided on the outlet side of the heat exchanger 8 of the refrigerator-side circulation line 11, and a bypass-side two-way valve 17 is provided on the bypass line 12, and the flow rates of the refrigerator-side circulation line 11 and the bypass line 12 are controlled according to the temperature of the air-conditioning hot water system 5. Further, a return-side two-way valve (flow control valve) 18 is provided on the return line 15.

[0007] As a result, the hot water system 5 for air conditioning recovers waste heat from the chiller cooling water and simultaneously raises the temperature of the hot water returning from the preheating coil 2 and reheating coil 4 before supplying it back to the preheating coil 2 and reheating coil 4.

[0008] Prior art documents related to this type of air handling unit and cleanroom include Patent Document 1 below, and prior art documents related to heat exchangers include Patent Document 2 below. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2005-61647 [Patent Document 2] Japanese Patent Publication No. 2009-281642 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, when obtaining the necessary temperature of hot water for air conditioning the cleanroom using the hot water system 5 for air conditioning, the temperature of the chiller cooling water must be fixed at a high set temperature. On the other hand, if the temperature of the chiller cooling water in the chiller cooling water system 9 is high, the chiller 10 cannot be operated in the high-efficiency range, which presents a problem in that the energy-saving effect of recovering waste heat from the chiller cooling water cannot be utilized.

[0011] Furthermore, since the air conditioning hot water system 5 and the chiller cooling water system 9 operate independently, there was a problem in that it was difficult to link or synchronize the air conditioning hot water system 5 and the chiller cooling water system 9.

[0012] In view of these circumstances, the present invention aims to provide a waste heat recovery system that enhances the energy-saving effect of recovering waste heat from the cooling water of a chiller, while simultaneously linking and coordinating the hot water system for air conditioning and the cooling water system for a chiller. [Means for solving the problem]

[0013] The present invention comprises an air conditioning hot water system that supplies hot water to an air conditioner that heats the outside air, a production equipment cooling water system that is arranged on the return side of the hot water of the air conditioning hot water system via a first heat exchanger, and a chiller cooling water system that is arranged on the supply side of the hot water of the air conditioning hot water system via a second heat exchanger. The aforementioned hot water system for air conditioning includes a hot water circulation line that circulates hot water to the air conditioner, and a hot water supply side temperature sensor that is positioned in the hot water circulation line between the second heat exchanger and the air conditioner and also serves as a temperature setting unit. The aforementioned device cooling water system comprises a device circulation line that circulates device cooling water to the production equipment via a first heat exchanger, a first bypass line connected to the device circulation line so as not to pass through the first heat exchanger, and a cooling water supply side temperature sensor located on the supply side of the device circulation line. The system controls the flow rate of device cooling water in the device circulation line and the first bypass line according to the temperature detected by the cooling water supply side temperature sensor, thereby adjusting the temperature of the device cooling water returned to the production equipment. Furthermore, the waste heat from the device cooling water in the device cooling water system is used to raise the temperature of the hot water in the air conditioning hot water system via the first heat exchanger. The aforementioned chiller cooling water system includes a chiller circulation line that circulates chiller cooling water to the chiller via a second heat exchanger, and a second bypass line that is connected to the chiller circulation line without passing through the second heat exchanger. The flow rate of chiller cooling water in the chiller circulation line and the second bypass line is controlled according to the temperature detected by the hot water supply side temperature sensor, and the hot water in the air conditioning hot water system is reheated via the second heat exchanger. The temperature setting unit of the hot water supply side temperature sensor is configured to set the temperature of the hot water in the air conditioning hot water system via the first heat exchanger and the second heat exchanger, as well as to set the temperature of the chiller cooling water in the chiller cooling water system. This relates to a waste heat recovery system characterized by the following features.

[0014] In the waste heat recovery system of the present invention, the hot water system for air conditioning includes a hot water return side temperature sensor positioned in the hot water circulation line between the air conditioner and the first heat exchanger. The device cooling water system may be configured to flow the entire amount of device cooling water into the first bypass line according to the temperature detected by the hot water return side temperature sensor, thereby preventing the device cooling water from rising in temperature due to heat exchange with the hot water in the air conditioning hot water system.

[0015] In the waste heat recovery system of the present invention, the chiller cooling water system includes a chiller outlet side temperature sensor positioned in the chiller circulation line between the chiller and the second heat exchanger. The temperature setting unit of the hot water supply side temperature sensor sets the chiller outlet temperature of the chiller outlet side temperature sensor in conjunction with the hot water temperature setting of the air conditioning hot water system. The aforementioned chiller cooling water system may be configured to flow the entire amount of chiller cooling water to a second bypass line according to the temperature detected by the chiller outlet side temperature sensor, in order to address cases where the chiller cooling water cannot exchange heat with the hot water used for air conditioning.

[0016] In the waste heat recovery system of the present invention, the chiller cooling water system comprises a cooling tower located on the supply side of the chiller circulation line, a cooling tower bypass line arranged in the chiller circulation line so as not to pass through the cooling tower, and a chiller inlet side temperature sensor arranged in the chiller circulation line so as to be located between the chiller and the cooling tower. The temperature setting unit of the hot water supply side temperature sensor sets the chiller inlet temperature of the chiller inlet side temperature sensor in conjunction with the hot water temperature setting of the air conditioning hot water system. The chiller cooling water system may be configured to control the cooling tower bypass line according to the temperature detected by the chiller inlet temperature sensor.

[0017] In the waste heat recovery system of the present invention, the chiller cooling water system comprises a cooling tower located on the supply side of the chiller circulation line and equipped with a cooling fan, and a cooling tower outlet side temperature sensor positioned in the chiller circulation line between the chiller and the cooling tower. The temperature setting unit of the hot water supply side temperature sensor sets the temperature of the cooling tower outlet side temperature sensor in conjunction with the temperature setting of the hot water in the air conditioning hot water system. The refrigeration machine cooling water system may be configured to control the cooling fan of the cooling tower according to the detected temperature of the temperature sensor on the outlet side of the cooling tower.

[0018] The waste heat recovery system of the present invention includes a steam supply system arranged via a third heat exchanger on the supply side of the hot water of the air-conditioning hot water system so as to be located between the second heat exchanger and the hot water supply side temperature sensor. The steam supply system is preferably operated in at least one of the following periods: during the period from the completion to the operation of the equipment cooling water system, during the period from the completion to the operation of the refrigeration machine cooling water system, during the failure of the production equipment or the equipment cooling water system, and during the failure of the refrigeration machine cooling water system.

[0019] In the waste heat recovery system of the present invention, the air conditioner is configured to heat and humidify the outside air, and the supply destination of the heated and humidified outside air is a clean room. The production equipment of the equipment cooling water system is preferably installed in the clean room.

Advantages of the Invention

[0020] According to the waste heat recovery system of the present invention, it is possible to enhance the energy-saving effect by recovering waste heat from the refrigeration machine cooling water, and at the same time, it can achieve an excellent effect of interlocking and coordinating the air-conditioning hot water system and the refrigeration machine cooling water system. Also, the waste heat recovery system of the present invention can be applied even during the period until the full-scale operation of the equipment cooling water system and the refrigeration machine cooling water system becomes possible.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic diagram showing an example of the form of the waste heat recovery system according to an embodiment of the present invention. [Figure 2] In the example of the form of the waste heat recovery system according to an embodiment of the present invention, it is a conceptual diagram for controlling the first main pipe two-way valve and the first bypass two-way valve according to the temperature of the equipment cooling water of the cooling water supply side temperature sensor. [Figure 3]This is a conceptual diagram illustrating an example of a waste heat recovery system according to an embodiment of the present invention, in which the first main two-way valve and the first bypass two-way valve are controlled by the temperature of the hot water from the hot water return side temperature sensor. [Figure 4] This is a conceptual diagram illustrating an example of a waste heat recovery system according to an embodiment of the present invention, in which the second main two-way valve and the second bypass two-way valve are controlled by the set temperature of the hot water supply side temperature sensor. [Figure 5] This is a conceptual diagram illustrating an example of a waste heat recovery system according to an embodiment of the present invention, in which the second main two-way valve and the second bypass two-way valve are controlled by the temperature of the chiller cooling water measured by the chiller outlet side temperature sensor. [Figure 6] This is a conceptual diagram illustrating an example of a waste heat recovery system according to an embodiment of the present invention, in which a two-way bypass valve of the cooling tower is controlled by the set temperature of a temperature sensor on the refrigerator inlet side. [Figure 7] This is a conceptual diagram illustrating an example of a waste heat recovery system according to an embodiment of the present invention, in which a cooling fan is controlled by the temperature of the cooling water at the outlet side temperature sensor of the cooling tower. [Figure 8] This graph shows an example of a waste heat recovery system according to an embodiment of the present invention, in which the opening degree of the first main two-way valve and the opening degree of the first bypass two-way valve are proportionally controlled by the temperature of the cooling water of the device. [Figure 9] This graph shows an example of a waste heat recovery system according to an embodiment of the present invention, in which the first main two-way valve and the first bypass two-way valve are controlled ON-OFF based on the temperature of the hot water. [Figure 10] This graph shows an example of a waste heat recovery system according to an embodiment of the present invention, in which the opening degree of the second main two-way valve and the opening degree of the second bypass two-way valve are proportionally controlled by the set temperature (control output) of the hot water. [Figure 11] This graph shows an example of a waste heat recovery system according to an embodiment of the present invention, in which the second main two-way valve and the second bypass two-way valve are controlled ON-OFF based on the temperature of the chiller cooling water. [Figure 12] This graph shows an example of a waste heat recovery system according to an embodiment of the present invention, in which the opening degree of the cooling tower bypass two-way valve is proportionally controlled by the temperature of the cooling water. [Figure 13] This graph shows an example of a waste heat recovery system according to an embodiment of the present invention, in which the cooling fan is controlled ON / OFF based on the temperature of the cooling water. [Figure 14] This is a schematic diagram showing an example of a conventional waste heat recovery system. [Modes for carrying out the invention]

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] Figure 1 shows an example of a waste heat recovery system according to the present invention, and the same reference numerals are used in the figure as in Figure 14.

[0024] In this embodiment, the system includes an air conditioning hot water system 20 that supplies hot water to an air handling unit 1 (an air conditioner that heats outside air) in a clean room C, an equipment cooling water system 23 for a production device 22 located on the return side of the hot water from the air conditioning hot water system 20 via a first heat exchanger 21, a chiller cooling water system 25 located on the hot water supply side of the air conditioning hot water system 20 via a second heat exchanger 24, and a steam supply system 27 located on the hot water supply side of the air conditioning hot water system 20 via a third heat exchanger 26 so as to be positioned between the second heat exchanger 24 and the air handling unit 1.

[0025] In this cleanroom C, which is supplied with air by the air handling unit 1, a spatial passage is located above the target space, and a fan filter unit 28 is provided on the underside of the passage to discharge clean air downwards. A humidifier 29 with a motor damper is also provided on the side of the spatial passage.

[0026] (1) Configuration of the hot water system 20 for air conditioning The air conditioning hot water system 20 includes a hot water circulation line 30 that circulates hot water, connected to the preheating coil 2 and reheating coil 4 of the outdoor air handling unit 1 (air conditioner). The hot water circulation line 30 includes a hot water pump 6 between the third heat exchanger 26 and the outdoor air handling unit 1. The hot water circulation line 30 also includes a hot water supply side temperature sensor 31 between the third heat exchanger 26 and the outdoor air handling unit 1, and a hot water return side temperature sensor 32 between the outdoor air handling unit 1 and the first heat exchanger 21. The hot water supply side temperature sensor 31 also functions as a temperature setting unit for setting the temperature of the hot water. The temperature setting unit of the hot water supply side temperature sensor 31 allows the temperature of the hot water to be arbitrarily set between 19.5°C and 37°C, enabling temperature and humidity control of the outside air supplied from the outdoor air handling unit 1 to the clean room C.

[0027] (2) Configuration of the device cooling water system 23 The device cooling water system 23 includes a device circulation line 33 that circulates device cooling water to the production device 22 via the first heat exchanger 21, and a first bypass line 34 that is connected to the device circulation line 33 so as not to pass through the first heat exchanger 21.

[0028] The production equipment 22 is installed inside the cleanroom C, which is supplied with air by the air handling unit 1, and manufactures semiconductor memory and the like. The production equipment 22 discharges the equipment cooling water into the equipment circulation line 33, and then supplies the equipment cooling water back to the production equipment 22 via the equipment circulation line 33 through the first heat exchanger 21. The equipment cooling water has a high flow rate, but the temperature field that can be recovered by the first heat exchanger 21 is low (the return water temperature of the equipment cooling water is 22.5°C, and the supply water temperature is 20.0°C), eliminating the need for a cooling tower or other configuration that dissipates heat outdoors. The values ​​for the temperature field that can be recovered by the first heat exchanger 21 are just examples and are not limited to specific values. Furthermore, the configuration of the first heat exchanger 21 is not particularly limited as long as it can recover waste heat between the equipment cooling water system 23 and the air conditioning hot water system 20.

[0029] In the device circulation line 33, a first main two-way valve 35 is positioned between the outlet side of the first heat exchanger 21 and the branching point of the first bypass line 34, and a cooling water supply side temperature sensor 36 is positioned between the branching point of the first bypass line 34 and the production device 22. A first bypass two-way valve 37 is also positioned in the first bypass line 34. As shown in Figure 2, the first main two-way valve 35 and the first bypass two-way valve 37 are connected to the device cooling water first control unit 38, and their respective opening degrees are controlled by the temperature of the cooling water supply side temperature sensor 36. Furthermore, as shown in Figure 3, the first main two-way valve 35 and the first bypass two-way valve 37 are connected to the device cooling water second control unit 39, and the flow paths of the device circulation line 33 and the first bypass line 34 are switched according to the set temperature of the hot water return side temperature sensor 32.

[0030] Furthermore, the device circulation line 33 includes a regulating heat exchanger 40 located between the cooling water supply side temperature sensor 36 and the production device 22, and a regulating temperature sensor 41 for the device cooling water located between the regulating heat exchanger 40 and the production device 22. The regulating heat exchanger 40 and the regulating temperature sensor 41 are capable of regulating the temperature of the device cooling water for the production device 22. The regulating heat exchanger 40 is also capable of exchanging heat with the cooling water from the chiller 10. In addition, the device circulation line 33 includes a tank 42 and a water supply pump 43 located on the discharge side of the production device 22, and is configured to circulate the device cooling water from the production device 22.

[0031] (3) Configuration of the chiller cooling water system 25 The chiller cooling water system 25 includes a chiller circulation line 44 that circulates chiller cooling water to the chiller 10 via a second heat exchanger 24, and a second bypass line 45 that is connected to the chiller circulation line 44 so as not to pass through the second heat exchanger 24.

[0032] The chiller 10 is a medium-temperature turbo chiller. The chiller 10 discharges chiller cooling water into the chiller circulation line 44, and then supplies chiller cooling water back to the chiller 10 via the chiller circulation line 44 through the second heat exchanger 24. The chiller cooling water has a high temperature field that can be recovered by the second heat exchanger 24 (the supply water temperature is 37.0°C and the return water temperature is 32.0°C). Here, the values ​​for the temperature field that can be recovered by the second heat exchanger 24 are just examples and are not limited to specific values. Furthermore, the configuration of the second heat exchanger 24 is not particularly limited as long as it can recover waste heat between the chiller cooling water system 25 and the air conditioning hot water system 20. Also, the chiller 10 is not necessarily related to cleanroom C and can be applied to various applications.

[0033] The chiller circulation line 44 has a second main two-way valve 46 positioned between the outlet side of the second heat exchanger 24 and the branching point of the second bypass line 45, and a chiller outlet side temperature sensor 47 is provided between the outlet side of the chiller 10 and the second heat exchanger 24. The second bypass line 45 also has a second bypass two-way valve 48. As shown in Figure 4, the second main two-way valve 46 and the second bypass two-way valve 48 are connected to the chiller side first control unit 49, and their respective opening degrees are controlled by the set temperature of the hot water supply side temperature sensor 31. Furthermore, as shown in Figure 5, the second main two-way valve 46 and the second bypass two-way valve 48 are connected to the chiller side second control unit 50, which switches the flow paths of the chiller circulation line 44 and the second bypass line 45 based on the temperature of the chiller outlet side temperature sensor 47. In addition, the chiller outlet side temperature sensor 47 is linked to the temperature setting of the temperature setting unit of the hot water supply side temperature sensor 31.

[0034] Furthermore, the chiller circulation line 44 has a cooling tower 13 and a pump 14 positioned between the outlet side of the second heat exchanger 24 and the inlet side of the chiller 10, and also includes a cooling tower bypass line 51 that is positioned to avoid passing through the cooling tower 13. The chiller circulation line 44 is equipped with a chiller inlet side temperature sensor 52 between the outlet side of the cooling tower 13 and the inlet side of the chiller 10, and the cooling tower bypass line 51 is equipped with a cooling tower bypass two-way valve 53. Here, as shown in Figure 6, the cooling tower bypass two-way valve 53 is connected to the chiller side third control unit 54, and switches the flow path between the chiller circulation line 44 and the cooling tower bypass line 51 according to the set temperature of the chiller inlet side temperature sensor 52. The chiller inlet side temperature sensor 52 is also linked to the temperature setting of the temperature setting unit of the hot water supply side temperature sensor 31 via the set temperature of the chiller outlet side temperature sensor 47.

[0035] Furthermore, the chiller circulation line 44 is equipped with a cooling tower outlet side temperature sensor 55 located near the outlet of the cooling tower 13, between the outlet side of the cooling tower 13 and the inlet side of the chiller 10. As shown in Figure 7, the cooling tower 13 is equipped with a cooling fan 13a, which is connected to the chiller side fourth control unit 56, and its rotation speed is controlled by the temperature detected by the cooling tower outlet side temperature sensor 55. The cooling tower outlet side temperature sensor 55 is also linked to the temperature setting of the hot water supply side temperature sensor 31 via the set temperature of the chiller outlet side temperature sensor 47.

[0036] Furthermore, the chiller circulation line 44 is equipped with a return line 57 that returns chiller cooling water from the chiller 10 to the cooling tower 13 instead of the second heat exchanger 24, and a return two-way valve (flow control valve) 58 that opens and closes the return line 57, so that the required flow rate of chiller cooling water to the second heat exchanger 24 can be secured by adjusting the return two-way valve 58.

[0037] (4) Configuration of the steam supply system 27 The steam supply system 27 supplies steam to the third heat exchanger 26 and includes a steam drain discharge line 59 that discharges the condensed steam outside the heat exchanger after heat exchange. The steam drain discharge line 59 is equipped with a steam generator (not shown), a two-way steam valve 60 on the inlet side of the third heat exchanger 26, and a steam temperature sensor 61 on the outlet side of the third heat exchanger 26. The two-way steam valve 60 controls the flow rate based on the temperature detected by the steam temperature sensor 61. The steam supply system 27 is configured to operate during the period from the completion of the equipment cooling water system 23 until it becomes operational, during the period from the completion of the chiller cooling water system 25 until it becomes operational, in the event of a failure of the production equipment 22 or the equipment cooling water system 23, or in the event of a failure of the chiller cooling water system 25.

[0038] The operation of an embodiment of the present invention will be explained.

[0039] The outdoor air handling unit 1 (an air conditioner that heats outside air) heats the outside air with a preheating coil 2 and a reheating coil 4, and humidifies it with a humidifier 3. At this time, the outdoor air handling unit 1 lowers the temperature of the hot water to a temperature that can maintain the room temperature due to the heat generated inside cleanroom C. Also, as the humidification of the outside air decreases due to the lowering of the temperature of the outdoor air handling unit 1, the insufficient humidification is compensated for by a humidifier 29 with a motor damper inside cleanroom C.

[0040] (1) In the air conditioning hot water system 20, the hot water returned from the outdoor air handling unit 1 to the hot water circulation line 30 is heated in the first heat exchanger 21, and then heated again in the second heat exchanger 24 before being supplied to the outdoor air handling unit 1. To give a specific example, the hot water returned from the outdoor air handling unit 1 to the hot water circulation line 30 is heated from 14.5°C to 16.8°C in the first heat exchanger 21, and then heated again from 28.0°C to 35.0°C in the second heat exchanger 24.

[0041] Furthermore, the hot water returned from the preheating coil 2 and reheating coil 4 of the air handling unit 1 to the hot water circulation line 30 is heated in the third heat exchanger 26 to replenish any insufficient waste heat during the period from when the equipment cooling water system 23 is completed and operational, during the period from when the chiller cooling water system 25 is completed and operational, in the event of a failure of the production equipment 22 or the equipment cooling water system 23, or in the event of a failure of the chiller cooling water system 25. After the production equipment 22 has been fully implemented as planned in the factory's design, fluctuations in the air conditioning load within the cleanroom C become smaller, and setting changes are not frequent. Therefore, it becomes easy to manually set the temperature of the hot water using the temperature setting unit of the hot water supply side temperature sensor 31 while monitoring the indoor load.

[0042] (2) In the equipment cooling water system 23, the equipment cooling water discharged from the production equipment 22 to the equipment circulation line 33 has waste heat recovered via the first heat exchanger 21. To give a specific example, the equipment cooling water discharged from the production equipment 22 is cooled from 22.5°C to 20.0°C by the first heat exchanger 21.

[0043] The first cooling water control unit 38 (see Figure 2) proportionally controls the opening of the first main two-way valve 35 and the first bypass two-way valve 37 based on the temperature of the cooling water detected by the cooling water supply side temperature sensor 36 (see Figure 8), and adjusts the flow rate of the cooling water in the device circulation line 33 and the first bypass line 34. More specifically, when the temperature of the cooling water is high, the opening of the first main two-way valve 35 is controlled to open and the opening of the first bypass two-way valve 37 is controlled to close, and when the temperature of the cooling water is low, the opening of the first main two-way valve 35 is controlled to close and the opening of the first bypass two-way valve 37 is controlled to open. Here, Figure 8 shows an example where the temperature of the cooling water is 20°C. Furthermore, when the temperature of the device cooling water reaches 20°C, cooling of the device cooling water using the adjustment heat exchanger 40 and adjustment temperature sensor 41 in the device circulation line 33 becomes unnecessary, eliminating heat exchange of the chiller cooling water by the adjustment heat exchanger 40 and reducing the load on the chiller 10.

[0044] The second control unit for the cooling water of the device (see Figure 3) performs ON-OFF control (see Figure 9) such as closing the first main two-way valve 35 and opening the first bypass two-way valve 37 when the temperature of the hot water detected by the hot water return side temperature sensor 32 of the air conditioning hot water system 20 exceeds the set temperature, thereby switching the flow of the cooling water of the device from the device circulation line 33 to the first bypass line 34. More specifically, the hot water return side temperature sensor 32 is set to a temperature of 21.5°C, and when the temperature of the hot water in the hot water circulation line 30 exceeds 21.5°C, the cooling water of the device will rise in temperature via the first heat exchanger 21, resulting in increased energy. Therefore, the entire amount of cooling water of the device is diverted to the first bypass line 34 to prevent the cooling water from rising in temperature. On the other hand, when the temperature of the hot water detected by the hot water return side temperature sensor 32 of the air conditioning hot water system 20 falls below a certain temperature below the set temperature, ON-OFF control is performed to open the first main two-way valve 35 and close the first bypass two-way valve 37 (see Figure 9), switching the flow of the device cooling water from the first bypass line 34 to the device circulation line 33.

[0045] (3) In the chiller cooling water system 25, the chiller cooling water discharged from the chiller 10 to the chiller circulation line 44 has its waste heat recovered via the second heat exchanger 24. To give a specific example, the chiller cooling water supplied from the chiller 10 is reduced in temperature from 37.0°C to 32.0°C by the second heat exchanger 24.

[0046] The first control unit 49 on the chiller side (see Figure 4) proportionally controls the opening of the second main two-way valve 46 and the second bypass two-way valve 48 based on the set temperature of the hot water supply side temperature sensor 31 of the air conditioning hot water system 20 (see Figure 10), and adjusts the flow rate of chiller cooling water in the chiller circulation line 44 and the second bypass line 45. More specifically, when the set temperature (control output) is high, the opening of the second main two-way valve 46 is controlled to open and the opening of the second bypass two-way valve 48 is controlled to close, and when the set temperature (control output) is low, the opening of the second main two-way valve 46 is controlled to close and the opening of the second bypass two-way valve 48 is controlled to open.

[0047] The second control unit 50 on the chiller side (see Figure 5) determines the set temperature of the chiller outlet side temperature sensor 47 in conjunction with the set temperature of the hot water supply side temperature sensor 31 of the air conditioning hot water system 20. To give a specific example, the set temperature of the chiller outlet side temperature sensor 47 is set to a temperature that is 2°C higher than the set temperature of the hot water supply side temperature sensor 31, with a lower limit of 25°C. Furthermore, when the temperature of the chiller cooling water detected by the chiller outlet side temperature sensor 47 falls below the set temperature by a certain amount (for example, the set temperature minus 2°C), the second control unit 50 on the chiller side (see Figure 5) performs ON-OFF control to close the second main pipe two-way valve 46 and open the second bypass two-way valve 48 (see Figure 11), switching the flow of chiller cooling water from the chiller circulation line 44 to the second bypass line 45. This is because if the temperature of the chiller cooling water in the chiller circulation line 44 falls below the set temperature of the chiller outlet side temperature sensor 47 by a certain amount, waste heat cannot be recovered by the second heat exchanger 24. On the other hand, when the temperature of the chiller cooling water detected by the chiller outlet temperature sensor 47 exceeds a certain temperature above the set temperature, ON-OFF control is performed to open the second main two-way valve 46 and close the second bypass two-way valve 48 (see Figure 11), switching the flow of chiller cooling water from the second bypass line 45 to the chiller circulation line 44.

[0048] The third control unit 54 on the chiller side (see Figure 6) determines the set temperature of the chiller inlet temperature sensor 52 in accordance with the set temperature of the chiller outlet temperature sensor 47, in conjunction with the set temperature of the hot water supply side temperature sensor 31 of the air conditioning hot water system 20. To give a specific example, the set temperature of the chiller inlet temperature sensor 52 is set to a temperature that is 5°C lower than the set temperature of the chiller outlet temperature sensor 47, with a lower limit of 20°C. The third control unit 54 on the chiller side also uses the set temperature of the chiller inlet temperature of the cooling water in the cooling tower 13 as a reference and proportionally controls the cooling tower bypass two-way valve 53 to close if the temperature detected by the chiller inlet temperature sensor 52 is high, and to open the cooling tower bypass two-way valve 53 if the temperature is low (see Figure 12).

[0049] The chiller-side fourth control unit 56 (see Figure 7) determines the set temperature of the cooling tower outlet side temperature sensor 55 in accordance with the set temperature of the chiller outlet side temperature sensor 47, in conjunction with the set temperature of the hot water supply side temperature sensor 31 of the air conditioning hot water system 20. To give a specific example, the set temperature of the cooling tower outlet side temperature sensor 55 is set to a temperature that is 5°C lower than the set temperature of the chiller outlet side temperature sensor 47, with a lower limit of 20°C. Furthermore, the chiller-side fourth control unit 56 uses the set temperature of the cooling tower outlet side temperature of the cooling water in the cooling tower 13 as a reference and performs ON-OFF control, turning on the cooling fan 13a of the cooling tower 13 if the temperature detected by the cooling tower outlet side temperature sensor 55 is high, and turning off the cooling fan 13a if the temperature is low (see Figure 13).

[0050] (4) In the steam supply system 27, the steam circulating through the steam drain discharge line 59 is used during the period from the completion of the equipment cooling water system 23 until it is operational, during the period from the completion of the chiller cooling water system 25 until it is operational, in the event of a failure of the production equipment 22 or the equipment cooling water system 23, or in the event of a failure of the chiller cooling water system 25. When the production equipment 22, the equipment cooling water system 23, and the chiller cooling water system 25 are operating properly, the steam in the steam drain discharge line 59 will not circulate through the third heat exchanger 26.

[0051] As described above, an example of a waste heat recovery system comprises an air conditioning hot water system 20 that supplies hot water to an air handling unit 1 (air conditioner) that heats the outside air, an equipment cooling water system 23 for a production device 22 located on the return side of the hot water from the air conditioning hot water system 20 via a first heat exchanger 21, and a chiller cooling water system 25 located on the hot water supply side of the air conditioning hot water system 20 via a second heat exchanger 24. The air conditioning hot water system 20 includes a hot water circulation line 30 that circulates hot water to the air conditioner, and a second heat exchanger 24. The device cooling water system 23 includes a device circulation line 33 that circulates device cooling water to the production equipment 22 via the first heat exchanger 21, a first bypass line 34 that is connected to the device circulation line 33 so as not to pass through the first heat exchanger 21, and a cooling water supply side temperature sensor 36 located on the supply side of the device circulation line 33, and the detection of the cooling water supply side temperature sensor 36 The flow rate of the cooling water in the equipment circulation line 33 and the first bypass line 34 is controlled according to the temperature to adjust the temperature of the cooling water that is returned to the production equipment 22. The waste heat of the cooling water in the equipment cooling water system 23 is used to raise the temperature of the hot water in the air conditioning hot water system 20 via the first heat exchanger 21. The chiller cooling water system 25 includes a chiller circulation line 44 that circulates chiller cooling water to the chiller via the second heat exchanger 24, and a second bypass line 45 that is connected to the chiller circulation line 44 without passing through the second heat exchanger 24. The flow rate of the chiller cooling water in the chiller circulation line 44 and the second bypass line 45 is controlled according to the temperature detected by the hot water supply side temperature sensor 31, and the hot water in the air conditioning hot water system 20 is reheated via the second heat exchanger 24. The temperature setting unit of the hot water supply side temperature sensor 31 is configured to set the temperature of the hot water in the air conditioning hot water system 20 via the first heat exchanger 21 and the second heat exchanger 24, as well as the temperature of the chiller cooling water in the chiller cooling water system 25. In this way, the waste heat from the cooling water of the device cooling water system 23 is used to raise the temperature of the hot water in the air conditioning hot water system 20, and then the waste heat from the cooling water of the chiller in the chiller cooling water system 25 is used to further raise the temperature of the hot water in the air conditioning hot water system 20 to adjust it. As a result, the hot water in the air conditioning hot water system 20 can be easily and appropriately heated, and at the same time, the energy saving effect from recovering waste heat from the chiller cooling water can be enhanced.Furthermore, conventionally, the method used was to operate the system with a fixed chiller cooling water temperature to obtain the hot water temperature for the hot water system 20 required for air conditioning of the air handling unit 1. However, if the chiller cooling water temperature can be lowered in the chiller cooling water system 25, that is, when the heat load from production equipment in cleanroom C, where there is no need to heat the air handling unit 1, becomes large, or when the outside air temperature is higher than planned, it is possible to operate the chiller 10 in a high-efficiency range, further enhancing the energy-saving effect. In addition, when the temperature of the hot water is set using the temperature setting unit of the hot water supply side temperature sensor 31, the temperature of the cooling water in the chiller cooling water system 25 is set in conjunction, so the hot water system 20 for air conditioning and the chiller cooling water system 25 can be linked and synchronized. Furthermore, the air conditioning hot water system 20 is connected in series with the equipment cooling water system 23 and the chiller cooling water system 25, and the waste heat is recovered by the first heat exchanger 21 and the second heat exchanger 24, so that the air conditioning hot water system 20, the equipment cooling water system 23 and the chiller cooling water system 25 can be linked and synchronized.

[0052] Furthermore, in an example of the waste heat recovery system configuration, the air conditioning hot water system 20 is equipped with a hot water return side temperature sensor 32 positioned in the hot water circulation line 30 between the outdoor air handling unit 1 (air conditioner) and the first heat exchanger 21. The device cooling water system 23 is configured to flow the entire amount of device cooling water into the first bypass line 34 according to the temperature detected by the hot water return side temperature sensor 32, thereby preventing the device cooling water from rising in temperature due to heat exchange with the hot water of the air conditioning hot water system 20. In this way, the device cooling water system 23 is prevented from becoming an energy-intensive system, waste heat is suitably recovered in the first heat exchanger 21, and the air conditioning hot water system 20 and the device cooling water system 23 can be appropriately linked and synchronized.

[0053] Furthermore, in an example of the waste heat recovery system configuration, the chiller cooling water system 25 is equipped with a chiller outlet side temperature sensor 47 positioned in the chiller circulation line 44 between the chiller 10 and the second heat exchanger 24. The temperature setting unit of the hot water supply side temperature sensor 31 sets the chiller outlet temperature of the chiller outlet side temperature sensor 47 in conjunction with the temperature setting of the hot water in the air conditioning hot water system 20. The chiller cooling water system 25 flows the entire amount of chiller cooling water to the second bypass line 45 according to the temperature detected by the chiller outlet side temperature sensor 47, and is configured to handle cases where the chiller cooling water cannot exchange heat with the air conditioning hot water. In this way, the chiller cooling water system 25 is prevented from becoming an energy source, waste heat is suitably recovered in the second heat exchanger 24, and the air conditioning hot water system 20 and the chiller cooling water system 25 can be appropriately linked and synchronized. Furthermore, when the temperature of the hot water is set using the temperature setting unit of the hot water supply side temperature sensor 31, the chiller outlet temperature of the chiller outlet side temperature sensor 47 is set in conjunction, thus further linking and integrating the air conditioning hot water system 20 and the chiller cooling water system 25.

[0054] Furthermore, in an example of the waste heat recovery system configuration, the chiller cooling water system 25 includes a cooling tower 13 located on the supply side of the chiller circulation line 44, a cooling tower bypass line 51 arranged in the chiller circulation line 44 so as not to pass through the cooling tower 13, and a chiller inlet side temperature sensor 52 arranged in the chiller circulation line 44 so as to be located between the chiller 10 and the cooling tower 13. The temperature setting unit of the hot water supply side temperature sensor 31 sets the chiller inlet temperature of the chiller inlet side temperature sensor 52 in conjunction with the temperature setting of the hot water in the air conditioning hot water system 20, and the chiller cooling water system 25 is configured to control the cooling tower bypass line 51 according to the temperature detected by the chiller inlet side temperature sensor 52. In this way, the chiller cooling water in the chiller circulation line 44 is brought to an appropriate temperature, and the hot water in the air conditioning hot water system 20 is reheated via the second heat exchanger 24, so that the hot water in the air conditioning hot water system 20 can be easily and appropriately heated, and at the same time the energy saving effect from waste heat recovery from the chiller cooling water can be enhanced. Furthermore, when the temperature of the hot water is set using the temperature setting unit of the hot water supply side temperature sensor 31, the temperature of the chiller inlet side temperature sensor 52 is set in conjunction with the temperature setting of the chiller outlet side temperature sensor 47, thereby further linking and coordinating the air conditioning hot water system 20 and the chiller cooling water system 25.

[0055] Furthermore, in an example of the waste heat recovery system configuration, the chiller cooling water system 25 includes a cooling tower 13 located on the supply side of the chiller circulation line 44 and equipped with a cooling fan 13a, and a cooling tower outlet side temperature sensor 55 positioned in the chiller circulation line 44 between the chiller 10 and the cooling tower 13. The temperature setting unit of the hot water supply side temperature sensor 31 sets the temperature of the cooling tower outlet side temperature sensor 55 in conjunction with the temperature setting of the hot water in the air conditioning hot water system 20, and the chiller cooling water system 25 is configured to control the cooling fan 13a of the cooling tower 13 according to the temperature detected by the cooling tower outlet side temperature sensor 55. In this way, the chiller cooling water in the chiller circulation line 44 is brought to an appropriate temperature, and the hot water in the air conditioning hot water system 20 is reheated via the second heat exchanger 24, thereby easily and appropriately heating the hot water in the air conditioning hot water system 20 and simultaneously enhancing the energy-saving effect of recovering waste heat from the chiller cooling water. Furthermore, when the temperature of the hot water is set using the temperature setting unit of the hot water supply side temperature sensor 31, the temperature of the cooling tower outlet side temperature sensor 55 is set in conjunction with the temperature setting of the chiller outlet side temperature sensor 47, thereby further linking and connecting the air conditioning hot water system 20 and the chiller cooling water system 25.

[0056] Furthermore, in an example of the waste heat recovery system configuration, a steam supply system 27 is provided, positioned between the second heat exchanger 24 and the hot water supply side temperature sensor 31, on the hot water supply side of the air conditioning hot water system 20 via a third heat exchanger 26. The steam supply system 27 is operated during at least one of the following periods: the period from the completion of the equipment cooling water system 23 until it is operational, the period from the completion of the chiller cooling water system 25 until it is operational, in the event of a failure of the production equipment 22 or the equipment cooling water system 23, or in the event of a failure of the chiller cooling water system 25. In this way, the hot water in the air conditioning hot water system 20 can be easily and appropriately heated according to various situations, and the degree of freedom in the interlocking and coordination of the air conditioning hot water system 20, the equipment cooling water system 23, and the chiller cooling water system 25 can be improved.

[0057] Furthermore, in an example of a waste heat recovery system configuration, the air handling unit 1 (air conditioner) is configured to heat and humidify outside air, and the heated and humidified outside air is supplied to the cleanroom C. The production equipment 22 of the equipment cooling water system 23 may also be installed inside the cleanroom C. In this way, the hot water system 20 for air conditioning and the equipment cooling water system 23 can be easily linked and connected. Here, the waste heat source is not limited to the production equipment 22 inside the cleanroom, but may also be equipment outside the cleanroom.

[0058] It should be noted that the waste heat recovery system of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0059] 1 Outdoor conditioner (air conditioner) 10 Refrigeration unit 13 Cooling Tower 13a cooling fan 20 Air conditioning hot water system 21 First heat exchanger 22 Production equipment 23 Equipment cooling water system 24 Second heat exchanger 25 Refrigerator cooling water system 26 Third heat exchanger 27 Steam supply system 30 Hot water circulation line 31. Hot water supply side temperature sensor 32 Hot water return side temperature sensor 33. Equipment circulation line 34 First Bypass Line 35. First main two-way valve 36. Cooling water supply side temperature sensor 37 First Bypass Two-Way Valve 44 Refrigeration unit circulation line 45 Second Bypass Line 46 Second Main Two-Way Valve 47. Refrigeration unit outlet temperature sensor 48 Second Bypass Two-Way Valve 51 Cooling tower bypass line 52 Refrigeration unit inlet temperature sensor 53 Cooling tower bypass two-way valve 55 Cooling tower outlet side temperature sensor C Cleanroom

Claims

1. The system comprises an air conditioning hot water system that supplies hot water to an air conditioner that heats the outside air, a production equipment cooling water system that is arranged on the return side of the hot water of the air conditioning hot water system via a first heat exchanger, and a chiller cooling water system that is arranged on the supply side of the hot water of the air conditioning hot water system via a second heat exchanger. The aforementioned hot water system for air conditioning includes a hot water circulation line that circulates hot water to the air conditioner, and a hot water supply side temperature sensor that is positioned in the hot water circulation line between the second heat exchanger and the air conditioner and also serves as a temperature setting unit. The aforementioned device cooling water system comprises a device circulation line that circulates device cooling water to the production equipment via a first heat exchanger, a first bypass line connected to the device circulation line so as not to pass through the first heat exchanger, and a cooling water supply side temperature sensor located on the supply side of the device circulation line. The system controls the flow rate of device cooling water in the device circulation line and the first bypass line according to the temperature detected by the cooling water supply side temperature sensor, thereby adjusting the temperature of the device cooling water returned to the production equipment. Furthermore, the waste heat from the device cooling water in the device cooling water system is used to raise the temperature of the hot water in the air conditioning hot water system via the first heat exchanger. The aforementioned chiller cooling water system includes a chiller circulation line that circulates chiller cooling water to the chiller via a second heat exchanger, and a second bypass line that is connected to the chiller circulation line without passing through the second heat exchanger. The flow rate of chiller cooling water in the chiller circulation line and the second bypass line is controlled according to the temperature detected by the hot water supply side temperature sensor, and the hot water in the air conditioning hot water system is reheated via the second heat exchanger. The temperature setting unit of the hot water supply side temperature sensor is configured to set the temperature of the hot water in the air conditioning hot water system via the first heat exchanger and the second heat exchanger, as well as to set the temperature of the chiller cooling water in the chiller cooling water system. A waste heat recovery system characterized by the following features.

2. The aforementioned hot water system for air conditioning includes a hot water return side temperature sensor positioned in the hot water circulation line between the air conditioner and the first heat exchanger. The waste heat recovery system according to claim 1, characterized in that the device cooling water system is configured to flow the entire amount of device cooling water to the first bypass line according to the temperature detected by the hot water return side temperature sensor, thereby preventing the device cooling water from rising in temperature due to heat exchange with the hot water of the air conditioning hot water system.

3. The aforementioned chiller cooling water system includes a chiller outlet side temperature sensor positioned in the chiller circulation line between the chiller and the second heat exchanger. The temperature setting unit of the hot water supply side temperature sensor sets the chiller outlet temperature of the chiller outlet side temperature sensor in conjunction with the hot water temperature setting of the air conditioning hot water system. The waste heat recovery system according to claim 1, characterized in that the chiller cooling water system is configured to flow the entire amount of chiller cooling water to a second bypass line according to the temperature detected by the chiller outlet side temperature sensor, in order to address cases where the chiller cooling water cannot exchange heat with the hot water for air conditioning.

4. The aforementioned chiller cooling water system comprises a cooling tower located on the supply side of the chiller circulation line, a cooling tower bypass line arranged in the chiller circulation line so as not to pass through the cooling tower, and a chiller inlet side temperature sensor arranged in the chiller circulation line so as to be located between the chiller and the cooling tower. The temperature setting unit of the hot water supply side temperature sensor sets the chiller inlet temperature of the chiller inlet side temperature sensor in conjunction with the hot water temperature setting of the air conditioning hot water system. The waste heat recovery system according to claim 1, characterized in that the chiller cooling water system is configured to control the cooling tower bypass line according to the temperature detected by the chiller inlet side temperature sensor.

5. The chiller cooling water system comprises a cooling tower located on the supply side of the chiller circulation line and equipped with a cooling fan, and a cooling tower outlet side temperature sensor positioned in the chiller circulation line between the chiller and the cooling tower. The temperature setting unit of the hot water supply side temperature sensor sets the temperature of the cooling tower outlet side temperature sensor in conjunction with the temperature setting of the hot water in the air conditioning hot water system. The waste heat recovery system according to claim 1, characterized in that the chiller cooling water system is configured to control the cooling fan of the cooling tower according to the temperature detected by the cooling tower outlet side temperature sensor.

6. The system includes a steam supply system located on the hot water supply side of the air conditioning hot water system via a third heat exchanger, positioned between the second heat exchanger and the hot water supply side temperature sensor. The waste heat recovery system according to claim 1, characterized in that the steam supply system is operated during at least one of the following periods: the period from the completion of the equipment cooling water system until it is operational, the period from the completion of the chiller cooling water system until it is operational, in the event of a failure of the production equipment or the equipment cooling water system, or in the event of a failure of the chiller cooling water system.

7. The aforementioned air conditioner is configured to heat and humidify outside air, and the heated and humidified outside air is supplied to a clean room. The waste heat recovery system according to claim 1, characterized in that the production equipment for the cooling water system of the apparatus is installed in the clean room.

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