JP5503058B2 - Heat source system - Google Patents

Description

  The present invention relates to a heat source system that performs a free cooling operation for cooling cold water flowing out from a heat load device using a heat exchanger while stopping the operation of a refrigerator when the state of outside air is a predetermined condition.

  The feed cooling water from the cooling tower is supplied to either the refrigerator or the heat exchanger via the valve mechanism, and the return cooling water from the refrigerator or the heat exchanger is returned to the cooling tower via the valve mechanism. Supplying cold water from either the cooling water circulation system, the refrigerator or the heat exchanger to the heat load device via the valve mechanism, and returning the cold water from the heat load device via the valve mechanism to the refrigerator or There is a heat source system that includes a chilled water circulation system that returns to a heat exchanger, and in which a refrigerator and a heat exchanger are arranged in parallel with respect to a heat load device (see Patent Document 1).

  In the summer, this heat source system sends the cooling water from the cooling tower to the refrigerator, switches the valve mechanism to return the returning cooling water from the refrigerator to the cooling tower, and uses the cold water from the refrigerator as a heat load device. Normal operation is performed to switch the valve mechanism so that the cold water returned from the heat load device is returned to the refrigerator. In winter, the cooling water from the cooling tower is sent to the heat exchanger, the valve mechanism is switched so that the return cooling water from the heat exchanger is returned to the cooling tower, and the cold water from the heat exchanger is supplied to the heat load device. Free cooling operation is performed to switch the valve mechanism so that the cold water returned from the heat load device is returned to the heat exchanger.

JP-A-5-58034

  The heat source system disclosed in the patent document uses a cooling tower in the winter to cool the cooling water, and sends the cooling water to a heat exchanger to perform free cooling operation to cool the cold water flowing out from the heat load device. The heat load device can be cooled without operating the refrigerator, and the system can save energy. In this heat source system, it is necessary to cool the cold water supplied to the heat load device through the heat exchanger to such an extent that the heat load device can be cooled, and in order to sufficiently cool the cold water in the heat exchanger, The cooling water supplied to the water must be sufficiently cooled through the cooling tower. Therefore, in this system, the free cooling operation is performed only when the temperature of the outside air that can reliably and sufficiently lower the temperature of the cooling water in the cooling tower is low.

  On the other hand, in this heat source system, since the refrigerator and the heat exchanger are arranged in parallel to the heat load device, both the refrigerator and the heat exchanger cannot be used at the same time. A plurality of refrigerators are installed, and the cold water is pre-cooled using a heat exchanger and the load of some of the refrigerators is reduced using the pre-cooled cold water. Precooling operation that can be reduced cannot be performed. Therefore, this heat source system cannot perform pre-cooling operation when the temperature is relatively low as in the intermediate period excluding summer and winter, and cannot save energy in the intermediate period.

  An object of the present invention is to perform a precooling operation that reduces the load of some of the refrigerators using precooled cold water when a plurality of refrigerators are installed. An object of the present invention is to provide a heat source system that can save energy during the period of removal.

  The premise of the present invention for solving the above-mentioned problems is a heat load device that uses cold water, a first to nth refrigerator that individually cools cold water that has flowed out of the heat load device, and a first to nth refrigerator. Supply to at least one of the first to n-th refrigerator and the heat exchanger via a predetermined switching mechanism, and a heat exchanger for cooling the cold water flowing out from the heat load device instead of at least the first refrigerator First to m-th cooling towers for cooling the cooling water to be supplied, and when the outside air is in a predetermined condition, the operation of the first to n-th refrigerators is stopped and supplied to the heat exchanger This is a heat source system that performs a free cooling operation that cools cooling water flowing out from a heat load device using a heat exchanger while cooling the cooling water using a cooling tower.

  The first feature of the heat source system of the present invention based on the above premise is that at least the first refrigerator and the heat exchanger of the first to n-th refrigerators are arranged in series with respect to the heat load device. Compare the outside temperature with the comparison temperature, which is the temperature obtained by subtracting the preset temperature from the chilled water temperature just before flowing into the heat exchanger, and supply it to the refrigerator if the outside temperature exceeds the comparison temperature Normal operation of cooling the cooling water flowing out from the heat load device using at least one of the first to nth refrigerators without using the heat exchanger while cooling the cooling water to be cooled by the cooling tower If the outside air temperature is lower than the comparison temperature and the outside air temperature exceeds the set temperature, the operation of at least the first refrigerator of the first to nth refrigerators is stopped, and the stopped refrigerator is removed. With at least one of the remaining refrigerators The cooling water supplied to the exchanger is cooled by the cooling tower, and the cold water flowing out from the heat load device is pre-cooled using the heat exchanger, and at least of the remaining refrigerators excluding the stopped refrigerator One is to perform a pre-cooling operation for cooling the cold water flowing out from the heat load device. When the outside air temperature is equal to or lower than the comparison temperature and the outside air temperature is equal to or lower than the set temperature, the free cooling operation is performed.

  As an example of the heat source system having the first feature, the heat source system includes a control device that performs any one of a normal operation, a pre-cooling operation, and a free cooling operation, and the control device measures the outside air temperature. Means, a chilled water temperature measuring means for measuring the chilled water temperature immediately before flowing into the heat exchanger, and a temperature comparing means for comparing the measured outside air temperature with a comparative temperature. When the comparison temperature is exceeded, normal operation is performed, and when the outside air temperature is lower than the comparison temperature and the outside air temperature exceeds the set temperature, precooling operation is performed, and the outside air temperature is below the comparison temperature. If the outside air temperature is below the set temperature, perform free cooling operation.

  The second feature of the heat source system of the present invention based on the premise is that at least the first refrigerator and the heat exchanger of the first to n-th refrigerators are arranged in series with respect to the heat load device, Compare the outside temperature with the comparison temperature, which is the temperature obtained by subtracting the preset temperature from the chilled water temperature just before flowing into the heat exchanger, and supply it to the refrigerator if the outside temperature exceeds the comparison temperature Normal operation of cooling the cooling water flowing out from the heat load device using at least one of the first to nth refrigerators without using the heat exchanger while cooling the cooling water to be cooled by the cooling tower When the outside air temperature is equal to or lower than the comparison temperature and is an intermediate period excluding summer and winter, the operation of at least the first refrigerator of the first to nth refrigerators is stopped, and the stopped refrigerator At least of the remaining freezer The cooling water supplied to the heat exchanger and the heat exchanger is cooled by the cooling tower, while using the heat exchanger, the cold water flowing out from the heat load device is precooled, and the remaining refrigerators excluding the stopped refrigerator A pre-cooling operation for cooling the cold water flowing out from the heat load device is performed using at least one of the above, and a free cooling operation is performed when the outside air temperature is equal to or lower than the comparison temperature and in the winter.

  As an example of the heat source system having the second feature, the heat source system includes a control device that performs any of normal operation, precooling operation, and free cooling operation, and the control device measures the outside air temperature. Means, a chilled water temperature measuring means for measuring the chilled water temperature immediately before flowing into the heat exchanger, and a temperature comparing means for comparing the measured outside air temperature with a comparative temperature. When the comparison temperature is exceeded, normal operation is performed, and when the outside air temperature is below the comparison temperature and in the intermediate period excluding summer and winter, precooling operation is performed, and the outside temperature is below the comparison temperature However, if it is winter, free cooling operation will be implemented.

  As another example of the heat source system having the first and second features, in normal operation, the number of operating first to n-th refrigerators and the number of operating first to m-th cooling towers are required by the heat load device. In accordance with the load amount, in the pre-cooling operation, the remaining number of operating refrigerators excluding the stopped refrigerator and the number of operating cooling towers are determined according to the required load amount of the heat load device.

  As another example of the heat source system having the first and second features, the set temperature is 2 to 3 ° C.

  According to the heat source system of the present invention, since at least the first refrigerator and the heat exchanger of the first to nth refrigerators are arranged in series with respect to the heat load device, at least the first refrigerator. For example, when a plurality of refrigerators are installed in the heat source system, precooled chilled water can be used while precooling the chilled water using the heat exchanger. By using it, a pre-cooling operation that reduces the load on some of the refrigerators can be performed. Therefore, this heat source system is used for the period when the outside air temperature is sufficiently lowered (when the outside air temperature is below the comparison temperature and the outside air temperature is below the set temperature, or when the outside air temperature is below the comparison temperature and the winter In the case where the outside air temperature is not sufficiently lowered (for example, when the outside air temperature is lower than the comparison temperature and the outside air temperature exceeds the set temperature, or Precooling operation can be performed in the case where the outside air temperature is equal to or lower than the comparative temperature and in the intermediate period excluding summer and winter), and energy saving of the system can be achieved during the period excluding summer.

  The heat source system is a temperature obtained by subtracting a preset temperature from the chilled water temperature just before the comparative temperature flows into the heat exchanger, and if the outside air temperature exceeds the comparative temperature, the heat source system uses a heat exchanger. Since the chilled water cannot be cooled, a normal operation is performed to cool the chilled water flowing out from the heat load device using at least one of the first to nth refrigerators without using the heat exchanger. On the other hand, when the outside air temperature is below the comparison temperature and the outside air temperature exceeds the set temperature, or when the outside air temperature is below the comparison temperature and in the intermediate period excluding summer and winter, or the outside air temperature is When the temperature is below the comparison temperature and the outside air temperature is below the set temperature, or when the outside air temperature is below the comparison temperature and in the winter, the cold water can be sufficiently cooled using a heat exchanger. Therefore, for example, by performing a pre-cooling operation that uses both at least one refrigerator and a heat exchanger at the same time during a period when the outside air temperature is not sufficiently lowered, energy can be saved during that period. By performing a free cooling operation in which the refrigerator is stopped during a period when the outside air temperature is sufficiently lowered, energy saving can be achieved during that period. By performing pre-cooling operation or free cooling operation, the heat source system can reduce energy consumption (power consumption) by performing normal operation during that period, and by performing pre-cooling operation and free cooling operation for a long period of time. , Energy saving of the system can be achieved throughout the year.

  Including a control device that performs any one of the normal operation, the pre-cooling operation, and the free cooling operation, the control device compares the outside air temperature with the comparison temperature, and performs the normal operation when the outside air temperature exceeds the comparison temperature, Precooling operation is performed when the outside air temperature is below the comparison temperature and the outside air temperature exceeds the set temperature, and free cooling operation is performed when the outside air temperature is below the comparison temperature and the outside air temperature is below the set temperature. When the outside air temperature exceeds the comparison temperature, the heat source system that performs the operation determines that the control device cannot sufficiently cool the chilled water using the heat exchanger, and does not use the heat exchanger. The normal operation which cools the cold water which flowed out from heat load equipment using at least one of the -nth refrigerators is carried out. On the other hand, when the outside air temperature is below the comparison temperature and the outside air temperature exceeds the set temperature, or when the outside air temperature is below the comparison temperature and in the intermediate period excluding summer and winter, or the outside air temperature is When the temperature is below the comparison temperature and the outside air temperature is below the set temperature, or when the outside air temperature is below the comparison temperature and in the winter, the controller uses the heat exchanger to sufficiently cool the cold water. For example, by performing a pre-cooling operation that uses both at least one refrigerator and a heat exchanger at the same time during a period when the outside air temperature is not sufficiently lowered, energy saving can be achieved during that period. By performing the free cooling operation in which the refrigerator is stopped during a period when the outside air temperature is sufficiently lowered, energy saving can be achieved during that period. By performing pre-cooling operation or free cooling operation, the heat source system can reduce energy consumption (power consumption) by performing normal operation during that period, and by performing pre-cooling operation and free cooling operation for a long period of time. , Energy saving of the system can be achieved throughout the year. In this heat source system, since the controller performs any one of normal operation, precooling operation, and free cooling operation via the outside air temperature measurement means, the chilled water temperature measurement means, and the temperature comparison means, it requires manual operation of the system. Therefore, it is possible to save labor costs and waste of time due to the need for manpower, and to ensure energy saving of the system.

The block diagram which shows an example of a heat source system. The flowchart which shows an example of each means which a heat-source system performs. Explanatory drawing of normal driving | operation. Explanatory drawing of pre-cooling operation. Explanatory drawing of free cooling driving | operation. The flowchart which shows another example of each means which a heat-source system performs.

  The details of the heat source system 10 according to the present invention will be described below with reference to the accompanying drawings such as FIG. 1 which is a configuration diagram showing an example of the heat source system 10. The heat source system 10 includes a heat load device 11 and first to third refrigerators 12 to 14 (first to nth refrigerators), a heat exchanger 15 and first to third cooling towers 16 to 18 (first To m-th cooling tower) and first to third temperature sensors 19 to 21, which are divided into a cold water circulation system and a cooling water circulation system. The system 10 is operated in each operation mode of normal operation, precooling operation, and free cooling operation described later during the operation. In the system 10, the computer 40 is operated in either one of a system automatic operation in which various operation modes are automatically performed and a system manual operation in which an operator manually switches between various operation modes.

  The heat load device 11 uses the cold water supplied thereto, for example, performs heat exchange with room air, immediately cools the room temperature to a preset target temperature, and keeps the room temperature at the target temperature during the operation. Hold. Although the detailed illustration is abbreviate | omitted, the 1st-3rd refrigerator 12-14 is a water-cooling type provided with the evaporator and the condenser, and the cold water which flowed out from the heat load apparatus 11 is separately set to predetermined temperature. Cooling. As the refrigerators 12 to 14, a compression refrigerator or an absorption refrigerator can be used. In FIG. 1, three refrigerators 12 to 14 are illustrated. However, the number of refrigerators is not limited to three, and the system 10 using two or more refrigerators is used. Can drive.

Although the detailed illustration of the heat exchanger 15 is omitted, the heat exchanger 15 includes a high-temperature side fin and a low-temperature side fin having a long-distance channel with a fine gap, and alternately places the high-temperature side fin and the low-temperature side fin alternately. It is a superposed structure, heat exchange is performed between the high temperature side fin through which the cold water flows and the low temperature side fin through which the cooling water flows, and the cold water flowing out from the heat load device 11 is replaced with the refrigerators 12 to 14 at a predetermined temperature. Cool down. The first to third cooling towers 16 to 18 cool the cooling water by bringing the outside air taken in via the blower into contact with the cooling water. The third temperature sensor 21 is installed outdoors, measures the wet bulb temperature (T ₃ ) (or dry bulb temperature) of the outside air, and outputs the measured wet bulb temperature (or dry bulb temperature) to the computer 40.

  The cold water circulation system includes the heat load device 11 and the first to third refrigerators 12 to 14, the cold water supply pipe 22, the cold water return pipe 23, the forward header 24 and the return header 25, and the cold water supply pumps 26A to 26C. 27A to 27C and valves 29 and 30 (switching mechanism). The heat load device 11 and the first to third refrigerators 12 to 13 are connected by a cold water supply pipe line 22. The forward header 24 is installed in the cold water supply line 22 extending between the heat load device 11 and the first to third refrigerators 12 to 13. The return header 25 is installed in the cold water return pipe line 23 extending between the heat load device 11 and the first to third refrigerators 12 to 13.

The cold water supply pumps 26 </ b> A to 26 </ b> C are installed in a cold water return pipe line 23 that extends between the return header 25 and the first to third refrigerators 12 to 13. The chilled water supply pumps 27 </ b> A to 27 </ b> C are installed in a chilled water supply pipeline 22 extending between the forward headers 24. The valve 29 is installed in a cold water return conduit 23 extending between the heat load device 11 and the return header 25. A bypass conduit 31 extends between the forward header 24 and the return header 25. The first temperature sensor 19 is installed in the cold water return pipe 23 that extends immediately before the heat exchanger 15 (extends after the heat load device 11 and before the heat exchanger 15), and flows into the heat exchanger 15. The temperature (T ₁ ) of the cold water immediately before (after flowing out of the heat load device 11 and immediately before flowing into the heat exchanger 15) is measured, and the measured cold water temperature is output to the computer 40.

  The cooling water circulation system is formed by first to third refrigerators 12 to 14 and first to third cooling towers 16 to 17, cooling water supply pumps 28 </ b> A to 28 </ b> C and valves 32 and 33. The first refrigerator 12 and the first cooling tower 16 are connected by a cooling water supply pipe 34A and a cooling water recovery pipe 35A. The cooling water supply pump 28 </ b> A is installed in a cooling water recovery pipe 34 </ b> A that extends between the first refrigerator 12 and the first cooling tower 16. The valve 32 is installed in a cooling water recovery pipeline 34A that extends between the first refrigerator 12 and the cooling water supply pump 28A.

  The second refrigerator 13 and the second cooling tower 17 are connected by a cooling water supply pipe 34B and a cooling water recovery pipe 35B. The cooling water supply pump 28 </ b> B is installed in a cooling water recovery pipeline 34 </ b> B that extends between the second refrigerator 13 and the second cooling tower 17. The third refrigerator 14 and the third cooling tower 18 are connected by a cooling water supply pipe 34C and a cooling water recovery pipe 35C. The cooling water supply pump 28 </ b> C is installed in a cooling water recovery pipe 34 </ b> C that extends between the third refrigerator 14 and the third cooling tower 18.

  The heat exchanger 15 is connected to the cold water circulation system and the cooling water circulation system. In the chilled water circulation system, the heat exchanger 15 is disposed between the heat load device 11 and the return header 25, and the first pipe 36 branched from the chilled water return pipe 23 and the second pipe connected to the chilled water return pipe 23. 37 to the cold water circulation system. A valve 30 is installed in the first pipeline 36. The second temperature sensor 20 is installed in the second pipe line 37 that extends immediately after the heat exchanger 15, and measures the temperature of the cold water immediately after flowing out of the heat exchanger 15.

  In the cooling water circulation system, the heat exchanger 15 is connected to the cooling water circulation system via the third pipe line 38 and the fourth pipe line 39. The third pipeline 38 is branched from a cooling water supply pipeline 34 </ b> A that extends between the first refrigerator 12 and the first cooling tower 16. The fourth pipeline 39 is connected to a cooling water recovery pipeline 35 </ b> A that extends between the first refrigerator 12 and the first cooling tower 16. A valve 33 is installed in the third pipeline 38. In this system 10, the first refrigerator 12 and the heat exchanger 15 are arranged in series with respect to the heat load device 11. Therefore, any one of the 1st refrigerator 12 and the heat exchanger 15 can also be utilized, and the 1st refrigerator 12 and the heat exchanger 15 can also be used together. In the system 10, not only the first refrigerator 12 but also the second and third refrigerators 13 and 14 are connected to heat exchangers, and the second and third refrigerators 13 and 14 and the heat exchangers are heat load devices. 11 may be arranged in series.

  The computer 40 includes a central processing unit and a memory, and has a large-capacity hard disk. An input device such as a keyboard 41 and a mouse 42 and an output device such as a display 43 and a printer (not shown) are connected to the computer 40 via an interface. When the computer 40 automatically operates the system 10, the heat load device 11, the refrigerators 12 to 14, the heat exchanger 15, the cooling towers 16 to 18, the temperature sensors 19 to 21, the pumps 26A to 26C, 27A to 27C, 28A to 28C and valves 29, 30, 32, and 33 are connected to the computer 40 via an interface (not shown).

The central processing unit of the computer 40 activates an application program stored in the memory based on control by the operating system, and executes the following means according to the application program. The central processing unit executes wet bulb temperature measurement means (outside air temperature measurement means) that measures the wet bulb temperature (T ₃ ) of the outside air using the third temperature sensor 21 (during system automatic operation), and a heat exchanger The first temperature sensor 19 is used to determine the chilled water temperature (T ₁ ) (first chilled water temperature) immediately before flowing into the heat exchanger 15 (just after flowing out from the heat load device 11 and immediately before flowing into the heat exchanger 15). Measure the cold water temperature measurement means (during system automatic operation). In the operation of the system 10 shown in FIG. 6 which will be described later, the central processing unit performs the cold water temperature of the cold water immediately after flowing out of the heat exchanger 15 in addition to the wet bulb temperature measuring means and the cold water temperature measuring means (first cold water temperature measuring means). The second cold water temperature measuring means for measuring (T ₂ ) (second cold water temperature) using the second temperature sensor 20 is executed. The central processing unit executes dry bulb temperature measurement means (outside air temperature measurement means) that measures the dry bulb temperature of the outside air using the third temperature sensor 21 instead of the wet bulb temperature (T ₃ ) of the outside air. In some cases.

In the operation of the system 10 shown in FIG. 2, which will be described later, the central processing unit of the computer 40 compares the wet bulb temperature output from the third temperature sensor 21 (or the dry bulb corrected temperature obtained by subtracting a predetermined value from the dry bulb temperature). The temperature comparison means for comparing the temperature is executed (during system automatic operation). Comparison temperature, the cold water temperature immediately before flowing into the heat exchanger 15 (T ₁₎ a preset temperature (first temperature sensor 19 chilled water temperature output from) (T _S1) a reduced temperature (T ₁ -T _S1 ). In the system manual operation, the operator reads the wet bulb temperature (T ₃ ) of the outside air (or the dry bulb temperature (T ₃ ) of the outside air) from the third temperature sensor 21, and the cold water temperature (T ₃ ) from the first temperature sensor 19. ₁ ) is read, and a preset temperature (T _S1 ) is subtracted from the cold water temperature (T ₁ ) to calculate a comparative temperature (T ₁ -T _S1 ). Further, the operator compares the wet bulb temperature (T ₃ ) (or the dry bulb corrected temperature obtained by subtracting a predetermined value from the dry bulb temperature) with the comparison temperature (T ₁ −T _S1 ).

In the operation of the system 10 shown in FIG. 2, the central processing unit of the computer 40 compares the wet bulb temperature (T ₃ ) (or dry bulb corrected temperature) with the comparative temperature (T ₁ -T _S1 ). When (or dry bulb correction temperature) exceeds the comparison temperature, normal operation execution means for executing normal operation is executed (during system automatic operation), and the wet bulb temperature (or dry bulb correction temperature) is below the comparison temperature. Then, the pre-cooling operation execution means or the free cooling operation execution means for performing any one of the pre-cooling operation and the free cooling operation is executed (during system automatic operation). In the manual operation of the system, the operator compares the wet bulb temperature (T ₃ ) (or dry bulb correction temperature) with the comparison temperature (T ₁ -T _S1 ). As a result, the wet bulb temperature (or dry bulb correction temperature) If the temperature exceeds the comparison temperature, normal operation is performed. Further, in the system manual operation, the operator compares the wet bulb temperature (T ₃ ) (or dry bulb correction temperature) with the comparison temperature (T ₁ -T _S1 ), and as a result, the wet bulb temperature (or dry bulb correction temperature). When is below the comparison temperature, either the pre-cooling operation or the free cooling operation is performed.

In the operation of the system 10 shown in FIG. 6, the central processing unit of the computer 40 determines the wet bulb temperature (or dry bulb corrected temperature obtained by subtracting a predetermined value from the dry bulb temperature) output from the third temperature sensor 21 and the comparison temperature. The temperature first comparing means for comparing the two is executed (during system automatic operation). The central processing unit performs normal operation when the wet bulb temperature (or dry bulb correction temperature) exceeds the comparison temperature as a result of comparing the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature. Execute the means (during system automatic operation). In the system manual operation, the operator reads the wet bulb temperature (T ₃ ) of the outside air from the third temperature sensor 21, reads the cold water temperature (T ₁ ) from the first temperature sensor 19, and the cold water temperature (T ₁ ). A preset temperature (T _S1 ) set in advance is subtracted from the above to calculate a comparative temperature (T ₁ -T _S1 ). Further, the operator compares the wet bulb temperature (T ₃ ) (or the dry bulb corrected temperature obtained by subtracting a predetermined value from the dry bulb temperature) with the comparison temperature (T ₁ −T _S1 ). In the system manual operation, the operator compares the wet bulb temperature (T ₃ ) (or dry bulb correction temperature) with the comparison temperature (T ₁ -T _S1 ). As a result, the wet bulb temperature (or dry bulb correction temperature) is compared. If the temperature is exceeded, perform normal operation.

In the operation of the system 10 shown in FIG. 6, the central processing unit of the computer 40 compares the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature. As a result, the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature. In this case, a temperature second comparing means for comparing the cold water temperature (T ₂ ) (second cold water temperature) output from the second temperature sensor 20 with the second set temperature is executed (during system automatic operation). In the manual operation of the system, the operator compares the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature, and if the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature, the second temperature sensor The second cold water temperature (T ₂ ) is read from 20, and the read second cold water temperature (T ₂ ) is compared with the second set temperature.

  In the operation of the system 10 shown in FIG. 6, the central processing unit of the computer 40 performs the pre-cooling operation when the second chilled water temperature exceeds the second set temperature as a result of comparing the second chilled water temperature and the second set temperature. The pre-cooling operation execution means is executed (during system automatic operation). When the second cold water temperature is equal to or lower than the second set temperature, the central processing unit executes free cooling operation performing means for performing the free cooling operation (during system automatic operation). In addition, in the system manual operation, as a result of comparing the second cold water temperature and the second set temperature, the operator performs a pre-cool operation when the second cold water temperature exceeds the second set temperature, and the second cold water temperature is 2 If the temperature is lower than the preset temperature, perform free cooling operation.

FIG. 2 is a flowchart illustrating an example of each unit performed by the heat source system 10, and FIG. 3 is an explanatory diagram of normal operation. FIG. 4 is an explanatory diagram of the pre-cooling operation, and FIG. 5 is an explanatory diagram of the free cooling operation. 3 to 5, a pipeline through which cold water or cooling water flows in each operation mode is indicated by a solid line, and a pipeline through which cold water or cooling water does not flow is indicated by a dotted line. 3 to 5, illustration of the computer 40 is omitted. A set temperature (T _S1 ) is stored in the hard disk of the computer 40. Setting temperature is 0 degreeC or more, Preferably it is 0-5 degreeC, More preferably, it is 2-3 degreeC. The set temperature can be arbitrarily set and changed via the input device.

Based on FIG. 2, an example of the operation of the system 10 based on the system automatic operation by the computer 40 will be described as follows. When the system 10 is turned on, the computer 40, the heat load device 11, the refrigerators 12 to 14, the heat exchanger 15, the cooling towers 16 to 18, the temperature sensors 19 to 21, the pumps 26A to 26C, 27A to 27C, and 28A to 28C. The valves 29, 30, 32, and 33 are activated. In the operation of the system 10 shown in FIG. 2, the first and third temperature sensors 19 and 21 are operated, and the second temperature sensor 20 is not operated. Therefore, the cold water temperature (T ₂ ) (second cold water temperature) immediately after flowing out of the heat exchanger 15 is not measured.

  When the system 10 is activated, the computer 40 operates the system 10 in the normal operation mode (S-1). In the cooling water circulation system in normal operation, the computer 40 holds the valve 32 in the open state and holds the valve 33 in the closed state. The computer 40 operates the pumps 26A to 26C, 27A to 27C, 28A to 28C, the refrigerators 12 to 14, and the cooling towers 16 to 18, and stops the operation of the heat exchanger 15. As shown by arrows in FIG. 3, the cooling water is supplied from the cooling towers 16 to 18 through the cooling water supply paths 34A to 34C to the refrigerators 12 to 14 by the outputs of the pumps 28A to 28C, and the refrigerators 12 to 14 are supplied. To the cooling towers 16 to 18 through the cooling water recovery paths 35A to 35C.

  The cooling water is cooled in the cooling towers 16 to 18, and then supplied again to the refrigerators 12 to 14 through the cooling water supply paths 34A to 34C. The temperature rises in the refrigerators 12 to 14, and the cooling water is recovered again. It returns to the cooling towers 16-18 through the paths 35A-35C. In normal operation, in the cooling water circulation system, the cooling water circulates between the cooling towers 16 to 18 and the refrigerators 12 to 14.

  In the cold water circulation system in normal operation, the computer 40 holds the valve 29 in the open state and holds the valve 30 in the closed state. The chilled water flows from the refrigerators 12 to 14 through the chilled water supply path 22 to the forward header 24 by the outputs of the pumps 26A to 26C and 27A to 27C, merges in the forward header 24, and then passes through the chilled water supply path 22 to generate heat. Supplied to the load device 11. The cold water whose temperature has risen in the heat load device 11 flows out from the heat load device 11, then flows into the return header 25 through the cold water return path 23, is divided in the return header 25, and then passes through the cold water return path 23. Return to each refrigerator 12-14.

  After the chilled water is cooled in the refrigerators 12 to 14, the chilled water is supplied again to the heat load device 11 through the chilled water supply path 22, the temperature rises in the heat load device 11, and is refrigerated again through the chilled water return path 23. Return to machine 12-14. In normal operation, the cooling water circulates between the refrigerators 12 to 14 and the heat load device 11 in the cold water circulation system.

  In the normal operation shown in FIG. 3, the first to third refrigerators 12 to 14 and the first to third cooling towers 16 to 18 are operating, but all the refrigerators depend on the required load amount of the heat load device 11. It is not necessary to operate the 12-14 and the cooling towers 16-18, and at least the first refrigerator 12 and the first cooling among the first to third refrigerators 12-14 and the first to third cooling towers 16-18. The tower 16 can be operated for normal operation. In addition, when the required load amount of the heat load device 11 is reduced while the first to third refrigerators 12 to 14 are operating, a part of the cold water flowing out from the device 11 is returned and divided from the header 25 to the bypass pipe 31. In some cases, the required load amount of the device 11 can be handled without stopping the refrigerators 12 to 14.

  The computer 40 measures the wet bulb temperature (or dry bulb temperature) of the outside air through the third temperature sensor 21 while performing normal operation (S-2) (wet bulb temperature measuring means or dry bulb temperature measuring means). ) (Outside air temperature measuring means), the temperature of the cold water immediately before flowing into the heat exchanger 15 via the first temperature sensor 19 (after flowing out of the heat load device 11 and immediately before flowing into the heat exchanger 15) ( First cold water temperature) is measured (S-3) (cold water temperature measuring means). During operation of the system 10, the third temperature sensor 21 continuously measures the wet bulb temperature (or dry bulb temperature), outputs the measured wet bulb temperature (or dry bulb temperature) to the computer 40, and The temperature sensor 19 continuously measures the chilled water temperature and outputs the measured chilled water temperature to the computer 40.

The computer 40 compares the wet bulb temperature (T ₃ ) output from the third temperature sensor 21 (or the dry bulb corrected temperature obtained by subtracting a predetermined value from the dry bulb temperature) with the comparison temperature (T ₁ −T _S1 ). (S-4) (temperature comparison means). As a result of comparing the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature, the computer 40 determines that the wet bulb temperature (or dry bulb correction temperature) exceeds the comparison temperature (T ₃ > T ₁ −T _S1 ). Then, the normal operation is continued (S-5) (normal operation execution means). The computer 40 determines whether to stop the operation of the system 10 (S-7), and when continuing the operation of the system 10, returns to step 2 (S-2) and repeats the procedure from step 2. When stopping the operation of the system 10 in step 7 (S-7), the computer 40 turns off the system 10.

As a result of comparing the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature in step 4 (S-4), the computer 40 determines that the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature (T ₃ ≦ T ₁₋ T _S1 ), normal operation is stopped, precooling operation is performed (S-6) (precooling operation execution means), or free cooling operation is performed (S-6) (free cooling). Driving execution means).

  In the cooling water circulation system in the pre-cooling operation, the computer 40 holds the valve 33 in the open state and holds the valve 32 in the closed state. The computer 40 operates the pumps 28 </ b> A to 28 </ b> C, the refrigerators 13 and 14, the cooling towers 16 to 18, and the heat exchanger 15, and stops the operation of the first refrigerator 12. As indicated by arrows in FIG. 4, the cooling water is supplied from the cooling tower 16 through the third pipe 38 to the heat exchanger 15 by the output of the pump 28A, and from the heat exchanger 15 through the fourth pipe 39. Return to the cooling tower 16. After the cooling water is cooled in the cooling tower 16, it is supplied again to the heat exchanger 15 through the third pipe 38, the temperature rises in the heat exchanger 15, and is cooled again through the fourth pipe 39. Return to Tower 16. In the cooling water circulation system in the pre-cooling operation, the cooling water circulates through the cooling tower 16 and the heat exchanger 15.

  In the cooling water circulation system, the cooling water is supplied from the cooling towers 17 and 18 to the refrigerators 13 and 14 through the cooling water supply paths 34B and 34C by the outputs of the pumps 28B and 28C, and the cooling water from the refrigerators 13 and 14 is supplied. It returns to the cooling towers 17 and 18 through the recovery paths 35B and 35C. The cooling water is cooled in the cooling towers 17 and 18, and then supplied again to the refrigerators 13 and 14 through the cooling water supply paths 34B and 34C. The temperature rises in the refrigerators 13 and 14, and the cooling water is recovered again. It returns to the cooling towers 17 and 18 through the paths 35B and 35C. In the cooling water circulation system in the pre-cooling operation, the cooling water circulates between the cooling towers 17 and 18 and the refrigerators 13 and 14.

  In the cold water circulation system in the pre-cooling operation, the computer 40 holds the valve 30 in the open state and holds the valve 29 in the closed state. The computer 40 operates the pumps 26B, 26C, 27B, and 27C, and stops the operation of the pumps 26A and 27A. The chilled water flows from the refrigerators 13 and 14 through the chilled water supply path 22 to the forward header 24 by the outputs of the pumps 27B and 27C, merges at the forward header 24, and then passes through the chilled water supply path 22 to the heat load device 11. Supplied. The cold water whose temperature has risen in the heat load device 11 flows out of the heat load device 11, then flows into the heat exchanger 15 from the cold water return path 23 through the first pipe 36, and is cooled in the heat exchanger 15. . The cold water flowing out from the heat exchanger 15 flows into the recovery header 25 from the second pipe 37 through the cold water return path 23, and after being diverted in the return header 25, passes through the cold water return path 23 to the second and second chilled water. 3 Return to refrigerators 13 and 14.

  After the chilled water is cooled in the refrigerators 13 and 14, the chilled water is supplied again to the thermal load device 11 through the chilled water supply path 22, the temperature rises in the thermal load apparatus 11, and again passes through the first pipeline 36. After flowing into the heat exchanger 15, it returns to the refrigerators 13 and 14 through the cold water return path 23. In the cold water circulation system in the pre-cooling operation, the cooling water circulates through the refrigerators 13, 14, the heat load device 11, and the heat exchanger 15. In the precooling operation shown in FIG. 4, the second and third refrigerators 13 and 14 and the second and third cooling towers 17 and 18 are operating. It is not necessary to operate the three refrigerators 13 and 14 and the second and third cooling towers 17 and 18, and at least the second and third refrigerators 13 and 14 and the second and third cooling towers 17 and 18 are at least first. The precooling operation can be performed by operating the two refrigerators 13 and the second cooling tower 17.

  In the pre-cooling operation, after the chilled water circulating in the chilled water circulation system is cooled in the heat exchanger 15, the chilled water returns to the refrigerators 13 and 14, so that the chilled water is compared with the chilled water that does not pass through the heat exchanger 15. Cold water can be cooled in a state where the temperature is low and the output is suppressed in the refrigerators 13 and 14, and the load on the refrigerators 13 and 14 and the cooling towers 17 and 18 can be reduced.

  In the cooling water circulation system in the free cooling operation, the computer 40 holds the valve 33 in the open state and holds the valve 32 in the closed state. The computer 40 operates the heat exchanger 15, the cooling tower 16, and the pump 28A, and stops the operation of the first to third refrigerators 12 to 14, the second and third cooling towers 17 and 18, and the pumps 28B and 28C. .

  As indicated by arrows in FIG. 5, the cooling water is supplied from the cooling tower 16 to the heat exchanger 15 through the third pipe 38 by the output of the pump 28A, and from the heat exchanger 15 through the fourth pipe 39. Return to the cooling tower 16. After the cooling water is cooled in the cooling tower 16, it is supplied again to the heat exchanger 15 through the third pipe 38, the temperature rises in the heat exchanger 15, and is cooled again through the fourth pipe 39. Return to Tower 16. In the cooling water circulation system in the free cooling operation, the cooling water circulates through the cooling tower 16 and the heat exchanger 15.

  In the chilled water circulation system in the free cooling operation, the computer 40 holds the valve 30 in the open state and holds the valve 29 in the closed state. The computer 40 operates the pumps 26A, 27A and stops the operation of the pumps 26B, 26C, 27B, 27C. The cold water flows from the first refrigerator 12 (during stop) through the cold water supply path 22 into the supply header 24 by the outputs of the pumps 26A and 27A, and from the supply header 24 through the cold water supply path 22 to the heat load device 11. Supplied.

  The cold water whose temperature has risen in the heat load device 11 flows out from the heat load device 11, then flows into the heat exchanger 15 from the cold water recovery path 23 through the first pipe 36, and is cooled in the heat exchanger 15. . The cold water flowing out from the heat exchanger 15 flows into the return header 25 from the second pipe 37 through the cold water return path 23, and returns from the return header 25 through the cold water return path 23 to the refrigerator 12. The chilled water is supplied again to the heat load device 11 through the chilled water supply passage 22, the temperature rises in the heat load device 11, flows into the heat exchanger 15 again through the first pipe 36, and then returns to the chilled water. It returns to the refrigerator 12 through the path 23. In the free water cooling operation, the cooling water circulates between the heat load device 11 and the heat exchanger 15 in the cold water circulation system.

  In the free cooling operation, the cold water circulating in the cold water circulation system is cooled in the heat exchanger 15, and the cold water is supplied to the heat load device 11. In the free cooling operation, since the cold water is cooled only by the outside air without operating the refrigerators 12 to 14, the output (power consumption) in the refrigerators 12 to 14 can be reduced to 0, and the cooling tower 17 , 18 (power consumption) can be made zero.

  In step 7 (S-7), the computer 40 determines whether to stop the operation of the system 10, and when continuing the operation of the system 10, returns to step 2 (S-2) and repeats the procedure from step 2. . When stopping the operation of the system 10 in step 7 (S-7), the computer 40 turns off the system 10. When the computer 40 determines that the wet bulb temperature is equal to or lower than the comparison temperature in step 4 (S-4), the computer 40 continues the precooling operation (S-6) (precooling operation execution means) or the free cooling operation. (S-6) (free cooling operation execution means).

As an example of the case where the computer 40 selects either the precooling operation or the free cooling operation in step 6 (S-6), is the outside air temperature (T ₃ ) suitable for the precooling operation or the free cooling operation? Judging. In this case, the computer 40 compares the outside air temperature output from the third temperature sensor 21 with a preset temperature stored in the hard disk in advance, and performs a pre-cooling operation when the outside air temperature (T ₃ ) exceeds the preset temperature. When the outside air temperature (T ₃ ) is lower than the set temperature, the free cooling operation is performed. Note that the set temperature can be arbitrarily set and changed via the input device.

  As another example of the case where the computer 40 selects either the pre-cooling operation or the free cooling operation in step 6 (S-6), the computer 40 determines whether the current operating day of the system 10 is an intermediate period. If it is an intermediate period, a pre-cooling operation is performed, and if it is not an intermediate period, a free cooling operation is performed. The intermediate period is a period excluding summer and winter, for example, and is stored in the hard disk of the computer 40 in advance. The intermediate period can be arbitrarily set and changed via the input device.

In the system manual operation, the operator reads the wet bulb temperature (T ₃ ) (or dry bulb temperature) of the outside air from the third temperature sensor 21, reads the cold water temperature (T ₁ ) from the first temperature sensor 19, and the cold water temperature. calculating the _{(T 1)} predetermined from set point temperature _{(T S1)} a reduced and comparison temperature _(T 1 _{-T S1).} Further, the operator compares the wet bulb temperature (T ₃ ) (or the dry bulb corrected temperature obtained by subtracting a predetermined value from the dry bulb temperature) with the comparison temperature (T ₁ −T _S1 ). The operator performs normal operation of the system 10 when the wet bulb temperature (or dry bulb correction temperature) exceeds the comparison temperature as a result of comparing the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature. . In normal operation, the operator opens the valve 32 in the cooling water circulation system, closes the valve 33, opens the valve 29 in the cold water circulation system, and closes the valve 30. The operator continues normal operation as long as the wet bulb temperature exceeds the comparison temperature.

Further, in the system manual operation, the operator compares the wet bulb temperature (T ₃ ) (or dry bulb correction temperature) with the comparison temperature (T ₁ -T _S1 ), and as a result, the wet bulb temperature (or dry bulb correction temperature). When is below the comparative temperature, either precooling operation or free cooling operation is performed. The selection of either the pre-cooling operation or the free cooling operation is determined by the operator based on various conditions such as the operating day of the system and the outside air temperature. In the pre-cooling operation, the operator opens the valve 33 in the cooling water circulation system, closes the valve 32, opens the valve 30 in the cold water circulation system, and closes the valve 29. In the free cooling operation, the operator opens the valve 33 in the cooling water circulation system, closes the valve 32, opens the valve 30 in the cold water circulation system, and closes the valve 29. As long as the wet bulb temperature is equal to or lower than the comparison temperature, the operator continues the precooling operation or the free cooling operation.

  In the heat source system 10, since the first refrigerator 12 and the heat exchanger 15 are arranged in series with respect to the heat load device 11, both the first refrigerator 12 and the heat exchanger 15 are used simultaneously. It is possible to perform a precooling operation that reduces the load on the second and third refrigerators 13 and 14 by using the precooled cold water while precooling the cold water using the heat exchanger 15 in advance. Accordingly, the heat source system 10 performs the normal operation during the period by performing the pre-cooling operation or the free cooling operation in a period in which the outside air temperature is not sufficiently decreased (for example, an intermediate period excluding summer and winter). Energy consumption (power consumption) can be reduced, and energy saving can be achieved during that period. The heat source system 10 performs the free cooling operation during a period in which the outside air temperature is sufficiently lowered (for example, in winter), thereby reducing the outputs (power consumption) of the first to third refrigerators 12 to 14 during that period. It is possible to save energy during that period. The heat source system 10 can achieve energy saving of the system 10 throughout the year by performing precooling operation and free cooling operation for a long period of time.

  The heat source system 10 does not use the heat exchanger 15 because the cold water cannot be sufficiently cooled using the heat exchanger 15 when the wet bulb temperature (or dry bulb correction temperature) exceeds the comparative temperature. In addition, a normal operation for cooling the cold water flowing out from the heat load device 11 is performed using at least one of the first to third refrigerators 12 to 14. On the other hand, when the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparative temperature, the cold water can be sufficiently cooled using the heat exchanger 15, and therefore, for example, the outside air temperature is not sufficiently lowered. A precooling operation using at least one of the second refrigerator 13 and the third refrigerator 14 and the heat exchanger 15 at the same time or using the heat exchanger 15 without operating the first to third refrigerators 12-14. By performing the free cooling operation, energy saving of the system 10 can be reliably achieved during that period.

FIG. 6 is a flowchart illustrating another example of each unit performed by the heat source system 10. In addition, FIGS. 3-5 is used for normal driving | operation, precooling driving | operation, and free cooling driving | operation. The hard disk of the computer 40 stores the first set temperature (T _S1 ) and the second set temperature (T _S2 ). 1st preset temperature is 0 degreeC or more, Preferably it is 0-5 degreeC, More preferably, it is 2-3 degreeC. The second set temperature is 5 ° C. or higher. The second set temperature (T _S2 ) is preferably the water supply set temperature (for example, 7 ° C.) of the refrigerators 12 to 14. The second set temperature can be arbitrarily set and changed via the input device.

  Based on FIG. 6, another example of the operation of the system 10 based on the automatic system operation by the computer 40 will be described as follows. When the system 10 is turned on, the computer 40, the heat load device 11, the refrigerators 12 to 14, the heat exchanger 15, the cooling towers 16 to 18, the temperature sensors 19 to 21, the pumps 26A to 26C, 27A to 27C, and 28A to 28C. The valves 29, 30, 32, and 33 are activated. In the operation of the system 10 shown in FIG. 6, the second temperature sensor 20 is operated together with the first and third temperature sensors 19 and 21, unlike that of FIG. 2.

  When the system 10 is activated, the computer 40 operates the system 10 in the normal operation mode (S-10). The computer 40 holds the valves 29 and 32 in the open state and holds the valves 30 and 33 in the closed state. In normal operation, in the cooling water circulation system, the cooling water circulates between the cooling towers 16 to 18 and the refrigerators 12 to 14. In normal operation, the cooling water circulates between the refrigerators 12 to 14 and the heat load device 11 in the cold water circulation system. Since the normal operation is the same as that described with reference to FIG. 3, the detailed description thereof will be omitted by using FIG.

  The computer 40 measures the wet bulb temperature (or dry bulb temperature) of the outside air through the third temperature sensor 21 while performing normal operation (S-11) (wet bulb temperature measuring means or dry bulb temperature measuring means). ) (Outside air temperature measuring means), the temperature of the cold water immediately before flowing into the heat exchanger 15 via the first temperature sensor 19 (after flowing out of the heat load device 11 and immediately before flowing into the heat exchanger 15) ( (First chilled water temperature) is measured (S-12) (first chilled water temperature measuring means), and the temperature of the chilled water immediately after flowing out of the heat exchanger 15 through the second temperature sensor 20 (second chilled water temperature) is determined. Measure (S-13) (second cold water temperature measuring means).

  During the operation of the system 10, the third temperature sensor 21 continuously measures the wet bulb temperature (or dry bulb temperature), outputs the measured wet bulb temperature (or dry bulb temperature) to the computer 40, and the first temperature sensor. 19 continuously measures the first cold water temperature, outputs the measured first cold water temperature to the computer 40, and the second temperature sensor 20 continuously measures the second cold water temperature, and measures the second cold water temperature. Is output to the computer 40. In normal operation, although the cold water does not flow through the second pipe 37 and the second temperature sensor 20 is in operation, the computer 40 outputs the cold water temperature (the first temperature output from the second temperature sensor 20). (2 cold water temperature) is ignored.

The computer 40 compares the wet bulb temperature (T ₃ ) output from the third temperature sensor 21 (or the dry bulb corrected temperature obtained by subtracting a predetermined value from the dry bulb temperature) with the comparison temperature (T ₁ −T _S1 ). (S-14) (temperature first comparison means). As a result of comparing the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature, the computer 40 determines that the wet bulb temperature (or dry bulb correction temperature) exceeds the comparison temperature (T ₃ > T ₁ −T _S1 ). Then, the normal operation is continued (S-15) (normal operation execution means). The computer 40 determines whether to stop the operation of the system 10 (S-16). When the operation of the system 10 is continued, the process returns to step 11 (S-11) and the procedure from step 11 is repeated. When stopping the operation of the system 10 in step 16 (S-16), the computer 40 turns off the system 10.

As a result of comparing the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature in step 14 (S-14), the computer 40 determines that the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature (T ₃ ≦ T ₁₋ T _S1 ), the normal operation is stopped and the pre-cooling operation is performed (S-17) (pre-cooling operation executing means). The computer 40 holds the valves 30 and 33 in the open state and holds the valves 29 and 32 in the closed state. In the cooling water circulation system in the pre-cooling operation, the cooling water circulates through the cooling tower 16 and the heat exchanger 15, and the cooling water circulates through the cooling towers 17 and 18 and the refrigerators 13 and 14. In the cold water circulation system in the pre-cooling operation, cold water circulates through the refrigerators 13 and 14, the heat load device 11, and the heat exchanger 15. Since the pre-cooling operation is the same as that described with reference to FIG. 4, the detailed description thereof will be omitted by using FIG.

The computer 40 compares the second cold water temperature (T ₂ ) output from the second temperature sensor 20 with the second set temperature (T _S2 ) while performing the pre-cooling operation (S-18) (Temperature second Comparison means). When the computer 40 determines that the second chilled water temperature exceeds the second set temperature (T ₂ > T _S2 ) as a result of comparing the second chilled water temperature with the second set temperature, the pre-cooling operation is continuously performed ( S-19) (Precooling operation execution means). The computer 40 determines whether to stop the operation of the system 10 (S-16). When the operation of the system 10 is continued, the process returns to step 11 (S-11) and the procedure from step 11 is repeated.

As a result of returning to step 11 (S-11) and comparing the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature, the computer 40 determines that the wet bulb temperature (or dry bulb correction temperature) exceeds the comparison temperature (T _If it is determined that ₃ > T ₁ −T _S1 ), the pre-cooling operation is stopped and the normal operation is performed (normal operation execution means) (S-15). When stopping the operation of the system 10 in step 16 (S-16), the computer 40 turns off the system 10.

When the computer 40 determines that the second chilled water temperature is equal to or lower than the second set temperature (T ₂ ≦ T _S2 ) as a result of comparing the second chilled water temperature with the second set temperature in Step 18 (S-18), The precooling operation is stopped and the free cooling operation is performed (S-20) (free cooling operation execution means). The computer 40 holds the valves 30 and 33 in the open state and holds the valves 29 and 32 in the closed state. In the cooling water circulation system in the free cooling operation, the cooling water circulates between the cooling tower 16 and the heat exchanger 15, and in the cooling water circulation system in the free cooling operation, the cold water circulates through the heat load device 11 and the heat exchanger 15. Since the free cooling operation is the same as that described in FIG. 5, the detailed description thereof is omitted by using FIG.

The computer 40 determines whether to stop the operation of the system 10 (S-21). When the operation of the system 10 is continued, the process returns to step 18 (S-18) and the procedure from step 18 is repeated. In this case, the computer 40 compares the second cold water temperature with the second set temperature while continuously performing the free cooling operation (S-18) (temperature second comparison means), and the second cold water temperature is the first. When it is determined that the temperature is equal to or lower than 2 set temperatures (T ₂ ≦ T _S2 ), the free cooling operation is continued (S-20) (free cooling operation execution means). Conversely, if it is determined that the second cold water temperature exceeds the second set temperature (T ₂ > T _S2 ), the free cooling operation is stopped and the pre-cooling operation is performed (S-19) (pre-cooling operation executing means). When stopping the operation of the system 10 in step 21 (S-21), the computer 40 turns off the system 10.

In the system manual operation, the operator reads the wet bulb temperature (T ₃ ) (or dry bulb temperature) of the outside air from the third temperature sensor 21, reads the first cold water temperature (T ₁ ) from the first temperature sensor 19, and The second cold water temperature (T ₂ ) is read from the second temperature sensor 20. The operator calculates a comparative temperature (T ₁ -T _S1 ) by subtracting a preset temperature (T _S1 ) from the cold water temperature (T ₁ ), and calculates the wet bulb temperature (T ₃ ) (or the dry bulb temperature). The dry-bulb correction temperature obtained by subtracting a predetermined value is compared with the comparison temperature (T ₁ -T _S1 ).

In the system manual operation, the operator compares the wet bulb temperature (or dry bulb correction temperature) with the comparison temperature. As a result, the wet bulb temperature (or dry bulb correction temperature) exceeds the comparison temperature (T ₃ > T ₁ −T _{If S1} ), normal operation of the system 10 is performed. In normal operation, the operator opens the valve 32 in the cooling water circulation system, closes the valve 33, opens the valve 29 in the cold water circulation system, and closes the valve 30. The operator continues normal operation as long as the wet bulb temperature exceeds the comparison temperature.

In the system manual operation, when the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature (T ₃ ≦ T ₁ −T _S1 ), the operator can set the second cold water temperature (T ₂ ) and the second set temperature ( T _S2 ). When the operator compares the second chilled water temperature (T ₂ ) with the second set temperature (T _S2 ) and the second chilled water temperature exceeds the second set temperature (T ₂ > T _S2 ), the system 10 Perform pre-cooling operation. In the pre-cooling operation, the operator opens the valve 33 in the cooling water circulation system, closes the valve 32, opens the valve 30 in the cold water circulation system, and closes the valve 29. The operator continues the pre-cooling operation as long as the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature and the second cold water temperature exceeds the second set temperature.

In the system manual operation, as a result of comparing the second cold water temperature (T ₂ ) and the second set temperature (T _S2 ), the second cold water temperature is equal to or lower than the second set temperature (T ₂ ≦ T _S2 ). In this case, a free cooling operation of the system 10 is performed. In the free cooling operation, the operator opens the valve 33 in the cooling water circulation system, closes the valve 32, opens the valve 30 in the cold water circulation system, and closes the valve 29. The operator continues the free cooling operation as long as the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature and the second cold water temperature is equal to or lower than the second set temperature.

  In the heat source system 10, since the first refrigerator 12 and the heat exchanger 15 are arranged in series with respect to the heat load device 11, both the first refrigerator 12 and the heat exchanger 15 are used simultaneously. It is possible to perform a precooling operation that reduces the load on the second and third refrigerators 13 and 14 by using the precooled cold water while precooling the cold water using the heat exchanger 15 in advance. Therefore, the heat application system 10 can perform a pre-cooling operation in a period in which the outside air temperature is not sufficiently lowered (for example, an intermediate period excluding summer and winter), and energy consumption by performing normal operation in that period. (Power consumption) can be reduced, and energy can be saved during that period. The heat source system 10 performs the free cooling operation during a period in which the outside air temperature is sufficiently lowered (for example, in winter), thereby reducing the outputs (power consumption) of the first to third refrigerators 12 to 14 during that period. It is possible to save energy during that period. The heat source system 10 can achieve energy saving of the system 10 throughout the year by performing precooling operation and free cooling operation for a long period of time.

  The heat source system 10 does not use the heat exchanger 15 because the cold water cannot be sufficiently cooled using the heat exchanger 15 when the wet bulb temperature (or dry bulb correction temperature) exceeds the comparative temperature. In addition, a normal operation for cooling the cold water flowing out from the heat load device 11 is performed using at least one of the first to third refrigerators 12 to 14. On the other hand, when the wet bulb temperature (or dry bulb correction temperature) is equal to or lower than the comparison temperature, the second cold water temperature is compared with the second set temperature, and when the second cold water temperature exceeds the second set temperature, the heat exchanger 15 can be used to cool the cold water, so the pre-cooling operation is continued. Further, when the second cold water temperature is equal to or lower than the second set temperature, the heat exchanger 15 can be used to sufficiently cool the cold water, so the heat exchanger 15 is used without operating the refrigerators 12 to 14. Perform free cooling operation. The heat source system 10 performs the pre-cooling operation in a period in which the outside air temperature is not sufficiently lowered, so that energy saving can be reliably achieved in the period, and free cooling is performed in the period in which the outside air temperature is sufficiently lowered. By performing the operation, it is possible to reliably save energy during that period.

DESCRIPTION OF SYMBOLS 10 Heat source system 11 Heat load apparatus 12 1st refrigerator 13 2nd refrigerator 14 3rd refrigerator 15 Heat exchanger 16 1st cooling tower 17 2nd cooling tower 18 3rd cooling tower 19 1st temperature sensor 20 2nd temperature Sensor 21 Third temperature sensor 22 Chilled water supply pipe 23 Chilled water return pipe 26A-26C Chilled water supply pump 27A-27C Chilled water supply pump 28A-28C Cooling water supply pump 29 Valve (switching mechanism)
30 Valve (switching mechanism)
32 Valve (switching mechanism)
33 Valve (switching mechanism)
34A to 34C Cooling water supply pipe 35A to 35C Cooling water recovery pipe 36 First pipe 37 Second pipe 38 Third pipe 39 Fourth pipe 40 Computer (control device)

Claims (6)

Instead of a heat load device using cold water, a first to nth refrigerator that individually cools the cold water flowing out of the heat load device, and at least a first refrigerator of the first to nth refrigerators. Cooling the cooling water supplied to at least one of the first to n-th refrigerators and the heat exchanger via a predetermined switching mechanism. First to m-th cooling towers, and when the state of the outside air is a predetermined condition, the operation of the first to n-th refrigerators is stopped and the cooling water supplied to the heat exchanger is In the heat source system for performing a free cooling operation for cooling the cold water flowing out from the heat load device using the heat exchanger while cooling by a cooling tower,
At least the first refrigerator of the first to nth refrigerators and the heat exchanger are arranged in series with respect to the heat load device, and in the heat source system, immediately before flowing into the heat exchanger. A comparison temperature, which is a temperature obtained by subtracting a preset temperature from the cold water temperature of the cold water, is compared with the outside air temperature, and when the outside air temperature exceeds the comparison temperature, the cooling water supplied to the refrigerator is Normal operation of cooling the cold water flowing out from the heat load device using at least one of the first to n-th refrigerators without using the heat exchanger while cooling by the cooling tower. When the outside air temperature is equal to or lower than the comparison temperature and the outside air temperature exceeds the set temperature, the operation of at least the first refrigerator of the first to nth refrigerators is stopped and stopped. The remaining freezer except for the freezer While cooling the cooling water supplied to at least one of them and the heat exchanger by the cooling tower, precooling the cold water flowing out from the heat load device using the heat exchanger and stopping the refrigeration A pre-cooling operation is performed to cool the cold water flowing out from the heat load device using at least one of the remaining refrigerators excluding the machine, and the outside air temperature is equal to or lower than the comparison temperature. When the temperature is equal to or lower than the set temperature, the free cooling operation is performed.   The heat source system includes a control device that performs any one of the normal operation, the precooling operation, and the free cooling operation, and the control device includes an outside air temperature measurement unit that measures an outside air temperature, and the heat exchanger. Cold water temperature measuring means for measuring the cold water temperature of the cold water immediately before flowing in, and temperature comparison means for comparing the measured outside air temperature with the comparison temperature, and the control device is configured to compare the outside air temperature with the comparison. When the temperature exceeds, the normal operation is performed, and when the outside air temperature is equal to or lower than the comparison temperature and the outside air temperature exceeds the set temperature, the pre-cooling operation is performed, and the outside air temperature is The heat source system according to claim 1, wherein the free cooling operation is performed when the temperature is equal to or lower than the comparison temperature and the outside air temperature is equal to or lower than the set temperature. Instead of a heat load device using cold water, a first to nth refrigerator that individually cools the cold water flowing out of the heat load device, and at least a first refrigerator of the first to nth refrigerators. Cooling the cooling water supplied to at least one of the first to n-th refrigerators and the heat exchanger via a predetermined switching mechanism. First to m-th cooling towers, and when the state of the outside air is a predetermined condition, the operation of the first to n-th refrigerators is stopped and the cooling water supplied to the heat exchanger is In the heat source system for performing a free cooling operation for cooling the cold water flowing out from the heat load device using the heat exchanger while cooling by a cooling tower,
At least the first refrigerator of the first to nth refrigerators and the heat exchanger are arranged in series with respect to the heat load device, and in the heat source system, immediately before flowing into the heat exchanger. A comparison temperature, which is a temperature obtained by subtracting a preset temperature from the cold water temperature of the cold water, is compared with the outside air temperature, and when the outside air temperature exceeds the comparison temperature, the cooling water supplied to the refrigerator is Normal operation of cooling the cold water flowing out from the heat load device using at least one of the first to n-th refrigerators without using the heat exchanger while cooling by the cooling tower. When the outside air temperature is equal to or lower than the comparison temperature and is an intermediate period excluding summer and winter, the operation of at least the first refrigerator among the first to nth refrigerators is stopped and stopped. The remaining freezer except for the freezer While cooling the cooling water supplied to at least one of them and the heat exchanger by the cooling tower, precooling the cold water flowing out from the heat load device using the heat exchanger and stopping the refrigeration A pre-cooling operation is performed to cool the cold water flowing out from the heat load device using at least one of the remaining refrigerators excluding the cooler, and the outside air temperature is equal to or lower than the comparison temperature in the winter season. If there is, a heat source system that performs the free cooling operation.   The heat source system includes a control device that performs any one of the normal operation, the precooling operation, and the free cooling operation, and the control device includes an outside air temperature measurement unit that measures an outside air temperature, and the heat exchanger. Cold water temperature measuring means for measuring the cold water temperature of the cold water immediately before flowing in, and temperature comparison means for comparing the measured outside air temperature with the comparison temperature, and the control device is configured to compare the outside air temperature with the comparison. When the temperature exceeds, the normal operation is performed, and when the outside air temperature is equal to or lower than the comparison temperature and is an intermediate period excluding summer and winter, the precooling operation is performed, and the outside air temperature is The heat source system according to claim 3, wherein the free cooling operation is performed when the temperature is equal to or lower than the comparison temperature and the winter season.   In the normal operation, the operating number of the first to n-th refrigerators and the operating number of the first to m-th cooling towers are determined according to the required load amount of the heat load device, and the pre-cooling operation is stopped. The heat source system according to any one of claims 1 to 4, wherein the number of operating remaining refrigerators and the number of operating cooling towers excluding the refrigerating units are determined according to a required load amount of the heat load device. The heat source system according to any one of claims 1 to 5, wherein the set temperature is 2 to 3 ° C.

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