JP3652974B2 - Primary pump heat source variable flow rate system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a primary pump heat source variable flow system that variably controls a heat medium flow rate according to a change in an air conditioning load state of a building and performs heat source control that is economical and has a high energy saving effect.
[0002]
[Prior art]
As energy-saving heat source systems, primary / secondary pump heat source variable flow systems that reduce the transport power of the primary pump and the secondary pump by supplying a heat medium according to the air conditioning load have already been realized. In the primary / secondary pump heat source variable flow rate system, both the primary and secondary pumps are operated with variable output.
[0003]
On the other hand, in a heat source system in which the heat transfer device has only a primary side pump, that is, a so-called primary pump type heat source system, the primary side pump is generally operated at a rated output regardless of the amount of air conditioning load. Only an amount of the heat medium capable of maintaining the water supply pressure is supplied to the load side, and the surplus heat medium is returned to the heat source machine via the bypass pipe without exchanging heat with the load side.
[0004]
[Problems to be solved by the invention]
In the conventional primary pump heat source variable flow rate system, the primary pump is operated at the rated output regardless of the air conditioning load, so when the air conditioning load becomes a partial load, the waste heat that inevitably passes through the bypass pipe is inevitably used. Media conveyance will occur. Actually, the air conditioning load of buildings such as office buildings is almost always a partial load throughout the year, and it is not preferable to always operate at the rated output from the viewpoint of economy and energy saving. In addition, the number control, that is, the heat source as a method for quickly performing the control operation at the time of start-up or the recovery control operation when the water supply temperature does not satisfy the condition (when the cold water supply temperature is excessive or the hot water supply temperature is excessively low). There is a method to quickly control to a predetermined temperature condition by increasing / decreasing the number of operating machines, but since it becomes stepwise variable flow rate control for each heat source machine, it becomes possible to satisfy the temperature condition of the heat medium However, regarding the flow conditions of the heat field, there is a risk of falling into an excessive flow rate or an excessive flow rate, and there is a problem that controllability and energy saving performance are impaired.
[0005]
The present invention has been made in view of the above circumstances, and a primary pump type heat source variable flow rate system that variably controls the heat medium flow rate according to fluctuations in the air conditioning load state of the building and performs heat source control with high economic and energy saving effect. The purpose is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a primary-pump heat source variable flow rate system that circulates and supplies cold / hot water only from the heat source side to air-condition the building, the load side device that processes the air conditioning load, and the load Heat source side device and cold / hot water transfer device for supplying cold / hot water to side device, cooling tower and cooling water transfer device for supplying cooling water to the heat source side device, cold / hot water supply side pipe and cold / hot water return water side tube A bypass pipe that connects the passages, and a variable flow rate control device that performs variable control so that cold and hot water and cooling water are circulated and supplied according to the air conditioning load. The variable flow rate control device determines a load state on the load side. Based on the determination result of the load state determination means, the cold / hot water conveyance amount detection means for detecting the cold / hot water conveyance amount by the cold / hot water conveyance device, and the cold / warm water supply temperature within a predetermined range. Cold and hot water transport The control output of the chilled / hot water transfer device or the opening degree of the bypass valve is calculated and output so that the chilled / hot water transfer amount by the device exceeds a predetermined value, and the load state determination means when the chilled / hot water supply temperature deviates from the predetermined range it is characterized in that it comprises means for outputting calculates the control output of the hot and cold water conveying device so as to increase the high-load control or low load hot and cold water conveyance amount without control based on the determination result of .
[0009]
The present invention, the Te primary pump type heat source variable flow system odor, before Symbol hot and cold water conveyance amount detecting means, cold by the cold and hot water conveying device based on the sum or the heat source-side flow rate of the bypass pipe flow and the load side flow It is characterized by detecting whether or not the water conveyance amount is a predetermined value or more.
[0010]
Or also the present invention, the Te primary pump type heat source variable flow system odor, before Symbol hot and cold water conveyance amount detecting means, hot and cold water conveyance amount by the cold and hot water conveying device based on the repatriation water tube differential pressure is the predetermined value or more It is characterized by detecting whether or not.
[0012]
Further, the present invention is characterized in that, in the primary pump heat source variable flow rate system, the control output of the cooling water transfer device is calculated based on the control output of the cold / hot water transfer device.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0014]
FIG. 1 is a configuration explanatory diagram showing a primary pump type heat source variable flow system according to an embodiment of the present invention.
[0015]
In FIG. 1, 11 is a cold / hot water generator, 12 is a cold / hot water primary pump, 13 is a cooling tower, 14 is a cooling water pump, and 15 is an air conditioner. A plurality of cold / hot water generators 11 are provided in parallel, and a cold / hot water primary pump 12, a cooling tower 13, and a cooling water pump 14 are provided corresponding to each. 16 is a forward header for mixing cold water or hot water from the cold / hot water generator 11, and 17 is a return header for mixing cold water or hot water returning to the cold / hot water generator 11. The bypass pipe 18 is provided so as to connect the forward header 16 and the return water pipe 19 or the forward header 16 and the return header 17, and a bypass valve 20 that adjusts the bypass pipe flow rate is provided on the bypass pipe line. The piping system is divided into a heat source side where a heat source device such as the cold / hot water generator 11 is arranged and a load side where a load device such as an air conditioner 15 is arranged with the bypass pipe 18 as a boundary. Reference numeral 21 denotes a pump variable flow rate control device (INV), which is provided corresponding to the cold / hot water primary pump 12 and the cooling water pump 14. 22 is a water temperature sensor for measuring the temperature of water supplied to the air conditioner 15, 23 is a water pressure gauge for measuring the load-side water pressure, 24 and 25 are flow meters for measuring the load flow and the bypass pipe flow, and 26 is a water pipe. It is.
[0016]
In the primary pump heat source variable flow rate system, the control operation differs depending on whether the air conditioning load is high or low.
[0017]
When the air conditioning load is in a high load state, the bypass valve 20 is controlled to be fully closed, and the amount of cold water or hot water supplied to the air conditioner 15 is variable by changing only the output of the cold / hot water primary pump 12. Be controlled. That is, cold water or hot water produced by the cold / hot water generator 11 is pumped by the cold / hot water primary pump 12 to the air conditioner 15 via the forward header 16 and the water supply pipe 26, and exchanges heat with the carrier air in the air conditioner 15. Then, it is returned again to the cold / hot water generator 11 via the return header 17 and the return water pipe 19. The air conditioning load thus transported to the cold / hot water generator 11 is discharged to the outside through the cooling water pump 14 and the cooling tower 13 of the cooling water circuit during cooling.
[0018]
On the other hand, when the air conditioning load is in a low load state, the cold / hot water primary pump 12 has a predetermined minimum control output, for example, a rating so that the cold / hot water generator 11 does not stop abnormally due to insufficient flow of the cold / hot water. The amount of cold water or hot water supplied to the air conditioner 15 is variably controlled by changing only the opening degree of the bypass valve 20. That is, the cold water or hot water produced by the cold / hot water generator 11 is pumped to the air conditioner 15 via the forward header 16 and the water supply pipe 26 by the cold / hot water primary pump 12, and at the same time, excess cold water or hot water is supplied to the bypass pipe 18. Sent to. The cold water or hot water sent to the air conditioner 15 exchanges heat with the carrier air in the air conditioner 15, and then returns to the cold / hot water generator 11 again via the return header 17 and the return water pipe 19, to the bypass pipe 18. The sent cold water or hot water is returned to the cold / hot water generator 11 again via the return header 17 and the return water pipe 19 without exchanging heat with the load side. The air conditioning load thus transported to the cold / hot water generator 11 is discharged to the outside through the cooling water pump 14 and the cooling tower 13 of the cooling water circuit during cooling.
[0019]
Reference numeral 27 denotes a heat source control device that performs optimal control of the cold / hot water primary pump 12, the cooling water pump 14, and the bypass valve 20 in accordance with fluctuations in the load state of the air conditioner 15. The heat source controller 27 includes a state input unit 28 that monitors the current operating state and load state and captures the data as data, and a load state that determines whether the load state of the air conditioner 15 is a high load state or a low load state A determination unit 29, a high load control calculation unit 30 for calculating control signals of the cold / hot water primary pump 12, the cooling water pump 14, and the bypass valve 20 at the time of high load, and a cold / hot water primary pump 12 and a cooling water pump at the time of low load 14 and the bypass valve 20 control signal calculation unit 31 and the water supply temperature compensation for calculating the control signal of the chilled water primary pump 12 and the cooling water pump 14 when the load side water supply temperature deviates from the set range. The control calculation part 32 and the control output part 33 which outputs the control signal with respect to the cold / hot water primary pump 12, the cooling water pump 14, and the bypass valve 20 are mounted. The state input unit 28 is provided with a processing unit that detects the amount of chilled / hot water transported by the chilled / hot water primary pump 12. In this embodiment, the total value of the bypass pipe flow rate and the load flow rate is detected as the amount of chilled / hot water transported. .
[0020]
The variable flow rate control in the heat source control device 27 of the primary pump type heat source variable flow rate system is performed as shown in the flowchart of FIG. That is, in the state input unit 28, signals relating to the operation state of each device and the load state such as temperature and flow rate are periodically input and data converted, and stored at a predetermined address in the memory. Subsequently, the load state determination unit 29 compares, for example, the load-side flow rate acquired through the state input unit 28 with a predetermined determination reference value to determine whether the load-side load state is high load or low load. Determined. Note that the predetermined determination reference value, as shown in FIG. 3 (a), using a value obtained by multiplying the coefficients a to the rated time of the water supply amount Q _MAX of cold and hot water generator 11 during operation. In the present embodiment example, the coefficient a is 0.5.
[0021]
When the load flow rate is equal to or greater than the predetermined determination reference value aQ _MAX , it is considered that the air conditioning load is in a high load state, and the high load control calculation unit 30 performs PID control with the water supply pressure set value as a target value (the water supply pressure is a target value). The optimum control output of the chilled / hot water primary pump 12 is calculated by calculating the pump control output to be a value. The control output of the cooling water pump 14 can be easily calculated by defining in advance as a primary expression related to the control output of the cold / hot water primary pump 12 with reference to the design data. In the high load state, the bypass valve 20 is fully closed (when the bypass valve 20 is not fully closed, it is gradually controlled to be fully closed). Here, the water supply pressure set value may be constant regardless of the load-side flow rate (constant water supply pressure control method). For example, as shown in FIG. 3B, the pump characteristic curve and the pipe resistance curve of the target heat source system. If the relational expression between the load-side flow rate and the water supply pressure set value is defined in advance based on the above, and the obtained load-side flow rate can be easily obtained by substituting this relational expression (flow cascade pressure control method) good.
[0022]
On the other hand, when the load flow rate is lower than the predetermined determination reference value aQ _MAX , the air-conditioning load is considered to be in a low load state, and the low load control calculation unit 31 performs the cold / hot water conveyance amount (bypass pipe flow rate and The optimum bypass valve opening is calculated by PID control so that the total value of the load flow rate becomes the flow rate set value (target value) (bypass valve control). In the low load state, the cold / hot water primary pump control output is fixed to a predetermined minimum control output (if the pump is not the minimum control output, it is gradually controlled to the minimum control output). This is to prevent the cold / hot water flow rate from being insufficient and the cold / hot water generator 11 from being abnormally stopped when the cold / hot water primary pump control output is lowered indefinitely according to the load state. The bypass valve 20 is operated for the purpose of bypassing excess cold / hot water that is not required on the load side.
[0023]
The latest control output controlled by the high load control calculation unit 30 or the low load control calculation unit 31 is output to the control output unit 33 via the water supply temperature compensation control calculation unit 32 described later, and the cold / hot water primary pump 12 and the cooling water An optimal control signal for the pump 14 and the bypass valve 20 is output to each device (a pump control signal / bypass valve opening signal is output from the control output unit 33). In order to consider the state transition between the high load state and the low load state due to the load fluctuation, when the load side is in the high load state, the control operation for completely closing the bypass valve 20 is performed. When in a load state, an operation for setting the cold / hot water primary pump control output to a predetermined minimum control output is performed as necessary.
[0024]
By the way, in order to maintain the thermal environment of the building satisfactorily while considering energy saving, it is necessary to pay attention to the controllability of the cold / hot water supply temperature as well as the optimal control of the cold / hot water flow rate.
[0025]
FIG. 4 is an operation explanatory view showing water supply temperature compensation control in the water supply temperature compensation control calculation unit 32 of the primary pump type heat source variable flow system. That is, in the case of the water supply temperature compensation control for chilled water, the compensation operation starts when the acquired water supply temperature exceeds the compensation start temperature (T _{CS · MAX} ), and the control output of the chilled / hot water primary pump (cold water pump) 12 is It gradually increases from the current output to the maximum control output. Here, the maximum control output is normally set to 100%. At this time, normal control at high load or normal control at low load, that is, PID control with the water supply pressure set value as the target value or bypass valve control with the flow rate set value as the target value is not performed. After that, when the water supply temperature decreases due to the effect of the compensation control and falls below the compensation end temperature, the compensation operation is finished, and the control output of the cold / hot water primary pump (chilled water pump) 12 is optimal from the maximum control output according to the current load state. Decrease gradually toward a more stable output. Conversely, in the case of hot water temperature compensation control for hot water, the compensation operation starts when the acquired water supply temperature falls below the compensation start temperature ( _{THS / MIN} ), and the control output of the cold / hot water primary pump (hot water pump) 12 Gradually increases from the current output to the maximum control output. After that, when the water supply temperature rises due to the effect of the compensation control and exceeds the compensation end temperature, the compensation operation is finished, and the control output of the cold / hot water primary pump (hot water pump) 12 is optimal from the maximum control output according to the current load state. Decrease gradually toward a more stable output.
[0026]
Next, FIG. 5 is a configuration explanatory view showing a primary pump type heat source variable flow system according to another embodiment of the present invention.
[0027]
In FIG. 5, 11 is a cold / hot water generator, 12 is a cold / hot water primary pump, 13 is a cooling tower, 14 is a cooling water pump, and 15 is an air conditioner. A plurality of cold / hot water generators 11 are provided in parallel, and a cold / hot water primary pump 12, a cooling tower 13, and a cooling water pump 14 are provided corresponding to each. 16 is a forward header that mixes cold water or hot water from the cold / hot water generator 11, and 17 is a return header 17 that mixes cold water or hot water returning to the cold / hot water generator 11. The bypass pipe 18 is provided so as to connect the forward header 16 and the return water pipe 19 or the forward header 16 and the return header 17, and a bypass valve 20 that adjusts the bypass pipe flow rate is provided on the bypass pipe line. The piping system is divided into a heat source side where a heat source device such as the cold / hot water generator 11 is arranged and a load side where a load device such as an air conditioner 15 is arranged with the bypass pipe 18 as a boundary. Reference numeral 21 denotes a pump variable flow rate control device, which is provided corresponding to the cold / hot water primary pump 12 and the cooling water pump 14. 22 is a water supply temperature sensor for measuring the water supply temperature to the air conditioner 15, 41 is a real terminal pressure gauge for measuring the load-side terminal water supply pressure, 42 is a differential pressure gauge for measuring the return water pipe differential pressure, and 24 is for measuring the load flow rate. It is a flow meter. Reference numeral 27 denotes a heat source control device that performs optimal control of the cold / hot water primary pump 12, the cooling water pump 14, and the bypass valve 20 in accordance with a change in the load state of the air conditioner 15. The heat source controller 27 includes a state input unit 28 that monitors the current operating state and load state and captures the data as data, and a load state that determines whether the load state of the air conditioner 15 is a high load state or a low load state A determination unit 29, a high load control calculation unit 30 for calculating control signals of the cold / hot water primary pump 12, the cooling water pump 14, and the bypass valve 20 at the time of high load, and a cold / hot water primary pump 12 and a cooling water pump at the time of low load 14 and the bypass valve 20 control signal calculation unit 31 and the water supply temperature compensation for calculating the control signal of the chilled water primary pump 12 and the cooling water pump 14 when the load side water supply temperature deviates from the set range. The control calculation part 32 and the control output part 33 which outputs the control signal with respect to the cold / hot water primary pump 12, the cooling water pump 14, and the bypass valve 20 are mounted. The state input unit 28 is provided with a processing unit that detects the amount of chilled / hot water transported by the chilled / hot water primary pump 12. In this embodiment, the flow rate (at low load) or load obtained from the measured value of the return water pipe differential pressure The flow rate (at high load) is detected as the cold / hot water conveyance amount.
[0028]
The variable flow rate control in the heat source control device 27 of the primary pump type heat source variable flow rate system of FIG. 5 is performed as shown in the flowchart of FIG. That is, in the state input unit 28, signals relating to the operation state of each device and the load state such as temperature and flow rate are periodically input and data converted, and stored at a predetermined address in the memory. Subsequently, the load state determination unit 29 compares, for example, the load-side flow rate acquired through the state input unit 28 with a predetermined determination reference value to determine whether the load-side load state is high load or low load. Determined. As described above, a value obtained by multiplying the rated water supply amount Q _MAX of the operating cold / hot water generator 11 by the coefficient a is used as the predetermined determination reference value. In the present embodiment example, the coefficient a is 0.5.
[0029]
When the load flow rate is equal to or greater than a predetermined determination reference value aQ _MAX , it is considered that the air conditioning load is in a high load state, and the high load control calculation unit 30 performs PID control (actual terminal) with the actual terminal water supply pressure setting value as a target value. The optimal control output of the cold / hot water primary pump 12 is calculated by calculating the pump control output so that the pressure becomes the target value. The control output of the cooling water pump 14 can be easily calculated by defining in advance as a primary expression related to the control output of the cold / hot water primary pump 12 with reference to the design data. In the high load state, the bypass valve 20 is fully closed (when the bypass valve 20 is not fully closed, it is gradually controlled to be fully closed).
[0030]
On the other hand, when the load flow rate is lower than the predetermined determination reference value aQ _MAX , it is considered that the air conditioning load is in a low load state, and in the low load control calculation unit 31, the return water pipe differential pressure becomes the differential pressure set value (target value). Thus, the optimum bypass valve opening is calculated by PID control. In the low load state, the cold / hot water primary pump control output is fixed to a predetermined minimum control output (if the pump is not the minimum control output, it is gradually controlled to the minimum control output). This is to prevent the cold / hot water flow rate from being insufficient and the cold / hot water generator 11 from being abnormally stopped when the cold / hot water primary pump control output is lowered indefinitely according to the load state. The bypass valve 20 is operated for the purpose of bypassing excess cold / hot water that is not required on the load side.
[0031]
The latest control data calculated by the high load control calculation unit 30 or the low load control calculation unit 31 is output to the control output unit 33 via the water supply temperature compensation control calculation unit 32, and the cold / hot water primary pump 12 and the cooling water pump 14 are output. In addition, an appropriate control signal for the bypass valve 20 is output to each device (pump control signal / bypass valve opening signal is output from the control output unit 33). In order to consider the state transition between the high load state and the low load state due to the load fluctuation, when the load side is in the high load state, the control operation for completely closing the bypass valve 20 is performed. When in a load state, an operation for setting the cold / hot water primary pump control output to a predetermined minimum control output is performed as necessary.
[0032]
In the above-described embodiment, the level of the air conditioning load state is determined based on the load flow rate, but the level of the air conditioning load state is determined using the return water pipe differential pressure instead of the load flow rate. Alternatively, the cold / hot water conveyance amount may be detected using the measurement value of the heat source side flow meter or the return water pipe differential pressure gauge. FIG. 7 shows a configuration of a primary pump heat source variable flow rate system according to another embodiment of the present invention.
[0033]
In FIG. 7, 11 is a cold / hot water generator, 12 is a cold / hot water primary pump, 13 is a cooling tower, 14 is a cooling water pump, 15 is an air conditioner, 16 is a forward header, and 17 is a return header. The bypass pipe 18 is provided so as to connect the forward header 16 and the return header 17, and a bypass valve 20 that adjusts the flow rate of the bypass pipe is provided on the bypass pipe line. The piping system is divided into a heat source side where a heat source device such as the cold / hot water generator 11 is arranged and a load side where a load device such as an air conditioner 15 is arranged with the bypass pipe 18 as a boundary. Reference numeral 21 denotes a pump variable flow rate control device (INV), which is provided corresponding to the cold / hot water primary pump 12 and the cooling water pump 14. Reference numeral 22 denotes a water supply temperature sensor for measuring the water supply temperature to the air conditioner 15, reference numeral 42 denotes a return water pipe differential pressure meter for measuring the differential pressure between the forward header 16 and the return header 17, and reference numeral 35 denotes a heat source side flow meter for measuring the heat source side flow rate. .
[0034]
The configuration of the processing unit mounted on the heat source control device 27 is the same as the configuration of FIGS. 1 and 5. The state input unit 28 is provided with a processing unit that detects the amount of chilled / hot water transported by the chilled / hot water primary pump 12. In this embodiment, the heat source side flow rate or the return water pipe differential pressure measured by the flow meter 35 is provided. The flow rate obtained from the measured value is detected as the cold / hot water conveyance amount.
[0035]
The variable flow rate control in the heat source control device 27 of the primary pump type heat source variable flow rate system is performed as shown in the flowchart of FIG. That is, in the state input unit 28, signals relating to the operation state of each device and the load state such as temperature and flow rate are periodically input and data converted, and stored at a predetermined address in the memory. Subsequently, the load state determination unit 29 compares the return water pipe differential pressure acquired through the state input unit 28 with a predetermined determination reference value to determine whether the load state on the load side is high load or low load. Determined.
[0036]
Regarded repatriation water tube differential pressure between the air conditioning load if a predetermined criteria value hereinafter continuously for a predetermined time period is in a low load state (no), in the low load control calculation unit 31, the hot and cold water primary pump 12 cold The optimal bypass valve opening is controlled by PID control so that the water conveyance amount (heat source side flow rate) becomes the flow rate setting value (target value) or the return water pipe differential pressure becomes the differential pressure setting value (target value). Calculated. (When the latter control method is adopted, the judgment reference value is set to be larger than the differential pressure set value.) In the low load state, the cold / hot water primary pump control output is set to a predetermined minimum control output. (When the pump is not at the minimum control output, gradually control to the minimum control output). This is to prevent the cold / hot water flow rate from being insufficient and the cold / hot water generator 11 from being abnormally stopped when the cold / hot water primary pump control output is lowered indefinitely according to the load state. The bypass valve 20 is operated for the purpose of bypassing excess cold / hot water that is not required on the load side. The control output of the cooling water pump 14 can be easily calculated by defining in advance as a primary expression related to the control output of the cold / hot water primary pump 12 with reference to the design data.
[0037]
On the other hand, regarded as air conditioning load if the repatriation water tube differential pressure rises above a predetermined determination reference value continuously for a predetermined time in a high load state (yes), the high-load control calculation unit 30, repatriation water pipe difference pressure value The optimum control output of the chilled / hot water primary pump 12 is calculated by PID control (calculating the pump control output so that the return water pipe differential pressure becomes the target value). In the high load state, the bypass valve 20 is fully closed (when the bypass valve 20 is not fully closed, it is gradually closed).
[0038]
The latest control data calculated by the high load control calculation unit 30 or the low load control calculation unit 31 is output to the control output unit 33 via the water supply temperature compensation control calculation unit 32, and the cold / hot water primary pump 12 and the cooling water pump 14 are output. In addition, an appropriate control signal for the bypass valve 20 is output to each device (pump control signal / bypass valve opening signal is output from the control output unit 33). In order to consider the state transition between the high load state and the low load state due to the load fluctuation, when the load side is in the high load state, the control operation for completely closing the bypass valve 20 is performed. When in a load state, an operation for setting the cold / hot water primary pump control output to a predetermined minimum control output is performed as necessary.
[0039]
【The invention's effect】
As described above, according to the present invention, the flow rate of the heat medium is variably controlled according to the fluctuation of the air conditioning load state of the building, the heat source is controlled economically and has a high energy saving effect, and the heat medium temperature condition is not disturbed. Thus, it is possible to provide a primary pump type heat source variable flow rate system that performs heat source control with excellent responsiveness and satisfies both the temperature condition and flow rate condition of the heat medium.
[Brief description of the drawings]
FIG. 1 is a configuration explanatory view showing a primary pump heat source variable flow system according to an embodiment of the present invention.
2 is a flowchart for explaining a variable flow rate control operation of the primary pump type heat source variable flow rate system of FIG. 1; FIG.
FIG. 3 is a diagram illustrating high load control and low load control of the primary pump heat source variable flow rate system of FIG. 1;
4 is a diagram for explaining a water supply temperature compensation control operation of the primary pump type heat source variable flow rate system in FIG. 1; FIG.
FIG. 5 is a configuration explanatory diagram showing a primary pump heat source variable flow rate system according to another embodiment of the present invention.
6 is a flowchart for explaining a variable flow rate control operation of the primary pump type heat source variable flow rate system of FIG. 5;
FIG. 7 is a configuration explanatory view showing a primary pump type heat source variable flow rate system according to another embodiment of the present invention.
8 is a flow chart for explaining a variable flow rate control operation of the primary pump type heat source variable flow rate system of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Cold / hot water generator 12 Cold / hot water primary pump 13 Cooling tower 14 Cooling water pump 15 Air conditioner 16 Out header 17 Return header 18 Bypass pipe 19 Return water pipe 20 Bypass valve 21 Pump variable flow control device (INV)
22 Water supply temperature sensor 23 Water supply pressure gauge 24 Load flow rate 25 Flow meter 26 Water supply pipe

Claims (4)

A primary-pump heat source variable flow system that circulates and supplies cold / hot water only from the heat source side to air-condition the building, and includes a load-side device that processes an air-conditioning load, and a heat source-side device that supplies cold / hot water to the load-side device A cooling tower for supplying cooling water to the heat source side device and a cooling water transfer device, a bypass pipe connecting the cold / hot water supply side pipe and the cold / hot water return water side pipe, A variable flow rate control device that performs variable control so as to circulate and supply cooling water according to an air conditioning load, the variable flow rate control device including a load state determination unit that determines a load state on a load side, and the cold / hot water conveyance A cold / hot water conveyance amount detecting means for detecting a cold / hot water conveyance amount by the apparatus, and a cold / hot water conveyance amount by the cold / hot water conveyance device is predetermined based on a determination result of the load state determination means when the cold / hot water supply temperature is within a predetermined range. Less than The control output of the chilled / hot water transfer device or the opening degree of the bypass valve is calculated and output so that when the chilled / warm water supply temperature deviates from the predetermined range, primary pump type heat source variable flow system characterized in that it comprises means for outputting operation control outputs of the hot and cold water conveying device so as to increase the low load-time cold and hot water conveyance amount without control.   The cold / hot water conveyance amount detection means detects whether or not the cold / hot water conveyance amount by the cold / hot water conveyance device is greater than or equal to a predetermined value based on the total value of the bypass pipe flow rate and the load side flow rate or the heat source side flow rate. The primary pump heat source variable flow rate system according to claim 1, wherein   2. The primary according to claim 1, wherein the cold / hot water conveyance amount detecting means detects whether or not the cold / hot water conveyance amount by the cold / hot water conveyance device is a predetermined value or more based on a return water pipe differential pressure. Pump type heat source variable flow system. The control output of the coolant transport device includes a primary pump type heat source variable flow system according to any one of claims 1 to 3, characterized in that it is calculated on the basis of the control output of the cold and hot water conveying device.

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