JP2016194386A - Heat source control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a secondary load state by processing "water amount" and "heat amount" different in physical unit as percentages being handled under the same index.SOLUTION: A total value of a load flow rate measurement value of a secondary-side cooling water system and an assumed value of a bypass flow rate, is divided by a total value of a designed flow rate of a heat source to calculate a cold water load flow rate ratio displayed by percentage, a load heat amount measurement value of the secondary-side cold water system is divided by a total value of a designed heat amount of the heat source to calculate a cold water load heat amount ratio displayed by percentage, a larger value of the cold water load flow rate ratio and the cold water load heat amount ratio is applied as a cold water load factor, and at least one of control of the number of heat sources and control of the flow rate of the heat source is implemented on the basis of the cold water load factor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat source control system that enables control of the number of heat sources and variable flow rate control of a cold / hot water pump in a heat source facility that uses a refrigerator or a cold / hot water generator that uses water or brine as a refrigerant as a heat source.

As a piping system for a heat source of an air conditioning facility, a sealed piping system in which cold water or hot water is circulated by a pump in a sealed pipe is known. In the sealed piping system, the heat source equipment is divided into a primary side and a secondary side by the header on the refrigerator side and the load side, and the primary pump depends on the presence or absence of the secondary pump responsible for the load side (secondary side) such as an air conditioner. There is a method and a secondary pump method. The primary pump system is a piping system that circulates all of the sealed piping from the heat source device to the air conditioner by using only the primary pump. In the secondary pump system, a primary pump and a secondary pump are provided, and the primary pump circulates cold water or hot water around the heat source equipment. And the sum of the water pressure loss of heat source equipment such as refrigerators, etc. The secondary pump is a chilled water coil or control valve that only circulates cold water or hot water to the secondary side such as an air conditioner. Responsible for water pressure loss. Unlike the primary pump system, the secondary pump system shares the head of the sealed piping system with two types of pumps.
In the following description, a case where cold water is used as a cooling medium and a heat source is used as a refrigerator will be described.
As shown in FIG. 8, the primary pump system includes a refrigerator (heat source unit) 101, a forward header 103, a return header 105, and an air conditioner (AHU) 107.
The refrigerator (heat source machine) 101 and the forward header 103 are connected by the primary side cold water forward pipeline 111, and the refrigerator (heat source machine) 101 and the return header 105 are connected by the cold water pump (primary pump). ) 115 is connected by the primary side cold water return pipe 113 to constitute the primary side of the heat source.

Also, the air conditioner (AHU) 107 and the forward header 103 are connected by a secondary chilled water outgoing passage 121, and the air conditioner (AHU) 107 and the return header 105 are connected by a secondary chilled water return water passage 119. Yes. Usually, a plurality of air conditioners (AHU) 107 are installed, and a two-way valve 109 is installed at the rear stage of each air conditioner (AHU) 107, and these constitute the secondary side of the heat source.
Further, an inter-header bypass passage 123 including an inter-header bypass valve 125 is provided between the forward header 103 and the return header 105 to perform header differential pressure control. The temperature control of the air conditioner can be stabilized by making the differential pressure applied to the load side constant while ensuring the minimum flow rate of the heat source refrigerator. Further, the return header 105 is provided with an expansion tank 127 to keep the inside of the sealed pipe at atmospheric pressure or higher to prevent pump suction side cavitation and absorb volume change due to the temperature of the cold water. The inter-header bypass valve 125 is controlled so that the differential pressure between the forward header 103 and the return header 105 is constant. By controlling the bypass valve 125, the primary flow rate ≧ secondary flow rate is compensated, and the high-temperature return cold water in the return header 105 does not flow back to the forward header 103 via the inter-header bypass path 123.

In order to absorb the volume fluctuation accompanying the water temperature change of the amount of water held in the sealed apparatus pipe, the closed pipe system is generally provided with an expansion tank 127 at a position above the uppermost part of the pipe as shown in FIG. Yes. The expansion tank includes an open expansion tank and a closed expansion tank.
As described above, the primary pump system is a piping system in which cold water is circulated from the refrigerator (heat source) 101 to the air conditioner (AHU) 107 only by the primary pump 115 as shown in FIG.
In the primary pump system, there is an amount of cold water flowing through the header bypass passage 123, the primary flow rate becomes larger than the secondary flow rate, and if the number of heat source operating units is controlled by the secondary side load heat amount, the temperature difference on the load side If not, the number of operating units will be insufficient, and the operating heat source unit will be overloaded. Therefore, in the primary pump system, the number of operating refrigerators (heat source units) 101 and the primary chilled water flow rate are determined by the secondary chilled water load flow rate.

On the other hand, as shown in FIG. 9, the secondary pump system includes a refrigerator (heat source unit) 101, a forward header 103, a return header 105, and an air conditioner (AHU) 107.
As shown in FIG. 9, the secondary pump system uses the primary pump 115 to circulate cold water around the refrigerator (heat source machine) 101, and 2 to circulate cold water to the load side such as the air conditioner 107. This is a piping system using the next pump 131.
Specifically, a second cold water forward header 129 is provided on the air header (AHU) 107 side of the forward header 103, and a plurality of cold water pumps (secondary) are provided between the forward header 103 and the second cold water forward header 129. The discharge pressure control valve 133 is provided in the pump 131 and the secondary pump inlet / outlet bypass pipe. Moreover, the bypass path 123 between headers is not provided with a bypass valve.
In the secondary pump system, the pressure from the second chilled water header 129 on the discharge side of the secondary pump 131 and the pressure signal from the pressure transmitter provided in the second chilled water header are calculated by the pressure indicating controller. To control the water supply pressure constant by controlling the rotation speed of the secondary pump, or to measure the secondary flow rate and calculate the required pressure from the measured load flow rate value, and to perform variable control of the water supply pressure as the estimated terminal pressure control Or the variable control of the water supply pressure is performed based on the differential pressure signal from the differential pressure transmitter installed at the end of the plurality of loads.

In the case of the secondary pump system, the primary flow rate and the secondary flow rate do not match, the flow rate suitable for the load is supplied by the variable flow rate control of the secondary pump, and the role of the heat source unit supplies the cold heat amount suitable for the secondary side heat amount Therefore, the number of heat source units is controlled by the secondary cold water load heat quantity.
In the case of the secondary pump method, the primary flow rate is not necessarily equal to or greater than the secondary flow rate, and therefore, different from the primary pump method. In the case of the secondary pump system, when the difference between the secondary chilled water going temperature and the secondary chilled water return temperature (hereinafter referred to as secondary chilled water ΔT) is smaller than the design value (ΔT = 5 ° C.), the secondary flow rate > The primary flow rate, and the high-temperature water in the return header 105 flows back to the forward header 103 via the inter-header bypass passage 123, and the secondary cold water forward temperature is, for example, from the chilled water outlet temperature of 7 ° C. In some cases, the temperature rises to 8 ° C or 9 ° C.

As described above, when the secondary chilled water temperature rises, the design of the chilled water coil as a heat exchanger is usually performed at the chiller outlet temperature as the chilled water supply temperature. The temperature difference with the target air temperature is reduced, and the cooling capacity of the air conditioner (AHU) 107 may be reduced.
If the location where the air conditioner (AHU) 107 is installed is an office, a complaint due to high temperature or high humidity may occur, and if the location where the air conditioner (AHU) 107 is installed is a factory, the quality of the product may be degraded. There is.
In order to solve such problems, conventionally, for temperature compensation of the secondary chilled water temperature, when the secondary water temperature becomes high, the standby heat source unit is turned on and the chilled water circulation amount on the primary side is reduced. Measures have been taken to add a function to prevent the reverse flow in the bypass between headers.

Japanese Patent No. 3306612 Japanese Patent No. 4351545

However, with such conventional measures, control logic (control method switching, control method transition conditions, etc.) becomes complicated, forced ON / OFF due to temperature becomes a disturbance, and secondary side chilled water ΔT varies. It has been pointed out that there are problems such as the secondary water supply temperature not stabilizing and the bypass flow rate between the return and return headers increasing the primary pump power consumption, which is undesirable from the viewpoint of energy saving and comfort. Yes.
Therefore, the primary pump system and the secondary pump system are configured so that the capacity of the chiller (heat source) 101 can be forcibly increased when the secondary chilled water feed temperature rises, assuming a decrease in the capacity of the chilled water heat source. (For example, refer to Patent Document 1).

However, in the secondary pump system, the secondary chilled water temperature difference <the design temperature difference, the secondary chilled water flow rate> the primary chilled water flow rate, and the secondary chilled water return temperature rises. A function for forcibly increasing the number of units or forcibly increasing the flow rate of primary cold water is required.
Further, it is necessary to switch the control method between the secondary pump method and the primary pump method.

  Further, in the cooling power supply system using a plurality of refrigerators and the number control device for the refrigerators used in the cooling power supply system, the cooling water flow rate to be passed through the cooling load, the inlet cooling water temperature and the outlet cooling water temperature of the cooling load. The number of refrigerators to be operated is determined based on a predetermined reference value from each of the load-side exchange heat calculated from the chilled water flow rate, and the larger number of these units is set as the actual operation number. Detecting whether the cooling water temperature is lower than the rated value at a predetermined timing, and when the cooling water temperature is lower than the rated value, the cooling water temperature is proportional to the deviation from the rated value to the lower side. It is disclosed that it is changed in the direction of increasing the number (for example, see Patent Document 2).

  However, in Patent Document 2, in order to determine the number of units to be operated based on a predetermined refrigeration load reference value from each of “load chilled water flow rate” and “chilled water load calorie”, whichever flow rate and calorie have different physical units? Since the larger number is set and controlled, it is troublesome to summarize the indicators.

  The present invention has been made to solve such a conventional problem, and its purpose is to treat secondary load by treating “water quantity” and “heat quantity” having different physical units as percentages that can be handled by the same index. The object is to provide a heat source control system capable of simplifying the state.

  An example of a heat source control system according to the present invention includes a heat source, a primary side provided with a primary cold water pump on the way, a first forward header connected to the cold water outlet side of the heat source via a primary cold water forward line. A return header connected to the chilled water inlet side of the heat source via a chilled water return pipe, a header bypass path connected between the first forward header and the return header, and 2 to the first forward header. A secondary forward chilled water return conduit and a secondary chilled water return conduit connected between the second forward header and the return header, comprising a second forward header connected via a secondary chilled water pump and an air conditioner And a control device connected to the heat source and the primary chilled water pump, and a discharge pressure control valve for controlling the discharge pressure of the secondary chilled water pump, the control device comprising the secondary chilled water outgoing pipe Load flow measurement of a load-side flow meter installed in either the road or the secondary chilled water return pipe And the estimated value of the flow rate flowing through the header bypass passage is divided by the total value of the design flow rate of the heat source to calculate a percentage chilled water load flow rate ratio, Load calorific value measurement value calculated by multiplying the difference between the measurement values of the load outlet temperature sensor and the load inlet temperature sensor respectively installed in the secondary side chilled water return pipe and the load flow rate measurement value of the load side flow meter, Calculate the chilled water load calorie ratio expressed as a percentage by dividing by the total value of the design heat quantity of the heat source, the larger one of the chilled water load flow rate ratio and the chilled water load calorie ratio as the chilled water load factor, and the chilled water load factor Based on the above, at least one of the number control of the heat sources and the flow control of the heat sources by the primary chilled water pump flow rate control is performed.

  Another example of the heat source control system according to the present invention includes a heat source, a forward header connected to a chilled water outlet side of the heat source via a primary chilled water forward line, and a primary chilled water pump provided in the middle. A return header connected to the cold water inlet side of the heat source via a cold water return pipe, a header bypass path connected between the forward header and the return header, an air conditioner, and the forward header; The secondary side cold water forward pipe and the secondary side cold water return pipe connected between the return header, the control device connected to the heat source and the primary cold water pump, the heat source, and the primary side The primary chilled water pump having a lift for the pressure loss of the chilled water outbound conduit, the primary side chilled water return conduit, the air conditioner, the secondary chilled water outbound conduit, and the secondary chilled water return conduit; The control device is installed in either the secondary chilled water outbound pipeline or the secondary chilled water return pipeline. Calculate the chilled water load flow rate ratio by dividing the total value of the load flow measurement value of the side flow meter and the estimated value of the flow rate flowing through the header bypass path by the total value of the design flow rate of the heat source, Calculated by multiplying the difference between the measured values of the load outlet temperature sensor and the load inlet temperature sensor installed in the secondary side chilled water outgoing line and the secondary side chilled water return line, respectively, and the load flow rate measured value of the load side flow meter The chilled water load calorie ratio is calculated by dividing the measured load calorific value by the total value of the design heat quantity of the heat source, and the larger one of the chilled water load flow rate ratio and the chilled water load calorie ratio is calculated. Based on the chilled water load factor, at least one of the heat source flow rate control and the primary chilled water pump flow rate control is performed based on the chilled water load factor.

  Still another example of the heat source control system according to the present invention includes a heat source, a first forward header connected to the warm water outlet side of the heat source via a primary-side warm water outbound conduit, and a primary warm water pump. A return header connected to the hot water inlet side of the heat source via a primary hot water return pipe, a header bypass path connected between the first forward header and the return header, and the first forward A secondary forward header connected to the header via a secondary warm water pump, an air conditioner, and a secondary warm water forward conduit and secondary warm water connected between the second forward header and the return header A return pipe, a control device connected to the heat source and the primary hot water pump, and a discharge pressure control valve for controlling the discharge pressure of the secondary hot water pump, the control device comprising the secondary side Load-side flow meter load installed in either the hot water outbound pipe or the secondary hot water return pipe The total value of the measured amount of flow and the estimated value of the flow rate flowing through the header bypass passage is divided by the total value of the design flow rate of the heat source to calculate the percentage of the hot water load flow rate, and the secondary side hot water flow rate is calculated. Load calorimetry calculated by multiplying the difference between the measured values of the load outlet temperature sensor and the load inlet temperature sensor respectively installed in the pipeline and the secondary hot water return pipeline and the load flow rate measurement value of the load side flow meter The value is divided by the total value of the design heat quantity of the heat source to calculate the hot water load heat quantity ratio expressed as a percentage, and the larger one of the hot water load flow rate ratio and the hot water load heat quantity ratio is set as the hot water load ratio, Based on the hot water load factor, at least one of the number control of the heat sources and the heat source flow rate control by the primary hot water pump flow rate control are performed.

  Still another example of the heat source control system according to the present invention is a primary that includes a heat source, a forward header connected to the hot water outlet side of the heat source via a primary-side hot water outgoing line, and a primary hot water pump. A return header connected to the hot water inlet side of the heat source via a side hot water return pipe, an inter-header bypass path connected between the forward header and the return header, and an air conditioner, the forward header And a secondary side hot water outgoing line and a secondary side hot water return line connected between the return header, a control device connected to the heat source and the primary hot water pump, the heat source, the primary A primary hot water pump having a head for a pressure loss of a side hot water outgoing pipe, the primary side hot water return pipe, the air conditioner, a secondary side hot water outgoing pipe, and a secondary side hot water return pipe; And the control device is installed in either the secondary-side hot water outbound conduit or the secondary-side warm water return conduit. Calculate the hot water load flow rate ratio by dividing the total value of the load flow rate measurement value of the load side flow meter and the estimated value of the flow rate flowing through the header bypass path by the total value of the design flow rate of the heat source. The difference between the measured values of the load outlet temperature sensor and the load inlet temperature sensor respectively installed in the secondary side hot water outgoing line and the secondary side hot water return line is multiplied by the load flow rate measured value of the load side flow meter. The hot water load calorie ratio is calculated by dividing the measured value of load calorie calculated by the total value of the design heat quantity of the heat source, and the larger one of the hot water load flow rate ratio and the hot water load calorie ratio is calculated. And at least one of the heat source flow rate control by the number control of the heat sources and the primary hot water pump flow rate control is performed based on the hot water load factor.

According to the present invention, the secondary load state can be simplified by setting different physical quantities of heat and flow to the same unit of percentage.
According to the present invention, by displaying the secondary load state as a percentage, it is possible to cope with either the primary pump system or the secondary pump system.
According to the present invention, it is possible to simultaneously realize the heat source number control and the primary chilled water variable flow rate control with one control parameter.

According to the present invention, there are few disturbances compared to a general control method, and energy saving and comfort are improved.
ADVANTAGE OF THE INVENTION According to this invention, it can also contribute to the reduction of primary pump power consumption by reducing the bypass flow volume between return headers.
According to the present invention, since the control logic is simple, the development cost and maintenance cost of the controller are low.

It is explanatory drawing which shows 1st Embodiment of this invention. It is a figure which shows the control flow of 1st Embodiment of this invention. It is a figure which shows the setting of the heat source number control by 1st Embodiment of this invention. It is a figure which shows the example of application of 1st Embodiment of this invention. It is a figure which shows the example of application of 1st Embodiment of this invention. It is a figure which shows the example of application of 1st Embodiment of this invention. It is explanatory drawing which shows 2nd Embodiment of this invention. It is a figure which shows the conventional primary pump system. It is a figure which shows the conventional secondary pump system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment of the present invention.
The present embodiment shows an example in which the heat source control system according to the present invention is applied to a secondary pump system.

The heat source control system includes four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator (heat source machine R4) 11d, forward header 27, return A header 29 and two air conditioners (AHU) 49a and 49b are provided.
The four refrigerators (heat source machine R1) 11a, the refrigerator (heat source machine R2) 11b, the refrigerator (heat source machine R3) 11c, and the refrigerator (heat source machine R4) 11d include a PLC (Programmable) that is a controller of the heat source control system. A heat source start / stop command and a chilled water outlet temperature SP (Set Point) are input from the Logic Controller. The four refrigerators (heat source machine R1) 11a, the refrigerator (heat source machine R2) 11b, the refrigerator (heat source machine R3) 11c, and the refrigerator (heat source machine R4) 11d have a heat source operation state, a heat source failure state, and The light load operation state is output to the PLC.

  Between the four refrigerators (heat source machine R1) 11a, the refrigerator (heat source machine R2) 11b, the refrigerator (heat source machine R3) 11c, the refrigerator (heat source machine R4) 11d and the forward header 27 are four primary. The side cold water outgoing pipes 13a, 13b, 13c, and 13d are connected to each other. Refrigerator outlet cold water temperature sensors 15a, 15b, 15c, and 15d are provided in the primary side cold water outgoing pipes 13a, 13b, 13c, and 13d. The temperature PV (Process Value: measured value) of the refrigerator outlet cold water temperature sensors 15a, 15b, 15c, and 15d is output to the PLC.

  Between the four refrigerators (heat source machine R1) 11a, the refrigerator (heat source machine R2) 11b, the refrigerator (heat source machine R3) 11c, the refrigerator (heat source machine R4) 11d and the return header 29 are four primary. The side cold water return pipes 17a, 17b, 17c, and 17d are connected to each other. The four primary chilled water return pipes 17a, 17b, 17c, and 17d are directed from the return header 29 to the four refrigerators (heat source machines) 11a, 11b, 11c, and 11d, and the heat source flow meters 19a, 19b, and 19c. , 19d, cold water pumps (primary pumps) 21a, 21b, 21c, 21d, and refrigerator inlet cold water temperature sensors 23a, 23b, 23c, 23d, respectively. The measured values of the refrigerator inlet cold water temperature sensor temperature sensors 23a, 23b, 23c, and 23d are output to the PLC.

The flow rate PV of the heat source device flow meters 19a, 19b, 19c, and 19d is output to a flow indication controller (FIC: Flow Indicating Controller) 25a, 25b, 25c, and 25d. The flow rate indicating controllers 25a, 25b, 25c, and 25d receive the flow rate SP from the PLC, and adjust the rotational speeds of the cold water pumps (primary pumps) 21a, 21b, 21c, and 21d so that the flow rate PV becomes the flow rate SP. INV is controlled and varied.
The forward header 27 and the return header 29 are connected via an inter-header bypass path 31.

  Thus, in this embodiment, four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator (heat source machine R4) 11d, The primary side of the heat source is constituted by the primary side cold water outgoing lines 13a, 13b, 13c, 13d, the forward header 27, the return header 29, and the four primary side cold water return pipes 17a, 17b, 17c, 17d. Has been.

On the other hand, the second forward header 83 is connected to the forward header 27 via a plurality of secondary chilled water pumps 85a and 85b and a part of the secondary chilled water outgoing passage. The secondary chilled water pumps 85 a and 85 b are connected in parallel between the forward header 27 and the second forward header 83. Further, a secondary pump inlet / outlet bypass pipe 87 provided with a discharge pressure control valve 89 is connected between the forward header 27 and the second forward header 83.
Between the second forward header 83 and the return header 29, a secondary chilled water outlet 39 connecting the second forward header 83 and the air conditioner (49a, 49b), and an air conditioner (49a, 49b). And a secondary side cold water return channel 41 for connecting the return header 29 to the return header 29. Although there are two systems in FIG. 1, there are actually a number of systems that constitute the secondary side of the heat source. The secondary side chilled water outgoing channel 39 branches into two lines, the first line chilled water pipe 43a and the second line chilled water pipe 43b, and the first line chilled water pipe 43a and the second line chilled water pipe 43b join the secondary side chilled water return channel 41. To do.

  The 1-system cold water pipe 43a and the 2-system cold water pipe 43b include load inlet temperature sensors 45a and 45b, two-way valves 47a and 47b, an air conditioner (AHU1) 49a, an air conditioner (AHU2) 49b, and a load outlet temperature sensor. 51a and 51b and load-side flow meters 53a and 53b are provided, respectively. The measured values of the load inlet temperature sensors 45a and 45b and the load outlet temperature sensors 51a and 51b are output to the PLC.

  A free cooling branch chilled water pipe 55 that is thermally connected to the free cooling cooling tower 59 via a free cooling heat exchanger 57 is connected to the secondary side cold water return water path 41 at two points, a branch point and a junction. Yes. The free cooling branch chilled water pipe 55 is connected to the free cooling flow meter 61, the free cooling chilled water pump 63, and the free cooling heat exchanger inlet temperature sensor from the branch point with the secondary side chilled water return channel 41 toward the free cooling heat exchanger 57. 65. The free cooling flow rate PV measured by the free cooling flow meter 61 is output to the flow control flow rate indicating controller (FIC) 67, and the free cooling flow rate PV is output from the flick flow rate indicating controller 67 to the PLC. Further, the free cooling flow rate SP is input from the PLC to the flicker flow rate indicating controller 67. The flick flow rate indicating controller 67 controls the number of rotations of the free cooling chilled water pump 63 by controlling the free cooling chilled water pump inverter INV so that the free cooling flow rate PV becomes the free cooling flow rate SP. A free cooling heat exchanger outlet temperature sensor 69 is provided in the free cooling branch chilled water pipeline 55 on the downstream side of the free cooling heat exchanger 57. The measured values of the free cooling heat exchanger inlet temperature sensor 65 and the free cooling heat exchanger outlet temperature sensor 69 are output to the PLC.

A free-cooling cooling tower outlet temperature sensor 73 and a free-cooling water pump 75 are provided in the free-fluid circulation water passage 71 that connects the free-cooling heat exchanger 57 and the free-cooling cooling tower 59. The flick cooling water pump 75 includes an inverter INV, and the rotation speed of the flick cooling water pump 75 controls the inverter INV by the output of the instruction controller 77 for temperature control based on the measurement value of the free cooling heat exchanger outlet temperature sensor 69. It is adjusted by doing.
The free cooling cooling tower 59 is cooled by a cooling tower fan 81 provided with an inverter INV. The number of revolutions of the cooling tower fan 81 is adjusted by controlling the inverter INV by the output of the temperature control instruction controller 79 based on the measured value of the free cooling cooling tower outlet temperature sensor 73.
In the present embodiment, the return water free cooling is configured by the freque circulation water channel 71 and the free cooling branch chilled water pipe 55 that are thermally connected via the free cooling heat exchanger 57.

  In this embodiment, the PLC calculates the total value of the load flow rate measurement value PV of the secondary side chilled water system constituted by the 1-system chilled water pipe 43a and the 2-system chilled water pipe 43b and the estimated value of the flow rate of the inter-header bypass path 31. Dividing by the total value of the design flow rate of four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator (heat source machine R4) 11d, and displaying percentage Calculate the cold water load flow rate ratio. In addition, the PLC calculates the load calorific value of the secondary chilled water system composed of the 1-system chilled water pipe 43a and the 2-system chilled water pipe 43b, the four refrigerators (heat source machine R1) 11a, and the refrigerator (heat source machine R2). 11b, the cold water load calorie | heat amount ratio which is divided by the total value of the design calorie | heat amount of the refrigerator (heat source machine R3) 11c, and the refrigerator (heat source machine R4) 11d is displayed as a percentage display. The PLC uses the larger value of the chilled water load flow rate ratio and the chilled water load heat rate ratio as the secondary chilled water load factor, and based on this secondary chilled water load factor, controls the number of heat sources or changes the primary chilled water flow rate. It is configured to perform control.

Next, a method for calculating the cold water load factor in this embodiment will be described based on the control flow of the cold water load factor shown in FIG.
1) The calculation of the cold water load flow rate ratio (steps S1 to S4) will be described.
First, as a cold water heat source, the PLC is a total heat source to be increased or decreased, that is, four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator. (Heat source machine R4) The total value of the design flow rate (m ³ / h) of 11d is obtained. Therefore, free cooling, hot water heat sources, and heat sources that are not subject to increase or decrease are excluded.
Maximum value of chilled water flow rate (m ³ / h) = total value of design flow rate of chilled water heat source (step S1)

Next, the PLC calculates the chilled water load flow rate by the following equation from the load flow rate measurement value (m ³ / h) and the chilled water bypass flow rate estimated value (m ³ / h).
In the following description, the load flow rate of the 1-system cold water pipe 43a will be described as 1-system load flow rate, and the load flow rate of the 2-system cold water pipe 43b will be described as 2-system load flow rate.
When the secondary chilled water pumps 85a and 85b are stopped, the two-system load flow rate PV = 0 (m ³ / h). When one of the secondary chilled water pumps 85a and 85b is operating, the PLC performs the following calculation.
Cold water load flow rate PV (m ³ / h) = 1 system load flow rate PV + 2 system load flow rate PV (step S2)

Next, the PLC obtains the chilled water required flow rate SP, which is the target value of the chilled water flow rate of the entire heat source, by taking the bypass flow rate assumed value into consideration, using the following equation.
Chilled water required flow rate SP (m ³ / h) = Chilled water load flow rate PV + Bypass flow rate assumption value (step S3)
Here, the bypass flow rate assumption value is a value of about 10% or less of the chilled water flow rate design value of the base heat source at, for example, 0 m ³ / h or more. When the bypass flow rate assumption value is zero, the energy saving performance is the best, but there is a risk that the secondary chilled water temperature will rise due to the backflow of the bypass pipe. Usually, the estimated bypass flow rate is about 10% of the design flow rate of one heat source unit.
Next, the PLC calculates the cold water load flow rate ratio (%) by the following equation.
Chilled water load flow rate ratio (%) = 100 × chilled water required flow rate SP ÷ chilled water flow rate maximum value (step S4)

2) The calculation of the cold water load heat ratio (steps S5 to S8) will be described.
First, as a cold water heat source, the PLC is a total heat source to be increased or decreased, that is, four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator. (Heat source machine R4) The total value of the design heat quantity (m ³ / h) of 11d is obtained.
Maximum value of chilled water heat amount = total value of design heat amount of chilled water heat source (step S5)
Next, the PLC has 1 system load flow PV (measured flow value of m ³ / h, 53a) ≧ 0 and 1 system cold water ΔT (° C., temperature difference between measured values of 51a and 47a) ≧ 0, One system load calorie | heat amount (kW) is calculated by following Formula.
In the following description, the load heat quantity of the 1-system cold water pipe 43a will be described as 1-system load heat quantity, and the load heat quantity of the 2-system cold water pipe 43b will be described as 2-system load heat quantity.

1 system load calorie (kW) = 1.163 × 1 system load flow PV × 1 system chilled water ΔT (temperature difference between 51a and 47a)
Here, 1.163 (kW) is obtained by the following equation.
1 (m ³ / h) × 1 (kcal / kg · ° C.) × 4.1868 (kJ / kcal) × 1000 (kg / m ³ ) ÷ 3600 (s / h) = 1.163 (kW)
Two-system load flow rate PV (measured flow rate value of m ³ / h, 53b) ≧ 0 and cold water ΔT (° C.) ≧ 0, and the two-system load heat amount (kW) is calculated by the following equation.

2 system load heat quantity (kW) = 1.163 × 2 system load flow PV × 2 system cold water ΔT (temperature difference between 51b and 47b)
Free cooling (also called flick) chilled water flow rate PV (m ³ / h, measured flow value of 61) ≧ 0 and chilled water ΔT (temperature difference between measured values of ° C., 65 and 69) ≧ 0, and flick chilled water heat quantity (KW) is calculated by the following equation.
When the operation state of the flicker chilled water pump = 0 (stopped), the amount of heat generated by the flicker chilled water PV = 0 (kW).
Heat quantity of chilled cold water (kW) = 1.163 x Flique chilled water flow rate PV x chilled water ΔT (temperature difference between 65 and 69)
The PLC calculates the cold water load calorie by the following equation. Note that the cold water required heat amount SP ≧ 0.
Cold water load heat PV (kW) = 1 system heat load PV + 2 system load heat PV (step S6)

Moreover, PLC calculates cold-water request | requirement calorie | heat amount with following Formula.
For example, in the embodiment, when pre-cooling by free cooling is performed, the heat amount by free cooling may be subtracted from the load heat amount.
Chilled water required heat amount SP (kW) = load heat amount PV-frik generation heat amount (step S7)
Here, the return water flick system is a pre-cooling heat source for the refrigerators (R1 to R4), and therefore can be used in principle if the outside air wet bulb temperature is lower than the cold water return water temperature even in the middle period. Yes, leading to a reduction in the operating power of the refrigerator due to the use of natural cold.
The total value of the design cold water heat quantity (kW) of the heat source (excluding flick) that can be operated as the cold water heat source is obtained.
Next, the PLC calculates the chilled water load heat quantity ratio = 100 × the chilled water required heat quantity SP / the chilled water heat quantity maximum value (step S8).
When the cold water load heat quantity PV = 0 (kW), the cold water load heat quantity ratio = 0 (%).

3) The calculation of the cold water load factor will be described.
In the present embodiment, the PLC sets a large value between the chilled water flow rate ratio and the chilled water load heat amount ratio as the chilled water load factor.
Chilled water load factor = MAX (Chilled water flow rate ratio, Chilled water load heat rate ratio) (Step S9)
“MAX (A)” indicates a function that returns the maximum value of A.
4) In the cold water load calculation method, the PLC determines whether to consider the amount of heat or only the flow rate (step S10).
When considering the amount of heat, the PLC processes as cold water load factor = MAX (chilled water flow rate ratio, cold water load heat amount ratio) (step S11).
When only the flow rate is considered as in the case of the primary chilled water flow rate ≧ secondary chilled water flow rate in the primary pump system, the PLC processes the chilled water load factor = the chilled water flow rate ratio (step S12).
And PLC performs heat source number control (increase / decrease stage control) based on the cold water load factor calculated | required by step S11 or step S12 (step S13).

Next, the physical meaning of the cold water load factor will be considered.
The aim of the cold water variable flow rate control by the optimum capacity method is to change the ratio of the amount of heat generated by each heat source, but the amount of heat cannot be directly controlled. Therefore, on the assumption that the secondary side cold water ΔT is the same, the ratio of the amount of heat generated by each heat source is indirectly changed by changing the flow rate of the cold water. Thus, since the physical quantity which PLC outputs is a flow volume, the load with respect to PLC is a cold water load flow volume.

Therefore, the chilled water load flow rate ratio is calculated by adding the bypass flow target value for securing a fixed return bypass flow rate to the chilled water load flow rate measurement value. The reason why the flow rate ratio (%) is used instead of the flow rate absolute value (m ³ / h) is to enable comparison between the amount of heat and the flow rate described later.
When the primary side variable flow rate control is performed at this chilled water load flow rate ratio, a shortage of the primary chilled water flow rate occurs when the secondary chilled water ΔT is larger than the design condition (usually 5 ° C.). As a countermeasure, the chilled water load calorific value is converted into the chilled water load flow rate (secondary chilled water ΔT = design condition) to obtain the chilled water load calorie ratio (value corresponding to the chilled water load flow rate ratio).

The magnitude of the chilled water load flow rate ratio and the chilled water load calorie ratio are compared, and the larger one is the chilled water load factor. If “secondary cold water ΔT = design ΔT” or “secondary cold water ΔT <design ΔT”, then “cold water load factor = cold water load flow rate ratio” and “secondary cold water ΔT> design ΔT”. Then, “Cooling water load factor = Cooling water load calorie ratio”. This cold water load factor is a control parameter of the PLC.
In summary, the chilled water load factor can be said to be a percentage display of the primary chilled water flow rate that the heat source needs to send to the secondary side in consideration of the size of the secondary chilled water ΔT and securing the return bypass flow rate. .

Next, heat source number control (increase / decrease stage number control) will be described.
The PLC uses the first priority (No. 1) refrigerator (heat source machine R1) 11a as a base source, and is always turned on when the start / stop command of the cold heat source group is turned on.
Based on FIG. 3, the heat source start / stop priority is set in advance for the step increase setting (Up1 to Up6) and the step decrease setting (Dn1 to Dn6).
For example, when the cold water load factor exceeds 36% when the first (No. 1) refrigerator (heat source device R1) 11a is operating, the second (No. 2) refrigerator (heat source device R2) 11b. If the chilled water load factor exceeds 54% when the second (No. 2) refrigerator (heat source machine R2) 11b is also operating, the third (No. 3) Or setting the number of stages (Up2) of the refrigerator (heat source machine R3) 11c.
On the other hand, if the cold water load factor falls below 49% while the third (No. 3) refrigerator (heat source device R3) 11c is operating, the third (No. 3) refrigerator (heat source device R3) ) 11c is stopped and stepped down (Dn2), and when the second (No. 2) refrigerator (heat source machine R1) 11b is operating and the chilled water load factor falls below 32%, the second (No. The refrigerator (heat source machine R1) 11b of 2) is stopped and stepped down (Dn1).
The PLC compares the chilled water load factor with the increase / decrease setting at a constant cycle (about 10 to 20 minutes), calculates the increase point (Up1, 2, 3, Dn1, 2, 3), and operates. The heat source machine (No. 1, 2, 3) is determined.
If necessary, rotate for the purpose of leveling the operating time.

When the number of operating heat sources changes, a certain waiting time is provided.
For a certain time after the heat source is stopped, the restart of the target heat source is prohibited by the PLC.
When the failure of the heat source is detected, the PLC transmits a stop command to the target heat source and excludes it from the number control target.
In order to correct the capacity fluctuation of the heat source machine, the PLC performs a step-up correction based on the going temperature. However, when there is a heat source in a light load operation state, the stage is not increased by the going temperature.
In order to correct the capacity variation of the heat source machine, the PLC performs a step reduction correction based on the temperature in the return header 29.
When the start / stop command for each heat source and the operation state of each heat source do not match, the PLC transmits a stop command to the target heat source.
When the heat source fails to start, the heat source in the next order is set as an alternative operation according to the load.

Next, based on FIGS. 4 to 6, a specific control method according to the size of the secondary side cold water ΔT will be described when the secondary load heat quantity is 60% and the design condition of the secondary load cold water ΔT is 10 ° C. To do.
The specifications of the heat sources (R-1, R-2) are the design value of the secondary side cold water ΔT = 10 ° C., the rated cold water heat quantity = 700 RT, and the design value of the cold water flow rate = 211.5 m ³ / h.

Under the condition of the design value of the secondary side cold water ΔT = 10 ° C., the secondary cold water calorific value is 1400 RT when 100% and 840 RT when 60%. The secondary chilled water flow rate is 423.0 m ³ / h when the secondary chilled water calorie is 100%, and 253.8 m ³ / h when the secondary chilled water calorie is 100%. Further, the assumed amount of bypass flow from the forward header to the return header is 10.0 m ³ / h.

２次側冷水ΔＴが１００％の場合には、２次側冷水ΔＴ＝１０．０℃（１００％）、１次側冷水ΔＴ＝１０．０℃（１００％）となる。また、２次流量比率は、２次側冷水ΔＴが１００％であるから、１００％×６０％＝６０％となり、２次熱量比率６０％と一致する。
図４の例での１次流量の算出方法は下記の通りである。
負荷流量比率は、（２５３．８＋１０）／４２３＝６２．４％である。
負荷比率は、負荷流量比率と負荷熱量比率のいずれか大きい方の値をとる。すなわち、
負荷比率＝ＭＡＸ（負荷流量比率，負荷熱量比率）
＝ＭＡＸ（６２．４％，６０％）＝６２．４％である。
また、１次流量は、負荷比率と設計流量との積で求めることができる。すなわち、
１次流量＝負荷比率×設計流量＝６２．４％×４２３＝３３２．３ｍ^３／ｈである。
また、図４の例でのバイパス流量は１０．０ｍ^３／ｈであり、想定値で見込んだバイパス流量に一致する。また、図４の例での２次冷水往温度は７℃であり、冷凍機の冷水出口温度と同じ温度となる。なお、バイパス流量の想定値を１０ｍ^３／ｈにすると、バイパス流量を０ｍ^３／ｈとする場合と比べて、冷水ポンプの消費エネルギーが多少増加するものが、２次冷水温度が安定するため空調機の運用における快適性は向上する。 First, the case where the secondary side cold water ΔT is 100% will be described with reference to FIG. The flow rates of the primary and secondary chilled water, the primary chilled water ΔT and the secondary chilled water ΔT, and the amount of heat in the example of FIG.

When the secondary side cold water ΔT is 100%, the secondary side cold water ΔT = 10.0 ° C. (100%), and the primary side cold water ΔT = 10.0 ° C. (100%). Further, since the secondary flow rate ΔT is 100%, the secondary flow rate ratio is 100% × 60% = 60%, which coincides with the secondary heat amount ratio 60%.
The calculation method of the primary flow rate in the example of FIG. 4 is as follows.
The load flow rate ratio is (253.8 + 10) /423=62.4%.
The load ratio takes a larger value of either the load flow rate ratio or the load heat amount ratio. That is,
Load ratio = MAX (load flow rate ratio, load heat ratio)
= MAX (62.4%, 60%) = 62.4%.
Further, the primary flow rate can be obtained by the product of the load ratio and the design flow rate. That is,
Primary flow rate = load ratio × design flow rate = 62.4% × 423 = 332.3 m ³ / h.
In addition, the bypass flow rate in the example of FIG. 4 is 10.0 m ³ / h, which matches the bypass flow rate estimated by the assumed value. Moreover, the secondary cold water going temperature in the example of FIG. 4 is 7 ° C., which is the same temperature as the cold water outlet temperature of the refrigerator. When the assumed value of the bypass flow rate is 10 m ³ / h, the energy consumption of the chilled water pump is slightly increased compared to the case where the bypass flow rate is 0 m ³ / h. Comfort in the operation of the machine is improved.

２次側冷水ΔＴが１２０％の場合には、２次側冷水ΔＴ＝１２．０℃（１２０％）、１次側冷水ΔＴ＝１０．０℃（１００％）となる。また、２次流量比率は、２次側冷水ΔＴが１００％の場合と比べて、２１１．５ｍ^３／ｈ÷４２３．０ｍ^３／ｈ×１００＝５０％となり、２次熱量比率６０％よりも小さくなる。
図５の例での１次流量の算出方法は下記の通りである。
負荷流量比率は、（２１１．５＋１０）／４２３＝５３．２％である。
負荷比率は、負荷流量比率と負荷熱量比率のいずれか大きい方の値をとる。すなわち、
負荷比率＝ＭＡＸ（５３．２％，６０％）＝６０．０％である。
また、１次流量は、負荷比率と設計流量との積で求めることができる。すなわち、
１次流量＝負荷比率×設計流量＝６０．０％×４２３＝２５３．８ｍ^３／ｈである。
また、図５の例でのバイパス流量は、１次流量（２５３．８ｍ^３／ｈ）−２次流量（２１１．５ｍ^３／ｈ）＝４２．３ｍ^３／ｈである。２次側冷水ΔＴが大きいほど、往ヘッダから還ヘッダへのバイパス量も大きくなる。また、図５の例での２次冷水往温度は７℃であり、冷凍機の冷水出口温度と同じ温度となる。 Next, the case where the secondary side cold water ΔT is 120% will be described with reference to FIG. The flow rates of the primary and secondary chilled water, the primary chilled water ΔT and the secondary chilled water ΔT, and the amount of heat in the example of FIG.

When the secondary cold water ΔT is 120%, the secondary cold water ΔT = 12.0 ° C. (120%) and the primary cold water ΔT = 10.0 ° C. (100%). The secondary flow rate ratio is 211.5 m ³ /h÷423.0 m ³ / h × 100 = 50% compared to the case where the secondary cold water ΔT is 100%, which is more than the secondary heat amount ratio 60%. Get smaller.
The calculation method of the primary flow rate in the example of FIG. 5 is as follows.
The load flow rate ratio is (211.5 + 10) /523=53.2%.
The load ratio takes a larger value of either the load flow rate ratio or the load heat amount ratio. That is,
Load ratio = MAX (53.2%, 60%) = 60.0%.
Further, the primary flow rate can be obtained by the product of the load ratio and the design flow rate. That is,
Primary flow rate = load ratio × design flow rate = 60.0% × 423 = 253.8 m ³ / h.
Further, the bypass flow rate in the example of FIG. 5 is the primary flow rate (253.8 m ³ / h) −secondary flow rate (211.5 m ³ /h)=42.3 m ³ / h. The larger the secondary chilled water ΔT, the greater the amount of bypass from the forward header to the return header. Moreover, the secondary cold water going temperature in the example of FIG. 5 is 7 ° C., which is the same temperature as the cold water outlet temperature of the refrigerator.

２次側冷水ΔＴが８０％の場合には、２次側冷水ΔＴ＝８．０℃（８０％）、１次側冷水ΔＴ＝１０．０℃（１００％）となる。また、２次流量比率は、２次側冷水ΔＴが１００％の場合に比べて、３１７．２ｍ^３／ｈ÷４２３．０ｍ^３／ｈ×１００＝７５％となり、２次熱量比率６０％よりも大となる。
図６の例での１次流量の算出方法は下記の通りである。
負荷流量比率は、（３１７．２＋１０）／４２３＝７７．３％である。
負荷比率は、負荷流量比率と負荷熱量比率のいずれか大きい方の値をとる。すなわち、
負荷比率＝ＭＡＸ（７７．３％，６０％）＝７７．３％である。
また、１次流量は、負荷比率と設計流量との積で求めることができる。すなわち、
１次流量＝負荷比率×設計流量＝７７．３％×４２３＝３２７．０ｍ^３／ｈである。
また、図６の例でのバイパス流量は１０．０ｍ^３／ｈであり、想定値で見込んだバイパス流量に一致する。図６の条件においても、還ヘッダから往ヘッダへの逆流は生じない。また、図６の例での２次冷水往温度は７℃であり、冷凍機の冷水出口温度と同じ温度となる。 Moreover, based on FIG. 6, the case where secondary side cold water (DELTA) T is 80% is demonstrated. The flow rates of the primary and secondary chilled water, the primary chilled water ΔT and the secondary chilled water ΔT, and the amount of heat in the example of FIG.

When the secondary side cold water ΔT is 80%, the secondary side cold water ΔT = 8.0 ° C. (80%), and the primary side cold water ΔT = 10.0 ° C. (100%). The secondary flow rate ratio is 317.2 m ³ /h÷423.0 m ³ / h × 100 = 75% compared to the case where the secondary cold water ΔT is 100%, which is more than the secondary heat amount ratio 60%. Become big.
The calculation method of the primary flow rate in the example of FIG. 6 is as follows.
The load flow rate ratio is (317.2 + 10) /423=77.3%.
The load ratio takes a larger value of either the load flow rate ratio or the load heat amount ratio. That is,
Load ratio = MAX (77.3%, 60%) = 77.3%.
Further, the primary flow rate can be obtained by the product of the load ratio and the design flow rate. That is,
Primary flow rate = load ratio × design flow rate = 77.3% × 423 = 327.0 m ³ / h.
In addition, the bypass flow rate in the example of FIG. 6 is 10.0 m ³ / h, which matches the bypass flow rate estimated by the assumed value. Even in the condition of FIG. 6, no reverse flow from the return header to the forward header occurs. Moreover, the secondary cold water going temperature in the example of FIG. 6 is 7 ° C., which is the same temperature as the cold water outlet temperature of the refrigerator.

As described above, in the present embodiment, a large value of either the secondary chilled water load calorie ratio or the secondary chilled water flow rate ratio is set as a calculation reference value as a new index (control parameter) called the secondary chilled water load ratio. That is, in the control in the present embodiment, the calculation of the secondary load state can be simplified by converting physical quantities having different dimensions of heat quantity and flow rate into percentages and treating them in the same dimension. In the control according to the present embodiment, the number control of the heat sources and the variable flow rate control of the primary chilled water can be realized simultaneously based on the index of the secondary chilled water load factor.
Further, for example, when controlling the number of heat sources, the control logic according to the method of the present embodiment is compared with the case of performing compensation control in which the number of heat sources is increased based on the flow rate and the number of heat sources is decreased based on the amount of heat. Can be simplified. Therefore, in the case of the method of the present embodiment, it becomes easier to develop and maintain the controller of the heat source control system as compared with the conventional case.

Further, for example, when controlling the number of heat sources, the control logic according to the method of the present embodiment is compared with the case of performing compensation control in which the number of heat sources is increased based on the flow rate and the number of heat sources is decreased based on the amount of heat. As a result, the number of heat sources is not easily changed. Therefore, it is possible to perform control for reducing disturbance due to forced ON / OFF due to temperature and improving the energy saving and comfort of air conditioning.
In addition, according to the present embodiment, the secondary load state is displayed as a percentage, so that the primary chilled water flow rate> secondary regardless of the difference in the primary pump method / secondary pump method and the secondary chilled water temperature difference depending on the site. The cold water flow rate can be controlled at an appropriate flow rate.
Moreover, according to this embodiment, since the bypass flow rate from the forward header to the return header is also reduced as compared with the conventional case, the power consumption of the primary pump can be reduced.

FIG. 7 shows a second embodiment of the present invention.
In this embodiment, an example in which the heat source control system according to the present invention is applied to a primary pump system is shown.
The heat source control system includes four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator (heat source machine R4) 11d, forward header 27, return A header 29 and two air conditioners (AHU) 49a and 49b are provided.

  The four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator (heat source machine R4) 11d are supplied with a heat source start / stop command and a cold water outlet temperature from the PLC. SP is input. The four refrigerators (heat source machine R1) 11a, the refrigerator (heat source machine R2) 11b, the refrigerator (heat source machine R3) 11c, and the refrigerator (heat source machine R4) 11d have a heat source operation state, a heat source failure state, and The light load operation state is output to the PLC.

  Between the four refrigerators (heat source machine R1) 11a, the refrigerator (heat source machine R2) 11b, the refrigerator (heat source machine R3) 11c, the refrigerator (heat source machine R4) 11d and the forward header 27 are four primary. The side cold water outgoing pipes 13a, 13b, 13c, and 13d are connected to each other. Refrigerator outlet cold water temperature sensors 15a, 15b, 15c, and 15d are provided in the primary side cold water outgoing pipes 13a, 13b, 13c, and 13d. The temperature PV of the refrigerator outlet cold water temperature sensor 15a, 15b, 15c, 15d is output to the PLC.

  Between the four refrigerators (heat source machine R1) 11a, the refrigerator (heat source machine R2) 11b, the refrigerator (heat source machine R3) 11c, the refrigerator (heat source machine R4) 11d and the return header 29 are four primary. The side cold water return pipes 17a, 17b, 17c, and 17d are connected to each other. The four primary chilled water return pipes 17a, 17b, 17c, and 17d are directed from the return header 29 to the four refrigerators (heat source machines) 11a, 11b, 11c, and 11d, and the heat source flow meters 19a, 19b, and 19c. , 19d, cold water pumps (primary pumps) 21a, 21b, 21c, 21d, and refrigerator inlet cold water temperature sensors 23a, 23b, 23c, 23d, respectively. The measured values of the refrigerator inlet cold water temperature sensors 23a, 23b, 23c, and 23d are output to the PLC.

The flow rate PV of the heat source flow meter 19a, 19b, 19c, 19d is output to the flow rate indicating controller 25a, 25b, 25c, 25d for flow rate control. The flow rate indicating controllers 25a, 25b, 25c, and 25d receive the flow rate SP from the PLC, and adjust the rotational speeds of the cold water pumps (primary pumps) 21a, 21b, 21c, and 21d so that the flow rate PV becomes the flow rate SP. INV is controlled and varied.
The forward header 27 and the return header 29 are connected via an inter-header bypass path 31 provided with an inter-header differential pressure regulating valve 33. The opening of the inter-header differential pressure adjusting valve 33 is controlled by a differential pressure control indicating controller 35. The indicator controller 35 for differential pressure control opens and closes the inter-header differential pressure adjustment valve 33 based on the estimated terminal differential pressure PV measured by the differential pressure gauge 37 that measures the differential pressure between the forward header 27 and the return header 29. To control. The estimated terminal differential pressure PV measured by the differential pressure gauge 37 and the opening degree instruction value from the differential pressure control instruction controller 35 are output to the PLC.

  Thus, in this embodiment, four refrigerators (heat source machine R1) 11a, refrigerator (heat source machine R2) 11b, refrigerator (heat source machine R3) 11c, refrigerator (heat source machine R4) 11d, The primary side of the heat source is connected by the primary side cold water outgoing lines 13a, 13b, 13c, 13d, the forward header 27, the return header 29, the four primary side cold water return pipes 17a, 17b, 17c, 17d, and the like. It is configured.

On the other hand, between the forward header 27 and the return header 29, the secondary side cold water water passage 39 connecting the forward header 27 and the air conditioners (49 a, 49 b), the air conditioner (49 a, 49 b), and the return header 29. And a secondary-side cold water return water channel 41 is provided, which constitutes the secondary side of the heat source. The secondary chilled water outlet 39 is branched into two pipes of the two secondary chilled water systems 43 c, and the two secondary chilled water systems 43 c merge into the secondary chilled water return channel 41.
The two secondary chilled water systems 43c include load inlet temperature sensors 45a and 45b, two-way valves 47a and 47b, an air conditioner (AHU1) 49a, an air conditioner (AHU2) 49b, and load outlet temperature sensors 51a and 51b. , Load side flow meters 53a and 53b are respectively provided. The measured values of the load inlet temperature sensors 45a and 45b and the load outlet temperature sensors 51a and 51b are output to the PLC.

  A free cooling branch chilled water pipe 55 that is thermally connected to the free cooling cooling tower 59 via a free cooling heat exchanger 57 is connected to the secondary side cold water return water path 41 at two points, a branch point and a junction. Yes. The free cooling branch chilled water pipe 55 is connected to the free cooling flow meter 61, the free cooling chilled water pump 63, and the free cooling heat exchanger inlet temperature sensor from the branch point with the secondary side chilled water return channel 41 toward the free cooling heat exchanger 57. 65. The free cooling flow rate PV measured by the free cooling flow meter 61 is output to the flow control flow rate indicating controller (FIC) 67, and the free cooling flow rate PV is output from the flick flow rate indicating controller 67 to the PLC. Further, the free cooling flow rate SP is input from the PLC to the flicker flow rate indicating controller 67. The flick flow rate indicating controller 67 controls the number of rotations of the free cooling chilled water pump 63 by controlling the free cooling chilled water pump inverter INV so that the free cooling flow rate PV becomes the free cooling flow rate SP. A free cooling heat exchanger outlet temperature sensor 69 is provided in the free cooling branch chilled water pipeline 55 on the downstream side of the free cooling heat exchanger 57. The measured values of the free cooling heat exchanger inlet temperature sensor 65 and the free cooling heat exchanger outlet temperature sensor 69 are output to the PLC.

A free-cooling cooling tower outlet temperature sensor 73 and a free-cooling water pump 75 are provided in the free-fluid circulation water passage 71 that connects the free-cooling heat exchanger 57 and the free-cooling cooling tower 59. The flick cooling water pump 75 includes an inverter INV, and the rotation speed of the flick cooling water pump 75 controls the inverter INV by the output of the instruction controller 77 for temperature control based on the measurement value of the free cooling heat exchanger outlet temperature sensor 69. It is adjusted by doing.
The free cooling cooling tower 59 is cooled by a cooling tower fan 81 provided with an inverter INV. The number of revolutions of the cooling tower fan 81 is adjusted by controlling the inverter INV by the output of the temperature control instruction controller 79 based on the measured value of the free cooling cooling tower outlet temperature sensor 73.
Also in the present embodiment, the return water free cooling is configured by the flick circulation water channel 71 and the free cooling branch chilled water pipe 55 which are thermally connected via the free cooling heat exchanger 57.

  Also in the present embodiment, the PLC is connected to each of the air conditioners 49a and 49b, and the air conditioner inlet side forms a part of the secondary side cold water supply channel 39 and the air conditioner outlet side forms a part of the secondary side cold water return channel 41. The total value of the load flow rate measurement PV of the secondary side chilled water system composed of the 1-system chilled water pipe 43a and the 2-system chilled water pipe 43b and the estimated value of the flow rate of the inter-header bypass path 31 is expressed as four refrigerators. (Heat source machine R1) 11a, chiller (heat source machine R2) 11b, refrigeration machine (heat source machine R3) 11c, chiller (heat source machine R4) 11d divided by the total value of the design flow rate and chilled water load flow rate as a percentage display Calculate the ratio. In addition, the PLC calculates the load calorific value of the secondary chilled water system composed of the 1-system chilled water pipe 43a and the 2-system chilled water pipe 43b, the four refrigerators (heat source machine R1) 11a, and the refrigerator (heat source machine R2). 11b, the cold water load calorie | heat amount ratio which is divided by the total value of the design calorie | heat amount of the refrigerator (heat source machine R3) 11c, and the refrigerator (heat source machine R4) 11d is displayed as a percentage display. The PLC uses the larger value of the chilled water load flow rate ratio and the chilled water load heat rate ratio as the secondary chilled water load factor, and based on this secondary chilled water load factor, controls the number of heat sources or changes the primary chilled water flow rate. It is configured to perform control.

  The control of the heat source control system described in the first embodiment can be applied regardless of the primary pump system / secondary pump system. That is, the control of the heat source control system of the second embodiment shown in FIG. 7 is performed by the same method as that described in FIGS. 2 to 6 of the first embodiment. Therefore, also in this embodiment, there can exist the same effect as 1st Embodiment.

(Supplementary items of the embodiment)
In the above description of the first embodiment and the second embodiment, the case of the cooling operation by the circulation of the cold water has been described for the sake of simplicity. However, according to the present invention, the cold water is replaced with the hot water, and the heating operation by the circulation of the hot water (the reverse operation of the cooling operation) can be naturally performed. Control in this case may be performed by replacing cold water with hot water in the description of FIGS. 2 to 6 of the first embodiment.
In the present embodiment, the case where the cold water required heat amount SP is obtained using the return water free cooling method using the free cooling cooling tower 59 has been described. However, the present invention is not limited to this, and the free cooling cooling tower 59 is provided. It is also established when the return water free cooling method used is not used. In that case, in the control flow shown in FIG. 2, the chilled water required heat amount SP may be obtained from the chilled water load heat amount PV.

11a, 11b, 11c, 11d Refrigerator (heat source machine R1)
13a, 13b, 13c, 13d Primary chilled water outgoing pipes 15a, 15b, 15c, 15d Refrigerator outlet cold water temperature sensors 17a, 17b, 17c, 17d Primary chilled water return pipes 19a, 19b, 19c, 19d, heat source Flow meter 53a, 53b, 61 Load side flow meter, free cooling flow meter 21a, 21b, 21c, 21d Chilled water pump (primary pump)
23a, 23b, 23c, 23d, refrigerator inlet cold water temperature sensors 45a, 45b, load inlet temperature sensors 51a, 51b, load outlet temperature sensors 65, 69 free cooling heat exchanger inlet (outlet) temperature sensors 25a, 25b, 25c, 25d Flow rate indicating controller 27 Outgoing header 29 Return header 31 Inter-header bypass passage 33, 47a, 47b, 89 Control valve 35 Indicating controller 37 for differential pressure control Differential pressure meter 39 Secondary side cold water outgoing channel 41 Secondary side cold water return Water channel 43a 1 system cold water pipe 43b 2 system cold water pipe 47 Cold water return water channels 49a, 49b Air conditioner 55 Free cooling branch cold water pipe 57 Free cooling heat exchanger 59 Free cooling cooling tower 63 Free cooling cold water pumps 77, 79 For temperature control Indicator controller 83 Second forward header 85a Primary cold water pump 85b Secondary cold water pump Flop 87 pipe

Claims (4)

A heat source,
A first outgoing header connected to the cold water outlet side of the heat source via a primary side cold water outgoing line;
A return header connected to the cold water inlet side of the heat source via a primary cold water return pipe provided with a primary cold water pump in the middle;
An inter-header bypass path connected between the first forward header and the return header;
A second forward header connected to the first forward header via a secondary chilled water pump;
A secondary chilled water outbound conduit and a secondary chilled water return conduit connected between the second outbound header and the return header, each having an air conditioner;
A controller connected to the heat source and the primary chilled water pump;
A discharge pressure control valve for controlling the discharge pressure of the secondary chilled water pump;
With
The controller is
The total value of the load flow rate measurement value of the load side flow meter installed in either the secondary side cold water outbound pipeline or the secondary side cold water return pipeline and the estimated value of the flow rate flowing through the header bypass path , Calculate the cold water load flow rate ratio expressed as a percentage by dividing by the total design flow rate of the heat source,
Multiplying the difference between the measured values of the load outlet temperature sensor and the load inlet temperature sensor installed in the secondary chilled water outgoing pipeline and the secondary chilled water return pipeline, respectively, and the load flow rate measured value of the load side flow meter Divide the calculated load calorie measurement value by the total value of the design heat quantity of the heat source to calculate the cold water load calorie ratio expressed as a percentage,
The larger value of the chilled water load flow rate ratio and the chilled water load calorie ratio is the chilled water load factor,
A heat source control system that performs at least one of the number control of the heat sources and the flow control of the heat sources by the primary chilled water pump flow rate control based on the cold water load factor. A heat source,
A forward header connected to the cold water outlet side of the heat source via a primary cold water outgoing line;
A return header connected to the cold water inlet side of the heat source via a primary cold water return pipe provided with a primary cold water pump in the middle;
An inter-header bypass path connected between the forward header and the return header;
A secondary chilled water outgoing line and a secondary chilled water return pipe connected between the forward header and the return header, each having an air conditioner;
A controller connected to the heat source and the primary chilled water pump;
Said 1 which has the head for the pressure loss of said heat source, said primary side cold water outgoing line, said primary side cold water return line, said air conditioner, secondary side cold water outgoing line, and secondary side cold water return line The next cold water pump,
With
The controller is
The total value of the load flow rate measurement value of the load side flow meter installed in either the secondary side cold water outbound pipeline or the secondary side cold water return pipeline and the estimated value of the flow rate flowing through the header bypass path , Calculate the cold water load flow rate ratio expressed as a percentage by dividing by the total design flow rate of the heat source,
Multiplying the difference between the measured values of the load outlet temperature sensor and the load inlet temperature sensor installed in the secondary chilled water outgoing pipeline and the secondary chilled water return pipeline, respectively, and the load flow rate measured value of the load side flow meter Divide the calculated load calorie measurement value by the total value of the design heat quantity of the heat source to calculate the cold water load calorie ratio expressed as a percentage,
The larger value of the chilled water load flow rate ratio and the chilled water load calorie ratio is the chilled water load factor,
A heat source control system that performs at least one of the number control of the heat sources and the flow control of the heat sources by the primary chilled water pump flow rate control based on the cold water load factor. A heat source,
A first outgoing header connected to the hot water outlet side of the heat source via a primary hot water outgoing line;
A return header connected to the hot water inlet side of the heat source via a primary hot water return pipe having a primary hot water pump in the middle;
An inter-header bypass path connected between the first forward header and the return header;
A second forward header connected to the first forward header via a secondary hot water pump;
A secondary-side hot water outgoing conduit and a secondary-side hot water return conduit connected between the second forward header and the return header, each having an air conditioner;
A controller connected to the heat source and the primary hot water pump;
A discharge pressure control valve for controlling the discharge pressure of the secondary hot water pump;
With
The controller is
The total value of the load flow rate measurement value of the load-side flow meter installed in either the secondary side warm water forward pipeline or the secondary side warm water return pipeline and the estimated value of the flow rate flowing through the inter-header bypass channel , Calculate the hot water load flow rate ratio expressed as a percentage by dividing by the total design flow rate of the heat source,
Multiplying the difference between the measured values of the load outlet temperature sensor and the load inlet temperature sensor respectively installed in the secondary side hot water outgoing line and the secondary side hot water return line and the load flow rate measured value of the load side flow meter The calculated load calorific value is divided by the total value of the design heat quantity of the heat source to calculate the hot water load calorie ratio displayed as a percentage,
The larger value of the warm water load flow rate ratio and the warm water load heat rate ratio is the warm water load factor,
Based on the hot water load factor, at least one of the number control of the heat sources and the flow control of the heat sources by the primary hot water pump flow rate control is performed. A heat source,
A forward header connected to the hot water outlet side of the heat source via a primary-side hot water outgoing line;
A return header connected to the hot water inlet side of the heat source via a primary hot water return pipe having a primary hot water pump in the middle;
An inter-header bypass path connected between the forward header and the return header;
A secondary-side hot water outgoing conduit and a secondary-side hot water return conduit connected between the forward header and the return header, each having an air conditioner;
A controller connected to the heat source and the primary hot water pump;
Said 1 which has the head for the pressure loss of said heat source, said primary side warm water outbound pipeline, said primary side warm water return pipeline, said air conditioner, secondary side warm water outbound pipeline, and secondary side warm water return pipeline Next hot water pump,
With
The controller is
The total value of the load flow rate measurement value of the load-side flow meter installed in either the secondary side warm water forward pipeline or the secondary side warm water return pipeline and the estimated value of the flow rate flowing through the inter-header bypass channel , Calculate the hot water load flow rate ratio expressed as a percentage by dividing by the total design flow rate of the heat source,
Multiplying the difference between the measured values of the load outlet temperature sensor and the load inlet temperature sensor respectively installed in the secondary side hot water outgoing line and the secondary side hot water return line and the load flow rate measured value of the load side flow meter The calculated load calorific value is divided by the total value of the design heat quantity of the heat source to calculate the hot water load calorie ratio displayed as a percentage,
The larger value of the warm water load flow rate ratio and the warm water load heat rate ratio is the warm water load factor,
Based on the hot water load factor, at least one of the number control of the heat sources and the flow control of the heat sources by the primary hot water pump flow rate control is performed.

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