JP2007024325A - Method of controlling heat medium transporting device in air conditioning heat source system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of controlling a heat medium transporting device in an air conditioning heat source system capable of reducing transporting power of the heat medium transporting device in the air conditioning heat source system. <P>SOLUTION: A rotational frequency control device 16 calculates stage-up rotational frequency Fk on the basis of a time to achieve desired rotational frequency of a rotational frequency control device 16 in stage-up starting of secondary pumps 14a-14d by an operation number control device 28, the rotational frequencies of the increased secondary pump and the secondary pump under operation are increased to the calculated rotational frequency Fk, and the rotational frequencies of the increased secondary pump and the secondary pump under operation are controlled to the rotational frequency in accordance with load target, after the lapse of a waiting time for stabilization in stage-up from the start of the operation of the increased pump. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for controlling a heat transfer device in an air-conditioning heat source system, and more specifically, controls the rotational speed of a secondary pump according to a load target when the secondary pump is started to increase or decrease. The present invention relates to a method for controlling a heat transfer device.

The pressurized water pump system disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2003-106731) is configured as follows. That is, a primary water pump that sends cold water or hot water from the return header to the first feed header via a refrigerator, a cold / hot water generator or a boiler, and cold water or hot water from the first feed header to the second feed header. A secondary water pump for sending, a flow sensor for measuring a flow rate from the second feed header to the return header, a differential pressure sensor for measuring a pressure difference between the second feed header and the return header, and a water pressure In a pressurized water pump system comprising a pressure sensor and a secondary water pump having an inverter, the fixed resistance of the entire system and the pipe based on the measurement signal of the flow sensor and the external input signal or the table of the data storage unit, Calculation based on the water supply pressure calculated by selecting the road constant and the constant value by the friction loss head calculation formula or the discharge pressure measured by the differential pressure sensor. It is characterized in that it comprises a secondary pump controller having an input calculation unit which determines the rotation speed of the motor.
JP 2003-106731 A

  In a general pressurized water pump system, the rotation speed of the secondary water pump is controlled by performing a calculation based on the water pressure value of the secondary pump and the discharge pressure measured by the differential pressure sensor. On the other hand, in the control method of the secondary pump disclosed in Patent Document 1, for example, when increasing the stage, the rotational speed of the increased secondary pump is increased to the same rotational speed as that of the operating secondary pump. Since the rotation speed of the secondary pump that is continuously operated is increased to the maximum (MAX%) and then changed to the rotation speed according to the load in any case, the increase stage start and the stop stage stop In both cases, the change in flow rate (number of revolutions) increases. For this reason, there has been a problem that the pressure fluctuation and flow fluctuation in the pipe line are widened, causing not only control disturbance on the air conditioner side but also energy loss.

  SUMMARY OF THE INVENTION An object of the present invention is to solve such conventional problems, and includes a heat source device, a load side device, a heat medium transport device corresponding to the heat source device and the load side device, and the heat medium transport device. In the air conditioning heat source system composed of a number control device that controls the number of operating secondary pumps and a rotation speed control device that controls the rotation speed, the pressure fluctuation and flow fluctuation width are reduced, and the conveyance power of the heat medium conveyance device Is to provide a method for controlling a heat transfer device in an air-conditioning heat source system capable of obtaining a greater energy saving effect.

  The premise of the present invention to solve the above problems is that a heat source device, a load side device, a primary pump provided as a heat transfer device corresponding to the heat source device and the load side device, and a plurality of units in parallel are provided. A secondary pump equipped with a rotational speed conversion device, a number control device for controlling the number of operating secondary pumps, and a rotational speed control device for controlling the rotational speed of the secondary pumps according to a load target. It is a control method of the heat carrier transport device in the air conditioning heat source system provided.

  In the control method of the heat transfer device in such an air conditioning heat source system, the first invention is characterized in that when the number control device starts at least the second or more secondary pumps, the rotation speed control device Based on the time required to reach the desired number of revolutions of the number control device, the number of revolutions at the time of step increase is calculated, and the number of revolutions of the increased secondary pump and the operating secondary pump changes to the calculated value. After the increased secondary pump stabilization wait time has elapsed from the start of operation of the increased secondary pump, the rotation speed of the increased secondary pump and the operating secondary pump is set to the rotation speed according to the load target. Is to control.

  In addition, in the control method of the heat transfer device in such an air conditioning heat source system, the second invention is characterized in that the rotation speed control device is configured so that the rotation speed control device can be used when the number of control devices continuously stops at least one secondary pump. The rotation speed at the time of step reduction is calculated based on the time required to reach the desired rotation speed of the rotation speed control device, and then the rotation speed of the secondary pump that is continuously operated is changed to the calculated value. Stop the operation of the reduced secondary pump or perform low-speed standby operation, and continue the operation after the reduced-stage stabilization waiting time has elapsed since the operation of the reduced secondary pump stopped or during low-speed standby operation. The rotational speed of the secondary pump is controlled to the rotational speed corresponding to the load target.

  As an example of the embodiment of the control method of the heat transfer device in the air conditioning heat source system according to the first invention, the secondary pump that is continuously operated is delayed by a predetermined time from the start of operation of the increased secondary pump. The rotational speed is changed to the calculated value.

  In addition, as an example of the embodiment of the control method of the heat transfer device in the air conditioning heat source system according to the second invention, the secondary pump that has been stepped down is delayed by a predetermined time from the stoppage or the low-speed standby operation, and continued. Changing the rotational speed of the operating secondary pump to the calculated value.

  Furthermore, as an example of the embodiment of the control method of the heat transfer device in the air conditioning heat source system according to the first and second inventions, the plurality of secondary pumps are provided with a rotation speed conversion device, and the rotation speed control device is Use to control the rotational speed of the secondary pump.

  According to the control method of the heat transfer device in the air-conditioning heat source system according to the first aspect of the invention, when the secondary pump starts to increase or decrease, the optimum rotation speed that minimizes the pressure fluctuation and flow fluctuation width Therefore, since the rotation speed is controlled in accordance with the actual load target after that, there is little loss of conveyance energy, and the operation cost can be reduced because of energy saving operation.

  Further, according to the control method of the heat transfer device in the air-conditioning heat source system according to the present invention, the state of the entire pipeline is awaited for stabilization by delaying a predetermined time from the start of operation of the increased secondary pump. Furthermore, the rotation speed of the secondary pump that is continuously operated is lowered to the calculated value, and the secondary pump that is continuously operated is delayed by a predetermined time from the stoppage of the reduced secondary pump or the low-speed standby operation. Since the control is performed so that the number of rotations of the pump is increased to the calculated value, changes in pressure and flow rate are small, and as a result, a stable control operation can be realized.

  The details of the method for controlling the heat medium transfer device in the air conditioning heat source system according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration explanatory diagram schematically showing the configuration of an air conditioning heat source system that implements a control method according to the present invention. An air conditioning heat source system 10 shown in FIG. 1 includes a heat source device 11 composed of cold / hot water generators 11a and 11b and a heat medium transport device 12 corresponding to the heat source device 11 at the suction port of each of the cold / hot water generators 11a and 11b. It includes cold and hot water primary pumps (hereinafter referred to as primary pumps) 12a and 12b connected by pipes.

  Each of the cold / hot water generators 11a and 11b has a discharge port connected to the water supply primary header 13 via a pipe line. The water supply primary header 13 includes four cold / hot water secondary pumps (hereinafter referred to as two pumps) provided in parallel. 14a, 14b, 14c, and 14d) are connected by pipe lines. These secondary pumps 14a, 14b, 14c, 14d are provided with rotational speed converters 15a, 15b, 15c, 15d such as inverters, for example. The rotational speeds of the secondary pumps 14a, 14b, 14c, 14d are as follows: The rotation speed control device 16 is changed by performing pulse amplitude modulation (PAM control) or pulse width modulation (PWM control) of the frequency by the rotation speed conversion devices 15a, 15b, 15c, and 15d.

  The discharge ports of these secondary pumps 14 a, 14 b, 14 c and 14 d are connected to the water supply secondary header 17. A conduit having a relief valve 18 is connected between the water supply primary header 13 and the water supply secondary header 17. The water supply secondary header 17 is connected to the cold / hot water inlet of the air conditioners 19a, 19b installed in parallel by two pipes. That is, two pipes branch from one pipe connected to the water supply secondary header 17, and each branch pipe is connected to the cold / hot water inlet of each air conditioner 19a, 19b. One ends of the pipes 20a and 20b are connected to the cold / hot water discharge ports of the air conditioners 19a and 19b, and two-way valves 21a and 21b are provided in the pipes 20a and 20b. The other ends of the pipes 20 a and 20 b are joined to a pipe 22, and the pipe 22 is connected to a return water secondary header 23.

  The return water secondary header 23 communicates with the return water primary header 25 via a conduit 24, and a flow rate sensor 26 is provided in the conduit 24. Three pipes 27a, 27b, and 27c extend from the return water primary header 25. One pipe 27a is directly connected to the water supply primary header 13, and the other two pipes 27b and 27c are respectively primary pumps. 12a and 12b. The air conditioning heat source system 10 configured as described above further includes a number control device 28 and a pressure sensor 29 is provided in the water supply secondary header 16.

  The aforementioned rotational speed control device 16 is electrically connected to the rotational speed conversion devices 15a to 15d of the secondary pumps 14a, 14b, 14c, and 14d, the flow rate sensor 26, the number control device 28, and the pressure sensor 29. The number control device 28 is electrically connected to each of the rotation speed conversion devices 15a to 15d, the flow sensor 26, and the relief valve 18.

  Next, the control method of the heat transfer device in the air conditioning heat source system according to the present invention will be described by taking the air conditioning heat source system 10 configured as described above as an example. For convenience of explanation, it is assumed that all pumps have the same capacity and the next pump is activated when there is a secondary load exceeding the capacity of one pump. In the air-conditioning heat source system 10 shown in FIG. 1, when there are four secondary pumps 14a to 14d and the range of the pump rotation speed is assumed to be 0 to 100%, one secondary pump is operated at 100%. When the flow rate is 25%, the load is 25%. In the case of such an air conditioning heat source system 10, the number control by the flow rate is as shown in FIG. That is, when the secondary flow rate (load) is up to 25%, the unit control device 28 controls to operate one secondary pump 14a (operator 1), and the secondary flow rate (load) is When it exceeds 50% and reaches 50%, control is performed so that one secondary pump 14a (operator 2) is increased in operation to one secondary pump 14a that is being operated.

  Furthermore, when the secondary flow rate (load) exceeds 75% and reaches 75%, another secondary pump 14c (operator 3) is increased in stage to the two secondary pumps 14a and 14b in operation. When the secondary flow rate (load) exceeds 75% and reaches 100%, the three secondary pumps 14a, 14b, and 14c in operation are replaced with another secondary pump. 14d (operator 4) is controlled to increase the stage. When the secondary-side flow rate (load) decreases, the number control device 28 performs control to reduce the number of operating units according to the decrease in the secondary-side flow rate (load), contrary to the above-described increase step. Actually, the four secondary pumps 14a to 14d (operators 1 to 4) are always increased or decreased by the number control device 28 according to the change of the secondary flow rate (load). It is controlled to the optimum number of operating units.

  As described above, the number control device 28 controls the operation of the secondary pump by selecting an appropriate number according to the change in the secondary flow rate (load). The number control device 16 controls the rotational speed of the secondary pump that is in operation and the secondary pump that has started to increase the stage, or the secondary pump that continues to operate after the stage is stopped. The present invention reduces the pressure fluctuation and the flow fluctuation when the secondary pump starts to increase or stops when the secondary flow (load) changes, so that the energy saving effect can be obtained. It is characterized by control of the number of rotations. Therefore, for the method of controlling the secondary pump rotational speed at the time of start-up or step-down stop accompanying a change in the secondary side flow rate (load), a flowchart of the control of the chilled / hot water secondary pump speed by the speed control device (Fig. 3, 4), state explanatory diagrams showing the operation state of the secondary pump (FIGS. 5 to 10), and pump rotational speed control operation explanatory diagrams according to the load target (FIG. 11, FIG. 12) I will explain it.

  The rotation speed control device 16 at the time of installation of the air-conditioning heat source system 10 is controlled at the time of normal startup processing and normal stop processing of the secondary pump as shown in the flowcharts of FIGS. The rotational speed is input as a set value (step S-1). That is, the rotation speed of the secondary pump in the normal startup process and the normal stop process, which will be described later, is determined in advance as a constant. Next, set values of secondary pump rotation speed calculation formulas (1) and (2), which will be described later, that is, inverter acceleration / deceleration time (TiI) at increasing stage, delay time (TiD) at increasing stage, and rotation speed conversion at decreasing stage The step-down inverter acceleration / deceleration time (TdI) and the step-down delay time (TdD) are input (step S-2).

  When the air conditioning heat source system 10 is operating in this state, the current number of operating secondary pumps (n) is acquired (step S-3). When a change occurs in the secondary-side flow rate (load), the number control device 28 selects an appropriate number of secondary pumps to operate according to the load and issues an operation instruction. Based on this information, the change (m) in the number of secondary pumps is acquired (step S-4). Then, a change in the number of secondary pumps operating before the change (n) and after the change (m) is determined (step S-5), and this determination includes the cases (1), (2), There are cases where neither (1) nor (2) is present. In the case of (1), when n = 0 changes to m ≧ 1 (when there is no secondary pump in operation, one or more secondary pumps start up), in the case of (2) n ≥1 unit changed to m> n units (increased start-up when there are one or more secondary pumps in operation), and it is divided into processing methods according to these cases (1) and (2) . Note that the case where neither of (1) and (2) is present is a case where there is no change in the secondary air conditioning load and it is not necessary to newly start up the secondary pump.

  In the case of (1), as described above, one or more secondary pumps are staged up from a state where there is no operating secondary pump. In other words, this is a state when the operation is started from the state where the air conditioning system is stopped. In such a case, the normal startup process is performed (step S-6), and step S-1 is performed. One secondary pump is started at the starting rotational speed set in (Step S-7).

  In the case of (2), there are one or more secondary pumps in operation, and at that time, the secondary flow rate (load) increases and one or more secondary pumps start up in stages. . In this case, the process at the time of starting the increased stage is performed (step S-8), and the rotational speed (Fm) of the secondary pump operated immediately before starting the increased stage and the increased stage immediately before starting the increased stage (here, The stage increasing machine is the rotation speed (Fw) of the secondary pump that is newly operated in the main operation in addition to the operating secondary pump (step S-9). The term “main operation operation” is used when the step-up machine is completely stopped until just before the step-up operation, but when a low-temperature standby operation is required because a small amount of cold / hot water in the piping is required. Therefore, it is used to distinguish from such low-speed operation during standby. Therefore, when the step increasing machine is performing the low-speed standby operation, the rotation speed (Fw) during the low-speed standby operation is acquired. If neither (1) nor (2) is obtained, the process directly proceeds from step S-5 to step S-12.

Next, the rotational speed Fk is calculated by the following calculation formula (1) for calculating the rotational speed of the secondary pump at the time of starting up the stage (step S-10).
(Equation 1)
Fk = [Fm + ((100 / TiI) × TiD)] / 2 (1)
In the secondary pump rotational speed calculation formula (1) at the time of starting the increased stage, Fk is the pump rotational speed (%) corresponding to the load target, and Fm is the rotational speed (%) of the operating pump immediately before starting the increased stage. , TiI is the acceleration / deceleration time by the inverter at the time of increasing stage, and TiD is the delay time at increasing stage (TiI ≧ TiD). The calculation method of the calculation formula (1) will be described in detail later.

  After that, the step-up machine started operation at the secondary pump speed Fk calculated by the above formula (1), and the operating secondary pump passed the step-up delay time (TiD). Later, the operation is continued at the pump rotation speed (Fk) obtained by the above formula (1) (step S-11) and the control of the secondary pump is continued (step S-12). And when a change occurs in the secondary side flow rate (load), the process returns to step S-3 again, and the process proceeds to step S-3 where the number of pumps operated (n) at that time is acquired. The general control steps at the time of starting up the secondary pump are as described above. Next, an outline of control steps when the secondary pump is stopped will be described with reference to the flowchart of FIG.

  In FIG. 4, steps S-1 to S-4 are steps common to the control at the time of starting the stage increase shown in FIG. 3, and these steps have already been described and will be omitted. If a change occurs in the secondary-side flow rate (load) during the operation of the air conditioning heat source system 10, the unit control device 28 selects an appropriate number of secondary pumps to be operated according to the load and issues an operation instruction. Based on the instruction information, a change in the number of secondary pumps operating before the change (n) and after the change (m) is determined (step S-5). In the case of step reduction, this determination may be (3), (4), or neither (3) nor (4). In case (3), n> m In case of (4) when changing from m ≧ 1 to m ≧ 1 (stepping down when there are one or more secondary pumps to continue operation), in case of (4), change from n ≧ 1 to m = 0 This is the time when there are no secondary pumps to continue (steps down to zero), and the processing methods are divided according to these cases (3) and (4). Note that the case where neither of (3) and (4) is present is a case where there is no change in the secondary-side air-conditioning load and no new reduction of the secondary pump is required.

  In the case of (3), that is, when the secondary flow rate (load) decreases and one or more secondary pumps stop and there are one or more secondary pumps that continue to operate at that time, the stage is reduced. A process at the time of stop is performed (step S-13), and the rotation speed (Fm) of the secondary pump that is operating immediately before the stage stop is acquired (step S-14).

Next, the rotational speed Fk is calculated by the following calculation formula (2) for calculating the rotational speed of the secondary pump at the time of step reduction stop (step S-15).
(Equation 2)
Fk = [Fm + (((− 100 / TdI) × TdD) +100)] / 2 (2)
In the rotational speed calculation formula (2) of the pump during continuous operation at the time of the speed reduction stop, Fk is the pump speed (%) according to the load target, and Fm is the speed of the operating pump immediately before the speed reduction stop. (%), TdI is the acceleration / deceleration time by the inverter at the time of step reduction, and TdD is the delay time at the step reduction (TdI ≧ TdD). The calculation method of the calculation formula (2) will be described in detail later.

  The secondary pump that is continuously operated after the stage reduction stop is operated at the secondary pump rotational speed Fk calculated by the above-described calculation formula (2) (step S-16). At that time, the secondary pump that has been step-down stopped may be completely stopped, but as described above, it may be operated at a low-speed standby because it is necessary to slightly flow the cold / hot water in the piping. In the latter case, a low-speed standby operation is performed at the stop speed set in step S-1. And when a change occurs in the secondary side flow rate (load), the process returns to step S-3 again, and the process proceeds to step S-3 where the number of pumps operated (n) at that time is acquired.

  In the case of (4), there are no secondary pumps that continue to operate (zero units). In other words, the air conditioners 19a and 19b are in a stopped state. In such a case, the normal stop process is performed (step S-17), and the cold and hot water in the pipe is slightly reduced as described above. When the low-speed standby operation is performed because it is necessary to flow in the low-speed operation, the low-speed standby operation is performed at the stop rotation speed set in step S-1 (step S-18). If neither (3) nor (4), the process proceeds directly from step S-5 to step S-12.

  The general control method of the secondary pump at the time of starting up the stage and at the time of stopping the stage of reduction is as described based on the two flowcharts shown in FIG. 3 and FIG. 4, but the control method according to the present invention is the same. For convenience of explanation, it is divided into two flowcharts, namely, at the time of increasing the stage and at the time of stopping the lowering. Actually, in step S-5, it is determined whether the stage is increased or stopped. Further, at the time of increased stage activation, either (1) or (2) and (1) and (2) The determination is made when neither of them is satisfied, and when the stage is stopped, it is determined if any of (3) and (4) and not (3) or (4), and the subsequent processing is performed.

  Next, a more specific operation state of the secondary pump at the time of starting to increase the stage and stopping to reduce the stage will be described with reference to FIGS. FIGS. 5 to 10 show the operating states of the secondary pumps 14a to 14d at the time of start-up and step-down stop in time series with the horizontal axis as a time axis. That is, in each of FIGS. 5 to 10, the transition (A) of the secondary flow rate (load) is shown in the upper part of the vertical axis direction, and the control state in the conventional air conditioning heat source system is shown in the middle part (rotation of the secondary pump). Number transition (B)), the lower part shows the rotational speed control operation state (C) according to one embodiment of the present invention as a change with time, and these changes, that is, states A1, B1, C1 5 as a group of 1, state A2, B2, C2 as a second group in FIG. 6, state A3, B3, C3 as a third group in FIG. 7, state A4, B4, C4 as a fourth group. FIG. 8 shows states A5, B5, and C5 as a fifth group, FIG. 9 shows states A6, B6, and C6 as a sixth group, and FIG. That is, each shown in FIGS. It has been changed to a time series of state.

  As indicated by the state A1 in the upper part of FIG. 5, when the secondary flow rate (load) is 0%, the operation of all four secondary pumps 14a to 14d is stopped. When the secondary flow rate (load) starts to increase from 0%, the unit controller 28 operates one secondary pump 14a (indicated as operating unit 1 in FIG. 5) as shown in the state C1, The secondary pump 14a (operating machine 1) is operated at an output of 100% by the rotation speed control device 16 from the operation start time to the stabilization time at the time of step increase, and then according to the secondary side flow rate (load). The pump rotation speed (frequency output) is controlled. That is, when the secondary flow rate (load) is 20% as shown in the state A1 of FIG. 5, the secondary side flow rate (load) is increased after the stabilization waiting time at the time of step increase as shown in the state C1. ) Is controlled to 80% (output). As described above, the rotational speed control when one secondary pump 14a starts operation is not particularly different between the conventional control (state B1) and the control according to the present invention.

  However, when the secondary flow rate (load) increases from 25% to 35% as shown in state A2 of FIG. 6, the operating secondary pump 14a controls the rotational speed as shown in state C2. The device 16 is operated with its output increased from 80% to a maximum of 100%, but the secondary flow rate at the maximum output of one secondary pump 14a is 25%, so the secondary pump 14a alone should cover it. Therefore, the unit control device 28 instructs the operation of the other secondary pump 14b (indicated as the operating unit 2 in FIG. 6) to start increasing the stage.

  At that time, the secondary pump 14b (operator 2) increased in stage is operated at the pump rotation speed Fk corresponding to the load target calculated by the above-described pump rotation speed calculation formula (1) at the time of increase start. The pump rotational speed Fk corresponding to the load target is obtained by substituting necessary information such as the rotational speed of the secondary pump immediately before the increase stage start by the rotational speed control device 16 into the above-described calculation formula (1). That is, when the number control device 28 instructs the secondary pump to start increasing from the information of the flow sensor 26 etc., the information is simultaneously input to the rotation speed control device 16 and receives the information signal to control the rotation speed. The device 16 calculates the pump rotation speed Fk corresponding to the load target for the secondary pump that starts increasing in stages based on the above-described calculation formula (1), and the rotation speed of the secondary pump 14b that starts increasing in stages. A signal is output to the converter 15b. On the other hand, the operating secondary pump 14a (operating machine 1) is operated at a maximum pump speed of 100% (MAX%) when the secondary pump 14b, which is the operating machine 2, is started to increase in stage. Keep only for hours. This predetermined time is referred to as “delay time at the time of step increase”, and this delay time at the time of step increase is TiD in the calculation formula (1) as described above.

  The secondary pump 14a (operating machine 1) in operation is lowered by the rotational speed control device 16 to the rotational speed Fk calculated by the calculation formula (1) when the delay time TiD at the time of increase elapses. And the operating machine 2 are operated at the same rotational speed. This calculation formula (1) is stored in the memory of the rotation speed control device 16, and when the unit control device 28 instructs the secondary pump to start increasing from the information such as the flow sensor 26, the information is the rotation speed control. At the same time, the numerical value necessary for the calculation formula (1) stored in the memory of the rotational speed control device 16 is substituted based on the information signal, and thereby the secondary pump after the start of the stage increase is started. The pump speed Fk corresponding to the load target is calculated as the speed and is output as a signal to the speed converters 15a and 15b of the secondary pumps 14a and 14b. The reason for controlling the rotation speed of the operating machine 1 that is continuously operated by delaying a predetermined time from the time when the operating machine 2 is increased is controlled by reducing the pressure change and the flow rate change in the secondary side pipe line. This is to stabilize the state.

  After the stage increase stabilization waiting time (TiS) has elapsed since the secondary pump 14b has started to increase the stage, the secondary pumps 14a and 14b are controlled to the number of rotations corresponding to the target load by normal rotation speed control. Is done. That is, when the target load is 35%, the output borne by one secondary pump is 17.5%, which is half of the target load, and therefore the output rotation speed of each secondary pump 14a, 14b. Respectively becomes 70%.

  In the case of such a step-up startup, in the conventional control method, as shown in the middle stage diagram in FIG. 6, that is, the state B2 in the transition of the rotation speed of the secondary pump in the conventional air-conditioning heat source device, the step-up startup is performed. The second secondary pump 14b (operator 2) starts operation at the maximum pump speed of 100% (MAX%) and maintains this state until the stabilization waiting time at the time of increasing the stage elapses. Therefore, both of the operating units 1 and 2 are operated at the maximum pump speed of 100% (MAX%) until the stabilization waiting time at the time of increase is elapsed.

  In the control in the conventional air-conditioning heat source system, as shown in the state B2 in FIG. 6, the maximum pumps for both the operating units 1 and 2 are from the point in time when the operating unit 2 is started up to the stabilization waiting time at the time of increasing the stage. Since it is operated at the number of revolutions and then controlled to the number of revolutions according to the target load, the range of pressure fluctuations and flow fluctuations in the pipe line increases, and as a result, it causes control disturbance on the air conditioner side. Or energy loss is great. However, in the control method according to the present invention, as described above, the operating unit 2 that starts increasing the stage is not operated at the maximum pump speed, but is operated while being controlled to the speed calculated from the calculation formula (1). Since the driving machine 1 is also operated by lowering the rotation speed calculated by the calculation formula (1) (resulting in the same rotation speed as the driving machine 2) when the delay time TiD at the time of the increase has elapsed since the start of the increase of the stage, The control disturbance on the air conditioner side due to pressure fluctuation and flow rate fluctuation is reduced, and operation with high energy saving effect is performed.

  Next, when the secondary pumps 14a and 14b (operators 1 and 2) are respectively operated at an output of 70%, the secondary flow rate (load) increases to 80% as shown in the state A3 of FIG. The case will be described. When the secondary flow rate (load) increases to 80%, the operating secondary pumps 14a and 14b have their pump rotation speeds increased from 70% to 70% by the rotation speed controller 16 as shown in the state C3 of FIG. It is raised to 100% of the driving. However, since the secondary flow rates at the maximum output of the two secondary pumps 14a and 14b are 25%, respectively, they cannot be covered by the secondary pumps 14a and 14b alone. In order to operate with the number corresponding to the number of the secondary pumps 14c and 14d (indicated as operating units 3 and 4 in FIG. 7), an increase in the number of stages is started.

  Also in this case, the two secondary pumps 14c and 14d that have been started up in stages are calculated by the above-described calculation formula (1) that calculates the pump rotation speed at the start up of the stage in the same manner as in the state C2 described above. It is controlled to operate at the rotational speed Fk. On the other hand, the operating secondary pumps 14a and 14b (operating units 1 and 2) are operated at a maximum output of 100% when the secondary pumps 14c and 14d as the operating units 3 and 4 are started up in stages. Is maintained for the delay time TiD at the time of step increase similarly to the state C2 of FIG. The secondary pumps 14a and 14b (operators 1 and 2) in operation are lowered by the rotational speed control device 16 to the rotational speed Fk calculated by the calculation formula (1) when the delay time at the time of increase has elapsed. The drivers 1 to 4 are operated at the same rotational speed.

  After the stage increase stabilization waiting time has elapsed since the start of the stage increase start, the secondary pumps 14a to 14d are controlled to the rotation speed corresponding to the target load by the normal rotation speed control. That is, when the target load is 80%, the output of one secondary pump is 1/4 of the target load, that is, 20%. Therefore, the rotation speed of each secondary pump 14a to 14d is Each is 80%.

  In the conventional control method in the case of such a step-up startup, as is apparent from the middle stage state B3 in FIG. 7, the third and fourth secondary pumps 14c, 14d (operators 3, 4) that have been stepped up. ) Starts operation at the maximum (100%) pump speed, and maintains this state until the stabilization waiting time at the time of increasing the stage elapses. Therefore, all of the operating units 1 to 4 are operated at a maximum pump speed of 100% until the stabilization waiting time at the time of increasing stage elapses, and then controlled to a speed corresponding to the target load. The fluctuation range is large, the control disturbance on the air conditioner side becomes large, and the energy loss is also large. However, in the control method according to the present invention, the operating units 3 and 4 that are to be stepped up are not operated at the maximum output, but are operated while being controlled at the rotation speed calculated from the calculation formula (1). 2 is also operated by lowering to the rotation speed calculated by the calculation formula (1) (resulting in the same rotation speed as that of the operating units 3 and 4) when the delay time TiD at the increase stage elapses from the start stage of the increase stage. The control disturbance on the air conditioner side due to pressure fluctuation and flow rate fluctuation is reduced, and operation with high energy saving effect is performed.

  Next, control when the secondary pump is stepped down will be described with reference to FIGS. 8, when the secondary flow rate (load) shows a tendency to fall below 75% to 60% as indicated by the state A4 in the upper stage, all four secondary pumps 14a to 14d are operated. Since there is no need, the number reduction control is performed by the number control device 28. That is, when the secondary flow rate (load) is less than 75%, the unit control device 28 stops the secondary pump 14d (operating machine 4) in a step-down manner as shown in the state C4.

  The secondary pumps 14a, 14b, and 14c that are in continuous operation are operated while maintaining the rotation speed immediately before the stage-reduction stop for a predetermined time. This predetermined time is referred to as a “delay time delay time”, and the step delay time is TdD in the above-described calculation formula (2). When this step-down delay time elapses, the secondary pumps 14a to 14c are operated at the pump speed Fk corresponding to the load target calculated by the following calculation formula (2). This calculation formula (2) is also stored in a storage device such as a memory of the rotation speed control device 16, and when the unit control device 28 instructs the secondary pump to stop the stage from the information such as the flow sensor 26, the information Is simultaneously input to the rotational speed control device 16 and a necessary numerical value is substituted into the calculation formula (2) stored in the memory of the rotational speed control device 16 based on the information signal, thereby continuing after the step reduction. A pump rotational speed Fk corresponding to the load target is calculated as the rotational speed of the secondary pump to be operated, and a signal is output to the currently operating secondary pumps 14a, 14b, and 14c.

  The reason for operating the secondary pumps 14a, 14b, 14c during continuous operation at the rotational speed immediately before the stage reduction stop for the stage reduction delay time when the stage of the secondary pump 14d is reduced is the secondary side This is because the pressure change and the flow rate change in the pipe line are reduced to stabilize the state in the pipe line. After the step-down stabilization waiting time has elapsed since the time when the secondary pump 14d has stopped stepping down, the secondary pumps 14a, 14b, 14c are controlled to the number of rotations corresponding to the target load by normal rotation number control. The That is, when the target load is 60%, the output borne by one secondary pump is 20%, which is 1/3 of the target load, and therefore the output of each secondary pump 14a, 14b, 14c. (Rotational speed) is 80%.

  In the case of such a stage reduction stop, in the conventional control method, as is apparent from the state B4 in the transition of the rotation speed of the secondary pump in the conventional air conditioning heat source system shown in the middle stage in FIG. The secondary pumps 14a, 14b, 14c (operators 1, 2, and 3) that are continuously operated after the step reduction stop of 14d (operator 4) start operation at the maximum pump speed (100%), and when the gear is reduced This state is maintained until the stabilization waiting time elapses. Accordingly, the operating units 1, 2, and 3 are operated at the maximum pump speed of 100% until the stabilization time at the time of step reduction elapses, and then controlled to the speed corresponding to the target load. The fluctuation range is large, the control disturbance on the air conditioner side becomes large, and the energy loss is large. However, in the control method according to the present invention, the operating units 1, 2, and 3 that are continuously operated after the stage reduction stop are not operated at the maximum pump rotational speed, but are controlled to the rotational speed calculated from the calculation formula (2). Therefore, the control disturbance on the air conditioner side due to the pressure fluctuation and the flow fluctuation is reduced, and the operation with high energy saving effect is performed.

  Next, when each of the secondary pumps 14a, 14b, and 14c is operated at a pump speed of 80%, the secondary flow rate (load) is reduced to 15% as shown in the state A5 of FIG. Then, since this secondary flow rate (load) can be sufficiently covered by the operation of one secondary pump, the unit controller 28 judges this and determines the two secondary pumps 14b, 14c ( The operating units 2 and 3) are controlled to stop step-down (see state C5). At that time, the continuously operated secondary pump 14a is operated by the rotational speed control device 16 while maintaining the rotational speed immediately before the stage reduction stop by the stage reduction delay time. Control is performed to operate at the rotational speed Fk calculated in (2).

  When the two secondary pumps 14b and 14c are stepped down, the secondary pump 14a that is continuously operating (the secondary pump 14d has already stopped operating) is stopped at the step reduction time. The reason for operating at the immediately preceding rotational speed is to reduce the flow rate change in the secondary side pipe line and to stabilize the state in the pipe line.

  After the step-down stabilization waiting time has elapsed since the time when the secondary pumps 14b and 14c stopped step-down, the secondary pump 14a is controlled to the number of rotations corresponding to the target load by normal rotation number control. That is, when the target load is 15%, the pump speed of one secondary pump is 25%, so the pump speed of the secondary pump 14a is 60%.

  In the case of such a step-up startup, in the conventional control method, as is apparent from the state B5 in the transition of the rotation speed of the secondary pump in the conventional air conditioning heat source system shown in the middle stage in FIG. One secondary pump 14a (operator 1), which is continuously operated after the stage reduction stop of 14b and 14c (operators 2 and 3), starts operation at the maximum (100%) pump speed, and when the stage is reduced This state is maintained until the stabilization waiting time elapses, and then the pump rotation speed is controlled according to the target load, so the pressure fluctuation and flow fluctuation range are large, and the control disturbance on the air conditioner side increases and energy loss occurs. Is big. However, in the control method according to the present invention, the operating machine 1 that is continuously operated after the stage reduction stop is not operated at the maximum pump speed, but is operated while being controlled at the speed calculated from the calculation formula (2). Therefore, driving with high energy saving effect will be performed.

  Furthermore, as shown in state A6 of FIG. 10, when the secondary flow rate (load) falls below 15% to 0% (air conditioners 19a and 19b are stopped), the operating secondary pump 14a is As shown in the state C6, the rotation speed control device 16 outputs 60% to 0%, in other words, the operation is stopped. As described above, when the secondary flow rate (load) becomes 0% during the operation of one secondary pump 14a and the secondary pump 14a stops step-down, the conventional control method and the present invention are applied. There is no particular difference in the control method.

  Next, a calculation method of the pump rotational speed calculation formula (1) at the time of increasing the stage start will be described. FIG. 11 shows a characteristic curve showing the transition of the pump rotation speed at the time of starting the increased stage. This characteristic curve is a partially enlarged view of the state C2 in FIG. In the characteristic diagram of FIG. 11, the horizontal axis (X axis) is time, the vertical axis (Y axis) is the pump rotational speed, and the pump rotational speed change curve in the secondary pump (referred to as “operator”) during continuous operation is shown. Reference numeral 30 denotes a pump rotational speed change curve in a secondary pump (referred to as “stage increaser”) that has been started up in stages. These operating units and step-up machines are provided with a rotation speed conversion device such as an inverter, for example, and the rotation speed conversion device 16 can be freely controlled by PAM control or PWN control by the rotation speed control device 16 to change the rotation speed. It is like that.

  FIG. 11 is an operation example when the pump rotation control range during operation is assumed to be MIN% to MAX%. When the operating unit is operating at its rated maximum pump speed (MAX), the secondary flow rate (load) increases and the unit controller 28 issues an instruction to start one secondary pump in stages. In this case, the step-up machine is drawn up almost vertically as if it were operating at a predetermined output (pump rotation speed Fk) simultaneously with the start of operation (solid line indicated by reference numeral 41). This is the same as in FIG. 6, but is for ease of understanding of the explanation. Actually, the rotational speed at the time of start-up of the step-up machine is a gentle curve drawn from the point A by the quadratic function curve by the rotational speed control device. It increases with a simple curve. However, in order to make the explanation easy to understand, it is assumed that it increases in a straight line as drawn by a dotted line 42 as approximately y = ax (a> 1). 100%) is reached. The time from point A to point B at this time is the inverter acceleration / deceleration time (Til) at the time of step increase. Since the inverter acceleration / deceleration time (Til) at the stage increase is a characteristic value of the secondary pump to be used, it is stored in advance as a constant in the rotation speed control device 16 in step S-2 as described in the flowchart of FIG. ing.

  The dotted line 42 is referred to as an “acceleration line during step increase” for convenience. The inclination angle θ of the accelerating line 42 at the time of step increase is 100 / Til because the time until the rotation speed reaches 0% to 100% is the inverter acceleration / deceleration time (Til) at step increase. Therefore, the inclination angle θ corresponds to the inclination a when y = ax. In this y = (100 / Til) · x, if the delay time (Tid) at the time of increase is substituted as x, the rotation speed of the point D on the acceleration line 42 at the time of increase is obtained. The rotational speed of the secondary pump during operation is lowered when the delay time at the time of increase has elapsed since the start of the operation of the step-up machine. The deceleration line at that time is inclined with respect to the acceleration line 42 at the time of increase. Only the direction is negative. The position (point C) where the speed increasing deceleration line 43 and the speed increasing acceleration line 42 intersect is the rotational speed Fk corresponding to the load target. At this time, since the triangle defining the region indicated by the oblique line in FIG. 11 is an isosceles triangle, the rotational speed Fm of the operating unit 1 in operation is added to y = (100 / Til) · Tid to obtain 2 If it is equally divided, the number of rotations of point C is calculated.

  On the other hand, FIG. 12 shows a characteristic curve with respect to the transition of the pump rotation speed during the continuous operation at the time of step reduction. This characteristic curve is a partially enlarged view of the state C4 in FIG. In the characteristic diagram of FIG. 12, the acceleration line at the time of step reduction is indicated by reference numeral 45, and the deceleration line at the time of reduction step is indicated by reference numeral 46. The secondary pump in operation (“operator”) is stopped at the point where the step-down device delay time (TdD) elapses after the step-down device stops operating (including the case of low-speed operation) (point E). , It is assumed that the rotational speed is gradually increased and reaches the rotational speed Fk (point F) corresponding to the load target. When the deceleration line 46 by the rotational speed converter passing through the point F is drawn, the inclination of the deceleration line 46 becomes −100 / TdI for the reason already explained at the time of starting the step increase, and the explanation is easy to understand. Therefore, when this is expressed by an equation of a linear function, y = (− 100 / TdI) × x. By substituting TdD, which is a delay time during step-down, into x, the number of revolutions (y1) from 100% to point G is calculated on the straight line represented by y = (− 100 / TdI) × x. . Therefore, the actual rotational speed at the point G is 100 (%) + (− 100 / TdI) × TdD.

  Since the slope of the acceleration line 45 at the time of reduction of the secondary pump described above is substantially the same with only a difference between positive and negative, the region indicated by the oblique line is an isosceles as in the transition of the pump speed at the start of the increase in stage. It becomes a triangle. Therefore, the point F is 2 etc. by adding the rotational speed (Fm) of the operating machine immediately before the reduction gear stops and the rotational speed at the point G [100 (%) + (− 100 / TdI) × TdD]. If you divide, it will be required. The calculation formula is Formula (2).

  As described above, according to the control method of the heat transfer device in the air-conditioning heat source system according to the present invention, the secondary pump is set in accordance with the load target when the secondary pump is started up or stopped. By controlling to the number of revolutions and then to the number of revolutions according to the actual load target, control disturbances on the air conditioner side due to pressure fluctuations and flow fluctuations are reduced, and energy loss is reduced and energy saving operation is performed. Cost can be reduced.

  Moreover, according to the control method of the heat transfer device in the air-conditioning heat source system according to the present invention, the rotation speed of the secondary pump that is continuously operated is calculated by delaying a predetermined time from the start of operation of the increased secondary pump. Control is performed to increase the rotation speed of the continuously operating secondary pump to the calculated value by delaying it by a predetermined time from when the secondary pump that has been stepped down is stopped or at low speed standby operation. Therefore, the change in the flow rate is small, and as a result, the control state can be stabilized.

BRIEF DESCRIPTION OF THE DRAWINGS Configuration explanatory drawing which shows roughly the structure of the air-conditioning heat-source system which implements the control method which concerns on this invention. The characteristic view which shows the state which controls the driving | operation number of a secondary pump with a number control apparatus. The flowchart which shows the secondary pump rotation speed control operation by the rotation speed control apparatus at the time of stage increase starting. The flowchart which shows secondary pump rotation speed control operation | movement by the rotation speed control apparatus at the time of a stage reduction stop. State explanatory drawing which shows the control state of the rotation speed in the secondary pump at the time of stage increase starting. State explanatory drawing which shows the control state of the rotation speed in the secondary pump at the time of stage increase starting. State explanatory drawing which shows the control state of the rotation speed in the secondary pump at the time of stage increase starting. State explanatory drawing which shows the rotation speed control state of the secondary pump during the continuous operation at the time of the stage reduction stop. State explanatory drawing which shows the rotation speed control state of the secondary pump during the continuous operation at the time of the stage reduction stop. State explanatory drawing which shows the rotation speed control state of the secondary pump during the continuous operation at the time of the stage reduction stop. The characteristic view which shows the secondary pump rotation speed control operation | movement according to the load target at the time of stage increase starting. The characteristic view which shows secondary pump rotation speed control operation | movement according to the load target at the time of a stage reduction stop.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Air-conditioning heat source apparatus 11 Heat source apparatus 11a, 11b Cold / hot water generator 12 Heat medium conveying apparatus 12a, 12b Primary pump 13 Water supply primary header 14a, 14b, 14c, 14d Secondary pump 15a, 15b, 15c, 15d Rotational speed converter 16 Rotational speed control device 17 Water supply secondary header 19a, 19b Air conditioner 26 Flow rate sensor 28 Number control device 29 Pressure sensor

Claims (5)

A heat source device, a load side device, a primary pump provided as a heat transfer device corresponding to the heat source device and the load side device, and a secondary pump provided in parallel with a rotation speed converter Control of the heat transfer device in the air-conditioning heat source system, comprising: a number control device that controls the number of operating secondary pumps; and a rotation speed control device that controls the rotation speed of the secondary pumps according to a load target In the way
When at least two or more of the secondary pumps are started up in stages by the number control device, the rotation speed control device increases based on the time required to reach the desired rotation speed of the rotation speed control device. Calculate the stage rotation speed, change the rotation speed of the increased secondary pump and the operating secondary pump to the calculated value, and increase the stage from the start of operation of the increased secondary pump. In the air conditioning heat source system, the rotational speed of the secondary pump that has been increased and the secondary pump that is in operation is controlled to a rotational speed that corresponds to a load target after the time stabilization waiting time has elapsed. Control method for heat transfer device.   2. The heat medium in the air conditioning heat source system according to claim 1, wherein the rotation speed of the secondary pump that is continuously operated is changed to the calculated value after a predetermined time delay from the start of operation of the secondary pump that has been increased. A control method of the transport device. A heat source device, a load side device, a primary pump provided as a heat transfer device corresponding to the heat source device and the load side device, and a secondary pump provided in parallel with a rotation speed converter Control of the heat transfer device in the air-conditioning heat source system, comprising: a number control device that controls the number of operating secondary pumps; and a rotation speed control device that controls the rotation speed of the secondary pumps according to a load target In the method
Based on the time until the rotational speed control device reaches the desired rotational speed of the rotational speed control device at the time of step-down stop in which at least one secondary pump is continuously operated by the number control device. Calculate the rotation speed at the time of step reduction, and then change the rotation speed of the secondary pump that is continuously operated to the calculated value and stop the operation of the secondary pump that has been stepped down or perform low-speed standby operation, After the stepped down stabilization waiting time has elapsed since the secondary pump that has been stepped down has stopped operating or has been in low-speed standby operation, the rotational speed of the secondary pump that is continuously operated is set to the number of revolutions according to the load target. A method for controlling a heat transfer device in the air conditioning heat source system.   4. The rotation speed of the secondary pump that is continuously operated is changed to the calculated value by delaying by a predetermined time from the stoppage of the stepped-down secondary pump or the low-speed standby operation. A method for controlling a heat transfer device in an air conditioning heat source system. The heat medium in the air-conditioning heat source system according to any one of claims 1 to 4, wherein the plurality of secondary pumps include a rotation speed conversion device, and the rotation speed of the secondary pump is controlled using the rotation speed control device. A control method of the transport device.

Images