JP2008309428A - Flow rate control device of heat source system and flow rate control method of heat source system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow rate control device of heat source system and a flow rate control method of heat source system, satisfying required thermal load and flow rate load, and easily preventing increase in power consumed by the heat source system. <P>SOLUTION: This flow rate control device of the heat source system includes: a plurality of heat source machines 3; a plurality of pumps 4 started and stopped with the corresponding heat source machines to deliver a heat medium to an external load; and a number of machines control part 11 for controlling the number of heat source machines 3 and pumps 4 to be operated based on the actual load applied to the heat source system 1, wherein the maximum delivery flow rate per unit time in at least one pump 4 is excess flow rate larger than the delivery flow rate of the heat medium at the maximum thermal load. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat source system flow control device and a heat source system flow control method suitable for use in a heat source system used for district cooling and heating, air conditioning in a factory, and the like.

  In the heat source system, which is a facility that sends cold / hot water produced by multiple heat source units to the demand side, unit control that controls the number of heat source units that are operated, and variable flow rate that changes the flow rate of cold / hot water that is sent to the demand side In many cases, the flow control of cold / hot water is performed in combination with the control.

  However, due to the characteristics of the heat exchanger arranged on the demand side, the temperature difference (ΔT) between the feed temperature and the return temperature may be smaller than the temperature difference assumed at the time of facility design. In this case, there is a problem that an extra heat source machine has to be operated in order to secure the flow rate of the cold / hot water.

As measures against such problems, only the pump that supplies cold / hot water to the demand side is operated additionally, the heat source unit that cools the cold / warm water is not additionally operated, and the flow rate of the cold / hot water flowing through the heat source unit is rated Overflow control for flowing more than the flow rate has been proposed (see, for example, Patent Documents 1 to 5).
JP 2004-245560 A Japanese Patent No. 3852185 Japanese Patent No. 3884718 Japanese Patent No. 3666167 Japanese Patent No. 3062644

As described above, the method in which only the pump is additionally operated and the heat source apparatus is not additionally operated has a problem that cold / hot water having a required temperature (feed temperature) cannot be supplied to the demand side.
In this case, the cold / warm water sent out by the pump that has been additionally operated passes through the heat source unit that is not being operated and is supplied to the demand side. That is, the cold / hot water is sent out at the return temperature, mixed with the cold / warm water set at the feed temperature by the operating heat source machine, and then fed to the demand side. Therefore, the cold / hot water sent to the demand side has a different temperature from the feed temperature, and there is a problem that it is difficult to control the feed temperature.

  On the other hand, in the above-described overflow control, the pump and the heat source device can be efficiently controlled when the temperature difference (ΔT) between the feed temperature and the return temperature is smaller than the temperature difference assumed at the time of facility design as described above. However, when the above-mentioned temperature difference is a temperature difference assumed at the time of equipment design, the pump is not subject to overflow control and is controlled at a fixed flow rate. There was a problem that the consumption power of became large.

Furthermore, when the above-described temperature difference is constant, variable flow rate control for controlling the flow rate of cold / hot water according to the demand-side heat load is also used.
However, in this variable flow rate control, when the return temperature is changed and the value of the temperature difference is changed, there is a problem that the heat load required by the demand side cannot be supplied.

  The present invention has been made to solve the above-described problems, and satisfies the required thermal load and flow load even when the thermal load and flow load required from the demand side fluctuate independently. An object of the present invention is to provide a heat source system flow rate control device and a heat source system flow rate control method capable of easily preventing an increase in power consumed by the heat source system.

In order to achieve the above object, the present invention provides the following means.
A flow control device for a heat source system of the present invention includes a plurality of heat source devices that cool or heat a heat medium flowing from an external load, and the heat source devices that are arranged corresponding to each of the plurality of heat source devices and together with the corresponding heat source devices Based on at least the actual load, a plurality of pumps that are started and stopped, the pumps that deliver the cooled or heated heat medium to the external load, a load calculation unit that calculates and calculates the actual load applied to the heat source system, A flow rate control unit that controls the flow rate of the heat medium delivered by a plurality of pumps, and a unit control unit that controls the number of operating heat source units and the number of pumps based on the actual load are provided, and at least one of the pumps The maximum delivery flow rate per unit time is an overflow rate that is higher than the delivery flow rate of the heat medium at the maximum heat load.

  According to the present invention, since the flow rate of the heating medium sent out by the pump is controlled based on at least the actual load, for example, when the temperature difference becomes small, the above-described heating medium is used to satisfy the required actual load. Control is performed to increase the flow rate. Here, in at least one pump, since the maximum delivery flow rate per unit time is an excessive flow rate, the flow rate of the heating medium is controlled to the excessive flow rate. Therefore, it is not necessary to increase the number of operating heat source units excessively with respect to the heat load required from an external load, that is, the actual load applied to the heat source unit, more specifically the heat source system, and increase the power consumption of the heat source system. Can be prevented.

  On the other hand, since the number of heat source units and pumps operated based on the actual load is controlled, when the actual load increases, the number of operated heat source units and pumps increases and when the actual load decreases. The number of heat source machines and pumps to be operated is reduced. Since the actual load is also a heat load required from an external load, by controlling the number of operating heat source units and pumps in this way, the required heat load described above can be achieved without excessively increasing the number of operating heat source units. Can be met.

  Since the heat source machine is started and stopped together with the pump corresponding to the heat source machine, the heat medium returned from the external load is not heated or cooled by the heat source machine and is not sent to the external load again. . In other words, since the heat medium is always heated or cooled by the heat source device and then sent to the external load, the heat medium sent to the external load is compared with the case where the pump and the heat source device are started and stopped separately. Can be controlled easily.

  In the above invention, a flow rate measuring unit for measuring a flow rate of the heat medium flowing through the external load, a feed temperature of the heat medium sent to the external load, and the heat medium returning from the external load to the heat source unit A temperature difference measuring unit that measures a temperature difference between the return temperature and the load calculating unit calculates the actual load from the measurement values obtained by the flow rate measuring unit and the temperature difference measuring unit. Preferably, the flow rate control unit controls the flow rate of the heat medium sent out by the plurality of pumps based on at least the actual load and the temperature difference.

  According to the present invention, since the flow rate of the heat medium sent out by the pump is controlled based on at least the actual load and the temperature difference, compared with the case where the flow rate of the heat medium is controlled based only on the actual load, An increase in power consumption of the heat source system can be effectively prevented.

  In the above invention, based on the temperature difference measured by the temperature difference measuring unit, a flow rate set value that is a set value of the flow rate of the heat medium sent out by the plurality of pumps is obtained, and the flow rate set value is obtained as the flow rate. It is desirable that a flow rate calculation unit for outputting to the control unit is provided, and the flow rate control unit controls the flow rate of the heat medium based on the input flow rate setting value.

  According to the present invention, since the flow rate of the heat medium sent out by the plurality of pumps is controlled based on the flow rate setting value of the heat medium obtained in the flow rate calculation unit, the flow rate of the heat medium can be reliably controlled. .

  In the above invention, it is desirable that the flow rate calculation unit makes the magnitude of the flow rate set value proportional to the actual load.

According to the present invention, the flow rate of the heat medium can be increased or decreased in proportion to the actual load for fluctuations in the actual load that does not require the number of operating heat source units to be increased or decreased. Can meet the required heat load.
Therefore, it is not necessary to excessively increase or decrease the number of operating heat source units with respect to fluctuations in actual load, and increase in power consumption of the heat source system can be prevented.

  In the above invention, the flow rate calculation unit is configured to set the flow rate when an operating temperature difference that is a temperature difference of the heat medium during operation is smaller than a set temperature difference that is a temperature difference of the heat medium during design. It is desirable to expand the upper limit value to a value corresponding to the overflow rate.

According to the present invention, when the operating temperature difference is smaller than the design temperature difference, the flow rate of the heat medium required to satisfy the actual load increases even if the actual load required by the external load is the same. . In such a case, it is possible to cope with the increased required flow rate of the heating medium by expanding the upper limit value of the flow rate setting value to a value corresponding to the above-described overflow rate.
Therefore, it is not necessary to excessively increase the number of operating heat source units with respect to the required actual load, and increase in power consumption of the heat source system can be prevented.

  In the above invention, when there are a plurality of sets of the heat source machine and the pump being operated, the flow rate calculation unit has a load factor substantially equal among the plurality of sets of the heat source machine and the pump being operated. It is desirable to obtain the flow rate setting value.

  According to the present invention, since the load factor is substantially equal between the operating heat source unit and the pump pair, the heads (heads) are approximately equal between these different sets. Therefore, the heat medium sent from each pump can be sent to an external load without being blocked by the heat medium sent from another pump.

  In the above invention, the number control unit, when the flow rate of the heat medium determined based on the actual load and the temperature difference exceeds the sum of the upper limit flow rate values of the heat source machine that is operating, It is desirable to start a new set of the heat source machine and the pump that are stopped.

  According to the present invention, for example, when the above-described temperature difference is reduced and the flow rate of the heat medium necessary for satisfying the actual load is increased, the necessary heat medium flow rate is determined by each heat source being operated. When the total of the upper limit flow rate values of the machine is exceeded, a new set of heat source machine and pump is started. Therefore, the flow rate of the heat medium per set of heat source units and pumps decreases, and the flow rate of the heat medium in the heat source units decreases. Then, compared with the case where the flow rate of the heat medium in a heat source machine is not reduced, the thickness reduction of the heat exchanger tube through which a heat medium flows can be prevented.

  In the above invention, it is preferable that the interval of the control timing of the flow rate of the heat medium by the flow rate control unit is shorter than the interval of the control timing of the number of operating heat source units by the number control unit.

According to the present invention, the control of the flow rate of the heat medium that can be changed in a short time compared to the start-up of the heat source device is performed at an interval shorter than the control timing of the number control of the heat source devices. On the other hand, the control of the number of operating heat source units, which requires time-consuming startup of the heat source unit as compared with the control of the flow rate of the heat medium, is controlled at an interval longer than the control timing of the flow rate of the heat medium.
Therefore, since it is not necessary to start up the heat source device in a short time, an excessive load is not applied to the heat source device, and failure of the heat source device can be prevented. Furthermore, short-term fluctuations in the actual load can be satisfied by controlling the flow rate of the heating medium at a short interval that is easy to control at short intervals and has a low risk of failure or the like.

  In the above invention, it is preferable that the control timing interval of the number of operating heat source units by the flow rate control unit is set based on the start characteristics of the heat source unit.

According to the present invention, it is not necessary to start up the heat source machine in a short time by setting the control timing interval of the number of operating heat source machines based on the startup characteristics of the heat source machine. The load is not applied, and the failure of the heat source machine can be prevented.
For example, when the heat source machine is a turbo refrigerator, the number of operating units is controlled at a shorter interval than in the case of an absorption refrigerator. On the other hand, when the heat source machine is an absorption refrigerator, the number of operating units is controlled at a longer interval than in the case of a turbo refrigerator.

  The flow rate control method of the heat source system of the present invention measures the flow rate of the heat medium sent from a plurality of heat source devices to the external load, and also feeds the temperature of the heat medium sent to the external load and the external load. A measurement step of measuring a temperature difference between the return temperature of the heat medium returning to the heat source unit, an actual load calculation step of calculating an actual load based on the temperature difference and the flow rate of the heat medium, A number calculation step for calculating the number of operating heat source units necessary for supplying the heat medium according to the load, and a flow rate setting value required for supplying the heat medium according to the actual load are calculated. If the number of operating heat source units determined by the set flow rate calculation step and the operation is greater than the number of operating heat source units being operated, the number of operating heat source units being operated is increased and operated. Of the heat source machine When the number is less than the number of rotations, based on the operation number control step of reducing the number of operating heat source devices in operation and the flow rate setting value obtained by calculation, the heat source devices are sent to the external load. And a flow rate control step for controlling the flow rate of the heat medium.

According to the present invention, since the flow rate of the heat medium sent out by the pump is controlled based on the flow rate setting value obtained by the calculation, for example, when the above-described temperature difference becomes small, the required actual load is reduced. In order to satisfy this, control is performed to increase the flow rate of the above-described heating medium based on the temperature difference.
On the other hand, since the number of heat source units and pumps operated based on the actual load is controlled, when the actual load increases, the number of operated heat source units and pumps increases and when the actual load decreases. The number of heat source machines and pumps to be operated is reduced.

  In this way, control of the flow rate of the heat medium and control of the number of operating heat source units and pumps can be performed with a single algorithm without using complicated switching logic, so the required heat load and flow rate While satisfy | filling load, the increase in the motive power which a heat-source system consumes can be prevented easily.

  According to the flow control device of the heat source system of the present invention, the heat source machine and the pump operated based on the actual load while controlling the flow rate of the heat medium sent out by the pump based on the flow rate set value obtained by the calculation Therefore, even if the heat load and flow load required from the external load on the demand side fluctuate independently, the required heat load and flow load are satisfied and the power consumed by the heat source system There is an effect that the increase can be prevented.

  According to the flow rate control method of the heat source system of the present invention, the control of the flow rate of the heat medium and the control of the number of operating heat source units and pumps are further performed by a single algorithm without using complicated switching logic. Therefore, it is possible to satisfy the required heat load and flow rate load and to easily prevent an increase in power consumed by the heat source system.

Hereinafter, a heat source system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
FIG. 1 is a schematic diagram illustrating the configuration of the heat source system according to the present embodiment.
In the present embodiment, the present invention will be described by applying the present invention to a heat source system 1 used as a heat source for factory facilities such as district heating and cooling and semiconductor factories.

As shown in FIG. 1, the heat source system 1 includes a plurality of heat source units 3 that heat or cool the heat medium, a plurality of pumps 4 that send the heat medium to the external load 5, and a heat medium and air. A plurality of external loads 5 for performing heat exchange, a flow rate measuring unit 7 for measuring the circulating flow rate of the heat medium, a temperature difference measuring unit 9 for measuring the temperature difference between the feed temperature and the return temperature of the heat medium, the heat source device 3 and A control unit (flow rate control unit, number control unit) 11 that controls the operation of the pump 4 is provided.
This embodiment will be described by applying to an embodiment in which water is used as a heat medium.

  The heat source unit 3 generates cold / hot water by heating or cooling water as a heat medium. In the present embodiment, the heat source unit 3 will be described by being applied to an embodiment in which a refrigerator is used as the heat source unit 3. As a refrigerator used, a turbo refrigerator, an absorption refrigerator, etc. can be illustrated, However, It does not specifically limit to these refrigerators.

The plurality of heat source units 3 are arranged in parallel as shown in FIG. 1, and the cold / hot water flowing out from these heat source units 3 is joined to one pipe and led to the external load 5. On the other hand, the cold / hot water flowing into the plurality of heat source units 3 is led from the external load 5 to one pipe, and then is diverted toward each heat source unit 3 and flows into the respective heat source units 3. . Furthermore, the heat source unit 3 is controlled to be started and stopped by the control unit 11.
In the present embodiment, description will be made by applying to an example in which the capacities of all the heat source devices 3 are substantially equal.

  The pump 4 is a pump that circulates the cold / hot water in the heat source system 1 by sucking the cold / warm water returned from the external load 5 and sending the cold / warm water again toward the external load 5. This is an inverter pump in which the delivery flow rate of cold / hot water is controlled.

The plurality of pumps 4 are arranged in one-to-one correspondence with the heat source unit 3 as shown in FIG. Cold / hot water returned from the external load 5 is guided to the pump 4, and the cold / hot water sent from the pump is guided to the heat source unit 3. Furthermore, the control signal which controls starting and a stop is input into each pump 4 while controlling the delivery flow rate of cold / hot water from the control part 11. FIG.
In the present embodiment, similarly to the heat source device 3, the description is applied to an example in which the capacities of all the pumps 4 are substantially equal. Therefore, the heads are substantially equal even between different sets of the heat source device 3 and the pump 4.

The above-described heat source unit 3 and pump 4 are set so that the upper limit value of the flow rate per unit time of the cold / hot water is an excessive flow rate higher than the flow rate of the cold / warm water at the maximum heat load in the heat source system 1.
Therefore, the maximum delivery flow rate per unit time in the pump 4 is an excessive flow rate that is higher than the delivery flow rate of the cold / hot water at the maximum heat load. On the other hand, the maximum flow rate per unit time in the heat source unit 3 is an excessive flow rate that is higher than the flow rate of the cold / hot water at the maximum heat load.

  When starting the pair of the heat source device 3 and the pump 4 corresponding to one to one, first, the pump 4 is started, and cold / hot water is caused to flow through the corresponding heat source device 3. After confirming that the cold / hot water has flowed into the corresponding heat source unit 3, the corresponding heat source unit 3 is started. Here, starting the heat source device 3 and the pump 4 in the above order is expressed as starting simultaneously.

The external load 5 is a heat exchanger that exchanges heat between cold / hot water heated or cooled by the heat source unit 3 and air to generate air at a predetermined temperature.
The plurality of external loads 5 are arranged in parallel as shown in FIG. 1, and the cold / hot water flowing out from these external loads joins one pipe and is led to the heat source unit 3. On the other hand, the cold / hot water flowing into the plurality of external loads 5 is diverted toward each external load 5 after being guided from the heat source unit 3 to one pipe.

  On the downstream side of the external load 5, flow rate control valves 6 that control the flow rate of the cold / hot water flowing through the external load 5 are arranged one-on-one with respect to the external load 5. In the present embodiment, description will be made by applying to an example in which a two-way valve is used as the flow control valve 6.

The flow rate measuring unit 7 measures the flow rate of cold / hot water returning from the external load 5 to the heat source unit 3. As shown in FIG. 1, the flow rate measuring unit 7 is arranged between the flow rate control valve 6 and the pump 4. Further, the flow rate measuring unit 7 outputs a measured value of the flow rate of the cold / hot water to the control unit 11.
In addition, as a flow measurement part 7, a well-known flow meter can be used and it does not specifically limit.

The temperature difference measuring unit 9 calculates the temperature difference between the feed temperature that is the temperature of the cold / hot water sent from the heat source device 3 to the external load 5 and the return temperature that is the temperature of the cold / hot water that returns from the external load 5 to the heat source device 3. It is to be measured. As shown in FIG. 1, the temperature difference measuring unit 9 is provided with a part for measuring the feed temperature in a pipe through which cold / hot water flows between the heat source unit 3 and the external load 5, and a part for measuring the return temperature is a flow rate measurement. It is provided in a pipe through which cold / hot water flows between the section 7 and the pump 4. Further, the temperature difference measuring unit 9 outputs a measured value of a temperature difference between the feed temperature and the return temperature of the cold / hot water to the control unit 11.
In addition, as the temperature difference measurement part 9, the thermometer which measures a well-known temperature difference can be used, and it does not specifically limit.

The control part 11 controls the start and stop of the heat source machine 3 and the pump 4 while controlling the delivery flow rate of the cold / hot water by the pump 4.
As shown in FIG. 1, the measurement value of the flow rate of the cold / hot water is input from the flow rate measurement unit 7, and the measurement value of the temperature difference of the cold / hot water is input from the temperature difference measurement unit 9 to the control unit 11. On the other hand, the control unit 11 outputs a control signal for controlling the start and stop of the heat source unit 3, and controls the pump 4 to control the flow rate of the cold / hot water and the start and stop of the pump 4. Control signals to be controlled are output.
A specific control method in the control unit 11 will be described in detail below.

Next, heat supply in the heat source system 1 of the present embodiment will be described with reference to FIG.
Here, the case where the cold generated by the heat source device 3 is supplied to the external load 5 and air is cooled in the external load 5 will be described.

  The cold / hot water of the heat source system 1 is supplied to the heat source unit 3 by an inverter-driven pump 4 as shown in FIG. The cold / hot water supplied to the heat source unit 3 is cooled to a predetermined temperature, for example, about 5 ° C., and flows out of the heat source unit 3.

The cold / hot water flowing out from the heat source unit 3 is guided to the external load 5 by the pipe, and flows into the external load 5 in which the flow rate control valve 6 is opened. The cold / hot water flowing into the external load 5 takes heat from the air and cools it.
In the external load 5, the cold / hot water takes heat from the air, and the temperature rises to a preset temperature, for example, about 15 ° C. Thereafter, the cold / hot water flows out of the external load 5 and passes through the flow control valve 6.

The cold / hot water that has passed through the flow rate control valve 6 passes through the flow rate measuring unit 7 and then flows into the pump 4 that is being operated. Thereafter, by repeating the above-described process, the cold heat generated by the heat source device 3 is supplied to the external load 5.
In addition, also when supplying the heat generated by the heat source device 3 to the external load 5, the heat is supplied to the external load 5 through the same process as described above, and thus the description thereof is omitted.

Next, the control of the flow rate of cold / hot water by the pump 4 and the control of the number of operating heat source units 3 and pumps 4, which are features of the present embodiment, will be described.
2 to 4 are flowcharts for explaining control of the pump and the heat source machine in the heat source system of FIG.

  When the heat source system 1 is operated, as shown in FIGS. 1 and 2, the control unit 11 acquires a measured value of the temperature difference (operating temperature difference, ΔT) from the temperature difference measuring unit 9, and A measured value of the flow rate (F) of the cold / hot water is acquired from the flow rate measuring unit 7 (measurement step, step S1).

When the measured values of the temperature difference (ΔT) and the flow rate (F) are acquired, the control unit 11 performs the following series of calculations.
First, based on the measured values of temperature difference (ΔT) and flow rate (F) acquired, the actual load (L) required in the external load 5 is calculated by the following formula (actual load calculating step, step S2). ).
L = ΔT × F

Next, based on the obtained actual load (L) and the rated capacity of the heat source unit 3, the proper number of operating units (n) is calculated by the following formula (number calculating step, step S3). Here, the proper number of operating units (n) is the number of operating heat source units 3 that can supply the amount of cooling heat that satisfies the obtained actual load without excess or deficiency.
n = L / (rated capacity)

Further, based on the obtained measured value of the temperature difference (ΔT), the obtained actual load (L), and the proper number of operating units (n), the set flow rate value (Fset) is calculated by the following formula (set flow rate) Calculation step, S4). Here, the set flow rate value (Fset) is the flow rate of cold / hot water obtained in each pump 4.
Fset = L / (ΔT × n)

When the set flow rate value (Fset) is obtained, the control unit 11 determines the magnitude relationship between the total value (Fmax) of the upper limit value of the flow rate in each operating heat source unit 3 and the set flow rate value (Fset). (Step S5).
When the set flow rate value (Fset) is larger than the total value (Fmax) of the flow rate upper limit values, as shown in FIG. 3, a new number of proper operation (n1) is calculated (step S6).
On the other hand, when the set flow rate value (Fset) is equal to or less than the total flow rate upper limit value (Fmax), as shown in FIG. 4, the total lower limit flow rate value (Fmin) in each operating heat source unit 3 is shown. And the set flow rate value (Fset) are determined (step S21).

First, a case where the number of proper operation (n1) is newly calculated (step S6) will be described.
Based on the calculated actual load (L), total value of flow rate upper limit value (Fmax), and measured value of temperature difference (ΔT), control unit 11 calculates a new proper number of operating units (n1) by the following formula. Is done.
n1 = L / (Fmax × ΔT)

When the new proper number of operating units (n1) is obtained, a new set flow rate value (Fset1) is then set based on the total value (Fmax) of the flow rate upper limit values (step S7).
Fset1 = Fmax

  On the other hand, as shown in FIG. 4, the magnitude relationship between the total value (Fmin) of the lower limit value of the flow rate in each operating heat source unit 3 and the set flow rate value (Fset) is determined (step S21). explain.

When the set flow rate value (Fset) is smaller than the lower limit total value (Fmin), the control unit 11 sets a new set flow rate value (Fset1) based on the lower limit total value (Fmin) ( Step S22).
Fset1 = Fmin

If the set flow rate value (Fset) is equal to or greater than the total value (Fmin) of the lower limit values, the already obtained set flow rate value (Fset) is set as a new set flow rate value (Fset1) (step S24).
Fset1 = Fset

Then, the already determined appropriate operation number (n) is set as a new appropriate operation number (n1) (step S23).
n1 = n

  When the new proper operation number (n1) and the new set flow rate value (Fset1) are set as described above, the control unit 11 operates the heat source machine 3 that is currently operated as shown in FIG. The number (N) is acquired, and the new appropriate number (n1) and the current number (N) are compared (operation number control step, step S8).

Specifically, when the new proper operation number (n1) is larger than the current operation number (N), the control unit 11 determines to start one set of the heat source unit 3 and the pump 4. (Step S9), it is stored that a determination to start is made.
On the other hand, when the new proper operation number (n1) is less than the current operation number (N), the control unit 11 determines to stop one set of the heat source unit 3 and the pump 4 (step S10). ), It is stored that the decision to stop is made.

When the above-described determination is stored, or when the new proper operation number (n1) is equal to the current operation number (N), the control unit 11 determines each value based on the new set flow rate value (Fset1). A control signal for controlling the pump 4 is output (flow rate control step, S11).
Each pump 4 to which the above-described control signal is input sends out the flow rate of cold / hot water based on the new set flow rate value (Fset1).

  Thereafter, returning to the above-described step S1, the same control steps are repeated. The repetition of these control steps is repeated in a short cycle of, for example, about 1 minute to several minutes, and each time the pump 4 is repeated, the flow rate of cold / hot water is controlled based on a new set flow rate value (Fset1).

  On the other hand, the number of operating heat source devices 3 and pumps 4 is performed in a long cycle of, for example, about 30 minutes to 1 hour. Specifically, when the determination to start or stop the set of the heat source unit 3 and the pump 4 is performed a predetermined number of times in the immediate vicinity of controlling the number of operating heat source units 3 and pumps 4, the heat source The operation number of the machine 3 is controlled.

  Below, it demonstrates, referring a table | surface about the result of having simulated the flow control of the cold / hot water by the pump 4 and the control of the operation number of the heat source units 3 by the above-mentioned control method.

First, the case where the measured value of the temperature difference (ΔT) of the cold / hot water acquired from the temperature difference measurement unit 9 and the set temperature difference, which is the temperature difference of the cold / warm water when the heat source system 1 is designed, will be described. .
For example, when the temperature of the cold / hot water is about 5 ° C. and the return temperature is about 15 ° C. when the heat source system 1 is designed, and the set temperature difference is set to about 10 ° C., the temperature difference is measured from the temperature difference measuring unit 9. The case where the temperature difference (ΔT) of the cold / hot water is about 10% of about 100% will be described.

The table shown below shows the actual load (L), the number of proper operation (n), and the flow rate setting value (Fset) for each value of the temperature difference (ΔT) of the cold / hot water acquired from the temperature difference measuring unit 9. It is shown.
In the table, the rated load supplied by one heat source unit 3 or the flow rate of cold / hot water is used as a reference. That is, the flow rate (F) and flow rate set value (Fset) of the cold / hot water in the table are expressed as relative values based on the rated cold / hot water flow rate for one heat source unit 3. On the other hand, the actual load (L) is expressed as a relative value based on the rated load value supplied by one heat source device 3.

  In the above table, when the value of the flow rate (F) of the cold / hot water increases from 0.8 to 1, the value of the actual load (L) increases from 0.8 in proportion to the value of the flow rate (F) of the cold / hot water. Increase to 1. During this time, one heat source unit 3 is in operation. On the other hand, the value of the flow rate setting value (Fset) also increases from 0.8 to 1 in proportion to the value of the flow rate (F) of the cold / hot water.

That is, variable flow control is performed in which the flow rate of the cold / hot water is increased or decreased in accordance with the increase or decrease of the actual load.
The calculation of the flow rate setting value (Fset) and the control of the flow rate (F) of the cold / hot water at this time are performed at intervals of about 1 minute as described above.

  Further, when the value of the flow rate (F) of the cold / hot water increases from 1.2 to 2, the value of the actual load (L) increases from 1.2 to 2 in proportion to the value of the flow rate (F) of the cold / hot water. To do. Then, since the amount of heat that can be supplied by one heat source device 3 is insufficient, one heat source device 3 is newly activated and two heat source devices 3 are operated. On the other hand, the value of the flow rate setting value (Fset) increases from 0.6 to 1 in proportion to the value of the flow rate (F) of the cold / hot water because two pumps 4 are operated.

That is, the number control for controlling the number of the heat source devices 3 to be operated is performed in accordance with the increase or decrease of the actual load.
In addition, the start control of the heat source unit 3 at this time is performed at intervals of about 30 minutes to 1 hour in accordance with the characteristics of the heat source unit 3 as described above.

  Conversely, when the value of the flow rate (F) of the cold / hot water decreases, the actual load (L) and the value of the flow rate setting value (Fset) decrease in proportion to the value of the flow rate (F) of the cold / hot water. On the other hand, the number of operating heat source units 3 is reduced from two to one when the value of the flow rate (F) of cold / hot water decreases from 1.2 to 1.

Next, the case where the measured value of the temperature difference (ΔT) is smaller than the set temperature difference will be described with reference to the following table.
For example, when the temperature of the cold / hot water is about 5 ° C. and the return temperature is about 15 ° C. when the heat source system 1 is designed, and the set temperature difference is set to about 10 ° C., the temperature difference is measured from the temperature difference measuring unit 9. The case where the temperature difference (ΔT) of the cool / warm water is about 8 ° C., which is about 80%, will be described.

  In the above table, when the value of the flow rate (F) of the cold / hot water increases from 0.8 to 1.2, the value of the actual load (L) is proportional to the value of the flow rate (F) of the cold / hot water. Increase from 64 to 0.96. During this time, one heat source unit 3 is in operation. On the other hand, the value of the flow rate set value (Fset) increases from 0.8 to 1.2 in proportion to the value of the flow rate (F) of the cold / hot water.

  As described above, the heat source devices 3 and the pumps 4 are arranged in a one-to-one correspondence and are started and stopped at the same time. Therefore, the values of the flow rate (F) and the flow rate setting value (Fset) of the cold / hot water are 1. .2, the pump 4 is controlled in an overflow state, that is, overflow control is performed. At the same time, an excessive flow of chilled / warm water that is higher than the rated chilled / warm water flow rate is also flowing to the operating heat source unit 3.

  Furthermore, when the value of the flow rate (F) of the cold / hot water increases from 1.4 to 2.4, the value of the actual load (L) increases from 1.12 to 1 in proportion to the value of the flow rate (F) of the cold / hot water. Increase to .92. Then, since the amount of heat that can be supplied by one heat source device 3 is insufficient, one heat source device 3 is newly activated and two heat source devices 3 are operated. On the other hand, the value of the flow rate setting value (Fset) increases from 0.7 to 1.2 in proportion to the value of the flow rate (F) of the cold / hot water because two pumps 4 are operated.

  Furthermore, for example, when the temperature of the cold / hot water is about 5 ° C. and the return temperature is about 15 ° C. when the heat source system 1 is designed, and the set temperature difference is set to about 10 ° C., the temperature difference measuring unit 9 A case where the temperature difference (ΔT) of the acquired cold / hot water is about 6 ° C., which is about 60%, will be described.

  In the above table, when the value of the flow rate (F) of the cold / hot water is increased from 0.8 to 1.6, the value of the actual load (L) is proportional to the value of the flow rate (F) of the cold / hot water. Increase from 48 to 0.96. During this time, one heat source unit 3 is in operation. On the other hand, the value of the flow rate setting value (Fset) increases from 0.8 to 1.6 in proportion to the value of the flow rate (F) of the cold / hot water.

  In addition, when the value of the flow rate (F) and flow rate setting value (Fset) of cold / hot water is 1.2 to 1.6, the pump 4 is controlled in an overflow state. At the same time, an excessive flow of chilled / warm water that is higher than the rated chilled / warm water flow rate is also flowing to the operating heat source unit 3.

  Further, when the value of the flow rate (F) of the cold / hot water increases from 1.8, the value of the actual load (L) increases from 1.08 in proportion to the value of the flow rate (F) of the cold / hot water. Then, since the amount of heat that can be supplied by one heat source device 3 is insufficient, one heat source device 3 is newly activated and two heat source devices 3 are operated. On the other hand, the value of the flow rate setting value (Fset) is 0.9 in proportion to the value of the flow rate (F) of the cold / hot water because two pumps 4 are operated.

  According to said structure, since the flow volume of the cold / hot water sent out by the pump 4 is controlled based on the flow setting value (Fset) calculated | required from the actual load (L) and the temperature difference ((DELTA) T) at least, for example, When the temperature difference (ΔT) becomes smaller than the set temperature difference, the above-described control of increasing the flow rate of the cold / hot water is performed based on the temperature difference (ΔT) in order to satisfy the required actual load (L). Here, in the pump 4, since the maximum delivery flow rate per unit time is an excessive flow rate, the flow rate of the cold / hot water is controlled to the excessive flow rate. Therefore, it is not necessary to excessively increase the number of operating heat source devices 3 with respect to the heat load required from the external load 5, that is, the actual load (L), and increase in power consumption of the heat source system 1 can be prevented.

  On the other hand, since the number of heat source devices 3 and pumps 4 operated based on the actual load (L) is controlled, the number of heat source devices 3 and pumps 4 operated when the actual load (L) increases. When increased and the actual load (L) is decreased, the number of heat source devices 3 and pumps 4 to be operated is decreased. Since the actual load (L) is also a thermal load required from the external load 5, by controlling the number of operating heat source units 3 and pumps 4 in this manner, the number of operating heat source units 3 is not increased excessively. The above-mentioned required heat load can be satisfied.

  Since the heat source unit 3 is started and stopped together with the pump 4 corresponding to the heat source unit 3, the cold / hot water returned from the external load 5 is again heated to the external load 5 without being heated or cooled by the heat source unit 3. Never sent. That is, since the cold / hot water is always heated or cooled by the heat source device 3 and then sent to the external load 5, compared with the case where the pump 4 and the heat source device 3 are started and stopped separately, the external load 5 The temperature of the cold / hot water delivered can be easily controlled.

  Since the flow rate of the cold / hot water sent out by the plurality of pumps 4 is controlled based on the flow rate setting value (Fset) of the cold / warm water obtained in the flow rate calculation unit, the flow rate of the cold / hot water can be reliably controlled.

For fluctuations in the actual load (L) that does not require the number of operating heat source units 3 to be increased or decreased, the flow of cold / hot water can be increased or decreased in proportion to the actual load (L), That is, the thermal load required from the external load 5 can be satisfied.
Therefore, it is not necessary to excessively increase / decrease the number of operating heat source units 3 with respect to fluctuations in the actual load (L), and increase in power consumption of the heat source system 1 can be prevented.

When the temperature difference (ΔT) is smaller than the design temperature difference, the flow rate of the heat medium necessary to satisfy the actual load (L) even if the actual load (L) required by the external load 5 is the same. Will increase. In such a case, it is possible to cope with the increased required flow rate of the heating medium by expanding the upper limit value of the flow rate setting value to a value corresponding to the above-described overflow rate.
Therefore, it is not necessary to excessively increase the number of operating heat source units 3 with respect to the required actual load (L), and increase in power consumption of the heat source system 1 can be prevented.

  The above-described temperature difference (ΔT) is reduced and the flow rate of cold / hot water necessary to satisfy the actual load (L) is increased. When the total value (Fmax) of the upper limit flow rate values is exceeded, a new set of the heat source unit 3 and the pump 4 is started. Therefore, the flow rate of the cold / hot water per set of the heat source device 3 and the pump 4 is reduced, and the flow rate of the cold / hot water in the heat source device 3 is reduced within an appropriate flow rate range. Then, compared with the case where the flow rate of the cold / hot water in the heat source device 3 is not lowered, it is possible to prevent the heat transfer tube through which the cold / hot water flows from being thinned.

On the other hand, when the required cold / hot water flow rate is lower than the total value (Fmin) of the lower limit flow rate values of the operating heat source units 3, the total value (Fmin) of the lower limit flow rate values is set to the flow rate setting value (Fset). ), The flow rate of the cold / hot water in the heat source unit 3 can be ensured, and the freezing of the cold / hot water can be prevented.
In addition, as a lower limit flow value of each heat-source equipment 3, the value of about 50% of a rated flow can be mentioned, for example.

  Control of the flow rate of cold / warm water that can be changed in a short time compared to the start-up of the heat source unit 3 is performed at an interval shorter than the control timing of the number control of the heat source units 3. On the other hand, for the control of the number of operating heat source units 3 that require time-consuming startup of the heat source unit 3 that takes time compared to the control of the flow rate of the cold / hot water, the control is performed at an interval longer than the control timing of the flow rate of the cold / hot water. Is called.

  Therefore, since it is not necessary to start up the heat source device 3 in a short time, an excessive load is not applied to the heat source device 3, and failure of the heat source device 3 can be prevented. Furthermore, by controlling the flow rate of the cold / hot water that is easy to control at short intervals and has a low risk of failure or the like, the short-term fluctuations in the actual load can be followed.

By setting the control timing interval of the number of operating heat source units 3 based on the start-up characteristics of the heat source unit 3, it is not necessary to start up the heat source unit 3 in a short time. Thus, the life of the heat source device 3 can be extended.
For example, when the heat source unit 3 is a turbo refrigerator, the number of operating units is controlled at a shorter interval than in the case of an absorption refrigerator. On the other hand, when the heat source device 3 is an absorption refrigerator, the number of operating units is controlled at a longer interval than in the case of a turbo refrigerator.

  Since the flow rate of the cold / hot water delivered by the pump 4 is controlled based on the flow rate setting value (Fset) obtained by the calculation, for example, when the above-described temperature difference (ΔT) becomes small, the required actual load In order to satisfy (L), control is performed to increase the flow rate of the cold / hot water based on the temperature difference (ΔT).

  On the other hand, since the number of heat source devices 3 and pumps 4 operated based on the actual load (L) is controlled, the number of heat source devices 3 and pumps 4 operated when the actual load (L) increases. When increased and the actual load (L) is decreased, the number of heat source devices 3 and pumps 4 to be operated is decreased.

  Thus, since the control of the flow rate of cold / hot water and the control of the number of operating heat source units 3 and pumps 4 can be performed by a single algorithm without using a complicated switching logic, the required heat load And while satisfy | filling flow volume load, the increase in the motive power which the heat source system 1 consumes can be prevented easily.

  Note that, as in the above-described embodiment, the plurality of heat source units 3 may have substantially the same capability, and the plurality of pumps 4 may have substantially the same capability, or the capabilities of the plurality of heat source units 3 may be different. There is no particular limitation. In such a case, the capacities of the pumps 4 are also selected according to the capacities of the respective heat source devices 3, so that the capacities of the plurality of pumps 4 are also different.

In the case of such a configuration, the flow rate set value (Fset) calculated in the control unit 11 is determined so that the load factor in each of the heat source devices 3 being operated is substantially equal. When the load factor in each heat source device 3 becomes substantially equal, the load factor also becomes substantially equal in the pump 4 installed corresponding to each heat source device 3.
Therefore, the heads (heads) are substantially equal between different sets of the heat source device 3 and the pump 4, and the flow of the cold / hot water sent from each pump 4 is inhibited by the cold / hot water sent from the other pumps 4. Without being sent to the external load 5.

  The plurality of heat source units 3 may be unified with one type of refrigerators such as a turbo refrigerator or an absorption refrigerator, or several types of refrigerators may be mixed and used. There is no particular limitation.

FIG. 5 is a schematic diagram for explaining another embodiment of the heat source system of FIG. 1.
As described above, the heat source system 1 may control the flow rate of cold / hot water flowing through the external load 5 by combining the flow control valve 6 that is a two-way valve with the external load 5, as shown in FIG. As shown, the flow rate control valve 6A, which is a three-way valve, may be combined with the external load 5 to control the flow rate of cold / hot water flowing through the external load 5, and is not particularly limited.
The flow rate control valve 6 </ b> A is a combined three-way valve in which cold / hot water flowing out from the external load 5 and cold / warm water bypassing the external load 5 flow toward the heat source unit 3.

  In such a configuration, the amount of heat exchange in the external load 5 is controlled by controlling the ratio of the cold / hot water flowing through the external load 5 and the cold / hot water bypassing the external load 5 using the flow control valve 6A. . Then, the temperature difference (ΔT) between the feed temperature and the return temperature of the cold / hot water greatly varies depending on the magnitude of the heat load in the external load 5.

FIG. 6 is a schematic diagram illustrating still another embodiment of the heat source system of FIG.
As described above, as the heat source system 1, cold / hot water may be circulated only by the pump 4 that is an inverter pump, or the secondary pump 4 </ b> A is connected to the heat source unit 3 and the external load 5 as shown in FIG. 6. The cold / hot water may be circulated using the pump 4 and the secondary pump 4A, and is not particularly limited.

  The secondary pump 4A is an inverter pump, for example, and a plurality of secondary pumps 4A are arranged in parallel. A control signal is input to the secondary pump 4A from the secondary pump control unit 11A. The measured value of the pressure difference measuring unit 12 that measures the pressure difference between the inflow side and the outflow side of the external load 5 is input to the secondary pump control unit 11A. A control signal for the secondary pump 4A is output based on the measured value.

  By setting it as such a structure, even if the external load 5 is installed in the high-rise floor of a high-rise building, for example, sufficient head which sends cold / hot water to the said external load 5 is securable. That is, when the flow rate of the cold / hot water flowing through the external load 5 increases and the pressure difference measured by the pressure difference measuring unit 12 decreases, the secondary pump control unit 11A outputs a control signal for starting the secondary pump 4A. And the flow volume of the cold / hot water supplied to the external load 5 is securable by operating the secondary pump 4A.

FIG. 7 is a schematic diagram illustrating still another embodiment of the heat source system of FIG.
As described above, the cold / hot water may be sent from the heat source unit 3 to the external load 5 using the pump 4 and the secondary pump 4A which are inverter pumps, or fixed instead of the pump 4 as shown in FIG. The hot / cold water may be sent from the heat source unit 3 to the external load 5 using the fixed pump 4B and the fixed pump 4B and the secondary pump 4A using the fixed pump 4B, which is not particularly limited. However, in this case, the output destination of the flow rate set value is the flow rate control valve 4C.
In the case of the configuration shown in FIG. 7, a decoupler 13 that is a flow path connecting between the heat source device 3 and the secondary pump 4 </ b> A and between the flow rate measuring unit 7 and the fixed pump 4 </ b> B is provided.

  By adopting such a configuration, when the flow rate of cold / hot water sent from the fixed pump 4B is larger than the flow rate of cold / warm water required by the external load 5, the flow is sent from the fixed pump 4B via the heat source unit 3. A part of the cool / warm water passes through the decoupler 13 and is led to the inflow side of the fixed pump 4B, and the difference in flow rate is absorbed. On the contrary, when the flow rate of the cold / hot water sent from the fixed pump 4B is smaller than the flow rate of the cold / warm water required by the external load 5, a part of the cold / warm water flowing from the external load 5 to the fixed pump 4B is decoupled. Is passed to the secondary pump 4A and the difference in flow rate is absorbed.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the flow rate of the cold / warm water delivered from the pump is described as applied to a method of controlling based on the temperature difference between the feed temperature of the heat medium and the return temperature of the heat medium. However, the control method is not limited to the above-described control method based on the temperature difference, and the control method is based on the amount of heat related to the heat medium measured by the calorimeter, and the actual load applied to each device on the load side is totaled and controlled. Other control methods such as a method may be used and are not particularly limited.

It is a mimetic diagram explaining the composition of the heat source system concerning one embodiment of the present invention. It is a flowchart explaining control of the pump and heat source machine in the heat source system of FIG. It is a flowchart explaining control of the pump and heat source machine in the heat source system of FIG. It is a flowchart explaining control of the pump and heat source machine in the heat source system of FIG. It is a schematic diagram explaining another embodiment of the heat-source system of FIG. It is a schematic diagram explaining another embodiment of the heat-source system of FIG. It is a schematic diagram explaining another embodiment of the heat-source system of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat source system 3 Heat source machine 4 Pump 5 External load 7 Flow rate measurement part 9 Temperature difference measurement part 11 Control part (flow rate control part, number control part)

Claims (10)

A plurality of heat source machines for cooling or heating the heat medium flowing in from an external load;
A plurality of pumps arranged corresponding to each of the plurality of heat source units and started and stopped together with the corresponding heat source units, and sending the cooled or heated heat medium to the external load;
A load calculator that calculates and calculates the actual load on the heat source system;
Based on at least the actual load, a flow rate control unit that controls the flow rate of the heat medium sent out by the plurality of pumps;
A unit control unit for controlling the number of operating heat source units and pumps based on the actual load;
Is provided,
The flow rate control device for a heat source system, wherein a maximum delivery flow rate per unit time in at least one of the pumps is an excessive flow rate that is larger than a delivery flow rate of the heat medium at the time of maximum heat load. A flow rate measuring unit for measuring the flow rate of the heat medium flowing through the external load;
A temperature difference measuring unit for measuring a temperature difference between a feed temperature of the heating medium sent to the external load and a return temperature of the heating medium returning from the external load to the heat source unit;
Is provided,
The load calculation unit calculates the actual load from the measurement values obtained by the flow rate measurement unit and the temperature difference measurement unit,
2. The flow rate control device for a heat source system according to claim 1, wherein the flow rate control unit controls a flow rate of the heat medium sent out by the plurality of pumps based on at least the actual load and the temperature difference. Based on the temperature difference measured by the temperature difference measuring unit, a flow rate set value that is a set value of the flow rate of the heat medium sent out by the plurality of pumps is obtained, and the flow rate set value is output to the flow rate control unit. A flow rate calculation unit is provided,
The flow rate control device for a heat source system according to claim 2, wherein the flow rate control unit controls the flow rate of the heat medium based on the input flow rate setting value.   4. The flow rate control device for a heat source system according to claim 3, wherein the flow rate calculation unit causes the magnitude of the flow rate setting value to be proportional to the actual load.   The flow rate calculation unit sets the upper limit value of the flow rate setting value when an operating temperature difference that is a temperature difference of the heat medium at the time of operation is smaller than a set temperature difference that is a temperature difference of the heat medium at the time of design. The flow rate control device for a heat source system according to claim 2, wherein the flow rate control device is expanded to a value corresponding to the excess flow rate. When there are a plurality of sets of the heat source machine and the pump being operated,
6. The flow rate calculation unit obtains the flow rate setting value at which a load factor is substantially equal among a plurality of sets of the operated heat source machines and pumps, according to claim 3. Flow control device for heat source system.   The number control unit is stopped when the flow rate of the heating medium obtained based on the actual load and the temperature difference exceeds the total of the upper limit flow rate values of the heat source machine being operated. The flow control device for a heat source system according to any one of claims 2 to 7, wherein a set of a heat source machine and a pump is newly activated.   8. The interval of the control timing of the flow rate of the heat medium by the flow rate control unit is shorter than the control timing interval of the number of operating heat source units by the unit control unit. The flow control device of the described heat source system.   The flow rate control device for a heat source system according to claim 8, wherein an interval of control timing of the number of operating heat source units by the flow rate control unit is set based on a start characteristic of the heat source unit. While measuring the flow rate of the heat medium sent from the plurality of heat source devices to the external load, the feed temperature of the heat medium sent to the external load, and the return temperature of the heat medium returning from the external load to the heat source device A measurement step for measuring the temperature difference between and
An actual load calculating step of calculating an actual load based on the temperature difference and the flow rate of the heating medium;
A unit number calculating step for calculating the number of operating heat source units required to supply the heat medium according to the actual load;
A set flow rate calculation step for calculating a flow rate set value necessary for supplying the heat medium according to the actual load;
When the number of operating heat source units obtained by calculation is larger than the number of operating heat source units being operated, the number of operating heat source units is increased, and the operation of the heat source unit being operated is increased. An operation number control step for reducing the number of operating heat source devices in operation when the number is less than the number;
Based on the flow rate setting value obtained by calculation, a flow rate control step for controlling the flow rate of the heat medium sent from the plurality of heat source units to the external load;
A flow rate control method for a heat source system.

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