JP2012189262A - Heat source system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat source system which is more excellent in energy saving and reduction in operation cost.SOLUTION: In the operation of jointly using primary and secondary pumps, the reflux amount of heat medium C from the secondary side outward header H2 to the primary side outward header H1 through a pump bypass path 5 is adjusted by adjusting the opening of a pump bypass valve 5v, thereby, a heat medium supply pressure pm for load equipment U is adjusted to a set supply pressure. In the operation of singly using the primary pump, the pump bypass valve 5v is opened to the full to feed the supply heat medium C by means of the primary pump P1 from the primary side outward header H1 to the secondary side header H2 through the pump bypass path 5.

Description

  The present invention relates to a heat source system used for air conditioning equipment and the like.

  For details (see FIG. 1), a load device U is interposed in the secondary flow path 2 that connects the secondary outgoing header H2 and the return header RH, and the return header RH and the primary outgoing header H1 are connected. A primary pump P1 that sends a heat medium C toward the primary side forward header H1 and a heat source unit 3 that cools or heats the heat medium C are interposed in series in the primary flow path 1 to be connected, A system configuration in which a secondary pump P2 for sending a heating medium C toward the secondary forward header H2 is interposed in the relay path 4 connecting the primary forward header H1 and the secondary forward header H2. To do.

  In this configuration, the primary / secondary pump combined operation for circulating the heat medium C between the heat source device 3 and the load device U by the operation of the primary pump P1 and the secondary pump P2, and A configuration in which the primary pump single operation in which the heat medium C is circulated between the heat source device 3 and the load device U is selectively performed by stopping the secondary pump P2 and operating the primary pump P1. Related heat source system.

  This kind of heat source system is selectively operated by primary / secondary pump combined operation and primary pump single operation, compared to a heat source system that always performs primary / secondary pump combined operation. The power required for the operation of the next pump is reduced to enable energy saving and operation cost reduction. Conventionally, this type of heat source system is disclosed in Patent Document 1.

JP 2001-241735 (particularly FIG. 1)

  However, in the conventional system shown in Patent Document 1, in the single pump single operation where the secondary pump is stopped and the heat medium is circulated between the heat source device and the load device by the operation of the primary pump, the primary pump is used. Thus, the heat medium supplied to the primary forward header (that is, the heat medium cooled or heated by the heat source device) is sent to the load device through the secondary pump in a stopped state.

  For this reason, in the primary pump single operation, the secondary pump that is in a stopped state becomes a large heat medium passage resistance (in other words, a large pressure loss factor), which increases the power required for the operation of the primary pump. There is a problem that energy saving and reduction of operation cost are limited.

  In addition, since the stopped secondary pump has a large resistance to passing through the heat medium, the supply of the heat medium to the load equipment becomes unstable in the single pump single operation, which makes the operation of the load equipment unstable. There was also a risk of becoming.

  In view of this situation, the main problem of the present invention is to effectively solve the above problems by rational improvements.

The first characteristic configuration of the present invention relates to a heat source system, and the characteristic is as follows:
Load equipment is installed in the secondary side flow path connecting the secondary side forward header and return header,
A primary pump that sends a heat medium toward the primary-side forward header and a heat source device that cools or heats the heat medium are connected in series to a primary-side flow path that connects the return header and the primary-side forward header. Intervening in,
A relay path connecting the primary side forward header and the secondary side forward header is provided with a secondary pump that sends a heat medium toward the secondary forward header,
Depending on the switching command or the load heat amount of the load device or the heat medium flow rate in the load device, the heat medium is transferred between the heat source device and the load device by the operation of the primary pump and the secondary pump. Primary and secondary pump combined operation for circulation, and primary pump single operation for stopping the secondary pump and circulating the heat medium between the heat source device and the load device by the operation of the primary pump, A heat source system provided with control means for selectively performing
While providing a pump bypass path connecting the primary side forward header and the secondary forward header, a pump bypass valve is interposed in the pump bypass path,
In the combined operation of the primary and secondary pumps, the control means adjusts the opening degree of the pump bypass valve and heat medium from the secondary side forward header to the primary side forward header through the pump bypass path. By adjusting the recirculation amount, the heat medium supply pressure for the load device is adjusted to the set supply pressure,
In the primary pump single operation, the pump bypass valve is fully opened, and the supply heat medium supplied by the primary pump is sent from the primary side forward header to the secondary side header through the pump bypass path. It is in.

  In other words, according to this configuration (see FIG. 1), in the combined operation of the primary and secondary pumps, the heat medium C is cooled or heated by the heat source unit 3 to circulate the heat medium C between the heat source unit 3 and the load device U. The heating medium C is supplied to the primary side forward header H1 by the primary pump P1, and then the heating medium C is sent to the load device U through the secondary side forward header H2 by the secondary pump P2. A circulation mode is adopted in which the heat medium C delivered from U (that is, the heat medium C in which the retained cold heat or the retained heat is consumed by the load device U) is returned to the heat source unit # through the return header RH.

  In this primary / secondary pump combined operation, the opening degree of the pump bypass valve 5v interposed in the pump bypass path 5 connecting the primary side forward header H1 and the secondary side forward header H2 is adjusted to pump Heat medium supply pressure to the load device U by adjusting the amount of reflux of the heat medium C (indicated by the solid arrow in the figure) from the secondary side forward header H2 to the primary side forward header H1 through the bypass 5 Adjust pm to the set supply pressure. That is, by adjusting the heating medium supply pressure pm, the heating medium C can be stably supplied to the load device U in a good state without excess or deficiency.

  On the other hand, in the primary pump single operation, in order to circulate the heat medium C between the heat source device 3 and the load device U, the heat medium cooled or heated by the heat source device 3 by fully opening the pump bypass valve 5v. C is supplied to the primary side forward header H1 by the primary pump P1, and subsequently, the heating medium C is similarly supplied from the primary side forward header H1 through the pump bypass passage 5 by the supply pressure of the primary pump P1. It is sent to the secondary side forward header H2 (indicated by a broken arrow in the figure) and sent from the secondary side forward header H2 to the load device U, and accordingly, the heat medium C sent from the load device U is returned to the return header RH. The circulation form which returns to the heat source machine 3 through is taken.

  That is, in the primary pump single operation, the pump bypass valve 5v is fully opened, so that the heat medium C is transferred from the secondary forward header H2 to the primary forward header H1 in the primary / secondary pump combined operation. Using the pump bypass passage 5 used for the reflux, the heat medium C supplied by the primary pump P1 is bypassed from the primary side forward header H1 to the stopped secondary pump through the pump bypass passage 5 with respect to P2. In the state, it is sent to the secondary outbound header H2.

  Accordingly, in the primary pump single operation, the secondary pump P2 in the stopped state is compared with the above-described conventional system in which the heating medium C is sent from the primary side forward header H1 to the secondary side forward header H2 through the secondary pump P2 in the stopped state. As a result, it is possible to reduce the resistance to passage of the heat medium during the primary pump single operation, thereby effectively reducing the power required for the operation of the primary pump P1, thereby reducing energy consumption and operating costs. Reduction can be achieved more effectively, and the supply of the heat medium to the load device U during the primary pump single operation can be further stabilized.

  In the primary pump single operation, since the heat medium is circulated between the heat source unit and the load device only by the primary pump operation, the heat medium supply pressure to the load device in the primary pump single operation is performed. This adjustment may be performed by adjusting the rotational speed of the primary pump P1, as will be described later.

  Further, as the heat medium supply pressure for the load equipment, it is preferable to adopt the heat medium supply pressure for the end load equipment (so-called end pressure) having the longest pipe length from the secondary side forward header, but it is not limited to this. Instead, it may be a heat medium pressure in the middle of the forward path portion of the secondary side flow path connecting the secondary side forward header and the load device, or a heat medium pressure in the secondary side forward header.

  Furthermore, the set supply pressure may be set by calculating the pressure that can supply the heat medium to the load equipment without excess or deficiency based on the pump performance, piping resistance, etc. The set supply pressure may be set based on the calculated value of the pressure difference.

The second feature configuration of the present invention is a configuration suitable for the implementation of the first feature configuration.
While providing an inter-header bypass path connecting the primary side header and the return header, inter-header bypass valve is interposed in the inter-header bypass path,
The control means adjusts the opening degree of the inter-header bypass valve at the time of transition from the primary / secondary pump combined operation to the primary pump single operation, thereby adjusting the heat medium supply pressure to the load device. The configuration is such that the set supply pressure is adjusted.

  That is, (see FIG. 1), the inter-header bypass path 6 that connects the primary side forward header H1 and the return header RH generally has the heat medium flow rate of the primary side path 1 in the combined operation of the primary and secondary pumps. A difference between the flow rate of the heat medium in the secondary side flow path 2 is provided to absorb the flow rate difference by short-circuit heat medium circulation through the inter-header bypass path 6. When the intermediate bypass path 6 is provided, when the transition from the primary / secondary pump combined operation to the primary pump single operation is entered while the free passage of the heat medium to the inter-header bypass path 6 is possible, the primary side Most of the heat medium C supplied to the forward header H1 is in a state where it flows into the inter-header bypass path 6 from the primary side forward header H1 due to the supply pressure of the primary pump P1 for the stop operation of the secondary pump P2. Therefore, the heat medium C is applied to the load device U. It leads to sincerely not supplied situation.

  In addition, during the transition from primary / secondary pump combined operation to primary pump single operation, the secondary pump is stopped so that the load is adjusted by adjusting the rotational speed of the secondary pump P2 and adjusting the opening of the pump bypass valve 5v. The heat medium supply pressure pm for the device U cannot be adjusted.

  On the other hand, in the above configuration, the opening degree of the inter-header bypass valve 6v is adjusted by using the inter-header bypass valve 6v when the primary / secondary pump combined operation is shifted to the primary pump single operation. By doing this, the heat medium supply pressure pm for the load device U is adjusted to the set supply pressure in a form in which the heat medium passage resistance is given to the inter-header bypass path 6.

  That is, this prevents most of the heating medium C supplied to the primary side forward header H1 from flowing into the inter-header bypass path 6 from the primary side forward header H1, and stable heat for the load device U. It is possible to shift to the primary pump single operation while keeping the medium supply.

The third feature configuration of the present invention is a configuration suitable for implementation to the second feature configuration.
The control means gradually decreases the rotation speed of the secondary pump as the rotation speed of the primary pump is gradually increased when the primary / secondary pump combined operation is shifted to the primary pump single operation. Thus, the secondary pump is stopped.

  In other words, according to this configuration (see FIG. 1), the secondary pump P2 that is operating at the required rotational speed in the combined operation of the primary and secondary pumps is suddenly stopped along with the shift to the primary pump single operation. Or, when the primary / secondary pump combined operation is shifted to the primary pump single-use operation, the rotational speed of the primary pump P1 is rapidly increased to cover the stop of the secondary pump P2. As compared with the above, it is possible to shift from the primary / secondary pump combined operation to the primary pump single operation while maintaining stable supply of the heat medium to the load device U.

  In addition, it is possible to effectively prevent the primary pump P1 and the secondary pump P2 from being deteriorated or damaged due to a rapid change in the rotational speed.

The fourth feature configuration of the present invention is a configuration suitable for implementing the second or third feature configuration.
In the primary pump single operation, the control means adjusts the rotation speed of the primary pump in a state where the opening degree of the inter-header bypass valve is limited or in a state where the inter-header bypass valve is closed, The heat medium supply pressure for the load device is adjusted to the set supply pressure.

  That is, (see FIG. 1), when the primary pump single-use operation is performed while allowing free passage of the heat medium to the inter-header bypass path 6, the heat supplied to the primary forward header H1 is the same as described above. Since most of the medium C stops the secondary pump P2, the supply pressure of the primary pump P1 causes the primary pump P1 to flow into the inter-header bypass path 6 from the primary side forward header H1.

  On the other hand, in the above configuration, the opening degree of the inter-header bypass valve 6v is limited or the inter-header bypass valve 6v is closed in the primary pump single-use operation, thereby being supplied to the primary forward header H1. Most of the heat medium C is prevented from flowing into the inter-header bypass path 6 from the primary side forward header H1.

  The heating medium supply pressure pm to the load device U is adjusted by adjusting the rotation speed of the primary pump P1 in a state where the opening degree of the inter-header bypass valve 6v is limited or the inter-header bypass valve 6v is closed. Adjust to the set supply pressure.

  That is, by these things, the heating medium C can be stably supplied to the load device U in a good state without excess or deficiency even in the primary pump single operation.

  In the primary pump single operation, when the heating medium supply pressure pm for the load device U is directly adjusted to the set supply pressure by adjusting the opening of the inter-header bypass valve 6v as described above, The flow rate of the heat medium C flowing into the inter-header bypass path 6 from the primary forward header H1 can be reduced as compared with the case where the passage of the heat medium with respect to the inter-path bypass path 6 is made free. The flow rate of the short-circuit heat medium circulation (that is, the waste heat medium circulation that causes waste of the primary pump power) toward the return header RH through the path 6 is increased in the primary pump single operation.

  In this regard, according to the above configuration, the opening degree of the inter-header bypass valve 6v is fixedly limited or the inter-header bypass valve 6v is closed, so that the above-described useless heat medium circulation through the inter-header bypass path 6 is effective. Therefore, the power required for the operation of the primary pump P1 can be further effectively reduced.

The fifth characteristic configuration of the present invention is a configuration suitable for implementing any one of the second to fourth characteristic configurations,
In the combined operation of the primary and secondary pumps, the control means adjusts the opening degree of the inter-header bypass valve so as to change the pressure difference state between the primary side forward header and the return header. The heat medium pressure in the next forward header is adjusted to be higher than the heat medium pressure in the return header by a set pressure difference.

  In other words, according to this configuration (refer to FIG. 1), among the short-circuit heat medium circulation through the inter-header bypass path 6 that can occur in the combined operation of the primary and secondary pumps, a load that becomes wasteful heat medium circulation The heat medium C that has once passed through the load device U is allowed to pass through the load device U while allowing short-circuit heat medium circulation through the inter-header bypass path 6 toward the return header RH that does not particularly hinder the operation of the device U. Short-circuit through the inter-header bypass path 6 toward the primary forward header H1 that is in a state of being supplied to the load apparatus U again through the inter-path bypass path 6 and interferes with the operation of the load apparatus U. Heat medium circulation can be prevented.

  That is, by using the inter-header bypass valve 6v used for adjusting the heat medium supply pressure pm to the load device U during the transition from the combined primary / secondary pump operation to the primary pump single operation, -The operation of the load device U in the secondary pump combined operation can be made better and more stable.

The sixth characteristic configuration of the present invention is a configuration suitable for implementation of any one of the second to fifth characteristic configurations,
The control means starts the secondary pump when the primary pump single-use operation shifts to the primary / secondary pump combined operation, and gradually increases the rotational speed of the secondary pump following the start-up. It is in the point which is made into a structure.

  In other words (see FIG. 1), when the primary pump single operation shifts to the primary / secondary pump combined operation, the secondary pump P2 that has been stopped until then is started. At this time, the secondary pump P2 Compared to a sudden increase in the rotational speed of the primary pump, according to the above configuration, the primary pump is used in a state in which a stable supply of heat medium to the load device U is maintained by gradually increasing the rotational speed of the activated secondary pump P2. It is possible to shift from operation to primary / secondary pump combined operation.

  Further, it is possible to effectively prevent deterioration and damage of the secondary pump P2 caused by a rapid change in the rotational speed.

The seventh characteristic configuration of the present invention is a configuration suitable for the implementation of the sixth characteristic configuration.
When the heating medium supply pressure to the load device rises to a set supply pressure due to a gradual increase in the rotation speed of the secondary pump, the control means determines a pressure difference state between the primary forward header and the return header. The heat medium pressure in the primary side forward header is controlled so as to be adjusted to a state in which it is higher than the heat medium pressure in the return header by a set pressure difference.

  In other words (see FIG. 1), before the heating medium supply pressure pm to the load device U reaches the set supply pressure due to the gradual increase in the rotation speed of the secondary pump P2, the primary side is adjusted by adjusting the opening degree of the inter-header bypass valve 6v. When the control for adjusting the heat medium pressure ps in the forward header H1 to be higher by the set pressure difference Δps than the heat medium pressure pr in the return header RH is started (so-called differential pressure control between headers), it is supplied by the primary pump P1. As the heating medium C flows from the primary side forward header H1 into the inter-header bypass path 6, the secondary pump rotational speed required to increase the heating medium supply pressure pm to the set supply pressure is gradually increased. At the same time, the time required to raise the heating medium supply pressure pm to the set supply pressure becomes longer.

  On the other hand, according to the above configuration, since the heating medium supply pressure ps for the load device U is increased to the set supply pressure by gradually increasing the rotational speed of the secondary pump P2, the inter-header differential pressure control is started. As described above, an increase in the gradual amplification of the secondary pump rotation speed and an increase in the required time can be prevented, and in this respect, energy saving and a reduction in operating cost can be achieved more effectively.

The eighth characteristic configuration of the present invention is a configuration suitable for implementing any one of the first to seventh characteristic configurations,
When the load heat amount of the load device is reduced to a set threshold heat amount or when the heat medium flow rate in the load device is reduced to a set threshold flow rate, the control means starts from the primary / secondary pump combined operation to the primary pump. The point is that the shift to single-use operation is automatically executed.

  In other words, according to this configuration, by setting an appropriate load heat amount value as the set threshold heat amount, when the load heat amount of the load device decreases to the set threshold heat amount, the control unit uses the primary and secondary pumps together. The transition from operation to primary pump single operation is automatically executed.

  Alternatively, by setting an appropriate heat medium flow rate value as the set threshold flow rate, the control means can start from the combined operation of the primary and secondary pumps when the heat medium flow rate in the load device decreases to the set threshold flow rate. The transition to single pump single operation is automatically executed.

  That is, according to the above configuration, the transition from the primary / secondary pump combined operation to the primary pump single operation can be automatically performed at an appropriate timing always with respect to the change of the load heat amount and the load flow rate.

The ninth characteristic configuration of the present invention is a configuration suitable for implementing any one of the first to eighth characteristic configurations,
When the load heat amount of the load device has increased to a set threshold heat amount, or when the heat medium flow rate in the load device has increased to a set threshold flow rate, the control means starts the primary pump single operation from the primary pump single operation. The configuration is such that the transition to the secondary pump combined operation is automatically executed.

  That is, according to this configuration, as described above, by setting an appropriate load heat amount value as the set threshold heat amount, the control means can perform the primary operation when the load heat amount of the load device increases to the set threshold heat amount. The transition from single pump operation to primary / secondary pump combined operation is automatically executed.

  Alternatively, by setting an appropriate load flow rate value as the set threshold flow rate, the control means can change the primary pump single operation from the primary pump single operation when the heat medium flow rate in the load device increases to the set threshold flow rate. The transition to the next pump combined operation is automatically executed.

  That is, according to the above configuration, the transition from the primary pump single operation to the primary / secondary pump combined operation can be automatically performed at an appropriate timing with respect to changes in the load heat amount and the load flow rate.

  When the eighth feature configuration and the ninth feature configuration are implemented in parallel, the transition from primary / secondary pump combined operation to primary pump single operation and primary pump single operation to primary / secondary pump combined use In order to prevent the transition (return) to the operation from being repeated in a hunting manner, the set threshold heat amount or the set threshold flow rate used for the transition from the primary / secondary pump combined operation to the primary pump single operation is 1 It is desirable to set a value that is somewhat smaller than the set threshold heat amount or the set threshold flow rate used for the transition (return) from the single pump single operation to the primary / secondary pump combined operation.

Circuit diagram of heat source system Control flow chart of primary and secondary pump combined operation Control flow chart of primary pump single operation Control flow chart when shifting to primary pump single operation Control flow chart for transition (return) to primary / secondary pump combined operation

  FIG. 1 shows a heat source system, in which a plurality of load devices U such as air conditioners are arranged in parallel in a secondary flow path 2 connecting a secondary outgoing header H2 and a return header HR. A primary pump P1 that sends cold water C as a heat medium toward the primary side forward header H1 to each of a plurality of parallel primary side flow paths 1 that connect the primary side forward header H1 and a heat source machine The refrigerator 3 is interposed in series.

  Each refrigerator 3 is a variable refrigerator that can adjust the cooling capacity by frequency control by the inverter inv, and each primary pump P1 is also controlled by the inverter inv according to the cooling capacity adjustment of the corresponding refrigerator 3. A variable pump that adjusts the rotation speed (that is, adjusts the water supply capacity) is adopted.

  Each of the plurality of parallel relay paths 4 that connect the primary side forward header H1 and the secondary side forward header H2 is provided with a secondary pump P2 that sends chilled water C toward the secondary side forward header H2. Also, a pump bypass valve 5v (in this example, a butterfly valve is used) is connected to the pump bypass path 5 that connects the primary side forward header H1 and the secondary side forward header H2 in parallel with the relay path 4. It is intervening.

  Each of the secondary pumps P2 employs a variable pump that adjusts the rotational speed by frequency control by the inverter inv. Instead of this, at least one secondary pump P2 is made a variable pump and other secondary pumps are used. The pump P2 may be a pump whose rotational speed is fixed.

  The primary side forward header H1 and the return header RH are connected by an inter-header bypass path 6 that short-circuits both the primary side flow path 1 and the secondary side flow path 2 and this inter-header bypass. The path 6 is provided with a header bypass valve 6v (in this example, a butterfly valve is used).

  Each load device U consumes the amount of heat stored in the chilled water C supplied from the refrigerator 3 through the secondary side forward header H2 for a required purpose such as cooling, but each load device U has an individual load heat amount g (that is, The individual chilled water flow rate q is adjusted by the flow rate adjusting valve uv in accordance with the change in the individual required chilled heat amount.

  Si is a temperature sensor that measures the temperature ti (cold water supply temperature) of the chilled water C supplied to the load device U, and So is a temperature to (cold water return temperature) after the return chilled water C sent from the load device U is merged. F is a flow rate sensor that measures the chilled water flow rate Q (= Σq, so-called secondary flow rate) of all load devices U.

  Further, Spm is a pressure sensor that measures the cold water supply pressure pm (so-called end pressure) for the end load device U having the longest pipe length from the secondary forward header H2 as the supply pressure of the cold water C to the load device U, Sdp is a differential pressure sensor that measures a differential pressure Δp between the cold water pressure ps on the primary side forward header H1 side and the cold water pressure pr on the return header RH side with the inter-header bypass valve 6v as a boundary.

  7 is a control device that executes system operation control based on the measurement information of these sensors. This control device 7 basically corresponds to the change in the load heat amount G (= Σg) of all the load devices U, The primary / secondary pump combined operation and the primary pump single operation are selectively performed.

  Specifically, the control device 7 calculates the equation G based on the cold water supply temperature ti measured by the temperature sensors Si and So, the cold water return temperature to, and the secondary cold water flow rate Q measured by the flow sensor F. = Load heat amount G (that is, total required cooling amount) at each time point is sequentially calculated in a calculation form according to = Q × (to-ti).

  When the calculated load heat amount G is greater than the set threshold heat amount Gs (G> Gs), the control device 7 loads the cooling water C by the refrigerator 3 by operating both the primary pump P1 and the secondary pump P2. The primary / secondary pump combined operation that circulates and supplies the equipment U is performed.

  On the other hand, the control device 7 stops the operation of the secondary pump P2 when the calculated load heat amount G is equal to or less than the set threshold heat amount Gs (G ≦ Gs), and supplies the cooling cold water C from the refrigerator 3 to the primary pump P1. The primary pump single-use operation that circulates and supplies the load to the load device U is performed only by the operation.

  As the set threshold heat amount Gs, the number of operating refrigerators 3 is reduced to 1, and the cooling capacity of the last operating refrigerator 3 is reduced to the lower limit (for example, 50% capacity) of the adjustment range by the inverter inv. A load heat amount corresponding to the cooling capacity when the throttle is performed (in other words, the minimum cooling capacity that can be adjusted as a group of three refrigerators) is set.

  That is, when the calculated load heat amount G is larger than the minimum cooling capacity (= Gs) that can be adjusted as the group of refrigerators 3, the control device 7 performs the primary / secondary pump combined operation, and the calculated load heat amount G is reduced to the refrigerator. When the cooling capacity is reduced to a level that is not more than the minimum cooling capacity (= Gs) that can be adjusted as the third group, the primary pump single operation is performed under the operation of the last one refrigerator 3.

  When the primary and secondary pump combined operation and the primary pump single operation are described in further detail, the control device 7 executes the following controls (a) to (d) in the combined operation of the primary and secondary pumps. To do. (See Figure 2)

<Combined operation of primary and secondary pumps>
(A) The operation of the refrigerator 3 according to the change of the calculated load heat quantity G so that the total cooling capacity of the refrigerator 3 that is controlled by the refrigerator 3 and the primary pump P1 becomes a capacity that matches the calculated load heat quantity G. While changing the number, the cooling capacity of the refrigerator 3 to be operated is adjusted by the inverter inv.

  The primary pump P1 starts and stops according to the start and stop of the corresponding refrigerator 3, and adjusts the rotation speed by the inverter inv according to the cooling capacity adjustment of the corresponding refrigerator 3.

(B) Control of the secondary pump P2 The measured chilled water flow rate Q by the flow sensor F is adjusted so that the overall water supply capability of the secondary pump P2 (ie, the secondary side water supply capability) matches the chilled water flow rate Q of the load device U. Accordingly, the number of operating secondary pumps P2 is changed, and the rotational speed of the operating secondary pumps P2 is adjusted by the inverter inv.

(C) Control of pump bypass valve 5v (supply pressure control by pump bypass valve 5v)
Based on the chilled water supply pressure pm measured by the pressure sensor Spm, the opening degree of the pump bypass valve 5v is adjusted, and the chilled water C from the secondary side forward header H2 to the primary side forward header H1 through the pump bypass path 5 (FIG. 1). The chilled water supply pressure pm (terminal pressure) with respect to the end load device U is adjusted to the set supply pressure pms by adjusting the amount of recirculation (indicated by the solid line arrow).

(D) Control of the header bypass valve 6v (header differential pressure control)
Based on the measured differential pressure Δp (= ps−pr) measured by the differential pressure sensor Sdp, the pressure difference state between the primary forward header H1 and the return header RH is adjusted by adjusting the opening of the inter-header bypass valve 6v. The chilled water pressure ps in the primary outgoing header H1 is adjusted to be higher than the chilled water pressure pr in the return header RH by a set pressure difference Δps.

  Further, the control device 7 executes the following controls (e) to (g) under the state where all the secondary pumps P2 are stopped in the primary pump single operation. (See Figure 3)

<Single pump single operation>
(E) Control of refrigerator 3 Only one refrigerator 3 is operated in a state where the capacity is fixed to the lower limit cooling capacity (corresponding to the above-described set threshold heat amount Gs) of the capacity adjustment range by the inverter inv.

  Further, all the secondary pumps P2 are kept in a stopped state, and only one primary pump P1 corresponding to the operating refrigerator 3 is operated.

(F) Control of each valve 5v, 6v The opening of the inter-header bypass valve 6v is fixedly limited to the required throttle opening, and in that state, the pump bypass valve 5v is kept fully open, Cooling water C from the refrigerator 3 supplied by the primary pump P1 is sent from the primary side forward header H1 to the secondary side forward header H2 through the pump bypass 5 and supplied to the load device U (in FIG. 1) (Shown by dashed arrows).

(G) Control of the primary pump P1 (supply pressure control by the primary pump P1)
Based on the measured cold water supply pressure pm by the pressure sensor Spm, the number of revolutions of the primary pump P1 is adjusted by the inverter inv, thereby adjusting the cold water supply pressure pm (terminal pressure) for the end load device U to the set supply pressure pms.

  Next, the operation transition between the primary / secondary pump combined operation and the primary pump single operation will be described. The control device 7 starts from the primary / secondary pump combined operation to the primary pump single operation. The transition to operation is performed according to the following procedures (H) to (L). (See Figure 4)

<Transition from primary / secondary pump combined operation to primary pump single operation>
(H) When the calculated load heat amount G decreases to a set threshold heat amount Gs or less (G ≦ Gs), the rotational speed of the secondary pump P2 is gradually decreased by the inverter inv from the state at that time, and the rotational speed of the primary pump P1 is decreased. It is gradually increased by the inverter inv.

  (I) Further, in the process of gradually decreasing and gradually increasing the pump rotation speed, the chilled water supply pressure to the terminal load device U is adjusted by adjusting the opening degree of the header bypass valve 6v based on the measured chilled water supply pressure pm by the pressure sensor Spm. pm (terminal pressure) is adjusted to the set supply pressure pms (supply pressure control by the inter-header bypass valve 6v).

  (N) When the rotation speed of the secondary pump P2 is reduced to the lower limit of adjustment by the inverter inv (for example, 20% rotation speed), the secondary pump P2 is stopped and the pump bypass valve 5v is fully opened, whereby the primary pump The cooling chilled water C from the refrigerator 3 supplied by P1 is sent from the primary side forward header H1 to the secondary side forward header H2 through the pump bypass path 5 and supplied to the load device U (broken arrows in FIG. 1) (The state shown in).

  (L) Thereafter, the rotation speed of the primary pump P1 is adjusted by the inverter inv based on the measured cold water supply pressure pm by the pressure sensor Spm, thereby setting the cold water supply pressure pm (terminal pressure) for the end load device U to the set supply pressure pms. The state to be adjusted is entered, and the transition to the primary pump single operation is completed. (Supply pressure control by primary pump P1)

  The opening of the inter-header bypass valve 6v is fixed when the rotational speed of the secondary pump P2 is lowered to the adjustment lower limit by the inverter inv, and the opening is fixedly restricted in the primary pump single operation. The required throttle opening of the inter-bypass valve 6v is set.

  On the other hand, the control device 7 performs the transition from the primary pump single operation to the primary / secondary pump combined operation according to the following procedures (wo) to (yo). (See Figure 5)

<Transition from primary pump single operation to primary / secondary pump combined operation>
(W) When the calculated load heat amount G becomes larger than the set threshold heat amount Gs (G> Gs), one secondary pump P2 is started from the state at that time, and the rotation speed of the secondary pump P2 is determined by the inverter inv. Increase gradually from the lower limit of adjustment.

  (W) In the process of gradually increasing the rotational speed of the secondary pump, the opening degree of the pump bypass valve 5v is adjusted on the basis of the measured cold water supply pressure pm by the pressure sensor Spm, and the secondary bypass header H2 is passed through the pump bypass passage 5. In addition, the amount of cold water C supplied to the end load device U (end pressure) is adjusted to the set supply pressure pms by adjusting the recirculation amount of the cold water C to the primary side forward header H1 (indicated by a solid arrow in FIG. 1). Enter into control. (Supply pressure control by pump bypass valve 5v)

  (F) When the chilled water supply pressure pm (terminal pressure) to the end load device U reaches the set supply pressure pms by adjusting the opening of the pump bypass valve 5v, the measured differential pressure Δp (= ps−) by the differential pressure sensor Sdp pr) to adjust the opening degree of the inter-header bypass valve 6v so that the pressure difference state between the primary side forward header H1 and the return header RH indicates the chilled water pressure ps in the primary side forward header H1 is the return header. The inter-header differential pressure control is started to adjust the state so as to be higher than the cold water pressure pr in RH by a set pressure difference Δps. (Differential pressure control between headers)

  (Y) After that, the operation number and the rotational speed of the secondary pumps P2 are adjusted according to the measured chilled water flow rate Q, and the operation number and cooling capacity of the refrigerator 4 and the primary pump are determined according to the calculated load heat amount G. The state where the number of operating P1 and the number of revolutions are adjusted is entered, and the transition to the primary / secondary pump combined operation is completed.

[Another embodiment]
Next, other embodiments according to the present invention will be listed.

  In the above-described embodiment, an example in which the refrigerator 3 is a heat source device and the cold water C is a heat medium has been shown. However, in the case of a cold heat source system that circulates and supplies the heat medium C cooled by the heat source device 3 to the load device U, the heat source The machine 3 is not limited to various types of refrigerators, and various cooling heat source machines can be adopted as long as the heat medium C can be cooled, and the load is obtained by heat exchange with the stored heat storage material in the cold heat storage tank. A heat exchanger that cools the heating medium C supplied to the device U may be used as a heat source unit.

  In this case, the heat medium C is not limited to cold water, and various types such as brine and ice water slurry can be employed.

  The present invention can also be applied to a heat source system that supplies the heat medium C heated by the heat source device 3 to the load device U. In this case, the heat source device 3 can be various types of heating such as a hot water generator and a boiler. A heat exchanger that heats the supply heat medium C to the load device U by heat exchange with the stored heat storage material in the thermal heat storage tank may be used as the heat source device.

  In this case, various types of heat medium C such as warm water and steam can be adopted.

  In the above-described embodiment, an example in which the load heat amount G corresponding to the minimum adjustable capacity of the heat source unit group including the plurality of heat source units (refrigerators 3) is set as the set threshold heat amount Gs has been described. Gs is not necessarily limited to this, and the set threshold heat amount Gs may be appropriately set as long as both the primary and secondary pump combined operation and the primary pump single operation can be satisfactorily performed. .

  In the above-described embodiment, an example in which each of the plurality of secondary pumps P2 is a variable pump capable of adjusting the rotational speed has been described. Instead, only some of the secondary pumps P2 are variable pumps. The secondary pump P2 may be a pump having a fixed rotational speed. In this case, the variable secondary pump P2 is operated by operating at least one variable secondary pump P2 in each stage where the number of secondary pumps P2 is changed. What is necessary is just to enable it to adjust continuously the water supply capacity | capacitance as the whole secondary pump group to a lower limit capacity | capacitance by rotation speed adjustment of P2.

  Further, it is not necessary to make all the heat source devices 3 and the plurality of primary pumps P1 variable variable heat source devices or variable pumps, and only some heat source devices 3 and some primary pumps P1 are variable. Similarly to the above, by operating at least one set of variable heat source unit 3 and variable primary pump P1 in each stage where the number of operating heat source units 3 and primary pumps P1 is changed, the set of variable heat source units 3 And the variable primary pump P1 may be configured so that the capacity of the heat source machine group as a whole can be continuously adjusted to the lower limit capacity by adjusting the capacity and adjusting the number of times.

  The present invention can also be applied to a heat source system having only one heat source device 3 or primary pump P1 or a heat source system having only one secondary pump P2.

  In the above-described embodiment, an example in which the control means (control device 7) automatically executes mutual switching between the primary / secondary pump combined operation and the primary pump single operation according to the load heat amount G of the load device U. However, the operation switching may be performed by the control means 7 in accordance with the heat medium flow rate Q of the load device U, in accordance with an application command from an administrator, or in accordance with a set calendar. .

  In addition, either the primary / secondary pump combined operation or the primary pump single operation is performed as the initial operation, and thereafter, depending on the load heat amount G and the heat medium flow rate Q of the load device U or management The control means 7 may be made to perform switching to the other operation in response to a switching command from the person.

  The present invention can be applied to a heat source system used for various purposes in various fields.

H2 Secondary side forward header RH Return header 2 Secondary side flow path U Load device H1 Primary side forward header 1 Primary side flow path C Heat medium P1 Primary pump 3 Heat source machine 4 Relay path P2 Secondary pump G Load heat quantity Q Heat medium flow rate 7 Control means 5 Pump bypass passage 5v Pump bypass valve pm Heat medium supply pressure pms Set supply pressure 6 Header bypass passage 6v Header bypass valve Δps Set pressure difference Gs Setting side threshold heat amount Qs Setting threshold flow rate

Claims (9)

Load equipment is installed in the secondary side flow path connecting the secondary side forward header and return header,
A primary pump that sends a heat medium toward the primary-side forward header and a heat source device that cools or heats the heat medium are connected in series to a primary-side flow path that connects the return header and the primary-side forward header. Intervening in,
A relay path connecting the primary side forward header and the secondary side forward header is provided with a secondary pump that sends a heat medium toward the secondary forward header,
Depending on the switching command or the load heat amount of the load device or the heat medium flow rate in the load device, the heat medium is transferred between the heat source device and the load device by the operation of the primary pump and the secondary pump. Primary and secondary pump combined operation for circulation, and primary pump single operation for stopping the secondary pump and circulating the heat medium between the heat source device and the load device by the operation of the primary pump, A heat source system provided with control means for selectively performing
While providing a pump bypass path connecting the primary side forward header and the secondary forward header, a pump bypass valve is interposed in the pump bypass path,
In the combined operation of the primary and secondary pumps, the control means adjusts the opening degree of the pump bypass valve and heat medium from the secondary side forward header to the primary side forward header through the pump bypass path. By adjusting the recirculation amount, the heat medium supply pressure for the load device is adjusted to the set supply pressure,
In the primary pump single operation, the heat source configured to send the heat medium supplied by the primary pump from the primary side forward header to the secondary side header through the pump bypass passage with the pump bypass valve fully opened. system. While providing an inter-header bypass path connecting the primary side header and the return header, inter-header bypass valve is interposed in the inter-header bypass path,
The control means adjusts the opening degree of the inter-header bypass valve at the time of transition from the primary / secondary pump combined operation to the primary pump single operation, thereby adjusting the heat medium supply pressure to the load device. The heat source system according to claim 1, wherein the heat source system is configured to be adjusted to a set supply pressure.   The control means gradually decreases the rotation speed of the secondary pump as the rotation speed of the primary pump is gradually increased when the primary / secondary pump combined operation is shifted to the primary pump single operation. The heat source system according to claim 1, wherein the secondary pump is stopped.   In the primary pump single operation, the control means adjusts the rotation speed of the primary pump in a state where the opening degree of the inter-header bypass valve is limited or in a state where the inter-header bypass valve is closed, The heat source system according to claim 2 or 3, wherein a heat medium supply pressure for the load device is adjusted to a set supply pressure.   In the combined operation of the primary and secondary pumps, the control means adjusts the opening degree of the inter-header bypass valve so as to change the pressure difference state between the primary side forward header and the return header. The heat source system according to any one of claims 2 to 4, wherein the heat medium pressure in the next forward header is adjusted to be higher than the heat medium pressure in the return header by a set pressure difference.   The control means starts the secondary pump when the primary pump single-use operation shifts to the primary / secondary pump combined operation, and gradually increases the rotational speed of the secondary pump following the start-up. The heat source system according to any one of claims 2 to 5, which is configured.   When the heating medium supply pressure to the load device rises to a set supply pressure due to a gradual increase in the rotation speed of the secondary pump, the control means determines a pressure difference state between the primary forward header and the return header. The heat source system according to claim 6, wherein the control is started so that the heat medium pressure in the primary side forward header is adjusted to be higher than the heat medium pressure in the return header by a set pressure difference.   When the load heat amount of the load device is reduced to a set-side threshold heat amount or when the heat medium flow rate in the load device is reduced to a set threshold flow rate, the control means starts from the primary / secondary pump combined operation to the primary. The heat source system according to any one of claims 1 to 7, wherein the shift to single pump operation is automatically executed.   When the load heat amount of the load device has increased to a set threshold heat amount, or when the heat medium flow rate in the load device has increased to a set threshold flow rate, the control means starts the primary pump single operation from the primary pump single operation. The heat source system according to any one of claims 1 to 8, wherein a shift to the secondary pump combined operation is automatically executed.

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