JP2012225562A - Heat supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat supply system more excellent in an energy saving property than conventional ones by reducing energy consumption or energy loss at the operation start of a load terminal.SOLUTION: The heat supply system S includes an auxiliary channel 64 and a predetermined bypass channel 63, the auxiliary channel 64 connecting a second outward channel 62 to a tank 1 for a heating medium to constitute a heating medium circulation circuit C circulating the heating medium sent from a pump P through a decided route in a state with a valve V1 of a first load terminal 9A being closed. Control for an unsteady operation, which controls a heating operation of the heating medium based on a temperature Thb, is carried out when a detected temperature Tha by a temperature sensor Sa provided in a first outward channel 61 is higher than a temperature Thb of the heating medium returned to the tank 1 for the heating medium when the first load terminal 9A is operated.

Description

  The present invention relates to a heat supply system such as a hot water heating system, and more particularly to a heat supply system configured to supply heat to a desired load terminal such as a heating terminal using a heat medium such as antifreeze or water. .

As a conventional example of the hot water heating system, there is one as shown in FIG. 4 (see, for example, Patent Document 1).
In the hot water heating system Se shown in the figure, when the pump P connected to the supplementary water tank 1 is driven, the hot water passes through the first and second forward flow paths 61 and 62, and the first and second hot water flows. It is supplied to the load terminals 9A and 9B. Thereafter, the hot water that has passed through these returns to the refill water tank 1 via the return flow path 65 and circulates in a fixed path. The first load terminal 9A is, for example, a floor heating panel device, which is a so-called low temperature heating terminal. The second load terminal 9B is, for example, a fan convector and is a so-called high temperature heating terminal.
The second forward flow path 62 is provided with the heat exchanger 2 heated by the burner 4, and the hot water heated by the heat exchanger 2 can be supplied to the second load terminal 9B. is there. The first and second forward flow paths 61 and 62 are connected via a bypass flow path 63 provided with a check valve 50, and the heat exchanger 2 is connected to the hot water of the first forward flow path 61. It is possible to mix the hot water passed through and heated in the desired ratio. This mixing ratio can be changed using a flow rate adjusting valve V3 provided in the first forward flow path 61, and the temperature of the hot water supplied to the first load terminal 9A is changed by this changing operation. It can be changed. The first forward flow path 61 is provided with a temperature sensor Sa, and when the control unit 3e operates the first load terminal 9A, the temperature detected by the temperature sensor Sa is set to a desired target. It is configured to execute a control approaching the temperature.

  In such a hot water heating system Se, from the viewpoint of preventing water hammer and the like, the above-described valve V3 and the warm water inflow control valves V1 and V2 provided in the first and second load terminals 9A and 9B are provided. It is common to use a thermal valve. When the valves V1 and V2 are thermally operated valves, even if the operation command for opening the valves V1 and V2 is performed at the same time as the driving of the pump P is started, until the valves V1 and V2 are fully opened, For example, it takes about 1 minute and it is difficult to appropriately supply hot water to the first and second load terminals 9A and 9B during a period when the valve opening is small. On the other hand, the second forward flow path 62 is provided with an auxiliary flow path 64 for guiding the warm water of the second forward flow path 62 to the return flow path 65 and returning it to the refill water tank 1. According to such a configuration, during a period when the valve openings of the valves V1 and V2 are small, the hot water is caused to flow from the second forward flow path 62 to the auxiliary flow path 64 and circulate through a fixed path. Is possible.

  However, the prior art still has room for improvement as described below.

In other words, conventionally, when the first load terminal 9A is operated, the control is performed such that the temperature detected by the temperature sensor Sa is the predetermined target temperature Tht. This control is performed using the first load terminal 9A. The actual situation is that it is executed immediately from the time when the valve opening operation command for the valve V1 (energization to the valve V1) is made to operate 9A. On the other hand, immediately after the valve opening operation command to the valve V1 is made, when the valve V1 is a thermally operated valve, the valve opening degree is small. It circulates so that it may return to the supplementary water tank 1 via the auxiliary flow path 64 from the outgoing flow path 62. For this reason, hot water is not supplied to the place where the temperature sensor Sa is provided. In such a state, even if hot water heating using the heat exchanger 2 is performed, the temperature Tha detected by the temperature sensor Sa does not rise properly. Therefore, during such a period, if the temperature detected by the temperature sensor Sa is controlled to be the target temperature Tht, the hot water is heated to a temperature higher than the target temperature Tht. In this case, the hot water is heated more than necessary, and the energy consumed for the heating may be wasted, and the heat loss due to heat dissipation during the hot water circulation also increases. Such a situation is desired to be improved from the viewpoint of energy saving. Conventionally, there is also a problem that hot water having a temperature higher than the target temperature Tht is supplied when the hot water supply to the first load terminal 9A is started.

Japanese Patent Publication No.7-113458

  The present invention has been conceived under the circumstances as described above, and reduces energy consumption or energy loss at the start of operation of the load terminal, and is superior in energy saving performance than in the past. An object of the present invention is to provide a heat supply system that can be used.

  In order to solve the above problems, the present invention takes the following technical means.

  The heat supply system provided by the present invention is provided to be branched downstream of a pump capable of delivering the heat medium in the heat medium tank and to guide the heat medium to the first and second load terminals. The first and second forward flow paths, heating means for heating the heat medium flowing through the second forward flow path, and the heat medium heated by the heating means as the first forward flow path. A bypass flow path connecting the first and second forward flow paths so as to be allowed to flow in, and a heating medium inflow control valve of the first load terminal being closed when the pump is driven In addition, the second forward flow is configured such that a heat medium circulation circuit is configured to return the heat medium sent from the pump to the second forward flow path to the heating medium tank and circulate it through a fixed path. Auxiliary flow path connecting the path to the heating medium tank and the first load terminal The first temperature sensor provided in the first forward flow path so that the temperature of the heat medium to be detected can be detected, and in the steady operation in which the heat medium is supplied to the first load terminal, the first temperature sensor And a control means for controlling the heating operation of the heat medium based on the temperature detected by the temperature sensor, wherein the heat supply system passes through the auxiliary flow path and is returned to the heat medium tank. A second temperature sensor for detecting a temperature; and when the control means operates the first load terminal, the temperature detected by the second temperature sensor is determined by the first temperature sensor. When the temperature is higher than the detected temperature, unsteady operation is controlled, and in this unsteady operation control, the heating operation of the heat medium is controlled based on the temperature detected by the second temperature sensor. Special It is set to.

According to such a configuration, the following effects can be obtained.
That is, when operating the first load terminal, when the temperature detected by the second temperature sensor is higher than the temperature detected by the first temperature sensor, the first load terminal is used for heat medium inflow control of the first load terminal. It is considered that the valve is still closed, and the heat medium circulates in the heat medium circulation circuit and is not supplied to the installation location of the first temperature sensor. During such a period, control of unsteady operation is performed, and control for heating the heat medium is performed based on the temperature detected by the second temperature sensor. The temperature detected by the second temperature sensor indicates the actual temperature of the heating medium that is heated by the heating means and circulates in the heating medium circulation circuit. Therefore, the heating medium heating operation includes the actual heating medium temperature. The heating operation control corresponding to the above is appropriately executed. Therefore, unlike the prior art where the heating medium heating operation is performed based on the temperature detected by the first temperature sensor even though the valve of the first load terminal is still closed, a heating medium is required. It is possible to eliminate waste such as heating to a high temperature. As a result, the energy consumption or energy loss at the start of operation of the first load terminal can be reduced as compared with the prior art, and the energy saving performance can be improved.

  In the present invention, it is preferable that the control unit performs control in which the temperature detected by the first temperature sensor is set to a predetermined target temperature during the steady operation, and in the control of the unsteady operation, Control is performed so that the temperature detected by the second temperature sensor is a predetermined target temperature.

  According to such a configuration, it is possible to supply a heat medium at an appropriate temperature to the first load terminal during steady operation, and at the start of operation of the first load terminal, When the valve of the load terminal is not yet fully open and the heating medium is circulating in the heating medium circulation circuit, heating the heating medium at a temperature higher than the target temperature is appropriately prevented. For this reason, it is possible to accurately prevent the heating medium from being heated unnecessarily, and to reduce heat loss during circulation of the heating medium. Furthermore, it is possible to eliminate the possibility that the heat medium having a temperature higher than the target temperature will be supplied to the first load terminal thereafter.

  In the present invention, preferably, the control means is configured to make the drive speed of the pump slower than in the steady operation in the control of the unsteady operation.

  According to such a configuration, when the heat medium circulates in the heat medium circulation circuit at the start of operation of the first load terminal, the circulation flow rate of the heat medium decreases, so that the heat dissipation loss is less. Become. In addition, power consumption required for driving the pump can be reduced.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is explanatory drawing which shows an example of the hot water heating system as a heat supply system which concerns on this invention. It is a flowchart which shows an example of the operation processing procedure of the control part of the hot water heating system shown in FIG. It is a flowchart which shows the other example of the operation | movement process procedure of the control part of the hot water heating system shown in FIG. It is explanatory drawing which shows an example of a prior art.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  The hot water heating system S shown in FIG. 1 corresponds to an example of the heat supply system according to the present invention, and the hardware configuration has many parts in common with the conventional hot water heating system Se described with reference to FIG. . Therefore, hereinafter, the same reference numerals are used for the same or similar elements as the constituent elements of the conventional hot water heating system Se.

The hot water heating system S is provided with a pump P connected to the replenishing water tank 1 in a state branched to the downstream side of the pump P, and the first and second load terminals 9A and 9B are provided at the end portions 61a and 62a. The connected first and second forward flow paths 61 and 62, the heat exchanger 2 for hot water heating provided in the second forward flow path 62, the bypass flow path 63 provided with the check valve 50, the auxiliary flow A path 64, a return flow path 65, first to third temperature sensors Sa to Sc, and a control unit 3 are provided.

  The supplementary water tank 1 corresponds to an example of a tank for a heat medium referred to in the present invention. The heat medium used as warm water is, for example, an antifreeze solution, but ordinary water can be used instead. The first and second load terminals 9A and 9B are the same as those in the prior art shown in FIG. 4, and the first load terminal 9A is a so-called low-temperature heating terminal, for example, a panel device for floor heating. . The second load terminal 9B is a so-called high temperature heating terminal, for example, a fan convector. It is also possible to connect a plurality of second load terminals 9B to the end portion 62a of the second forward flow path 62. The first and second load terminals 9A, 9B are provided with valves V1, V2 for hot water inflow control (for heat medium inflow control) using a thermal valve.

  The heat exchanger 2 can heat the hot water passing through the second forward flow path 62 by recovering heat from the high-temperature combustion gas generated by the burner 4 such as a gas burner. Therefore, the combination of the heat exchanger 2 and the burner 4 corresponds to an example of the heating means in the present invention. When the valve V2 is in the open state, the hot water heated by the heat exchanger 2 can be supplied to the second load terminal 9B as it is, and the second load terminal 9B can be operated. During the operation of the second load terminal 9B, the hot water temperature detected using the third temperature sensor Sc provided in the vicinity of the outlet side of the heat exchanger 2 is controlled to be a desired target temperature. The The hot water that has passed through the second load terminal 9B is guided to the return flow path 65 via the pipe 90b and returned to the water replenishment tank 1.

  The bypass flow path 63 connects a portion of the second forward flow path 62 downstream of the heat exchanger 2 and a portion of the first forward flow path 61 downstream of the flow rate adjusting valve V3. Yes. When the valve V1 is in the open state, hot water is supplied from the pump P to the first load terminal 9A via the first outgoing flow path 61. In this case, the second water is supplied via the bypass flow path 63. It is possible to flow the warm water of the forward flow path 62 into the first forward flow path 61 and mix the warm water. It is possible to control the temperature of the hot water supplied to the first load terminal 9A by changing the mixing ratio by the valve opening degree control of the valve V3. The temperature of this hot water can be detected using the first temperature sensor Sa. The hot water that has passed through the first load terminal 9A is guided to the return flow path 65 via the pipe 90a and returned to the water replenishment tank 1.

  The auxiliary flow path 64 connects the portion of the second forward flow path 62 downstream of the heat exchanger 2 and the return flow path 65. As a result, in the hot water heating system S, when the valves V1 and V2 are in the closed state, the hot water sent from the pump P is supplied to the second forward flow path 62, the auxiliary as shown by arrows N1 to N4. A heat medium circulation circuit C is configured to flow sequentially through the flow path 64 and the return flow path 65 and return to the refill water tank 1 to circulate and circulate hot water through a fixed path. The second temperature sensor Sb is provided in the return flow path 65 so as to be able to detect the temperature of the warm water returned to the refill water tank 1.

  The control unit 3 corresponds to an example of the control means in the present invention, and is configured using, for example, a microcomputer. This control part 3 performs operation control of each part of the hot water heating system S and various data processing, but when operating the first load terminal 9A, it performs operation control different from that of the prior art. However, the specific content will be described later.

  Next, an example of the operation of the hot water heating system S and an operation processing procedure of the control unit 3 will be described with reference to the flowchart shown in FIG.

First, when the pump P and the burner 4 are stopped and the first and second load terminals 9A and 9B are in an operation stop state in which the valves V1 and V2 are closed, a remote controller (not shown) or the like Is operated to drive the first load terminal 9A, the control unit 3 drives the pump P, energizes the valve V1 for valve opening operation, and turns on the burner 4. Drive (S1: YES, S2). Next, the control unit 3 compares the detected temperatures Tha and Thb detected by the first and second temperature sensors Sa and Sb, and determines that the valve V1 is not yet opened when Tha <Thb. Then, unsteady operation is controlled (S3: YES, S4). In this unsteady operation control, control is performed such that the detected temperature Thb detected by the second temperature sensor Sb is the desired target temperature Tht.

  For example, it takes about one minute for the valve V1 that is a heat operated valve to be in the open state. During this period, the hot water circulates in the heat medium circuit C as indicated by arrows N1 to N4. is doing. The hot water heated by the heat exchanger 2 is supplied to the place where the second temperature sensor Sb is provided, but is not supplied to the place where the first temperature sensor Sa is provided. Therefore, when the relationship of Tha <Thb is satisfied, it may be determined that the valve V1 is not yet opened and that the hot water is circulating in the heat medium circuit C. In such a situation, unlike the operation processing described above, for example, when control is performed with the temperature detected by the first temperature sensor Sa as the target temperature Tht, the hot water is set to a temperature higher than the target temperature Tht. This causes a problem of heating. On the other hand, in this embodiment, such a malfunction can be eliminated. Therefore, the waste of heating the hot water to an unnecessarily high temperature is eliminated, the fuel consumed by the burner 4 is saved, and the heat loss due to heat radiation when the hot water circulates through the heat medium circuit C is reduced. It can be excellent in energy saving. Further, when the valve V1 is subsequently opened, it is possible to eliminate the problem that hot water having a temperature higher than the target temperature Tht is supplied to the first load terminal 9A.

  When the valve V1 is in the open state, the state in which the hot water circulates through the heat medium circulation circuit C is eliminated, and the first load sensor 9A is heated to the place where the first temperature sensor Sa is provided. Hot water heated through the exchanger 2 can be supplied via the bypass flow path 63. Hot water after passing through the first load terminal 9A is supplied to the place where the second temperature sensor Sb is provided. As a result, the detected temperatures Tha and Thb satisfy Tha ≧ Thb. When detecting such a state, the control unit 3 determines that the valve V1 has been opened, and starts control of steady operation (S3: NO, S5). The control of the steady operation is control in which the detected temperature Tha by the first temperature sensor Sa is set as the target temperature Tht. When the operation of the first load terminal 9A is finished, the burner 4 and the pump P are stopped and the valve V1 is closed (S6: YES, S7). Then, the above-described steady operation control is continuously executed (S6: NO).

  According to the above-described series of operation control, it is determined whether or not the valve V1 is open based on the detected temperatures Tha and Thb, and until the valve V1 changes from the closed state to the open state, As described above, the hot water is prevented from being heated to an unnecessarily high temperature, and energy saving is appropriately achieved. On the other hand, after the valve V1 is opened, the first load terminal 9A can be appropriately operated by switching to the steady operation state.

  It is also possible for the control unit 3 to execute operation control as shown in the flowchart of FIG.

  In the flowchart of FIG. 3, steps having the same contents as those in the flowchart of FIG. 2 are given the same reference numerals, and the contents of steps S4 'and S5' are different from the contents shown in FIG. In the operation processing procedure shown in FIG. 3, when the operation of the first load terminal 9A is started, the valve V1 is not yet opened, and hot water circulates through the heat medium circulation circuit C, and during a period in which Tha <Thb, The control part 3 performs control which makes the drive speed of the pump P slower than the time of steady operation as control of unsteady operation (S3: YES, S4 ').

According to the control as described above, although there is a possibility that the hot water is heated to a temperature higher than the target temperature Tht, since the driving speed of the pump P is lowered, the power consumption required for driving the pump P is suppressed. Is done. In addition, the flow rate of hot water (flow rate per unit time) in the heat medium circulation circuit C is reduced. When hot water circulates in the heat medium circuit C at high speed and the flow rate of hot water is large, the amount of heat released from the hot water also increases. However, according to the control described above, the amount of heat released from the hot water is suppressed, This also has the effect of reducing loss. Therefore, the energy saving performance can be enhanced by the operation process shown in FIG. 3 as compared with the prior art. When the valve V1 is opened and Tha ≧ Thb, the control unit 3 sets the driving speed of the pump P at that time to the original speed for steady operation (S3: NO, S5 ′).
The control unit 3 is caused to perform control (control for executing both steps S4, S4 ′ and steps S5, S5 ′) that combines the operation control shown in FIG. 2 and the operation control shown in FIG. It is also possible. According to such a configuration, further energy saving can be achieved.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the heat supply system according to the present invention can be variously modified within the range intended by the present invention.

  The heating means for heating the heat medium flowing through the second forward flow path is not limited to the heat exchanger heated by the burner, and for example, the heat medium can be heated by heat exchange with another heating fluid. It can also be used as a heat exchanger. When the heat supply system according to the present invention is configured as, for example, a cogeneration system including a gas engine or a fuel cell, the high-temperature gas discharged from the gas engine or the fuel cell is used to perform the second outbound. Heating the heat medium in the flow path, or heating the heat medium in the second forward flow path using hot water heated using the above-described high-temperature gas or hot water stored in a hot water storage tank It is also possible.

  In the present invention, the control of the unsteady operation when the detected temperatures Tha, Thb detected by the first and second temperature sensors Sa, Sb satisfy Tha <Thb is basically the detected temperature detected by the second temperature sensor Sb. Any content may be used as long as the heating operation of the heat medium is controlled based on Thb. At the time of unsteady operation, instead of controlling the detected temperature Thb detected by the second temperature sensor Sb as the target temperature Tht as described above, for example, the heating amount of the heating medium by the heating means (for example, the burner 4 shown in FIG. 1). Is controlled to a predetermined content corresponding to the temperature Thb detected by the second temperature sensor Sb, and the heating amount of the heat medium by the heating means is based on the temperature detected by the first temperature sensor Sa. Thus, it is possible to adopt a means for controlling the heating medium so that it is reduced by a predetermined ratio as compared with the case of heating the heating medium.

  The heat supply system according to the present invention can also be configured as a system not intended for heating. That is, as a load terminal, for example, a terminal such as a heat exchanger for bathing and a panel for melting snow may be used, and a system without a heating terminal may be used. Of course, a system in which heating terminals and non-heating terminals are mixed can also be used. As the heating terminal, for example, a bathroom heating dryer can be applied in addition to a floor heating panel device or a convector. In the hot water heating system, antifreeze or tap water is suitably used as the heat medium, but in the present invention, other fluids can be used as the heat medium.

S Hot water heating system (heat supply system)
C Heat-medium circulation circuit P Pump Sa 1st temperature sensor Sb 2nd temperature sensor V1, V2 Valve for warm water inflow control (valve for heat medium inflow control)
1 Water replenishment tank (heat medium tank)
2 Heat exchanger (heating means)
3 Control unit (control means)
4 Burner (heating means)
9A First load terminal 9B Second load terminal 61 First forward flow path 62 Second forward flow path 63 Bypass flow path 64 Auxiliary flow path 65 Return flow path

Claims (3)

First and second forward flow paths that are provided on a downstream side of a pump capable of delivering the heat medium in the heat medium tank, and that guide the heat medium to the first and second load terminals. ,
Heating means for heating the heat medium flowing through the second forward flow path;
A bypass flow path connecting the first and second forward flow paths so that the heating medium heated by the heating means can flow into the first forward flow path;
When the heat medium inflow control valve of the first load terminal is closed when the pump is driven, the heat medium sent from the pump to the second forward flow path is transferred to the heat medium tank. An auxiliary flow path that connects the second forward flow path to the heat medium tank so that a heat medium circulation circuit that circulates in a fixed path is configured.
A first temperature sensor provided in the first forward flow path so as to detect the temperature of the heat medium supplied to the first load terminal;
Control means for controlling the heating operation of the heating medium based on the temperature detected by the first temperature sensor during the steady operation in which the heating medium is supplied to the first load terminal;
A heat supply system comprising:
A second temperature sensor for detecting the temperature of the heat medium returned to the heat medium tank through the auxiliary flow path;
The control means, when operating the first load terminal, performs unsteady operation control when the temperature detected by the second temperature sensor is higher than the temperature detected by the first temperature sensor, In addition, in the control of the unsteady operation, the heat supply system is configured to control the heating operation of the heat medium based on the temperature detected by the second temperature sensor. The heat supply system according to claim 1,
The control means executes control to set the temperature detected by the first temperature sensor as a predetermined target temperature during the steady operation, and uses the second temperature sensor to control the non-steady operation. A heat supply system configured to execute control with a detected temperature as a predetermined target temperature. The heat supply system according to claim 1 or 2,
In the control of the unsteady operation, the control means is configured to make the drive speed of the pump slower than that in the steady operation.

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