JP5542574B2 - Hot water circulation system - Google Patents

Description

  The present invention relates to a hot water circulation system in which heated hot water is supplied to a hot water terminal to dissipate heat.

  Conventionally, a hot water terminal is provided with a gas heat source device, a hot water circulation path communicating with the gas heat source machine and the hot water terminal, and a pump for circulating hot water in the hot water circulation path. There is known a hot water circulation system that supplies heat to a heat sink (see, for example, Patent Document 1).

  In the gas heat source device of the hot water circulation system described in Patent Document 1, the hot water in the hot water circulation path is heated by heating a heat exchanger provided in the middle of the hot water circulation path with a burner. Then, during the heating operation, burners consisting of a plurality of burner units are burned on the entire surface (all the burner units are burned) so that the temperature of the hot water discharged from the gas heat source machine to the hot water circulation path becomes the target temperature. Temperature control is performed by performing burner ON / OFF control for switching the ratio between the burner combustion time and the fire extinguishing time in a predetermined control cycle in a state where the thermal power is increased to some extent and the heat efficiency is high.

  In this way, by performing ON / OFF control by burning the entire surface of the burner, it is possible to improve the thermal efficiency at the time of temperature control, compared with the case where the number of burner units to be burned is reduced to adjust the thermal power.

JP 2007-285625 A

  In the gas heat source machine, two on-off valves are provided at different locations of the gas supply pipe communicating with the gas burner, and when the gas burner is in a fire extinguishing state, the two on-off valves are both closed. The reliability of shutting off the supply of fuel gas to the gas burner is maintained.

  When the burner ON / OFF control is executed, the two on-off valves are both opened when the gas burner is on (combustion), and the two on-off valves are both closed when the gas burner is off (when extinguishing). Therefore, the two opening / closing valves are required to have durability corresponding to frequent opening / closing by the burner ON / OFF control. Therefore, when the gas solenoid valve used in the gas heat source machine of the hot water circulation system with the specification not performing the burner ON / OFF control is employed, there is a possibility that a problem in durability may arise.

  The present invention has been made in view of such a background, and has ensured the reliability of shutting off the supply of fuel gas to the gas burner during fire extinguishing, and has relaxed the durability condition required for the on-off valve. The purpose is to provide.

The present invention has been made to achieve the above object, and includes a gas burner having a first burner unit and a second burner unit, a combustion sensor for detecting a combustion state of the gas burner, a gas supply path, and the gas supply. A first gas branch path branched from the path and connected to the first burner unit; a second gas branch path branched from the gas supply path and connected to the second burner unit; and the gas supply path A gas source valve that opens and closes the gas supply path; a first capacity switching valve that opens and closes the first gas branch path; and a second gas branch path that opens and closes the first gas branch path. A second capacity switching valve provided to open and close the second gas branch path; a heat exchanger heated by the gas burner; a hot water circulation path communicating the heat exchanger and a hot water terminal; and the heat exchange Heated by the vessel A circulating pump for sending hot water to the hot water terminal via the hot water circulation path and returning hot water radiated from the hot water terminal to the heat exchanger, and a temperature of the hot water supplied from the hot water circulation path to the hot water terminal Or burner ON / OFF control for intermittently burning one or both of the first burner unit and the second burner unit so that the temperature of the warm water returning from the warm water terminal to the warm water circulation path falls within a predetermined temperature range. It is related with the improvement of a hot water circulation system provided with the combustion control part which performs.

In the burner ON / OFF control, the combustion control unit opens the gas source valve and opens one or both of the first capacity switching valve and the second capacity switching valve to open the gas burner. When the gas burner is extinguished from the state of burning , the first capacity switching valve and the second capacity switching valve are controlled to be closed while the gas source valve is kept open , and the combustion is performed. Whether or not the gas burner is extinguished is detected by a sensor, and when the gas burner is extinguished, the first capability switching valve and the second capability switching valve are maintained in a closed state, and The gas burner is maintained in a fire extinguishing state, and when the fire of the gas burner is not detected, the gas source valve is also controlled to be closed (first invention).

According to the first invention, the combustion control unit maintains the gas source valve in an open state on condition that the combustion sensor detects fire extinguishing of the gas burner in the gas burner ON / OFF control. The first capability switching valve and the second capability switching valve are controlled to be closed to maintain the gas burner in a fire extinguishing state. Therefore, in the burner ON / OFF control, the gas main valve, the first capacity switching valve, and the second capacity switching valve are both closed to extinguish the gas burner. The number of opening and closing operations is reduced, and the durability condition required for the gas source valve can be relaxed. When the combustion sensor does not detect fire extinguishing of the gas burner when the first capacity switching valve and the second capacity switching valve are controlled to be closed while the gas source valve is kept open. The gas source valve is also controlled to be closed, thereby ensuring the reliability of shutting off the fuel gas when the gas burner is extinguished.

In the burner ON / OFF control, the combustion control unit maintains the gas source valve in an open state in a state where the gas burner is burned, and the first capacity switching valve and the second capacity switching. When the valve is controlled to be closed, if a fire extinguishing of the gas burner is not detected by the combustion sensor, a failure notifying unit for notifying a failure is provided (second invention).

In the second invention, when the gas burner is burned and the gas source valve is maintained in an open state, the first capacity switching valve and the second capacity switching valve are controlled to be closed. When fire extinguishing of the gas burner is not detected by the sensor, it can be determined that a failure of the first capacity switching valve or the second capacity switching valve has occurred. Therefore, in this case, the failure notification is performed by the failure notification unit, thereby prompting the user to repair the first capability switching valve or the second capability switching valve .

The block diagram of a warm water circulation system. The block diagram of the controller shown in FIG. The flowchart of burner ON / OFF control.

  An embodiment of the present invention will be described with reference to FIGS. With reference to FIG. 1, the hot water circulation system 1 of this embodiment connects the gas heat source machine 2, the hot water heating terminal 3 (corresponding to the hot water terminal of the present invention), and the gas heat source machine 2 and the hot water heating terminal 3. A hot water circulation path 4 and a controller 10 that controls the overall operation of the hot water circulation system 1 are provided.

  The gas heat source unit 2 applies a high voltage to the gas burner 21 composed of a large burner unit 21a and a small burner unit 21b that form two large and small combustion surfaces, an ignition electrode 31 for igniting the gas burner 21, and an ignition power 31. Thus, an igniter 30 that generates a spark discharge, a flame rod 32 that detects a combustion flame of the gas burner 21 (corresponding to a combustion sensor of the present invention), a heat exchanger 22 that is heated by the gas burner 21, and combustion air to the gas burner 21. A fan 23 to be supplied and a supply / exhaust pipe 24 for taking in combustion air by the fan 23 and exhausting the combustion exhaust gas of the gas burner 21 are provided.

  The hot water circulation system 1 heats the hot water circulating in the heat exchanger 22 by the combustion exhaust gas of the gas burner 21 and supplies the hot water to the hot water heating terminal 3 to dissipate heat, thereby heating the surroundings of the hot water heating terminal 3. .

  In the hot water circulation path 4, the hot water heated by the heat exchanger 22 is sent to the hot water heating terminal 3, and the hot water radiated from the hot water heating terminal 3 is returned to the heat exchanger 22, and the gas heat source unit 2. And a return temperature sensor 4c for detecting the temperature of the hot water returning from the hot water heating terminal 3 to the gas heat source unit 2 is provided.

  The gas branch passages 61a and 61b branched from the gas supply passage 61 and connected to the gas burner 21 have first capability switching valves 62a for individually switching the supply / cutoff of the fuel gas to the large burner unit 21a and the small burner unit 21b. And the 2nd capability switching valve 62b is provided. Further, the gas supply path 61 includes a gas source valve 61c that collectively switches the supply / cutoff of the fuel gas to the large burner unit 21a and the small burner unit 21b, and the fuel gas to the large burner unit 21a and the small burner unit 21b. And a proportional valve 7 for changing the supply flow rate.

The branch path 61a provided with the first capacity switching valve 62a corresponds to the first gas branch path of the present invention, and the large burner unit 21a connected to the branch path 61a corresponds to the first burner unit of the present invention. . The branch path 61b provided with the second capacity switching valve 62a corresponds to the second gas branch path of the present invention, and the small burner unit 21b connected to the branch path 61b corresponds to the second burner unit of the present invention. .

  In addition, a remote controller 5 is connected to the controller 10, and a user operates a switch provided on the remote controller 5 to start / stop the heating operation of the hot water heating terminal 3 and set the heating capacity.

  Next, referring to FIG. 2, the controller 10 is an electronic unit including a CPU, a memory, and the like (not shown). By causing the CPU to execute a control program for the hot water circulation system 1, the controller 10 When a failure is detected in the combustion control unit 11 that performs the heating operation for supplying the hot water heated by the exchanger 22 to the hot water heating terminal 3, and the gas source valve 61c, the first capacity switching valve 62a, or the second capacity switching valve 62b It functions as a failure notification unit 12 that performs failure notification.

  The controller 10 receives a temperature detection signal from the forward temperature sensor 4b, a temperature detection signal from the return temperature sensor 4c, and a flame detection signal Fs from the frame rod 32. Further, the operation of the circulation pump 4a, the fan 23, the igniter 30, the proportional valve 7, the gas source valve 61c, the first capacity switching valve 62a, and the second capacity switching valve 62b is controlled by the control signal output from the controller 10. Is done.

  In addition, the controller 10 inputs an operation signal of the heating switch 5b output from the remote controller 5 and outputs display data of the display unit 5a to the remote controller 5 to display the operation status of the hot water circulation system 1 to the display unit 5a. Display.

  The combustion control unit 11 opens and closes the first capacity switching valve 62a and the second capacity switching valve 62b to switch the effective combustion range (combustion surface range) of the gas burner 21 into three stages of large, medium, and small. That is, the combustion control unit 11 opens both the first capacity switching valve 62a and the second capacity switching valve 62b, thereby causing both the large burner unit 21a and the small burner unit 21b to burn together, and a stage having a large effective combustion range. By opening the first capability switching valve 62a and closing the second capability switching valve 62b, the stage in the effective combustion range in which only the large burner unit 21a is combusted, and the first capability switching valve 62a are closed. By opening the second capacity switching valve 62b, the stage of the effective combustion range in which only the small burner unit 21b is combusted is switched. Furthermore, the combustion control unit 11 adjusts the heating power of the gas burner 21 by changing the opening degree of the proportional valve 7 at each stage of the effective combustion range large, medium, and small.

  Next, the heating operation process by the combustion control unit 11 and the failure notification process by the failure notification unit 12 will be described according to the flowchart shown in FIG.

  In STEP 1 of FIG. 3, when it is recognized from the operation signal received from the remote controller 5 that the heating switch 5 b of the remote controller 5 has been operated (heating start operation), the combustion control unit 11 proceeds to STEP 2 and performs the ignition process of the gas burner 21. I do. Specifically, the combustion control unit 11 operates the fan 23 and applies a high voltage from the igniter 30 to the ignition electrode 31 to generate a spark discharge. The switching valve 62b and the gas source valve 61c are opened, and the gas burner 21 is ignited.

By the subsequent loop of STEP3 to STEP9, the combustion control unit 11 extinguishes the gas burner 21 when the detected temperature Ts2 of the return temperature sensor 4c becomes equal to or higher than the burner extinguishing temperature _TOFF, and the detected temperature Ts2 of the return temperature sensor 4c becomes the burner. The process of igniting the gas burner 21 when the ignition temperature T _ON or lower is repeated, and the return temperature from the hot water heating terminal 3 is kept in the range of T _{OFF to} T _ON (corresponding to the predetermined temperature range of the present invention). “Burner ON / OFF control” is executed.

  Note that STEP 3 to STEP 9 show an example in which the effective combustion range of the gas burner 21 is increased and “burner ON / OFF control” is executed.

In the loop of STEP3 to STEP4, the combustion control unit 11 determines whether or not the heating switch 5b of the remote controller 5 has been operated (heating stop operation) in STEP3. It is determined whether or not T _OFF or less.

  When the heating stop operation is performed in STEP 3, the process branches to STEP 20, and the combustion control unit 11 performs OFF control (closed control) on the gas source valve 61 c in STEP 20, and the first capacity switching valve 62 a and the second capacity switching in STEP 21. The valve 62b is turned off (closed control), and the gas burner 21 is extinguished. Then, returning to STEP 1, the combustion control unit 11 waits for a heating start operation to be performed.

Further, when the detected temperature Ts2 of the return temperature sensor 4c is equal to or higher than the burner extinguishing temperature _TOFF in STEP4, the process proceeds to STEP5, and when the detected temperature Ts2 of the return temperature sensor 4c is lower than the burner extinguishing temperature _TOFF , the process returns to STEP3.

In STEP 5, the combustion control unit 11 performs OFF control (closed control) on the first capacity switching valve 62a and the second capacity switching valve 62b (the gas source valve 61c maintains the valve open state). Then, through the subsequent STEP 6 to STEP 8 loop, the combustion control unit 11 determines whether or not the gas burner 21 has been extinguished from the detection signal of the frame rod 32 in STEP 6, and determines whether or not the heating stop operation has been performed in STEP 7. , the detected temperature Ts2 of the temperature sensor 4c back in STEP8 to determine whether it is below the burner ignition temperature T _oN.

  Here, when the fire extinguishing of the gas burner 21 is not detected in STEP 6, the supply of the fuel gas to the gas burner 21 is performed in spite of performing the OFF control of the first capacity switching valve 62a and the second capacity switching valve 62b in STEP 5. Since the state is not shut off, it can be determined that at least one of the first ability switching valve 62a and the second ability switching valve 62b is in a valve opening failure state.

  Therefore, in this case, the process branches from STEP 6 to STEP 30, and the combustion control unit 11 performs OFF control (valve closing control) on the gas source valve 61c. Then, in subsequent STEP 31, the failure notification 12 displays a notification of the occurrence of the failure on the display unit 5a of the remote controller 5 (failure notification), and proceeds to STEP 32 to end the process.

  Here, since it can be assumed that it is extremely rare that one of the first capacity switching valve 62a and the second capacity switching valve 62b and the gas source valve 61c simultaneously fail, the gas source valve 61c is controlled to be OFF. Thus, it can be expected that the supply of the fuel gas to the gas burner 21 is stopped.

  When the heating stop operation is performed in STEP 7, the process branches to STEP 40, and the combustion control unit 11 turns off the gas source valve 40 and returns to STEP 1 to wait for the heating start operation.

When the detected temperature Ts2 of the temperature sensor 4c back in STEP8 is below the burner ignition temperature T _ON, the process proceeds to STEP 9, when the detected temperature Ts2 of the return temperature sensor 4c is higher than the burner ignition temperature T _ON Back to STEP6.

  In STEP 9, the combustion control unit 11 performs an ignition process for the gas burner 21. Here, since the gas source valve 61c is maintained in the open state, the combustion control unit 11 operates the fan 23 and applies a high voltage from the igniter 30 to the ignition electrode 31 to cause spark discharge. In this state, the first capacity switching valve 62a and the second capacity switching valve 62b are ON-controlled (valve control) to ignite the gas burner 21, and the process returns to STEP3.

  In “burner ON / OFF control” in STEP3 to STEP9, it is detected that the gas burner 21 has been extinguished in STEP6 in accordance with the OFF control of the first capability switching valve 62a and the second capability switching valve 62b in STEP5. As a condition, in STEP5 and STEP9, the first capability switching valve 62a and the second capability switching valve 62b are ON / OFF controlled (the gas source valve 61c is kept open) to burn the gas burner 21 intermittently.

  In this case, the gas source valve 61c is maintained in an open state, and ON / OFF switching is not performed. For this reason, the gas source valve 61c can be used which has a lower number of opening / closing operations and is less durable than the first capability switching valve 62a and the second capability switching valve 62b.

  When the first capacity switching valve 62a or the second capacity switching valve 62b fails, the gas source valve 61c is closed at STEP 30 branched from STEP 6, so the first capacity switching valve 62a and the second capacity switching valve. The reliability of the fuel gas supply cutoff by providing the 62b and the gas main valve 61c at different positions of the gas supply pipe 61 is ensured.

  In this embodiment, when the first capability switching valve 62a and the second capability switching valve 62b are turned off in STEP5 of FIG. 3, if the fire extinguishing of the gas burner 21 is not detected in STEP6, the gas is detected in STEP30. While the main valve 61c is closed and the failure notification is performed in STEP 31, the effect of the present invention can be obtained even when this failure notification is not performed.

  Moreover, in this embodiment, although the warm water heating terminal 3 was shown as a warm water terminal of this invention, if it is a warm water terminal using the warm water supplied from the gas heat source machine 2 as a heat source, for example, it will dry clothes using warm water as a heat source. Another type of hot water terminal such as a clothes dryer that generates hot air for the use may be used.

Further, in the present embodiment, as shown in the flowchart of FIG. 3, the combustion control unit 11 is configured so that the detected temperature Ts2 of the return temperature sensor 4c is within a predetermined range (T _ON ≦ Ts2 ≦ T _OFF ). Although the burner ON / OFF control for intermittently burning the gas burner 21 is performed, the burner ON / OFF control for intermittently burning the gas burner 21 is performed so that the detected temperature Ts1 of the forward temperature sensor 4b is within a predetermined range. You may do it.

  Further, in the present embodiment, the combustion control unit 11 increases the effective combustion range of the gas burner 21 and simultaneously switches the opening and closing of the first capacity switching valve 62a and the second capacity switching valve 62b, thereby Although the ON / OFF control is performed, when the effective combustion range of the gas burner 21 is set to the middle, the second capacity switching valve 62b is kept closed and only the first capacity switching valve 62a is switched between opening and closing. Then, burner ON / OFF control may be performed. Further, when the effective combustion range of the gas burner 21 is made small, the burner ON / OFF control is performed by keeping the first capability switching valve 62a closed and switching between the opening and closing of only the second capability switching valve 62b. Just do it.

  DESCRIPTION OF SYMBOLS 1 ... Warm water circulation system, 2 ... Gas heat source machine, 3 ... Warm water heating terminal, 4 ... Warm water circulation path, 4a ... Circulation pump, 4b ... Outward temperature sensor, 4c ... Return temperature sensor, 5 ... Remote control, 5a ... ) Display unit, 5b ... Heating switch, 10 ... Controller, 11 ... Combustion control unit, 12 ... Failure notification unit, 21 ... Gas burner, 21a ... Large burner unit, 21b ... Small burner unit, 22 ... Heat exchanger, 32 ... Frame Rod 61c Gas source valve 62a First capacity switching valve 62b Second capacity switching valve

Claims (2)

A gas burner having a first burner unit and a second burner unit ;
A combustion sensor for detecting a combustion state of the gas burner;
A gas supply path;
A first gas branch path branched from the gas supply path and connected to the first burner unit;
A second gas branch path branched from the gas supply path and connected to the second burner unit;
A gas source valve provided in the gas supply path to open and close the gas supply path;
A first capacity switching valve provided in the first gas branch path to open and close the first gas branch path;
A second capacity switching valve provided in the second gas branch path to open and close the second gas branch path;
A heat exchanger heated by the gas burner;
A hot water circuit that communicates the heat exchanger with the hot water terminal;
A circulation pump for sending hot water heated by the heat exchanger to the hot water terminal via the hot water circulation path and returning hot water radiated by the hot water terminal to the heat exchanger;
The first burner unit and the second burner unit so that the temperature of warm water supplied from the warm water circulation path to the warm water terminal or the temperature of warm water returning from the warm water terminal to the warm water circulation path falls within a predetermined temperature range. A hot water circulation system including a combustion control unit that performs burner ON / OFF control for intermittently burning one or both of
The combustion control unit
In the burner ON / OFF control, the gas source valve is opened, and one or both of the first capacity switching valve and the second capacity switching valve are opened to burn the gas burner. When the gas burner is extinguished, the first gas capacity switching valve and the second capacity switching valve are controlled to be closed while the gas source valve is kept open , and the combustion sensor detects that the gas burner is extinguished. Check whether or not
When fire extinguishing of the gas burner is detected, the first capacity switching valve and the second capacity switching valve are maintained in a closed state to maintain the gas burner in a fire extinguishing state, and the fire extinguishing of the gas burner is not detected In some cases, the warm water circulation system is characterized in that the gas source valve is also controlled to be closed. The hot water circulation system according to claim 1,
In the burner ON / OFF control, the combustion control unit sets the first capacity switching valve and the second capacity switching valve while maintaining the gas source valve in an open state in a state where the gas burner is burned. A hot water circulation system comprising a failure notification unit that performs failure notification when the combustion sensor does not detect extinguishing of the gas burner when valve closing control is performed.

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