JP2019124400A - Heating system - Google Patents

Abstract

To provide a technology capable of optimizing primary energy efficiency of the whole system, in a heating system comprising two kinds of heat sources of a heat pump and a combustion machine.SOLUTION: A heating system comprises: a heat pump configured to utilize heat suctioned from outside air to heat a heat medium; a combustion machine configured to utilize heat obtained by combusting fuel to heat the heat medium; a heating machine configured to utilize the heat of the heat medium to perform heating; and a controller. The combustion machine comprises a plurality of burners. The plurality of burners each can combust the fuel. The controller is configured to, in a case where the heat medium should be heated by utilizing both of the heat pump and the combustion machine, operate only some burners of the plurality of burners in the combustion machine to heat the heat medium.SELECTED DRAWING: Figure 2

Description

  The technology disclosed herein relates to a heating system.

  In Patent Document 1, a heat pump that heats the heat medium using heat absorbed from the outside air, a combustor that heats the heat medium using the heat generated by burning the fuel, and heat of the heat medium are used. A heating system is disclosed which comprises a heating heater and a controller. When the temperature of the heat medium supplied to the heater decreases to a predetermined ignition temperature, the control device operates the burner to start heating the heat medium, and the temperature of the heat medium supplied to the heater is extinguished When the temperature rises, the operation of the burner is stopped. Furthermore, the controller raises the target heating temperature of the heat pump when operating the combustor to start heating the heat medium. Thereby, when the heat release amount in the heater decreases, the temperature of the heat medium supplied to the heater can be promptly raised to the extinguishing temperature, and heating of the heat medium by the combustion machine can be ended promptly. The heating of the heat medium by the combustion machine is suppressed to the necessary minimum.

JP 2012-13245 A

  Although the technique of Patent Document 1 considers minimizing the amount of heating by the combustion machine, it does not consider the operation content that can optimize the primary energy efficiency of the entire heating system. In a heating system provided with two types of heat sources, a heat pump and a combustor, it is required to provide a technology that can optimize the primary energy efficiency of the entire system.

  In the present specification, in a heating system provided with two types of heat sources, a heat pump and a combustor, a technique is provided that can optimize the primary energy efficiency of the entire system.

  A heating system disclosed in the present specification includes a heat pump that heats a heat medium using heat absorbed from outside air, a combustor that heats the heat medium using heat generated by burning a fuel, and the heat medium. And a controller for heating using the heat of The combustor includes a plurality of burners. Each of the plurality of burners can burn the fuel. When the heat transfer medium should be heated using both the heat pump and the combustor, the control device operates only part of the plurality of burners of the combustor to operate the heat medium. The heat medium is heated.

  As a result of earnest research by the inventors, in the case where the heat medium should be heated using both the heat pump and the combustion machine, the case where all the plurality of burners of the combustion machine are operated (hereinafter referred to as "full combustion" It has been found that the primary energy efficiency of the entire system is improved by operating only some of the plurality of burners (hereinafter sometimes referred to as "partial combustion") as compared to the case where The reason is as follows.

  Assuming that both the heat pump and the combustor should be used to heat the heat medium, if the burner is fully burned to heat the heat medium, the amount of fuel to be supplied to the combustor is minimal. Even if the power is reduced to the minimum (ie, the power is reduced to the minimum), the amount of heat that the combustor adds to the heat medium per unit time is large. Therefore, when the combustion machine is fully burned, the heat transfer medium reaches a threshold temperature (so-called extinction temperature) at which the combustion machine should be stopped in a short time. Therefore, the combustor is shut down immediately after operating for a short time. As a result, in order to maintain the heat medium at the set temperature necessary for heating, the possibility of frequent start and stop of the combustion machine is increased. Since the heat medium is heated by the heat pump even while the combustion machine is stopped (that is, all the burners are stopped), the temperature of the heat medium is prevented from sharply decreasing, and the heat medium is suppressed. It takes a relatively long period of time for the temperature of the engine to fall below the threshold temperature (so-called ignition temperature) at which the operation of the combustor should be started. That is, the period during which the combustor is not operating is extended. While the combustor is not in operation (i.e., while the combustor is not heating the heat medium), the heat medium dissipates heat while passing through the combustor. As described above, in the case where the heat medium should be heated using both the heat pump and the combustor, the heating of the heat medium by the combustor is performed even if the heat medium is heated by fully burning the combustor. If attention is focused only on the efficiency, there is no significant difference as compared with the case of heating the heat medium by partially burning the combustor.

  However, when the burner is fully burned, as described above, the burner may be frequently started and stopped. Therefore, the change in the temperature of the heat medium introduced into the heat pump becomes large, and the temperature of the heat medium introduced into the heat pump becomes unstable. That is, with the start and stop of the combustion machine frequently performed, the change of the heating amount (so-called heating width) with which the heat pump can heat the heat medium becomes large. For example, since the temperature of the heat medium introduced into the heat pump is relatively high during and immediately after the operation of the combustion machine, the heating width by the heat pump is reduced. As a result, the heating efficiency (specifically, COP (Coefficient Of Performance)) of the heat pump in the meantime becomes worse. In addition, for example, when the combustor is stopped and a long time passes, the temperature of the heat medium introduced into the heat pump becomes relatively low, so the heating width by the heat pump becomes large. The heating efficiency of the heat pump during that time is relatively good. As described above, in the case where the heat medium should be heated using both the heat pump and the combustion machine, when the combustion machine is fully burned, the heating width by the heat pump is not stable, and the heating efficiency during the entire heat pump period is averaged. Lower.

  For the above reasons, in the case where the heat medium should be heated using both the heat pump and the combustion machine, if the combustion machine is fully burned, the heating efficiency by the heat pump becomes lower, and the primary energy of the entire system Efficiency is reduced.

  On the other hand, in the case where the heat medium should be heated using both the heat pump and the combustion machine, if the heat medium is heated by partially burning the combustion machine, the heat medium can be heated per unit time. The amount of heat added to the Therefore, when partially burning the combustion machine, the temperature of the heat medium is set to the set temperature necessary for heating by adjusting the amount of fuel supplied to the combustion machine (that is, by adjusting the power of the operating burner). It becomes easy to maintain. That is, the possibility of frequent start and stop of the combustion machine is reduced. When the combustor is partially burned, the combustor can be continuously operated for a long time as compared with the case where the combustor is fully burned. However, when partially burning the combustor, some of the plurality of burners do not operate, so the heat medium dissipates heat while passing through the non-operating burner portion. Therefore, as described above, when the heat pump and the combustor are operated at the same time to heat the heat medium, when the combustor is partially burned to heat the heat medium, only the heating efficiency of the heat medium by the combustor is used. If attention is paid, the difference is not so large as compared with the case where the combustion medium is completely burned to heat the heat medium.

  However, when the combustor is partially burned, as described above, the frequency of start / stop of the combustor is low. Therefore, the change in the temperature of the heat medium introduced into the heat pump becomes small, and the temperature of the heat medium introduced into the heat pump becomes stable. Therefore, the change of the heating width by heat pump becomes small. As a result, the heating efficiency for the entire heat pump period is higher on average than when the combustor is fully burned.

  For the above reasons, in the case where the heat medium should be heated using both the heat pump and the combustion machine, if the combustion machine is partially burned, the heating efficiency by the heat pump becomes high, and the primary energy of the entire system Efficiency is high.

  According to the above configuration, when the heat transfer medium is to be heated using both the heat pump and the combustor, the controller operates only a part of the plurality of burners of the combustor to operate the heat. The medium is heated. Thereby, in the case where the heat medium should be heated using both the heat pump and the combustor, the primary energy of the whole system is compared with the case where the heat medium is heated by operating all the burners of the combustor. Efficiency can be increased. Therefore, according to the above configuration, in a heating system provided with two types of heat sources of a heat pump and a combustor, the primary energy efficiency of the entire system can be optimized.

  When the heat medium is to be heated using the burner without using the heat pump, the control device operates all the plurality of burners of the burner to heat the heat medium. You may do it.

  As a result of earnest research by the inventors, when the heat medium should be heated using a combustion machine without using a heat pump (for example, when the heat pump is used for heating applications other than heating), all the combustion machines are used. It has also been found that the combustion efficiency is higher than the partial combustion of the combustor. That is, in the case where the heat medium is heated using the combustor without using the heat pump, when the combustor is partially burned, the heat medium acts on the non-operating burner portion of the plurality of burners of the combustor. During the passage, heat is released, and the heating efficiency of the heat medium is reduced. In particular, when the fan in the combustion machine operates as in the case of full combustion, the amount of heat release at the non-operating burner portion becomes even larger. On the other hand, when the combustor is completely burned, the above-described heat radiation is not performed, and the heat loss is reduced. However, since the amount of heat to be added to the heat medium per unit time increases, the possibility of frequent start / stop of the combustion machine is high in order to maintain the heat medium at the set temperature required for heating. However, since the heat medium is not heated by the heat pump while the combustion machine is stopped, the temperature of the heat medium falls below the ignition temperature relatively early after the combustion machine is stopped, and the combustion machine is operating. The short period (ie, the period during which the combustor does not heat the heat medium) is short. Therefore, in the case where the heat medium should be heated using a combustor without using a heat pump, full combustion of the combustor is higher in heating efficiency than partial combustion of the combustor. According to the above configuration, even when the heat medium is to be heated using a combustor without using a heat pump, the primary energy efficiency of the entire system can be optimized.

The figure which shows typically operation | movement of the hot-water supply heating system 2 at the time of a thermal storage driving | operation and the hot-water supply driving | operation. The figure which shows typically operation | movement of the hot-water supply heating system 2 at the time of combined heating driving | operation. The flowchart which shows heat pump temperature control control. The flowchart which shows burner temperature regulation control. The graph showing the temperature change of the detection temperature of the thermistor 78 in each case at the time of making the burner heating apparatus 82 full burn and the case of carrying out partial burning at the time of combined heating operation. The graph showing the relation between the combustion load of burner heating device 82 at the time of combined heating operation, and the average combustion efficiency of burner heating device 82. The graph showing the relation between the combustion load of burner heating device 82 at the time of combined heating operation, and COP of heat pump 50. The graph showing the relation between the combustion load of burner heating device 82 at the time of combined heating operation, and the primary energy efficiency of the whole system. The figure which shows typically operation | movement of the hot-water supply heating system 2 at the time of independent heating operation. The graph showing the relation between the combustion load of burner heating device 82 at the time of sole heating operation, and the average combustion efficiency of burner heating device 82.

(Example)
As shown in FIG. 1, the hot water supply and heating system 2 according to the present embodiment includes a hot water supply system 104, a heat pump system 106, a heating system 108, and a control device 100.

  The heat pump system 106 includes a heat pump 50. The heat pump 50 includes a refrigerant circulation path 52 for circulating a refrigerant (for example, fluorocarbon gas R410A etc.), a heat exchanger (evaporator) 54, a fan 56, a compressor 62, and a three-fluid heat exchanger (a condenser ) And an expansion valve 60. The heat exchanger 54, the compressor 62, the three-fluid heat exchanger 58, and the expansion valve 60 are installed in the refrigerant circuit 52. By operating the heat pump 50 having such a configuration, a high temperature / high pressure refrigerant can be fed into the refrigerant circulation path 52 passing through the three-fluid heat exchanger 58.

  The hot water supply system 104 includes a tank 10, a tank water circulation passage 20, a tap water introduction passage 24, a supply passage 36, and a burner heating device 81.

  The tank 10 stores the hot water heated by the heat pump 50. The tank 10 is of a closed type and is covered on the outside by a heat insulating material. Water is stored in the tank 10 to full water. In the tank 10, thermistors 12, 14, 16, 18 are attached at substantially equal intervals in the height direction of the tank 10. Each thermistor 12, 14, 16, 18 measures the temperature of the water at its mounting position.

  The tank water circulation passage 20 has an upstream end connected to the lower portion of the tank 10 and a downstream end connected to the upper portion of the tank 10. A circulation pump 22 is interposed in the tank water circulation passage 20. The circulation pump 22 pumps the water in the tank water circulation passage 20 from the upstream side to the downstream side. Further, as described above, the tank water circulation passage 20 passes through the three-fluid heat exchanger 58. Therefore, when the heat pump 50 is operated, the water in the tank water circulation passage 20 is heated by the three-fluid heat exchanger 58. Therefore, when the circulation pump 22 and the heat pump 50 are operated, the water in the lower part of the tank 10 is sent to the three-fluid heat exchanger 58 to be heated, and the heated water is returned to the upper part of the tank 10. The tank water circulation passage 20 is a water passage for storing heat in the tank 10.

  An upstream end of the tap water introduction passage 24 is connected to a tap water supply source 32. The downstream side of the tap water introduction passage 24 is branched into a first introduction passage 24 a and a second introduction passage 24 b. The downstream end of the first introduction passage 24 a is connected to the lower portion of the tank 10. The downstream end of the second introduction passage 24 b is connected to the middle of the supply passage 36. At the connection portion, a mixing valve 36a is disposed for adjusting the ratio of the flow rate of water flowing through the first introduction passage 24a (that is, the flow rate of water flowing from the tank 10 to the supply passage 36) and the flow rate of water flowing through the second introduction passage 24b. It is done. A check valve 26 is interposed in the first introduction passage 24a. A check valve 28 and a water amount sensor 30 are interposed in the second introduction passage 24b. The water amount sensor 30 detects the flow rate of the tap water flowing in the second introduction passage 24b.

  The supply path 36 is connected to the upper end of the tank 10 at its upstream end. As described above, in the middle of the supply passage 36, the second introduction passage 24b of the tap water introduction passage 24 is connected. A water amount sensor 34 is interposed in the supply passage 36 on the upstream side of the connection with the second introduction passage 24 b. The water amount sensor 34 detects the flow rate of water flowing from the tank 10 to the supply passage 36. A burner heating device 81 is interposed in the supply passage 36 downstream of the connection with the second introduction passage 24 b. The burner heating device 81 includes a burner 81a capable of burning a gas. The burner heating device 81 heats the water in the supply passage 36 by operating the burner 81 a to burn the gas. The downstream end of the supply passage 36 is connected to the hot water supply tap 38. The supply passage 36 is provided with a bypass passage 36 b which is a flow passage for bypassing the burner heating device 81. Further, a bypass control valve 36c for adjusting the opening degree of the bypass passage 36b is interposed in the bypass passage 36b.

  The heating system 108 includes a cistern 70, a heating heat medium circulation path 71, a burner heating device 82, and a heater 76. The heating heat medium circulation passage 71 includes a heating forward passage 72, a heating return passage 84, a control valve 90, a heat recovery passage 88, a bypass passage 94, and a circulation passage 96. The heating heat medium circulation path 71 is a flow path for circulating the heat medium (specifically, water or antifreeze liquid) in the cistern 70. The heat medium in the heating heat medium circulation passage 71 is heated by the burner heating device 82 and the three-fluid heat exchanger 58.

  The cistern 70 is a container whose top is open and stores therein a heat medium for heating (that is, water or antifreeze liquid). The downstream end of the circulation flow passage 96 and the upstream end of the heating forward passage 72 are connected to the cistern 70. The heat medium flows from the circulation channel 96 into the cistern 70. The heat medium in the cistern 70 is introduced into the heating route 72.

  The heating forward path 72 is connected at its upstream end to the cistern 70 and at its downstream end to the entrance of the heater 76. A circulation pump 74 is interposed in the heating route 72. The circulation pump 74 is a pump for delivering the heat medium in the heating forward passage 72 to the downstream side. A burner heating device 82 is interposed in the heating path 72 upstream of the heater 76. The burner heating device 82 heats the heat medium in the heating forward path 72. In the present embodiment, the burner heating device 82 includes four burners 82a to 82d. Each of the burners 82a to 82d can burn a gas. The burner heating device 82 heats the heat medium in the outward heating path 72 by operating a part or all of the burners 82 a to 82 d to burn the gas. The operation of the burner heating device 82 is illustrated in FIGS. 2 and 9. In the example of FIG. 2, only one burner 82a is operating, and in the example of FIG. 9, all the burners 82a to 82d are operating. The burner heating device 82 also includes a fan (not shown) that operates to blow air when the burners (one burner 82a or all the burners 82a to 82d) operate. The burner heating device 82 has a higher ability to heat the heat medium than the heat pump 50. In other words, the burner heating device 82 has a larger heating amount per unit time than the heat pump 50. The heat medium heated by the burner heating device 82 is supplied to the heater 76. Further, on the downstream side of the burner heating device 82 of the forward heating path 72, a thermistor 78 is interposed. The thermistor 78 measures the temperature of the heat medium in the heating path 72 after passing through the burner heating device 82.

  The heater 76 is a terminal that heats the living room using the heat of the heat medium supplied from the outward heating path 72. When used for heating, the heat medium supplied from the heating forward path 72 loses heat and becomes relatively low temperature. The relatively low temperature heat medium used for heating is introduced into the heating return path 84.

  The heating return path 84 is connected at its upstream end to the return port of the heater 76 and at its downstream end to the upstream end of the bypass path 94 and the upstream end of the heat recovery path 88. A thermistor 86 is interposed in the heating return path 84. Thermistor 86 measures the temperature of the heat medium in the heating return path 84 (that is, the temperature of the heat medium fed to the three-fluid heat exchanger 58).

  The heat recovery passage 88 has an upstream end connected to the upstream end of the bypass passage 94 and the downstream end of the heating return passage 84, and a downstream end connected to the downstream end of the bypass passage 94 and the upstream end of the circulation passage 96. The heat recovery passage 88 passes through the three-fluid heat exchanger 58. Therefore, when the heat pump 50 is operated, the heat medium in the heat recovery passage 88 is heated by the three-fluid heat exchanger 58. A thermistor 92 is interposed downstream of the three-fluid heat exchanger 58 in the heat recovery passage 88. The thermistor 92 measures the temperature of the heat medium in the heat recovery passage 88 after passing through the three-fluid heat exchanger 58.

  The bypass passage 94 has an upstream end connected to the downstream end of the heating return passage 84 and the upstream end of the heat recovery passage 88, and a downstream end connected to the downstream end of the heat recovery passage 88 and the upstream end of the circulation passage 96. That is, the bypass passage 94 bypasses the upstream side and the downstream side of the three-fluid heat exchanger 58.

  The control valve 90 is attached to the connection between the downstream end of the heating return passage 84, the upstream end of the heat recovery passage 88, and the upstream end of the bypass passage 94. The adjusting valve 90 changes the opening degree thereof so that the flow rate of the heat medium passing through the heat recovery passage 88 (the flow rate of the heat medium passing through the three-fluid heat exchanger 58) and the heat medium passing through the bypass passage 94 Flow rate and ratio can be changed. For example, a three-way valve is used for the control valve 90 of the present embodiment.

  The circulation channel 96 has an upstream end connected to the downstream end of the heat recovery channel 88 and a downstream end of the bypass channel 94, and a downstream end connected to the cistern 70. A thermistor 98 is interposed in the circulation channel 96. The thermistor 98 measures the temperature of the heat medium in the circulation flow path 96.

  The control device 100 is electrically connected to the hot water supply system 104, the heat pump system 106, and the heating system 108, and controls the operation of each component.

(Operation of hot water supply heating system)
Next, the operation of the hot water supply heating system 2 of the present embodiment will be described. The hot water supply and heating system 2 can execute each operation of a heat storage operation, a hot water supply operation, a combined heating operation, and a single heating operation. Each operation will be described below.

(Heat storage operation)
The heat storage operation is an operation of heating the water in the tank 10 by the heat generated by the heat pump 50. Solid arrows in FIG. 1 indicate the flow of the refrigerant of the heat pump 50 and the flow of the water of the tank 10 during the heat storage operation. When execution of the heat storage operation is instructed by the control device 100, the heat pump 50 starts operation and the circulation pump 22 rotates.

  Due to the operation of the heat pump 50, the refrigerant in the refrigerant circuit 52 passing through the three-fluid heat exchanger 58 turns into a high-temperature high-pressure gaseous state. In addition, when the circulation pump 22 rotates, the water in the tank 10 circulates in the tank water circulation passage 20. That is, water present in the lower part of the tank 10 is introduced into the tank water circulation passage 20, and when the introduced water passes through the three-fluid heat exchanger 58, it is heated by the heat of the refrigerant in the refrigerant circulation passage 52, The heated water is returned to the top of the tank 10. As a result, high temperature water is stored in the tank 10. In the upper part of the tank 10, a layer of high temperature water is formed, and in the lower part, a layer of low temperature water is formed.

(Hot water supply operation)
The hot water supply operation is an operation for supplying the water in the tank 10 to the hot water supply tap 38. The broken arrows in FIG. 1 indicate the flow of water in the tank 10 during the hot water supply operation. The hot water supply operation can also be performed during the above-described heat storage operation. When the hot water tap 38 is opened, the control device 100 opens the mixing valve 36a. Then, the tap water flows into the lower part of the tank 10 from the tap water introduction passage 24 (first introduction passage 24 a) by the water pressure from the tap water supply source 32. At the same time, the hot water at the top of the tank 10 is supplied to the hot water tap 38 through the supply passage 36.

  If the temperature of the water supplied from the tank 10 to the supply path 36 (ie, the detected temperature of the thermistor 12) is higher than the hot water supply set temperature, the control device 100 adjusts the mixing valve 36a to set the second introduction path. The tap water is introduced to the supply path 36 from 24b. Therefore, the water supplied from the tank 10 and the tap water supplied from the second introduction passage 24 b are mixed in the supply passage 36. Control device 100 adjusts the opening degree ratio of mixing valve 36 a such that the temperature of the water supplied to hot water supply plug 38 matches the hot water supply set temperature. On the other hand, control device 100 operates burner heating device 81 when the temperature of water supplied from tank 10 to supply path 36 is lower than the hot water supply set temperature. Accordingly, the water passing through the supply passage 36 is heated by the burner heating device 81. The heated water is mixed with the water from the bypass passage 36 b whose opening degree is adjusted by the bypass control valve 36 c, and is supplied to the hot water tap 38. Control device 100 controls the output of burner heating device 81 such that the temperature of the water supplied to hot water supply plug 38 matches the hot water supply set temperature.

(Combined heating operation)
In the combined heating operation, both the heat pump 50 and the burner heating device 82 are operated to heat the heat medium in the heating heat medium circulation passage 71, and the heat of the heated heat medium is dissipated by the heater 76. It is a heating operation to heat the The situation where the combined heating operation should be performed is, for example, a heat source for heating both the heat pump 50 and the burner heating device 82 as in the case where the heating operation should be performed while the heat storage operation and the hot water supply operation are not performed. It is the situation where execution of heating operation is instructed when it is possible to use. Solid arrows in FIG. 2 indicate the flow of the refrigerant of the heat pump 50 during the combined heating operation and the flow of the heat medium in the heating heat medium circulation passage 71.

  When the user instructs execution of the heating operation, first, the control device 100 adjusts the opening degree of the adjustment valve 90 according to the heating load in the heater 76. Thus, the heat medium in the cistern 70 passes from the cistern 70 through the heating forward path 72, the heater 76, the heating return path 84, the heat recovery path 88, and the circulation path 96 in this order to return to the cistern 70. Are formed (see FIG. 2). Further, depending on the opening degree of the adjustment valve 90, a path through which a part of the heat medium flowing in the heat recovery passage 88 passes through the bypass passage 94 and is introduced into the circulation passage 96 is also formed (not shown).

  Next, the control device 100 sets a heating set temperature, which is the temperature of the heat medium to be supplied to the heater 76, based on the operating temperature set by the user. The control device 100 calculates and sets the heating set temperature using a predetermined calculation formula. Next, the control device 100 operates the circulation pump 74 at a predetermined rotational speed. By operating the circulation pump 74, the heat medium circulates in the above path.

  Next, the control device 100 starts the heat pump temperature adjustment control of FIG. 3 and the burner temperature adjustment control of FIG. 4. The contents of the heat pump temperature control and the burner temperature control will be described in detail later. After starting the heat pump temperature adjustment control and the burner temperature adjustment control, the control device 100 continues to execute the heat pump temperature adjustment control and the burner temperature adjustment control until the end of the heating operation is instructed by the user. .

  The heat pump temperature control will be described with reference to FIG. The heat pump temperature control is a control that the control device 100 executes in order to heat the heat medium to a predetermined target hot water temperature by the heat pump 50. The target tapping temperature is the target temperature of the heat medium after being heated by the three-fluid heat exchanger 58. As shown in FIG. 3, when the heat pump temperature adjustment control is started, first, in S10, the control device 100 sets the heating set temperature, the bypass ratio of the adjustment valve 90 (of the heat medium flowing in the heating heat medium circulation passage 71). The target outlet hot water temperature is calculated based on the ratio of the heat medium flowing through the bypass passage 94) and the detected temperature of the thermistor 86 (the temperature of the heat medium fed to the three-fluid heat exchanger 58).

  Next, in S12, the control device 100 causes the detected temperature of the thermistor 92 (the temperature of the heat medium sent from the three-fluid heat exchanger 58) to be lower than the operation start temperature higher by a predetermined temperature α1 (for example 1 ° C.) than the target outlet temperature. Monitor that. The value of α1 may be changed according to the target tapping temperature. In another example, the operation start temperature may be lower than the target tapping temperature by the predetermined temperature α1. When the temperature detected by the thermistor 92 falls below the above-described operation start temperature, the control device 100 determines YES in S12, and proceeds to S14.

  In S14, the control device 100 starts the operation of the heat pump 50. By operating the heat pump 50, the heat medium passing through the heat recovery passage 88 is heated by the heat of the refrigerant in the refrigerant circulation passage 52 in the three-fluid heat exchanger 58.

  Next, in S16, the control device 100 monitors that the detection temperature of the thermistor 92 becomes equal to or higher than the stop temperature higher by a predetermined temperature α2 (for example, 15 ° C.) than the target outlet hot water temperature. If the temperature detected by the thermistor 86 is equal to or higher than the stop temperature, the control device 100 determines YES in S16, and proceeds to S18. If the temperature detected by the thermistor 92 is equal to or higher than the stop temperature, the temperature of the refrigerant in the refrigerant circuit 52 passing through the three-fluid heat exchanger 58 and the temperature in the heat recovery passage 88 passing through the three-fluid heat exchanger 58. The difference in temperature of the heat medium decreases, and the heating efficiency by the heat pump 50 decreases.

  In S18, the control device 100 stops the heat pump 50. Thus, the heat medium passing through the heat recovery passage 88 is not heated by the heat of the refrigerant in the refrigerant circulation passage 52 in the three-fluid heat exchanger 58.

  When S18 ends, the control device 100 returns to S10. As described above, the control device 100 repeatedly executes the processes of S10 to S18 until the user instructs to end the heating operation.

  Next, burner temperature control will be described with reference to FIG. The burner temperature adjustment control is control that the control device 100 executes to operate the burner heating device 82 to bring the temperature of the heat medium supplied to the heater 76 to the heating set temperature.

  First, in S30, the control device 100 determines that the detected temperature of the thermistor 78 (that is, the temperature of water supplied to the heater 76) falls below the ignition temperature lower by a predetermined temperature β (for example, 5 ° C.) than the heating set temperature. Monitor The value of β may be changed according to the heating set temperature. If the temperature detected by the thermistor 78 is lower than the ignition temperature, the controller 100 determines YES in S30, and proceeds to S32.

  In S32, the control device 100 starts the operation of the burner heating device 82. The contents of S32 differ depending on whether the hot water supply heating system 2 is performing the combined heating operation or the single heating operation (described later). In this case, in the hot water supply and heating system 2, the combined heating operation is performed (that is, the control device 100 is also executing the heat pump temperature adjustment control (FIG. 3) in parallel). Therefore, in S32, the control device 100 burns the gas using only some of the burners 82a to 82d of the burner heating device 82 (for example, the burner 82a). Such operation of the burner heating device 82 may be hereinafter referred to as "partial combustion". The heat medium is heated by the burner heating device 82 as the burner heating device 82 starts partial combustion.

  When the operation of the burner heating device 82 is started in S32, the control device 100 sets the flow rate of the gas supplied to the burner heating device 82 (in this case, the burner 82a) so that the detected temperature of the thermistor 78 becomes stable at the heating set temperature. adjust. Specifically, the control device 100 reduces the flow rate of gas when the detected temperature of the thermistor 78 exceeds the heating set temperature, and increases the flow rate of the gas when the detected temperature of the thermistor 78 falls below the heating set temperature. be able to. The power of the burner 82a increases or decreases with the increase or decrease of the gas flow rate.

  Next, in S34, the control device 100 monitors that the detected temperature of the thermistor 78 becomes equal to or higher than the extinguishing temperature higher by a predetermined temperature γ (for example, 5 ° C.) than the heating set temperature. The value of γ may be changed according to the heating set temperature. If the temperature detected by the thermistor 78 is equal to or higher than the extinguishing temperature, the control device 100 determines YES in S34, and proceeds to S36.

  In S36, the control device 100 stops the burner heating device 82. That is, the control device 100 extinguishes the burning burner 82a. As a result, the heat medium is not heated by the burner heating device 82.

  When S36 ends, the control device 100 returns to S30. As described above, the control device 100 repeatedly executes each process of S30 to S36 until the user instructs to end the heating operation.

  The heat pump temperature control (FIG. 3) and the burner temperature control (FIG. 4) have been described above. As described above, when the user instructs to finish the heating operation while the heat pump temperature control and the burner temperature control are being executed, the control device 100 operates the heat pump 50, the burner heating device 82, , All the circulation pumps 74 are stopped. In that case, the combined heating operation ends.

  As described above, in the combined heating operation, when operating the burner heating device 82 (see S32 in FIG. 4), the control device 100 performs partial combustion in which only the burner 82a is operated. When operating the burner heating device 82 in the combined heating operation, the partial combustion as described above is more effective than the case of performing the “full combustion” in which all the burners 82 a to 82 d are operated. Primary energy efficiency is high. The reason will be described below.

  FIG. 5 shows the thermistor 78 in each case where the burner heating device 82 is completely burned (see (a)) and partially burned as described above (see (b)) during the combined heating operation. It is a graph showing the temperature change of detection temperature. In the example of FIG. 5, the heating set temperature is 40 ° C., the ignition temperature is 35 ° C., and the extinguishing temperature is 45 ° C.

  As shown in FIG. 5A, when the burner heating device 82 is fully burned, the burner heating device 82 operates once even in a state where the flow rate of gas supplied to each of the burners 82a to 82d is reduced to the minimum value. Then, the amount of heat added to the water in the heating forward path 72 per unit time increases (for example, at a minimum of 10000 kcal / h). Therefore, as shown to (a) of FIG. 5, the detection temperature of the thermistor 78 reaches the extinction temperature (45 degreeC) in a short time. Therefore, the burner heating device 82 is turned off soon after operating for a short time. Therefore, in order to keep the heat medium at the heating set temperature, the burner heating device 82 is easily switched on and off frequently.

  On the other hand, as shown in (b) in FIG. 5, when the burner heating device 82 is partially burned, the gas is burned only by the burner 82a. Therefore, when the flow rate of the gas is narrowed to the minimum value, The amount of heat applied to the water in the forward heating path 72 can be reduced (for example, at a minimum of 2500 kcal / h). Therefore, as shown in FIG. 5B, by adjusting the flow rate of the gas supplied to the burner heating device 82, it becomes easy to maintain the detection temperature of the thermistor 78 at a value near the heating set temperature. That is, in order to maintain the temperature of the water in the heating forward path 72 at a value close to the heating set temperature, the possibility of frequent start / stop of the burner heating device 82 is low. When the burner heating device 82 is partially burned, the burner heating device 82 can be continuously operated for a long time as compared with the case where the burner heating device 82 is fully burned.

  6 shows the relationship between the combustion load of the burner heating device 82 and the average combustion efficiency of the burner heating device 82 during the combined heating operation. Here, the “average combustion efficiency” indicates a value obtained by averaging the combustion efficiency during the operation of the burner heating device 82 and the combustion efficiency during the period when the burner heating device 82 is stopped. E1 in FIG. 6 represents the relationship when the burner heating device 82 is fully burned, and E2 represents the relationship when the burner heating device 82 is partially burned. As shown in E2, when the burner heating device 82 is partially burned, the combustion load is 7 kW at the maximum. The same applies to FIGS. 7, 8 and 10 below. As E1 and E2 indicate, there is no significant difference in the average combustion efficiency between the case where the burner heating device 82 is fully burned and the case where it is partially burned.

  As described above, when the burner heating device 82 is fully burned in the combined heating operation, the possibility that the burner heating device 82 is frequently turned on and off increases (see (a) in FIG. 5). Since the heat medium in the heat medium circulation path 71 for heating is heated by the heat pump 50 while the burner heating device 82 is stopped (that is, the operation of all the burners 82a to 82d is stopped), It is suppressed that the temperature of the medium drops rapidly, and it takes a relatively long time before the temperature of the heat medium drops to the ignition temperature of the burner heating device 82. That is, the period during which the burner heating device 82 is not operating is extended. While the burner heating device 82 is not in operation, the heat transfer medium is in natural convection heat exchange with air while passing through the burner heating device 82 (ie, with the air of the burner heating device 82 while the fan is stopped). Heat exchange causes heat dissipation. Note that “heat release” referred to here is the temperature before the temperature of the heat medium introduced into the burner heating device 82 is detected temperature of the thermistor 78 (that is, the heat before introduced into the heater 76 after passing through the burner heating device 82 It means heat dissipation in a period higher than the temperature of the medium). As described above, when the combined heating operation is performed, the heat medium is also heated by the heat pump 50 while the burner heating device 82 is stopped, but the burner heating device 82 is used in the calculation of the average combustion efficiency in FIG. The heat quantity (heat release amount) radiated by the burner heating device 82 while the engine is stopped is considered in consideration of the heat release amount resulting from the burner heating device 82.

  Further, as described above, when the burner heating device 82 is partially burned during the combined heating operation, the possibility of frequent start / stop of the burner heating device 82 becomes low, and the burner heating device 82 continues to operate for a long time (See FIG. 5 (b)). However, when the burner heating device 82 is partially burned, forced convection heat exchange with air (that is, the fan of the burner heating device 82 operates) while the heat medium passes through the non-operating burners 82 b to 82 d. Heat is released due to heat exchange with air.

  Therefore, as described above, if focusing only on the average heating efficiency by the burner heating device 82, there is a so large difference between the case where the burner heating device 82 is fully burned and the case where it is partially burned during the combined heating operation. It disappears (see E1 and E2 in FIG. 6).

  However, a large difference occurs in the heating efficiency of the heat pump 50 between the case where the burner heating device 82 is fully burned and the case where the burner heating device 82 is partially burned in the combined heating operation. FIG. 7 shows the relationship between the combustion load of the burner heating device 82 and the COP of the heat pump 50 during the combined heating operation. E11 in FIG. 7 represents the relationship when the burner heating device 82 is fully burned, and E12 represents the relationship when the burner heating device 82 is partially burned. As E11 and E12 indicate, the COP of the heat pump 50 for partially burning the burner heating device 82 is higher than the COP of the heat pump 50 for partially burning.

  As described above, when the burner heating device 82 is fully burned in the combined heating operation, the burner heating device 82 is frequently turned on and off (see (a) of FIG. 5). Therefore, the temperature change of the heat medium introduced into the heat pump 50 becomes large, and the temperature of the heat medium introduced into the heat pump 50 becomes unstable. That is, with the start and stop of the burner heating device 82 frequently performed, the change of the heating amount (so-called heating width) with which the heat pump 50 can heat the heat medium becomes large. For example, since the temperature of the heat medium introduced into the heat pump 50 becomes relatively high during and immediately after the operation of the burner heating device 82, the heating width by the heat pump 50 is reduced. As a result, the COP of the heat pump during that time gets worse. Further, for example, when the burner heating device 82 is stopped and a long period of time passes, the temperature of the heat medium introduced into the heat pump 50 becomes relatively low, so the heating width by the heat pump 50 becomes large. The COP of the heat pump 50 in the meantime becomes relatively good. As described above, when the burner heating device 82 is fully burned during the combined heating operation, the heating width by the heat pump 50 is not stable, and the COP of the heat pump 50 becomes low on average (see E11 in FIG. 7).

  On the other hand, when the burner heating device 82 is partially burned during the combined heating operation, as described above, the frequency of start / stop of the burner heating device 82 is low (see (b) in FIG. 5). Therefore, the change in the temperature of the heat medium introduced into the heat pump 50 becomes small, and the temperature of the heat medium introduced into the heat pump 50 becomes stable. Therefore, the change of the heating width by heat pump 50 becomes small. As a result, the COP of the heat pump 50 is higher on average than in the case of full combustion (see E12 in FIG. 7).

  Due to this, as shown in FIG. 8, when the burner heating device 82 is partially burned during the combined heating operation, the primary energy efficiency of the entire system is higher than when the entire combustion is performed. FIG. 8 shows the relationship between the combustion load of the burner heating device 82 during the combined heating operation and the primary energy efficiency of the entire hot water heating system 2. E21 in FIG. 8 represents the relationship when the burner heating device 82 is fully burned, and E22 represents the relationship when the burner heating device 82 is partially burned. As E21 and E22 indicate, the primary energy efficiency when partially burning the burner heating device 82 is higher than the primary energy efficiency when completely burning.

(Single heating operation)
The independent heating operation is a heating operation in which the heat medium in the heating heat medium circulation passage 71 is heated using only the burner heating device 82 as a heat source, and the room is heated by the heater 76 using the heat of the heated heat medium. is there. In a situation where a single heating operation is to be performed, it is necessary to use the heat pump 50 as a heat source for heating the hot water in the tank 10, for example, as in the case where the heating operation should be performed while the thermal storage operation is being performed. There is a situation where the execution of the heating operation is instructed when only the burner heating device 82 is available as a heat source for heating. The solid line arrows in FIG. 9 indicate the flow of the refrigerant of the heat pump 50 during the combined heating operation and the flow of the heat medium in the heating heat medium circulation passage 71.

  Also in this case, when execution of the heating operation is instructed by the user, first, the control device 100 adjusts the opening degree of the adjustment valve 90, and all the heat medium flowing through the heating return passage 84 passes through the bypass passage 94. (Bypassing the heat recovery passage 88) to be introduced into the circulation passage 96. That is, a path bypassing the three-fluid heat exchanger 58 is formed. As a result, the heat medium in the cistern 70 passes from the cistern 70 through the heating forward path 72, the heater 76, the heating return path 84, the bypass path 94, and the circulation path 96 in this order to return to the cistern 70. Formed (see FIG. 9).

  Next, the control device 100 sets a heating set temperature, which is the temperature of the heat medium to be supplied to the heater 76, based on the operating temperature set by the user. Next, the control device 100 operates the circulation pump 74 at a predetermined number of rotations to circulate the heat medium in the above path.

  Next, the controller 100 starts burner temperature control (see FIG. 4). In this case, since the heat pump 50 is already operating for another use (for example, heating of water in the tank 10), the control device 100 does not perform the heat pump temperature control (see FIG. 3). After starting the burner temperature adjustment control, the control device 100 continuously executes the burner temperature adjustment control until the user instructs to end the heating operation.

  The contents of the burner temperature adjustment control (FIG. 4) in the case of the single heating operation are basically the same as the burner temperature adjustment control in the case of the combined heating operation. However, in the case of the single heating operation, in S32, the control device 100 burns the gas (that is, burns all) using all the burners 82a to 82d of the burner heating device 82. The heat medium is heated by the burner heating device 82 as the burner heating device 82 starts the full combustion. Also in the case of the single heating operation, as in the case of the combined heating operation, the control device 100 adjusts the flow rate of the gas supplied to the burner heating device 82 (in this case, the burners 82a to 82d) as necessary. The thermal power of the burners 82a to 82d increases or decreases with the increase or decrease of the gas flow rate.

  During execution of the burner temperature adjustment control, when the user instructs the end of the heating operation, the control device 100 stops all the burner heating device 82 and the circulation pump 74 currently in operation. In that case, the single heating operation ends.

  As described above, in the single heating operation, when operating the burner heating device 82 (see S32 in FIG. 4), the control device 100 performs full combustion in which all the burners 82a to 82d are operated. When operating the burner heating device 82 in the single heating operation, unlike in the case of the combined heating operation, performing the full combustion has higher primary energy efficiency of the entire system than performing the partial combustion. The reason will be described below.

  FIG. 10 shows the relationship between the combustion load of the burner heating device 82 and the average combustion efficiency of the burner heating device 82 in the single heating operation. In FIG. 10, E31 represents the relationship when the burner heating device 82 is fully burned, and E32 represents the relationship when the burner heating device 82 is partially burned. As E31 and E32 indicate, regardless of the magnitude of the combustion load, the average combustion efficiency in the case where the burner heating device 82 is fully burned is higher than the average combustion efficiency in the case of the partial combustion.

  In the case of the single heating operation, the heat pump 50 is already used for applications other than heating, and only the burner heating device 82 is used as a heat source for heating. At this time, if the burner heating device 82 is partially burned, heat is released while the heat medium passes through the non-operating burners 82b to 82d of the burners 82a to 82d of the burner heating device 82. The heating efficiency of the heat medium is reduced (see E32 in FIG. 10). In particular, when the fan (not shown) in the burner heating device 82 operates as in the case of the full combustion, the amount of heat radiation at the non-operating burners 82 b to 82 d becomes even larger. On the other hand, when the burner heating device 82 is completely burned, the above-described heat radiation is not performed, and the heat loss is reduced. However, since the amount of heat added to the heat medium per unit time by the burner heating device 82 is increased, the possibility of frequent start / stop of the burner heating device 82 is high to maintain the heat medium at the heating set temperature. . However, since the heat medium is not heated by the heat pump 50 while the burner heating device 82 is stopped, the temperature of the heat medium falls below the ignition temperature relatively early after the burner heating device 82 is stopped ( The period in which the burner heating device 82 is not in operation (that is, the period in which the burner heating device 82 is not heating the heat medium) may be short, in the case of YES in S30 of FIG. 4. Therefore, in the single heating operation, the heating efficiency is higher when the burner heating device 82 is fully burned than when the burner heating device 82 is partially burned. Therefore, in the case of the single heating operation, the primary energy efficiency of the entire system is also higher due to the higher heating efficiency in the case where the burner heating device 82 is fully burned compared to the case in which the burner heating device 82 is partially burned.

  The contents of each operation (heat storage operation, hot water supply operation, combined heating operation, single heating operation) of the hot water supply and heating system 2 have been described above. In addition, when heat pump 50 is utilized for uses other than heating (for example, thermal storage driving | operation is started) during execution of combined heating operation, the control apparatus 100 carries out the operation content from combined heating operation to single heating operation. Switch to At that time, the control device 100 ends the heat pump temperature control (FIG. 3). Then, after switching the burner heating device 82 in operation from partial combustion to full combustion, the control device 100 continues the burner temperature control (FIG. 4).

  On the other hand, when the heat pump 50 shifts to a state where the heat pump 50 can be used as a heat source for heating (for example, the heat storage operation being performed is ended) during execution of the single heating operation, the control device 100 Switch from single heating operation to combined heating operation. At that time, the control device 100 starts heat pump temperature control (FIG. 3). Then, after the burner heating device 82 in operation is switched from the full combustion to the partial combustion, the control device 100 continues the burner temperature control (FIG. 4).

  The configuration and operation of the hot water supply heating system 2 of the present embodiment have been described above. As described above, in the present embodiment, when the combined heating operation is performed, the control device 100 partially burns the burner heating device 82 (S32 in FIG. 4). As a result, in the case where the heat medium should be heated using both the heat pump 50 and the burner heating device 82, the primary energy efficiency of the entire system can be increased as compared to the case where the burner heating device 82 is completely burned. Therefore, according to the present embodiment, the primary energy efficiency of the entire system can be optimized in the hot water supply heating system 2 provided with the two heat sources of the heat pump 50 and the burner heating device 82.

  Further, in the present embodiment, when the single heating operation is performed, the control device 100 causes the burner heating device 82 to burn completely (S32 in FIG. 4). As described above, when the single heating operation is performed, the combustion efficiency is higher when the burner heating device 82 is fully burned than when the partial heating is performed. According to the present embodiment, even when the heat medium is to be heated using the burner heating device 82 without using the heat pump 50, the primary energy efficiency of the entire system can be optimized.

  The correspondence between the present embodiment and the claims will be described. The burner heating device 82 is an example of the “combustor”. The case where the combined heating operation is performed is an example of "the case where the heat medium should be heated using both the heat pump and the combustor". The case where the single heating operation is performed is an example of “the case where the heat medium should be heated using a combustion machine without using a heat pump”.

  As mentioned above, although an Example was described in detail, these are only examples and do not limit the range of a claim. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above.

(Modification 1) In the above embodiment, when the burner heating device 82 is partially burned, only one burner 82a is operated. However, the number of burners operated when the burner heating device 82 is partially burned is not limited to one, and may be two or three. Generally speaking, only a part of the plurality of burners of the combustor may be operated to heat the heat medium.

(Modification 2) In the above embodiment, the burner heating device 82 includes four burners 82a to 82d. However, the number of burners provided in the burner heating device 82 is not limited to four, and may be another number (for example, three, five or more, etc.). Generally speaking, the combustor may have a plurality of burners.

(Modification 3) In the above embodiment, in the burner temperature adjustment control (FIG. 4), the control device 100 sets the detected temperature of the thermistor 78 (that is, the temperature of the heat medium supplied to the heater 76) as a reference. The start and stop of the operation of the burner heating device 82 are switched. However, the control device 100 may switch the start and stop of the operation of the burner heating device 82 based on any criteria, not limited to the above criteria. For example, the control device 100 may switch the start and stop of the operation of the burner heating device 82 based on the detected temperature of the thermistor 98 (the temperature of the heat medium in the circulation flow passage 96).

  The technical elements described in the present specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the techniques exemplified in the present specification or the drawings can simultaneously achieve a plurality of purposes, and achieving one of the purposes itself has technical utility.

2: Hot water supply heating system 10: Tanks 12, 14, 16, 18: Thermistor 20: Tank water circulation path 22: Circulation pump 24: Tap water introduction path 24a: First introduction path 24b: Second introduction path 26: Check valve 28 : Check valve 30: Water amount sensor 32: Tap water supply source 34: Water amount sensor 36: Supply passage 36a: Mixing valve 36b: Bypass passage 36c: Bypass control valve 38: Hot water supply plug 50: Heat pump 52: Refrigerant circulation passage 54: Thermal Exchanger 56: Fan 58: Three-fluid heat exchanger 60: Expansion valve 62: Compressor 70: Systurn 71: Heating medium circulation path 72: Heating outward path 74: Circulation pump 76: Heater 78: Thermistor 81: Burner heating Apparatus 81a: burner 82: burner heating apparatus 82a, 82b, 82c, 82d: burner 84: heating return path 86: thermistor 88: heat recovery path 90: control valve 92: server Star 94: bypass 96: circulation passage 98: Thermistor 100: controller 104: hot water line 106: Heat Pump line 108: Heating system

Claims (2)

A heating system,
A heat pump that heats a heat medium using heat absorbed from the outside air;
A combustor that heats the heat medium using heat generated by burning a fuel;
A heater that heats using the heat of the heat medium;
And a controller.
The burner includes a plurality of burners,
The plurality of burners can respectively burn the fuel.
When the heat transfer medium should be heated using both the heat pump and the combustor, the control device operates only part of the plurality of burners of the combustor to operate the heat medium. Heat the heat medium,
Heating system. When the heat medium should be heated using the burner without using the heat pump, the control device operates all the plurality of burners of the burner to heat the heat medium. To make
A heating system according to claim 1.

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