JP2014009900A - Heat pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a time until an object fluid is heated to reach a target temperature.SOLUTION: Heat pump 1 includes: a refrigerant circuit 10 that is connected to a radiator 13; and a heat medium circuit 100 that is connected to the radiator 13 to circulate a heat medium, and is provided with a heating heat exchanger 102 for heating water in a thermostat bath 103 to be an object fluid with the heat medium heated at 100°C or more by the radiator 13. In the heat pump 1, before a normal operation for heating water in the thermostat bath 13 to a target temperature with the heating heat exchanger 102 is performed, a preheating operation for preheating the water to a preheating temperature with the heating heat exchanger 102 is performed.

Description

    The present invention relates to a heat pump that heats a target fluid to a high temperature, and particularly relates to a measure for improving convenience.

    Conventionally, a heat pump that heats a target fluid by performing a refrigeration cycle is known. For example, the heat pump disclosed in Patent Document 1 includes a refrigerant circuit to which a radiator is connected, and a heat medium that is connected to the radiator to circulate a heat medium and heats a target fluid (in this case, air) by the heat medium. And a heat medium circuit provided with an exchanger. In this heat pump, when a refrigeration cycle is performed, in the radiator, the heat medium is heated by condensation of the refrigerant, and in the heating heat exchanger, the target fluid is heated to a predetermined temperature by the heat medium heated by the radiator. .

JP 2004-132612 A

    In the conventional heat pump, when the heat medium is heated to a high temperature (for example, 100 ° C. or higher) and the target fluid is heated to a high temperature, since the heat load is large, it takes a long time for the target fluid to reach a predetermined temperature. I need it. Therefore, there is a possibility that the time to use the target fluid at a predetermined temperature may be greatly delayed, and there is a problem that convenience is poor.

    The present invention has been made in view of the above points, and an object of the present invention is to improve convenience in a heat pump that heats a target fluid to a high temperature so that the target fluid quickly reaches a predetermined temperature. .

    The first invention includes a refrigerant circuit (10) in which a compression mechanism (11, 12, 16), a radiator (13), an expansion mechanism (14), and an evaporator (15) are connected in order to perform a refrigeration cycle; Heat provided with a heating heat exchanger (102) connected to the radiator (13) to circulate the heat medium and heat the target fluid with the heat medium heated to 100 ° C. or higher by the radiator (13) It is intended for a heat pump with a medium circuit (100). The present invention provides a normal operation in which the target fluid is heated to the target temperature T2 by the heating heat exchanger (102), and the target fluid reaches the preheating temperature T1 at a predetermined start time t1 of the normal operation. The heating heat exchanger (102) includes an execution unit (51) that performs a preheating operation for preheating the target fluid.

    In the first invention, the target fluid is preheated by performing the preheating operation before the user's designated time (predetermined start time t1 of normal operation). When the preheating operation is performed, the target fluid reaches a predetermined preheating temperature T1 at a time designated by the user (a predetermined start time t1 of normal operation). Therefore, if the normal operation is continued after the designated time has elapsed, the target fluid rises by the temperature difference between the target temperature T2 and the preheating temperature T1, and quickly reaches the target temperature T2.

    In a second aspect based on the first aspect, the execution unit (51) can execute a high efficiency mode in which the preheating operation is performed so that the COP of the refrigeration cycle is maximized.

    In the second aspect, when the high efficiency mode is executed as the preheating operation, the COP (coefficient of performance) of the refrigeration cycle is the highest. Therefore, although the heating speed of the target fluid is relatively slow, the target fluid is heated to the preheating temperature T1 with low power consumption.

    In the third aspect of the invention, in the second aspect of the invention, the execution unit (51) performs the preheating operation so that the heating capacity of the radiator (13) is higher than that in the high efficiency mode. And any one of the high-efficiency modes.

    In the said 3rd invention, when high heating mode is performed as preheating operation, the heating capability of a radiator (13) will become higher than the time of performing high efficiency heat mode. Therefore, although the power consumption is higher than that in the high efficiency heat mode, the target fluid is heated to the preheating temperature T1 in a short time.

    In the fourth invention, in the second or third invention, the execution unit (51) calculates and updates an index value indicating a temperature change of the target fluid during the preheating operation for each preheating operation. (53b) and a calculation unit (53c) for obtaining an operation time Δt scheduled for the next preheating operation from the index value updated by the updating unit (53b) and the temperature increase ΔT scheduled for the next preheating operation And have.

    In the fourth aspect of the invention, even if the tendency of the temperature change of the target fluid (the relationship between the heating time and the temperature of the target fluid) changes every day, it is based on the index value that is always updated during the preheating operation. Since the operation time Δt of the next preheating operation is obtained, the temperature error of the preheating operation becomes small.

    In the fifth aspect based on the first aspect, the execution unit (51) is configured such that the operation time Δt of the preheating operation is designated by a user and the operation time Δt has elapsed since the start of the preheating operation. Time specification for switching the high-efficiency operation where the COP is maximum and the high-heat operation where the heating capacity of the radiator (13) is higher than the high-efficiency operation so that the target fluid reaches the preheating temperature T1 The mode is executable.

    In the fifth aspect, when the time designation mode is executed as the preheating operation, the high efficiency operation and the high heating operation are switched and executed with an appropriate time distribution. When the time Δt specified by the user has elapsed, the target fluid reaches the preheating temperature T1.

    In the sixth aspect of the invention, in the fifth aspect of the invention, the execution unit (51) includes an index value indicating a temperature change of the target fluid during the high efficiency operation and a target fluid during the high heating operation for each preheating operation. An update unit (53b) that calculates and updates an index value indicating a temperature change of the above, the two index values updated by the update unit (53b), and the operation time Δt that is scheduled for the next preheating operation, And a calculation unit (53c) for obtaining the operation time Δta of the high-efficiency operation and the operation time Δtb of the high heating operation scheduled in the next preheating operation from the temperature increase ΔT scheduled in the next preheating operation. doing.

    In the sixth aspect of the invention, even if the tendency of the temperature change of the target fluid (the relationship between the heating time and the temperature of the target fluid) changes every day, the two index values always updated during the preheating operation are used. Based on this, since the operation times Δta and Δtb of the two operations of the next preheating operation are obtained, the temperature error of the preheating operation becomes small.

    In the seventh aspect of the invention, in the third aspect of the invention, the auxiliary heating unit (107) for heating the heating medium is connected to the heating medium circuit (100), and the execution unit (51) is connected to the high heating unit. The auxiliary heating unit (107) is heated when performing the preheating operation in the mode.

    In the seventh aspect, since the heating of the heat medium is started by the auxiliary heating unit (107) when the preheating operation in the high heating mode is started, the target fluid is more than in the case where there is no auxiliary heating unit (107). The ability to heat is increased.

    The eighth invention includes the auxiliary heating unit (108) for heating the target fluid in the third invention, and the execution unit (51) performs the auxiliary heating when performing the preheating operation in the high heating mode. The heating unit (108) is heated.

    In the eighth invention, since the heating of the target fluid is started by the auxiliary heating unit (108) when the preheating operation in the high heating mode is started, the target fluid is more than in the case where there is no auxiliary heating unit (108). The ability to heat is increased.

    According to the present invention, the target fluid is preheated by performing the preheating operation before the user's designated time (the predetermined start time t1 of the normal operation). By doing so, the target fluid can be quickly brought to the target temperature T2 after the user-specified time has elapsed. As a result, it is possible to avoid a situation in which the timing of using the target fluid at the predetermined temperature is greatly delayed, and the convenience of the heat pump (1) can be improved.

    According to the second invention, the high efficiency mode can be executed as the preheating operation. By doing so, the power consumption during the preheating operation can be suppressed as low as possible.

    According to the third invention, the high heating mode can be further executed as the preheating operation. By so doing, preheating can be completed in a short time reliably when there is not enough time.

    According to the fourth invention, when either the high efficiency mode or the high heating mode is executed, the index value indicating the temperature change of the target fluid during the preheating operation is calculated and updated every time the preheating operation is performed. Based on the above index value, the operation time Δt of the next preheating operation is obtained. By doing so, even when the tendency of the temperature change of the target fluid (the relationship between the heating time and the temperature of the target fluid) changes every day, the temperature error can be reduced and the preheating operation can be performed with high accuracy.

    According to the fifth aspect, the time designation mode can be executed as the preheating operation. By so doing, preheating can be reliably completed at a user-specified time while keeping power consumption low.

    According to the sixth invention, when the time designation mode is executed, the index value indicating the temperature change of the target fluid during the high-efficiency operation and the index indicating the temperature change of the target fluid during the high-heating operation for each preheating operation. The values were calculated and updated, and the operation times Δta and Δtb of the two operations of the next preheating operation were obtained based on the two updated index values. By doing so, even when the tendency of the temperature change of the target fluid (the relationship between the heating time and the temperature of the target fluid) changes every day, the temperature error can be reduced and the preheating operation can be performed with high accuracy.

    According to the seventh aspect, during the preheating operation in the high heating mode, the auxiliary heating unit (107) that heats the heat medium is heated. Thereby, the capability of heating the target fluid can be increased, and the preheating of the target fluid can be completed in a shorter time.

    According to the eighth aspect of the invention, during the preheating operation in the high heating mode, the auxiliary heating unit (108) for heating the target fluid is heated. Thereby, the capability of heating the target fluid can be increased, and the preheating of the target fluid can be completed in a shorter time.

FIG. 1 is a piping diagram illustrating a configuration of a heat pump according to the first embodiment. FIG. 2 is a control flowchart of the timer starting unit according to the first embodiment. FIG. 3 is a diagram illustrating a temperature change of the target fluid (water in the thermostatic bath) during the preheating operation in the energy saving mode. FIG. 4 is a diagram illustrating a temperature change of the target fluid (water in the thermostatic bath) during the preheating operation in the rapid heating mode. FIG. 5 is a diagram illustrating a temperature change of the target fluid (water in the thermostatic bath) during the preheating operation in the time designation mode. FIG. 6 is a piping diagram illustrating a configuration of a heat pump according to a modification of the first embodiment. FIG. 7 is a piping diagram illustrating the configuration of the heat pump according to the second embodiment. FIG. 8 is a piping diagram illustrating the configuration of the heat pump according to the third embodiment.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

Embodiment 1
The heat pump (1) of this embodiment is used for industrial purposes, and heats the target fluid to a high temperature. As shown in FIG. 1, the heat pump (1) includes a refrigerant circuit (10), a heat medium circuit (100), and a controller (50).

    The refrigerant circuit (10) performs a two-stage compression refrigeration cycle by circulating the refrigerant. The refrigerant circuit (10) includes a low-stage compressor (11) and a high-stage compressor (12), a radiator (13), an expansion valve (expansion mechanism) (14), and an evaporator (15). Are sequentially connected by refrigerant piping. In the present embodiment, R245fa is used as the refrigerant.

    Although not shown, the low-stage compressor (11) and the high-stage compressor (12) are configured in a completely sealed manner, and the inside of the casing that houses the compression section and the motor that rotationally drives the compression section is the suction pressure. It has a so-called low-pressure dome shape. That is, in each compressor (11, 12), the suction refrigerant flows into the casing, and the refrigerant compressed by the compression unit is directly discharged out of the casing without flowing into the casing. Each of the compressors (11, 12) is configured to have a variable operating rotational speed. Both compressors (11, 12) are connected in series to compress the refrigerant in two stages, and constitute a refrigerant compression mechanism.

    The radiator (13) has a low temperature channel (13a) and a high temperature channel (13b). The high temperature flow path (13b) has an inflow end connected to the discharge side of the high stage compressor (12) and an outflow end connected to a supercooling heat exchanger (21) described later. On the other hand, the low-temperature flow path (13a) of the radiator (13) is connected to the heat medium circuit (100). In the radiator (13), the high-pressure refrigerant flowing through the high-temperature channel (13b) and the heat medium (for example, water or oil) of the heat medium circuit (100) flowing through the low-temperature channel (13a) exchange heat, Is heated to 100 ° C. or higher (for example, 120 ° C.).

    The expansion valve (14) is an electronic expansion valve whose opening degree can be adjusted.

    The evaporator (15) has a low temperature channel (15a) and a high temperature channel (15b). The low temperature flow path (15a) has an inflow end connected to the expansion valve (14) and an outflow end connected to the suction side of the low-stage compressor (11). On the other hand, the high temperature flow path (15b) of the evaporator (15) is connected to the cold water circuit (110). In the evaporator (15), the low-pressure refrigerant flowing through the low-temperature channel (15a) and the water in the cold water circuit (110) flowing through the high-temperature channel (15b) exchange heat to cool the water.

    The refrigerant circuit (10) is provided with a supercooling heat exchanger (21) and an injection passage (22). The supercooling heat exchanger (21) is connected between the radiator (13) and the expansion valve (14), and has a high temperature channel (21a) and a low temperature channel (21b). The injection passage (22) has an inflow end connected between the radiator (13) and the supercooling heat exchanger (21), and an outflow end at the low-stage compressor (11) and the high-stage compressor (12 ) Is connected between. A flow rate adjusting valve (23) is provided in the injection passage (22). The flow rate adjustment valve (23) also has an action of depressurizing the refrigerant that passes therethrough.

    The high-temperature channel (21a) of the supercooling heat exchanger (21) has an inflow end connected to the radiator (13) and an outflow end connected to the expansion valve (14). The low temperature flow path (21b) of the supercooling heat exchanger (21) is connected to the downstream side of the flow rate adjustment valve (23) in the injection path (22). In the supercooling heat exchanger (21), heat is exchanged between the outlet refrigerant of the radiator (13) flowing through the high-temperature channel (21a) and the branch refrigerant of the outlet refrigerant flowing through the low-temperature channel (21b). While the outlet refrigerant of (21a) is supercooled, the branch refrigerant of the low temperature channel (21b) evaporates. The injection passage (22) converts the branched refrigerant evaporated in the supercooling heat exchanger (21) into an intermediate pressure refrigerant between the low-stage compressor (11) and the high-stage compressor (12), that is, a compression mechanism. The refrigerant is joined with the refrigerant in the middle of compression.

    The heat medium circuit (100) circulates the heat medium and heats water as the target fluid by the heat medium heated by the radiator (13). A pump (101) and a heating heat exchanger (102) are connected to the heat medium circuit (100).

    The pump (101) circulates the heat medium.

    The heating heat exchanger (102) is provided in a thermostat (103) that stores water (target fluid). In the heating heat exchanger (102), the heat medium flowing through the heat medium circuit (100) and the water in the thermostat (103) exchange heat, and the water is heated to a constant temperature (for example, 80 ° C.). Further, a water temperature sensor (105) for detecting the temperature of water is provided in the constant temperature bath (103).

    The controller (50) controls the operation of the heat pump (1). The controller (50) includes a timer starting unit (51).

    In the timer starting part (51), the timer starting operation for completing the starting at the time designated by the user is controlled. The timer start operation is classified into an operation until the start is completed and an operation after the start is completed. In the operation until the start-up is completed, the water in the thermostatic chamber (103) is heated in advance. On the other hand, in the operation after the start is completed, the water in the thermostatic bath (103) is heated to the target temperature T2 (for example, 80 ° C.). That is, the timer starter (51) performs a preheating operation for preheating water in the thermostat (103) and a normal operation for heating water in the thermostat (103) to the target temperature T2 after the preheating operation. And constitutes the execution unit of the present invention. The timer starting part (51) has a normal operation control part (52) and a preheating operation control part (53).

    The normal operation control unit (52) controls normal operation. In the normal operation control unit (52), the normal operation start time (start-up completion time) t1 and the target temperature T2 are set by the user.

    The preheating operation control unit (53) controls the preheating operation. The preheating operation control unit (53) includes a setting unit (53a), an update unit (53b), and a calculation unit (53c).

    In the setting unit (53a), the target temperature for preheating (preheating temperature T1) and the operation mode for preheating operation are set by the user. The setting unit (53a) selects one of the three operation modes of the energy saving mode (high efficiency mode), the rapid heating mode (high heating mode), and the time designation mode.

    The update unit (53b) calculates and updates an index value (temperature coefficient α in this embodiment) indicating the temperature change of the water in the thermostat (103) during the preheating operation every time the preheating operation is performed. It is.

    The calculation unit (53c) uses the index value (temperature coefficient α) updated by the updating unit (53b) to operate the energy saving mode operation time Δt, the rapid heating mode operation time Δt, and the time designation mode energy saving operation (high The operation time Δta of the efficiency operation) and the operation time Δtb of the rapid heating operation (high heating operation) are calculated.

<Operation of heat pump>
When the operation of the heat pump (1) is started, both compressors (11, 12) are driven, and the refrigerant compressed by the low-stage compressor (11) is further compressed by the high-stage compressor (12) Becomes a refrigerant. The high-pressure refrigerant discharged from the high-stage compressor (12) is condensed by exchanging heat with the heat medium of the heat medium circuit (100) in the radiator (13), and the heat medium is 100 ° C. or higher (for example, 120 ° C. ). A part of the high-pressure refrigerant condensed in the radiator (13) flows into the injection passage (22), and the rest flows into the high-temperature channel (21a) of the supercooling heat exchanger (21). The high-pressure refrigerant that has flowed into the injection passage (22) is depressurized by the flow rate adjustment valve (23), and then flows into the low-temperature flow path (21b) of the supercooling heat exchanger (21) to the high-pressure flow path (21a). Exchange heat with refrigerant. As a result, the high-pressure refrigerant in the high-temperature channel (21a) is supercooled, while the refrigerant in the low-temperature channel (21b) evaporates to become an intermediate-pressure superheated gas refrigerant. The high-pressure refrigerant in the high-temperature flow path (21a) is reduced in enthalpy of the refrigerant by being supercooled.

    The high-pressure refrigerant supercooled by the supercooling heat exchanger (21) is decompressed by the expansion valve (14) to become a low-pressure refrigerant. The low-pressure refrigerant flows into the evaporator (15), exchanges heat with the heat source water of the cold water circuit (110) and evaporates, and the heat source water is cooled to become cold water. Since the enthalpy of the low-pressure refrigerant flowing through the evaporator (15) is reduced by the amount of supercooling as described above, the evaporation capacity (cooling capacity) of the evaporator (15) increases. The refrigerant flowing out of the evaporator (15) is sucked into the low stage compressor (11) and compressed again. The refrigerant discharged from the low-stage compressor (11) joins the intermediate-pressure superheated gas refrigerant from the injection passage (22) and is sucked into the high-stage compressor (12).

    In the heat medium circuit (100), the heat medium heated by the radiator (13) flows to the heating heat exchanger (102) and exchanges heat with water in the thermostat (103), and in the thermostat (103). Water is heated to the target temperature T2.

    However, in the heat pump (1), if the heating medium is heated to 100 ° C. or higher and the water in the thermostatic chamber (103) is heated to a high temperature, the heat load is large. It takes a lot of time to reach the target temperature T2. For this reason, there is a possibility that the time to use the hot water of the target temperature T2 may be greatly delayed, and there is a problem that convenience is poor.

    Therefore, in the heat pump (1) of the present embodiment, a timer start operation is performed so that the water in the thermostatic bath (103) quickly reaches the target temperature T2.

<Timer start operation>
In the timer starting part (51) of the controller (50), the timer starting operation is performed in the control flow shown in FIG.

    First, in step ST1, the user setting is performed before the timer start operation (before the preheating operation is started). Specifically, the operation mode of the preheating operation, the target temperature (preheating temperature T1) of the water in the constant temperature bath (103) in the preheating operation, the start time t1 (start-up completion time) of the normal operation, and the constant temperature in the normal operation A target temperature T2 of water in the tank (103) is set. As the operation mode of the preheating operation, one of the energy saving mode, the rapid heating mode, and the time designation mode is selected. Further, when the time designation mode is selected, the operation time Δt of the preheating operation is set.

    Next, in step ST2, when the energy saving mode or the rapid heating mode is selected in step ST1, the calculation unit (53c) calculates the operation time Δt of the preheating operation.

    Specifically, the operation time Δt of the preheating operation includes the temperature T0 (measured value) of the water in the thermostat (103) before the start of the timer start operation (before the start of the preheating operation) and the preheating temperature T1 set in step ST1. And the temperature coefficient α (the heating time required to raise the water in the thermostatic chamber (103) by 1 ° C.) (1). (Here, T1-T0 corresponds to the temperature increase ΔT scheduled in the preheating operation.)

    At this time, in the first preheating operation, the initial value α0 of the temperature coefficient obtained by the calculation unit (53c) during the trial operation is used, and the second and subsequent preheating operations are performed during the previous preheating operation. The update value αnew of the temperature coefficient obtained by the calculation unit (53c) is used. Then, when the operation time Δt of the preheating operation is obtained, the process proceeds to step ST4.

    In Step ST3, when the time designation mode is selected in Step ST1, the calculation unit (53c) calculates the energy saving operation time Δta and the rapid heating operation time Δtb.

    Specifically, the operation times Δta and Δtb of each operation are the temperature T0 (measured value) of the water in the thermostatic chamber (103) before the start of the timer start operation (before the start of the preheat operation) and the preheat set in step ST1. It is calculated from the relational expressions (2) and (3) of the temperature T1, the operating time Δt set in step ST1, the temperature coefficient αa during the energy saving operation, and the temperature coefficient αb during the rapid heating operation. (Here, T1-T0 corresponds to the temperature increase ΔT scheduled in the preheating operation.)

    At this time, the initial temperature coefficients αa0 and αb0 obtained by the calculation unit (53c) during the trial operation are used during the first preheating operation, and the temperature coefficients αa and αb during each operation are used for the second and subsequent preheating operations. The temperature coefficient update values αanew and αbnew obtained by the calculation unit (53c) during the previous preheating operation are used. When the operation times Δta and Δtb of each operation are obtained, the process proceeds to step ST4.

    In step ST4, timer start operation (preheating operation) is started. The preheating operation is started at a time (preheating operation start time t0) that is back by the operation time Δt of the preheating operation from the user-set normal operation start time t1 (preheating operation end time).

    In the energy saving mode, when the preheating operation is started, the refrigeration cycle is controlled so that the COP of the refrigeration cycle is maximized. As shown in FIG. 3, the heating rate of the water in the thermostat (103) is relatively high. Slow and low power consumption.

    In the case of the rapid heating mode, when the preheating operation is started, the refrigeration cycle is controlled so that the heating capacity of the radiator (13) is higher than that in the energy saving mode, and as shown in FIG. The water is heated at a relatively high rate and power consumption is high.

    In the time designation mode, when the preheating operation is started, as shown in FIG. 5, first, the energy saving operation that maximizes the COP of the refrigeration cycle is performed by Δta, and then the radiator (13) rather than the energy saving operation. A rapid heating operation having a high heating capacity is performed by Δtb.

    Next, in step ST5, the preheating operation control unit (53) determines whether or not to end the preheating operation. The end of the preheating operation is determined based on the temperature of the water in the thermostat (103). Specifically, when the temperature of the water in the thermostat (103) is lower than the preheating temperature T1, it is determined that the preheating operation is being performed, and the preheating operation is continued. Then, when the temperature of the water in the thermostat (103) reaches the preheating temperature T1, it is determined that the preheating operation is finished. At this time, the actual operation time Δt ′ of the preheating operation (the time from the start time t0 of the preheating operation to the temperature of the water in the constant temperature bath (103) reaches the preheating temperature T1) is stored in the calculation unit (53c). Then, it progresses to step ST6.

    Next, in step ST6, the start-up is completed, and the operation is shifted from the preheating operation to the normal operation. In normal operation, the refrigeration cycle is controlled so as to maintain the target temperature T2 after the temperature of the water in the thermostat (103) reaches the target temperature T2.

    Next, in step ST7, the update unit (53b) updates the temperature coefficient α.

    In the case of the energy saving mode or the rapid heating mode, the updated value αnew of the temperature coefficient is determined by the actual operation time Δt ′ of the preheating operation stored in step ST5 and the temperature T0 of the water in the constant temperature bath (103) before the start of the preheating operation. Measured value) and the average value of α ′ calculated from the relational expression (4) between the preheating temperature T1 set in step ST1 and the temperature coefficient αold before the update. (See relational expression (5)) This updated value αnew is used when calculating the operation time Δt of the preheating operation in step ST2 during the next preheating operation.

    In the time designation mode, the updated values αanew and αbnew of the temperature coefficient at each operation are the operation time Δta (calculated value) of the energy saving operation, the actual operation time Δt ′ of the preheating operation stored in step ST5, and the preheating operation The temperature T0 (measured value) of the water in the thermostat (103) before the start, the temperature Tab (measured value) of the water in the thermostat (103) when switching from the energy saving operation to the rapid heating operation, and step ST1 First, αa ′ and αb ′ are calculated from the relational expressions (6) and (7) with the preheating temperature T1 set in (1). The updated values αanew and αbnew are obtained as average values of the calculated αa ′ and αb ′ and the temperature coefficients αaold and αbold before the update. (Refer to relational expression (8)) The updated values αanew and αbnew are used when calculating the operation time Δta and Δtb of each operation in step ST3 during the next preheating operation.

-Effect of the embodiment-
According to this embodiment, the timer start operation can be executed. Specifically, the operation is started (preheating operation) before the user's designated time (predetermined start time t1 of normal operation), and the water in the thermostat (103) is preheated to the preheating temperature T1. . By doing so, the water in the thermostatic chamber (103) can be quickly brought to the target temperature T2 after the time specified by the user has elapsed. As a result, it is possible to avoid a situation in which the time for using the hot water at the target temperature T2 is greatly delayed, and the convenience of the heat pump (1) can be improved.

    Further, according to the present embodiment, one of the three operation modes of the preheating operation (energy saving mode, rapid heating mode, and time designation mode) is selected and executed. By doing so, the user can change the content of the preheating operation according to the request. When the energy saving mode is executed, the power consumption can be minimized. In addition, when the rapid heating mode is executed, preheating can be reliably completed in a short time even when there is not enough time. In addition, when the time designation mode is executed, preheating can be reliably completed at a user designated time while keeping power consumption low.

    Further, according to the present embodiment, when executing either the energy saving mode or the rapid heating mode, the temperature coefficient α is calculated and updated every time the preheating operation is performed, and based on the updated temperature coefficient αnew. The operation time Δt of the next preheating operation is obtained. As a result, even if the tendency of the temperature change of the water in the thermostatic chamber (103) (the relationship between the heating time and the temperature of the water) changes every day, the temperature error is reduced and the preheating operation is performed with high accuracy. Can do.

    Further, according to the present embodiment, when the time designation mode is executed, the temperature coefficients αa and αb are calculated and updated every time the preheating operation is performed, and based on the updated temperature coefficients αanew and αbnew, The operation times Δta and Δtb of the next preheating operation are obtained. As a result, even if the tendency of the temperature change of the water in the thermostatic chamber (103) (the relationship between the heating time and the temperature of the water) changes every day, the temperature error is reduced and the preheating operation is performed with high accuracy. Can do.

<Modification of Embodiment 1>
In the first embodiment, the refrigerant circuit (10) is provided with the supercooling heat exchanger (21), the flow rate adjusting valve (23), and the injection passage (22). However, the configuration of the refrigerant circuit (10) is not limited thereto. For example, as shown in FIG. 6, the refrigerant circuit (10) includes a compressor (16), a radiator (13), an expansion valve (14), and The configuration may be such that the evaporators (15) are simply connected in order.

<< Embodiment 2 >>
The heat pump (1) of the second embodiment is obtained by adding a means for heating a heat medium to the heat pump (1) of the modification of the first embodiment. That is, in the heat medium circuit (100) of the modified example of the first embodiment, only the radiator (13) is provided to heat the heat medium, but the heat medium circuit (100) of the second embodiment is provided. As shown in FIG. 7, a heater (107) (auxiliary heating unit) is provided in addition to the radiator (13).

    The heater (107) is controlled to be turned on / off by the preheating operation control unit (53) of the timer starting unit (51), and is configured to be turned on during the preheating operation in the rapid heating mode to perform the heating operation. .

    In the second embodiment, when the preheating operation in the rapid heating mode is started, heating of the heat medium by the heater (107) is started. Therefore, the ability to heat the water in the thermostat (103) can be increased, and the preheating of the water can be completed in a shorter time.

    The heater (107) may be any one that heats the heat medium, and any heat source may be used, such as an electric heater, an IH heater, a steam heat source, or a gas cooker.

<< Embodiment 3 >>
The heat pump (1) of the third embodiment is obtained by adding means for heating water in the thermostatic chamber (103) to the heat pump (1) of the first embodiment. That is, only the heating heat exchanger (102) is provided in the thermostat (103) of the first embodiment to heat water, but the thermostat (103) of the third embodiment has FIG. As shown in FIG. 4, a heater (108) (auxiliary heating unit) is provided in addition to the heat exchanger (102).

    The heater (108) is composed of, for example, a sheathed heater. The heater (108) is controlled to be turned on / off by the preheating operation control unit (53) of the timer starting unit (51) and is turned on during the preheating operation in the rapid heating mode to perform the heating operation. Yes.

    In the third embodiment, when the preheating operation in the rapid heating mode is started, heating of the water in the thermostatic chamber (103) by the heater (108) is started. Therefore, the ability to heat the water in the thermostat (103) can be increased, and the preheating of the water can be completed in a shorter time.

    The heater (108) may be any one that heats the water in the thermostatic chamber (103), and any heat source may be used such as an electric heater, an IH heater, a steam heat source, and a gas cooker.

<< Other Embodiments >>
In the above embodiment, the temperature coefficient α is used as an index value indicating the temperature change of the water in the constant temperature bath (103) during the preheating operation. However, the index value is not limited to the temperature coefficient α, and may be, for example, a temperature gradient (a rise in water temperature per unit time).

    In the above embodiment, the target fluid is not limited to water, and other fluids such as air and oil may be used.

    In the above embodiment, the refrigerant is not limited to R245fa, and other refrigerants having a critical temperature exceeding 100 ° C. may be used.

    Moreover, in the said embodiment, you may use what is called a high-pressure dome type for each compressor (11,12,16).

    The present invention is useful for a heat pump that heats a target fluid to a high temperature.

1 Heat pump 10 Refrigerant circuit 11 Low stage compressor (compression mechanism)
12 High stage compressor (compression mechanism)
13 Radiator 14 Expansion Valve (Expansion Mechanism)
15 Evaporator 16 Compressor (Compression mechanism)
51 Timer start part (execution part)
53b Update unit 53c Calculation unit 100 Heat medium circuit 102 Heating heat exchanger 107 Heater (auxiliary heating unit)
108 Heater (auxiliary heating part)

Claims (8)

A refrigerant circuit (10) that performs a refrigeration cycle by sequentially connecting a compression mechanism (11, 12, 16), a radiator (13), an expansion mechanism (14), and an evaporator (15);
Heat provided with a heating heat exchanger (102) connected to the radiator (13) to circulate the heat medium and heat the target fluid with the heat medium heated to 100 ° C. or higher by the radiator (13) A heat pump comprising a medium circuit (100),
A normal operation in which the target fluid is heated to the target temperature T2 by the heating heat exchanger (102), and the heating heat exchanger (102) so that the target fluid reaches the preheating temperature T1 at a predetermined start time t1 of the normal operation. 102) A heat pump comprising an execution unit (51) for executing a preheating operation for preheating the target fluid in step 102). In claim 1,
The said execution part (51) can perform the high efficiency mode which performs the said preheating operation so that COP of a refrigerating cycle may become the maximum, The heat pump characterized by the above-mentioned. In claim 2,
The execution unit (51) is configured to execute either the high heating mode in which the preheating operation is performed or the high efficiency mode so that the heating capacity of the radiator (13) is higher than that in the high efficiency mode. Features heat pump. In claim 2 or 3,
The execution unit (51) calculates and updates an index value indicating a temperature change of the target fluid during the preheating operation for each preheating operation, and the index updated by the updating unit (53b) A heat pump characterized by having a calculation unit (53c) for obtaining an operation time Δt scheduled for the next preheating operation from the value and the temperature rise ΔT scheduled for the next preheating operation. In claim 1,
The execution unit (51) performs COP so that the operation time Δt of the preheating operation is designated by the user and the target fluid reaches the preheating temperature T1 at the time when the operation time Δt has elapsed from the start of the preheating operation. A heat pump characterized by being capable of executing a time designation mode for switching between a high-efficiency operation in which the heat is maximized and a high-heating operation in which the heating capacity of the radiator (13) is higher than that of the high-efficiency operation. In claim 5,
The execution unit (51) calculates and updates an index value indicating a temperature change of the target fluid during the high efficiency operation and an index value indicating a temperature change of the target fluid during the high heating operation for each preheating operation. From the update unit (53b), the two index values updated by the update unit (53b), the operation time Δt scheduled for the next preheating operation, and the temperature increase ΔT scheduled for the next preheating operation A heat pump comprising: a calculation unit (53c) for obtaining an operation time Δta of the high-efficiency operation scheduled in the next preheating operation and an operation time Δtb of the high-heating operation. In claim 3,
An auxiliary heating unit (107) for heating the heat medium is connected to the heat medium circuit (100),
The execution unit (51) heats the auxiliary heating unit (107) when performing the preheating operation in the high heating mode. In claim 3,
An auxiliary heating unit (108) for heating the target fluid;
The execution unit (51) heats the auxiliary heating unit (108) when performing the preheating operation in the high heating mode.

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