JP2011185488A - Hot water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply device capable of properly controlling a flow rate of hot water/water circulated in a heat pump heat source machine in starting a heating operation of the heat pump heating machine by control of small processing burden. <P>SOLUTION: This hot water supply device includes a hot water storage tank (3), a heating means (7) for heating hot water/water in the hot water storage tank, a pump (P1) for circulating the hot water/water in the hot water storage tank to the heating means, a control means (10g) for controlling a draining amount of the pump so that the hot water/water flowing into the heating means reaches a target temperature, and a determining means (10f) for determining the draining amount of the pump on the basis of a value obtained by dividing a rated capacity of the heating means by temperature difference between a water temperature of the water flowing into the heating means, that is, the water temperature for allowing the heating means to exert the rated capacity and the target temperature, and the control means controls the draining amount of the pump in starting the heating operation of the heating means, to reach the draining amount determined by the determining means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus that heats hot water in a hot water storage tank by a heat pump heat source device.

  The hot water supply device includes, for example, a heat pump heat source machine and a hot water storage tank. A heat pump heat source machine includes, for example, a compressor that compresses a heating medium, a heat exchanger that heats hot water by performing heat exchange between the medium compressed by the compressor and hot water from a hot water storage tank, and a heat An expansion valve that depressurizes the medium flowing out from the exchanger, and an evaporator that evaporates the medium depressurized by the expansion valve. A pipe for circulating hot water in the hot water storage tank to the heat exchanger is arranged between the heat pump heat source machine and the hot water storage tank, and the pipe is used to send hot water in the hot water storage tank to the heat exchanger. A pump is provided. As such a hot water supply device, for example, the one shown in Patent Document 1 is known.

JP 2003-222396 A

  The heat pump heat source machine is heated so that hot water from the hot water storage tank is heated in the heat exchanger to become hot water at a target temperature. However, if the flow rate of hot water circulating through the heat exchanger at the start of the heating operation is not appropriate, the refrigerant path (heat exchanger, expansion valve, and heat pump) in the transient state from the start of the heating operation to the stable state A phenomenon occurs in which the pressure in the piping connecting the compressors rises excessively, and the temperature of the hot water discharged from the heat exchanger does not reach the target temperature by hunting (ie, oscillating unstably). When the former phenomenon occurs, it causes the problem that the heating operation of the heat pump heat source machine is stopped, and when the latter phenomenon occurs, the hot water heated by the heat exchanger does not reach the target temperature and cannot be used effectively. Invite.

  In order to solve these problems, the flow rate of the hot water circulating through the heat exchanger at the start of the heating operation of the heat pump heat source unit is set to an appropriate flow rate (that is, the temperature of the hot water heated by the heat pump heat source unit is not hunting and the heat pump It is necessary to control the flow rate so that the pressure of the refrigerant path in the heat source machine does not increase excessively. In that case, it is desirable to devise so as to reduce the processing load of the control.

  An object of the present invention is to solve the above-described problems, and appropriately controls the flow rate of hot water circulating to the heat pump heat source device at the start of the heating operation of the heat pump heat source device by control with a small processing load. An object of the present invention is to provide a hot water supply device that can be controlled to a proper flow rate.

In order to solve the above problems, a first aspect of the present invention includes a hot water storage tank (3), heating means (7) for heating hot water in the hot water storage tank by heat exchange by a refrigeration cycle, and the hot water storage tank. A pump (P1) for circulating hot water in the heating means and returning it into the hot water storage tank, and a control means (10g) for controlling the amount of drainage of the pump so that the hot water flowing into the heating means reaches a target temperature and flows out. ) And the value obtained by dividing the rated capacity of the heating means by the temperature difference between the target temperature and the water temperature of the water flowing into the heating means and the heating means exhibiting the rated capacity Determining means (10f) for determining the amount of drainage of the pump, and the control means (10g) determines the amount of drainage of the pump at the start of the heating operation of the heating means by the determining means (10f). And controls so as to be constant has been drained weight.

  According to a second aspect of the present invention, there is provided the hot water supply apparatus according to the first aspect, further comprising water temperature detection means (10c, 10cB) for detecting the temperature of the supplied water supplied to the hot water storage tank. The means (10f) uses the water temperature of the supplied water detected by the water temperature detecting means as the water temperature at which the water flowing into the heating means and the heating means exhibits the rated capacity. is there.

  A third aspect of the present invention is the hot water supply apparatus according to the second aspect, wherein the water temperature detecting means (10c) includes an outside air temperature detecting means (10i) for detecting an outside air temperature, the outside air temperature, and the Processing means (10j) for obtaining the water temperature of the supplied water from the outside air temperature detected by the outside air temperature detecting means based on the correspondence relationship with the water temperature of the supplied water.

  A fourth aspect of the present invention is the hot water supply apparatus according to the third aspect, wherein the heating means (7) is provided with one or more temperature sensors (7a), and the outside air temperature detecting means ( 10i) obtains the outside air temperature from one or a plurality of detected values of the one or more temperature sensors when the heating means has not performed the heating operation for a predetermined time.

  A fifth aspect of the present invention is the hot water supply apparatus according to the second aspect, wherein the water temperature detection means (10cB) includes a temperature sensor (T5) disposed at a lower portion of the hot water storage tank (3). And a processing means (10jB) for determining the lowest temperature among the temperatures detected by the temperature sensor within a predetermined time as the water temperature of the supplied water.

  A sixth aspect of the present invention is the hot water supply apparatus according to any one of the first to fifth aspects, wherein the control means (10g) is a flow rate instruction value based on the amount of drainage determined by the determination means. And the amount of drainage of the pump at the start of the heating operation of the heating means (7) is controlled based on the flow rate instruction value, and the flow rate instruction value is a linear function of the drainage amount.

  A seventh aspect of the present invention is the hot water supply apparatus according to any one of the first to sixth aspects, wherein the heating means (7) includes a compressor (7b) for compressing a heating medium, and the compression. A heat exchanger (7c) for performing heat exchange between the heating medium compressed by a heater and hot water from the hot water storage tank (3) to heat the hot water with the heating medium, and the heat exchange An expansion valve (7d) for depressurizing the heating medium flowing out from the vessel, and an evaporator (7e) for evaporating the heating medium depressurized by the expansion valve.

  According to the first aspect of the present invention, the flow rate of the hot water circulating through the heating unit at the start of the heating operation of the heating unit is set to an appropriate flow rate (that is, the temperature of the hot water heated by the heating unit is not hunted and the heating unit is It is possible to control the flow rate so that the pressure of the refrigerant path inside does not increase excessively. Moreover, since the rated capacity (that is, a fixed value) of the heating means is used for calculation of an appropriate flow rate, the calculation processing load (that is, control load) can be reduced.

  According to the second aspect of the present invention, when heating water having the same water temperature as the supply water, the heating means exhibits the rated capacity, but the water temperature of the supply water changes according to environmental conditions (for example, outside air temperature). To do. Even if environmental conditions (for example, outside air temperature) change by using the water temperature detection means that detects the water temperature of the feed water, it is possible to always detect the water temperature at which the heating means at that time exhibits its rated capacity. It is possible to determine an appropriate amount of drainage of the pump at the start of operation of the heating means regardless of a change in (for example, the outside air temperature).

  According to the third aspect of the present invention, the water temperature of the feed water can be regarded as the same as the temperature of the tap water, but this is correlated with the outside air temperature. Therefore, it is possible to easily detect the temperature of the supplied water based on the outside air temperature detected by the outside air temperature detecting means.

  According to the fourth aspect of the present invention, the heating means is provided with a plurality of temperature sensors in the inside or the outer periphery thereof for controlling the heating means. If the heating means has stopped operating and the stopped state has continued for a certain period of time, the elements constituting the heating means (heat exchanger, compressor, temperature sensor described above, etc.) Equilibrium with temperature (generally outside temperature). Therefore, since the detected value of the temperature sensor detected at that time can be regarded as the outside air temperature, the detected value can be used for the control of the third mode.

  According to the fifth aspect of the present invention, the supply water accumulates in the lower part of the hot water storage tank, so that it can be supplied at low cost by using the temperature sensor (ie, the existing temperature sensor) disposed in the lower part of the hot water storage tank. The water temperature can be detected.

  According to the sixth aspect of the present invention, the flow rate instruction amount can be determined so that the fluctuation of the drainage amount is linearly reflected.

  According to the seventh aspect of the present invention, a refrigeration cycle heat exchange type heating means can be configured using a known technique.

It is a block schematic diagram of the hot water supply apparatus of 1st and 2nd embodiment. It is a block schematic diagram of the control device of the first embodiment. It is a block schematic diagram of the control device of the second embodiment. It is a figure explaining the relationship between each temperature and enthalpy of hot water and a heating medium. It is a figure explaining that (DELTA) h / (DELTA) t is substantially constant with respect to the raise of tw, in. It is another figure explaining that (DELTA) h / (DELTA) t is substantially constant with respect to the raise of tw, in. It is the figure which showed an example of the correspondence of external temperature and the water temperature of supply water.

<First Embodiment>
As shown in FIG. 1, the hot water supply apparatus 1 according to this embodiment includes a hot water storage tank 3, a heat pump heat source device (heating means) 7, and a control device 10 (FIG. 2).

  The hot water storage tank 3 is formed in a hollow cylindrical shape, for example. For example, a side surface of the hot water storage tank 3 has a plurality of temperature sensors T1 for detecting the temperature of the hot water in the hot water storage tank 3 (that is, hot water heated by the heat pump heat source device 7) or hot water (that is, water or medium / low temperature hot water). ~ T5 are arranged at an interval from the upper part to the lower part of the hot water storage tank 3.

  A hot water outlet 3a is provided at the upper part (for example, the ceiling) of the hot water storage tank 3, and a hot water heater (not shown) such as a currant is connected to the hot water outlet 3a through a hot water supply pipe h1. . A water supply port 3b is provided at the lower part (for example, the bottom) of the hot water storage tank 3, and a water supply pipe h2 for supplying supply water (for example, tap water) to the hot water storage tank 3 is connected to the water supply port 3b. ing. A discharge port 3c is provided at the lower part (for example, the bottom) of the hot water storage tank 3, and a pipe h3a from the inlet 7g of the heat pump heat source unit 7 is connected to the discharge port 3c. A hot water inlet 3d is provided at the upper part (for example, the side surface of the upper part) of the hot water storage tank 3, and a pipe h3b from the hot water outlet 7h of the heat pump heat source unit 7 is connected to the hot water inlet 3d.

  The pipe h3a is provided with a pump P1 for circulating hot water discharged from the discharge port 3c to the heat pump heat source unit 7 (more specifically, a heat exchanger 7c described later). The pump P1 may be disposed in the pipe h3b. The pipe h3b is provided with a temperature sensor T6 for detecting the temperature of hot water discharged from the hot water outlet 7h of the heat pump heat source unit 7. The pipe h3a has hot water flowing into the inlet 7g of the heat pump heat source unit 7. A temperature sensor T7 for detecting the temperature of is provided.

  The heat pump heat source unit 7 heats hot water flowing in from the inflow port 7g to a target temperature by heat exchange by a refrigeration cycle and discharges the hot water from the hot water outlet 7h. The heat pump heat source unit 7 includes, for example, a compressor 7b, a heat exchanger 7c, an expansion valve 7d, an evaporator 7e, a muffler 7f, and one or more (here, one) temperature sensors that detect the outside air temperature. 7a.

  The evaporator 7e is provided with a fan 7g for adjusting the capacity of the evaporator 7e. The temperature sensor 7 a is disposed inside or on the outer periphery of the heat pump heat source apparatus 7. In the case where there are a plurality of temperature sensors 7a, the temperature sensors 7a are distributed in the heat pump heat source unit 7 and / or the outer periphery thereof.

  The compressor 7b and the inlet 7i of the heat exchanger 7c are connected to each other via a discharge pipe h4. The outlet 7j and the expansion valve 7d of the heat exchanger 7c are connected to each other via the refrigerant path h5. The expansion valve 7d and the evaporator 7e are connected to each other via the refrigerant path h6. The evaporator 7e and the muffler 7f are connected to each other via the refrigerant path h7. The muffler 7f and the compressor 7b are connected to each other via a refrigerant path h8. As described above, the inlet 7g of the heat exchanger 7c is connected to the discharge port 3c of the hot water storage tank 3c via the pipe h3a, and the hot water outlet 7h of the heat exchanger 7c is hot water stored via the pipe h3b. It is connected to the hot water inlet 3d of the tank 3c.

  In the heat pump heat source device 7, the heating medium (hereinafter referred to as a medium) is compressed by the compressor 7b to be a high temperature. In the heat exchanger 7c, the hot medium from the compressor 7b flows in from the inlet 7i and flows out from the outlet 7j, and hot water from the hot water storage tank 3 flows in from the inlet 7g and flows out from the outlet 7h. At that time, the hot water is heated by the medium by performing heat exchange between the medium and the hot water. The expansion valve 7d expands and depressurizes the medium from the outlet 7j of the heat exchanger 3, and the evaporator 7e absorbs the surrounding heat and evaporates to be sent to the muffler 7f. The muffler 7f is sent to the compressor 7b. By repeating this cycle, the hot water flowing in from the inlet 7g is heated to the target temperature and discharged from the outlet 7h in the heat exchanger 7c. In this embodiment, the target temperature is adjusted by adjusting the drainage amount of the pump P1 by the control device 10. Here, a well-known heat pump heat source machine is used.

  As shown in FIG. 2, the control device 10 includes a remaining hot water amount detection unit 10a, a determination unit 10b, a water temperature detection unit 10c, a target temperature setting unit 10d, a rated capacity setting unit 10e, and a determination unit (determination unit) 10f. And a control unit (control means) 10g and an operation input unit 10h.

  The remaining hot water amount detection unit 10a detects the amount of hot water stored in the hot water storage tank 3 (remaining hot water amount) based on the detected temperatures of the temperature sensors T1 to T5. For example, when the detected temperature of each temperature sensor T1 to T3 is a high temperature of 90 ° C. and the detected temperature of each temperature sensor T4 to T5 is a low temperature of 40 ° C., the remaining hot water amount detection unit 10 It is detected that the amount is from the ceiling of the tank 3 to the position of the temperature sensor T3.

  Based on the detection result of the remaining hot water amount detection unit 10a, the determination unit 10b determines whether or not the remaining hot water amount in the hot water storage tank 3 is less than or equal to the activated remaining hot water amount, and whether or not the remaining hot water amount in the hot water storage tank 3 is greater than or equal to the stopped remaining hot water amount. Determine whether.

  The water temperature detection unit 10c detects, for example, the temperature of the supplied water supplied to the hot water storage tank 3 based on the outside air temperature. The outside air temperature detection unit (outside air temperature detection unit) 10i and the processing unit (processing unit). 10j.

  The outside air temperature detection unit 10i determines whether or not the heat pump heat source unit 7 has performed the heating operation for a predetermined time, and when the heat pump heat source unit 7 has not performed the heating operation for the predetermined time, for example, the temperature sensor 7a periodically A detected value is acquired, and the latest detected value is set as the outside air temperature. When there are a plurality of temperature sensors 7a, the outside air temperature is obtained as an average value from the detected values. The processing unit 10j obtains the water temperature of the supply water from the outside air temperature obtained by the outside air temperature detection unit 10i based on the correspondence between the outside air temperature and the water temperature of the feed water. The correspondence relationship is set by, for example, a correspondence table or an arithmetic expression. FIG. 7 is a graph showing an example of a correspondence relationship between the outside air temperature and the water temperature of the supply water.

  In the target temperature setting unit 10d, a target temperature of hot water discharged from the hot water outlet 7i of the heat exchanger 7c is set. This target temperature is set to be changeable by operating the operation input unit 10h, for example.

  In the rated capacity setting unit 10e, the rated capacity of the heating capacity of the heat pump heat source machine 7 is set as a fixed value, for example. In this hot water supply device 1, when the temperature of hot water flowing into the inlet 7g of the heat pump heat source unit 7 is the same as the temperature of the supply water (for example, tap water) from the supply pipe h2, the heat pump heat source unit 7 is rated. The heat pump heat source unit 7 is designed so as to exhibit the rated capacity set in the capacity setting unit 10e. More specifically, the water temperature of the supply water from the water supply pipe h2 changes according to the change in the outside air temperature, but the heat pump heat source machine 7 seems to exhibit the rated capacity for each water temperature of the supply water according to the outside air temperature. Therefore, even if the outside air temperature and the temperature of the supply water change accordingly, the temperature of the hot water flowing into the inlet 7g of the heat pump heat source machine 7 is the same as that of the supply water (for example, tap water) from the water supply pipe h2. If it is the same as the water temperature, the rated capacity will be demonstrated.

  The determination unit 10f determines the amount of drainage g of the pump P1 in a stable state of the heating operation when hot water flowing into the inlet 7g of the heat pump heat source unit 7 is heated to the target temperature by the heat pump heat source unit 7. As will be described later, the amount of discharged water g (unit: l (liter) / min) is the water temperature Ti (unit: ° C.) of the supply water supplied from the water supply pipe h2, and the hot water discharged from the outlet 7h of the heat pump heat source unit 7. From the target temperature To (unit: ° C.), the rated capacity Q (unit: W) of the heating capacity of the heat pump heat source unit 7 and the specific heat Cp of water (for example, 4200 [J (joule) / l / ° C.)) Is required. Therefore, the determination unit 10d, for example, at the start of the heating operation of the heat pump heat source device 7, the water temperature Ti of the supply water detected by the water temperature detection unit 10c, the target temperature To set in the target temperature setting unit 10d, and the rated capacity setting The drainage amount g is determined based on Equation 1 from the rated capacity Q set in the part 10e.

  In Equation 1, “/” is division and “*” is multiplication. For example, when Ti = 10 [° C.], To = 70 [° C.], and Q = 4500 [W], g = 1.07 [l / min].

  Control unit 10g heats the hot water in hot water storage tank 3 based on the determination result of determination unit 10b. More specifically, when the remaining hot water amount in the hot water storage tank 3 is equal to or less than the activated residual hot water amount as a result of determination by the determination unit 10b, the control unit 10g operates the heat pump heat source unit 7 and the pump P1 to Heat the hot water. More specifically, the control unit 10g controls the heat pump heat source unit 7 to start the heating operation of the heat pump heat source unit 7, and from the drainage amount g determined by the determination unit 10f based on Equation 2, the flow rate instruction value q And the pump P1 is operated based on the flow rate instruction value q.

  For example, when a = 1, b = 0 [l / min], and g = 1.08 [l / min], q = 1.08 [l / min].

  Thus, the hot water in the hot water storage tank 3 is circulated in the order of 3e → P1 → 7c → 3d and heated by the heat exchanger 7c, whereby the hot water in the hot water storage tank 3 is heated to the target temperature. At that time, from the start of the heating operation of the hot water in the hot water storage tank 3, the pump P1 is operated with a drainage amount g in a stable state of the heating operation.

  In addition, after a certain time has elapsed from the start of the heating operation of the heat pump heat source unit 7, the control unit 10g is configured so that the temperature of the hot water discharged from the hot water outlet 7h becomes the target temperature based on the detection value of the temperature sensor T6. The discharge amount of the pump P1 is feedback-controlled. That is, the control unit 10g increases the discharge amount of the pump P1 when the detection value of the temperature sensor T6 is higher than the target temperature, and reduces the discharge amount of the pump P1 when the detection value of the temperature sensor T6 is lower than the target temperature. Let

  Moreover, the control part 10g controls the heat pump heat source unit 7 so that the heating capability of the heat pump heat source unit 7 is kept constant with respect to changes in the outside air temperature. More specifically, since the heating capability of the heat pump heat source device 7 decreases as the outside air temperature decreases, the control unit 10g increases the operating frequency of the compressor 7b as the detection value of the temperature sensor 7a decreases, and the temperature sensor 7a. The higher the detected value is, the lower the operating frequency of the compressor 7b is, and the heating capacity of the heat pump heat source unit 7 is kept constant.

  In addition, when the remaining hot water amount in the hot water storage tank 3 is equal to or greater than the stopped remaining hot water amount, the control unit 10g stops the heat pump heat source unit 7 and the pump P1 to stop heating the hot water in the hot water storage tank 3.

  In this embodiment, as described above, at the start of the heating operation of the heat pump heat source unit 7, the pump P1 is operated with the amount of drainage of the pump P1 in the stable state of the heating operation of the heat pump heat source unit 7. The amount of drainage g of the pump P1 in a stable state of the heating operation of the heat pump heat source unit 7 is expressed by Equation 1 (that is, the rated capacity of the heat pump heat source unit 7, the temperature of the supply water (tap water) supplied to the hot water storage tank 3, and the heat pump heat source unit). The reason why it is obtained using the target temperature of hot water discharged from the 7 hot water outlet 7h is as follows.

  The heat pump heat source unit 7 is maintained in a stable state by feedback control after it has been in a stable state after starting the heating operation, but when the heat pump heat source unit 7 starts the heating operation, the control unit If the flow rate instruction value q (that is, the amount of drainage of the pump P1 at the start of the heating operation of the heat pump heat source device 7) initially given from 10 g to the pump P1 is not appropriate, the heating operation of the heat pump heat source device 7 transitions to a stable state. In a transient state in the process, a phenomenon occurs in which the pressure of the refrigerant path in the heat pump heat source unit 7 increases excessively or the temperature of hot water flowing out of the heat pump heat source unit 7 becomes unstable.

  However, when the heating operation of the heat pump heat source apparatus 7 is started, if the value at the time of stable heating operation can be given to the flow rate instruction value q first instructed to the pump P1 (that is, the pump P1 is stable when the heating operation is stable). If the pump P1 can be operated with the drainage amount), the stable flow rate instruction value q is the stable flow rate instruction value q finally reached through the transient state, and therefore the pressure in the refrigerant path in the transient state is It is possible to prevent a phenomenon in which the temperature rises excessively or the temperature of hot water flowing out from the outlet 7h of the heat pump heat source device 7 becomes unstable.

  Here, the flow rate indication value at the time of stability (that is, the amount of drainage of the pump P1 at the time of stability = the flow rate circulating through the heat pump heat source device 7 at the time of stability) is the heating capacity of the heat pump heat source device 7 at the time of stability. It can be calculated by the temperature difference between the temperature of hot water flowing out from 7h and the temperature of hot water flowing into the inlet 7g of the heat pump heat source unit 7 and the specific heat of water. However, heat pumps other than the specific heat of water (this specific heat is a substantially fixed value due to physical properties) and the temperature of hot water flowing out from the outlet 7h of the heat pump heat source unit 7 (this temperature is controlled to the target temperature, so it is a fixed value when stable). The heating capacity of the heat source unit 7 and the temperature of the hot water flowing into the inlet 7g of the heat pump heat source unit 7 are variable values and are not independent as parameters (for example, depending on the temperature of the hot water flowing into the inlet 7g of the heat pump heat source unit 7 Therefore, the process of estimating the flow rate instruction value at the time of stability (that is, the amount of drainage of the pump P1 at the time of stability) is complicated, and the estimation process is burdened.

  On the other hand, this type of hot water supply device 1 that uses a refrigeration cycle heats the heat pump heat source device 7 when the temperature of the hot water flowing into the inlet 7g of the heat pump heat source device 7 rises due to its nature. However, the flow rate of the hot water circulating through the heat pump heat source unit 7 has a characteristic that it does not change substantially. That is, the hot water circulating at the heat pump heat source unit 7 in a state where the hot pump water having a temperature that exhibits the heating capability of the rated capability flows into the inlet 7g of the heat pump heat source unit 7 and the heat pump heat source unit 7 is operating at the rated capability. Even if the temperature of the hot water flowing into the inlet 7g of the heat pump heat source apparatus 7 rises from that state and the heating capacity decreases, the flow rate hardly changes.

  The above characteristics can be understood from the following consideration. That is, in the heat exchanger 7c, heat exchange was performed between the hot water flowing in from the inlet 7g and flowing out from the outlet 7h and the heating medium flowing in from the inlet 7i and discharged from the outlet 7j. In this case, the amount of heat Q1 obtained by the hot water and the amount of heat Q2 lost by the heating medium are given by Equation 3 and Equation 4, respectively.

  In Equation 3, gw is the flow rate of hot water, cp is the specific heat of water, and Δt is the temperature tw, in when flowing into the inflow port 7g of hot water and when flowing out from the outlet port 7h. It is a temperature difference (tw, out-tw, in) from the temperature tw, out. In Equation 4, gr is the flow rate of the heating medium, and Δh is the difference between the enthalpy hin when the heating medium flows into the inlet 7i and the enthalpy hout when it flows out from the outlet 7j (hin− hout).

  The respective heat quantities Q1 and Q2 are equal to each other (that is, Q1 = Q2), and Expression 5 is obtained from this relationship. Considering the case where gr is constant, the relationship of Equation 5 to Equation 6 (that is, the relationship that gr is proportional to Δh / Δt) is obtained.

  Usually, the temperature tr, out of the heating medium flowing out from the outlet 7j (that is, the heating medium after heat exchange) is higher than the temperature tw, in of hot water flowing into the inlet 7g (that is, hot water before heat exchange). high. Therefore, as shown in FIG. 4, when the temperature tw, in flowing into the inlet 7g rises (that is, when Δt decreases), the temperature tr, out of the heating medium flowing out from the outlet 7j also rises. As a result, the enthalpy hout of the heating medium flowing out from the outlet 7j also increases (that is, Δh becomes smaller). At that time (that is, when tw, in rises), Δh and Δt change at substantially the same rate (that is, Δh / Δt becomes substantially constant). This characteristic can be understood from FIGS. 5 and 6, for example.

  FIG. 5 shows, for example, values of performance measurement standard conditions tw, in, tw, out, tr, out, Δt, Δh, Δh / Δt of JRA4050 (Japan Refrigeration and Air Conditioning Industry Association Standard Regulation “House Heat Pump Water Heater”) Is shown. This is the ratio of Δh / Δh in the case of each value of tw, in when Δh / Δh when tw, in = 9 ° C. is used as a reference. FIG. 6 shows values of tw, in, tw, out, tr, out, Δt, Δh, and Δh / Δt when hot water is heated at a target temperature of 65 ° C. in the intermediate period. 5 and 6, it can be seen that Δh / Δt is substantially constant with increasing tw, in.

  The heat pump heat source device 7 of this type of hot water supply apparatus 1 is generally placed outdoors (that is, exposed to the outside air), and tap water is generally supplied to the hot water storage tank 3 as supply water. Therefore, the rated capacity of the heat pump heat source unit 7 is such that water at the temperature of the water that will be supplied to the hot water storage tank 3 in a certain outside air (tap water temperature in the outside air) flows into the inlet 7g of the heat pump heat source unit 7. (For example, when the dry bulb temperature, wet bulb temperature, and inflow water temperature of JRA4050 are measured, 4.5kW appears as the rated capacity of the heat pump heat source unit 7) Set to do). In other words, if hot water having the same temperature as tap water flows into the inlet 7g of the heat pump heat source unit 7 during the heating operation, the heat pump heat source unit 7 can output the rated capacity (this rated capacity ( Fixed value), the temperature of hot water flowing into the inlet 7g (ie, the temperature of tap water), the temperature of hot water flowing out of the outlet 7h (target temperature, fixed value), and the specific heat of water (almost fixed value) Thus, the flow rate of hot water circulating through the heat pump heat source unit 7 can be calculated when the heating operation is stable.

  This calculation is performed on the assumption that hot water having the same temperature as the tap water temperature flows into the inflow port 7g of the heat pump heat source unit 7. However, even if the temperature of the flowing hot water rises as described above, the heat pump heat source unit 7 is changed. Considering that the circulating flow rate hardly changes, even if the actual temperature at the start of the heating operation of the hot water flowing into the inlet 7g of the heat pump heat source unit 7 is higher than the temperature of the tap water, the flowing hot water The calculated flow rate can be regarded as the flow rate when the heating operation is stable. In other words, the flow rate of hot water circulating through the heat pump heat source unit 7 when the heating operation of the heat pump heat source unit 7 is stable when hot water having a temperature higher than the tap water temperature flows into the inlet 7g of the heat pump heat source unit 7 is It can be considered that it is the same as the flow rate of the hot water circulating through the heat pump heat source unit 7 when the heating operation of the heat pump heat source unit 7 is stable when hot water having the same temperature as the tap water flows into the inlet 7 g of the heat pump heat source unit 7.

  In consideration of these matters, in this embodiment, the rated capacity of the heat pump heat source unit 7 and the supply water supplied to the hot water storage tank 3 regardless of the actual temperature of the hot water flowing into the inlet 7 g of the heat pump heat source unit 7. The amount of drainage of the pump P1 when the heating operation of the heat pump heat source unit 7 is stable, using the temperature of (tap water) and the target temperature of the hot water discharged from the outlet port 7h of the heat pump heat source unit 7 (ie, using Equation 1) Is required.

  According to the hot water supply apparatus 1 configured as described above, the amount of drainage of the pump P1 at the start of the heating operation of the heat pump heat source unit 7 can be obtained from the amount of drainage of the pump P1 in the stable state of the heating operation (that is, Equation 1). Therefore, when the heating operation of the heat pump heat source device 7 is started, the flow rate of hot water flowing into the inlet 7g of the heat pump heat source device 7 is set to an appropriate flow rate (that is, the heating operation of the heat pump heat source device 7). The amount of drainage of the pump P1 in a stable state, in other words, the flow rate at which hunting or the like does not occur).

  Moreover, since the rated capacity (that is, a fixed value) of the heat pump heat source apparatus 7 is used for calculating an appropriate flow rate, the processing load of the calculation can be reduced.

  Moreover, according to this hot water supply device 1, the temperature of the hot water flowing into the heat pump heat source unit 7 and the temperature at which the heat pump heat source unit 7 exhibits the rated capacity is used as the temperature of the supplied water detected by the water temperature detection unit 10c. Yes. When heating water having the same water temperature as the supply water, the heat pump heat source unit 7 exhibits the rated capacity, but the water temperature of the supply water changes according to environmental conditions (for example, the outside air temperature). Therefore, by using the water temperature detection unit 10c that detects the water temperature of the supplied water, the water temperature at which the heat pump heat source device 7 at that time exhibits the rated capacity is always detected even if the environmental conditions (for example, the outside air temperature) change. Is possible. Thereby, even if environmental conditions (for example, external temperature) change, it becomes possible to determine an appropriate amount of drainage using the rated capacity of the heat pump heat source unit 7.

  In this embodiment, when the water temperature of the supply water (tap water) is detected based on the outside air temperature, the detection value of the temperature sensor 7a provided in the heat pump heat source unit 7 is used as the outside air temperature. However, this is not a limitation. As long as the temperature sensor detects the outside air temperature, the detection value of any temperature sensor may be used.

  Further, since the flow rate instruction value q is a linear function of the drainage amount g, the flow rate instruction amount q can be determined so that the fluctuation of the drainage amount g is linearly reflected.

Second Embodiment
In the first embodiment, the temperature of the supplied water is detected based on the outside air temperature. In this embodiment, the temperature of the supplied water is detected based on a temperature sensor T5 disposed in the lower part of the hot water storage tank 3. Hereinafter, based on FIG. 3, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and different parts will be mainly described.

  In the hot water supply apparatus 1B according to this embodiment, the water temperature detection unit 10cB includes a temperature sensor T5 disposed in the lower part of the hot water storage tank 3 and a temperature detected by the temperature sensor T5 within a predetermined time as shown in FIG. The processing part 10jB which determines the minimum temperature of them as the water temperature of supply water is provided.

  Here, as the temperature sensor T5 of the water temperature detection unit 10cB, an existing temperature sensor T5 disposed under the hot water storage tank 3 in order to detect the remaining hot water amount of the hot water storage tank 3 is used. When the hot water in the hot water storage tank 3 is heated, supply water or low / medium temperature water is accumulated in the lower part of the hot water storage tank 3 and every time hot water is discharged from the hot water outlet 3a of the hot water storage tank 3, the water supply port 3b of the hot water storage tank 3 is supplied. Since the supply water is supplied from below and the supply water accumulates in the lower part of the hot water storage tank 3, as described above, the lowest temperature of the temperatures detected by the temperature sensor T5 within a predetermined time is determined as the water temperature of the supply water. Thus, the probability that the detected value of the temperature sensor T5 is the temperature of the feed water is increased.

  Since the other configuration of this embodiment is the same as that of the first embodiment, description thereof is omitted.

  According to the hot water supply apparatus 1B configured as described above, since there is a high possibility that the supply water is accumulated in the lower part of the hot water storage tank 3, the temperature sensor (that is, the existing temperature) disposed in the lower part of the hot water storage tank 3 is used. By using the sensor T5, the temperature of the supplied water can be detected at low cost.

  In this embodiment, the temperature of the feed water is detected using the existing temperature sensor T5. However, a temperature sensor for detecting the temperature of the feed water is provided in the water suction pipe h2, and the temperature sensor is used. The temperature of the feed water may be detected. In this way, the temperature of the feed water can be detected more accurately.

DESCRIPTION OF SYMBOLS 1,1B Hot-water supply apparatus 3 Hot water storage tank 3a Hot water outlet 3b Water supply port T1-T7, 7a Temperature sensor 7 Heat pump heat source machine 7b Compressor 7c Heat exchanger 7d Expansion valve 7e Evaporator P1 Pump 10c, 10cB Water temperature detection part 10i External temperature detection Unit 10j processing unit 10g control unit 10f determination unit

Claims (7)

A hot water storage tank (3),
Heating means (7) for heating the hot water in the hot water storage tank by heat exchange by a refrigeration cycle;
A pump (P1) for circulating hot water in the hot water tank through the heating means and returning the hot water to the hot water tank;
Control means (10g) for controlling the amount of drainage of the pump so that hot water flowing into the heating means flows out at a target temperature;
Based on the value obtained by dividing the rated capacity of the heating means by the temperature difference between the water temperature flowing into the heating means and the water temperature at which the heating means exhibits the rated capacity and the target temperature, Determining means (10f) for determining the amount of drainage of the pump;
With
The said control means (10g) controls the drainage amount of the said pump at the time of the start of the heating operation of the said heating means so that it may become the drainage amount determined by the said determination means (10f). The hot water supply device according to claim 1,
Water temperature detecting means (10c, 10cB) for detecting the temperature of the supplied water supplied to the hot water storage tank;
The determining means (10f)
The hot water supply apparatus using the water temperature of the supplied water detected by the water temperature detecting means as the water temperature of the water flowing into the heating means and the water temperature at which the heating means exhibits the rated capacity. The hot water supply device according to claim 2,
The water temperature detecting means (10c)
An outside air temperature detecting means (10i) for detecting the outside air temperature;
Processing means (10j) for determining the water temperature of the supply water from the outside air temperature detected by the outside air temperature detection means based on the correspondence relationship between the outside air temperature and the water temperature of the supply water;
A hot water supply apparatus comprising: The hot water supply device according to claim 3,
The heating means (7) is provided with one or more temperature sensors (7a),
The outside air temperature detecting means (10i)
A hot water supply apparatus, wherein an outside air temperature is obtained from one or a plurality of detected values of the one or more temperature sensors when the heating means has not performed a heating operation for a predetermined time. The hot water supply device according to claim 2,
The water temperature detection means (10cB)
A temperature sensor (T5) disposed in a lower portion of the hot water storage tank (3);
Processing means (10jB) for determining the lowest temperature among the temperatures detected within a predetermined time by the temperature sensor as the water temperature of the supply water;
A hot water supply apparatus comprising: A hot water supply apparatus according to any one of claims 1 to 5,
The control means (10g) determines a flow rate instruction value based on the amount of drainage determined by the determination means, and based on the flow rate instruction value, the pump at the start of the heating operation of the heating means (7). Control the amount of drainage,
The hot water supply apparatus, wherein the flow rate instruction value is a linear function of the drainage amount. The hot water supply device according to any one of claims 1 to 6,
The heating means (7)
A compressor (7b) for compressing the heating medium;
A heat exchanger (7c) for performing heat exchange between the heating medium compressed by the compressor and hot water from the hot water storage tank (3) to heat the hot water with the heating medium;
An expansion valve (7d) for depressurizing the heating medium flowing out of the heat exchanger;
An evaporator (7e) for evaporating the heating medium decompressed by the expansion valve;
A hot water supply apparatus comprising:

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