JP2005345099A - Heat pump hot-water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely make prevention of hot-water shortage and energy saving performance compatible in a heat pump hot-water supply device. <P>SOLUTION: This heat pump hot-water supply device wherein a heat pump heating means 1 provided with a capacity variable compressor 11 is connected to a hot-water storage tank 21 is provided with an outside air temperature detecting means 3 for detecting an outside air temperature, a clocking means for detecting a time, and a control means 5 for changing an operation frequency of the compressor 11, based on both the outside air temperature detected by the outside air temperature detecting means 3 and a time zone in one day. An unbalance between a hot-water supply and a heating-up capacity of the heat pump heating means 1 is eliminated as much as possible, by this constitution, and the heat pump heating means 1 is thereby precluded from being operated with the heating-up capacity exceeding a required level to realize an energy saving operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat pump water heater using a heat pump heating means as a means for heating water.

  Conventionally, heat pump water heaters using a refrigerant circulation heat pump as a heat source have been proposed in various structures (for example, Japanese Patent Application Laid-Open No. 60-221661 (first known example), Japanese Patent Application Laid-Open No. Sho). No. 61-153429 (second known example), Japanese Patent Laid-Open No. 9-68369 (third known example)).

  In a heat pump hot water supply apparatus, as a hot water storage tank, a normally full tank that always keeps hot water or hot water and water in a full tank state is adopted. In addition, as a heating method for the water supply, the water supply is directly introduced into the heat exchanger of the heat pump, the hot water obtained by the heat exchange here is stored in a hot water storage tank, and the hot water is discharged as needed. A method of supplying hot water and circulating water between the hot water storage tank and a heat exchanger of the heat pump to obtain hot water, or a heating heat exchanger that constitutes a refrigerant circulation system with the heat exchanger on the heat pump side Various systems have been proposed, such as a system in which water is disposed in a tank and water supplied to the hot water storage tank is indirectly heated by the heating heat exchanger.

  In the heat pump hot water supply device, when the amount of hot water in the hot water storage tank decreases below a predetermined value (that is, when the ratio of hot water in the hot water storage tank decreases below a predetermined value), the hot water runs out (that is, the ratio of hot water is close to zero). Next, it is necessary to perform “refreshing” in order to prevent the low temperature water from occupying the hot water storage tank. In addition, in the “additional cooking” referred to here, newly obtained hot water is additionally introduced into the hot water storage tank corresponding to each of the above heating methods to recover the hot water storage amount (that is, hot water in the hot water storage tank is recovered). It is a concept that includes both a mode in which the ratio is increased) and a mode in which hot water or water in the hot water storage tank is additionally heated to increase the hot water temperature to recover the hot water storage amount.

  By the way, the heat pump used as a heat source for supplying water has a characteristic that its ability depends on the outside air temperature, and this characteristic does not correspond to the hot water supply load (that is, the amount of hot water used). That is, FIG. 5 shows a change state of the “cooking ability” with respect to the outside air temperature and a change state of the hot water supply load with respect to the outside air temperature when the compressor of the heat pump is continuously operated at a constant rotation for 1 hour. Here, the “cooking ability” of the heat pump tends to decrease as the outside air temperature decreases, whereas the hot water supply load tends to increase as the outside air temperature decreases. Therefore, in winter when the outside air temperature is low, the heat-cooking ability of the heat pump is low despite the large hot water supply load. It is. On the other hand, in summer when the outside air temperature is high, the “cooking ability” of the heat pump is high even though the hot water supply load is small, so that there is a sufficient margin for “additional cooking”. In addition, in FIG. 6, the change state with respect to the outside temperature of the "boiled hot water amount" by a heat pump is shown, and it becomes a characteristic corresponding to the "cooking ability" of FIG.

  On the other hand, the hot water supply load varies greatly depending on the time period of the day. That is, FIG. 7 shows a change state of the hot water supply load according to the time zone when the outside air temperature is low as in winter, and FIG. 10 shows a change state according to the time zone of the hot water supply load when the outside temperature is high as in summer. Show. From FIG. 7 and FIG. 10, the change state of the hot water supply load in the time zone of the day is almost the same in winter and summer without being influenced by the level of the outside temperature, and the breakfast time in the day The hot water supply load is concentrated in the time zone from 6 to 8 o'clock, the time zone from 10 o'clock to 13 o'clock in the lunch time zone, and from 18 o'clock to 24 o'clock in the dinner and bathing time zone, In particular, it can be seen that the hot water supply load reaches a peak in the bathing time zone from 19:00 to 20:00.

  Here, as described above, the “cooking ability” of the heat pump depends on the outside air temperature, and decreases as the outside air temperature is low. Therefore, in winter when the outside air temperature is low, as shown in FIG. Even if the heat pump is operated at the maximum heating amount for 3 hours in the time zone from 18:00 to 21:00 near the peak, the remaining amount of hot water in the hot water storage tank remains small as shown in FIG. However, it will be in the state which hardly increases. In addition, if the heat pump is operated at the maximum heating amount between 23:00 and 3 o'clock, the amount of remaining hot water will remain almost full despite the increase in the amount of hot water used during breakfast and lunch hours. become.

  On the other hand, in the summer when the outside air temperature is high, as shown in FIG. 11, the heat pump is operated only for 1 hour at the maximum heating amount in the time zone from 18:00 to 21:00 in the vicinity of the hot water supply load reaching the peak. However, as shown in FIG. 12, the amount of hot water remaining in the hot water storage tank remains small enough not to cause hot water shortage, and if the heat pump is operated at the maximum heating amount between 23:00 and 24:00, Despite the increase in the amount of hot water used during lunch hours, the amount of remaining hot water will remain almost full.

  From the above, it can be said that in the operation control of the heat pump hot water supply apparatus, it is necessary to consider the time zone of the day as well as the outside air temperature.

  Furthermore, when controlling the operation of the heat pump water heater, it is necessary to consider the operating efficiency of the heat pump. That is, as shown in FIG. 4, it is known that the operating efficiency of the heat pump changes in accordance with the operating frequency of the compressor. The operating efficiency exhibits a peak value at a specific operating frequency “a”, and the operating efficiency decreases as the operating frequency deviates from the operating frequency “a”. On the other hand, it is known that the capacity of the heat pump (cooking capacity) tends to increase with an increase in the power factor as the operating frequency of the compressor increases.

  Therefore, in order to achieve energy saving by operating the heat pump water heater without running out of hot water and with higher efficiency, capacity adjustment by changing the operating frequency of the compressor will affect the cooking capacity. It can be said that it is necessary to consider both the outside temperature to be given and the time zone of the day.

  However, in each of the heat pump water heaters of the above-mentioned known examples, although the capacity of the compressor is variable, the capacity change is performed based only on the outside temperature (first known example), the hot water in the hot water storage tank What is performed based on the temperature (second known example), what is performed based on both the hot water temperature in the hot water storage tank and the time zone of the day (third known example), and the outside temperature and the time of the day It was not carried out based on both of the bands. Therefore, in any of these, dissatisfaction remained in terms of both prevention of running out of hot water and energy saving.

  Accordingly, the present invention has been made for the purpose of providing a heat pump hot water supply apparatus that more reliably achieves both hot water prevention and energy saving.

  In the present invention, the following configuration is adopted as a specific means for solving such a problem.

  In the first invention of the present application, in the heat pump hot water supply apparatus configured by connecting the heat pump heating means 1 including the compressor 11 whose capacity is variable based on the operating frequency and the hot water storage tank 21 by piping, the outside air temperature is set. The operating frequency of the compressor 11 is changed based on both the outside air temperature detecting means 3 for detecting, the time measuring means 4 for detecting the time, and the outside air temperature detected by the outside air temperature detecting means 3 and the time zone of the day. The control means 5 is provided.

  In the second invention of the present application, in the heat pump hot water supply apparatus according to the first invention, the control means 5 operates the compressor 11 at a first frequency at which high efficiency is obtained in the night time zone. It is a feature.

  In the third invention of the present application, in the heat pump hot water supply apparatus according to the first invention, the control means 5 changes and sets the operating frequency of the compressor 11 in accordance with the outside air temperature during the daytime period. It is said.

  According to a fourth invention of the present application, in the heat pump hot water supply apparatus according to the third invention, the compressor 11 has the first frequency at which high efficiency is obtained when the outside air temperature is high, and the first when the outside air temperature is low. It is characterized by operating at a second frequency that is higher than the first frequency.

  The fifth invention of the present application is characterized in that, in the heat pump hot water supply apparatus according to the first invention, the refrigerant circulating through the heat pump heating means 1 is a CO2 refrigerant.

  The sixth invention of the present application is characterized in that, in the heat pump hot water supply apparatus according to the first invention, the compressor 11 is a swing type compressor.

  In the present invention, the following effects can be obtained by adopting such a configuration.

  (1) According to the heat pump hot water supply apparatus according to the first invention of the present application, the heat pump heating means 1 including the compressor 11 whose capacity is variable based on the operating frequency and the hot water storage tank 21 are connected by piping. In the heat pump water heater to be used, the outside air temperature detecting means 3 for detecting the outside air temperature, the time measuring means 4 for detecting the time, and the outside air temperature detected by the outside air temperature detecting means 3 and the time zone of one day. And the control means 5 for changing the operating frequency of the compressor 11, the cooking capacity of the heat pump heating means 1 is greatly influenced by the outside air temperature, and the hot water supply load changes in the time zone of one day. Furthermore, since the operating efficiency of the heat pump heating means 1 varies depending on the operating frequency of the compressor, the operating frequency of the compressor 11 By changing on the basis of both the outside air temperature and the time of the day and selecting the operation mode between high efficiency operation and high capacity operation, the hot water supply load and the cooking capacity of the heat pump heating means 1 The unbalance is eliminated as much as possible, and the hot water caused by the unbalance is surely prevented, and the heat pump heating means 1 is not operated with the cooking capacity more than necessary, and the energy saving operation is realized. Will be.

  (2) According to the heat pump hot water supply apparatus according to the second invention of the present application, in the heat pump hot water supply apparatus according to the first invention, the nighttime period, that is, generally, the load for hot water supply is small and the time is relatively long. In the time zone in which hot water can be stored over time, the compressor 11 is operated at the first frequency at which high efficiency can be obtained. Therefore, the effect of realizing the energy saving operation in (1) is further promoted. Is.

  (3) According to the heat pump hot water supply apparatus according to the third invention of the present application, in the heat pump water heater according to the first invention, the hot water supply load is large compared to the daytime period, that is, the nighttime period, and it is said that hot water prevention is prevented. In the time zone when the demand is high, the operating frequency of the compressor 11, that is, the “cooking ability” of the heat pump heating means 1 is changed and set according to the outside air temperature that greatly affects the “cooking ability”. Therefore, the effect of preventing hot water shortage in the above (1) can be further ensured.

  In addition, when the hot water storage tank 21 is filled with high-temperature hot water at nighttime hours and at a lower nighttime electricity rate than the daytime time zone, it is sufficient to fill the tank in 8 hours at night. An energy-saving operation is realized by operating at the first operating frequency at which efficiency is obtained.

  (4) According to the heat pump hot water supply apparatus according to the fourth invention of the present application, in the heat pump hot water supply apparatus according to the third invention, the compressor 11 has the first frequency at which high efficiency is obtained when the outside air temperature is high. When the outside air temperature is low, the operation is performed at the second frequency higher than the first frequency. Therefore, when the outside air temperature is high, that is, the cooking capacity itself of the heat pump heating means 1 is When the compressor 11 is high, the hot water supply capacity is sufficient even when the compressor 11 is operated at high efficiency at the first frequency, and there is no risk of running out of hot water. When the outside air temperature is low, that is, when the heat pump heating means 1 is cooked. When the upper capacity itself is low, the compressor 11 is operated at the second frequency higher than the first frequency to increase the capacity, thereby preventing the occurrence of hot water out surely. It can be, as these synergistic, effect of preventing the hot water out of the (3) is crimped if more reliably.

  (5) According to the heat pump hot water supply apparatus according to the fifth invention of the present application, in the heat pump hot water supply apparatus according to the first invention, the refrigerant circulating through the heat pump heating means 1 is a CO2 refrigerant. Since it is a high-pressure refrigerant and has a high condensation temperature, hot water can be taken out and hot water can be easily supplied.

  (6) According to the heat pump hot water supply apparatus according to the sixth invention of the present application, in the heat pump hot water supply apparatus according to the first invention, since the compressor 11 is a swing type compressor, the swing type compressor includes For example, there is no problem such as that there is a limit to high-speed rotation from the viewpoint of lubricity like a rolling piston compressor, or there is a limit to low-speed rotation with a large leakage loss like a scroll compressor, The change width can be made larger, and as a result, the hot water prevention effect is further promoted by further increasing the cooking capacity of the heat pump heating means 1.

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

  In FIG. 1, the system diagram of the heat pump hot-water supply apparatus Z concerning embodiment of this invention is shown. This heat pump hot water supply apparatus Z is composed of a heat pump heating means 1 and hot water storage / hot water supply means 2 described below.

  The heat pump heating means 1 is composed of a compression refrigeration circuit, and is an electric compressor 11 whose capacity can be changed by selecting an operating frequency, and between the water supply functioning as a condenser. The water heat exchanger 12 that heats the feed water by heat exchange at the outlet, the decompression means 13 constituted by, for example, an expansion valve, and the air heat exchanger 14 that functions as an evaporator are sequentially connected in an annular manner by the refrigerant pipe 31 Configured.

  In this embodiment, a swing type compressor is adopted as the compressor 11 and a CO2 refrigerant is adopted as the refrigerant.

  The hot water storage / hot water supply means 2 includes a hot water storage tank 21 having a predetermined capacity, and a water pipe 34 is connected to the bottom surface side of the hot water storage tank 21 via a branch pipe 35. One end of the water pipe 34 is connected to a water supply source such as a water supply, the other end is connected to the water heat exchanger 12, and the water pipe 34 is at an intermediate position between the branch pipe 35 and the water heat exchanger 12. Is provided with a water pump 22.

  Further, a first hot water pipe 32 for storing hot water is provided between the water heat exchanger 12 and the hot water storage tank 21 and between the top of the hot water storage tank 21 and a hot water tap (not shown). Are connected by a second hot water pipe 33 for hot water supply. A first temperature detecting means TH1 is provided near the lower side of the side wall of the hot water storage tank 21, and a second temperature detecting means TH2 is provided near the upper side. The first temperature detecting means TH1 is for detecting that hot water of a predetermined temperature or higher is nearly full, and the second temperature detecting means TH2 is the minimum necessary to prevent hot water from running out. This is for detecting the presence or absence of a limited amount of hot water, and the detection signals of these temperature detection means TH1 and TH2 are respectively input to the controller 5 as operation control elements.

  The controller 5 corresponds to the “control means” in the claims, and controls the operation of the heat pump water heater Z. The controller 5 includes detection signals from the temperature detection means TH1 and TH2. In addition, the outside air temperature signal detected by the outside air temperature detecting means 3 and the current time detected by the time measuring means 4 are input, respectively, and a control signal is output to the compressor 11 based on these input signals. The operating frequency is appropriately changed and set.

  Hereinafter, the operation control of the heat pump water heater Z by the controller 5 will be described based on the flowchart shown in FIG.

  First, for the convenience of explanation, the basic concept of operation control by the controller 5 will be described based on the map shown in FIG. In this embodiment, first, in consideration of the influence of the outside air temperature on the cooking capacity of the heat pump heating means 1, the use environment of the heat pump hot water supply device Z is set to an environment where the outside air temperature is low such as in winter when the cooking capacity is low. And the environment with high outside air temperature such as summer when cooking capacity is high. Furthermore, taking into account that the hot water supply load for the heat pump hot water supply device Z varies depending on the time of the day, 24 hours a day are divided into daytime hours (7:00 to 23:00) with a high hot water supply load and night hours with a low hot water supply load. It is divided into bands (23: 00-7pm).

And according to this division,
(E1) In the daytime hours when the outside air temperature is low, the hot water supply load is high even though the cooking capacity of the heat pump heating means 1 is low. When it is necessary to increase capacity,
(Low 1) In the daytime hours when the outside air temperature is high, the heating capacity of the heat pump heating means 1 is low even though the cooking capacity is high. This is where energy conservation should be emphasized.
(Har 1) At night, the hot water supply load is low both when the outside air temperature is high and low, and there is sufficient time for cooking. Therefore, energy saving by high-efficiency operation should be emphasized. is there.

From this point of view, in this embodiment, the operating frequency of the compressor 11 is
(E2) In the daytime time zone when the outside air temperature is low, the point B in FIG. 4, that is, the operating frequency “b” at which the increase in the capacity of the heat pump heating means 1 can be expected although the operating efficiency is somewhat reduced,
(Low 2) In the daytime time zone when the outside air temperature is high, set the point A in FIG. 4, that is, the driving frequency “a” having the highest driving efficiency,
(Har 2) At night, regardless of the outside air temperature, the point A in FIG. 4, that is, the operation frequency “a” having the highest operation efficiency is set.

  By such setting control of the operating frequency, the heat pump hot water supply device Z can be prevented from running out of heat and achieve both energy saving operation.

  Here, based on the flowchart of FIG. 2, the operation control by the said controller 5 is demonstrated concretely.

  After the start of control, first, in step S1, it is determined whether or not the present day is a daytime time zone. Here, if it is determined that it is not the daytime period, that is, it is the nighttime period, whether or not the detected value of the first temperature detection means TH1 is 60 ° C. or higher in step S2 (that is, the current high temperature). Whether or not the hot water is in a full tank state) is determined, and if it is 60 ° C. or higher (that is, if it is in a full tank state), no further hot water storage is required, so the operation of the heat pump water heater Z is stopped. (Step S11). On the other hand, when the temperature is 60 ° C. or lower, the operation of the heat pump hot water supply device Z is started to increase the amount of stored hot water (step S3). The operation frequency of 11 is set to a high efficiency point (that is, point A in FIG. 4), and high efficiency operation is performed.

  On the other hand, if it is determined in step S1 that it is currently in the daytime time zone, it is further determined in step S4 whether or not it is before bath hot water supply, that is, whether or not a rapid increase in hot water supply load can occur. Here, if it is determined before hot water supply in the bath (that is, a state in which a rapid increase in hot water supply load does not occur), whether or not the detected value of the first temperature detection means TH1 is 60 ° C. or higher in step S8. (I.e., whether hot hot water is currently full) or not, if it is 60 ° C. or higher (that is, if it is full), no further hot water storage is required, so heat pump hot water supply The operation of the device Z is stopped (step S11). On the other hand, when the detected value of the first temperature detecting means TH1 is 60 ° C. or less, the operation of the heat pump hot water supply device Z is started to increase the amount of stored hot water (step S9). Since the load is small, the operation frequency of the compressor 11 is set to a high efficiency point (that is, the point A in FIG. 4) to perform high efficiency operation.

  If it is determined in step S4 that the hot water has been supplied after bath supply (that is, if the amount of remaining hot water is considered to have decreased due to bath hot water supply), first, in step S5, the detected value of the second temperature detection means TH2 is 60. It is determined whether or not the temperature is equal to or higher than ° C. (that is, whether or not the hot water is currently equal to or higher than the minimum amount of hot water that does not cause hot water shortage). If the detected value of the second temperature detecting means TH2 is 60 ° C. or higher (that is, there is a hot water storage amount that is more than the minimum hot water storage amount, and no hot water supply load greater than this occurs after hot water supply to the bath) If it is determined that it is not necessary to cook again, the operation of the heat pump water heater Z is stopped (step S11).

  On the other hand, when the detected value of the second temperature detecting means TH2 is 60 ° C. or less, the amount of stored hot water is reduced to a minimum amount of hot water or less, and therefore it is determined that additional cooking is necessary from the viewpoint of preventing hot water from running out. In that case, first, in step S6, it is determined whether or not the current outside air temperature is 20 ° C. or lower (that is, whether the heat pump heating means 1 is in an environment where the cooking capacity is high or low). Here, when it is determined that the outside air temperature is 20 ° C. or higher, it is in an environment where the cooking capacity of the heat pump heating means 1 is high, and no additional cooking with a higher cooking capacity is required. Therefore, in this case, the heat pump hot water supply device Z is additionally cooked at a high efficiency point to recover the amount of stored hot water (step S7). On the other hand, when the outside air temperature is 20 ° C. or less, it is an environment where the cooking capacity of the heat pump heating means 1 is low and the prevention of hot water outflow is most important. The operating frequency of the machine 11 is increased, and the heat pump hot water supply device Z is additionally cooked and operated at a high capacity point so as to recover the hot water storage amount early (step S10).

  As described above, since the operation control of the heat pump hot water supply device Z is performed based on both the outside air temperature and the time period of one day, it is possible to achieve both the prevention of the heat pump hot water supply device Z from running out and the energy saving operation. Is.

  In the above embodiment, an example of a system in which water is directly introduced into the water heat exchanger 12 of the heat pump heating means 1 and hot water obtained by the heat exchange is stored in the hot water storage tank 21 will be described as an example. However, the present invention is not limited to such a method, for example, a method of obtaining hot water by circulating water between the hot water storage tank 21 and the water heat exchanger 12 of the heat pump heating means 1, Of course, various systems such as a system in which a heat exchanger for heating provided on the heat pump heating means 1 side is disposed in the hot water storage tank 21 to heat the water in the hot water storage tank 21 can be adopted.

It is a system diagram of a heat pump hot water supply apparatus according to the present invention. It is an operation control flowchart of the heat pump hot-water supply apparatus shown in FIG. It is a control area map in operation control of a heat pump hot-water supply apparatus. It is an "operation frequency-operation efficiency" diagram in a heat pump hot-water supply apparatus. It is a hot water supply load with respect to the external temperature in a heat pump hot-water supply apparatus, and the change state explanatory drawing of cooking capacity. It is a change state explanatory view of the amount of hot water for the outside air temperature in a heat pump hot-water supply apparatus. It is change state explanatory drawing of the hot water supply load of the day in winter. It is change state explanatory drawing of the heat pump heating amount of the day in winter. It is change state explanatory drawing of the amount of remaining hot water of the day in winter. It is change state explanatory drawing of the hot water supply load of the day in summer. It is change state explanatory drawing of the heat pump heating amount of the day in summer. It is change state explanatory drawing of the amount of remaining hot water of the day in summer.

Explanation of symbols

  1 is a heat pump heating means, 2 is a hot water storage / hot water supply means, 3 is an outside air temperature detection means, 4 is a time measuring means, 5 is a controller, 11 is a compressor, 12 is a water heat exchanger, 13 is a pressure reducing means, and 14 is air A heat exchanger, 21 is a hot water storage tank, 22 is a water pump, 31 to 35 are pipes, TH1 is first temperature detecting means, and TH2 is a heat pump hot water supply device.

Claims (6)

A heat pump hot water supply apparatus configured by connecting a heat pump heating means (1) including a compressor (11) whose capacity is variable based on an operation frequency and a hot water storage tank (21) by piping,
Based on both the outside air temperature detecting means (3) for detecting the outside air temperature, the time measuring means (4) for detecting the time, and the outside air temperature detected by the outside air temperature detecting means (3) and the time zone of the day. A heat pump hot-water supply apparatus comprising a control means (5) for changing an operating frequency of the compressor (11). In claim 1,
The control means (5) operates the compressor (11) at a first frequency at which high efficiency can be obtained in a night time zone. In claim 1,
The said control means (5) changes and sets the operating frequency of the said compressor (11) according to external temperature in a daytime time slot | zone, The heat pump hot-water supply apparatus characterized by the above-mentioned. In claim 3,
The compressor (11) is operated at a first frequency at which high efficiency is obtained when the outside air temperature is high, and at a second frequency higher than the first frequency when the outside air temperature is low. Heat pump water heater. In claim 1,
The heat pump hot water supply apparatus, wherein the refrigerant circulating through the heat pump heating means (1) is a CO2 refrigerant. In claim 1,
The heat pump hot-water supply apparatus, wherein the compressor (11) is a swing type compressor.

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