JP2010071546A - Heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type water heater with improved energy saving performance and very high usability. <P>SOLUTION: The heat pump type water heater includes: a heat pump cycle composed by annularly connecting a compressor 4, a refrigerant-water heat exchanger 5, a pressure reducing device 6, and an evaporator 7; and a heating circuit composed by annularly connecting a hot water storage tank 3, a circulation pump 10 conveying low temperature water in a lower part of the hot water storage tank 3 to the refrigerant-water heat exchanger 5, and the refrigerant-water heat exchanger 5. By changing heating capacity of the heat pump cycle in response to a residual hot water amount in the hot water storage tank 3, a target heating temperature of hot water produced by the refrigerant-water heat exchanger 5, and a supply temperature of water supplied to the hot water storage tank 3, and determining an overnight heating start time, heating operation with favorable operation efficiency is made possible, and the energy saving performance can be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat pump type hot water supply apparatus using a heat pump cycle.

  Regarding the operation of the heat pump unit of the conventional heat pump type hot water supply apparatus, there has been one that varies the heating capacity of the heat pump cycle in accordance with the amount of remaining hot water in the hot water storage tank of the tank unit. In the conventional heat pump unit, if the amount of remaining hot water in the hot water storage tank is more than a certain predetermined amount, the heating capacity is suppressed to suppress operation noise, and if the remaining hot water amount in the hot water storage tank is less than a certain predetermined amount, the heating capacity is reduced. (See, for example, Patent Document 1).

In general, a heat pump type hot water supply apparatus uses hot midnight power with a low electricity charge to boil hot water in a hot water storage tank to a set temperature. For this reason, peak shift control is performed so that boiling is completed during a time period in which midnight power can be used (from 23:00 to 7:00 the next day) (see, for example, Patent Document 2). With peak shift control, the amount of heat required to boil the entire amount in the hot water storage tank is determined, the time required to cover the required amount of heat is determined from the heating capacity of the heat pump unit, and the boiling operation is completed at 7:00 the next day after the end of midnight. As described above, the boiling operation start time in the midnight time zone is obtained, and as a result, the heating is not overheated quickly, so that the heat dissipation loss after the boiling can be suppressed.
JP 2003-90606 A JP 2007-85651 A

  However, in the heating operation of the conventional heat pump type hot water supply device, the boiling operation time is obtained by the peak shift control from the constant heating capacity, so the boiling operation is completed at midnight, but the efficiency of the boiling operation is There was a problem that was not considered.

  This invention solves the said conventional subject, and it aims at providing the heat pump type hot water supply apparatus with the very high usability which improved energy-saving property.

  In order to solve the conventional problems, a heat pump type hot water supply apparatus of the present invention includes a compressor that compresses a refrigerant, a refrigerant water heat exchanger that exchanges heat between the refrigerant and water, a decompression device that depressurizes the refrigerant, and a refrigerant. A heat pump cycle configured by sequentially connecting an evaporator that exchanges heat with the atmosphere in an annular manner through a refrigerant pipe, a hot water storage tank for storing hot water, and low-temperature water in the lower part of the hot water storage tank to the refrigerant water heat exchanger A circulating pump, and a boiling circuit configured by sequentially connecting the refrigerant water heat exchanger in an annular manner by a hot water supply pipe, and the amount of hot water in the hot water storage tank and the amount of hot water generated by the refrigerant water heat exchanger By changing the heating capacity of the heat pump cycle according to the target boiling temperature and the feed water temperature of the water supplied to the hot water storage tank, and determining the night boiling start time, It enables up operation, it is possible to improve energy saving.

  INDUSTRIAL APPLICABILITY The present invention can provide a heat pump type hot water supply device with improved energy saving and high usability.

  A heat pump hot water supply apparatus according to a first aspect of the present invention includes a compressor that compresses a refrigerant, a refrigerant water heat exchanger that exchanges heat between the refrigerant and water, a decompression device that depressurizes the refrigerant, and an evaporation that exchanges heat between the refrigerant and the atmosphere. A heat pump cycle configured by sequentially connecting the chambers in an annular manner by refrigerant piping, a hot water storage tank for storing hot water, a circulation pump for transporting low temperature water at the lower part of the hot water storage tank to the refrigerant water heat exchanger, and the coolant water heat A boiling circuit configured by sequentially connecting the exchangers in an annular manner by hot water supply piping, the amount of remaining hot water in the hot water storage tank, the target boiling temperature of hot water generated by the refrigerant water heat exchanger, and the hot water storage By changing the heating capacity of the heat pump cycle according to the water supply temperature of the water supplied to the tank and determining the boiling start time at night, it is possible to perform a boiling operation with good operating efficiency, and to save energy. It is possible to improve the resistance.

  The heat pump type hot water supply apparatus according to the second invention, particularly in the first invention, can be surely heated in the midnight time zone by determining the heating capacity of the heat pump cycle so that the boiling is completed in the midnight time zone. Because it is set to a heating capacity that can be used, inexpensive late-night power can be used.

  In the heat pump type hot water supply apparatus of the third invention, particularly in the first or second invention, since the compressor has a configuration without an accumulator, the heat pump type hot water supply apparatus main body can be reduced in size and weight.

  The heat pump type hot water supply apparatus according to the fourth aspect of the present invention is the first to third aspects of the invention. In particular, when the refrigerant pressure on the high-pressure side becomes equal to or higher than the critical pressure, water is deprived of heat by the refrigerant water heat exchanger and the temperature decreases. Even if it does not condense, it becomes easier to form a temperature difference between the refrigerant and water in the entire flow path of the refrigerant water heat exchanger, and hot water can be obtained and heat exchange efficiency can be increased. it can.

  In the heat pump type hot water supply apparatus of the fifth invention, in particular, in the first to fourth inventions, carbon dioxide is used as the refrigerant, so that the product cost can be suppressed and the reliability can be improved. Furthermore, since carbon dioxide has a zero ozone depletion coefficient and a global warming coefficient of about 1/700 that of the alternative refrigerant HFC-407C, it can provide a product that is friendly to the global environment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a heat pump hot water supply apparatus according to Embodiment 1 of the present invention. In FIG. 1, the heat pump hot water supply apparatus of the present invention includes a heat pump unit 1 as a heating source and a tank unit 2 having a hot water storage tank 3 for storing hot water. First, the heat pump unit 1 will be described. In addition, the arrow shown in a figure shows the direction through which a refrigerant | coolant or water flows, respectively.

  The heat pump unit 1 includes a compressor 4 that does not have an accumulator that compresses the refrigerant into a high-temperature and high-pressure refrigerant, a refrigerant water heat exchanger 5 that heat-exchanges the refrigerant and water to generate high-temperature water, and a decompressor 6 that decompresses the refrigerant. In addition, an evaporator 7 in which the atmosphere and the refrigerant exchange heat and the refrigerant absorbs heat from the atmosphere is sequentially connected to the refrigerant pipe 8 in a ring shape so as to have a heat pump cycle. Further, a fan 19 that promotes heat exchange between the refrigerant and air in the evaporator 7 and a fan motor 20 that drives the fan 19 are provided.

Carbon dioxide is used as the refrigerant, and the refrigerant after being compressed by the compressor 4 exceeds the supercritical pressure, and circulates in the refrigerant pipe as indicated by arrows in FIG. It should be noted that the refrigerant can be replaced with carbon dioxide instead of a fluorocarbon refrigerant such as R410A, or a hydrocarbon refrigerant such as propane, but there is no problem as a water heater. And the reliability can be improved. Furthermore, since carbon dioxide has a zero ozone depletion coefficient and a global warming coefficient of about 1/700 that of the alternative refrigerant HFC-407C, it can provide a product that is friendly to the global environment.

  Next, the tank unit 2 will be described. The tank unit 2 has a hot water storage tank 3 for storing hot water, and a circulation pump 10 for conveying low temperature water from the bottom of the hot water storage tank 3 to the refrigerant water heat exchanger 5 in the heat pump unit 1 is provided. And the bottom part of the hot water storage tank 3, the circulation pump 10, and the refrigerant | coolant water heat exchanger 5 are connected cyclically | annularly with hot water supply piping, the boiling circuit is formed, and the circulation pump 10 is driven, From the bottom part of the hot water storage tank 3, Low temperature water is conveyed to the refrigerant water heat exchanger 5. And the hot water produced | generated with the refrigerant | coolant water heat exchanger 5 is sent to the upper part of the hot water storage tank 3 through the upper hot water supply piping 18. FIG.

  A water supply pipe 15 for supplying water from a water supply source is connected to the water supply port 14 provided at the lower part of the hot water storage tank 3, and the hot water outlet 16 provided at the upper part of the hot water storage tank 3 is connected to the hot water supply terminal at a high temperature. A hot water supply pipe 17 for supplying water is connected. And the water supply port 14 is in a state where the water pressure from the water supply source is constantly applied, and water is supplied from the water supply port 14 as hot water is discharged from the hot water supply pipe 17.

  In addition, a thermistor 33 that is a plurality of remaining hot water detection means is provided on the side wall of the hot water storage tank 3 and detects the amount of hot water remaining by detecting the hot water temperature with the thermistor 33. be able to. Furthermore, the thermistor 31 which is an inlet temperature detection means for detecting the incoming water temperature at the water side inlet of the refrigerant water heat exchanger 5 and the hot water temperature at the water side outlet of the refrigerant water heat exchanger 5 are detected. A thermistor 32 serving as a tapping temperature detecting means is provided.

  Furthermore, it has the heat pump unit control apparatus 9 for controlling the apparatus arrange | positioned in the heat pump unit 1, and is instruct | indicating operation | movement instructions, such as at the time of a boiling operation, to each apparatus. Similarly, the tank unit 2 has a tank unit control device (not shown) for controlling devices.

  About night heat-up control about the heat pump type hot-water supply apparatus comprised as mentioned above is demonstrated.

  The basic boiling of the heat pump hot water supply apparatus of the present invention is performed in the midnight time zone from 23:00 to 7:00 the next day. And a user's daily usage etc. are learned and the temperature of the hot water stored in a hot water storage tank is changed within the range of 65 degreeC-90 degreeC according to the learned amount of boiling hot water. For example, if the amount of hot water used by a daily user is small, the temperature of the hot water is lowered and heated, and if the amount of hot water used by a daily user is large, the temperature of the hot water is increased and heated. ing. As a result, wasteful boiling is reduced and a very energy-saving hot water supply apparatus can be provided.

  FIG. 2 is a flowchart at the time of boiling of the heat pump type hot water supply apparatus of the present invention. As shown in FIG. 2, first, the amount of boiling water is determined by learning the amount of daily hot water used (STEP 1). It should be noted that the boiling immediately after the installation work is configured to boil a certain amount for the first few days because there is no past use record.

When the amount of boiling water (boiling temperature) is determined, the circulating pump 10 is driven and the incoming temperature is detected by the thermistor 31 after the midnight time zone or just before the midnight time zone (STEP 2). ). Further, the remaining amount of hot water in the hot water storage tank 3 is detected by the thermistor 33 (STEP 3), and the amount of heat necessary for boiling is determined by calculation (STEP 4).

  FIG. 3 is an example of characteristics indicating heating capacity, operating efficiency, suction pressure, and discharge pressure when the opening of the decompression device 6 is constant and the operating frequency of the compressor 4 is changed. As shown in FIG. 3, although the output pressure increases slightly as the operating frequency of the compressor 4 increases, it is substantially constant, the suction pressure decreases, and the heating capacity increases. However, the driving efficiency has a peak value, and driving at the driving frequency that takes the peak value maximizes the driving efficiency.

  Next, the heating capacity and the boiling operation start time are calculated (STEP 5). First, as shown in FIG. 3, it is determined whether or not the boiling operation is completed in the midnight time zone from 23:00 to the next 7:00 when the heating operation is performed with the heating ability a at which the operation efficiency takes a peak value. As a result, if it is determined that the heating can be completed with the heating capacity a, the heating capacity is set to a, and the boiling start time is calculated so that the boiling is completed at the next 7 o'clock. When the calculated boiling start time is reached, each device is controlled so that the heating capacity is a, and the boiling operation is performed.

  When it is judged that the boiling operation cannot be completed in the midnight time zone from 23:00 to 7:00 when the boiling operation is performed with the heating capacity a, the heating capacity is increased from the point where the operation efficiency reaches the peak value. The heating capacity b is set so that the boiling operation can be completed. And a heating capability is set to b and a boiling operation is performed. As described above, since the present invention is configured so that boiling is always completed using the power of the midnight time zone, the boiling operation can be performed using the inexpensive midnight power, which is extremely economical. ing.

  The method for determining the value of the heating capacity b is only required to be set to the heating capacity at which the boiling operation is completed from 23:00 to 7:00, and the heating capacity obtained by adding a predetermined value to the heating capacity a is defined as the heating capacity b. Note that the predetermined value is not uniquely determined, but may be a predetermined value according to each device. In the present embodiment, a predetermined value is added to the heating capability a a plurality of times until the heating capability is reached so that boiling can be completed in the midnight time zone, thereby calculating the heating capability b.

  As described above, by performing the boiling operation with the maximum operation efficiency, it is possible to provide a heat pump type hot water supply apparatus that is extremely high in energy saving and excellent in economy.

  As described above, the heat pump hot water supply apparatus according to the present invention includes an integrated heat pump hot water supply apparatus in which the heat pump cycle and the hot water supply cycle are integrally configured, a separate heat pump hot water supply apparatus configured separately, and refrigerant water heat exchange. The present invention can be applied to various heat pump type hot water supply devices such as a direct hot water heat pump type hot water supply device that can discharge hot water heated by a vessel as it is.

The block diagram of the heat pump type hot-water supply apparatus in Embodiment 1 of this invention Flow chart of boiling control in the same embodiment Characteristic diagram of compressor in the same embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat pump unit 2 Tank unit 3 Hot water storage tank 4 Compressor 5 Refrigerant water heat exchanger 6 Pressure reducing device 7 Evaporator 8 Refrigerant piping 9 Heat pump unit control device 10 Circulation pump 14 Water supply port 15 Water supply piping 16 Hot water outlet 17 Hot water supply piping

Claims (5)

A compressor that compresses the refrigerant, a refrigerant water heat exchanger that exchanges heat between the refrigerant and water, a decompression device that depressurizes the refrigerant, and an evaporator that exchanges heat between the refrigerant and the atmosphere are sequentially connected in an annular fashion by refrigerant piping. A heat pump cycle configured, a hot water storage tank for storing hot water, a circulation pump for transporting low temperature water at the lower part of the hot water storage tank to the refrigerant water heat exchanger, and the refrigerant water heat exchanger are sequentially connected in an annular shape by hot water supply piping. A boiling circuit configured as described above, and a remaining amount of hot water in the hot water storage tank, a target boiling temperature of hot water generated by the refrigerant water heat exchanger, and a water supply temperature of water supplied to the hot water storage tank Accordingly, the heating capacity of the heat pump cycle is changed, and then the boiling start time in the midnight time zone is determined. 2. The heat pump hot water supply apparatus according to claim 1, wherein the heating capacity of the heat pump cycle is determined so that boiling is completed in the late-night time zone. The heat pump hot water supply apparatus according to claim 1 or 2, wherein the compressor has a configuration without an accumulator. The heat pump type hot water supply apparatus according to any one of claims 1 to 3, wherein the refrigerant pressure on the high pressure side is equal to or higher than a critical pressure. The heat pump type hot water supply apparatus according to any one of claims 1 to 4, wherein carbon dioxide is used as a refrigerant.

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