JP4089745B2 - Heat pump water heater - Google Patents

Description

  The present invention has a heat pump circuit in which a compressor, a hot water heat exchanger, an expansion valve, and an evaporator are connected by piping, and a circulation circuit in which a hot water storage tank, a fluid circulation pump, and a hot water heat exchanger are connected by piping. The present invention relates to detection of erroneous connection of a circulation circuit of a heat pump water heater.

  Heat pump hot water supply that can be detected as an incorrect connection when the incoming water supply line supplied to the hot water supply heat exchanger and the outgoing hot water supply line returned from the hot water supply heat exchanger to the hot water storage tank are connected in reverse. An apparatus has been proposed (see, for example, Patent Document 1).

In Patent Document 1, when the incoming water temperature is high by comparing the incoming water temperature of the incoming water pipeline supplied to the hot water supply heat exchanger with the outgoing hot water temperature of the outgoing hot water pipeline returned from the hot water supply heat exchanger to the hot water storage tank. It is determined that the incoming and outgoing piping lines are misconnected.
JP 2003-222406 A

  However, the conventional heat pump hot-water supply apparatus determines completion of boiling of the hot water storage tank based on the incoming water temperature, and ends the boiling operation when the incoming water temperature exceeds a predetermined temperature.

  However, if the incoming water pipe line and the outgoing hot water pipe line are erroneously connected in reverse, the incoming water temperature rises even when the hot water storage tank is not boiling.

  As described above, in Patent Document 1, since the incoming water temperature and the hot water temperature are compared to determine an erroneous connection between the incoming water pipe and the outgoing hot water pipe, an error occurs until the heat pump water heater determines that the boiling is completed. A connection must be detected.

  However, when erroneous connection detection is performed in a short time, the regular connection may be erroneously determined as an erroneous connection. For example, as a common condition at the start of boiling operation in winter, the hot water boiled on the previous day remains in the hot water storage tank, and the tank temperature is 45 ° C. When the temperature is cooled to 10 ° C., when the boiling operation is started, 45 ° C. water is supplied from the hot water storage tank to the hot water supply heat exchanger, so the incoming water temperature is earlier than the outgoing hot water temperature. It will rise. In this case, if the erroneous connection determination time is short, it is erroneously determined as an erroneous connection.

  It is an object of the present invention to provide a heat pump hot water supply apparatus that can reliably determine an erroneous connection without erroneously determining that a hot water storage tank has been boiled up and not erroneously connected to an incoming and outgoing hot water pipes. .

In order to solve the conventional problems, a heat pump hot water supply apparatus of the present invention includes a heat pump circuit in which a compressor, a heat exchanger for hot water supply, an expansion valve, and an evaporator are connected by piping, a hot water storage tank, a fluid circulation pump, A circulation circuit in which a hot water heat exchanger is connected by piping, the circulation circuit heat-exchanged by the hot water supply heat exchanger, and a water inlet piping for supplying low temperature water from the hot water storage tank to the hot water heat exchanger. The hot water supply pipe returning the hot water to the hot water storage tank, the incoming water temperature detecting means for detecting the incoming water temperature supplied to the hot water supply heat exchanger, and the hot water temperature after heat exchange with the hot water supply heat exchanger. A hot water temperature detecting means for detecting, and a tank temperature detecting means for detecting a tank temperature of the hot water storage tank, the state where the incoming water temperature is higher than the outgoing hot water temperature by a predetermined temperature or more continues for a predetermined time, and Water temperature If a predetermined temperature higher than the serial tank temperature, characterized in that it is determined that the connection state between the entering water piping passage the hot water distribution line is erroneous.

  The heat pump hot-water supply apparatus of the present invention can reliably determine that there is an incorrect connection without erroneously determining that the hot water storage tank has been boiled up incorrectly.

  The first invention includes an incoming water temperature detecting means for detecting an incoming water temperature supplied to a hot water supply heat exchanger, an outgoing hot water temperature detecting means for detecting an outgoing hot water temperature after being subjected to heat exchange by the hot water supply heat exchanger, and hot water storage. A tank temperature detecting means for detecting the tank temperature of the tank has been provided, the state where the incoming water temperature is higher than a predetermined temperature compared to the outgoing hot water temperature continues for a predetermined time or longer, and the incoming water temperature is higher than the predetermined temperature compared to the tank temperature. In this case, it is possible to shorten the determination time of the incorrect connection by judging that the incoming pipe line and the outgoing hot water pipe line are in an incorrect connection state, without erroneously determining that the normal connection is erroneously connected. Therefore, it is possible to more reliably determine the erroneous connection of the hot water discharge piping without erroneously determining that the boiling of the hot water storage tank is completed. Furthermore, the erroneous connection determination condition can be simplified.

  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)
1 is a circuit configuration diagram of a heat pump water heater in Embodiment 1 of the present invention. First, the heat pump circuit of the heat pump water heater according to the first embodiment will be described.

  The heat pump circuit 10 is configured by connecting a compressor 11, a hot water supply heat exchanger 12, a main expansion valve 13A, a capillary tube 13B, and an evaporator 14 in this order by piping. The heat pump circuit 10 includes a temperature sensor 10A for detecting the temperature of the compressor 11, a temperature sensor 10B for detecting the refrigerant temperature discharged from the compressor 11, a pressure sensor 10C for detecting the refrigerant pressure discharged from the compressor 11, and an evaporator. 14 is provided with a temperature sensor 10D for detecting intake air. Here, the temperature sensor 10 </ b> A detects cold start, and the pressure sensor 10 </ b> C detects abnormality of the compressor 11 or the heat pump circuit 10.

  Next, a hot water storage circuit of the heat pump water heater according to the first embodiment will be described.

  A bottom pipe 21 of the hot water storage tank 20 is connected to a water supply pipe 32 such as a water pipe via a pressure reducing valve 31. Further, the bottom pipe 22 of the hot water storage tank 20 is connected to the water inlet side connecting pipe 25 via the circulation pump 23, and the water inlet side connecting pipe 25 is connected to the water pipe 12A of the hot water supply heat exchanger 12 via the inlet side pipe 12B. Connected to the inflow side. The upper circulation pipe 24 of the hot water storage tank 20 is connected to the hot water side connection pipe 26, and the hot water side connection pipe 26 is connected to the outflow side of the water pipe 12A via the outflow side pipe 12C.

  The hot water storage tank 20 according to the present embodiment is a stacked hot water storage tank, and is configured so that stirring in the tank is prevented and high temperature water is accumulated at the top and low temperature water is accumulated at the bottom.

On the other hand, the upper hot water supply pipe 33 of the hot water storage tank 20 is connected to the mixing valve 34. Further, a water discharge pipe 35 branched from the bottom pipe 21 of the hot water storage tank 20 is connected to the mixing valve 34. The hot water supply circuit on the outflow side of the mixing valve 34 is connected to a hot water supply faucet 36 such as a kitchen or a washroom. This hot water supply circuit is provided with a flow rate sensor 30A for detecting the amount of hot water supply and a temperature sensor 30B for detecting the temperature of hot water supply.

  The hot water storage tank 20 is provided with a plurality of temperature sensors (tank temperature detection means) 20A, 20B, and 20C for detecting the amount of hot water in the hot water storage tank 20. The inflow side pipe 12 </ b> B is provided with a temperature sensor (incoming water temperature detecting means) 20 </ b> D that detects the incoming water temperature derived from the bottom pipe 22 </ b> A of the hot water storage tank 20. In addition, the outflow side pipe 12C is provided with a temperature sensor (hot water temperature detecting means) 20E for detecting the temperature of the hot water derived from the water pipe 12A.

  Hereinafter, the hot water storage operation of the heat pump hot water supply apparatus according to the first embodiment will be described.

  When the time reaches a predetermined time, or when it is detected by the temperature sensors (tank temperature detecting means) 20A, 20B, 20C in the hot water storage tank 20 that the amount of hot water in the hot water storage tank 20 has become a predetermined amount or less, the heat pump circuit 10 is operated to start the hot water storage operation.

  In the heat pump circuit 10, the refrigerant compressed by the compressor 11 dissipates heat in the hot water supply heat exchanger 12, is depressurized by the main expansion valve 13A and the capillary tube 13B, then absorbs heat in the evaporator 14, and in a gas state. It is sucked into the compressor 11.

  On the other hand, by the operation of the circulation pump 23, the water in the hot water storage tank 20 is led to the water pipe 12A through the bottom pipe 22, the water inlet side connection pipe 25, and the inflow side pipe 12B, and heated by the water pipe 12A. The hot water is returned to the hot water storage tank 20 through the outflow side pipe 12C, the hot water side connection pipe 26, and the upper circulation pipe 24.

  Next, erroneous connection detection control of the heat pump water heater according to the first embodiment will be described with reference to FIGS.

  FIG. 2 is a block diagram illustrating an erroneous connection detection control function of the heat pump hot water supply apparatus according to Embodiment 1 of the present invention.

  The erroneous connection detection means 40 includes a maximum tank temperature determination means 41, a reference tank temperature setting means 42, and a reference incoming water temperature setting means 43. The highest tank temperature determination means 41 determines the highest temperature among the temperature sensors (tank temperature detection means) 20A to 20C. The reference tank temperature setting means 42 sets a reference temperature (for example, 35 degrees) for determining whether or not the hot water storage tank is heated up on the previous day. The reference incoming water temperature setting means 43 sets a reference temperature (for example, 42 degrees) for determining that the incoming water temperature has increased to near the boiling completion temperature.

The erroneous connection detection means 40 includes a tank temperature comparison means 44, an incoming water temperature comparison means 45, an incoming and outgoing hot water temperature comparison means 46, and an erroneous connection determination means 47. The tank temperature comparison means 44 compares the maximum tank temperature determined by the maximum tank temperature determination means 41 with the reference tank temperature set by the reference tank temperature setting means 42. The incoming water temperature comparing means 45 compares the incoming water temperature detected by the temperature sensor (incoming water temperature detecting means) 20D with the reference incoming water temperature set by the reference incoming water temperature setting means 43. The incoming and outgoing hot water temperature comparing means 46 compares the hot water temperature detected by the temperature sensor (hot water temperature detecting means) 20E and the incoming water temperature detected by the temperature sensor (incoming water temperature detecting means) 20D. As a result of the comparison in the incoming / outgoing hot water temperature comparing means 46, the erroneous connection determination means 47 has a tank temperature comparison after a predetermined time (for example, 1 minute) has elapsed that the incoming water temperature is higher by a predetermined temperature difference (for example, 10K) than the outgoing hot water temperature. As a result of comparison by means 44, if the maximum tank temperature is lower than the reference tank temperature and the result of comparison by incoming water temperature comparison means 45 is that the incoming water temperature is higher than the reference incoming water temperature, it is determined that the connection is incorrect and the operation stopping means The operation is stopped by 48 and the operation is performed again. However, when the operation stop by the erroneous connection detection exceeds the specified number of times, the failure display means 49 displays that the connection is incorrect.

  FIG. 3 is a flowchart showing a flow of erroneous connection detection control of the heat pump hot water supply apparatus in Embodiment 1 of the present invention.

  At the start of operation, the temperature sensor (incoming water temperature detecting means) 20D detects the incoming water temperature, the temperature sensor (outlet water temperature detecting means) 20E detects the outgoing hot water temperature, and the temperature sensors (tank temperature detecting means) 20A to 20C detect the tank temperature of each part. To do.

  First, in step 1, it is determined whether a predetermined time (for example, 2 minutes) has elapsed after the start of operation. If it has elapsed, the continuation timer is cleared (step 2). In step 3, the incoming water temperature and the outgoing hot water temperature are detected. In step 4, the incoming water temperature and the outgoing hot water temperature are compared. If the difference is equal to or greater than the predetermined temperature difference, the continuation timer is increased (step 5). If the temperature difference is less than the predetermined temperature, the process returns to step 2. In step 6, if the continuation timer has not elapsed for a predetermined time, the process returns to step 3, and if the continuation timer has elapsed for a predetermined time or more, the incoming water temperature is compared with the reference incoming water temperature (step 7). If it is higher than the incoming water temperature, the tank temperature of each part is detected (step 8). Conversely, if the incoming water temperature is lower than the reference incoming water temperature, the process returns to step 3. In step 9, the maximum tank temperature is determined. In step 10, the maximum tank temperature is compared with the reference tank temperature. If the maximum tank temperature is equal to or higher than the reference tank temperature, the process returns to step 3; .

  As described above, in the first embodiment, it is possible to exclude the case where the hot water storage tank is heated up on the previous day, and it is possible to reliably detect an increase in the incoming water temperature. The connection determination time can be shortened, and it is possible to more reliably determine an erroneous connection without erroneously determining that the hot water storage tank has been boiled up incorrectly.

(Embodiment 2)
The circuit configuration diagram of the heat pump hot water supply apparatus in the second embodiment of the present invention is the same as the circuit configuration diagram (FIG. 1) of the heat pump hot water supply apparatus in the first embodiment, and thus the description thereof is omitted.

  The erroneous connection detection control of the heat pump hot water supply apparatus according to the second embodiment will be described with reference to FIGS.

  FIG. 4 is a block diagram showing an erroneous connection detection control function of the heat pump water heater in Embodiment 2 of the present invention.

  The erroneous connection detection means 40 includes a maximum tank temperature determination means 41, an incoming / outgoing hot water temperature comparison means 46, an erroneous connection determination means 47, and an incoming water tank temperature comparison means 50. The maximum tank temperature determination means 41, the incoming / outgoing hot water temperature comparison means 46, the operation stop means 48, and the failure display means 49 are the same as those in FIG.

  The incoming water tank temperature comparing means 50 compares the highest tank temperature determined by the highest tank temperature determining means 41 with the incoming water temperature detected by the temperature sensor (incoming water temperature detecting means) 20D. As a result of the comparison in the incoming / outgoing hot water temperature comparing means 46, the erroneous connection determination means 47 shows that the incoming water temperature is higher than the outgoing hot water temperature by a predetermined temperature difference (for example, 10K) for a predetermined time (for example, 1 minute) or longer. As a result of comparison by the comparison means 50, when the incoming water temperature is higher by a predetermined temperature difference (for example, 10K) than the maximum tank temperature, it is determined that the connection is incorrect.

  FIG. 5 is a flowchart showing a flow of erroneous connection detection control of the heat pump water heater in Embodiment 2 of the present invention.

  In this case as well, the process up to the continuation timer determination (step 6) is the same as that in FIG.

  If the continuation timer has exceeded a predetermined time in step 6, the tank temperature of each part is detected (step 8), and the maximum tank temperature is determined (step 9). The incoming water temperature is compared with the maximum tank temperature (step 12), and if the temperature difference is less than the predetermined temperature difference, the process returns to step 3;

  As described above, in the second embodiment, not only can it be determined that there is an incorrect connection, but also control can be simplified.

  As described above, the present invention is suitable for erroneous pipe detection in a heat pump hot water supply apparatus.

The circuit block diagram of the heat pump hot-water supply apparatus in Embodiment 1 of this invention The block diagram which shows the misconnection detection control function of the heat pump hot-water supply apparatus in Embodiment 1 of this invention The flowchart which shows the flow of the misconnection detection control of the heat pump hot-water supply apparatus in Embodiment 1 of this invention. The block diagram which shows the misconnection detection control function of the heat pump hot-water supply apparatus in Embodiment 2 of this invention The flowchart which shows the flow of the misconnection detection control of the heat pump hot-water supply apparatus in Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat pump circuit 11 Compressor 12 Heat exchanger for hot water supply 12A Water piping 20 Hot water storage tank 20A-C Temperature sensor (tank temperature detection means)
20D Temperature sensor (Incoming water temperature detection means)
20E Temperature sensor (Tapping temperature detection means)
22 Bottom piping 24 Top circulation piping 25 Inlet side connecting piping 26 Hot water side connecting piping

Claims (1)

A heat pump circuit in which a compressor, a hot water heat exchanger, an expansion valve, and an evaporator are connected by piping; a hot water storage tank, a fluid circulation pump; a circulation circuit in which the hot water heat exchanger is connected by piping; and the circulation circuit An inlet piping for supplying low-temperature water from the hot water storage tank to the hot water supply heat exchanger, a hot water supply piping for returning the hot water heat-exchanged by the hot water heat exchanger to the hot water storage tank, and the hot water supply heat exchange An incoming water temperature detecting means for detecting an incoming water temperature supplied to the water heater, an outgoing hot water temperature detecting means for detecting an outgoing hot water temperature after heat exchange by the hot water supply heat exchanger, and a tank for detecting a tank temperature of the hot water storage tank Temperature detection means, and when the state in which the incoming water temperature is higher than the hot water temperature by a predetermined temperature or more continues for a predetermined time and the incoming water temperature is higher than the tank temperature by a predetermined temperature, the incoming water pipe line And the hot spring The heat pump water heater, characterized in that it is determined that the road is erroneously connected.

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