JP2011153792A - Defrosting operation method for heat pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To respond to decline in efficiency of defrosting operation caused by blowing-in of wind during the defrosting operation. <P>SOLUTION: During the defrosting operation started by a defrosting operation control part 24 when a refrigerant temperature sensed by a refrigerant inflow temperature sensor 20 becomes a set temperature or lower, if an air blowing fan control means 24a detects that 400 rpm or more of rotational frequency of an air blowing fan 18 is continued for one minute or longer or if an average refrigerant temperature increase calculation means 24b determines that an average temperature increase per minute of refrigerant temperatures sensed by a refrigerant discharge temperature sensor 19 and the refrigerant inflow temperature sensor 20 is less than 1°C, it is determined that wind is blown in to inside of an air heat exchanger 16, and the set temperature for starting next defrosting operation is increased by a predetermined value by a defrosting operation start temperature raising means 24c. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a defrosting operation method for the purpose of removing frost, in particular, for a heat pump apparatus including a refrigerant circuit.

  Conventionally, in this type, in order to prevent the air heat exchanger constituting the refrigerant circuit from frosting due to a decrease in the outside air temperature and the heat exchange efficiency from decreasing, a refrigerant that has been made high temperature and high pressure by a compressor is used. In the defrosting operation that melts frost by flowing into the air heat exchanger, it is judged that there is frost from the outside air temperature or the refrigerant temperature in the air heat exchanger, and the hot water in the hot water storage tank is boiled to a predetermined temperature. The defrosting operation is surely judged and started by starting the defrosting operation under the first defrosting start condition if the heating operation is in progress and after the second defrosting starting condition if the heating operation is over. There was something that performed frost operation.

JP 2007-278551 A

  However, in this conventional system, when the wind blows into the air heat exchanger during the defrosting operation, the amount of heat of the high-temperature refrigerant that has flowed into the air heat exchanger is radiated to the atmosphere, so that the refrigerant temperature decreases, and the defrosting is performed. Decreased performance increases the time required for defrosting operation, and there may be a case where unmelted frost is generated, and heat is exchanged with the outside air in the air heat exchanger as the unmelted frost grows. There was a problem that the exchange amount decreased.

  In order to solve the above-mentioned problems, in claim 1 of the present invention, a refrigerant circuit in which a compressor, a radiator, an expansion valve, and an air heat exchanger as an evaporator are sequentially connected, and the air heat exchanger flows. A heat pump comprising a refrigerant temperature detector that detects the temperature of the refrigerant, a blower fan that blows outside air into the air heat exchanger, and a defrosting operation control unit that starts a defrosting operation when the refrigerant temperature detector falls below a set temperature. In the defrosting operation method of the apparatus, when the defrosting operation control unit detects that air is blowing into the air heat exchanger during the defrosting operation, the set temperature for starting the defrosting operation is increased by a predetermined value. It is something to be made.

  According to a second aspect of the present invention, the defrosting operation control unit detects that the blower fan continues to rotate for a predetermined time during the defrosting operation, thereby blowing air into the air heat exchanger. It is something to detect.

  According to a third aspect of the present invention, the defrosting operation control unit detects the blowing of air into the air heat exchanger by calculating an average rise temperature in a predetermined time of the refrigerant temperature detected by the refrigerant temperature detector. To do.

  According to the present invention, when the blowing of air into the air heat exchanger during the defrosting operation is detected, the set temperature for starting the defrosting operation is increased by a predetermined value and the defrosting operation is started earlier than usual. Therefore, by performing the defrosting operation in a state where the amount of frost formation is small, the frosting of the air heat exchanger can be surely melted and the time for the defrosting operation can be further shortened. Defrosting operation can be performed.

  In addition, it is possible to determine the occurrence of wind blowing into the air heat exchanger with extremely simple means such as the rotation of the blower fan for a predetermined time and the average temperature rise of the refrigerant heat exchanger for a predetermined time. It is.

The schematic block diagram of the heat pump apparatus showing one Embodiment of this invention The flowchart which showed operation of the heat pump unit of one embodiment of this invention The flowchart which showed the detail of the defrost operation shown in FIG. The flowchart which showed the detail of the defrost operation different from FIG.

Next, an embodiment in which the present invention is applied to a heat pump water heater will be described with reference to FIG.
1 is a hot water storage tank for storing hot water heated by the heat pump unit 2, 3 is a water tap for supplying city water in the water supply pipe 4 to the hot water storage tank 1 at a constant pressure, and 5 is a kitchen or washbasin It is a hot water tap provided at a place.

  6 is a mixing valve for adjusting the valve opening degree so that the hot water supply set temperature is reached by connecting the hot water pipe 7 into which hot water flows into the upper part of the hot water storage tank 1 and the feed water bypass pipe 8 branched from the feed water pipe 4. This is a hot water supply pipe that conveys hot water adjusted to the hot water supply set temperature to the hot water tap 5.

  Reference numeral 10 denotes a heat pump forward pipe that connects the lower part of the hot water storage tank 1 and the heat pump unit 2 with a pipe, 11 denotes a heat pump return pipe that connects the heat pump unit 2 and the upper part of the hot water storage tank 1 with a pipe, and 12 denotes an intermediate part of the heat pump forward pipe 10. This is a heat pump circulation pump that conveys hot water in the hot water storage tank 1 into the heat pump unit 2.

  The heat pump unit 2 includes a compressor 13 that compresses the refrigerant, a radiator 14 that exchanges heat between the high-temperature and high-pressure refrigerant and the hot water in the hot water storage tank 2, and an expansion valve 15 that serves as a decompression unit that decompresses the refrigerant after passing through the radiator. And an air heat exchanger 16 as an evaporator for evaporating the low-temperature and low-pressure refrigerant from the expansion valve 15 is configured by a heat pump cycle 17 that is connected in an annular shape by a refrigerant pipe. Reference numeral 18 denotes a blower fan for adjusting the evaporation capacity by adjusting the amount of air flowing through the air heat exchanger 16.

  A refrigerant discharge temperature detector 19 is installed between the compressor 13 and the air heat exchanger 16 to detect a refrigerant discharge temperature, and 20 is installed between the expansion valve 15 and the air heat exchanger 16 to flow in the refrigerant. It is a refrigerant inflow temperature detector which detects temperature. Reference numeral 21 denotes an outside air temperature detector that is provided on the air inlet side of the air heat exchanger 16 and detects the outside air temperature.

  A heating control unit 22 receives the output from each detector in the heat pump unit 2 and controls the operation of each device. The heating control unit 22 is based on information from the hot water storage temperature detectors 23 installed on the side of the hot water storage tank 1. The circulation pump 12 is driven, and a heating operation control means 22a for boiling hot water in the lower part of the hot water storage tank 1 by driving the blower fan 18 at a predetermined rotational speed based on information from the outside air temperature detector 21 is provided.

  24, when the outside air temperature detector 21 detects a temperature lower than the set temperature, the operation of the heat pump circulation pump 12 and the blower fan 18 is stopped, and the refrigerant heated to high temperature and high pressure by the compressor 13 is fully opened to open the expansion valve 15 and the air heat exchanger 16. It is a defrosting operation control part which controls the defrosting operation which melts the frost adhering to the air heat exchanger 16 by flowing in, and measures the time when the blower fan 18 stopped during the defrosting operation is rotated by the wind Blower fan control means 24a for performing, refrigerant discharge temperature detector 19 during the defrosting operation, average refrigerant rise temperature calculating means 24b for calculating the average rise temperature per predetermined time of the refrigerant inflow temperature detector 20, and blower fan control means 24a or defrosting operation start temperature raising means 24c for raising the set temperature for starting the defrosting operation by a predetermined value based on the result detected by the average refrigerant rise temperature calculating means 24b. It is one that is equipped.

Next, operation | movement of the heat pump unit 2 of this embodiment is demonstrated based on the flowchart of FIG.
First, based on the temperature information obtained by the hot water storage temperature detectors 23 installed on the side surface of the hot water storage tank 1, the heating control means 22 starts the boiling operation or determines by the boiling operation control means 22a (S101). . When starting the boiling operation, the blower fan 18 is driven to blow the outside air into the air heat exchanger 16 (S102), and the compressor 13 is operated (S103). On the other hand, when the boiling operation is not performed, the determination in S101 is repeated.

  Next, the heating control unit 22 determines whether the refrigerant temperature detected by the refrigerant inflow temperature detector 20 is equal to or lower than a set temperature (for example, −15 ° C.) (S104). Defrosting operation is started on the assumption that frost is frosted on S16 (S105), and if the temperature exceeds the set temperature, frost is not formed and the process proceeds to S106.

  Then, when the defrosting operation of S105 is completed, the heating control unit 22 restarts the operation of the blower fan 18 stopped during the defrosting operation (S106). Thereafter, the heating control unit 22 determines whether to end or continue the boiling operation based on the information of the boiling operation control means 22a (S107). When ending the boiling operation, the operation of the compressor 13 is stopped (S108), the operation of the blower fan 18 is stopped (S109), and the operation of the heat pump unit 3 is ended. On the other hand, when continuing a boiling operation, it returns to S104 again and it is judged whether the temperature detected with the refrigerant | coolant inflow temperature detector 20 is below setting temperature.

Next, the details of the defrosting operation in S105 described above will be described with reference to FIG.
First, when the defrosting operation is started, the blower fan 18 is stopped by the defrosting operation control unit 24 so that the outside air is not blown into the air heat exchanger 16 (S201). Next, it is determined whether or not the blower fan 18 is rotated at 400 rpm or more by the wind during the defrosting operation by the blower fan control means 24a (S202). If the rotation speed is 400 rpm or more, the blower fan control means 24a is rotated by the blower fan control means 24a. The duration of the state is calculated (S203), and if the number of revolutions is less than 400 rpm, the value detected by the refrigerant discharge temperature detector 19 is viewed to proceed to the next determination (S204).

  Next, it is determined whether or not the time during which the blower fan 18 calculated at S203 has been rotated at 400 rpm or more has continued for 1 minute or longer (S205), and if it is determined that it has continued for 1 minute or longer, the refrigerant discharge temperature detector 19 The refrigerant discharge temperature detected at step S206 is detected (S206). If it has not continued for 1 minute or longer, it is again determined at step S202 whether the rotational speed of the blower fan 18 during the defrosting operation is 400 rpm or higher.

  Next, it is determined whether the refrigerant discharge temperature detected in S206 is 15 ° C. or higher (S207). If it is 15 ° C. or higher, the set temperature at which the defrosting start temperature raising means 24c starts the next defrosting operation is set. The setting is changed so as to increase by a predetermined value (for example, 2 ° C.) (S208), and if the refrigerant discharge temperature is less than 15 ° C., the duration time of the defrost operation exceeds the set limit time or the defrost operation control The unit 24 determines (S209) and if the limit time is exceeded, the defrosting operation is terminated and the process proceeds to the determination of S208. If the time is less than the limit time, is the refrigerant discharge temperature 15 ° C or higher again in S207? to decide.

  On the other hand, if the refrigerant discharge temperature is detected in S204, it is determined whether the refrigerant discharge temperature is 15 ° C. or higher as in S207 (S210). If the temperature is 15 ° C. or higher, the defrosting operation is terminated. Similarly to S209, it is determined whether the duration of the defrosting operation exceeds the limit time (S211). If the limit time is exceeded, the defrosting operation is terminated. It is determined whether the rotational speed of 18 is 400 rpm or more.

Next, what is performed in the embodiment different from FIG. 3 in the above-described defrosting operation in S104 will be described with reference to FIG.
First, when the defrosting operation is started, the defrosting operation control unit 24 stops the blower fan 18 (S303), performs the defrosting operation, and the refrigerant discharge temperature detected by the refrigerant discharge temperature detector 19 is 15 ° C. If it is above (S302), if it is 15 degreeC or more, a defrost operation will be complete | finished, and if it is less than 15 degreeC, it will be judged whether the continuation time of a defrost operation has exceeded the limit time (S303), If the time limit is exceeded, the process proceeds to S304, and if it is less than the time limit, the refrigerant discharge temperature is detected again in S302.

  Next, the average temperature in the air heat exchanger 16 that has risen per predetermined time (for example, 1 minute) during the defrosting operation by the average refrigerant rise temperature calculating means 24b is used as the refrigerant discharge temperature detector 19 and the refrigerant inflow temperature detector 20. (S304). Accordingly, it is determined whether the calculated average refrigerant rising temperature is less than 1 ° C. (S305). If the average rising temperature is less than 1 ° C., the defrosting operation start temperature increasing means 24c sets a set temperature at which the next defrosting operation is started. A predetermined value (for example, 2 ° C.) is raised (S306), and if the average rise temperature is 1 ° C. or higher, the defrosting operation is terminated as usual.

  As described above, the frost formation amount of the air heat exchanger 16 is detected by increasing the set temperature at which the defrosting operation is started by detecting the blowing of outside air into the air heat exchanger 16 during the defrosting operation. Since the defrosting operation is started in a state where there is little frost, it is possible to prevent frost from remaining unmelted, and the efficiency of the defrosting operation is improved by reducing the time required for the defrosting operation.

  In addition, although the said Example demonstrated the example which applied this invention to the heat pump water heater provided with the hot_water | molten_metal supply function, this invention is applicable not only to this but the heat pump apparatus provided with the heating function using hot-water supply hot water. It is.

  Moreover, although the said Example demonstrated the example which applied this invention to the heat pump water heater which boils the hot water in the hot water storage tank 1 with the heat pump unit 2, this invention is not limited to this, For example, air conditioners, such as an air conditioner It can also be applied to other outdoor units.

DESCRIPTION OF SYMBOLS 13 Compressor 14 Radiator 15 Expansion valve 16 Air heat exchanger 18 Blower fan 19 Refrigerant discharge temperature detector 20 Refrigerant inflow temperature detector 24 Defrost operation control part

Claims (3)

  A refrigerant circuit in which a compressor, a radiator, an expansion valve, and an air heat exchanger as an evaporator are sequentially connected, a refrigerant temperature detector that detects the temperature of the refrigerant flowing in the air heat exchanger, and the air heat exchanger. In the defrosting operation method of the heat pump device, the defrosting operation control unit includes a blower fan for blowing outside air and a defrosting operation control unit that starts a defrosting operation when the refrigerant temperature detector is equal to or lower than a set temperature. When detecting that air is blowing into the air heat exchanger during the defrosting operation, the set temperature for starting the defrosting operation is increased by a predetermined value.   The defrosting operation control unit detects blowing of air into the air heat exchanger by detecting that the blower fan is continuously rotating for a predetermined time during the defrosting operation. The defrosting operation method of the heat pump device according to claim 1.   The defrosting operation control unit detects the blowing of air into the air heat exchanger by calculating an average rise temperature in a predetermined time of the refrigerant temperature detected by the refrigerant temperature detector. Item 2. A defrosting operation method for a heat pump device according to Item 1.

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