JPH028230B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat pump control device for a heat pump water heater (hereinafter abbreviated as HS).

Conventional configuration and its problems In general, an HS system consists of a heat pump cycle consisting of a compressor 1, a condenser 2, a heat collector 3, an expansion valve 4, a heat storage tank 5, a circulation pump, and a condenser 2, as shown in Figure 1. It consists of a water circuit consisting of: This system collects solar radiation and atmospheric heat, so depending on the outside temperature,
The time required to raise the temperature of water in a tank of the same capacity differs depending on the season or heat collection time. Furthermore, the shorter the time required for this system to collect heat, the smaller the ratio of input to output, which increases the efficiency of the system and allows you to obtain the required amount of hot water with a lower electricity bill. For this purpose, it is known that it is best to set the center of the time period required for heat collection near 12 o'clock, when the sun's radiation contributes the most during the day. In addition, it is known that the outside temperature at the time of sunrise at dawn varies depending on the season. Therefore, the delay time from the time of sunlight was calculated based on the outside temperature at the time of sunrise, and the operation start time of compressor 1 was set. .

For the above reasons, it has become necessary to change the start time of the compressor 1 depending on the season.

FIG. 2 shows a conventional circuit diagram in which the season is determined based on the outside temperature, and the compressor is operated after a certain time delay after solar radiation according to the outside temperature, and will be described below.

In the figure, V _DC is a DC power supply, and a series circuit of a resistor 8 and a thermistor 9 is connected via a solar radiation switch 7 whose contact closes when there is solar radiation on this DC power supply V _DC. A temperature detection voltage V _T (according to the outside temperature) is obtained. Similarly, a series circuit of a resistor 10 and a resistor 11 is connected to the DC power supply V _DC to obtain a reference voltage V _B1 . Furthermore, V _B2 is similarly obtained by a series circuit of resistors 12 and 13. A voltage comparator 14 compares the temperature detection voltage V _T and the reference voltage V _B1 and outputs the result. Note that 15 is a feedback resistor, and 16 is a pull-up resistor. A voltage comparator 17 compares the temperature detection voltage V _T with a reference voltage V _B2 and outputs the result. Note that 18 is a feedback resistor, and 19 is a pull-up resistor.

The voltage comparator 14 outputs Hi when the thermistor 9 is below 20°C, and outputs Hi when the thermistor 9 is above 20°C.
The reference voltage V _B1 is set so as to be _LOW . The other voltage comparator 17 has a thermistor 9 of 10
If the temperature is below ℃, the output is Hi; if it is above 10℃,
The reference voltage V _B2 is set so that the output is _LOW . 20 is a timer IC, resistor 21,
At the time determined by capacitor 22, T ₁ ,
The outputs of T ₂ and T ₃ are set to Hi in sequence. In this case, after solar radiation SW7 is turned on, T ₁ becomes Hi after 1 hour, and T ₂
is set to become Hi after 2 hours, and T ₃ is set to become Hi after 3 hours. 23, 24, 25 are timer IC2
0 outputs T ₁ , T ₂ , and T ₃ . Diodes 26, 27, 28 are timers
This is a diode for preventing wrap-around for outputting only Hi outputs of T ₁ , T ₂ , and T ₃ of the IC 20 and applying it to the transistors 29 and 30 . 31 is a resistor for stably turning on the transistors 29 and 30. 32 is a compressor, and 33 is a pump drive relay.

In the above configuration, if the thermistor 9 senses 15°C, the output of the voltage comparator 14 will be
The signal becomes Hi, and the output of the voltage comparator 17 becomes _Low . Therefore, one hour after the solar radiation switch 7 is turned on, _T1 of the timer IC 20 becomes Hi.
The output of voltage comparator 17 connected to T _{1 is LOW}
Therefore, transistor 29, transistor 3
0 does not turn on. Then after 2 hours, the timer
When the output _T2 of IC20 becomes Hi, the voltage comparator 14
Since the output is Hi, the transistors 29 and 30 are turned on, and the relay 32 that turns on the compressor 1 and the relay 33 that turns on the pump 6 are energized, and the system is activated.

However, with this method, if the temperature of the outside air temperature sensor changes due to solar radiation or the like during the delay time, a shift in the delay time occurs. In other words, as shown in Figure 3, if the outside temperature does not change by 15 degrees Celsius after solar radiation, relays 32 and 33 will turn on after the regular delay time of 2 hours, but as shown in Figure 4, If the outside temperature at the time of solar radiation is 15°C, and 30 minutes after the sun shines, the outside temperature changes to 25°C due to the influence of solar radiation, then the delay time corresponding to the outside temperature of 15°C during the solar radiation is 2.
However, the delay time was set to 3 hours, which corresponds to 25℃, resulting in a delay in the start time of the compressor, making it impossible to operate efficiently.

Purpose of the Invention The present invention takes the above problems into consideration, and since the outside temperature immediately after solar radiation is not affected by solar radiation, it has a sufficient correlation with the seasons of spring, summer, autumn, and winter, so the temperature immediately after solar radiation is memorized. , the purpose is to obtain a delay time that accurately corresponds to the season.

Structure of the Invention In order to achieve the above object, the present invention includes a DC power supply that supplies power, a voltage comparison circuit that extracts a signal from a temperature sensor as a voltage, and compares the voltage with a reference voltage obtained by dividing the voltage by resistance. A solar radiation switch that operates by detecting solar radiation, a latch circuit that holds the signal of the voltage comparison circuit at the same time that the DC power is turned on by the operation of the solar radiation switch, and a delay timer that outputs a signal after an arbitrary set time. The load is controlled by AND outputting the signal from the latch circuit and the signal from the delay timer.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 5. In FIG. 5, the same parts as those in FIG. 2 are given the same numbers, and a feature is that a latch circuit 34 is provided in the circuit of FIG. 2. This latch circuit 34 is a circuit that takes in the output of the voltage comparator 17 to _I1 and outputs the signal to _O1 .
The outputs of the voltage comparators 17 and 14 at the moment when the voltage comparators 17 and 14 are closed are stored. That is, the solar radiation switch 7 is turned on, and once the latch circuit 34 connects the voltage comparators 17 and 1.
Once the output of 4 is memorized, the voltage comparators 17 and 1 will be connected again until the solar radiation switch 7 is opened and closed.
Even if the output of latch circuit 34 changes, the output of latch circuit 34 is O ₁
and O ₂ remain unchanged.

In this embodiment, the outputs of the voltage comparators 17 and 14 immediately after solar radiation are O 1 and O ₁ of the latch circuit 34, respectively.
_When the outside temperature changes after solar radiation, the resistance value of the thermistor 9 changes and the voltage comparators 17 and 14
Even if the output changes, the delay time set immediately after solar radiation does not change, and a delayed start time that corresponds to the season can be obtained.

Effects of the Invention As described above, according to the present invention, by storing the outside temperature immediately after solar radiation, which is not affected by solar radiation, etc., in a latch circuit, it is possible to change the seasonal This makes it possible to obtain an accurate delayed start time according to the requirements, and enables efficient operation of the HS.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a heat pump water heater, Fig. 2 is a circuit diagram of a conventional delayed start device for a heat pump water heater, Figs. 3 and 4 are sequence diagrams of the conventional circuit, and Fig. 5 is: FIG. 1 is a circuit diagram of a delayed start device for a heat pump water heater according to an embodiment of the present invention. 9... Thermistor, 17... Voltage comparator, 14
...Voltage comparator, 34...Latch circuit, 20...
Delay timer, 29...Transistor, 30...
...transistor, 32...relay, 33...relay.

Claims (1)

[Claims] 1. A DC power supply that supplies power; a voltage comparison circuit that extracts the signal of the temperature sensor as a voltage and compares the voltage with a reference voltage obtained by dividing the voltage by resistance;
A solar radiation switch that operates by detecting solar radiation, a latch circuit that holds the signal of the voltage comparison circuit at the same time that the DC power is turned on by the operation of the solar radiation switch, and a delay timer that outputs a signal after an arbitrary set time. A delay start device for a heat pump water heater, wherein the load is controlled by an AND output of a signal from the latch circuit and a signal from the delay timer.