JPH034819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a heat pump type heat collecting device that uses solar heat and air heat as heat sources.

<Prior art> Conventionally, in a heat collecting device using solar heat or air heat as a heat source using a heat pump, a method for controlling the compressor capacity is to detect the outside temperature and increase the rotation speed of the compressor as the outside temperature increases. Methods are being considered to control this so that it becomes lower. This method is effective for reducing the power consumption of the compressor and improving the build-up coefficient of the equipment, but since the heating capacity is affected by outside air conditions, it may not reach the target boiling temperature, or the hot water may not reach the target boiling temperature. Even in the evening, when the amount of hot water used is high, there may be cases where the boiling water is not completed, which is inconvenient from the point of view of hot water usage.

<Purpose> In view of the above, the present invention aims to provide a solar heat/air heat collector that can reliably use hot water at a target boiling temperature at a target boiling time.

<Example> An example of the present invention will be described below with reference to FIGS. 1 and 2. This includes a compressor 1 that compresses and discharges a heat medium, and a compressor connected to the discharge side of the compressor. A heat collection circuit 5 is constituted by a condenser 2 and a heat collector 4 whose one side is connected to the condenser 2 via a throttle device 3 and the other side is connected to the compressor 1, and is a hot water storage tank for storing the fluid to be used. 6 and a working fluid heater 8 arranged outside the hot water storage tank 6 via a circulation pump 7 and having a heat exchange relationship with the condenser 2 are connected to each other to form a fluid heat circuit 9. In the compressor 1, the capacity is variable, a first temperature detector 11 is provided at the inlet of the fluid heater 8, and a second temperature sensor 12 is provided at the outlet of the fluid heater 8. A plurality of third temperature detectors 15 are provided for detecting the temperature of the fluid in the hot water storage tank 6 at the start of operation, and the first,
A control circuit 13 is provided that controls the capacity of the compressor 1 based on the output signals of the second and third temperature detectors 11, 12, and 15. Detects the fluid temperature in the hot water storage tank at the start of operation, and calculates the target heating capacity from the temperature difference between the detected temperature and the target boiling temperature, and the heat collection operation time from the start of operation to the target boiling time. In addition, the heating capacity of the heat collecting circuit 5 is calculated from the temperatures detected by the first and second temperature detectors 11 and 12, and the heating capacity of the compressor 1 is adjusted so that the heating capacity becomes the target heating capacity. It is configured to output a capacity control signal to the

In FIG. 1, the heat collector 4 is composed of a pipe equipped with black-painted fins, and is capable of collecting solar heat and air heat. Further, the compressor 1 has a variable rotation speed by a frequency conversion circuit 14. Further, as the throttle device 3, an expansion valve driven by a stepping motor is used. The expansion valve 3 controls the flow rate of the heat medium using a temperature sensor (not shown) installed at the entrance and exit of the heat collector 4 so that the heat collection in the heat collector 4 is performed under optimal conditions. On the other hand, the fluid heating circuit 9 is formed by sequentially connecting a hot water tank 6, a circulation pump 7, a fluid heater 8, and a hot water storage tank 6. The condenser 2 and the fluid heater 8 are held in a heat exchange relationship, forming, for example, a double tube heat exchanger 10. and the control circuit 1
3 is a target boiling temperature setting means 20a for setting a target boiling temperature, and a target boiling time setting means 20 for setting a target boiling time.
The heating load is calculated based on the difference between the fluid temperature in the hot water storage tank at the start of operation from the third temperature detector 15 and the target boiling temperature from the target boiling temperature setting means 20a. heating load calculation means 21a, a heat collection operation time which is the difference between the operation start time and the target boiling time from the target boiling time setting means 20b, and a heating load from the heating load calculation means 21a. The operation start target heating capacity calculation means 21b calculates the target heating capacity at the start of operation, and the heating capacity is calculated from the detected temperature difference from the first temperature detector 11 and the second temperature detector 12. A main control circuit comprising a heating capacity calculation means 21c for calculating the target heating capacity, and a comparison calculation means 21d for comparing and calculating the target heating capacity from the target heating capacity calculation means 21b and the heating capacity from the heating capacity calculation means 21c. 13A and the comparison calculation means 2 of the main control circuit 13A.
Based on the output signal from 1d, the rotation speed of the compressor is lowered when the heating capacity is greater than the target heating capacity,
It is comprised of a frequency conversion circuit 14 that outputs an operating frequency signal to the compressor 1 so as to increase the rotation speed of the compressor when the heating capacity is smaller than the target heating capacity.

The main control circuit 13A is, for example, a general one-chip microcomputer that stores data internally.
It has RAM, program ROM, ALU, etc., and is driven by a clock oscillation circuit. Further, the frequency conversion circuit 14 is, for example, an inverter circuit, and outputs a signal for converting the three-phase AC power frequency of the compressor motor. Further, the temperature detectors 11, 12, and 15 are, for example, thermistors, and the voltage drop detected by the thermistors due to temperature changes is converted into a digital value and input to the main control circuit 13A.

Note that the target heating capacity can be determined as follows.
In other words, the target heating capacity is determined by the difference between the fluid temperature (water temperature) in the hot water tank at the start of operation and the target boiling temperature, the heating load that can be calculated from the hot water tank capacity, the start time of operation, and the target boiling time. Calculated from the heat collection operation time, which is the difference between

Heating load = (Target boiling temperature - Fluid temperature in the hot water storage tank at the start of operation) × Hot water storage tank capacity Target heating capacity = Heating load / Heat collection operation time Next, the heat collection action will be explained. The high-temperature, high-pressure heating medium gas compressed by the compressor 1 flows into the condenser 2, and fluid (water) flows through the fluid heater 8 in a heat exchange relationship.
It exchanges heat, condenses and liquefies, and reaches the expansion valve 3. When passing through the expansion valve 3, it expands adiabatically and is depressurized, becoming a low-temperature, low-pressure unevaporated heat medium. The heat medium then flows into the heat collector 4, absorbs solar heat and air heat, is gasified, and enters the compressor 1 again to repeat the above cycle. On the other hand, the water in the hot water storage tank 6 is sent to the fluid heater 8 by the circulation pump 7, heated and heated, and then flows into the hot water storage tank 6.

At this time, the temperatures at the inlet and outlet of the fluid heater 8 are input to the main control circuit 13A from the first and second temperature detectors 11 and 12, and in the main control circuit 13A, the temperatures at the inlet and outlet of the fluid heater 8 are adjusted to a constant temperature in advance. The heating capacity is constantly detected using the set water flow rate.
Then, the control circuit is based on the temperature difference between the fluid temperature in the hot water storage tank at the start of operation and the target boiling temperature detected by the third temperature detector 15, and the heat collection operation time from the start of operation to the target boiling time. 13, the target heating capacity is calculated using the method described above, and the main control circuit 13A is
to be memorized.

Then, the rotation speed of the compressor 1 is controlled according to changes in outside air conditions so as to achieve the target heating capacity stored in the main control circuit 13A.

To explain this control in detail based on Figure 2, heating capacity>target heating capacity (heating load/heat collection operation time)
In this case, the fluid temperature in the hot water storage tank 6 will reach the target boiling temperature by the target boiling time, so the rotation speed of the compressor 1 is lowered and control is performed so that the target boiling temperature is reached at the target boiling time. do. Also,
If heating capacity < target heating capacity, the fluid temperature in the hot water storage tank 6 will not reach the target boiling temperature by the target boiling time, so the rotation speed of the compressor 1 will be increased to reach the target temperature at the target boiling time. Control the boiling temperature.

In other words, if the amount of heat collected by the heat collector 4 increases due to the increase in solar radiation, outside temperature, etc., the rotation speed of the compressor 1 will be lowered to reduce the amount of work of the compressor 1, that is, the power consumption, thereby achieving a high coefficient of performance. drive with Also, if the sunlight, outside temperature, etc. become low, the rotation speed of compressor 1 will be increased to
Increase the amount of work done and operate to achieve the target heating capacity.

Therefore, hot water at the target boiling temperature can be reliably used at the target boiling time, and when the sunlight or outside temperature is high, the target heating capacity can be reduced to reduce the load on the compressor. , economical operation becomes possible.

<Effects> As is clear from the above description, the present invention includes a compressor that compresses and discharges a heat medium, a condenser connected to the discharge side of the compressor, and one side of which compresses and discharges the heat medium through a throttle device. A heat collection circuit is constituted by a heat collector connected to a condenser and the other side connected to the compressor, a hot water storage tank for storing a working fluid, and a working fluid that is in a heat exchange relationship with the condenser outside the hot water storage tank. In a heat collection device in which a fluid heating circuit is configured by connecting heaters to each other,
The compressor is of a variable capacity type, and a first temperature sensor is provided at the inlet of the fluid heater, and a second temperature sensor is provided at the outlet of the fluid heater, and the temperature of the fluid in the hot water storage tank is determined by the compressor. A third temperature detector is provided to detect the target boiling temperature, and a control circuit is provided to control the capacity of the compressor based on the output signals of the first, second, and third temperature detectors. target boiling temperature setting means for setting the temperature; target boiling time setting means for setting the target boiling time; and the fluid temperature in the hot water storage tank at the start of operation and the target from the third temperature detector. heating load calculation means that calculates the heating load based on the difference between the target boiling temperature from the boiling temperature setting means, and the difference between the operation start time and the target boiling time from the target boiling time setting means. operation start target heating capacity calculation means for calculating a target heating capacity at the start of operation based on the heat collection operation time and the heating load from the heating load calculation means; and the first temperature detector and the second temperature detector. A heating capacity calculation means that calculates the heating capacity from the temperature difference detected by the temperature detector, and a comparison calculation between the target heating capacity from the target heating capacity calculation means and the heating capacity from the heating capacity calculation means. Based on the output signal from the comparison calculation means, the rotation speed of the compressor is lowered when the heating capacity is larger than the target heating capacity, and the rotation speed of the compressor is lowered when the heating capacity is smaller than the target heating capacity. and a frequency conversion circuit that outputs an operating frequency signal to the compressor so as to increase the rotational speed of the compressor when .

Therefore, according to the present invention, the fluid temperature in the hot water storage tank at the start of operation can be detected by the third temperature detector, and the heating load is calculated from the difference between this detected temperature and the target boiling temperature, and the heating load is calculated from the temperature difference between this detected temperature and the target boiling temperature. The target heating capacity is detected from the temperature load and the heat collection operation time from the start of operation to the target boiling time, and the heating capacity is detected from the detected temperature difference from the first and second temperature detectors, The compressor operation can be controlled by comparing the target heating capacity with the heating capacity, so hot water at the target boiling temperature can be obtained almost every day at the target boiling time, and when the solar radiation and outside temperature are high, the compressor operation can be controlled by comparing the target heating capacity with the heating capacity. Since the heating capacity can be reduced and the load on the compressor can be reduced, economical operation is possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a solar/air heat collector showing an embodiment of the present invention, FIG. 2 is a control flowchart of the same, and FIG. 3 is a functional block diagram of the same. 1: Compressor, 2: Condenser, 3: Squeezing device, 4:
Heat collector, 5: Heat collection circuit, 6: Hot water storage tank, 7: Circulation pump, 8: Heater, 9: Heating circuit, 10: Heat exchanger, 11, 12: Temperature detector, 13: Control circuit,
13A: Setting device, 13B: Main control circuit, 14: Frequency conversion circuit, 15: Third temperature detector, 20a:
Target boiling temperature setting means, 20b: Target boiling time setting means, 21a: Heating load calculation means, 2
1b: Target heating capacity calculation means at the start of operation, 21
c: heating capacity calculation means, 21d: comparison calculation means.

Claims (1)

[Claims] 1. A compressor that compresses and discharges a heat medium, a condenser connected to the discharge side of the compressor, one side connected to the condenser via a throttle device, and the other side connected to the compressor. A heat collection circuit is constituted by a heat collector connected to the machine, and a hot water storage tank that stores the working fluid and a working fluid heater that is in a heat exchange relationship with the condenser outside the hot water storage tank are connected to each other. In the heat collection device configured with a fluid heating circuit, the compressor is of a variable capacity type, and a first temperature sensor is provided at the inlet of the fluid heater, and a second temperature sensor is provided at the outlet of the fluid heater. a third temperature detector for detecting the temperature of the fluid in the hot water storage tank; and a control circuit for controlling the capacity of the compressor based on the output signals of the first, second, and third temperature detectors. The control circuit includes: target boiling temperature setting means for setting a target boiling temperature; target boiling time setting means for setting a target boiling time; and from the third temperature detector. heating load calculation means for calculating a heating load based on the difference between the fluid temperature in the hot water storage tank at the start of operation and the target boiling temperature from the target boiling temperature setting means; and the operation start time and the target boiling time setting. Target heating capacity calculation at the start of operation to calculate the target heating capacity at the start of operation based on the heat collection operation time which is the difference from the target boiling time from the means and the heating load from the heating load calculation means means, heating capacity calculation means for calculating heating capacity from the detected temperature difference from the first temperature detector and the second temperature detector; and target heating capacity and heating from the target heating capacity calculation means. Comparison calculation means for comparing the heating capacity from the capacity calculation means; and based on the output signal from the comparison calculation means, when the heating capacity is greater than the target heating capacity, the rotation speed of the compressor is reduced; A heat collection device comprising: a frequency conversion circuit that outputs an operating frequency signal to the compressor so as to increase the rotation speed of the compressor when the heating capacity is smaller than the target heating capacity.