JPS5934936B2 - heat source device - Google Patents

Description

Detailed Description of the Invention The present invention varies the capacity of a refrigeration cycle heat source device that compresses refrigerant using a compressor for refrigerant compression and this motor according to the load, and also introduces step control in the middle as necessary. By doing so, the compressor is controlled to start and stop, thereby stabilizing its operation, increasing its lifespan, and improving its comfort and controllability.

Furthermore, by adding an inverter or the like that drives the compressor motor at a frequency higher than the commercial power supply frequency, the aim is to reduce the size of the compressor, the size of the motor, and the weight of the motor while maintaining the same refrigerating capacity.

Conventionally, there has been a method of changing the capacity in stages by changing the number of poles of the compressor motor (2P04P), but this method has the disadvantage that it is not possible to perform proportional control of the capacity depending on the load.

Another idea is to operate the compressor motor at variable speed using an inverter, etc., and proportionally control the refrigerating capacity, but proportional capacity control alone has various problems, especially the operating method, which makes it difficult to maintain stable operation of the equipment, compressor, etc. There were problems with the machine's lifespan, vibration comfort, etc.

Hereinafter, the configuration and operation will be explained based on the accompanying drawings, which are one embodiment of the present invention.

FIG. 1 shows an embodiment using a heat source device such as a heat pump type that heats and cools by a refrigeration cycle, and the figure shows an application to a separate air conditioner.

1 is an outdoor unit of a separate air conditioner, 2 is an indoor unit, and the outdoor unit 1 includes a compressor 3, a motor 4 that drives the compressor 3, a four-way valve 5, a capillary tube 6, and an outdoor heat exchanger 7. , has an outdoor fan 8.

The indoor unit 2 includes an indoor heat exchanger 9 and an indoor fan 10, and the indoor fan 10 circulates the air in the air-conditioned room to perform heating, cooling, etc.

The four-way valve 5 is used to switch between heating and cooling by changing the refrigerant circulation method.

11 is a commercial power supply, 12 is an operation switch, 13 is a motor 4
It is the main source of the choke input, which is full-wave rectified by a diode group 14 and smoothed by a choke coil 15 and a capacitor 16.

A chopper 17 receives pulse power from terminals 17a and 17b from a control circuit to be described later, chops the transistor 18 at a predetermined frequency and duty, and smooths it using a choke 19 and a capacitor 20.

Diode 21 is a freewheel diode, and 22 is a diode for protecting the transistor 18.

Reference numeral 23 denotes an inverter, in which transistors 24 to 29 are turned on and off at a mutually determined period, and three-phase power is applied to the motor 4.

Diodes 30-35 are diodes for protecting transistors 24-29.

36 is a control power supply, which includes a transformer 37 and a diode group 3.
8, the voltage is stepped down, full-wave rectified, and smoothed by a capacitor 39.

As described above, the present invention uses the control block described below to control the chopper 17 depending on the load state (refrigeration capacity state).
0 frequency - The voltage applied to the motor is controlled by changing the duty, and the motor 4 is controlled by changing the drive frequency of the inverter 23 using this voltage. This control block introduces staircase control, and this control block will be explained below.

The output voltage of the control power supply 36 is taken out from terminals E and F,
This voltage causes the comparator 40 to operate.

The comparator 40 has, for example, a thermistor connected to a terminal 40a to detect the room temperature of a room heated or cooled by the indoor unit 2, and sets this terminal voltage to vTh.

Further, a volume (such as a variable resistor) for adjusting the room temperature is connected to the terminal 40b, and the terminal voltage is set to Vad.

The comparator 40 has a difference ΔV between the respective terminal voltages.
a=V a d -V T h is processed as shown in FIG.

That is, in FIG. 2, when the horizontal axis is the deviation ΔVa and the vertical axis is the output Va, the following relationship is established.

(1) When the deviation ΔVa is in the interval (Δv4 to ΔV3), the output Va is proportional to the deviation ΔVa.

(2) The deviation ΔVa is (Δv3 to ΔV2) and (+Δv
1 to -Δvt), the output Va is either Va3 or Va2(
When the deviation value goes from small to dog), it is fixed to val and does not change.

(3) During the period of deviation, ΔVa<−ΔV1, the output Va becomes zero.

(4) Next, when the deviation ΔVa returns from -Δ■1 to +Δv1, the output Va switches from zero to Va, and then 1
-Go through the process of 4.

As mentioned above, (Δv3 ~ ΔV2) and (+Δv1 ~ -
Δv1), a dead zone, that is, hysteresis H is provided.

This output is output from 41 and enters a comparator 42 of the current limiter.

The comparator 42 has an input terminal 44 of the battery sensor 43, and when a current higher than a predetermined current flows, the comparator 42
It has the function of limiting and lowering the output Va of.

Therefore, normally the voltage Va at the output terminal 41 of the comparator 40 (output in FIG. 2) becomes the output 45 of the comparator 42 and enters the chopper driver 46.

The chopper driver 46 changes the on/off duty of the outputs 17a and 17b under constant frequency conditions according to the input voltage Va (output from the terminal 45), or changes the off time while keeping the on time constant. , that is, by varying the output frequency or controlling the output terminal 17a.
, 17b.

Therefore, the chopper 17 is chopped by its transistor 18, and the input voltage Va of the chopper driver 46 is
A voltage VO is applied between the outputs C and D of the chopper 17 in proportion to
D is taken out.

That is, the input voltage of the comparator 40, ΔVa=(
When Vd-VTh) is large, the output voltage VcD of the chopper 17 is large, and vice versa, it is small.

This means that the output voltage VOD of the chopper 17 is Va in FIG.
This means that the lightning voltage is proportional.

Next is the drive section of the inverter 23, and the chopper 17.
The voltage-frequency (V
OD-f) converter 48 whose output frequency f is taken off at terminal 49 and enters a ring counter 50.

The output frequency-divided and controlled by the ring counter 50 is applied to the transistor groups 24 to 29 of the inverter 23, and the transistors are switched alternately with phases shifted by 120 degrees, and this three-phase power is applied to the motor 4.

An example of the result of driving a compressor at high speed using the circuit shown in FIG. 1 is shown.

FIG. 3 shows an example of about 1.5 horsepower, where curve 7 is the operating torque characteristic of the compressor 3, xi 7X2 j x3, etc. is the characteristic of the torque and rotation speed of the motor 4.

When using the circuit shown in FIG. 1, for example, the comparator 40
When the input vad-VTh-ΔVamax, the torque characteristic of the motor 4 by the inverter 23 is X1%,
This is the intersection with the y% characteristic, which is the operating torque of the compressor 3.

Rotates at approximately 11,000 Orp.

Next, when the room temperature rises and the deviation value of the comparator 40 reaches Δv3, the Moh characteristic becomes an X2 curve, and about 60
The motor 4 rotates at 0 Orpm.

The motor 4 rotates on the X2 curve until the deviation value reaches ΔV2 in FIG. 2. When the deviation reaches Δv2, the output of the comparator 40 decreases from Va3 to va2. Therefore, X2' in Fig. 3
Jump onto a curve (stair descent).

By this operation, if there is a mechanical resonance point in the compression system including the motor 4, this jumping operation can avoid the resonance point and reduce noise.

When it becomes smaller, that is, exceeds the set value, it becomes the X3 curve and rotates at about 200 rpm, and beyond this point, the motor 4 stops based on the output characteristics of the comparator 40 shown in FIG.

Thereafter, control is performed according to the characteristics shown in FIG.

Figure 4 shows the characteristics of the refrigerating capacity of compressor 3.
This figure shows how the capacity changes in response to the rotational speed of the motor 4 shown in the figure.

FIG. 5 shows the comparator 40 in FIG. 1, which rotates the motor 4 at high speed when the device starts operating when the operation switch 120 is turned on, produces a high refrigerating capacity at startup, and thereafter performs rapid control according to the load. The present invention relates to other means of stair control for heating and cooling to improve comfort, controllability, and usability.

In the case of FIG. 5, the comparator 40 has the following functions.

In other words, when the operation switch is turned on, the capacity adjustment terminal 4
0b voltage Vad and, for example, a thermistor for room temperature detection (
The terminal voltage vThO (not shown) is Δv1 shown in FIG.
When the difference is larger than that, there is a drive command for the compressor 3, that is, it is assumed to be in the "H" state, and an R-8 type flip-flop, for example, is set to forcibly set the deviation ΔV4.

As a result, the output of the comparator 40 becomes Va4 shown in characteristic 1 in FIG.

Therefore, the inverter 23 runs at the highest frequency and the compressor 3
is performing at its best.

Then, when the deviation becomes lower than ΔV, comparator 4
0 operates as a switch, and its output drops to val in FIG.

This allows it to rotate at its lowest rotational speed and capacity.

In some cases (when the deviation reaches 1 ΔV), the output of the comparator 40 becomes zero and the motor 4 stops.

After that, when the setting of the adjustment knob is changed or the load becomes heavier and the deviation becomes larger than Δ■1, the deviation changes according to the G% characteristic shown in FIG. 5.

By using the comparator 40 having such a function, it is possible to rapidly operate with no power only at the time of startup, and then return to normal control.

FIG. 6 shows another embodiment, which is a combination of the embodiments shown in FIGS. 2 and 5. In addition, several staircase control units may be introduced in the variable area as necessary. is a matter of course.

The heat source device of the present invention has the following excellent effects.

(1) The capacity of the refrigeration cycle heat source device can be varied according to the load, and if necessary, jump operation can be performed in a stepwise manner only in a predetermined section in the range of change from the maximum rotation speed to the minimum rotation speed of the compressor. This allows the resonance points of the equipment to be avoided and noise to be reduced, and there is no need to design a special airframe structure.

(2) In the above-mentioned item 1, if the jumping motion is controlled by detecting the resonance of the aircraft, all the variations in the resonance of the aircraft can be absorbed, which is even more effective.

(3) When the operation switch is turned on, the motor 4 is rotated at high speed to set the capacity of the compressor 3 to the maximum speed, and after reaching a certain deviation, the refrigerating capacity is variable controlled according to the load. Characteristics during startup can be improved, leading to improvements in comfort, usability, and controllability.

(4) By rotating the motor at a frequency higher than the commercial frequency, it is possible to downsize the heat source device that constitutes the compression system.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a heat source device in an embodiment of the present invention,
Figure 2 is a characteristic diagram of comparator deviation value and output, Figure 3 is a motor operating characteristic diagram, Figure 4 is a compressor capacity characteristic diagram, and Figures 5 and 6 are comparator deviations of other embodiments. It is a characteristic diagram of value and output. 1... Outdoor unit, 2... Indoor unit, 3... Compressor, 4... Motor,
5... Four-way valve, 6... Capillary tube, 7... Outdoor heat exchanger, 9... Indoor heat exchanger, 11...・Commercial power supply, 17...
...Chopper, 23...Inverter, 40.4
2... Comparator, 46... Chopper driver, 48... Voltage/frequency converter, 5
0...Ring counter.

Claims (1)

[Scope of Claims] 1. A compressor for compressing refrigerant, a motor for driving the compressor, a heat exchanger section for absorbing and dissipating heat from the refrigerant compressed by the compressor in a condensing section, an evaporating section, etc., and a refrigerant A refrigeration cycle is formed with the expansion section, and an inverter power source is used as a power source for the drive motor of the compressor, and the input voltage and output frequency of the inverter are stopped depending on the capacity adjustment knob, etc., and the load condition. An inverter control means is provided which enables variable speed operation of the compressor motor from a set high speed rotation to a minimum speed rotation, and has a stepwise control region having appropriate hysteresis in the section of the variable speed operation region. A heat source device characterized in that: 2. As a control means for the inverter that serves as the power source for the drive motor of the compressor, a comparator with a hysteresis function is provided to perform stepwise control in the motor settings - from the highest speed rotation to the lowest speed rotation, and the output of this comparator 2. The heat source device according to claim 1, wherein the resonance and noise of the refrigeration device are reduced by controlling the voltage and frequency of the inverter. 3. As a control means for the inverter that is the power source for the drive motor of the compressor, when the power is turned on, it detects the capacity setting value such as the capacity adjustment knob and the load condition, and when it exceeds a predetermined deviation value, it detects the deviation value. Regardless of the value, the motor rotates at the highest speed, and then when the deviation value reaches a predetermined deviation value or less, the motor rotates at the lowest speed, and from then on, the motor is provided with a comparator that drives the motor in proportion to the deviation value. The heat source device according to claim 1, characterized in that: