JP3326898B2 - Control device for heat pump device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a heat pump device using a non-azeotropic mixed refrigerant.

[0002]

2. Description of the Related Art In recent years, mixed refrigerants have attracted attention as substitute refrigerants for heat pump devices in accordance with regulations on CFCs and HCFCs. An example of a conventional heat pump device using a non-azeotropic mixed refrigerant will be described below with reference to the drawings.

FIG. 9 shows a refrigeration cycle of a conventional heat pump apparatus using a non-azeotropic mixed refrigerant.

In FIG. 9, reference numeral 50 denotes a compressor, 51 denotes a four-way valve, 52 denotes an indoor heat exchanger, 53 denotes an expansion valve, and 54 denotes an outdoor heat exchanger, which are sequentially connected in a ring to form a main circuit. .

The operation of the heat pump device configured as described above will be described below.

The high-temperature and high-pressure refrigerant vapor compressed by the compressor 50 releases heat in the indoor heat exchanger 52 via the four-way valve 51 to be condensed and liquefied. Thereafter, the refrigerant is decompressed and expanded by the expansion valve 53 to become a low-temperature low-pressure refrigerant. And, the outdoor heat exchanger 54
After the heat is absorbed and evaporated and vaporized, the refrigerant becomes low-temperature and low-pressure refrigerant vapor, compressed by the compressor 50 again, and the heat pump cycle is repeated (for example, JP-A-3-13766). At this time, a plate-fin type heat exchanger as shown in FIG. 6 is generally used as the heat exchanger. In this heat exchanger, a large number of fins 62 are fixed at equal intervals to a heat transfer tube 61, and air flows in a direction indicated by an arrow A with respect to a refrigerant flowing in an arrow B direction.
It is configured to flow in a direction and to flow crossing each other vertically.

[0007]

[SUMMARY OF THE INVENTION However in the heating operation, as in the case of using a single refrigerant 7, once the heat exchanger when the air at room temperature T _a which passes the outdoor heat exchanger (evaporator) and while exiting the T _a1 next heat exchanger, non-azeotropic mixed refrigerant as shown in FIG. 8, the temperature of even a phase change to equal pressure change is a saturated liquid refrigerant temperature because it depends on the concentration of saturated Since the temperature of the vapor refrigerant is different and the temperature of the saturated liquid refrigerant is lower than the temperature of the saturated vapor refrigerant, the refrigerant has a non-isothermal property. Therefore, heat exchange occurs with the air while the temperature rises. Becomes uneven at each value of the outdoor heat exchanger.As a result, the non-azeotropic mixed refrigerant has the same temperature in the case of a single refrigerant but has a large difference in boiling point between the low-boiling refrigerant and the high-boiling refrigerant. And the inlet refrigerant temperature is higher than the outlet refrigerant temperature. Also becomes low. Therefore, in the above configuration, when the outdoor temperature becomes considerably low during the heating operation, when the non-azeotropic mixed refrigerant is used even under the condition that the single refrigerant does not frost on the outdoor heat exchanger, the outdoor heat exchanger is used. There was a problem of frost formation.

The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to prevent frost formation on an outdoor heat exchanger.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, a control device for a heat pump apparatus according to the present invention is provided with a non-azeotropic mixture.
A main circuit in which a variable capacity compressor, a four-way valve, an indoor heat exchanger, a first expansion valve, a gas-liquid separator, a second expansion valve, and an outdoor heat exchanger are connected in a ring using a combined refrigerant ; The refrigeration cycle having an injection circuit provided with a two-way valve in the middle of the pipe from the gas-liquid separator gas side outlet and the outdoor heat exchanger outlet to the variable capacity compressor suction, during heating operation,
Compressor operating frequency detecting means for detecting and outputting the operating frequency of the variable displacement compressor; first comparing means for comparing the operating frequency with a frequency set value and outputting a control signal; and the outside air temperature detection means detects and outputs an output mode that this compares the outdoor air temperature and the set outdoor air temperature, and controls the second comparison means for outputting a control signal, the 2-way valve opening and closing Storage means for storing
The signal generated by the first comparing means is "operating frequency".
Is greater than the frequency set value ".
The signal generated by the second comparing means is "the outdoor air temperature is
When the temperature is lower than the set outdoor air temperature,
The "open" operation of the two-way valve is performed in accordance with the output mode described above . Further, the control device of the heat pump device of the present invention
Uses a non-azeotropic refrigerant mixture, a variable capacity compressor,
Valve, indoor heat exchanger, first expansion valve, gas-liquid separator, second
A main circuit in which an expansion valve and an outdoor heat exchanger are connected in a ring,
From the gas-side outlet of the gas-liquid separator and the outlet of the outdoor heat exchanger,
A two-way valve is provided in the middle of the pipe leading to the variable displacement compressor suction
Refrigeration Cycle with Improved Injection Circuit
And, during the heating operation, by detecting the outdoor heat exchanger refrigerant temperature
Outdoor heat exchanger refrigerant temperature detecting means to output, and this outdoor heat
Comparison of exchanger refrigerant temperature and set outdoor heat exchanger refrigerant temperature
A third comparing means for outputting a control signal, and the two-way valve
Storage means for storing the output mode for controlling the opening and closing of
The signal generated by the third comparing means is "outdoor heat exchange".
The unit refrigerant temperature is lower than the set outdoor heat exchanger refrigerant temperature. ''
The two modes according to the output mode of the storage means.
This performs the "open" operation of the valve. In addition, the heat of the present invention
The control unit of the pump unit uses a non-azeotropic mixed refrigerant,
Variable displacement compressor, 4-way valve, indoor heat exchanger, first expansion
Valve, gas-liquid separator, second expansion valve, outdoor heat exchanger
Connected main circuit, gas-liquid separator gas side outlet and the chamber
Distribution from the outside heat exchanger outlet to the suction of the variable capacity compressor
Has an injection circuit with a two-way valve in the middle of the pipe
The refrigeration cycle comprises a variable capacity type during heating operation.
Compressor operating frequency that detects and outputs the operating frequency of the compressor
Compare the operating frequency with the frequency setting value
And a first comparing means for outputting a control signal;
Outdoor heat exchanger refrigerant temperature that detects and outputs the exchanger refrigerant temperature
Temperature detection means, the outdoor heat exchanger refrigerant temperature and the set outdoor heat
A third method for comparing with the exchanger refrigerant temperature and outputting a control signal
Comparing means and an output mode for controlling the opening and closing of the two-way valve;
Storing means for storing, wherein the first comparing means generates
Signal is "The operating frequency is greater than the frequency set value."
And the signal generated by the third comparing means is
`` The outdoor heat exchanger refrigerant temperature is set higher than the outdoor heat exchanger refrigerant temperature
Lower than the degree), the output mode of the storage means
Accordingly, the "open" operation of the two-way valve is performed. Also,
The control device of the heat pump device of the present invention is a non-azeotropic mixed cooling
Medium, variable capacity compressor, four-way valve, indoor heat exchanger,
First expansion valve, gas-liquid separator, second expansion valve, outdoor heat exchange
A main circuit in which the separators are connected in a ring, and a gas side outlet of the gas-liquid separator.
From the outlet and the outlet of the outdoor heat exchanger.
Injection with a two-way valve in the middle of the pipe leading to the inlet
Constitute a refrigeration cycle having a circuit, during heating operation,
Compression that detects and outputs the operating frequency of a variable displacement compressor
Machine operating frequency detection means, this operating frequency and frequency setting
First comparing means for comparing the value with a value and outputting a control signal;
Outdoor air temperature detection means that detects and outputs outdoor air temperature
And compare this outdoor air temperature with the set outdoor air temperature,
A second comparing means for outputting a control signal;
Outdoor heat exchanger refrigerant temperature detection that detects and outputs the unit refrigerant temperature
Outlet means, the outdoor heat exchanger refrigerant temperature and the set outdoor heat exchange
Third comparison of comparing with the refrigerant temperature of the heater and outputting a control signal
Means and an output mode for controlling opening and closing of the two-way valve.
Storage means, and a signal generated by the first comparison means.
No. is "Operation frequency is larger than frequency set value".
And the signal generated by the second comparing means is "room".
The outside air temperature is lower than the set outdoor air temperature. "
The signal generated by the third comparing means is "outdoor heat exchanger cold".
The medium temperature is lower than the set outdoor heat exchanger refrigerant temperature. ''
The two-way valve according to the output mode of the storage means.
An "open" operation is performed.

[0010]

According to the present invention, the following functions are provided by the above-described structure.

That is, a first expansion valve, a gas-liquid separator, and the like are provided in a pipe extending from the indoor heat exchanger outlet to the outdoor heat exchanger inlet.
By providing a second expansion valve and providing an injection circuit provided with a two-way valve in the middle of the pipe from the gas-liquid separator gas side outlet and the outdoor heat exchanger outlet to the variable capacity compressor suction,
The refrigerant flowing out from the liquid-side outlet of the gas-liquid separator changes the state from (f) to (g) in FIG. 4 in the intermediate pressure state, and then the pressure drops and moves to (h). Therefore, the refrigerant temperature at the inlet of the outdoor heat exchanger is increased by ΔT, and the temperature difference between the inlet and the outlet of the outdoor heat exchanger becomes smaller than when the injection circuit is not provided and the operation proceeds from (f) to (k). Therefore, the non-isothermal property of the mixed refrigerant can be further reduced, and frost formation on the outdoor heat exchanger can be prevented.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a refrigeration cycle diagram in the control device of the heat pump device of the present invention.

In FIG. 1, reference numeral 1 denotes a variable displacement compressor;
Is a four-way valve, 3 is an indoor heat exchanger, 4 is a first expansion valve, 5 is a gas-liquid separator, 6 is a second expansion valve, 7 is an outdoor heat exchanger,
They are sequentially connected in a ring to form a main circuit. A two-way valve 9 is provided in the injection circuit 8 that connects the gas-side outlet of the gas-liquid separator and the pipe from the outdoor heat exchanger outlet to the suction of the variable displacement compressor.

FIG . 2 is an electric circuit diagram of the heat pump device shown in FIG. In the figure, 21 is a power switch, 22 is a frequency detector for detecting the compressor operating frequency, 23 is a temperature detector for detecting the refrigerant temperature of the outdoor heat exchanger, 24
Is a temperature detector for detecting the outdoor temperature, 25 is an A / D
The conversion device 26 is a microcomputer (hereinafter referred to as an LSI), and includes an input circuit 27, a CPU 28, a memory 2
9, an output circuit 30 is provided. The input circuit 27 includes a frequency detector 22 and an outdoor heat exchanger refrigerant temperature detector 23.
And the output of the outdoor temperature detector 24 is the A / D converter 2
5 is input. Numeral 31 denotes an electromagnetic coil for opening and closing the two-way valve 32 according to the output of the output circuit 30.

Here, the block diagram shown in FIG. 3 and the electronic control circuit shown in FIG. 2 will be described.
Reference numeral 2 denotes a compressor operating frequency detecting means for detecting and outputting the operating frequency of the compressor of FIG.
Is an outdoor heat exchanger refrigerant temperature detecting means for detecting and outputting the refrigerant temperature of the outdoor heat exchanger, and the temperature detector 24 of FIG. 2 is an outdoor air temperature detecting means for detecting and outputting the outdoor air temperature. Correspondingly, the LSI 26 of FIG. 2 compares a value detected by the compressor operating frequency detecting means, the outdoor heat exchanger refrigerant temperature detecting means, and the outdoor air temperature detecting means with a set value and outputs a control signal. First and second
And third comparing means, storing means for storing an output mode for controlling the opening and closing of the two-way valve, and an output of the storing means based on output signals generated from the first, second and third comparing means. It corresponds to a selecting means for selecting one of the modes. The electromagnetic coil 31 that opens and closes the two-way valve 32 in FIG. 2 corresponds to the output unit in FIG.

In the above configuration, the configuration and operation of the control circuit during operation of the heat pump device will be described with reference to FIG. FIG. 5 is a flowchart showing a program of the heat pump device stored in the memory 29 of the LSI 26. As can be seen from this flowchart, in the present invention, the two-way valve 9 is controlled to be opened only under the following conditions a) to c) which are considered to cause frost formation.

A) The compressor operating frequency f is f ₁ (for example, 9
If higher than 8 Hz) b) outdoor air temperature T _r is T ₁ (e.g., 4 ° C.) than lower case c) If the remote control the outdoor heat exchanger refrigerant temperature T _e is lower than T ₂ (e.g., 2 ° C.) or, When an operation instruction is issued by forced operation or the like, the operation of the heat pump device starts. At the runs step 40 shown in FIG. 5 simultaneously, the compressor operation frequency detecting means detects the operating frequency, further performs a comparison operation between the value f the rated frequency f _1, if f> f ₁ " Y
"ES" is determined, and step 41 is executed. f
≦ If f ₁ second output mode of the memory circuit by the selection means of the built-in memory 29 proceeds to step 44 by determining "NO" is selected, the energization of the electromagnetic coil 31 is controlled signal from the output circuit 30 is output Is stopped and the two-way valve 9 is closed. If T _r <T ₁ by the comparison operation between the outdoor air temperature T _r and setting the outdoor air temperature T ₁ of the determination "YES" is made, the first memory circuit by the selection means of the memory 29 built proceeds to step 43 After the output mode is selected, a control signal is output from the output circuit 30 and the electromagnetic coil 31 is energized to open the two-way valve 9.

Next, if f ≦ f ₁ , the process proceeds to step 42 with a determination of “NO”, a comparison operation between the outdoor heat exchanger refrigerant temperature _Te and the set refrigerant temperature T ₂ is performed, and _Te <T ₂ If so, a determination of "YES" is made, and the process proceeds to step 43, where the first output mode of the storage circuit is selected by the selection means built in the memory 29, an output is output from the output circuit 30, and the electromagnetic coil 31 is energized. After the valve 9 is opened, step 40
Return to

If T _e ≧ T ₂ , the determination at “NO” proceeds to step 44, where the second output mode of the storage circuit is selected by the selecting means built in the memory 29, and the output circuit 3
When a control signal is output from 0, energization of the electromagnetic coil 31 is stopped, and the two-way valve 9 is closed.

A case in which none of the above conditions a) to c) are satisfied after the start of operation will be described. At this time, the control signal is output by the compressor operation detecting means, the outdoor air temperature detecting means, and the outdoor heat exchanger inlet refrigerant temperature detecting means of the LSI 26, and the second output mode of the storage circuit is selected by the selecting means in the memory 29. , Output circuit 30
Then, the control signal is output, the energization of the electromagnetic coil 31 is stopped, and the two-way valve 9 is closed. Therefore, the refrigerant flowing into the gas-liquid separator 5 flows only through the main circuit without flowing through the injection circuit 8 under conditions other than those under which frost formation may occur.

Next, a case where the two-way valve 9 is opened again will be described. The two-way valve 9 opens when the conditions a) and b) are simultaneously satisfied or when the conditions a) and c) are simultaneously satisfied. At this time, the first output mode of the storage circuit is selected by the selection means built in the memory 29, an output is output from the output circuit 30, and the electromagnetic coil 31 is energized. As a result, the two-way valve 9 opens.

When the two-way valve 9 is opened, the refrigerant flows into the gas-liquid separator 5.
The high-boiling-point-rich vapor refrigerant flows through the injection circuit 8 and the high-boiling-point-rich liquid refrigerant flows through the outdoor heat exchanger 7, so that the outdoor heat exchanger is compared with the case without the injection circuit 8. Inlet temperature rises,
Since the difference in refrigerant temperature between the inlet and the outlet of the outdoor heat exchanger 7 is reduced, frost formation on the heat exchanger 5 can be prevented.

[0024]

As is apparent from the above embodiment, the control device of the heat pump apparatus according to the present invention comprises a first expansion valve, a gas-liquid separator, and a pipe in the middle of the pipe extending from the indoor heat exchanger outlet to the outdoor heat exchanger inlet. , A second expansion valve, and an injection circuit having a two-way valve in the middle of a pipe from the gas-side outlet of the gas-liquid separator and the outlet of the outdoor heat exchanger to the suction of the variable displacement compressor. The refrigerant flowing out from the separator liquid side outlet changes state from (f) to (g) in FIG.
Then, the pressure drops and moves to (h). Therefore, the refrigerant temperature at the inlet of the outdoor heat exchanger is increased by about ΔT, and the difference between the refrigerant temperatures at the inlet and the outlet of the outdoor heat exchanger is smaller than when the injection circuit is not provided and the process proceeds from (f) to (q). Therefore, the non-isothermal property of the mixed refrigerant can be further reduced,
It is possible to prevent frost formation on the outdoor heat exchanger.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of a refrigeration apparatus showing a first embodiment of the present invention.

FIG. 2 is a control circuit diagram embodying a control device of the device.

FIG. 3 is a block diagram showing the control device by function realizing means;

FIG. 4 is a characteristic diagram showing a state of a refrigerant in each composition of a non-azeotropic mixed refrigerant.

FIG. 5 is a flowchart of the control device.

FIG. 6 is a schematic diagram of the overall configuration of a plate-fin tube type heat exchanger.

FIG. 7 is a characteristic diagram showing the state of heat exchange between the air temperature and the refrigerant temperature at the position of each heat transfer tube when heat exchange is performed by a single refrigerant.

FIG. 8 is a characteristic diagram showing a state of heat exchange between the air temperature and the refrigerant temperature at the position of each heat transfer tube when heat exchange is performed by a non-azeotropic mixed refrigerant.

FIG. 9 is a refrigeration cycle diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Variable capacity compressor 2 4-way valve 3 Indoor heat exchanger 4 First expansion valve 5 Gas-liquid separator 6 Second expansion valve 7 Outdoor heat exchanger 8 Injection circuit 9 2-way valve

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Watanabe 1006 Kazuma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-60-140048 (JP, A) JP-A-4- 327761 (JP, A) JP-A-3-102140 (JP, A) JP-A-62-280557 (JP, A) JP-A-62-280556 (JP, A) JP-A-62-280555 (JP, A) JP-A-57-198968 (JP, A) JP-A-61-186064 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 47/02 510

Claims (4)

(57) [Claims] 1. A variable displacement compressor, a four-way valve, an indoor heat exchanger, a first expansion valve, a gas-liquid separator, a second expansion valve, and an outdoor heat exchanger using a non-azeotropic mixed refrigerant. A main circuit connected in an annular shape, and two pipes from the gas side outlet of the gas-liquid separator and the outlet of the outdoor heat exchanger to the suction of the variable displacement compressor.
A refrigeration cycle having an injection circuit provided with a side valve, a compressor operating frequency detecting means for detecting and outputting an operating frequency of the variable displacement compressor during a heating operation, and an operating frequency and a frequency set value. And a first comparing means for outputting a control signal, an outdoor air temperature detecting means for detecting and outputting an outdoor air temperature, and comparing the outdoor air temperature with a set outdoor air temperature to output a control signal. and second comparison means includes a storage means for storing an output mode for controlling said two-way valve opening and closing, said first comparing means calling for
The generated signal indicates that the operating frequency is larger than the set frequency.
And the signal generated by the second comparing means.
No. "Outdoor air temperature is lower than set outdoor air temperature"
The two modes according to the output mode of the storage means.
Heat pump device characterized by performing "open" operation of valve
Control device. 2. A variable displacement compression using a non-azeotropic mixed refrigerant.
, Four-way valve, indoor heat exchanger, first expansion valve, gas-liquid separation
Main circuit in which a vessel, a second expansion valve, and an outdoor heat exchanger are connected in a ring shape
Path, the gas-side separator gas side outlet and the outdoor heat exchanger.
In the middle of the pipe from the mouth to the suction of the variable capacity compressor
Refrigeration cycle with injection circuit provided with one-way valve
During the heating operation, the outdoor heat exchanger refrigerant temperature is
An outdoor heat exchanger refrigerant temperature detecting means for detecting and outputting
The outdoor heat exchanger refrigerant temperature and the set outdoor heat exchanger refrigerant temperature
And a third comparing means for comparing and outputting a control signal.
Storage means for storing an output mode for controlling opening and closing of a two-way valve
And the signal generated by the third comparing means is “outdoor heat”
The exchanger refrigerant temperature is lower than the set outdoor heat exchanger refrigerant temperature
Is in accordance with the output mode of the storage means.
Heat pon characterized by performing "open" operation of two-way valve
Control device for the control device. 3. A variable capacity compressor, a four-way valve, an indoor heat exchanger, a first expansion valve, a gas-liquid separator, a second expansion valve, and an outdoor heat exchanger using a non-azeotropic mixed refrigerant. A main circuit connected in an annular shape, and two pipes from the gas side outlet of the gas-liquid separator and the outlet of the outdoor heat exchanger to the suction of the variable displacement compressor.
A refrigeration cycle having an injection circuit provided with a side valve, a compressor operating frequency detecting means for detecting and outputting an operating frequency of the variable displacement compressor during a heating operation, and an operating frequency and a frequency set value. comparing a first comparison means for outputting a control signal, an outdoor heat exchanger refrigerant temperature detection means which detects and outputs the outdoor heat exchanger refrigerant temperature, set outdoor heat with the outdoor heat exchanger refrigerant temperature A third comparing means for comparing the temperature with the exchanger refrigerant and outputting a control signal; and a storing means for storing an output mode for controlling opening and closing of the two-way valve , wherein the first comparing means is provided. Is generated.
If "the operating frequency is larger than the frequency set value"
In both cases, the signal generated by the third comparing means is "outdoor heat".
The exchanger refrigerant temperature is lower than the set outdoor heat exchanger refrigerant temperature
Is in accordance with the output mode of the storage means.
Heat pon characterized by performing "open" operation of two-way valve
Control device for the control device. 4. A variable displacement compression using a non-azeotropic mixed refrigerant.
, Four-way valve, indoor heat exchanger, first expansion valve, gas-liquid separation
Main circuit in which a vessel, a second expansion valve, and an outdoor heat exchanger are connected in a ring shape
Path, the gas-side separator gas side outlet and the outdoor heat exchanger.
2 in the middle of the pipe from the mouth to the suction of the variable capacity compressor
Refrigeration cycle with injection circuit provided with one-way valve
When the heating operation is performed, the variable displacement compressor operates.
Compressor operating frequency detecting means for detecting and outputting the frequency
And the operation frequency and the frequency set value, and
First comparing means for outputting a signal, and detecting the outdoor air temperature.
Outdoor air temperature detecting means for outputting air temperature and this outdoor air temperature
And the set outdoor air temperature, and outputs the control signal.
(2) comparing the outdoor heat exchanger refrigerant temperature with the comparing means
Outdoor heat exchanger refrigerant temperature detecting means to output, and this outdoor heat
Comparison of exchanger refrigerant temperature and set outdoor heat exchanger refrigerant temperature
A third comparing means for outputting a control signal, and the two-way valve
Storage means for storing the output mode for controlling the opening and closing of
The signal generated by the first comparing means is "operating frequency".
Is greater than the frequency set value ".
The signal generated by the second comparing means is "the outdoor air temperature is
Lower than the set outdoor air temperature ”or the third comparative method.
The signal generated by the stage indicates that the outdoor heat exchanger refrigerant temperature is set
When the temperature is lower than the outdoor heat exchanger refrigerant temperature,
Perform the "open" operation of the two-way valve according to the output mode of the means
Heat pump equipment characterized by that Control device.