JPH05256496A - Operation controller for air conditioner - Google Patents

Abstract

PURPOSE:To increase a capacity of a compressor corresponding to a room heating request capacity by preventing an operation of an auxiliary heater in the case of a low capacity of the compressor. CONSTITUTION:The operation controller for an air conditioner comprises a refrigerant circuit 9 in which a variable capacity compressor 1, an outdoor heat exchanger 3, a motor-driven expansion valve 5, and an indoor heat exchanger 6 are sequentially connected, and an auxiliary heater BH. The controller further comprises heater control means 11 for controlling ON/OFF the heater BH when becoming a predetermined air conditioning state. Further, the controller comprises control allowing means 12 for outputting a control allowance signal for controlling the heater BH when the capacity of the compressor 1 rises to a predetermined first allowance amount or more to the means 11. In addition, the controller comprises forcible stop means 13 for outputting a forcible stop signal for forcibly stopping the heater BH when the capacity of the compressor 1 decreases to a second capacity or lower than the first capacity to the means 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for an air conditioner, and more particularly to a measure for controlling an auxiliary heater.

[0002]

2. Description of the Related Art Conventionally, an air conditioner is sequentially connected to a compressor whose capacity is controlled by an inverter, a four-way switching valve, an outdoor heat exchanger, an electric expansion valve, and an indoor heat exchanger. , A cooling cycle and a heating cycle are configured to be capable of reversible operation. And, as disclosed in Japanese Utility Model Application Laid-Open No. 2-6913, some of the air conditioners have an auxiliary heater mounted in the vicinity of the indoor heat exchanger, resulting in insufficient heating capacity. If so, the auxiliary heater is turned on to compensate for the insufficient heating capacity.

[0003]

In the above-mentioned air conditioner, the auxiliary heater is conventionally controlled without any consideration of the capacity of the compressor. For example, when the temperature difference between the room temperature and the set temperature is 2 ° C. or more, it is determined that the heating capacity is insufficient, and the auxiliary heater is turned on, while when the temperature difference is 1 ° C. or less, the auxiliary heater is turned off. I was doing. However, this has a problem that the auxiliary heater continues to be turned on even though the refrigerant circuit has a heating capacity. That is, as shown in FIG. 5, the capacity of the compressor increases in accordance with the required heating capacity. However, if the capacity of the compressor is small, but the differential temperature is large, the auxiliary heater Since the compressor is turned on, the capacity of the compressor can be increased to increase the heating capacity, but the auxiliary heater continues to be turned on.

In particular, when the heating required capacity rises from a small state, the capacity of the compressor is essentially increased, but since the auxiliary heater is turned on, the capacity of the compressor does not increase, and the performance is improved. There was a problem that the coefficient (EER) was bad. Further, when the auxiliary heater is turned on in the start / stop area of the air conditioning operation, there is a problem that the start / stop number of the compressor increases.

The present invention has been made in view of the above problems, and prevents the operation of the auxiliary heater at a low capacity of the compressor so that the capacity of the compressor increases in accordance with the heating required capacity. The purpose is to reduce the number of times the compressor starts and stops.

[0006]

In order to achieve the above object, the means taken by the present invention is to make it possible to control the auxiliary heater in accordance with the capacity of the compressor.

Specifically, as shown in FIG. 1, the means taken by the invention according to claim 1 is as follows.
A heat source side heat exchanger (3), an expansion mechanism (5), and a use side heat exchanger (6), which are connected in this order to a refrigerant circuit (9) and an auxiliary heater (BH). It is premised on the air conditioner.

Further, there is provided heater control means (11) for on / off controlling the auxiliary heater (BH) in a predetermined air conditioning state. Further, when the capacity of the compressor (1) rises above a predetermined first capacity, a control permission signal for enabling control of the auxiliary heater (BH) is sent to the heater control means (11).
A control permission means (12) for outputting to is provided. In addition, the second capacity of the compressor (1) is lower than the first capacity.
A forced stop means (13) for outputting a forced stop signal for forcibly stopping the auxiliary heater (BH) to the heater control means (11) when the capacity falls below the capacity is provided.

The means taken by the invention according to claim 2 is the heater control means (11) in the invention according to claim 1 above.
Means that the temperature difference between the air temperature in the air-conditioning region and the set temperature is not less than the first temperature difference, and the saturation temperature equivalent to the condensation pressure is the predetermined first temperature.
When the temperature falls below the saturation temperature, the auxiliary heater (BH) is turned on, while the temperature difference becomes equal to or lower than the second temperature difference that is smaller than the first temperature difference, or the saturation temperature equivalent to the condensation pressure is higher than the first saturation temperature. When the temperature rises above the saturation temperature, the auxiliary heater (BH) is turned off.

[0010]

With the above structure, in the invention according to claim 1,
First, in the refrigerant circuit (9), for example, the liquid refrigerant condensed and liquefied in the use side heat exchanger (6) is decompressed by the expansion mechanism (5) and then evaporated in the heat source side heat exchanger (3). Then, it returns to the compressor (1) to perform heating operation.

During this heating operation, heater control means
(11) controls on / off of the auxiliary heater (BH) according to the operating state. Specifically, in the invention according to claim 2, the temperature difference between the air temperature and the set temperature in the air-conditioning region is the first. The temperature difference is equal to or more than the predetermined value, and the saturation temperature equivalent to the condensation pressure is the first predetermined value.
When the temperature falls below the saturation temperature, the auxiliary heater (BH) is turned on, while the temperature difference becomes equal to or lower than the second temperature difference that is smaller than the first temperature difference, or the saturation temperature equivalent to the condensation pressure is higher than the second saturation temperature. When the temperature rises above the saturation temperature, the auxiliary heater (BH) is turned off.

Further, when the capacity of the compressor (1) rises above a predetermined first capacity, for example, when the capacity of the compressor (1) rises above 1.1 times the rated capacity, the control permitting means (12) is used for the heater control means (1
The control permission signal is output to 1), and the heater control means (11) controls the on / off of the auxiliary heater (BH) according to the operating state as described above.

The forced stop means (13) is provided with the heater control means (1) when the capacity of the compressor (1) drops below a predetermined second capacity, for example, below 0.8 times the rated capacity.
The forced stop signal is output to 1), and the heater control means (11) turns off the auxiliary heater (BH) even in an operating state in which the auxiliary heater (BH) is turned on.

[0014]

Therefore, according to the inventions according to claims 1 and 2, when the capacity of the compressor (1) rises above the first capacity,
While enabling ON / OFF control of the auxiliary heater (BH), when the capacity of the compressor (1) drops below the second capacity, the auxiliary heater
Since the forced stop of (BH) is enabled, it is possible to reliably prevent the auxiliary heater (BH) from turning on at a low capacity of the compressor (1), so the capacity of the compressor (1) Can be increased in accordance with the heating required capacity. As a result,
Since the heating capacity of the refrigerant circuit (9) can be fully exerted, the coefficient of performance can be improved.

When the required heating capacity is small, the capacity of the compressor (1) is low, so that the auxiliary heater is used.
Since (BH) does not turn on, the number of times the compressor (1) is started and stopped can be reduced.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 shows a refrigerant piping system of an air conditioner to which the present invention is applied, which is a so-called separate type in which one indoor unit (B) is connected to one outdoor unit (A). Is.

The outdoor unit (A) includes a scroll type compressor (1) whose operating frequency is variably adjusted by an inverter, and a solid line in the figure during cooling operation and a broken line in the figure during heating operation. Four-way switching valve to replace (2)
And an outdoor heat exchanger that is a heat source side heat exchanger that functions as a condenser during cooling operation and as an evaporator during heating operation.
(3), a decompression section (20) for decompressing the refrigerant, and a compressor
An accumulator (7) for removing the liquid refrigerant in the suction refrigerant, which is provided in the suction pipe of (1), is arranged as a main device. Further, the indoor unit (B) is provided with an indoor heat exchanger (6) which is a utilization side heat exchanger that functions as an evaporator during cooling operation and as a condenser during heating operation. The compressor (1), the four-way switching valve (2), the outdoor heat exchanger (3), the pressure reducing section (20), the indoor heat exchanger (6), and the accumulator (7) are connected to the pipe ( 8) are connected sequentially,
A refrigerant circuit (9) is configured so that heat is transferred by circulating the refrigerant.

Here, the decompression section (20) includes a bridge-shaped rectifying circuit (8a) and a pair of connecting points in the rectifying circuit (8a).
A common path (8a) connected to (P, Q), and the common path (8a)
Includes a receiver (4) for storing the liquid refrigerant, an auxiliary heat exchanger (3a) for the outdoor heat exchanger (3), and an electric expansion mechanism that is an expansion mechanism that has a pressure reducing function and a flow rate adjusting function for the liquid refrigerant. Valve (5)
And are arranged in series. And the rectifying circuit (8a)
The other pair of connection points (R, S) in the
The piping (8) on the (3) side and the piping (8) on the indoor heat exchanger (6) side are connected. Furthermore, the rectifier circuit (8a) connects the upstream connection point (P) of the common path (8a) and the connection point (S) of the outdoor heat exchanger (3) side from the external heat exchanger (3). Indoor heat exchange with the first inflow passage (8b1) equipped with the first check valve (D1) that allows only refrigerant flow to the receiver (4), the upstream connection point (P) of the common passage (8a) The indoor heat exchanger (6) is connected to the connection point (R) on the side of the heat exchanger (6).
Second inflow path (8b2) equipped with a second check valve (D2) that allows only the flow of refrigerant from the receiver to the receiver (4), the downstream connection point (Q) of the common path (8a) and the indoor heat A first check valve (D3) that connects the connection point (R) on the exchanger (6) side and allows only the refrigerant to flow from the electric expansion valve (5) to the indoor heat exchanger (6). Outflow channel (8
c1), the downstream side connection point (Q) of the common path (8a) and the connection point (S) on the outdoor heat exchanger (3) side, and the electric expansion valve (5) to the outdoor heat exchanger (3). The second outflow passage (8c2) provided with the fourth check valve (D4) which allows only the refrigerant flow to (4).

Further, the common path (8
Between both connection points (P, Q) in a), the capillary tube (C)
A liquid seal prevention bypass passage (8f) is provided,
The liquid seal prevention bypass passage (8f) prevents liquid seal when the compressor (1) is stopped, while opening and closing between the upper part of the receiver (4) and the downstream side of the common passage (8a). A degassing passage (4a) equipped with a valve (SV) is connected. The degree of pressure reduction of the capillary tube (C) is set to be sufficiently higher than that of the electric expansion valve (5), and the function of adjusting the refrigerant flow rate by the electric expansion valve (5) during normal operation is maintained well. It is designed to be profitable.

Further, (F1 to F4) are filters for removing dust in the refrigerant, and (ER) is a silencer for reducing the operation noise of the compressor (1).

Further, the air conditioner is provided with sensors, (Thd) is a discharge pipe sensor (Tha) which is arranged in the discharge pipe of the compressor (1) and detects the discharge pipe temperature Td. Is
An outdoor suction sensor, which is located at the air suction port of the outdoor unit (A) and detects the suction air temperature Ta, which is the outside air temperature, (Thc)
Is located in the outdoor heat exchanger (3) and is an external heat exchange sensor that detects the external heat exchange temperature Tc that is the condensation temperature during cooling operation and the evaporation temperature during heating operation, and (Thr) is the indoor unit
The indoor suction sensor, which is located at the air inlet of (B) and detects the intake air temperature Tr that is the room temperature, (The) is located at the indoor heat exchanger (6), and becomes the evaporation temperature during cooling operation. An internal heat exchange sensor that detects the internal heat exchange temperature Te that becomes the condensation temperature that is the saturation temperature equivalent to the condensation pressure during heating operation, (HPS)
Is a high-pressure pressure switch that detects the high-pressure refrigerant pressure and outputs a high-voltage signal when the high-pressure refrigerant pressure rises excessively. (LPS) detects the low-pressure refrigerant pressure and detects the low-pressure refrigerant pressure. It is a low pressure switch that is turned on when it drops and outputs a low pressure signal.

The output signals of the sensors (Thd, ..., The) and switches (HPS, LPS) are output to the controller (10).
The controller (10) is configured to control the air conditioning operation based on the input signal.

In the above-mentioned refrigerant circuit (9), during the cooling operation, the liquid refrigerant condensed and liquefied in the outdoor heat exchanger (3) flows in from the first inflow passage (8b1), and the first check valve (D1) ) And then stored in the receiver (4), decompressed by the electric expansion valve (5), then evaporated in the indoor heat exchanger (6) through the first outflow path (8c1) and returned to the compressor (1). While circulating, during heating operation,
Liquid refrigerant condensed and liquefied in the indoor heat exchanger (6) flows in from the second inflow path (8b2), passes through the second check valve (D2), and is received.
After being stored in (4) and decompressed by the electric expansion valve (5), the second
Compressor by evaporating in the outdoor heat exchanger (3) via the outflow passage (8c2)
The cycle returns to (1).

Further, the indoor unit (B) has a built-in auxiliary heater (BH), and the auxiliary heater (BH) is turned on when the heating capacity is insufficient during heating operation. It is designed to supplement the heating capacity.

On the other hand, as a feature of the present invention, the controller (10) has a heater control means (11) for controlling the auxiliary heater (BH), a control permission means (12), and a forced stop means (1).
3) and are provided. The heater control means (11) performs on / off control of the auxiliary heater (BH) when in a predetermined air conditioning state, and specifically, the difference between the intake air temperature Tr, which is the air temperature in the air conditioning region, and the set temperature Ts. When the temperature ΔTr becomes equal to or higher than the first temperature difference and the internal heat exchange temperature Te, which is the condensation pressure equivalent saturation temperature, falls below the predetermined first saturation temperature, the auxiliary heater (BH) is turned on, that is, the differential temperature ΔTr becomes 2 When the internal heat exchange temperature Te exceeds 43 ° C, the auxiliary heater (BH) is turned on.
On the other hand, when the temperature difference ΔTr becomes equal to or lower than the second temperature difference which is smaller than the first temperature difference or when the internal heat exchange temperature Te rises above the second saturation temperature higher than the first saturation temperature, the auxiliary heater (BH) is turned off. That is, the temperature difference ΔTr becomes 1 ° C or less, or
When the internal heat exchange temperature Te exceeds 50 ° C., the auxiliary heater (BH) is turned off.

The control permission means (12) sends a control permission signal for controlling the auxiliary heater (BH) when the capacity of the compressor (1) rises above a predetermined first capacity. It is configured to output to the heater control means (11). That is, the controller (10) is provided with the capacity control means (14) of the compressor (1), and the capacity control means (14) is
The operating frequency of the inverter of the compressor (1) is divided into 20 steps N from zero to the maximum frequency, and each step N is set based on the discharge pipe temperature Td to control the capacity of the compressor (1). Configured, the rated capacity step Nt which is the preset rated capacity, for example, the rated capacity step Nt is 7,
When 1.1 times of 7 is set as the first capacity and the first capacity is exceeded, the control permission means (12) is configured to output a control permission signal to the heater control means (11). ..

When the capacity of the compressor (1) drops below the second capacity, which is lower than the first capacity, the forced stop means (13), for example, 0.8 times the rated capacity step Nt. When it is set to the second capacity and becomes lower than the second capacity, a forced stop signal for forcibly stopping the auxiliary heater (BH) is output to the heater control means (11).

Next, the control operation of the auxiliary heater (BH) will be described based on the control flow of FIG.

First, during heating operation, in step ST1, the control permission means (12) determines whether or not the capacity of the compressor (1) exceeds 1.1 times the rated capacity step Nt which is the first capacity. If the capacity of the compressor (1) is exceeded, a control permission signal for the auxiliary heater (BH) is output to the heater control means (11) and the determination in step ST1 is YES.

Subsequently, in step ST2, the heater control means (11) determines whether the temperature difference ΔTr between the intake air temperature Tr and the set temperature Ts is 2 ° C. or more, and the temperature difference ΔTr is 2 or more. If it is ℃ or more, the determination in step ST2 is YES, the process proceeds to step ST3, and the internal heat exchange temperature Te is the first saturation temperature 43.
C.-XH It is determined whether or not the temperature is lower than 1.degree. It should be noted that this XH1 ° C. is for correcting the first saturation temperature which is a criterion for judgment by the pipe length and the like, and is normally set to zero. Hereinafter, the first saturation temperature will be described as 43 ° C. To do.

When the internal heat exchange temperature Te is lower than 43 ° C., the determination in step ST3 is YES, the process proceeds to step ST4, and the heater control means (11) controls the control H.
The P decrease signal is output, specifically, the high pressure refrigerant pressure decrease signal is output to turn on the auxiliary heater (BH) to return, and the above-described operation is repeated.

That is, as shown in FIG.
In the case where the capacity of (1) is large and the temperature difference ΔTr is large and the internal heat exchange temperature Te is low, the heating required capacity is not reached even though the predetermined heating capacity is exhibited.
It is judged that the capacity is insufficient and the auxiliary heater (BH) is turned on.

On the other hand, in the step ST1, the control permission means (12) changes the capacity of the compressor (1) to the rated capacity step Nt.
If it is judged to be 1.1 times or less of No., the judgment becomes NO and the process moves to step ST5, where the forced stop means (13) is 0.8 times the rated capacity step Nt in which the capacity of the compressor (1) is the second capacity. If the capacity of the compressor (1) has decreased, it is determined YES in step ST5. Then, the process proceeds to step ST6, and it is determined whether or not the heater flag FH is set. The heater flag FH
Is set at the time of the first operation in the early morning of the heating operation, and is reset by the thermo-off. In the case other than the first heating operation of the first time, the determination in step ST6 is N.
When it becomes O, the process proceeds to step ST7, the heater flag FH is reset, and since it is currently reset, the process directly proceeds to step ST8.

In step ST8, the forced stop means (13) outputs a control HP rising signal, specifically, a high pressure refrigerant pressure rising signal to output the auxiliary heater (BH).
The forced stop signal is output to the heater control means (11), the heater control means (11) turns off the auxiliary heater (BH) and returns, and the above operation is repeated. That is,
As shown in FIG. 4, when the capacity of the compressor (1) is small, even if the temperature difference ΔTr is large and the internal heat exchange temperature Te is low, the auxiliary heater (BH) is on, Compressor
Since the capacity of (1) can be increased and a predetermined heating capacity can be exhibited, the auxiliary heater (BH) is turned off.

Further, the above-mentioned steps ST2 and ST3
In the above, even when the control permission means (12) is outputting the control permission signal of the auxiliary heater (BH), when the temperature difference ΔTr is lower than 2 ° C., or the inner heat exchange temperature Te is 43 ° C. If the temperature is higher than or equal to ℃, the determination is NO, and the heater control means (11) moves to step ST5 without turning on the auxiliary heater (BH). When the capacity of the compressor (1) is 1.1 times or less of the rated capacity step Nt and 0.8 times or more of the rated capacity step Nt, the determination in step ST5 is NO, Further, in the case of the first heating operation in the early morning, since the heater flag FH is set, the determination in step ST6 is YES, and steps ST5 and ST6 are repeated.
It will move to ST9. Then, the heater control means (1
1), the temperature difference ΔTr between the intake air temperature Tr and the set temperature Ts is 1 ℃
It is determined whether or not it is below, and if the temperature difference ΔTr is larger than 1 ° C,
The determination in step ST9 is NO, the process proceeds to step ST10, and it is determined whether the internal heat exchange temperature Te has risen above 50 ° C-XH1 ° C. In addition, this XH1 ℃ is the same as the above step ST3
Has the same meaning as, and is normally set to zero, and the second saturation temperature will be described below as 50 ° C.

When the internal heat exchange temperature Te is 50 ° C. or lower, the determination in step ST10 is NO, the process proceeds to step ST11, it is determined whether or not the heater flag FH is set, and the heater flag FH is determined. If is set, the process moves to step ST4 and the auxiliary heater (B
H) is turned on while the heater flag FH is reset, the current state is maintained and the process returns, and the above operation is repeated.

That is, the differential temperature ΔTr is larger than 1 ° C.,
When the internal heat exchange temperature Te is 50 ° C or lower, the auxiliary heater is used.
While (BH) is on, it continues to be on, while when the auxiliary heater (BH) is off, the off state is maintained. Also, in the case of the first operation in the early morning, when the temperature difference ΔTr is larger than 1 ° C. and the internal heat exchange temperature Te is 50 ° C. or less, the condition for turning on the auxiliary heater (BH) in step ST2 and step ST3 described above Even if the difference temperature ΔTr is 2 ° C. or higher and the internal heat exchange temperature Te is lower than 43 ° C., the auxiliary heater (BH) is turned on.

Further, the above-mentioned steps ST9 and ST11
In the above, the temperature difference ΔTr is 1 ° C. or less, or
If the internal heat exchange temperature Te is higher than 50 ° C., the determination becomes YES, the process proceeds to step ST7, the above-described operation is performed, and if the auxiliary heater (BH) is on, it is turned off. Become.

Therefore, according to this embodiment, the compressor
When the capacity of (1) rises above the first capacity, the auxiliary heater (B
H) can be turned on and off, but when the capacity of the compressor (1) drops below the second capacity, the auxiliary heater (BH) can be forcibly stopped. Then
Since it is possible to reliably prevent the auxiliary heater (BH) from turning on, the capacity of the compressor (1) can be increased corresponding to the heating required capacity. As a result, the refrigerant circuit (9)
Since it can fully demonstrate the heating capacity of
It is possible to improve the coefficient of performance.

When the required heating capacity is small, since the capacity of the compressor (1) is low, the auxiliary heater
Since (BH) does not turn on, the number of times the compressor (1) is started and stopped can be reduced.

Although the separate type air conditioner has been described in the present embodiment, it goes without saying that the present invention can be applied to various air conditioners.

Further, in this embodiment, the internal heat exchange sensor (The) is provided as the means for detecting the saturation temperature corresponding to the condensation pressure, but it goes without saying that it may be a pressure sensor or the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a refrigerant circuit diagram showing a refrigerant piping system of the air conditioner.

FIG. 3 is a control flow chart showing a control for reducing the capacity of a compressor.

FIG. 4 is a specific diagram showing the relationship between heating capacity and temperature difference.

FIG. 5 is a specific diagram showing a relationship between a conventional heating capacity and a differential temperature.

[Explanation of symbols]

 1 compressor 3 outdoor heat exchanger (heat source side heat exchanger) 5 electric expansion valve (expansion mechanism) 6 indoor heat exchanger (use side heat exchanger) 9 refrigerant circuit 10 controller 11 heater control means 12 control permission means 13 forced Stopping means 14 Capacity control means BH Auxiliary heater

Claims (2)

[Claims] 1. A refrigerant circuit (1) comprising a variable capacity compressor (1), a heat source side heat exchanger (3), an expansion mechanism (5) and a utilization side heat exchanger (6) connected in order. In an air conditioner equipped with 9) and an auxiliary heater (BH), a heater control means (11) for controlling on / off of the auxiliary heater (BH) when it is in a predetermined air conditioning state, and the compressor (1) A control permission means (12) for outputting a control permission signal for controlling the auxiliary heater (BH) to the heater control means (11) when the capacity rises above a predetermined first capacity, and the compressor When the capacity of (1) falls below the second capacity, which is lower than the first capacity, a forced stop signal for forcibly stopping the auxiliary heater (BH) is output to the heater control means (11). 13) An operation control device for an air conditioner, comprising: 2. The operation control device for an air conditioner according to claim 1, wherein the heater control means (11) makes the temperature difference between the air temperature and the set temperature in the air-conditioning region equal to or higher than the first temperature difference, and condenses. When the saturation temperature equivalent to the pressure falls below the predetermined first saturation temperature, the auxiliary heater (BH) is turned on, while the above-mentioned differential temperature is the first
The auxiliary heater (BH) is configured to be turned off when the second temperature difference is smaller than the temperature difference and is equal to or less than the second temperature difference, or when the saturation temperature corresponding to the condensation pressure is higher than the second saturation temperature higher than the first saturation temperature. A characteristic operation control device for an air conditioner.