JP2000088363A - Heat pump type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To draw out performance of an indoor heat exchanger at the time of a cooling operation at a maximum limit. SOLUTION: A pulse type motor driven expansion valve EV is fully opened, and a compressor 1 is started to be driven. A temperature difference Δt between an inlet and an outlet from an indoor outlet piping temperature t2 and an indoor inlet piping temperature t1 at the time of elapsing a predetermined time Δτis set to a first reference temperature difference Δto1, and a result obtained by subtracting the difference Δto1 from the difference Δt during continuously operating of the compressor 1 thereafter is set as a sensed supercooling degree SH. Then, an opening of the valve EV is decreased so that the sensed degree SH becomes a first predetermined sensed supercooling degree SH1 or more, and when the degree SC becomes the first degree SC1 or more, the opening p1s1 of the valve EV is contrarily set to a large value by a first predetermined opening Δp1s1. Accordingly, a refrigerant supercooling degree of an outlet of an indoor heat exchanger 1 is not largely assured, but substantially supercooling degree SH=0 is approached, and hence the performance of the exchanger can be achieved to a maximum limit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle for maximizing the performance of an indoor heat exchanger in a cooling operation of a heat pump type air conditioner using air as a heat source.

[0002]

2. Description of the Related Art Heat pump type air conditioners are
Various developments have already been made.
The basic technology of a heat pump air conditioner as disclosed in JP-A-204568 will be described below.

As shown in FIG. 12, the conventional heat pump type air conditioner is composed of one outdoor unit A and three indoor units B1, B2, B3.

The outdoor unit A includes a compressor 1, an inverter INV, and an outdoor heat exchanger 3. The indoor unit B1 includes an expansion valve EV1, an indoor heat exchanger 17, a first temperature sensor Th11, and a second temperature sensor Th21. Similarly, the indoor unit B2 and the indoor unit B3 also have the expansion valve EV2, the indoor heat exchanger 27, the first temperature sensor Th12, the second temperature sensor Th22, and the expansion valve EV3, respectively. Device 37, first temperature sensor Th13,
It comprises a second temperature sensor Th23.

[0005] The outdoor unit A and the indoor units B1, B2, B3 are communicated with each other by refrigerant pipes, and the compressor 1, the outdoor heat exchanger 3, the expansion valve EV1, and the indoor heat exchanger 1 are connected.
7. The compressor 1 is connected to the compressor 1 in an annular manner by a refrigerant pipe, and the expansion valve E1 and the expansion valve E are connected in parallel to the indoor heat exchanger 17.
V2, the indoor heat exchanger 27, the expansion valve EV3, and the indoor heat exchanger 37 are connected to form a refrigeration cycle.

A first temperature sensor Th is provided at the outlet of each expansion valve EV1, EV2, EV3 in the indoor units B1, B2, B3 and at the outlet of each indoor heat exchanger 17, 27, 37.
11, Th12, Th13, and second temperature sensor Th2
1, Th22, Th23, and the indoor unit B
1, room temperature sensor 3 for detecting room temperature near B2, B3
13 and 23 are provided.

The operation of the heat pump type air conditioner configured as described above will be described.

First, in the cooling operation, the refrigerant flows in the direction of the solid line arrow in the figure to form a cooling cycle, and the outdoor heat exchanger 3 is used as a condenser, and the indoor heat exchangers 17, 27, and 37 are used as evaporators. Let it work.

In the above cooling cycle, the high-temperature and high-pressure gas refrigerant that has exited the compressor 1 is condensed in the outdoor heat exchanger 3 to become a high-temperature and high-pressure liquid refrigerant. It is distributed to B2 and B3 and flows in,
The refrigerant which has been decompressed and expanded by each of the expansion valves EV1, EV2, EV3 and has become a two-phase refrigerant is supplied to the indoor heat exchangers 17, 27, 37.
Absorbs heat from indoor air by evaporating (cooling operation)
Repeat the cycle of doing.

The control device detects the room temperature of each room by using the room temperature sensors 3 and 1.
The refrigerant is detected according to 3, 23, and the refrigerant is distributed according to the heat load of each room. The temperatures of the inlets of the expansion valves EV1, EV2, EV3 are measured by the first temperature sensors Th11, Th12, Th13, and the temperatures of the outlets of the indoor heat exchangers 17, 27, 37 are measured by the second temperature sensors Th21, Th22, Th23. By measuring, the degree of superheat is calculated for each of the indoor heat exchangers 17, 27, 37.

If there is an indoor unit having a degree of superheat deficiency, the degree of opening of the expansion valve of the indoor unit is reduced to adjust the amount of refrigerant circulated, maintain the degree of superheat, and always operate at the optimum degree of superheat. enable.

[0012]

However, in the above-mentioned conventional structure, when the pressure loss in the pipe between the outlet of the expansion valve and the outlet of the indoor heat exchanger is large, the expansion valves EV1, EV2, EV are used.
The temperature difference between the inlet and outlet of the indoor heat exchangers 17, 27 and 37 and the temperature of the outlets of the indoor heat exchangers 17, 27 and 37,
There is a drawback that the degree of superheat at the outlet of 37 cannot be represented, and the degree of superheat at the outlet of the indoor heat exchangers 17, 27, and 37 cannot be calculated accurately.

That is, when there are a plurality of refrigerant paths (hereinafter, referred to as refrigerant paths) in the indoor heat exchangers 17, 27, and 37, a refrigerant flow divider for dividing the refrigerant for each refrigerant path is provided. It is necessary to install between expansion valves EV1, EV2, EV3 and the indoor heat exchangers 17, 27, 37.

[0014] Since the refrigerant flow divider is composed of a plurality of small tubes having an inner diameter smaller than the diameter of the collecting pipe at the inlet and outlet of the expansion valve, the pressure loss at that portion is large and cannot be neglected.

Alternatively, there is always a pressure loss in each refrigerant path in the indoor heat exchanger body, and it cannot be ignored when calculating the degree of superheat.

When the pressure loss as described above exists, the pressures at the inlets of the expansion valves EV1, EV2, EV3 (saturation pressure because the refrigerant is in a two-phase state) are changed by the indoor heat exchanger 17,
It does not correspond to the saturation pressure at the outlet of 27,37.

Therefore, when the pipe pressure loss between the expansion valve outlet and the indoor heat exchanger outlet is large, the expansion valve EV
1, the temperature of the inlet of EV2, EV3 and the indoor heat exchanger 17,
The difference between the inlet and outlet temperatures of the outlets of the indoor heat exchangers 17, 27 and 37 does not indicate the degree of superheat at the outlets of the indoor heat exchangers 17, 27 and 37. There was a drawback that the degree could not be calculated.

Further, in the above-mentioned conventional configuration, the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger is ensured in order to stably control the cooling cycle. The superheat of the refrigerant at the outlet of the vessel is in a saturated vapor state,
That is, when the superheat degree is almost zero, the performance possessed by the heat exchanger can be maximized.

Therefore, the present invention solves the conventional problem. Even when the pressure loss in the pipe between the outlet of the expansion valve and the outlet of the indoor heat exchanger is large, the pressure loss is not affected by the magnitude of the pressure loss. It is an object of the present invention to provide a heat pump type air conditioner that can simply and accurately calculate the degree of superheat at an outlet of an indoor heat exchanger and can maximize the performance possessed by the indoor heat exchanger in a cooling operation. .

[0020]

In order to achieve this object, the present invention provides, as a first technical means, an outdoor unit comprising a compressor, an outdoor heat exchanger, an outdoor blower, and an expansion valve; And an indoor unit including an indoor heat exchanger and an indoor blower, and sequentially includes the compressor, the outdoor heat exchanger, the expansion valve, the refrigerant flow divider, the indoor heat exchanger, and the compressor. In a cooling cycle in which a refrigerant pipe is connected in a ring to circulate the refrigerant, at the start of operation of the compressor in the cooling mode, the expansion valve is fully opened, and thereafter, when a predetermined time has elapsed from the start of operation of the compressor. The temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature at the inlet and outlet is defined as a first reference temperature difference, and the difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature during the subsequent continuation of the operation of the compressor is calculated from the inlet / outlet temperature difference. The result of subtracting the first reference temperature difference is defined as a detected superheat degree, and the opening degree of the expansion valve is reduced until the detected superheat degree becomes equal to or more than a first predetermined superheat degree. An opening larger by a first predetermined opening than the opening of the expansion valve at the time when the degree of superheating or more is obtained is obtained, and the obtained opening is used as the opening of the subsequent expansion valve. .

Thus, it is possible to detect the net degree of superheat at the outlet of the indoor heat exchanger by subtracting the influence of the pressure loss in the pipe between the inlet of the refrigerant distributor and the outlet of the indoor heat exchanger. In addition, the refrigerant superheat degree at the outlet of the indoor heat exchanger functioning as an evaporator is not largely secured, and it is possible to approach a saturated vapor state, that is, a state where the superheat degree is almost zero. That the performance possessed can be maximized,
Control close to the ideal state can be realized.

As a second technical means, in the first technical means, a difference between an inlet / outlet pipe temperature and an indoor / outlet pipe temperature at a time when a predetermined time has elapsed from the start of operation of the compressor is used as a reference. By replacing the temperature difference portion with the reference temperature difference obtained by adding a predetermined temperature difference to the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature, the refrigerant flow divider inlet and the indoor It is possible to correct the difference that occurs in the saturation temperature difference of the refrigerant corresponding to the pressure loss in the pipe between the outlet of the heat exchanger and the heat exchanger.

That is, the difference between the saturation temperature difference after the elapse of a predetermined time from the start of the compressor and the saturation temperature difference at the time when the opening degree of the expansion valve is reduced after the elapse of the predetermined time is determined by the second temperature.
By adding to the reference temperature difference, the degree of superheat detected at the outlet of the indoor heat exchanger can be accurately detected.

Further, as a third technical means, in addition to the second technical means, after the opening degree of the expansion valve is set, the detected superheat degree is not less than a second predetermined superheat degree which is smaller than the first predetermined superheat degree. In some cases, the opening of the expansion valve is set to be larger by a second predetermined opening, and when the detected superheat is smaller than 0, the opening of the expansion valve is set to be smaller by the second predetermined opening. By doing so, the opening degree of the expansion valve can be controlled so that the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger, which varies according to the cooling load in the room, is kept close to zero, so that even if the cooling load fluctuates, It is possible to realize a control close to an ideal state in which the performance possessed by the exchanger can be maximized.

As a fourth technical means, in addition to the first technical means, when the compressor is temporarily stopped and restarted in the cooling cycle after the opening degree of the expansion valve is set, the expansion valve may be used. The opening is set to be larger by a third predetermined opening than the opening of the expansion valve immediately before the compressor is stopped, and the operation of the compressor is restarted. The inlet / outlet temperature difference between the indoor inlet pipe temperature and the indoor outlet pipe temperature at the time when a predetermined time has elapsed is defined as a third reference temperature difference, and the indoor outlet pipe temperature and the indoor inlet pipe temperature during the subsequent continuation of operation of the compressor. By subtracting the third reference temperature difference from the entrance / exit temperature difference as a new detected superheat degree, the indoor cooling load changes, and the amount of refrigerant circulating in the cooling cycle fluctuates. The third reference temperature It is possible to correspond to the change.

That is, after the compressor is changed from the operating state to the stopped state, for example, when the indoor temperature has reached the set temperature, or when the refrigeration cycle is in an abnormal operation state and the protection control is operated in the refrigeration cycle, etc. When the operation of the compressor is started again, the opening degree of the expansion valve immediately before the stop of the compressor is set to be larger by a third predetermined opening degree, the compressor is restarted, and the pipe temperature detecting means By updating the third reference temperature difference, which is the difference between the inlet / outlet pipe temperature and the indoor / outlet pipe temperature detected by the above, the operation control corresponding to the change in the refrigerant load in the room becomes possible.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 comprises an outdoor unit comprising a compressor, an outdoor heat exchanger, an outdoor blower and an expansion valve, a refrigerant diverter, an indoor heat exchanger and an indoor blower. An indoor unit, and the compressor,
In a cooling cycle in which the outdoor heat exchanger, the expansion valve, the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in an annular manner by a refrigerant pipe to circulate the refrigerant, the expansion valve and the refrigerant flow are divided. An indoor inlet pipe temperature sensor installed in a refrigerant pipe between the heat exchanger, an indoor outlet pipe temperature sensor installed in an outlet collective pipe of the indoor heat exchanger, the indoor inlet pipe temperature sensor, and the indoor outlet pipe temperature sensor A pipe temperature detecting means for converting an output from the compressor into a temperature signal, an operating mode detecting means for detecting an operating mode of the cooling cycle, and a time detecting means for outputting a signal when a predetermined time has elapsed from the start of operation of the compressor. Compressor control means for operating / stopping the compressor, expansion valve control means for controlling the degree of opening of the expansion valve, pipe temperature detection means, operation mode detection means, and time detection And a first control means for controlling the compressor control means and the expansion valve control means based on a signal from the first stage. The first control means detects a cooling mode by the operation mode detection means. At the time, the expansion valve is fully opened by the expansion valve control means, the compressor control means starts the operation of the compressor, and then the time detection means determines that a predetermined time has elapsed from the start of operation of the compressor. An inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means at the time of detection is defined as a first reference temperature difference, and the pipe temperature detecting means during the subsequent continuation of operation of the compressor The result obtained by subtracting the first reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the above is regarded as a detected superheat degree, and the detected superheat degree is a first predetermined superheat. Degree, the opening degree of the expansion valve is reduced by the expansion valve control means, and the opening degree of the expansion valve at the time when the detected degree of superheat becomes equal to or more than the first predetermined degree of superheating is set to a first degree. An opening degree larger by a predetermined opening degree is obtained, and the expansion valve control means is controlled so that the obtained opening degree becomes a subsequent opening degree of the expansion valve.

According to the above configuration, the saturated temperature difference of the refrigerant corresponding to the pressure loss in the pipe between the inlet of the refrigerant distributor and the outlet of the indoor heat exchanger is detected as the first reference temperature difference within a predetermined time after the start of the compressor. By subtracting the first reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature after a lapse of a predetermined time, the pressure loss in the pipe between the inlet of the refrigerant distributor and the outlet of the indoor heat exchanger is reduced. The net degree of superheat at the outlet of the indoor heat exchanger from which the influence of the above has been subtracted can be detected.

Further, since the superheat degree of the refrigerant at the outlet of the indoor heat exchanger functioning as an evaporator is not sufficiently secured, it is possible to approach a saturated vapor state, that is, a state of superheat degree = 0. It is possible to realize a control close to an ideal state in which the performance of the heat exchanger can be maximized.

[0030] The invention according to claim 2 provides an outdoor unit comprising a compressor, an outdoor heat exchanger, an outdoor blower and an expansion valve, and an indoor unit comprising a refrigerant diverter, an indoor heat exchanger and an indoor blower. And the compressor, the outdoor heat exchanger, the expansion valve, the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in a loop with a refrigerant pipe to circulate a refrigerant. In the cycle, an indoor inlet pipe temperature sensor installed on a refrigerant pipe between the expansion valve and the refrigerant flow divider, an indoor outlet pipe temperature sensor installed on an outlet collective pipe of the indoor heat exchanger, and the indoor inlet pipe A temperature sensor, a pipe temperature detecting means for converting an output from the indoor outlet pipe temperature sensor into a temperature signal, an operation mode detecting means for detecting an operation mode of the cooling cycle, and an operation start of the compressor. A time detecting means for outputting a signal when a predetermined time has elapsed, a compressor controlling means for operating / stopping the compressor, an expansion valve controlling means for controlling an opening degree of the expansion valve, and the pipe temperature detecting means. A second control unit that controls the compressor control unit and the expansion valve control unit based on signals from the operation mode detection unit and the time detection unit, wherein the second control unit When the cooling mode is detected by the mode detection means, the expansion valve is fully opened by the expansion valve control means, the operation of the compressor is started by the compressor control means, and then the operation of the compressor is started by the time detection means. A predetermined temperature difference is added to an entrance / exit temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means at the time when it is detected that a predetermined time has elapsed from the start of operation. The result is defined as a second reference temperature difference, and the second reference temperature difference is subtracted from an inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means during the subsequent operation of the compressor. The obtained result is regarded as a detected degree of superheat, and the expansion valve control means decreases the degree of opening of the expansion valve until the detected degree of superheat becomes greater than or equal to a first predetermined degree of superheat. The expansion valve control means obtains an opening that is larger than the opening of the expansion valve by a first predetermined opening at the time when the expansion valve reaches a predetermined opening, and sets the obtained opening to a subsequent opening of the expansion valve. Is controlled.

According to the above configuration, it is possible to correct a difference in a saturation temperature difference of the refrigerant corresponding to a pipe pressure loss between the inlet of the refrigerant distributor and the outlet of the indoor heat exchanger. That is, the difference between the saturation temperature difference after the elapse of a predetermined time from the start of the compressor and the saturation temperature difference when the opening degree of the expansion valve is reduced after the elapse of the predetermined time is added to the second reference temperature difference. This makes it possible to accurately detect the degree of superheat detected at the outlet of the indoor heat exchanger.

The invention according to claim 3 provides an outdoor unit including a compressor, an outdoor heat exchanger, an outdoor blower, and an expansion valve, and an indoor unit including a refrigerant diverter, an indoor heat exchanger, and an indoor blower. And the compressor, the outdoor heat exchanger, the expansion valve, the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in a loop with a refrigerant pipe to circulate a refrigerant. In the cycle, an indoor inlet pipe temperature sensor installed on a refrigerant pipe between the expansion valve and the refrigerant flow divider, an indoor outlet pipe temperature sensor installed on an outlet collective pipe of the indoor heat exchanger, and the indoor inlet pipe A temperature sensor, a pipe temperature detecting means for converting an output from the indoor outlet pipe temperature sensor into a temperature signal, an operation mode detecting means for detecting an operation mode of the cooling cycle, and an operation start of the compressor. A time detecting means for outputting a signal when a predetermined time has elapsed, a compressor controlling means for operating / stopping the compressor, an expansion valve controlling means for controlling an opening degree of the expansion valve, and the pipe temperature detecting means. A third control unit for controlling the compressor control unit and the expansion valve control unit based on signals from the operation mode detection unit and the time detection unit, wherein the third control unit When the cooling mode is detected by the mode detection means, the expansion valve is fully opened by the expansion valve control means, the operation of the compressor is started by the compressor control means, and then the operation of the compressor is started by the time detection means. A predetermined temperature difference is added to an entrance / exit temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means at the time when it is detected that a predetermined time has elapsed from the start of operation. The result is defined as a second reference temperature difference, and the second reference temperature difference is subtracted from an inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means during the subsequent operation of the compressor. The obtained result is regarded as a detected degree of superheat, and the expansion valve control means decreases the degree of opening of the expansion valve until the detected degree of superheat becomes greater than or equal to a first predetermined degree of superheat. The expansion valve control means obtains an opening that is larger than the opening of the expansion valve by a first predetermined opening at the time when the expansion valve reaches a predetermined opening, and sets the obtained opening to a subsequent opening of the expansion valve. And if the detected degree of superheat is greater than or equal to a second predetermined degree of superheat, which is smaller than the first degree of superheat, the expansion valve is set so as to increase the degree of opening of the expansion valve by a second predetermined degree of opening. Controlling the control means, and When the degree of heat is smaller than 0, the degree of opening of the expansion valve is set to the second degree.
The expansion valve control means is controlled to set the opening degree to be smaller by a predetermined opening degree, and the expansion valve control means is configured to maintain the opening degree of the expansion valve when the detected superheat degree is 0 or more and less than the second predetermined superheating degree. It controls the means.

With the above configuration, the opening degree of the expansion valve can be controlled so that the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger, which varies according to the cooling load in the room, is kept close to zero. However, it is possible to realize a control close to an ideal state in which the performance possessed by the heat exchanger can be maximized.

[0034] The invention according to claim 4 provides an outdoor unit comprising a compressor, an outdoor heat exchanger, an outdoor blower and an expansion valve, and an indoor unit comprising a refrigerant diverter, an indoor heat exchanger and an indoor blower. And the compressor, the outdoor heat exchanger, the expansion valve, the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in a loop with a refrigerant pipe to circulate a refrigerant. In the cycle, an indoor inlet pipe temperature sensor installed on a refrigerant pipe between the expansion valve and the refrigerant flow divider, an indoor outlet pipe temperature sensor installed on an outlet collective pipe of the indoor heat exchanger, and the indoor inlet pipe A temperature sensor, a pipe temperature detecting means for converting an output from the indoor outlet pipe temperature sensor into a temperature signal, an operation mode detecting means for detecting an operation mode of the cooling cycle, and an operation start of the compressor. A time detecting means for outputting a signal when a predetermined time has elapsed, a compressor controlling means for operating / stopping the compressor, an expansion valve controlling means for controlling an opening degree of the expansion valve, and the pipe temperature detecting means. A fourth control unit for controlling the compressor control unit and the expansion valve control unit based on signals from the operation mode detection unit and the time detection unit, wherein the fourth control unit When the cooling mode is detected by the mode detection means, the expansion valve is fully opened by the expansion valve control means, the operation of the compressor is started by the compressor control means, and then the operation of the compressor is started by the time detection means. An inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means at the time when it is detected that a predetermined time has elapsed from the start of operation is defined as a first reference temperature difference. The result obtained by subtracting the first reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means during the operation of the compressor is regarded as the detection superheat degree, The degree of opening of the expansion valve is reduced by the expansion valve control means until the degree of superheat is equal to or greater than a first predetermined degree of superheat, and the expansion at the time when the detected degree of superheat is equal to or greater than the first predetermined degree of superheat. An opening degree larger than the opening degree of the valve by a first predetermined opening degree is obtained, and the expansion valve control means is controlled so that the obtained opening degree becomes a subsequent opening degree of the expansion valve. When the compressor is started again after the cooling cycle is detected by the means and the compressor is changed from the operating state to the stopped state, the opening degree of the expansion valve is set to the stopped state. Just before The operation of the compressor is restarted by controlling the expansion valve control means so as to increase the opening degree of the expansion valve by a third predetermined opening degree, and the operation of the compressor is started by the time detection means. And a third reference temperature difference between the indoor inlet pipe temperature and the indoor outlet pipe temperature detected by the pipe temperature detecting means at the point in time when it is detected that a predetermined time has elapsed since the start of the operation of the compressor. The result obtained by subtracting the third reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means inside is a new detected superheat degree.

According to the above configuration, it is possible to cope with a change in the third reference temperature difference due to a change in the amount of refrigerant circulating in the cooling cycle due to a change in the indoor cooling load.

That is, when the compressor is restarted after the compressor has been changed from the operating state to the stopped state, the third predetermined opening is required for the opening degree of the expansion valve immediately before the compressor is stopped. Degree, the compressor is restarted, and the third reference temperature difference, which is the difference between the inlet / outlet temperature of the indoor inlet pipe temperature and the indoor outlet pipe temperature detected by the pipe temperature detecting means, is updated. The operation control corresponding to the cooling load fluctuation becomes possible.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heat pump type air conditioner according to the present invention will be described below with reference to the drawings. still,
The same components as those in the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Embodiment 1) FIG. 1 shows a refrigeration cycle diagram and a block diagram during a cooling operation of a heat pump type air conditioner according to Embodiment 1 of the present invention. In FIG. 1, a black arrow indicates the flow direction of the refrigerant during a normal cooling operation.

The heat pump type air conditioner of the present embodiment
It comprises an outdoor unit A and an indoor unit B.

The outdoor unit A comprises an outdoor heat exchanger 3 equipped with a compressor 1, an outdoor blower 4, and a pulse-type electric expansion valve EV. The indoor unit B has a refrigerant flow divider 5 and an indoor heat exchanger 7 And an indoor blower 8. The compressor 1, the outdoor heat exchanger 3, the pulse-type electric expansion valve EV, the refrigerant diverter 5, the indoor heat exchanger 7, and the compressor 1 are sequentially annularly connected by refrigerant piping. To form a cooling cycle for circulating the refrigerant.

A refrigerant pipe between the pulse-type electric expansion valve EV and the refrigerant flow divider 5 is provided with an indoor inlet pipe temperature sensor Th1.
And an indoor outlet pipe temperature sensor Th2 disposed in the outlet collecting pipe of the indoor heat exchanger 7, and outputs from the indoor inlet pipe temperature sensor Th1 and the indoor outlet pipe temperature sensor Th2 are converted into temperature signals by the pipe temperature detecting means Tsens. can do.

Further, a time detecting means TM for outputting a signal when a predetermined elapsed time has been reached, a compressor control means CMcnt for operating / stopping the compressor 1, and a pulse type electric expansion valve E
Expansion valve control means EVcnt for controlling the opening degree of V, and operation mode means Mod for detecting the operation mode of the cooling cycle
e.

Then, the first control means Cnt1 detects the cooling mode from the operation mode means Mode, and sets the expansion valve full opening degree ratio setting means 51 for setting the pulse type electric expansion valve EV to 100% corresponding to the full opening pls0; A reference temperature difference Δto1 calculation means 52 for calculating a first reference temperature difference Δto1 when an output signal when the elapsed time τ reaches a predetermined time Δτ is detected by the detection means TM; a reference temperature difference Δto1 calculation means 52; Detected superheat degree SH calculating means 53 for calculating detected superheat degree SH from pipe temperature detecting means Tsens, and predetermined superheat degree SH1 storage means 5 for storing first predetermined superheat degree SH1
4, a superheat degree comparing means 55 for comparing the magnitude relation between the detected superheat degree SH and the first predetermined superheat degree SH1, and an expansion valve lower limit opening ratio setting means for setting an opening degree equivalent to the expansion valve lower limit opening pls1. 56 and expansion valve opening ratio setting means 57 for setting an optimum expansion valve opening ratio. The compressor control is performed to optimally control the opening of the pulse type electric expansion valve EV during operation of the compressor 1. It operates the means CMcnt and the expansion valve control means EVcnt.

The operation of the heat pump type air conditioner configured as described above will be described below with reference to FIGS. 2 and 3. First, the characteristics of a refrigeration cycle of a general vapor compression heat pump will be described with reference to FIG. FIG.
Among the results of experiments performed by the present inventors using a general heat pump type air conditioner, the difference between the inlet / outlet temperature t2 between the indoor outlet pipe temperature t2 and the indoor inlet pipe temperature t1 during the cooling operation Δ
It is a graph which shows the characteristic with respect to the opening degree ratio of the pulse-type electric expansion valve EV of t, the indoor heat exchanger outlet superheat degree (= outlet refrigerant temperature-outlet refrigerant pressure saturation temperature), and the cooling capacity ratio.

In the design of a general refrigeration cycle, in order to expand the operation range, the pulse-type electric expansion valve EV is controlled to the opening amount at which the optimum refrigerant circulation amount is obtained, and to the optimum circulation amount considering the allowance. The opening can be set up to a large refrigerant circulation amount.

Therefore, the pulse type electric expansion valve EV is fully opened,
Alternatively, under the condition of a relatively large opening, the refrigerant circulating amount in the refrigeration cycle is operated at almost the maximum, so the degree of subcooling of the refrigerant at the outlet of the outdoor heat exchanger functioning as a condenser or the indoor functioning as an evaporator The degree of superheat at the outlet of the heat exchanger cannot be secured, and both the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7 are in a two-phase refrigerant state.

That is, the inlet pipe temperature t1 of the refrigerant distributor 5 and the outlet pipe temperature t2 of the indoor heat exchanger 7 indicate the refrigerant saturation temperature for each refrigerant pressure.

At this time, since the pulse type electric expansion valve EV is operated in the fully opened state, the amount of circulating refrigerant in the refrigeration cycle is almost maximum, and the inlet of the refrigerant distributor 5 and the indoor heat exchanger 7
Since both outlets are in a two-phase refrigerant state, the inlet pipe temperature t1 of the refrigerant distributor 5 and the outlet pipe temperature t2 of the indoor heat exchanger 7 indicate the refrigerant saturation temperature for each refrigerant pressure. Therefore,
At this time, the refrigerant saturation temperature difference (t1−t2 = −Δt) between the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7 corresponds to the pressure loss in the pipe.

This state is maintained until the capacity of the outdoor heat exchanger as the condenser and the capacity of the indoor heat exchanger as the evaporator are properly balanced with respect to the circulation amount of the compressor constituting the refrigeration cycle. Almost maintained.

Therefore, as shown in FIG. 2, the temperature difference Δt between the indoor outlet pipe temperature t2 and the indoor inlet pipe temperature t1 detected by the pipe temperature detecting means Tsens depends on the opening ratio of the pulse type electric expansion valve EV. As it becomes smaller from the fully opened state, it tends to gradually increase from a constant state where there is almost no change, and shows a characteristic of rapidly increasing as the opening degree ratio becomes smaller.

On the other hand, as shown in FIG. 2, the degree of superheat SH at the outlet of the indoor heat exchanger hardly changes when the opening ratio of the pulse type electric expansion valve EV is large, and is almost constant (SH = 0). , And shows a characteristic that when the opening ratio is made smaller than a certain opening ratio, it sharply rises.

At the same time, as for the cooling capacity Q, as shown in FIG. 2, the opening degree slightly larger than the opening degree ratio of the pulse-type electric expansion valve EV which ensures the superheat degree SH at the outlet of the indoor heat exchanger and rises sharply. In the ratio, the indoor heat exchanger 7 which is an evaporator
At the outlet of the refrigerant, the refrigerant becomes almost saturated vapor state (SH = 0), and the evaporation performance (cooling capacity ratio) becomes the maximum, that is, the refrigerant circulation amount and the performance of the indoor heat exchanger are almost in an optimally balanced state. This shows the characteristic that is a value.

Next, the flowchart of FIG. 3 shows the contents of the control during the cooling operation of the present embodiment in consideration of the above characteristics.

First, in step 1, the operation mode detecting means Mode detects that the cooling operation mode has been set, and in step 2, a compressor start signal is sent from the operation mode detecting means Mode to the expansion valve full opening ratio setting means 51. Output, the opening ratio of the pulse type electric expansion valve EV is fully opened pls0.
In step 3, a compressor start signal is output to the compressor control means CMcnt, and the
Start

Thereafter, the elapsed time τ after the start of the compressor 1 is detected by the time detecting means TM in step 4, and
At 5, the time detecting means TM compares whether the elapsed time τ after the start of the compressor 1 has reached the predetermined time Δτ, and if the elapsed time τ <the predetermined time Δτ, repeats the routine returning to step 4. If ≧ predetermined time Δτ, the process proceeds to step 6.

In step 6, the pipe temperature detecting means Tsen
s to pipe temperature detection means Tsens to reference temperature difference Δto
The signals of the indoor inlet pipe temperature t1 and the indoor outlet pipe temperature t2 are output to the first detecting means 52, converted into temperature signals by the reference temperature difference Δto1 detecting means 52, and the inlet / outlet temperature difference Δt (= t2- t1) is the first reference temperature difference Δto
Calculated as 1.

Next, in step 7, the detected superheat degree SH calculating means 53 calculates the difference Δt (= t2−t1) between the inlet and outlet pipe temperature t1 and the indoor inlet pipe temperature t2 detected by the pipe temperature detecting means Tsens. Considering the first reference temperature difference Δto1 corresponding to the negative number of the pressure loss in the pipe between the inlet of the refrigerant flow divider 5 and the outlet of the indoor heat exchanger 7, that is, subtracting the first reference temperature difference Δto1 (Δt−Δto1) do it,
The detected superheat degree SH is calculated by subtracting the influence of the pressure loss in the pipe between the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7.

The characteristics of the detected superheat SH with respect to the opening ratio of the pulse type electric expansion valve EV show the same tendency as the characteristics of the refrigerant superheat at the outlet of the indoor heat exchanger as shown in the graph of FIG.

Therefore, in step 8, the superheat degree comparing means 5
5, the magnitude of the detected superheat SH is compared with the first predetermined superheat SH1 stored in the predetermined superheat SH1 storage means 54, and the detected superheat SH is determined to be the first predetermined superheat SH1.
If it is smaller (SH <SH1), the opening degree ratio of the pulse-type electric expansion valve EV is further reduced by a predetermined opening degree in step 9, and then the process returns to step 7, and the detected superheat degree S again.
Calculate H.

In step 8, when the detected superheat degree SH is larger than the first predetermined superheat degree SH1 (SH ≧ SH1), the process proceeds to step 10.

Further, in step 10, the expansion valve lower limit opening ratio setting means 56 lowers the opening ratio of the pulse type electric expansion valve EV when the detected superheat SH becomes equal to or higher than the first predetermined superheat SH1. Degree pls1 and step1
In step 1, the expansion valve opening ratio setting means 57 adds the set opening ratio of the pulse-type electric expansion valve EV inversely to the lower opening pls1 by the first predetermined opening Δpls1 (pls1).
+ Δpls1) The opening degree is set to an opening degree equivalent to the opening degree pls2, and the operation of the compressor 1 is continued.

Therefore, as long as the indoor cooling load does not fluctuate significantly thereafter, the refrigerant superheat degree at the outlet of the indoor heat exchanger 7 is not excessively secured, and the refrigerant is in a saturated steam state, that is, a state where the superheat degree is almost zero. The operation will be continued.

As described above, in the heat pump type air conditioner of the present embodiment, the cooling mode is detected by the operation mode means Mode, the time signal from the time detecting means TM, and the indoor inlet pipe detected by the pipe temperature detecting means Tsens. The temperature signals of the temperature t1 and the indoor outlet pipe temperature t2 are taken in,
First control means C for controlling the compressor control means CMcnt and the expansion valve control means EVcnt so as to optimally control the opening ratio of the pulse type electric expansion valve EV during the operation of the compressor 1.
Because of the provision of nt1, the following effects are exhibited.

First, within a predetermined time Δτ after the start of the compressor 1, the pulse-type electric expansion valve EV is operated with the valve fully opened.
Since the refrigerant circulation amount in the refrigeration cycle is almost maximum, and the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7 are both in a two-phase refrigerant state, the pipe temperature of the inlet of the refrigerant distributor 5 and the indoor heat exchanger 7 The outlet pipe temperature indicates the refrigerant saturation temperature for each refrigerant capacity.

Accordingly, the refrigerant saturation temperature difference between the inlet of the refrigerant flow divider 5 and the outlet of the indoor heat exchanger 7 corresponds to the pressure loss in the pipe, and its negative number is detected as the first reference temperature difference Δto1,
By subtracting the first reference temperature difference Δto1 from the inlet / outlet temperature difference Δt between the indoor outlet pipe temperature t2 and the indoor inlet pipe temperature t1 after the lapse of the predetermined time Δτ, the refrigerant flow divider 5
The net superheat degree SH at the outlet of the indoor heat exchanger 7 excluding the influence of the pressure loss in the pipe between the inlet and the outlet of the indoor heat exchanger 7 can be detected only from the temperature difference.

Further, by using the characteristics of the detected superheat degree SH, the refrigerant superheat degree at the outlet of the indoor heat exchanger 7 functioning as an evaporator is not excessively secured, and the saturated steam state, that is, almost Since it is possible to approach the state of degree = 0, it is possible to realize control close to an ideal state, in which the performance possessed by the heat exchanger can be exhibited almost to the maximum.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to the drawings. The same components as in Embodiment 1 will be assigned the same reference numerals and detailed description thereof will be omitted.

FIG. 5 shows a refrigeration cycle diagram and a block diagram during the cooling operation of the heat pump type air conditioner according to the second embodiment of the present invention. In FIG. 5, black arrows indicate the flow direction of the refrigerant during normal cooling operation. The heat pump air conditioner of the present embodiment has an outdoor unit A similar to the first embodiment.
And an indoor unit B. However, in the present embodiment, instead of the first control means Cnt1 of the first embodiment,
A second control unit Cnt2 is provided.

The second control means Cnt2 is the operation mode means M
mode, the cooling mode is detected, and the pulse type electric expansion valve E is detected.
The second reference temperature is set when an output signal when the elapsed time τ reaches the predetermined time Δτ is detected from the expansion valve full opening degree ratio setting means 51 for setting V to 100% corresponding to the full opening pls0 and the time detecting means TM. Reference temperature difference Δto for calculating difference Δto2
2 calculating means 62 and reference temperature difference Δto2 calculating means 62,
And a detected superheat degree SH calculating means 53 for calculating the detected superheat degree SH from the pipe temperature detecting means Tsens, a predetermined superheat degree SH1 storage means 54 for storing the first predetermined superheat degree SH1, a detected superheat degree SH and a first predetermined superheat. A superheat degree comparing means 55 for comparing a magnitude relationship with the degree SH1, and an expansion valve lower limit opening degree pls1.
Expansion valve lower limit opening ratio setting means 56 for setting a considerable opening ratio
And an expansion valve opening ratio setting means 57 for setting an optimum expansion valve opening ratio.

The second control means Cnt2 detects the cooling mode by the operation mode means Mode, starts the compressor 1 by fully opening the pulse type electric expansion valve EV, and sets the elapsed time τ to the predetermined time by the time detection means TM. When it is detected that Δτ has been reached, the indoor inlet pipe temperature t1 and the indoor outlet pipe temperature t2 detected by the pipe temperature detecting means Tsens.
The result obtained by adding the predetermined temperature difference θ to the inlet / outlet temperature difference Δt as the second reference temperature difference Δto2, and the indoor / outlet pipe temperature t1 detected by the pipe temperature detecting means Tsens during the subsequent continuation of the operation of the compressor 1. Indoor inlet pipe temperature t
The result obtained by subtracting the second reference temperature difference Δto2 from the entrance / exit temperature difference Δt (= t2−t1) from the second reference temperature is defined as a detected superheat degree SH,
The opening ratio of the pulse-type electric expansion valve EV is reduced until the detected superheat SH becomes equal to or more than the first predetermined superheat SH1, and the pulse when the detected superheat SH becomes equal to or more than the first predetermined superheat SH1. In contrast, the opening ratio is set to be larger than the opening ratio of the electric expansion valve EV by the amount corresponding to the first predetermined opening Δpls1.

The operation of the heat pump type air conditioner configured as described above will be described below with reference to FIGS. 6 and 7. First, the characteristics of the refrigeration cycle of a general vapor compression heat pump will be described with reference to FIG. FIG.
The characteristics of the inlet-outlet temperature difference Δt between the indoor outlet pipe temperature t2 and the indoor inlet pipe temperature t1 during the cooling operation, the indoor heat exchanger outlet superheat degree SH, and the cooling capacity ratio with respect to the opening degree ratio of the pulsed electric expansion valve EV are shown. It is a graph shown.

In the design of a general refrigeration cycle, in order to expand the operating range, the pulse-type motor-operated expansion valve EV needs to have an optimal refrigerant circulation amount with respect to the opening degree at which the optimal refrigerant circulation amount can be obtained. The opening can be set up to a large refrigerant circulation amount.

Therefore, the pulse type electric expansion valve EV is fully opened,
Alternatively, under the condition of a relatively large opening, the refrigerant circulating amount in the refrigeration cycle is operated at almost the maximum, so the degree of subcooling of the refrigerant at the outlet of the outdoor heat exchanger functioning as a condenser or the indoor functioning as an evaporator The degree of superheat at the outlet of the heat exchanger cannot be secured, and both the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7 are in a two-phase refrigerant state.

That is, the inlet pipe temperature t1 of the refrigerant distributor 5 and the outlet pipe temperature t2 of the indoor heat exchanger 7 indicate the refrigerant saturation temperature for each refrigerant pressure.

At this time, since the pulse-type electric expansion valve EV is operated in the fully opened state, the amount of circulating refrigerant in the refrigeration cycle is almost maximum, and the inlet of the refrigerant distributor 5 and the indoor heat exchanger 7
Since both outlets are in a two-phase refrigerant state, the inlet pipe temperature t1 of the refrigerant distributor 5 and the outlet pipe temperature t2 of the indoor heat exchanger 7 indicate the refrigerant saturation temperature for each refrigerant pressure. Therefore,
At this time, the refrigerant saturation temperature difference (t1−t2 = −Δt) between the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7 corresponds to the pressure loss in the pipe.

This state is maintained until the capacity of the outdoor heat exchanger as the condenser and the capacity of the indoor heat exchanger as the evaporator are properly balanced with respect to the circulation amount of the compressor constituting the refrigeration cycle. Almost maintained.

Therefore, as shown in FIG. 6, the temperature difference Δt between the indoor outlet pipe temperature t2 and the indoor inlet pipe temperature t1 detected by the pipe temperature detecting means Tsens is determined by the ratio of the opening degree of the pulse type electric expansion valve EV. As it becomes smaller from the fully opened state, it tends to gradually increase from a constant state where there is almost no change, and shows a characteristic of rapidly increasing as the opening degree ratio becomes smaller.

At this time, the inlet / outlet temperature difference Δt immediately before the inlet / outlet temperature difference Δt sharply rises is determined by the pulse type electric expansion valve EV.
Rises by the temperature difference θ with respect to the fully opened state.

This is because the refrigerant circulation amount in the refrigeration cycle gradually decreases as the opening ratio of the pulse type electric expansion valve EV decreases, so that the inlet of the refrigerant distributor 5 and the indoor heat exchanger 7 This is because the refrigerant saturation temperature difference (t1−t2 = −Δt) corresponding to the pressure loss in the pipe between the outlet and the outlet gradually decreases, though slightly.

On the other hand, as shown in FIG. 6, the degree of superheat SH at the outlet of the indoor heat exchanger hardly changes when the opening ratio of the pulse type electric expansion valve EV is large, and is almost constant (SH = 0). , And shows a characteristic that when the opening ratio is made smaller than a certain opening ratio, it sharply rises.

At the same time, as for the cooling capacity Q, as shown in FIG. 6, the opening degree slightly larger than the opening ratio of the pulse-type electric expansion valve EV, which has the degree of superheat SH at the outlet of the indoor heat exchanger and increases rapidly, is secured. In the ratio, the indoor heat exchanger 7 which is an evaporator
At the outlet of the refrigerant, the refrigerant becomes almost saturated vapor state (SH = 0), and the evaporation performance (cooling capacity ratio) becomes the maximum, that is, the refrigerant circulation amount and the performance of the indoor heat exchanger are almost in an optimally balanced state. This shows the characteristic that is a value.

Next, FIG. 7 is a flowchart showing the contents of control during the cooling operation of the present embodiment in consideration of the above characteristics.

First, in step 1, the operation mode detecting means Mode detects that the cooling operation mode has been set, and in step 2, a compressor start signal is sent from the operation mode detecting means Mode to the expansion valve full opening ratio setting means 51. Output, the opening ratio of the pulse type electric expansion valve EV is fully opened pls0.
The opening ratio is set to 100%, and a compressor start signal is output to the compressor control means CMcnt in step 3 to start the compressor 1.

Thereafter, the time detecting means TM detects the compressor 1 start signal in step 4 and compares in step 5 whether the elapsed time τ after starting the compressor 1 has reached the predetermined time Δτ by the time detecting means TM. If the elapsed time τ <the predetermined time Δτ, the routine of returning to step 4 is repeated, and if the elapsed time τ ≧ the predetermined time Δτ, step 6
Proceed to.

In step 6, the pipe temperature detecting means Tsen
The signal of the indoor inlet pipe temperature t1 and the indoor outlet pipe temperature t2 is output from the s to the reference temperature difference Δto2 detecting means, converted into a temperature signal by the reference temperature difference Δto2 detecting means 62, and the inlet / outlet temperature difference Δt at this time is output. (= T2-t1) and the result of adding the predetermined temperature difference θ to the second reference temperature difference Δ
It is calculated as to2.

Next, at step 7, the detected superheat degree SH calculating means 53 calculates the entrance / exit of the indoor outlet pipe temperature t2 and the indoor inlet pipe temperature t1 detected by the pipe temperature detecting means Tsens after the lapse of the predetermined time Δτ. Considering the temperature difference Δt (= t2−t1), a second reference temperature difference Δto2 corresponding to the pressure loss in the pipe between the inlet of the refrigerant flow divider 5 and the outlet of the indoor heat exchanger 7, that is, the second reference temperature difference Δt
o2 is subtracted ([Delta] t- [Delta] to2), and the detected superheat degree SH is calculated by subtracting the influence of the pressure loss in the pipe between the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7.

Then, at step 8, the superheat degree comparing means 5
5, the magnitude relationship between the detected superheat degree SH and the first predetermined superheat degree SH1 is compared, and the detected superheat degree SH is set to the first predetermined superheat degree S1.
If it is smaller than H1 (SH <SH1), the opening degree ratio of the pulse-type electric expansion valve EV is further reduced by a predetermined opening degree in step 9, and the process returns to step 7 to calculate the detected superheat degree SH again.

In step 8, when the detected superheat degree SH is larger than the first predetermined superheat degree SH1 (SH ≧ SH1), the process proceeds to step 10.

Further, at step 10, the expansion valve lower limit opening ratio setting means 56 lowers the opening ratio of the pulse type electric expansion valve EV when the detected superheat SH becomes equal to or higher than the first predetermined superheat SH1. Degree pls1 and step1
At 1, the expansion valve opening ratio setting means 57 reversely adds the set opening ratio of the pulse type electric expansion valve EV by the first predetermined opening Δpls1 corresponding to the lower limit opening pls1 (pls1 +
An opening ratio corresponding to pls2 obtained by Δpls1) is set, and the operation of the compressor 1 is continued.

Therefore, unless the indoor cooling load fluctuates thereafter, the refrigerant superheat degree at the outlet of the indoor heat exchanger 7 is not excessively secured, and the refrigerant is in a saturated steam state, that is, a state in which the superheat degree is almost zero. The operation will be continued.

As described above, in the heat pump type air conditioner of the present embodiment, the cooling mode is detected by the operation mode means Mode, the time signal from the time detection means TM, and the indoor inlet pipe detected by the pipe temperature detection means Tsens. The temperature signals of the temperature t1 and the indoor outlet pipe temperature t2 are taken in,
Second control means C for controlling the compressor control means CMcnt and the expansion valve control means EVcnt so as to optimally control the opening ratio of the pulse type electric expansion valve EV during operation of the compressor 1.
Because of the provision of nt2, the following effects are exhibited.

That is, the inlet of the refrigerant distributor 5 and the indoor heat exchanger 7
It is possible to correct the difference that occurs in the saturation temperature difference of the refrigerant corresponding to the pipe pressure loss between the outlet and the outlet. That is, the difference between the saturation temperature difference after the elapse of the predetermined time Δτ of the start of the compressor 1 and the saturation temperature difference at the time when the opening ratio of the pulsed electric expansion valve EV is reduced after the elapse of the predetermined time Δτ,
That is, by considering the predetermined temperature difference θ in the second reference temperature difference Δto2, it is possible to accurately detect the detected superheat degree SH at the outlet of the indoor heat exchanger 7.

Further, by using the characteristic of the detected superheat degree SH, the refrigerant superheat degree at the outlet of the indoor heat exchanger 7 functioning as an evaporator is not excessively secured, and the saturated steam state, that is, almost Since it is possible to approach the state of degree = 0, it is possible to realize control close to an ideal state, in which the performance possessed by the heat exchanger can be maximized.

(Embodiment 3) Next, Embodiment 3 of the present invention will be described with reference to the drawings. The same components as in Embodiment 2 will be assigned the same reference numerals and detailed description thereof will be omitted.

FIG. 8 shows a refrigeration cycle diagram and a block diagram during a cooling operation of the heat pump type air conditioner according to Embodiment 3 of the present invention. The heat pump type air conditioner of this embodiment includes an outdoor unit A and an indoor unit B as in the second embodiment. However, in the present embodiment, a third control means Cnt3 is provided instead of the second control means Cnt2 of the second embodiment.

The third control means Cnt3 is connected to the second control means Cn.
In addition to t2, the degree of superheat comparing the detected superheat degree SH obtained by the detected superheat degree SH calculating means 53 with the second predetermined superheat degree SH2 stored in the predetermined superheat degree SH2 storage means 64 is compared. 2 comparing means 66, the detected superheat SH and 0
The third superheat degree comparison means 76, the second superheat degree comparison means 66, and the third superheat degree comparison means 76, which compare the magnitude relation with pls2 + Δpls2, pls
Expansion valve opening ratio setting means 58, 59, and 60 for setting each opening ratio corresponding to 2-Δpls2 and the current opening.

Then, in addition to the operation of the second control means Cnt2, the third control means Cnt3 adds the opening ratio of the pulse-type electric expansion valve EV when the detected superheat SH becomes equal to or higher than the first predetermined superheat SH1. Is the first predetermined opening degree Δ with respect to pls1.
The opening pls2 (= pls1 +
Δpls1), the second predetermined superheat SH2 in which the detected superheat SH is smaller than the first predetermined superheat SH1.
If the detected superheat SH is smaller than 0, the opening ratio of the pulse-type electric expansion valve EV is set to the second predetermined opening Δpls2. The opening degree is set to be smaller by the predetermined opening degree Δpls2, the detected superheating degree SH is 0 or more, and the second predetermined superheating degree SH
In the case of 2 or less, the expansion valve control means EV is operated so as to maintain the opening ratio of the pulse type electric expansion valve EV.

The operation of the heat pump type air conditioner configured as described above will be described below with reference to FIG. FIG. 9 is a flowchart of the control contents during the cooling operation of the present embodiment. Step 1 to step 11 are the same as those in the second embodiment, and thus detailed description is omitted.

However, step 10 and step 10 in the first embodiment are performed.
11 is related in the third embodiment, and will be described again.

First, at step 10, the expansion valve lower limit opening ratio setting means 56 lowers the opening ratio of the pulse type electric expansion valve EV when the detected superheat SH becomes equal to or higher than the first predetermined superheat SH1. Degree pls1 and step1
In step 1, the expansion valve opening ratio setting means 57 reversely adds the set opening ratio of the pulse type electric expansion valve EV by a first predetermined opening Δpls1 to the equivalent of the lower limit opening pls1 (pls1 + Δ
(pls1) The opening ratio corresponding to the opening pls2 is set, and the operation of the compressor 1 is continued.

Next, at step 12, the superheat degree second comparing means 66 compares the magnitude relation between the detected superheat degree SH and the first predetermined superheat degree SH2 stored in the predetermined superheat degree SH2 storage means 64, Performs control branch. That is, when the detected superheat degree SH is larger than a second predetermined superheat degree SH2 (for example, 1K) smaller than the first predetermined superheat degree SH1 (for example, 4K), the process branches to step 14, and the detected superheat degree SH is set at step 13. Compare the magnitude relationship with 0 and detect the degree of superheat SH
Is smaller than 0, the flow branches to step 15, and if the detected superheat degree SH is 0 or more and smaller than the second predetermined superheat degree SH2, the flow branches to step 16.

That is, in step 14, the detected superheat SH is changed to the second predetermined superheat SH by the expansion valve opening ratio setting means 58.
In the case of more than 2 (SH ≧ 1K), the opening ratio of the pulse-type electric expansion valve EV is set to be larger by the second predetermined opening Δpls2, and in step 15, the detected superheat degree is detected by the expansion valve opening ratio setting means 59. When SH is smaller than 0 (SH <0
K) sets the opening ratio of the pulse-type electric expansion valve EV to be smaller by the second predetermined opening Δpls2, and further detects the superheat degree SH of 0 or more by the expansion valve opening ratio setting means 60 in step 16; 2 When the superheat degree is less than the predetermined superheat degree SH2 (0 ≦ S
H <1) operates the expansion valve control means EV so as to maintain the opening ratio of the pulse type electric expansion valve EV.

Here, the detected superheat degree SH has a predetermined temperature difference θ.
Is added, the lower limit of the detected superheat degree SH is −θ.
To exist.

As a result, the detected superheat degree SH at the outlet of the indoor heat exchanger 7 that changes according to the indoor cooling load is changed from 0 to the second degree.
Since the opening ratio of the pulse type electric expansion valve EV can be controlled so as to fall within the predetermined superheat degree SH2, the performance possessed by the indoor heat exchanger 7 is maximized even when the cooling load fluctuates. Control that is close to the ideal state can be realized.

As described above, the heat pump type air conditioner of the present embodiment has a configuration in which the third control means Cnt3 is provided instead of the second control means Cnt2 of the second embodiment, that is, the second control means. In addition to the operation of the means Cnt2, the opening ratio of the pulse-type electric expansion valve EV at the time when the detected superheat SH becomes equal to or more than the first predetermined superheat SH1 is equivalent to pls1 equivalent to the first predetermined opening Δpls. Conversely, if the detected degree of superheat SH is equal to or greater than the second predetermined superheat SH2, which is smaller than the first predetermined superheat SH1, after the degree of opening pls2 (= pls1 + Δpls1) is set to be larger, the pulse-type electric expansion valve EV is opened. The degree ratio is set to be larger by the second predetermined opening degree Δpls2, and when the detected superheat degree SH is smaller than 0, the opening degree ratio of the pulse type electric expansion valve EV is set to be smaller by the second predetermined opening degree Δpls2, Knowledge superheat degree SH is 0 or more and in the case of the second lower than the predetermined superheat degree SH2 pulsed electric expansion valve E
Since the expansion valve control means EV is operated so as to maintain the opening degree ratio of V, the following effects are exhibited.

That is, in addition to the effect of the second embodiment, the pulse is set so that the detected superheat degree SH at the outlet of the indoor heat exchanger 7 that changes according to the indoor refrigerant load falls between 0 and the second predetermined superheat degree SH2. Since the opening ratio of the electric motor-operated expansion valve EV can be controlled, even if the cooling load fluctuates, the performance possessed by the indoor heat exchanger 7 can be maximized, and control close to an ideal state is realized. It becomes possible.

(Embodiment 4) Next, Embodiment 4 of the present invention will be described with reference to the drawings. The same components as those in Embodiment 1 will be assigned the same reference numerals and detailed description thereof will be omitted.

FIG. 10 shows a refrigeration cycle diagram and a block diagram of a heat pump type air conditioner according to Embodiment 4 of the present invention during a cooling operation. The heat pump type air conditioner of this embodiment includes an outdoor unit A and an indoor unit B as in the first embodiment. However, in the present embodiment, a fourth control unit Cnt4 is provided instead of the first control unit Cnt1 of the first embodiment.

The fourth control means Cnt4 includes the first control means C
opening ratio storage means 71 for storing the opening ratio of the pulse type electric expansion valve EV in addition to nt1, and an operation mode detecting means M
The restart signal from the compressor 1 is detected from the compressor 1 and the compressor 1
An expansion valve opening ratio setting means 61 for setting an opening ratio of the pulse type electric expansion valve EV at the time of startup is provided.

Then, in the fourth control means Cnt4, the first
In addition to the operation of the control means Cnt1, the operation mode means Mo
de when the cooling cycle is being detected, and after the compressor 1 is changed from the operating state to the stopped state, and the compressor 1 is started again, the opening degree of the pulse type electric expansion valve EV is set to The operation of the compressor 1 is restarted by operating the expansion valve control means EVcnt so that the opening degree of the pulse-type electric expansion valve EV is set to be larger than the opening degree of the pulse type electric expansion valve EV immediately before the stop state of the compressor 1 by the third predetermined opening Δpls3. When the time detecting means TM detects that the elapsed time τ has reached the predetermined time Δτ, an inlet / outlet temperature difference Δt (= t2) between the indoor inlet pipe temperature t1 and the indoor outlet pipe temperature t2 detected by the pipe temperature detecting means Tsens. −t1) is set as the third reference temperature difference Δto3, and a control operation for updating the first reference temperature difference Δto1 is performed.

The operation of the heat pump type air conditioner configured as described above will be described below with reference to FIG. FIG. 11 is a flowchart of control contents during the cooling operation according to the present embodiment. Step 1 to step 11 are the same as those in the first embodiment, and a detailed description thereof will be omitted.

However, step 9 and step 1 in the first embodiment are performed.
1 is also relevant in the fourth embodiment, and will be described again.

First, at step 10, the expansion valve lower limit opening ratio setting means 56 lowers the opening ratio of the pulse type electric expansion valve EV when the detected superheat SH exceeds the first predetermined superheat SH1. Degree pls1 and step1
At 1, the opening ratio of the pulse type electric expansion valve EV is set to the lower limit opening pl.
An opening ratio corresponding to pls2 obtained by adding (pls1 + Δpls1) in reverse to the first predetermined opening Δpls1 with respect to s1 is set, and the operation of the compressor 1 is continued.

Thereafter, in step 17, when the indoor temperature reaches the set temperature, or when the refrigeration cycle is in an abnormal operation state and the protection control is operated in the refrigeration cycle, the compressor 1 is stopped from the operation state. become. In this case, the opening pls2 of the pulse-type electric expansion valve EV immediately before the compressor 1 is stopped is stored in the opening ratio storage means 71 provided in the expansion valve opening ratio setting means 57.

Next, at step 18, it is monitored whether the compressor 1 is restarted. That is, if the compressor 1 is restarted in step 18, the process proceeds to step 19; otherwise, the process is in a standby state of restarting the compressor 1 in step 17.

In step 19, a compressor restart signal is output from the operation mode setting means Mode to the expansion valve opening ratio setting means 61, and the expansion valve opening ratio setting means 61 opens the pulse type electric expansion valve EV. The degree of opening of the pulse-type electric expansion valve EV immediately before the compressor 1 is stopped is pl.
s2 is set to be larger by the third predetermined opening degree Δpls3, and then the expansion valve control means EVcnt is set to (pl
s2 + Δpls3) is output and operated.

Then, at step 20, a restart signal of the compressor 1 is output from the operation mode setting means Mode to the compressor control means CMcnt, and at step 21, the compressor start signal is received from the compressor control means CMcnt, The time detecting means TM starts counting the elapsed time τ after the machine 1 is started, and in step 22, the time detecting means TM compares whether the elapsed time τ has reached the predetermined time Δτ. In some cases, the routine of returning to step 21 is repeated, and if the elapsed time τ ≧ the predetermined time Δτ, the flow proceeds to step 23.

In step 23, the pipe temperature detecting means Tse
ns to the reference temperature difference calculation means 52
1, and a signal of the indoor outlet pipe temperature t2 is output and converted into a temperature signal by the reference temperature difference calculating means 52, and the inlet / outlet temperature difference Δt (= t2−t1) at this time is set as a third reference temperature difference Δto3. It calculates and updates the value from the first reference temperature difference Δto1.

At this time, although the pulse type electric expansion valve EV is not fully opened, the amount of circulating refrigerant in the refrigeration cycle is relatively large, and both the inlet of the refrigerant distributor 5 and the outlet of the indoor heat exchanger 7 are in a two-phase refrigerant state. Therefore, similarly to the case of the first embodiment, the inlet pipe temperature t1 of the refrigerant distributor 5 and the outlet pipe temperature t2 of the indoor heat exchanger 7 indicate the refrigerant saturation state for each refrigerant pressure. Therefore, the refrigerant saturation temperature difference between the inlet of the refrigerant flow divider 5 and the outlet of the indoor heat exchanger 7 (t1−t2 = −Δt)
o) corresponds to the pressure loss in the pipe.

Therefore, the degree of superheat SH detected in step 24 is
The calculating means 53 calculates the difference between the entrance / exit temperature difference Δt (= t2−t1) between the indoor outlet pipe temperature t2 and the indoor inlet pipe temperature t1 detected by the pipe temperature detecting means Tsens after the lapse of the predetermined time Δτ by the pulse method. Electric expansion valve E
The third reference temperature difference Δto3 corresponding to the pressure loss in the pipe between the V outlet and the outlet of the indoor heat exchanger 7 is taken into account, that is, the third reference temperature difference Δto3 is considered.
By subtracting the reference temperature difference Δto3 (Δt−Δto3), it is possible to calculate the detected superheat degree SH in which the influence of the pressure loss in the pipe between the inlet of the refrigerant flow divider 5 and the outlet of the indoor heat exchanger 7 is subtracted.

Thereafter, the control is repeated as a routine for returning to step 8 of the first embodiment. However, when returning to step 8 of the first embodiment, when
When the process proceeds to step 7, step 7 is replaced with step 24.

As described above, the heat pump type air conditioner of this embodiment has a configuration in which the fourth control means Cnt4 is provided instead of the first control means Cnt1 of the first embodiment, that is, the operation mode means When the compressor 1 is restarted after the cooling cycle is detected in the mode and the compressor 1 is changed from the operating state to the stopped state, the opening degree of the pulse-type electric expansion valve EV is set to the compressor. The operation of the compressor 1 is restarted by operating the expansion valve control means EVcnt so that the opening degree of the pulse-type electric expansion valve EV is set to be larger than the opening degree of the pulse type electric expansion valve EV immediately before the stop state of the compressor 1 by the third predetermined opening Δpls3. The elapsed time τ is determined by the time detecting means TM to be a predetermined time Δ
The temperature difference Δt (= t2−t1) between the indoor inlet pipe temperature t1 and the indoor outlet pipe temperature t2 detected by the pipe temperature detecting means Tsens when τ is reached is calculated as a third reference temperature difference Δt.
Since the control for updating the first reference temperature difference Δto1 is provided as o3, the following effects are exhibited.

That is, in addition to the effects of the first embodiment, it is possible to cope with a change in the refrigerant circulation amount in the cooling cycle due to a change in the indoor cooling load by grasping the change in the reference temperature difference.

That is, even when the compressor is restarted after the compressor is changed from the operating state to the stopped state, the third predetermined opening degree relative to the opening degree of the expansion valve immediately before the compressor stops. The compressor 1 is restarted by setting it larger by Δpls3, and a reference temperature difference Δt between the indoor inlet pipe temperature t1 and the indoor outlet pipe temperature t2 detected by the pipe temperature detecting means Tsens is defined as a first reference temperature difference. By updating from Δto1 to the third reference temperature difference Δto3, it becomes possible to perform operation control corresponding to a change in indoor cooling load.

In the first to fourth embodiments, the pulse-type electric expansion valve EV is installed upstream of the refrigerant flow divider 5 of the indoor unit B, but the outdoor heat exchange in the outdoor unit A is performed. Even in the case of the configuration installed on the downstream side of the heat exchanger 3, the same effect can be obtained in maximizing the performance of the indoor heat exchanger 7.

[0126]

As described above, the first aspect of the present invention provides an outdoor unit including a compressor, an outdoor heat exchanger, an outdoor blower, and an expansion valve, a refrigerant distributor, an indoor heat exchanger, and an indoor blower. And the compressor, the outdoor heat exchanger, the expansion valve, the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in a ring through a refrigerant pipe to form a refrigerant. In the cooling cycle that circulates, at the start of the operation of the compressor in the cooling mode, the expansion valve is fully opened, and then the indoor outlet pipe temperature and the indoor inlet pipe at the time when a predetermined time has elapsed since the start of the compressor operation. The difference between the inlet / outlet temperature and the temperature is defined as a first reference temperature difference, and the result obtained by subtracting the first reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature during the continuation of the operation of the compressor thereafter. As the perceived degree of superheat, the degree of opening of the expansion valve is reduced until the detected degree of superheat becomes equal to or greater than a first predetermined degree of superheat, and the detected degree of superheat becomes equal to or greater than the first degree of superheat. An opening larger than the opening of the expansion valve by a first predetermined opening is obtained, and the obtained opening is used as the opening of the expansion valve thereafter.

Thus, it is possible to detect the net degree of superheat at the outlet of the indoor heat exchanger by subtracting the influence of the pressure loss in the pipe between the inlet of the refrigerant distributor and the outlet of the indoor heat exchanger. In addition, the refrigerant superheat degree at the outlet of the indoor heat exchanger functioning as an evaporator is not largely secured, and it is possible to approach a saturated vapor state, that is, a state where the superheat degree is almost zero. That the performance possessed can be maximized,
Control close to the ideal state can be realized.

Further, the invention according to claim 2 is the invention according to claim 1, wherein the difference between the inlet / outlet temperature of the indoor outlet pipe and the temperature of the inlet / outlet pipe at the time when a predetermined time has elapsed since the start of the operation of the compressor. The temperature difference is replaced by a reference temperature difference obtained by adding a predetermined temperature difference to an entrance / exit temperature difference between an indoor outlet pipe temperature and an indoor inlet pipe temperature.

This makes it possible to correct the difference in the saturation temperature difference of the refrigerant corresponding to the pipe pressure loss between the inlet of the refrigerant distributor and the outlet of the indoor heat exchanger.

That is, the difference between the saturation temperature difference after the elapse of the predetermined time of starting the compressor and the saturation temperature difference at the time when the opening degree of the expansion valve is reduced after the elapse of the predetermined time is determined by the second temperature.
By adding to the reference temperature difference, the degree of superheat detected at the outlet of the indoor heat exchanger can be accurately detected.

Further, according to the invention of claim 3, in addition to the invention of claim 2, after the opening degree of the expansion valve is set, the detected superheat degree is equal to or higher than a second predetermined superheat degree which is smaller than the first predetermined superheat degree. In some cases, the opening of the expansion valve is set to be larger by a second predetermined opening, and when the detected superheat is smaller than 0, the opening of the expansion valve is set to be smaller by the second predetermined opening. It was done.

Thus, the opening degree of the expansion valve can be controlled so that the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger, which varies according to the cooling load in the room, is kept close to zero, so that even if the cooling load fluctuates. In addition, it is possible to realize a control close to an ideal state, in which the performance possessed by the heat exchanger can be maximized.

[0133] In addition to the first aspect of the present invention, when the compressor is temporarily stopped and restarted in the cooling cycle after the opening degree of the expansion valve is set, the expansion valve may be used. The opening is set to be larger by a third predetermined opening than the opening of the expansion valve immediately before the compressor is stopped, and the operation of the compressor is restarted. The inlet / outlet temperature difference between the indoor inlet pipe temperature and the indoor outlet pipe temperature at the point in time when the predetermined time has elapsed is defined as a third reference temperature difference. The result obtained by subtracting the third reference temperature difference from the entrance / exit temperature difference is used as a new detected superheat degree.

Thus, it is possible to cope with a change in the third reference temperature difference caused by a change in the indoor cooling load and a change in the amount of refrigerant circulating in the cooling cycle.

That is, after the compressor has been stopped from the operating state due to, for example, the case where the indoor temperature has reached the set temperature or the case where the refrigeration cycle is in an abnormal operation state and the protection control is operated in the refrigeration cycle. When the operation of the compressor is started again, the opening degree of the expansion valve immediately before the stop of the compressor is set to be larger by a third predetermined opening degree, the compressor is restarted, and the pipe temperature detecting means By updating the third reference temperature difference, which is the difference between the inlet / outlet pipe temperature and the indoor / outlet pipe temperature detected by the above, the operation control corresponding to the change in the indoor cooling load becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of a heat pump type air conditioner according to the present invention.

FIG. 2 is a characteristic diagram showing a cooling capacity ratio of a refrigeration cycle of a general vapor compression heat pump, a superheat degree of an indoor outlet, and an expansion valve opening ratio of an inlet / outlet temperature difference.

FIG. 3 is a flowchart showing an operation of the heat pump type air conditioner of Embodiment 1 during a cooling operation.

FIG. 4 is a characteristic diagram showing an expansion valve opening ratio of a detected superheat degree SH of a refrigeration cycle of a general vapor compression heat pump.

FIG. 5 is a configuration diagram of a heat pump type air conditioner according to a second embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a cooling capacity ratio of a refrigeration cycle of a general vapor compression heat pump, a superheat degree of an indoor outlet, and an expansion valve opening ratio of an inlet / outlet temperature difference.

FIG. 7 is a flowchart showing the operation of the heat pump type air conditioner of Embodiment 2 during the cooling operation.

FIG. 8 is a configuration diagram of Embodiment 3 of the heat pump type air conditioner according to the present invention.

FIG. 9 is a flowchart showing the operation of the heat pump type air conditioner of Embodiment 3 during the cooling operation.

FIG. 10 is a configuration diagram of a heat pump air conditioner according to a fourth embodiment of the present invention.

FIG. 11 is a flowchart showing the operation of the heat pump type air conditioner of Embodiment 4 during the cooling operation.

FIG. 12 is a refrigeration system diagram of a conventional heat pump type air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 Outdoor heat exchanger 4 Outdoor blower 5 Refrigerant splitter 7 Indoor heat exchanger 8 Indoor blower A, B Indoor unit Cnt1 1st control means Cnt2 2nd control means Cnt3 3rd control means Cnt4 4th control means CMcnt compression Machine operation control means EV Pulse type electric expansion valve EVcnt Expansion valve control means Mode Operation mode detection means Th1 Indoor inlet pipe temperature sensor Th2 Indoor outlet pipe temperature sensor TM Time detection means Tsens Pipe temperature detection means

Claims (4)

[Claims] The compressor comprises: an outdoor unit including a compressor, an outdoor heat exchanger, an outdoor blower, and an expansion valve; and an indoor unit including a refrigerant distributor, an indoor heat exchanger, and an indoor blower. , The outdoor heat exchanger, the expansion valve,
In a cooling cycle in which the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in an annular manner by a refrigerant pipe to circulate the refrigerant, the refrigerant is installed in a refrigerant pipe between the expansion valve and the refrigerant flow divider. An indoor inlet pipe temperature sensor, an indoor outlet pipe temperature sensor installed at an outlet collecting pipe of the indoor heat exchanger, a pipe for converting an output from the indoor inlet pipe temperature sensor, and an output from the indoor outlet pipe temperature sensor into a temperature signal. Temperature detection means, operation mode detection means for detecting an operation mode of the cooling cycle, time detection means for outputting a signal when a predetermined time has elapsed from the start of operation of the compressor, and operation / stop of the compressor. Compressor control means, expansion valve control means for controlling the degree of opening of the expansion valve, and pressure control based on signals from the pipe temperature detection means, the operation mode detection means and the time detection means. First control means for controlling the compressor control means and the expansion valve control means, wherein the first control means detects the expansion mode by the expansion valve control means when the cooling mode is detected by the operation mode detection means. The valve is fully opened to start the operation of the compressor by the compressor control means, and thereafter, the pipe temperature detection means at the time when the time detection means detects that a predetermined time has elapsed from the start of operation of the compressor. And the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected as the first reference temperature difference, and thereafter, the indoor outlet pipe temperature and the indoor inlet detected by the pipe temperature detecting means during continuous operation of the compressor. From the difference between the inlet and outlet temperature with the pipe temperature,
The result obtained by subtracting the reference temperature difference is used as the detected superheat degree, and the expansion valve control means decreases the opening degree of the expansion valve until the detected superheat degree becomes equal to or higher than the first predetermined superheat degree. An opening that is larger by a first predetermined opening than the opening of the expansion valve when the degree of superheating is equal to or greater than the first predetermined superheating degree is obtained, and the obtained opening is used as a subsequent opening of the expansion valve. A heat pump type air conditioner characterized by controlling the expansion valve control means. 2. The compressor, comprising: an outdoor unit including a compressor, an outdoor heat exchanger, an outdoor blower, and an expansion valve; and an indoor unit including a refrigerant flow divider, an indoor heat exchanger, and an indoor blower. , The outdoor heat exchanger, the expansion valve,
In a cooling cycle in which the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in an annular manner by a refrigerant pipe to circulate the refrigerant, the refrigerant is installed in a refrigerant pipe between the expansion valve and the refrigerant flow divider. An indoor inlet pipe temperature sensor, an indoor outlet pipe temperature sensor installed at an outlet collecting pipe of the indoor heat exchanger, a pipe for converting an output from the indoor inlet pipe temperature sensor, and an output from the indoor outlet pipe temperature sensor into a temperature signal. Temperature detection means, operation mode detection means for detecting an operation mode of the cooling cycle, time detection means for outputting a signal when a predetermined time has elapsed from the start of operation of the compressor, and operation / stop of the compressor. Compressor control means, expansion valve control means for controlling the degree of opening of the expansion valve, and the pressure control based on signals from the pipe temperature detection means, the operation mode detection means and the time detection means. A second control means for controlling the compressor control means and the expansion valve control means, wherein the second control means controls the expansion by the expansion valve control means when the cooling mode is detected by the operation mode detection means. The valve is fully opened to start operation of the compressor by the compressor control means, and thereafter, the pipe temperature detection means at the time when it is detected by the time detection means that a predetermined time has elapsed from the start of operation of the compressor. The result obtained by adding a predetermined temperature difference to the entrance / exit temperature difference between the indoor exit pipe temperature and the indoor entrance pipe temperature detected as a second reference temperature difference,
The difference obtained by subtracting the second reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means during the subsequent operation of the compressor is defined as a detected superheat degree. The degree of opening of the expansion valve is reduced by the expansion valve control means until the detected degree of superheat is equal to or greater than a first predetermined degree of superheat. A heat pump, wherein an opening degree larger than the opening degree of the expansion valve by a first predetermined opening degree is obtained, and the expansion valve control means is controlled so that the obtained opening degree becomes a subsequent opening degree of the expansion valve. Type air conditioner. 3. The compressor, comprising: an outdoor unit including a compressor, an outdoor heat exchanger, an outdoor blower, and an expansion valve; and an indoor unit including a refrigerant flow divider, an indoor heat exchanger, and an indoor blower. , The outdoor heat exchanger, the expansion valve,
In a cooling cycle in which the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in an annular manner by a refrigerant pipe to circulate the refrigerant, the refrigerant is installed in a refrigerant pipe between the expansion valve and the refrigerant flow divider. An indoor inlet pipe temperature sensor, an indoor outlet pipe temperature sensor installed at an outlet collecting pipe of the indoor heat exchanger, a pipe for converting an output from the indoor inlet pipe temperature sensor, and an output from the indoor outlet pipe temperature sensor into a temperature signal. Temperature detection means, operation mode detection means for detecting an operation mode of the cooling cycle, time detection means for outputting a signal when a predetermined time has elapsed from the start of operation of the compressor, and operation / stop of the compressor. Compressor control means, expansion valve control means for controlling the degree of opening of the expansion valve, and pressure control based on signals from the pipe temperature detection means, the operation mode detection means and the time detection means. Third control means for controlling the compressor control means and the expansion valve control means, wherein the third control means controls the expansion by the expansion valve control means when the cooling mode is detected by the operation mode detection means. The valve is fully opened to start the operation of the compressor by the compressor control means, and thereafter, the pipe temperature detection means at the time when the time detection means detects that a predetermined time has elapsed from the start of operation of the compressor. A result obtained by adding a predetermined temperature difference to an entrance / exit temperature difference between the indoor exit pipe temperature and the indoor entrance pipe temperature detected by the second reference temperature difference,
The result obtained by subtracting the second reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means during the subsequent operation of the compressor as the detected superheat degree, The degree of opening of the expansion valve is reduced by the expansion valve control means until the detected degree of superheat becomes greater than or equal to a first predetermined degree of superheat. An opening degree larger than the opening degree of the expansion valve by a first predetermined opening degree is obtained, and the expansion valve control means is controlled so that the obtained opening degree becomes a subsequent opening degree of the expansion valve. The degree is the first
If the degree of superheat is equal to or greater than a second predetermined degree of superheat, which is smaller than the predetermined degree of superheat, the expansion valve control means is controlled to set the degree of opening of the expansion valve to be larger by the second degree of superposition, and the detected degree of superheat is smaller than zero. In this case, the expansion valve control means is controlled so that the opening degree of the expansion valve is set smaller by the second predetermined degree of opening. If the detected degree of superheat is not less than 0 and less than the second predetermined degree of superheating, the expansion valve is controlled. A heat pump type air conditioner characterized by controlling the expansion valve control means so as to maintain the opening degree of the heat pump. 4. The compressor, comprising: an outdoor unit including a compressor, an outdoor heat exchanger, an outdoor blower, and an expansion valve; and an indoor unit including a refrigerant distributor, an indoor heat exchanger, and an indoor blower. , The outdoor heat exchanger, the expansion valve,
In a cooling cycle in which the refrigerant flow divider, the indoor heat exchanger, and the compressor are sequentially connected in an annular manner by a refrigerant pipe to circulate the refrigerant, the refrigerant is installed in a refrigerant pipe between the expansion valve and the refrigerant flow divider. An indoor inlet pipe temperature sensor, an indoor outlet pipe temperature sensor installed at an outlet collecting pipe of the indoor heat exchanger, a pipe for converting an output from the indoor inlet pipe temperature sensor, and an output from the indoor outlet pipe temperature sensor into a temperature signal. Temperature detection means, operation mode detection means for detecting an operation mode of the cooling cycle, time detection means for outputting a signal when a predetermined time has elapsed from the start of operation of the compressor, and operation / stop of the compressor. Compressor control means, expansion valve control means for controlling the degree of opening of the expansion valve, and pressure control based on signals from the pipe temperature detection means, the operation mode detection means and the time detection means. A fourth control unit for controlling the compressor control unit and the expansion valve control unit, wherein the fourth control unit is configured to control the expansion by the expansion valve control unit when the cooling mode is detected by the operation mode detection unit. The valve is fully opened to start the operation of the compressor by the compressor control means, and thereafter, the pipe temperature detection means at the time when the time detection means detects that a predetermined time has elapsed from the start of operation of the compressor. And the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected as the first reference temperature difference, and thereafter, the indoor outlet pipe temperature and the indoor inlet detected by the pipe temperature detecting means during continuous operation of the compressor. From the difference between the inlet and outlet temperature with the pipe temperature,
The result obtained by subtracting the reference temperature difference is used as the detected superheat degree, and the expansion valve control means decreases the opening degree of the expansion valve until the detected superheat degree becomes equal to or higher than the first predetermined superheat degree. An opening that is larger by a first predetermined opening than the opening of the expansion valve when the degree of superheating is equal to or greater than the first predetermined superheating degree is obtained, and the obtained opening is used as a subsequent opening of the expansion valve. Controlling the expansion valve control means, and thereafter, after the cooling cycle is being detected by the operation mode detection means, and after the compressor is changed from the operation state to the stop state, the operation of the compressor is started again. In this case, the expansion valve control means is controlled so that the opening of the expansion valve is set to be larger by a third predetermined opening than the opening of the expansion valve immediately before the compressor is stopped, and the compression is performed. Restart the machine operation for the time An outlet / inlet temperature difference between the indoor inlet pipe temperature and the indoor outlet pipe temperature detected by the pipe temperature detecting means at the time when it is detected that a predetermined time has elapsed from the start of operation of the compressor by the outlet means is defined as a third reference temperature difference. The result of subtracting the third reference temperature difference from the inlet / outlet temperature difference between the indoor outlet pipe temperature and the indoor inlet pipe temperature detected by the pipe temperature detecting means during the subsequent operation of the compressor is a new detected superheat degree. A heat pump type air conditioner characterized by the following.