JPH07301474A - Heat absorber - Google Patents

Abstract

PURPOSE:To prevent a plurality of heat absorbers from simultaneously becoming iced states by providing the plurality of the absorbers, and ice melting means for ice melting the absorbers becoming iced states, and operating the plurality of the absorbers at the time of a steady heat absorbing operation in the state that constant load heat absorbing capacities per unit heat transfer area are different from each other. CONSTITUTION:Refrigerant Mhg from a compressor Cmp is fed to heaters Ha-Ha of indoor units Ia-Ic via an oil separator Os, etc., in the steady heat absorbing operation state at the time of heating, and the refrigerant Mw condensed here is distributed to arrive at expansion valves exd, exe. The refrigerant Mw of pressure-reduced and expanded vapor two-phase state is fed to heat absorbers Ra, Rb of outdoor units Oa, Ob to evaporate the atmosphere OA as a heat absorption source. In this case, both the absorbers Ra, Rb are so operated that constant load heat absorbing capacities per unit heat transfer area are difference between the absorbers Ra and Rb. A refrigerant circulating passage is switched when any absorber becomes an iced state, and the absorber of the iced side is so controlled as to be ice melted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat absorbing device provided with a plurality of heat absorbers for absorbing heat from a low temperature heat absorbing source and an ice thawing means for thawing the frozen heat absorbers.

[0002]

2. Description of the Related Art In a general heat pump circuit having a heat absorber that absorbs heat from a low-temperature heat source, the vaporization temperature of the refrigerant is lower than the temperature of the low-temperature heat source during heating operation, and the heat sink circuit adheres to the heat absorber. As a means of defrosting to remove frost and ice, by changing the supply destination of the refrigerant from the compressor from the heater to the heat absorber, the heat absorber functions as a condenser to generate heat, and the hot gas method is used. It has been practiced to provide operation switching means for performing ice operation.

This structure will be further described with reference to the drawings. As shown in FIGS. 13 and 14, the heater H'provided in the indoor unit I'and the heat absorber R'provided in the outdoor unit O'are covered. The compressor Cmp 'and the expansion valves exp1' and exp2 'are interposed to constitute an air conditioner. FIG. 13 shows the heating operation, and by supplying the high-pressure vapor-phase refrigerant Mhg ′ from the compressor Cmp ′ to the heater H ′, the heater R ′ functions as a heat dissipation condenser to generate heat. The liquid-phase refrigerant Mw ′ after passing through the heater H ′ is connected to the expansion valve exp1 ′,
By passing through the exp2 ′ and decompressing and expanding it into a low-pressure gas-liquid two-phase state and supplying it to the heat absorber R ′, the heat absorber R ′ functions as an endothermic evaporator to absorb heat, and then passes through the heat absorber R ′. The low-pressure gas-phase refrigerant M ′ after the recirculation is recirculated to the compressor Cmp ′ through the accumulator A ′ so that the steady endothermic operation is performed. On the other hand, FIG. 14 shows the operation for thawing, and the high-pressure gas-phase refrigerant Mhg ′ from the compressor Cmp ′ is supplied to the heat absorber R ′ by switching the configuration of the refrigerant circulation path from the above-described steady heat absorption operation state. The flow of the refrigerant is changed so that the heat absorber R ′ is caused to function as a condenser to generate heat to perform the deicing.

However, in such a structure, since there is only one heat absorber, heat cannot be absorbed during the defrosting operation to remove frost and ice attached to the heat absorber, and heating is performed. Since it is not possible to continue, by providing a plurality of heat absorbers, and by installing the plurality of heat absorbers, for example, by directing them in different directions as shown in FIG. It is possible to avoid that all of the heat sinks become frozen at the same time so that even if some of the heat absorbers are performing the deicing operation, steady heat absorption operation can be performed using the remaining heat absorbers. Has been.

[0005]

However, in the structure in which a plurality of heat absorbers are provided by making the installation directions different from each other as described above, avoiding the simultaneous appearance of the frozen state of all the heat absorbers is only stochastically. There was a possibility that it would not be possible to maintain continuous heating operation, because it was only expected and lacked certainty, and there were restrictions on installation conditions.

In view of the above situation, an object of the present invention is to reliably prevent a plurality of heat absorbers from being frozen at the same time,
It is to provide a heat absorbing device that enables continuous heating to be continued as long as possible.

[0007]

A first characteristic configuration of a heat absorbing device according to the present invention is a plurality of heat absorbers that absorb heat from a low temperature heat absorbing source, and an ice thawing means that thaws the heat absorbers in a frozen state. And a control means for causing the plurality of heat absorbers to absorb heat in a state where the constant load heat absorption capacities per unit heat transfer area are different from each other during steady heat absorption operation in which the deicing means is in a non-operating state. It is in.

A second characteristic configuration of the heat absorbing device according to the present invention is the same as the first characteristic configuration described above, in which the control means controls the unit transmission of a plurality of the heat absorbers having a newer history of defrosting by the defrosting means. In order to reduce the constant load heat absorption capacity per heat area, the ratio of the constant load heat absorption capacity per unit heat transfer area of the heat absorbers is changed every time there is thawing by the thawing means. is there.

On the other hand, the third characteristic constitution of the heat absorbing device according to the present invention is applied to a constitution in which an outside air fan for circulating the outside air as a low temperature heat absorption source to the heat absorber is provided for each of the plurality of heat absorbers. In this case, in the first characteristic configuration or the second characteristic configuration described above, the control means adjusts the blowing amount of each of the plurality of outside air fans, and the constant load heat absorption capacity per unit heat transfer area of each of the heat absorbers. Is to be adjusted individually.

A fourth characteristic configuration of the heat absorbing device according to the present invention is the one of the above-mentioned first characteristic configuration to third characteristic configuration, wherein the control means is provided for each of the plurality of heat absorbers. The constant load heat absorption capacity per unit heat transfer area of each of the heat absorbers is individually adjusted by adjusting the amount of refrigerant supplied to the heat absorbers.

Further, a fifth characteristic configuration of the heat absorbing device according to the present invention is the one of the above-mentioned first characteristic configuration to fourth characteristic configuration, wherein the control means is provided for each of the plurality of heat absorbers. In the constitution, the refrigerant vaporization temperature is changed to individually adjust the constant load heat absorption capacity per unit heat transfer area of each of the heat absorbers.

[0012]

According to the first characteristic configuration of the present invention, the constant load heat absorption capacity per unit heat transfer area between the plurality of heat absorbers is changed to operate, that is, the plurality of heat absorbers are operated. By letting some work more and the rest less work, you can ensure that the heat sinks that worked a lot get iced before the ones that don't work a lot.

According to the second characteristic constitution of the present invention, the ratio of the constant load heat absorption capacity per unit heat transfer area among a plurality of heat absorbers is changed every time there is a thaw, and the history of the thaw is new. Since the constant load heat absorption capacity per unit heat transfer area becomes lower as much as possible, the end of the defrosting is always done by working more heat absorbers that have not yet been thawed. The normal endothermic operation state in which any one of the heat absorbers is used alternately is made to accelerate the transition of the heat absorber to the frozen state and delay the transition of the thawed ice cube to the frozen state. Can be maintained.

According to the third characteristic configuration of the present invention, the heat-absorbers corresponding to the outside-air fan having a large amount of air-blowing are adjusted by adjusting the air-blowing amount of each of the outside-air fans provided separately for the plurality of heat absorbers. It can be made to work to get into the freezing state first, and the operation for surely setting the freezing time among a plurality of heat absorbers can be performed only by adjusting the blow rate of the outside air fan.

According to the fourth characteristic configuration of the present invention, the refrigerant supply amount to each of the plurality of heat absorbers can be adjusted so that the heat absorber having the larger refrigerant supply amount works more and becomes the freezing state first. The operation for surely changing the ice formation time among the plurality of heat absorbers can be performed only by the valve operation for adjusting the refrigerant supply amount.

According to the fifth characteristic configuration of the present invention, since the refrigerant evaporating temperature in each of the plurality of heat absorbers is made different, the amount of refrigerant supplied to each heat absorber may always remain the same. It is possible to reduce the occurrence of pressure loss as compared with the case where the valve opening degree is adjusted for adjustment.

[0017]

As described above, according to the first characteristic configuration of the present invention, all of the plurality of heat absorbers can be obtained by first putting the heat absorber having a large constant load heat absorption capacity per unit heat transfer area into the icing state. It is possible to prevent the simultaneous defrosting operation at the same time or the simultaneous operation of the deicing operation performed in response to the detection of the defrosting operation, and it is possible to avoid a large decrease in the heat absorption capacity or a state where the heat absorption cannot be performed. It has become possible to provide a heat absorbing device that can perform reliable continuous operation.

According to the second characteristic configuration of the present invention,
While performing the deicing operation for some heat absorbers, repeating the operation conditions between the heat absorbers each time the ice is thawed to make sure that the ice formation times differ among multiple heat absorbers. Even if it is in a severe cold state where frequent ice formations occur, it is possible to more reliably and reliably prevent the endothermic capacity from decreasing or not absorbing heat even for a long period of time. It has become possible to provide an excellent heat absorbing device capable of maintaining continuous operation.

On the other hand, according to the third characteristic configuration of the present invention,
The adjustment operation for enabling the continuous operation described above can be performed only by adjusting the air flow rate of the outside air fan without changing the flow of the refrigerant, and thus can be performed by a simple operation without causing a complicated structure.

According to the fourth characteristic configuration of the present invention,
Since the adjustment operation for enabling continuous operation described above is performed by changing the refrigerant flow, it can be applied to a natural ventilation type that does not adopt a configuration in which outside air as a low temperature heat absorption source is ventilated by an outside air fan.

Further, according to the fifth characteristic configuration of the present invention, the adjusting operation for enabling the above-described continuous operation is performed.
Since it is performed by changing the evaporation temperature of the refrigerant without changing the flow of the refrigerant, in addition to being applicable to the natural ventilation type,
By not causing pressure loss of the refrigerant, more efficient continuous operation becomes possible.

[0022]

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

[First Embodiment] FIGS. 1 to 3 show a heat pump type air conditioner incorporating a heat absorbing device provided with a plurality of heat absorbers R for absorbing heat from a low temperature heat absorbing source. This air conditioner includes a pair of outdoor unit units Oa and Ob and three indoor unit units Ia, Ib and Ic which constitute the heat absorbing device.
And a compressor unit Cu interposed between the two units, and three crossover pipes pa, pb, p provided between the units.
and c. FIG. 1 shows a steady heat absorption operation state in which heating is performed using three indoor unit units Ia, Ib, Ic, and FIGS. 2 and 3 show a pair of outdoor unit units Oa, O.
The ice-melting operation state which thaws the heat absorber R in b is shown.

The three indoor unit units Ia, Ib, Ic respectively have heaters Ha, H which function as condensers and generate heat.
b, Hc, and air supply fans Fia, Fib, Fic for supplying temperature-controlled air by the heaters Ha, Hb, Hc to the respective air-conditioning target areas as air supply SAa, SAb, SAc. Note that ha, hb, hc are the heaters Ha,
This is a reheater for heating the air dehumidified by cooling by causing Hb and Hc to function as an evaporator during cooling operation. Each of the pair of outdoor unit units Oa and Ob has a heat absorber R (Ra, R) which functions as an evaporator and absorbs heat from the atmosphere OA which is a low temperature heat absorption source.
b) and a separate outside air fan Fo (Foa, Fob) that ventilates the atmosphere to the corresponding heat absorber R (Ra, Rb). In addition, a compressor Cmp that pressurizes and sends out the refrigerant to the compressor unit Cu, an oil separator OS that separates mist-like oil from the refrigerant from the compressor Cmp and returns it to the compressor Cmp, An accumulator A is provided for removing the liquid-phase refrigerant at the time of incomplete evaporation from the low-pressure gas-phase refrigerant that is returned to the compressor Cmp. And
Heaters Ha, Hb of the indoor unit Ia, Ib, Ic,
Hc and heat absorbers Ra and Rb of the outdoor unit Oa and Ob
In addition, the refrigerant is circulated by the compressor Cmp, and the atmosphere OA
A heat pump circuit for controlling the heating temperature of the supply air SAa, SAb, SAc by using as a heat absorption source is configured. This heat pump circuit includes heaters Ha, Hb, Hc during steady heat absorption operation.
Expansion valves exa, exb, and exc that also have a flow rate adjusting function for the liquid-phase refrigerant Mw from
Liquid-phase refrigerant M branched and joined after passing through a, exb, and exc
Expansion valves exd and exe are provided to expand w under reduced pressure and supply the low pressure gas-liquid two-phase refrigerant Mwg to the heat absorbers Ra and Rb. In addition, va to vm are switching valves exf, exg, e that switch the configuration of the refrigerant circulation path according to the operation mode and the like.
xh is an expansion valve used during cooling operation. 1 to 3, the thick black line indicates that the state of the refrigerant in that portion is the high pressure gas phase, and the thick line with thin hatching indicates
The refrigerant state of the part indicates that it is in the liquid phase, the thick line with dot hatching indicates that the refrigerant state of the part is low-pressure gas-liquid two-phase, and further, the thick white line indicates that part. Shows that the refrigerant state of is a low pressure gas phase. Further, in the expansion valves exa to exh and the switching valves va to vm,
The white ones show the flowing state of the refrigerant, and the black ones show the non-flowing state or the closed state.

Next, the steady-state heat absorption operation state during heating of the air conditioner will be described with reference to FIG.

The compressor Cmp sucks in, compresses and discharges the refrigerant M in a low-pressure gas phase. The refrigerant Mhg in the high-pressure gas phase from the compressor Cmp is the oil separator O.
After passing through S, the indoor unit I through the pipe pc
a, Ib, Ic heaters Ha, Hb, Hc flow,
The air supply SAa, SAb, SAc to the air conditioning target area is condensed as a heat dissipation target. Refrigerant Mw in liquid phase after condensation
Is diverted through the crossover pipe pa and expanded valves exd, e
xe, the refrigerant Mwg in a gas-liquid two-phase state that has been decompressed and expanded
Is passed through the heat absorbers Ra and Rb of the outdoor unit Oa and Ob, and is evaporated by using the atmosphere OA as a heat absorption source. After that, the refrigerant M in the low-pressure gas phase is returned to the compressor Cmp after passing through the accumulator A through the crossover pipe pb,
The cycle described above is repeated.

In the steady heat absorption operation during heating as described above, in order to avoid a situation in which the heat absorption capability of the pair of heat absorbers Ra and Rb is simultaneously frozen, the heat absorption capacity of the both heat absorbers Ra and Rb is significantly reduced. The constant load heat absorption capacities per unit heat transfer area are made to differ from each other during operation. Specifically, the air OA is applied to both heat absorbers Ra and Rb.
The amount of air blown by each of the outside air fans Foa and Fob through which air is ventilated is made different, and the heat absorber having the larger amount of ventilated air is first put into the frozen state.

When any one of the heat absorbers becomes in an icing state, the structure of the refrigerant circulation path is continuously switched, and the heat sinks in the icing state are caused to function as a condenser to generate heat, so that the heat absorbers are It is configured to be operated in the thaw mode. next,
The ice-breaking operation state will be described.

FIG. 2 shows that the amount of air blown by the second outside air fan Fob is larger than that of the first outside air fan Foa, so that the second heat absorber R is shown.
The second outdoor unit thawing operation state performed in response to the icing state of b is shown.

The compressor Cmp draws in, compresses and discharges the refrigerant M in a low-pressure gas phase. The refrigerant Mhg in the high-pressure gas phase from the compressor Cmp is the oil separator O.
After passing through S, the flow is divided via the crossover pipe pc, and is passed to the heaters Ha, Hb, Hc and the second heat absorber Rb of the indoor unit Ia, Ib, Ic, and the heaters Ha, Hb, Hc.
Then, the supply air SAa, SAb, SAc to the air conditioning target area is condensed as a heat dissipation target. On the other hand, the second supply device Rb functions as a condenser to generate heat, which causes the second heat absorber Rb to thaw. The refrigerant Mw condensed in the heaters Ha, Hb, Hc and the second heat absorber Rb to be in a liquid phase state is merged, and the expansion valve ex is passed through the cross pipe pa.
After reaching d, the refrigerant Mwg in a gas-liquid two-phase state after being expanded under reduced pressure is passed through the first heat absorber Ra and evaporated using the atmosphere OA as a heat absorption source. After that, the refrigerant M in the low-pressure vapor phase state is returned to the compressor Cmp again after passing through the accumulator A through the cross pipe pb, and the above-described cycle is repeated. As described above, the heater H of the indoor unit Ia, Ib, Ic while absorbing heat using the first heat absorber Ra even during the deicing operation with the second heat absorber Rb functioning as a condenser.
The heating using a, Hb, and Hc can be continuously performed.

Now, when the second outdoor unit deicing operation is completed,
Again returning to the steady endothermic operation shown in FIG. 1, at this time, unlike the previous case, the blowing amount of the first outside air fan Foa is made larger than that of the second outside air fan Fob. Then, as a result, the first outdoor unit defrosting operation shown in FIG. 3 is performed in response to the first heat absorber Ra being in the icing state. This first outdoor unit ice thawing operation is the same as the second outdoor unit ice thawing operation described above, except that the heat absorbers that function as the condensers are the same, and the description thereof is omitted. In any case, the structure of the refrigerant circulation path is switched as described above, and the heat absorber R in the frozen state is caused to function as a condenser and is heated to perform the ice-melting operation.

After that, when the first outdoor unit ice thawing operation is completed, the operation returns to the steady heat absorption operation shown in FIG. 1 again, and this time, the blowing amount of the second outside air fan Fob is again set to the first outside air fan Foa.
More than. In this way, each time the ice is thawed, the ratio of the constant load heat absorption capacity per unit heat transfer area of the heat absorbers Ra and Rb is adjusted by adjusting the air flow rates of the outside air fans Foa and Fob, respectively. As described above, the newer the history of deicing, the smaller the above-mentioned capacity is.
Rb is surely prevented from being frozen at the same time so that the heating operation can be continued.

FIG. 4 shows an outline of a control system for performing the switching control of each of the above operating states. The control means CC outputs a control signal to the pair of outside air fans Foa, Fob for changing and adjusting the air flow rates of the outside air fans Foa, Fob. Either outside air fan Foa or Fob
If one of the corresponding heat absorbers R is in the icing state first as described above by increasing the amount of air blown from the other, the detecting means D attached to the heat absorber R detects it and the control means CC The control means CC outputs a control signal to the switching valve to switch the configuration of the refrigerant circulation path to perform the deicing operation as described above. That is, the refrigerant circulation path configuration in which the heat absorber R is made to function as a condenser so as to be heated constitutes the ice thawing means for thawing the heat absorber R in the frozen state. When the thawing operation for the heat absorber R in the icing state is completed, the control means CC again switches the configuration of the refrigerant circulation path to perform the steady heat absorption operation, and at that time, the pair of outside air fans Foa, Fob.
The ratio of the blown air amount is changed to the reverse of that in the steady endothermic operation, and thereafter, the above control is repeated every time the ice is thawed.

[Second Embodiment] FIGS. 5 to 10 show an air conditioner provided with a heat absorber R for absorbing heat from an external heat absorbing source and a heater H for heating an object to be heated. 5 and 8 show the configuration inside the compressor unit U, FIGS. 6 and 9 show the configuration inside the pair of indoor unit units I1 and I2, and FIG. 7 and FIG.
Reference numeral 0 indicates the configuration inside the pair of outdoor unit units O1 and O2, respectively. The compressor unit U and the both indoor unit units I1 and I2 and the both outdoor unit units O1 and O2 are connected by six spanning pipes p1 to p6.
5 to 7 show a steady heat absorption operation state in which heating is performed by using the pair of indoor unit units I1 and I2, and FIGS. 8 to 10 show an ice formation state of the heat absorber R in the pair of outdoor unit units O1 and O2. It shows an ice-breaking operation state performed based on the detection.

As shown in FIGS. 6 and 9, the first indoor unit I1 has a heater H acting as a heat-radiating condenser C for heating air to the first air-conditioning target area to be heated.
The first heater 1 and the first air supply fan 3 for supplying the temperature-controlled air from the first heater 1 as the air supply SA1 to the first air conditioning target area are provided. Reference numeral 2 is a reheater for causing the first heater 1 to function as an evaporator during cooling operation to heat the air that has been cooled and dehumidified. In addition, the second indoor unit I2 includes a second heater 4 that is a heater H that acts as a heat dissipation condenser C that heats air to a second air conditioning target area that is also a heating target, and a second heater 4 thereof. A second air supply fan 6 is provided for supplying the temperature-controlled air from the second heater 4 to the second air conditioning target area as the air supply SA2. Reference numeral 5 is a reheater for causing the second heater 4 to function as an evaporator during cooling operation to heat the air dehumidified by cooling. Meanwhile, FIG. 7 and FIG.
As shown in FIG. 1, the first outdoor unit O1 and the second outdoor unit O2 are the first and second heat absorbers R that function as the heat-absorbing evaporator E that absorbs heat from the atmosphere OA that is a low-temperature heat source. The air conditioners 7 and 8 and the respective outside air fans 9 and 10 that ventilate the air OA to the corresponding heat absorbers 7 and 8 are provided. Further, as shown in FIGS. 5 and 8, the compressor unit U is provided with a condenser path Xc functioning as a refrigerant condenser and an evaporator path Xe functioning as a refrigerant evaporator, which are configured to be capable of mutual heat exchange. The relay heat exchanger X and a pair of compressors Cpa and Cpb are provided.

Then, the high boiling point refrigerant A is circulated in the both heaters 1 and 4 of the indoor unit units I1 and I2 and the evaporator path Xe of the relay heat exchanger X by the high temperature side compressor Cpa, and one outdoor unit unit A second heat absorber 8 of O2, and
The low boiling point refrigerant B is circulated in the condenser path Xc of the relay heat exchanger X by the low temperature side compressor Cpb, and thus two heat pump circuits are provided between the heat absorbing evaporator E and the heat radiating condenser C for radiating heat. Sa and Sb are thermally intervened in series, and the atmosphere O
A heat pump device for controlling the heating temperature of the supply air SA1, SA2 using A as a low temperature heat absorption source is configured. The first heat absorber 7 of the other outdoor unit O1 includes the indoor unit I
The high boiling point refrigerant A returned from both the heaters 1 and 4 of I and I2 is branched and made to flow, and after evaporating and absorbing heat, the high boiling point refrigerant A after passing through the evaporation path Xe of the relay heat exchanger X. It is designed to join.

This is a pair of outdoor unit units O1 and O2.
Since the endothermic capacity of each of the heat absorbers 7 and 8 will be significantly reduced if they become icy at the same time, in order to avoid such a situation, it is possible to make the boiling points of the refrigerants flowing during the normal endothermic operation different from each other. The constant load operating capacities per unit heat transfer area of both heat absorbers 7 and 8 are made different so that the icing times do not overlap with each other. That is, the second heat absorber 8 having the increased capacity, that is, the low boiling point refrigerant B having a large difference from the outside air temperature in this embodiment, is sure to be frozen first. In order to realize the difference in capacity, the high boiling point refrigerant A is made to flow through the one first heat absorber 7, and the low boiling point refrigerant B is made to flow through the other second heat absorber 8.

The low temperature side heat pump circuit Sb also has an expansion valve exp1 having a flow rate adjusting function for the low boiling point refrigerant Bw in the liquid state from the condenser path Xc of the relay heat exchanger X.
And an expansion valve exp2 for decompressing and expanding the low-boiling-point refrigerant Bw in the liquid phase after passing through the expansion valve exp1 and supplying the low-boiling-point refrigerant Bwg in the low-pressure gas-liquid two-phase state to the second heat absorber 8. It is installed. In the high temperature side heat pump circuit Sa, the high boiling point refrigerant A in the liquid phase from the pair of heaters 1 and 4 is supplied.
Expansion valve exp3 that also has a flow rate control function for w
Exp4 and the high-boiling-point refrigerant Aw in the liquid phase, which has merged after passing through the expansion valves exp3 and exp4, are decompressed and expanded, and the evaporator path Xe and the first heat absorber 7 of the relay heat exchanger X are expanded.
In addition, expansion valves exp5 and exp6 are separately provided for supplying a low-boiling-point high-boiling-point refrigerant Awg in a gas-liquid two-phase state. Note that v1 to v27 are switching valves, exp7 and exp8, which switch the configuration of the refrigerant circulation path according to the operation mode and the like.
Is a switching valve that switches the expansion valve used during the cooling operation. 5 to 10, a black thick line indicates that the refrigerant state of the portion is a high-pressure gas phase, and a thick hatched line indicates that the refrigerant state of the portion is a liquid phase, The thick line with dot hatching indicates that the refrigerant state of that portion is low-pressure gas-liquid two-phase, and the thick white line indicates that the refrigerant state of that portion is low-pressure vapor phase. Further, in the expansion valves exp1 to exp8 and the switching valves v1 to v27, the white ones show the flowing state of the refrigerant, and the black ones show the non-flowing state or the closed state.

Next, the steady heat absorption operation state during heating of the air conditioner will be described with reference to FIGS. 5 to 7. In the high temperature side heat pump circuit Sa, the high temperature side compressor Cpa is
The high-boiling-point refrigerant A in the low-pressure gas phase is sucked, compressed, and discharged. The high-boiling-point high-boiling-point refrigerant Ahg from the high-temperature side compressor Cpa is passed through the pipes p1 to the heaters 1 and 4 of the indoor unit I1 and I2 to supply air to the air conditioning target area SA1. , SA2 are heat-dissipated and condensed. The high-boiling-point refrigerant Aw in the liquid phase state after condensation reaches the expansion valves exp5 and exp6 by being shunted through the pipe p5, and the high-boiling-point refrigerant Awg in the gas-liquid two-phase state that has been decompressed and expanded is transferred to the relay heat exchanger X. The low-boiling-point refrigerant Bhg in a high-pressure vapor state and the atmospheric air OA, which flow through the evaporator path Xe and the first heat absorber 7 of the first outdoor unit O1, and flow through the condenser path Xc.
Are vaporized using the respective heat absorption sources. After that, the high-boiling-point refrigerant A in the low-pressure gas phase from the evaporator path Xe of the relay exchanger X and from the first heat absorber 7 via the pipe p3 is merged, and then the high-temperature side compressor again. Reflux to Cpa and the above cycle is repeated. On the other hand, in the low temperature side heat pump circuit Sb, the low temperature side compressor Cpb is
The low-boiling-point refrigerant B in the low-pressure gas phase is sucked, compressed, and discharged. The high-boiling-point low-boiling-point refrigerant Bhg from the low-temperature side compressor Cpb is passed through the condenser path Xc of the relay heat exchanger x and the vapor-liquid two-phase high-boiling point refrigerant passed through the evaporator path Xe. Awg is condensed as a heat dissipation target. The low-boiling-point refrigerant Bw that has become in the liquid phase state after being condensed from the condenser path Xc of the relay heat exchanger X passes through the expansion pipe ex6 via the expansion pipe ex6.
The low-boiling-point refrigerant Bwg in a gas-liquid two-phase state that has reached p2 and has been expanded under reduced pressure is passed through the second heat absorber 8 of the second outdoor unit O2, and evaporated using the atmosphere OA as a heat absorption source. After that, the low-boiling-point refrigerant B in the low-pressure gas phase is recirculated to the low-temperature side compressor Cpb again through the crossing pipe p4, and the above cycle is repeated.

Now, when it is detected by the detecting means D attached to the heat absorbers 7 and 8 that one of the heat absorbers 7 or 8 is in an icing state while continuing the above-mentioned steady heat absorption operation during heating, The control means CC is configured to switch the operation state from the above-mentioned steady heat absorption operation to the deicing operation in which the heat absorber 7 or 8 in the frozen state is heated by making the condenser function to function as a condenser. As described above, since the constant load operating capacity per unit heat transfer area is different between the different heat absorbers 7 and 8 of the outdoor unit O1 and O2, both heat absorbers 7 and 8 are provided. There will be no overlap in the icing times, and only one of them will be in the icing state and the thawing operation will start accordingly. Next, the defrosting operation state will be described with reference to FIGS. 8 to 10 by taking an example of the defrosting operation of the second heat absorber 8.

In the thawing operation, the low temperature side heat pump circuit S
In b, the low temperature side compressor Cpb sucks in, compresses and discharges the low boiling point refrigerant B in a low pressure gas state. The low boiling point refrigerant Bhg in the high pressure gas phase from the low temperature side compressor Cpb
Is branched and a part of the condenser path Xc of the relay heat exchanger X is
The high-boiling-point refrigerant Awg in the gas-liquid two-phase state, which is passed through the evaporator passage Xe and is condensed as a heat radiation target, and the rest is the second of the second outdoor unit O2 through the crossover pipe p2. By flowing the heat absorber 8 and causing the heat absorber 8 to function as a condenser, frost or ice attached to the second heat absorber B is condensed as a heat radiation target. As a result, deicing is performed. The low-boiling-point refrigerant B in a liquid state after condensation from the condenser path Xc of the relay heat exchanger X via the pipe p6 and from the heat absorber 8 of the second outdoor unit O2.
w is merged and reaches the expansion valve exp6, and the low-boiling-point refrigerant Bwg in a gas-liquid two-phase state that has been decompressed and expanded is passed through the first heat absorber 7 of the first outdoor unit O1, and the outside air OA is used as a heat absorption source. Is evaporated. That is, as described above, the normal endothermic operation can be continuously performed in the first outdoor unit O1 even while the second outdoor unit O2 is being defrosted. After the evaporation, the low-boiling-point refrigerant B in a low-pressure vapor phase state is again passed through the piping p4 to the low-temperature side compressor Cp.
Reflux to b and the above cycle is repeated. On the other hand, in the high temperature side heat pump circuit Sa, the high temperature side compressor Cpa draws in, compresses and discharges the high boiling point refrigerant A in the low pressure gas phase state. The high-boiling-point high-boiling-point refrigerant Ahg from the high-temperature side compressor Cpa is passed through the pipes p1 to the heaters 1 and 4 of the indoor unit I1 and I2 to supply air to the air conditioning target area SA1. , SA2 are heat-dissipated and condensed. The high-boiling-point refrigerant Aw that has become a liquid state after condensation is
The high-boiling-point refrigerant Awg in the gas-liquid two-phase state that has reached the expansion valve exp5 via the crossover pipe p5 and has been decompressed and expanded is passed through the evaporator path Xe of the relay heat exchanger X and through the condenser path Xc. The low-boiling-point refrigerant Bhg in the high-pressure gas phase is evaporated using the heat absorption source. Then, the high-boiling-point refrigerant A in the low-pressure gas state is recirculated to the high temperature side compressor Cpa again, and the above-described cycle is repeated. In this way, the heated air supply S to the air-conditioning target area is performed even during the deicing operation.
The feeding of A1 and SA2 can be continuously performed.

Then, as described above, in performing the thawing operation, in order to heat the heat absorber R in the icing state by functioning as a condenser, the heat absorber R is connected to the heat pump circuits Sa, Sb. Since it is configured to function as a condenser of the low temperature side heat pump circuit Sb of the series circuit group, when the ice is thawed by heating, the difference between the ambient temperature and the refrigerant temperature does not have to be so large, and the refrigerant is excessively condensed. It is possible to prevent the operation from becoming unstable and the efficiency from being lowered due to the operation.

Next, the control for switching the operating state from the above-mentioned steady heat absorption operation to the ice-melting operation will be summarized.
As shown in FIGS. 11 and 12, at the refrigerant outlets of the pair of outdoor unit units O1 and O2, the detection for detecting the icing state of the first and second heat absorbers 7 and 8 functioning as heat absorbers R, respectively. Each of the freezing sensors S1 and S2, which are the temperature sensors serving as the means D, are provided.
The detection signals from S1 and S2 are input to the switching control means CC. From the control means CC, in order to control the switching of the configuration of the refrigerant circulation path according to the above detection signal,
Switching valves v17 to v21 for both outdoor unit units O1 and O2,
It is configured to output a control signal to v23 to v27.

When the second freezing sensor S2 detects that the second heat absorber 8 of the second outdoor unit O2 is frozen, the control means CC switches the switching valves to turn the second heat absorber 8 on. Perform the defrosting operation for the second outdoor unit, which heats by making the condenser function. This is the ice-breaking operation state described above.
This state is shown in FIG. At this time, as described above, the low boiling point refrigerant B is circulated in the first heat absorber 7 to continuously absorb heat.

When the second outdoor unit deicing operation is completed, the high boiling point refrigerant A is circulated through the second heat absorber 8 and the low boiling point refrigerant B is circulated through the first heat absorber 7. In this state,
Next, the first heat absorber 7 comes into a frozen state first. When the first freezing sensor S1 detects that the first heat absorber 7 is in an icing state, the control means CC switches each switching valve to make the first heat absorber 7 function as a condenser and heat the first outdoor. Carry out the ice-breaking operation for the machine. This state is shown in FIG. Then, at this time, the low boiling point refrigerant B is circulated in the second heat absorber 8 to continuously absorb heat.

As described above, the control means CC performs either the first outdoor unit thaw operation or the second outdoor unit thaw operation in accordance with the detection signal from any one of the ice sensors S1 and S2. As described above, the operation state is switched, and the heat absorption is continued using the remaining heat absorber R during the thawing operation.

That is, in the above-described second embodiment, the control means CC has the heat absorber R in the multi-stage compression configuration.
The two types of refrigerants A and B having high and low boiling points which are made to flow through each of them are changed to change the refrigerant evaporation temperature, and the constant load heat absorption capacity per unit heat transfer area of each heat absorber R is individually adjusted. There is.

[Other Embodiments] Next, still another embodiment of the present invention will be described. <1> In both of the above embodiments, the control means CC reduces the constant load heat absorption capacity per unit heat transfer area as the history of the defrosting by the defrosting means of the plurality of heat absorbers R is newer. The description has been given of the configuration in which the ratio of the constant load heat absorption capacity per unit heat transfer area of the heat absorber R is changed every time there is ice thawing by the ice thawing means. The configuration for changing the ratio of the constant load heat absorption capacity per unit transmission area of the container R is omitted,
A configuration may be adopted in which any of the heat absorbers R is controlled so that the above capacity is always high.

<2> In the above first embodiment, when individually adjusting the constant load heat absorption capacity per unit heat transfer area of each of the plurality of heat absorbers R, the blown air amount of each outside air fan Fo is adjusted. Instead of, or in addition to, the configuration described above, a configuration may be adopted in which the capacity of each heat absorber R is adjusted by adjusting the refrigerant supply amount to each heat absorber.

<3> In the above second embodiment, in addition to the configuration of changing the refrigerant evaporation temperature in each of the plurality of heat absorbers R, a configuration of adjusting the blowing amount of each outside air fan Fo,
And, adopting either one of the configurations for adjusting the refrigerant supply amount to each of the heat absorbers R, or both in combination,
The constant load heat absorption capacity per unit heat transfer area of each of the plurality of heat absorbers R may be individually adjusted.

<4> In the second embodiment, the refrigerant evaporation temperature in each of the plurality of heat absorbers R is changed, although not shown, a different compression type refrigerant having different boiling points is mixed to obtain a single compression. You may employ | adopt the structure which circulates using a machine. When a plurality of heat pump circuits are independently provided in a multi-stage compression type as in the second embodiment, the refrigerant evaporation temperature is changed by using different kinds of refrigerants having different boiling points. Alternatively, a single refrigerant may be used with different boiling points depending on the pressure conditions of each heat pump circuit. Further, the refrigerant to be used is not limited to the direct expansion refrigerant such as CFC, but other brine or the like may be used, and when a plurality of heat pump circuit configurations are used, they may be used in combination.

<5> As the deicing means, as in the previous embodiment, the structure of the refrigerant circulation path is changed to replace the structure in which the heat absorber R functions as a condenser, or in addition thereto, for example, A heater through which the high-pressure gas refrigerant Mhg flows or a heater of another heat source may be provided in the vicinity of the heat absorber R, or the stored water for deicing may be stored by the heater through which the high-pressure gas refrigerant Mhg flows or a heater of another heat source. The heat absorber R that is heated and frosted may be sprinkled with water.

<6> As the detecting means D for detecting the frozen state of the heat absorber R, instead of the temperature sensor for detecting the refrigerant outlet temperature as described in the second embodiment, ice is observed by observing the change in the refrigerant outlet pressure. It may be implemented by providing a pressure sensor for determining whether or not the state is present, or by providing an optical sensor for detecting that the reflectance changes due to frost or ice. Further, the detecting means D may be omitted, and the ice-melting operation may be performed manually.

<7> Heaters Ha, Hb, H for heating
c is the air supply S by the air supply fans Fia, Fib, Fic
Aa, SAb, and SAc are not limited to those that are ventilated and sent to the three air conditioning target areas by a duct type, and may be provided in the air conditioning target area to directly heat the air conditioning target air.

<8> The heat absorption source outside the circuit is not limited to the atmosphere OA, but water, other liquids, or the like can be changed as appropriate. The temperature control target air is the first air conditioning target area, the second air conditioning target area, the second air conditioning target area SAb, the third air conditioning target area SAc, or the like. The air-conditioning target area and the third air-conditioning target area do not have to be separated and may be the same air or the same object.

<9> Reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a refrigerant flow during steady heat absorption operation in a first embodiment.

FIG. 2 is a circuit diagram showing a refrigerant flow during a second outdoor unit deicing operation in the first embodiment.

FIG. 3 is a circuit diagram showing a refrigerant flow during a first outdoor unit deicing operation in the first embodiment.

FIG. 4 is a schematic diagram showing a control system in the first embodiment.

FIG. 5 is a circuit diagram showing a refrigerant flow around a compressor unit during steady heat absorption operation in the second embodiment.

FIG. 6 is a circuit diagram showing a refrigerant flow around the indoor unit during steady heat absorption operation in the second embodiment.

FIG. 7 is a circuit diagram showing a refrigerant flow around the outdoor unit during steady heat absorption operation in the second embodiment.

FIG. 8 is a circuit diagram showing a refrigerant flow around a compressor unit during a second outdoor unit deicing operation in the second embodiment.

FIG. 9 is a circuit diagram showing a refrigerant flow around the indoor unit during the second defrosting operation for the outdoor unit in the second embodiment.

FIG. 10 is a circuit diagram showing a refrigerant flow around the outdoor unit during the second defrosting operation for the outdoor unit in the second embodiment.

FIG. 11 is a schematic diagram showing control of an outdoor unit during a second outdoor unit deicing operation in the second embodiment.

FIG. 12 is a schematic diagram showing control of an outdoor unit during a first outdoor unit deicing operation in a second embodiment.

FIG. 13 is a circuit diagram showing a refrigerant flow during a conventional steady heat absorption operation.

FIG. 14 is a circuit diagram showing a refrigerant flow during a conventional deicing operation.

FIG. 15 is a schematic view of a conventional multiple heat absorber installation type.

[Explanation of symbols]

 R Heat absorber CC Control means OA Outside air Fo Outside air fan

Claims (5)

[Claims] 1. A heat absorbing device provided with a plurality of heat absorbers (R) for absorbing heat from a low temperature heat absorbing source, and an ice thawing means for thawing the heat absorber (R) in a frozen state. A control means (CC) is provided for causing the plurality of heat absorbers (R) to absorb heat in a state where the constant load heat absorption capacities per unit heat transfer area are different from each other during the steady heat absorption operation in which the ice means is in the non-operating state. Endothermic device. 2. The control means (CC) reduces the constant load heat absorption capacity per unit heat transfer area as the history of the defrosting by the defrosting means of the plurality of heat absorbers (R) is newer. 2. The heat absorber device according to claim 1, wherein the ratio of the constant load heat absorption capacity per unit heat transfer area of the heat absorbers (R) is changed every time the ice melter is thawed. 3. The control means according to claim 1, wherein each of the plurality of heat absorbers (R) is provided with an outside air fan (Fo) for ventilating the outside air (OA) as the low temperature heat absorption source to the heat absorber (R). (CC) is configured to individually adjust the constant load heat absorption capacity per unit heat transfer area of each of the heat absorbers (R) by adjusting the blowing amount of each of the outside air fans (Fo). 2. The heat absorbing device according to 2. 4. The control means (CC) adjusts a refrigerant supply amount to each of the heat absorbers (R) to individually determine a constant load heat absorption capacity per unit heat transfer area of each of the heat absorbers (R). The heat absorbing device according to claim 1, wherein the heat absorbing device is configured to be adjusted to. 5. The control means (CC) changes the refrigerant evaporation temperature in each of the heat absorbers (R) to individually determine a constant load heat absorption capacity per unit heat transfer area of each of the heat absorbers (R). The heat absorbing device according to claim 1, 2, 3, or 4, wherein the heat absorbing device is configured to be adjusted to.