JPH07301471A - Reheating type dehumidifying air conditioner - Google Patents

Abstract

PURPOSE:To avoid the instabilization of an operation and a decrease in efficiency in a reheating type dehumidifying air conditioner in which the air after cooling and dehumidifying is reheated by using air conditioning refrigerant. CONSTITUTION:The reheating type dehumidifying air conditioner comprises a dehumidifier D for cooling to dehumidify the air, a reheater H for reheating the dehumidified air by the dehumidifier D, and a plurality of heat pump circuits interposed thermally in series between heat absorbing evaporators 1, 4 which are operated as the function of the dehumidifier D and a radiating condenser for radiating heat. The condenser of a predetermined heat pump circuit disposed at an intermediate or a low-temperature end of a series group of the circuit is split to a relay condenser for heat relay in the group and a condenser Cm for intermediate radiation to radiate heat externally of the group, and the condenser Cm for the intermediate radiation is operated as the function of the reheater H by its radiating operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a dehumidifier for cooling and dehumidifying air, and a reheater for reheating dehumidified air by the dehumidifier, and an endothermic evaporator and a heat dissipation functioning as the dehumidifier. A plurality of heat pump circuits are thermally interposed in series between the heat-radiating condenser and the heat-radiating condenser so that a large temperature difference between the heat-absorbing side and the heat-dissipating side can be achieved with little deterioration of the refrigerant. The present invention relates to a thermal dehumidifying air conditioner.

[0002]

2. Description of the Related Art In the above-mentioned reheat type dehumidifying air conditioner,
The present applicant has previously made the condenser of the heat pump circuit located at the high temperature end in the series group of a plurality of heat pump circuits into two divided structures in order to effectively utilize the heat radiation from the heat dissipation condenser,
A structure was proposed in which one of them functions as the reheater due to its heat radiation effect. This configuration will be further described with reference to FIG. FIG. 5 shows an air conditioner in which two sets of heat pump circuits are thermally connected in series.
1 ′, SA2 ′, a low temperature side heat pump circuit Sb ′ having separate low temperature side evaporating means Eb1 ′, Eb2 ′ for cooling and dehumidifying the introduced air, and a high temperature equipped with an outside air heat radiating condensing means Cao ′ for releasing heat to the outside air. Side heat pump circuit Sa ′ is provided, and the two heat pump circuits S are formed by the relay heat exchanger X ′ in which the low temperature side condensing means Cb ′ and the high temperature side evaporating means Ea ′ of the low temperature side heat pump circuit Sb ′ are integrally configured.
It is configured to transfer heat between a'and Sb '. Then, the pair of low temperature side evaporation means Eb1 ′, Eb
2'and each separate air supply fan F1 ', F2' between each separate reheater C for heating the supply air after dehumidification
ai ₁ ′, Cai ₂ ′ are provided, and the pair of reheaters Ca
i ₁ 'and Cai ₂ ' are the condensing means Cao 'for radiating the outside air
The heat from the high temperature side heat pump circuit Sa ′ is used for reheating by configuring the high temperature side condensing means Ca ′ in a form of being divided by and. The thick black line is
Indicates that the refrigerant state of the part is a high pressure gas phase, the thick line with thin hatching indicates that the refrigerant state of the part is a liquid phase, the thick line with point hatching indicates the refrigerant state of the part Indicates that it is a low pressure gas-liquid two-phase, and the thick white line indicates that the refrigerant state in that portion is a low pressure gas phase. Further, exp1 'to exp3' are expansion valves, and exp4 'to exp6' are expansion valves having a flow rate adjusting function.

[0003]

However, in the above-mentioned conventional reheat type dehumidifying air conditioner, when the dehumidified air is heated by the reheater, the refrigerant condensing temperature in the reheater and the air dehumidified by cooling (recooling) The difference between the temperature of the target air) and the temperature of the target air) becomes larger than necessary, and as a result, the compressor operates under conditions that deviate from the proper operating conditions, resulting in unstable operation and reduced operating efficiency. There was a problem.

In view of the above situation, an object of the present invention is to provide a reheat type dehumidifying air conditioner capable of realizing a structure for reheating in a state in which unstable operation and reduction in operation efficiency are less likely to occur. Especially.

[0005]

A first characteristic constitution of a reheat type dehumidifying air conditioner according to the present invention is a dehumidifier for cooling and dehumidifying air, and a reheater for reheating dehumidified air by this dehumidifier. Provided between the heat-absorbing evaporator that functions as the dehumidifier and the heat-radiating condenser that radiates heat, a plurality of heat-pump circuits are thermally interposed in series, in the series group of the heat-pump circuits, Alternatively, the condenser of the predetermined heat pump circuit located at the low temperature end is divided into a relay condenser that performs heat relay in the series group and an intermediate heat radiation condenser that radiates heat to the outside of the series group, and the intermediate The heat dissipation condenser is configured to function as the reheater by its heat dissipation effect.

A second characteristic configuration of the reheat type dehumidifying air conditioner according to the present invention is, in addition to the first characteristic configuration, a series group of heat pump circuits, and each of the heat pump circuits forming the series group has an individual unit. It is a multi-stage compression type equipped with a refrigerant compressor.

[0007]

In other words, in the conventional reheat type dehumidifying air conditioner, the waste heat of the high temperature side heat pump circuit, which is wastefully discharged to the outside of the circuit, is used to reheat, considering only effective use of waste heat. In fact, it became clear that a very high heat source is not required for reheating, and based on this new finding, in the first characteristic configuration of the present invention, the intermediate in the series group of the heat pump circuits is formed. Alternatively, by allowing the condenser of the heat pump circuit located at the low temperature end to have a split structure and allowing one to function as a reheater, the refrigerant condensing temperature in the reheater part can be reheated while achieving the necessary reheat function. Avoid unnecessarily high temperature compared to the temperature of air.

According to the second characteristic configuration of the present invention,
In addition to that, since each heat pump circuit is equipped with an individual refrigerant compressor, it is possible to adjust the reheat amount by adjusting the reheat amount in the heat pump circuit with the intermediate heat dissipation condenser in the series group of heat pump circuits. The flow rate ratio of the refrigerant to the condenser and the relay condenser is changed, and the operating amount of the refrigerant compressor in the heat pump circuit on the high temperature side is adjusted to cope with the change in the amount of relay heat to the heat pump circuit on the high temperature side. You can change it.

[0009]

Therefore, according to the first feature of the present invention, the reheat operation accompanying cooling and dehumidifying is stably performed and the efficiency is lowered while maintaining the reheat function sufficiently and sufficiently. It is now possible to provide a reheat type dehumidifying air conditioner that can do so.

According to the second characteristic configuration of the present invention,
In the reheat type dehumidifying air conditioner capable of efficient operation described above, the heat pump circuit is provided with an individual refrigerant compressor so that the reheat amount can be changed and adjusted in addition to the change in the refrigerant flow rate ratio. Since it is only necessary to adjust the refrigerant compressor on the high temperature side, which is easy to operate, it is necessary to adjust the reheat amount when using a mixed refrigerant to provide a common refrigerant compressor for multiple heat pump circuits. In addition to changing the refrigerant flow rate ratio, it is necessary to change the effective amount of the refrigerant on the high temperature side, which complicates the operation.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3, a dehumidifier D that cools and dehumidifies air, and a reheater H that reheats dehumidified air by the dehumidifier D.
It shows an air conditioner which is an example of a heat pump type reheat type dehumidifying air conditioner provided with and. FIG. 1 shows the configuration inside the compressor unit U, and FIG. 2 shows a pair of indoor unit units I1,
The internal structure of I2 and the internal structure of the pair of outdoor unit units O1 and O2 are shown in FIG. Between the compressor unit U and both the indoor unit units I1 and I2 and both the outdoor unit units O1 and O2, six spanning pipes p1 to p
It is connected by piping at 6.

As shown in FIG. 2, the first indoor unit I1 has a first heat-absorbing evaporator 1 which acts as a dehumidifier D for cooling and dehumidifying air to the first air-conditioning target area, and its first The first reheat condenser 2 that acts as a reheater H that heats the air that has been cooled and dehumidified by the first heat absorption evaporator 1, and the first heat absorption evaporator 1 and the first reheat condenser 2 Supply the temperature controlled air of S
A first air supply fan 3 that supplies air to the first target area for air conditioning is provided as A1. Further, the second indoor unit I2 includes a dehumidifier D for cooling and dehumidifying the air to the second air conditioning target area.
Second endothermic evaporator 4 acting as a heat exchanger, a second reheat condenser 5 acting as a reheater H for heating the air cooled and dehumidified by the second endothermic evaporator 4, and a second heat absorber A second air supply fan 6 is provided for sending the temperature-controlled air in the second evaporator 4 and the second reheat condenser 5 to the second target area for air conditioning as the supply air SA2. On the other hand, as shown in FIG. 3, the first outdoor unit O1 and the second outdoor unit O2 respectively correspond to separate heat-radiating condensers 7 and 8 that radiate heat to the atmosphere OA. The heat-dissipating condensers 7 and 8 are provided with separate outside air fans 9 and 10 that ventilate the air OA. Further, as shown in FIG. 1, in the compressor unit U, a relay heat exchange provided with a condenser path Xc functioning as a refrigerant condenser and an evaporation path Xe functioning as a refrigerant evaporator, which are configured to be capable of mutual heat exchange. Device X and a pair of compressors Cpa and Cpb
And are provided. Then, the low-boiling-point refrigerant B is circulated through the low-temperature side compressor Cpb in both the heat-absorbing evaporators 1 and 4 of the indoor unit I1 and I2 and the condenser path Xc of the relay heat exchanger X, and the outdoor unit O1. , O2 both heat radiating condensers 7 and 8 and the evaporator path Xe of the relay heat exchanger X.
In addition, the high-boiling-point refrigerant A is circulated by the high-temperature side compressor Cpa, so that between the heat-absorbing evaporators 1 and 4 functioning as the dehumidifier D and the heat-dissipating condensers 7 and 8 that perform heat dissipation, 2
One heat pump circuit Sa, Sb is thermally interposed in series, and a reheat type dehumidifying air conditioner for cooling and dehumidifying the supply air SA1, SA2 with the air OA as a heat radiation destination is constructed.

In the low temperature side heat pump circuit Sb of the series group of heat pump circuits described above, the condenser in the heat pump cycle is provided in the relay heat exchanger X to perform the heat relay in the series group. The condenser path Xc, which is Cr, and the pair of indoor unit units I1 and I2, which serve as an intermediate heat dissipation condenser Cm that radiates heat to the outside of the series group.
It is divided into separate reheat condensers 2 and 5 provided in the above, and in order to make these reheat condensers 2 and 5 function as the reheater H by its heat radiation action, compression is performed on the low temperature side by the cross pipe p2. It is connected to the machine Cpb.

Further, the low temperature side heat pump circuit Sb also has a flow rate adjusting function for the low boiling point refrigerant Bw in the liquid phase state from the condenser path Xc of the pair of reheat condensers 2 and 5 and the relay heat exchanger X. Expansion valves exp1, exp2
exp3 and their expansion valves exp1, exp2, exp
The expansion valve exp for decompressing and expanding the low boiling point refrigerant Bw in the liquid phase state, which has merged and branched after 3 and supplies the low boiling point refrigerant Bwg in the gas-liquid two-phase state of low pressure to the pair of heat absorbing evaporators 1 and 4.
4 and exp5. Further, the high temperature side heat pump circuit Sa has expansion valves exp6 and exp7 having a flow rate adjusting function for the high boiling point refrigerant Aw in the liquid phase from the pair of heat radiating condensers 7 and 8, and the expansion valves exp.
Liquid phase high boiling point refrigerant A collected after 6 and exp 7
w is decompressed and expanded, and the evaporator path Xe of the relay heat exchanger X is expanded.
And an expansion valve exp8 for supplying a low-boiling-point high-boiling-point refrigerant Awg in a gas-liquid two-phase state. In addition, v1 to v27
Is a switching valve that switches the configuration of the refrigerant circulation path according to the operation mode and the like. 1 to 3, a thick black line indicates that the refrigerant state of the portion is a high-pressure gas phase, and a thick hatched thick 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. In addition, the expansion valves exp1 to exp
In 8 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 dehumidifying and cooling operation state of the above-mentioned air conditioner will be described. In the high temperature side heat pump circuit Sa, the high temperature side compressor Cpa sucks in, compresses and discharges the high boiling point refrigerant A in a 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 piping p
1 is passed through 1 to the heat radiation condensers 7 and 8 of the outdoor unit units O1 and O2, and is condensed with the atmosphere OA as a heat radiation target. The high-boiling-point refrigerant Aw in the liquid phase state after condensation reaches the expansion valve exp8 through the crossover 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.
Of the low boiling point refrigerant Bhg in the high-pressure gas phase, which is passed through the evaporator path Xe of FIG. After that, the high-boiling-point refrigerant A in the low-pressure vapor phase state
Is returned to the high temperature side compressor Cpa again, and the above cycle is repeated. On the other hand, 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 to the evaporator path Xc, is condensed for heat dissipation, and the rest is passed through the piping p2 to the indoor unit I.
The air that has passed through the heat-dissipating condensers 2 and 5 of 1 and I2 and is cooled and dehumidified by the heat-absorbing evaporators 1 and 4 is condensed as a heat-dissipation target. The low-boiling-point refrigerant Bw in the liquid phase state after condensation from the condenser path Xc of the relay heat exchanger X and the heat-dissipating condensers 2 and 5 of the indoor unit units I1 and I2 is merged and branched to form an expansion valve. The low-boiling-point refrigerant Bwg in a gas-liquid two-phase state that has reached exp4 and exp5 and has been expanded under reduced pressure is the indoor unit I.
1 and I2 are passed through the heat absorbing evaporators 1 and 4 and are evaporated by using the supply air SA1 and SA2 to the air conditioning target area as heat absorbing sources. 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.

As described above, the reheat condensers 2 and 5 functioning as the reheater H are configured as the intermediate heat radiating condenser Cm obtained by dividing the condenser of the low temperature side heat pump circuit Sb. When reheating the air that has been cooled and dehumidified by the heat-absorption evaporators 1 and 4, it is possible to prevent the difference between the air temperature and the refrigerant condensing temperature from becoming larger than necessary, thereby making the operation unstable and It is possible to prevent a decrease in efficiency.

Further, in the configuration described in this embodiment, the low temperature side heat pump circuit Sb is connected to the low temperature side compressor Cpb.
Is provided, and the high temperature side compressor C is provided in the high temperature side heat pump circuit Sa.
Since the multistage compression type is provided with pa, when adjusting the reheat temperature, the flow rate ratio of the low boiling point refrigerant B is changed by using the expansion valves exp1 to exp5 in the low temperature side heat pump circuit Sa, and changes accordingly. In order to compensate the relay heat in the relay heat exchanger X, the high temperature side heat pump circuit Sb
Therefore, the operation amount of the high temperature side compressor Cpa may be changed, and the operation is simple as compared with the type using a mixed refrigerant described later.

Next, an embodiment in which the present invention is applied to a structure using a mixed refrigerant will be shown. In FIG. 4, the same functions and states as those in the previous embodiment are designated by the same reference numerals.
The thick line with thick hatching indicates that the state of the refrigerant in that portion is high-pressure gas-liquid two-phase.

In this structure, the low-temperature side heat pump circuit Sb and the high-temperature side heat pump circuit Sa are provided with a common compressor Cmp, and the high-pressure vapor phase two-type refrigerant discharged from the compressor Cmp in a mixed state. Ahg, Bhg
Are sequentially condensed from the refrigerant A having the highest boiling point. That is, the compressor Cmp sucks the two kinds of refrigerants A and B in a mixed state, compresses them, and discharges them. The high-pressure gas-phase refrigerants Ahg and Bhg from the compressor Cmp are passed through the heat-dissipating condenser 7, and only the high-boiling-point refrigerant A is condensed with the air OA as a heat-dissipation target, and the liquid-phase refrigerant Aw and the high-pressure gas-phase refrigerant Bh.
and g are sent to the gas-liquid separator Sp. The liquid-phase refrigerant Aw and the high-pressure gas-phase refrigerant Bhg from the heat-dissipating condenser 7 are separated by the gas-liquid separator Sp, and the high-pressure gas-phase refrigerant Bhg is reheated by the condenser path Xc of the relay heat exchanger X. Flow to the condenser 2 for use. On the other hand, the liquid-phase refrigerant Aw is appropriately distributed by the expansion valve exp11 and the expansion valve exp12, and after being decompressed and expanded to the low-pressure gas-liquid two-phase refrigerant Awg, the evaporators of the relay heat exchanger X are respectively. Path Xe and second indoor unit I
The heat is passed through the heat absorbing evaporator 2. In the condenser path Xc of the relay heat exchanger X, the high-pressure gas-phase refrigerant Bh is used with the gas-liquid two-phase refrigerant Awg flowing in the evaporator path Xe as a heat source.
g is condensed, and the liquid-phase refrigerant Bw is sent to the liquid receiver R. Further, in the reheat condenser 2, the refrigerant Bw that has been condensed into a liquid phase by condensing the air that has been cooled and dehumidified in the heat absorption evaporator 1 as a heat radiation target is also sent to the liquid receiver R. on the other hand,
In the evaporator path Xe, the gas-liquid two-phase refrigerant A is used with the high-pressure gas-phase refrigerant Bhg flowing in the condenser path Xc as a heat absorption source.
The wg is evaporated to become a low-pressure gas-phase refrigerant Acg, which is returned to the compressor Cmp via the refrigerant passage 11 of the gas-liquid separator Sp.

[Other Embodiments] Next, still another embodiment of the present invention will be described.

<1> In the above embodiment, the low temperature side heat pump circuit Sb and the high temperature heat pump circuit Sa are provided between the heat absorbing evaporators 1 and 4 functioning as the dehumidifier D and the heat radiating condensers 7 and 8. The above two heat pump circuits are thermally interposed in series, but in place thereof, three or more heat pump circuits may be thermally interposed in series. Then, in that case, the intermediate heat dissipation condenser Cm functioning as the reheater H may be configured such that the condenser of the heat pump circuit located at the middle or low temperature end is divided by the relay condenser Cr. . Further, the refrigerant to be used, if it is a mixed refrigerant in the previous embodiment, it is necessary to use different types of refrigerants having different boiling points, but in the case where a plurality of heat pump circuits are independent in a multi-stage compression format, Different types having different boiling points may be used, or a single refrigerant may be used with different boiling points depending on the pressure condition of each heat pump circuit.

<2> The dehumidifier D for cooling and dehumidifying is not limited to the one in which the supply air SA1, SA2 is ventilated by the supply air fans 3, 6 and is supplied to the first and second air-conditioning target areas by the duct type. Instead, it may be arranged in the air conditioning target area to directly control the temperature of the air conditioning target air.

<3> The object of heat radiation outside the circuit is not limited to the atmospheric air OA, but water, other liquids, etc. can be appropriately changed. The temperature control target air and the dehumidification target air are the air supply S to the first air conditioning target area.
Like the air supply SA2 to A1 and the second air conditioning target area, it is not necessary to be separated into the first air conditioning target area and the second air conditioning target area, and the same air or the same object may be used.

<4> In the claims, reference numerals are given for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the accompanying drawings by the entry.

[0025]

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a refrigerant flow around a compressor unit.

FIG. 2 is a circuit diagram showing a refrigerant flow around an indoor unit.

FIG. 3 is a circuit diagram showing a refrigerant flow around an outdoor unit.

FIG. 4 is a circuit diagram showing a refrigerant flow of another embodiment.

FIG. 5 is a circuit diagram showing a refrigerant flow in a conventional example.

[Explanation of symbols]

 1 Evaporator for heat absorption 2 Evaporator for heat absorption 7 Condenser for heat dissipation 8 Condenser for heat dissipation D Dehumidifier H Reheater Sa Heat pump circuit Sb Heat pump circuit Cr Relay condenser Cm Intermediate heat dissipation condenser

Claims (2)

[Claims] 1. A dehumidifier (D) for cooling and dehumidifying air,
A reheater (H) that reheats the dehumidified air by the dehumidifier (D) is provided, and the heat-absorbing evaporators (1) and (4) that function as the dehumidifier (D) and the heat-dissipating condensate that dissipates heat. Bowl (7),
Between (8) and a plurality of heat pump circuits (Sa),
(Sb) is a reheat type dehumidifying air-conditioner thermally interposed in series, wherein a condenser of a predetermined heat pump circuit (Sb) located at an intermediate or low temperature end in the series group of the heat pump circuits is
Relay condenser (Cr) for relaying heat in the series group and intermediate heat dissipation condenser (Cm) for radiating heat to the outside of the series group
A reheat-type dehumidifying air conditioner having a configuration in which the condenser for intermediate heat dissipation (Cm) is made to function as the reheater (H) by its heat dissipation effect. 2. The series group is of a multi-stage compression type in which each of the heat pump circuits (Sa), (Sb) constituting the series group is provided with an individual refrigerant compressor (Cpa), (Cpb). The reheat type dehumidifying air conditioner described.