JP2001116287A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner that can lighten the load of facilities being required for the dew condensation countermeasures of an exhaust duct. SOLUTION: This air conditioner is equipped with a first air channel AF1 that incorporates a heat pump where outdoor air and/or return air is used as a heat source, and extends from a return and opening RA to an air supplying opening SA via a third heat exchanger EX3, a second air channel AF2 that is connected to an outdoor air intake OA, and is merged with the first air channel AF1 at an upstream side as compared with the third heat exchanger EX3, and a third air channel AF3 that is connected to the outdoor air intake OA and/or the return air opening RA, divides flow without passing through the third heat exchange EX3 and is connected to an exhaust opening EA via the first heat exchange EX1. In the air-conditioner, a fourth air channel AF4 is formed between the downstream side of the first heat exchanger EX1 of the third air channel AF3 and the first air channel AF1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly, to a built-in heat pump unit that uses outside air and / or return air as a heat source, and can flexibly respond to an air conditioning load requirement for each individual air conditioning space. The present invention relates to improvement of an exhaust part of a simple air conditioner.

[0002]

2. Description of the Related Art Conventionally, in this type of air conditioner, when a heat pump unit is operated in a cooling cycle,
The first heat exchanger functions as a vapor-liquid contact type evaporative condenser. Therefore, the air that has passed through the first heat exchanger, that is, the exhaust air is high-temperature, high-humidity saturated air. If any temperature drop occurs in the exhaust duct, the moisture in the exhaust condenses in the duct and dew condensation occurs. appear. Therefore, in order to cope with the condensed water that still occurs, it is necessary to provide the exhaust duct with a water-tight structure and to provide a condensed water collecting mechanism in order to cope with the condensed water that still occurs. For this reason, there is a problem that the load on the equipment for the dew condensation countermeasure of the exhaust duct is large.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an air conditioner capable of reducing the load on equipment for preventing dew condensation in an exhaust duct. .

[0004]

In order to solve the above-mentioned problems, the invention according to the first aspect of the present invention has a built-in heat pump that uses outside air and / or return air as a heat source, and has an outside air intake for taking in outside air, and a return from room. A return air inlet for taking in air, an exhaust port for exhausting air to the outside, an air supply port for supplying air to the air-conditioned space, and a gas-liquid contact type for exchanging heat between the exhaust air and the first heat medium. 1 heat exchanger, a second heat exchanger that exchanges heat between the first heat medium and the second heat medium, a compressor, and an expansion valve, and the switching means changes the circulation direction of the first heat medium. A first heat medium circuit that can be switched, a supply air and a second
A third heat exchanger for exchanging heat with the heat medium, a second heat exchanger including at least a second heat exchanger and a circulating pump; A first air flow path that reaches the air supply port through the heat exchanger, a second air flow path that communicates with the outside air intake port and merges with the first air flow path upstream of the third heat exchanger, An air conditioner having a third air flow passage communicating with an intake port and / or a return air port and diverting without passing through a third heat exchanger and communicating with an exhaust port via a first heat exchanger. A fourth air flow path is formed between the third air flow path downstream of the first heat exchanger and the first air flow path.

[0005] As described above, since the fourth air flow path is formed between the downstream side of the first heat exchanger in the third air flow path and the first air flow path, the air returns through the fourth air flow path. Since a part of the air can be mixed with the air that has passed through the first heat exchanger to reduce the relative humidity of the exhaust, dew condensation is less likely to occur in the exhaust duct.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of an air conditioner according to the present invention. As shown in the figure, components such as a heat pump circuit constituting the air heat source type air conditioner are housed in a casing C having a predetermined shape selected according to an installation location. Further, the casing C has an outside air intake OA for taking in outside air, a return air opening RA for taking in return air from the room, and an exhaust port E for exhausting to the outside.
A and an air supply port SA for supplying air to a space to be air-conditioned are provided, and a predetermined air is supplied from an air flow path formed in the casing C through a supply / exhaust facility such as a predetermined duct. Can be supplied and exhausted.

In the casing C, there is provided a first heat medium circulation path (a heat pump circuit using a heat medium utilizing a gas-liquid phase change such as a CFC-based refrigerant or ammonia) constituting a heat pump circuit. Circuit) and a second heat medium circulation path for forming conditioned air (a circuit using water or antifreeze as a heat medium, and may be hereinafter referred to as a "brine circuit"). A spray water circulation path for supplying spray water to a gas-liquid contact type first heat exchanger EX1 described later (a circuit for cooling the first heat exchanger EX1 when it acts as a condenser. The cooling water circuit may be referred to as “cooling water circuit”).

First, the first heat medium circulation path (refrigerant circuit) constituting the heat pump circuit will be described. The first heat medium circulation path includes a gas-liquid contact type first heat exchanger EX1, which performs heat exchange with exhaust air, a compressor COM, a four-way valve QV, and a first heat exchanger.
A second heat exchanger EX for exchanging heat between the heat medium and the second heat medium
2, the first expansion valve EV1, the second expansion valve EV2, and the liquid separator AC are connected by a pipe, and by switching the four-way valve QV, a predetermined refrigerant is circulated in a predetermined direction to circulate a predetermined refrigerant. It constitutes a heat pump circuit. The mechanical first expansion valve EV1 and the second expansion valve EV2 are provided with bypass paths in which the check valves V1 and V2 are inserted, and the expansion valves through which the refrigerant passes according to the circulation direction of the refrigerant. It is possible to choose.

With this configuration, the first heat medium circulation path switches the refrigerant from the compressor COM to the four-way valve QV to the second heat exchanger (condenser) EX2 to the check by switching the four-way valve QV during the heating operation. Valve V1 → second expansion valve EV2 → first
Heat exchanger (evaporator) EX1 → four-way valve QV → liquid separator AC
→ By sequentially circulating with the compressor COM, it is possible to supply heat to a brine circuit described later. On the other hand, during the cooling operation, the four-way valve QV is switched so that the refrigerant is compressed by the compressor COM → the four-way valve QV → the first heat exchanger (condenser) EX1 → the check valve V2 → the first expansion valve EV.
1 → second heat exchanger (evaporator) EX2 → four-way valve QV → liquid separator AC → compressor COM
Cold heat can be supplied to a brine circuit described later.

Next, the second heat medium circulation path (brine circuit) will be described. The second heat medium circulation path is a first heat medium (refrigerant).
And a third heat exchanger EX3 that performs heat exchange between air and a second heat medium (brine), and a pump P1. Then, according to the operation mode of the heat pump circuit, the second heat exchanger EX2 acquires hot or cold heat, and the third heat exchanger EX
By heating or cooling the air supply by means of 3, the optimum temperature control can be performed.

Next, the configuration of the spray water circulation path (cooling water circuit) and the first heat exchanger EX1 of the gas-liquid contact type will be described.
The spray water circulation path includes a spray pipe SP, a cooling water tank (lower water tank) WB for storing the spray water, a pump P2, a pipe line for circulating the cooling water, a strainer attached to a pipe line (not shown), and a spray water. An eliminator for reducing scatter and a water supply pipe for supplementing the amount of scattered and evaporated spray water are provided.

The first heat exchanger EX1 is, for example, an evaporative condenser. The first heat exchanger EX1 removes latent heat of evaporation from the first heat exchanger EX1 by spraying water from the water spray pipe SP to the first heat exchanger EX1. The generated steam is transported by exhaust air to achieve high-density heat transport. The sprinkled cooling water is received by the cooling water tank WB, pumped up by the cooling water pump P2, and sprinkled again from the sprinkling pipe SP to the first heat exchanger EX1. Of course, even if the cooling water is not sprinkled, it is not necessary to operate the spray water circulation path when the heat exchange is sufficiently performed.

Next, the air flow path formed in the casing C will be described. In the air conditioner according to the present embodiment, three air flow paths AF1 and AF
2. AF3 is formed. The first air flow path AF1 is an air flow path connecting the return air port RA and the air supply port SA, and includes a filter F2 for removing dust in the air and a return air damper RD for adjusting the amount of air. Is inserted. The second air passage AF2 is connected to the outside air intake OA and the first air passage AF1.
A filter F1 for removing dust in the air and an outside air intake damper OD for adjusting the amount of air are interposed on the way.

Further, the third air flow path AF3 is provided with an exhaust port EA.
And the first air flow path AF1. However, the third air flow path AF3 is located at a position closer to the return air opening RA than the second air flow path AF2 for introducing outside air.
It is in communication with F1. An exhaust fan EF is provided near the exhaust port EA, and an air supply fan S is provided near the air inlet SA.
F are installed respectively.

Next, the operation of the air conditioner configured as described above will be described. First, air that is taken in from the outside air intake OA and supplied to the air-conditioned space from the air supply port SA is taken into the casing C from the return air port RA. According to the present air conditioner, the exhaust fan E
F, a part of the return air is supplied to the third air flow path A.
It is sent to the gas-liquid contact type first heat exchanger EX1 via F3, where it is exchanged with the first heat medium (refrigerant). And
By driving the first heat medium circulation path (refrigerant circuit) in a predetermined mode (heating mode or cooling mode), hot or cold heat is supplied to the second heat medium flow path (brine circuit), and the third heat exchanger The outside air and / or return air flowing through the first air flow path AF1 is heated or cooled to a desired temperature by the EX3 and supplied to the air-conditioned space.

As described above, since the heat pump mechanism of the present air conditioner uses the exhaust air substantially less than the intake outside air amount as a heat source, the heat pump mechanism exceeds the outside air amount introduced to maintain the indoor air quality in the air-conditioned room. Do not use air as a heat source. Therefore, it is possible to construct a completely independent decentralized air heat source type air conditioner that apparently does not require a heat source. Further, since the heat medium circulating path is configured for each of the heat source and the air conditioning, for example, restrictions on the arrangement of the second heat exchanger EX2 are relaxed, and the degree of freedom of the device configuration is increased. Further, since the first and second heat medium circulating devices can independently control the rotation speeds of the pumps P1 and P2, the responsiveness and the energy saving can be improved from various operation modes by making use of a known control method. The optimal mode can be selected.

The structure and operation of the air conditioner are the same as those of the conventional air conditioner. In the air conditioner having the above configuration, when the heat pump unit is operated in the cooling cycle as described above, the first heat exchanger EX1 acts as a gas-liquid contact type evaporative condenser. Therefore, the first heat exchanger EX1
Since the air that has passed through, i.e., the exhaust air is high-temperature, high-humidity saturated air, if any temperature drop occurs in the exhaust duct,
There is a problem that moisture in the exhaust gas condenses in the duct and dew condensation occurs.

Therefore, a fourth air flow path AF4 is provided between the downstream side of the first heat exchanger EX1 of the third air flow path AF3 and the first air flow path AF1, and air is returned through the fourth air flow path AF4. Part of the return air taken in from the mouth RA is part of the first heat exchanger EX1
To the air that passed through, i.e., the exhaust gas. As described above, by mixing a part of the return air with the exhaust gas, the relative humidity of the exhaust gas can be reduced, so that dew condensation hardly occurs in the exhaust duct.

Assuming that the air conditioner is used for general office air conditioning, the design conditions are as follows: the ratio of the return air volume to the air volume passing through the first heat exchanger EX1 is 6: 1; The condition is temperature 27 ° C / relative humidity 50%, first heat exchanger EX1
The temperature of the air after passing through is 34 ° C./relative humidity 10
Set to 0%.

If, for example, 3.3% of the return air volume is branched into the fourth air flow path AF4 and mixed with the air passing through the first heat exchanger EX1, at a ratio of 0.2: 1, the exhaust gas is exhausted. The air has a temperature of 32.6 ° C./95% relative humidity and a dew point of 32 ° C. Therefore, the dew point temperature drops by 2 ° C. as compared with the case where the air that has passed through the first heat exchanger EX1 is exhausted as it is without mixing the return air, and dew condensation occurs in the exhaust duct even with ordinary heat insulation construction. There is no need to install a watertight duct or a dew condensation water recovery mechanism.

When the return air is mixed with the air that has passed through the first heat exchanger EX1, the exhaust air volume is increased by 20% in the above case as compared with the case where the air is exhausted without mixing. Therefore, the outside air flow increases by 20% in order to secure the air balance. However, the ratio of the outside air load to the total air conditioning load is generally about 20%. The increase in load is 4% of the total air conditioning load, and its effect is negligible.

In implementing the air conditioner according to the present invention, the amount of air passing through the fourth air flow path AF4 is determined in consideration of an increase in external air load and simplification of the exhaust duct from the actually given air-conditioning conditions. As shown in FIG. 2, it is also possible to adjust the fourth air flow path AF4 by inserting an adjustment mechanism such as a motor damper MD so as to obtain an optimum air volume. Also, the first
A check damper CD may be provided to prevent backflow from the downstream side of the heat exchanger EX1 to the first air flow path AF1.

[0023]

As described above, according to the first aspect of the present invention, the fourth air flow path is provided between the downstream side of the first heat exchanger of the third air flow path and the first air flow path. By forming
Part of the return air can be mixed with the air that has passed through the first heat exchanger through the fourth air flow passage to lower the relative humidity of the exhaust gas, thereby reducing the load on the equipment for taking measures against dew condensation in the exhaust duct. The excellent effect that can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an air conditioner according to the present invention.

FIG. 2 is a diagram illustrating a configuration example of a fourth air flow path of the air conditioner according to the present invention.

[Explanation of symbols]

 C Casing EX1 First heat exchanger EX2 Second heat exchanger EX3 Third heat exchanger COM Compressor EV1 First expansion valve EV2 Second expansion valve P1 Pump P2 Pump EF Exhaust fan SF Air supply fan OD Outside air intake Damper RD Return air damper AF1 First air passage AF2 Second air passage AF3 Third air passage AF4 Fourth air passage CD Check damper MD Motor damper

Claims (1)

[Claims] 1. An external air intake, which incorporates a heat pump using external air and / or return air as a heat source, and takes in external air;
A return air port that takes in return air from the room, an exhaust port that exhausts outdoors, an air supply port that supplies air to the air-conditioned space, and gas-liquid contact that exchanges heat between the exhaust air and the first heat medium. A first heat exchanger of a mold and a second heat exchanger for exchanging heat between the first heat medium and the second heat medium.
At least comprises a heat exchanger, a compressor and an expansion valve,
A first heat medium circulating passage capable of switching a circulation direction of the first heat medium by a switching unit;
A third heat exchanger that exchanges heat with a heat medium, a second heat medium circulation path including at least the second heat exchanger, and a circulation pump; A first air flow path that reaches the air supply port through the third heat exchanger, and a first air flow path that communicates with the outside air intake port and merges with the first air flow path at an upstream side of the third heat exchanger. (2) a third air passage communicating with the outside air intake port and / or the return air port and diverting without passing through the third heat exchanger and communicating with the exhaust port via the first heat exchanger; An air conditioner having an air flow path, wherein a fourth air flow path is formed between the third air flow path downstream of the first heat exchanger and the first air flow path. Air conditioner.