JPH0235215B2 - KOONKOSHITSUKUKINOKYOKYUHOHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to cases in which a target space is kept under constant temperature and humidity conditions in a temperature range of 0°C or lower, such as in an ice-warming warehouse, a cold-temperature warehouse, or an environmental testing machine. Particularly suitable for
This relates to a method of supplying constant temperature and constant humidity air to a target space.

Prior Art When supplying constant-temperature, constant-humidity air to a target space that must be maintained at constant temperature and humidity conditions, it is first cooled down to a temperature lower than the target temperature by an air cooler using a refrigeration cycle, and then heated by an electric heater. The temperature is raised by heating with an air reheater such as
Generally, the air is brought to the desired temperature, humidified by a humidifier, adjusted to the desired humidity, and then sent to the desired space. A constant-temperature and constant-humidity air supply machine that is equipped with a blower, an air cooler, an air heater, and a humidifier in such an air flow path forms a series of air circulation flow paths with a constant temperature and humidity chamber that is the target space. are combined like this. Therefore, when it is necessary to maintain a target space in a relatively low temperature state that requires cooling it once below freezing using an air cooler, moisture in the circulating air may reach the air cooler. If you continue to operate continuously, the cooling fins will become clogged with frost, making cooling impossible. I didn't get it. However, this defrosting operation is performed by heating the air cooler, which has the disadvantage that the temperature and humidity conditions of the target space are significantly disturbed. In particular, when humidifying to achieve a constant humidity state, if the controlled temperature of the target space is below freezing, frost may form on the humidifying port, causing the humidification amount to fluctuate, or the moisture released from the humidifier may However, it freezes in the air, making uniform humidification impossible, and creating a stable constant humidity state is extremely difficult.

Composition of the Invention The present invention has been made in view of the above circumstances, and the gist thereof is to install a refrigerant evaporator of a refrigeration cycle as an air cooler and a refrigerant evaporator in an air flow path equipped with a blower. A device comprising a constant-temperature air supply device equipped with an air heater provided on the leeward side of the container, and a constant-temperature and constant-humidity room connected to the constant-temperature air supply device so as to form a series of air circulation channels. A refrigerant heater is provided at an appropriate location in the refrigerant flow path from the refrigerant expander to the refrigerant evaporator in the refrigeration cycle, so that the refrigerant flowing into the refrigerant evaporator can be heated, and the cooled air passing through the refrigerant evaporator can be heated. If the temperature varies, the refrigerant heater is operated to adjust the cooling capacity of the refrigerant evaporator so that the dew point temperature of the air corresponds to the temperature and humidity condition, which is the control target value of the constant temperature and humidity chamber, and the refrigerant evaporator is heated. A method for supplying constant temperature and constant humidity air, characterized in that the air that has passed through is heated by an air heater to raise the temperature to the control target value, and then is supplied to a constant temperature and constant humidity room. .

Hereinafter, the method of the present invention will be explained in detail based on an example of an apparatus for carrying out the present invention, with reference to the drawings.

FIG. 1 conceptually shows an example of an apparatus for implementing the method according to the present invention, in which a partition wall 2 is placed in a box 1 surrounded by a heat insulating wall 1a.
By providing it between the facing side walls, it is divided into a constant temperature and humidity chamber 3 that should be adjusted to the target temperature and humidity conditions and an air flow path 4, and the upper edge 2a of the partition wall 2 and the ceiling of the box 1 are separated. 1b and between the lower edge 2b of the partition wall 2 and the floor surface 1c, a slight gap is provided,
They form an air supply port 4a and an air return port 4b, respectively. The air flow path 4 is configured such that air entering from the air return port 4b rises by a blower 5 provided above, reaches the air supply port 4a, and is supplied to the constant temperature and humidity chamber 3 again. has been done. In such an air flow path 4, a refrigerant compressor 7a, a refrigerant condenser 7
b. Capillary tube 7c as a refrigerant expander
and a refrigerant evaporator 7 of the refrigerator 7a, the refrigerant evaporator 7 is housed as an air cooler,
An air heater 8 consisting of an electric heater is housed on the leeward side of the refrigerant evaporator 7, forming a constant temperature and humidity air supply device. As shown in FIG.
A refrigerant heater 6 is provided, which is formed by winding a heating wire 6a around a conduit 7d and covering the outside with a heat-resistant layer 6b. 10 is a temperature detector such as a thermistor, which detects the temperature of the air supplied into the constant temperature and humidity chamber 3 from the air supply port 4a, inputs this detection signal to the air heater controller 11, and Reference numeral 11 compares a preset target value with an input value, and outputs an output to a drive circuit 12 such as a relay circuit according to the deviation, thereby controlling the operation of the air heater 8. Similarly, 13 is a humidity detector that can maintain accuracy even at subzero temperatures, such as a humidity detector that detects humidity by a change in electrical resistance due to moisture adsorption in a thin film of a polymer compound, and its detection signal is input to the refrigerant heater controller 14, and the drive circuit 15 is activated according to the deviation between the detected value and the set value.
The cooling capacity of the refrigerant evaporator 7 is adjusted by controlling the operation of the refrigerant heater 6 via the refrigerant heater 6.

Using such a device, for example, when trying to maintain the constant temperature and humidity chamber 3 at a temperature of -10°C and a relative humidity of 30%, the cooling capacity of the refrigerant evaporator 7 can be reduced to -
Assuming that air around 10°C can be cooled to around -30°C, the target value is -10°C and humidity 30%.
Since the dew point temperature of air with RH conditions is -23°C, the temperature of the air that enters from the air return port 4b and is cooled after passing through the refrigerant evaporator 7 is set to -23°C. By operating the refrigerant heater 6 to heat the refrigerant, the refrigerant evaporation temperature of the refrigerant evaporator 7 is increased by that amount. Thus, the air that has passed through the refrigerant evaporator 7 reaches the dew point temperature corresponding to the target value and enters the air heater 8, where it is
By being heated to the target temperature, air at -10°C and 30% RH is supplied to the target space with extremely high accuracy.

In the apparatus of the above embodiment, the refrigerant heater is exemplified as one that heats the refrigerant conduit from the outside, but as shown in FIG. , there is a sheathed heater 6 in this
It may be of a type in which d is housed in an air-liquid tight manner.

The feature of the present invention is that thermal energy is directly applied to the air cooler itself to control its cooling capacity,
The temperature of the air passing through this is set to the dew point temperature corresponding to the target value, and by combining this method with the conventional air cooler (refrigerant evaporator) capacity control method, even higher accuracy of temperature and humidity can be achieved. It becomes possible to realize control. For example, a rotary compressor may be used as the refrigerant compressor 7a, and the temperature of the air cooler may be controlled by capacity control using an inverter based on the signal from the temperature detector 10, or the expander 7c may be used as the refrigerant compressor 7a. In order to control the capacity of the air cooler by similarly controlling the refrigerant flow rate by using an electronic linear expansion valve, and furthermore, for the purpose of adjusting the amount of refrigerant to the air cooler, the refrigerant flow path 7d is connected to a plurality of Refrigerant flow rate, such as a method in which the refrigerant inflow rate is roughly controlled by branching into branch flow paths, each of which is provided with an expander and an electromagnetic on-off valve with different flow rates, and each branch flow path is selectively opened and closed. By combining the conventional method of controlling the temperature and humidity with the method of the present invention, it is possible to control temperature and humidity with even higher accuracy.

Note that the humidifier is not necessary for temperature and humidity control under the conditions of the specific example described above, so it is omitted in the embodiment shown in FIG. You can also install a humidifier in a suitable place instead of using it.

Effects Conventional constant-temperature and constant-humidity air supply methods use an air cooler (refrigerant evaporator) to cool and dehumidify the air, then raise it to the target temperature, and then humidify to achieve the target temperature and humidity conditions. Since this was done by an air cooler, if the incoming air had to be cooled to below 0℃ using an air cooler, continuous operation would become impossible due to frost formation on the cooling fins, etc. The defrosting operation significantly disrupts the control of the target space, making it difficult to precisely control the humidity of the target space at temperatures below 0°C. In contrast, in the case of the method of the present application, even in such a low temperature range, when the operation enters a steady state and the target space reaches around the target value, the air entering the air cooler is transferred to the air cooler. Since the conditions are such that the dew point is reached just after cooling, almost no frost formation occurs. Therefore, humidity control can be achieved with extremely high precision when the dew point is below freezing, or when maintaining a target space at a temperature below freezing, and this can be maintained stably over a long period of time. be able to. A humidifier is almost not necessary when controlling humidity at sub-zero temperatures, and even when controlling humidity at higher room temperatures, it does not generate the large amount of drainage that conventional methods do, so it can be done with a small amount of humidification. There is an effect.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of an apparatus used to implement the method of the present invention. FIG. 2 is an explanatory diagram showing the structure of the refrigerant heater of FIG. 1. FIG. 3 is an explanatory diagram showing another embodiment of the refrigerant heater.

Claims (1)

[Claims] 1. A constant-temperature air supply machine equipped with a blower in an air flow path, and equipped with a refrigerant evaporator of a refrigerator as an air cooler and an air heater provided on the leeward side of the refrigerant evaporator, and the constant-temperature air supply machine. and a constant temperature and humidity chamber connected to form a series of air circulation channels, wherein a refrigerant heater is provided at an appropriate position in the refrigerant flow path from the refrigerant expander to the refrigerant evaporator of the refrigerator, The refrigerant heater is configured to be able to heat the refrigerant flowing into the refrigerant evaporator, and the refrigerant heater is operated so that the air passing through the refrigerant evaporator reaches the dew point temperature of the air having temperature and humidity conditions that are the target values of the constant temperature and humidity chamber. The constant temperature and humidity air is characterized in that the cooling capacity of the refrigerant evaporator is adjusted, and the air that has passed through the refrigerant evaporator is heated to the target temperature by an air heater and then supplied to the constant temperature and humidity room. supply method.