JPH058408Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement of a refrigerated constant temperature and humidity device for creating a low humidity environment for long-term preservation of plant seeds, etc.

Conventional technology Conventional constant temperature and humidity equipment uses a heating means such as an electric heater to heat air that has been dehumidified and cooled by an evaporator in a refrigeration cycle that is connected to a compressor, condenser, expansion valve, evaporator, etc., to a predetermined temperature. It is generally known that the device is configured to heat up to 100% and then blow air using a blowing fan.

However, when trying to obtain low humidity in such equipment (below 60% RH), the evaporator outlet air temperature is close to the dew point temperature, but in order to further reduce humidity, the evaporation pressure must be lowered to reach the dew point temperature. It becomes necessary to lower the In this case, the lower the evaporation temperature, the lower the cooling capacity of the refrigeration cycle. On the other hand, the evaporator inlet air temperature is also higher than the evaporation temperature.

As a result, the evaporator becomes overheated and cannot sufficiently dehumidify.

Therefore, to achieve low humidity, adsorbents such as LiCl are used to chemically absorb the moisture in the air, and then the dry air is adjusted to a predetermined temperature using a refrigeration cycle evaporator and electric heater to supply dry air into the warehouse. A method of supplying it is adopted.

Problems that the invention aims to solve However, in the case of devices using such conventional adsorbents, the water absorption capacity decreases after the adsorbent has absorbed enough water, so the adsorbent is heated to absorb moisture. need to be purged. Furthermore, it is necessary to use another adsorbent during purging, which inconveniently increases the size of the entire apparatus.

Furthermore, since it is structured to absorb moisture using the chemical reaction of the adsorbent, if it is used for a long period of time, the equipment containing the adsorbent and surrounding equipment will be damaged due to corrosion etc. There is also the disadvantage of a short life cycle.

In view of the drawbacks of the prior art, an object of the present invention is to provide an apparatus capable of creating a low-humidity environment using only a refrigeration cycle without using an adsorbent.

Means for solving the problems That is, the present invention provides a compressor, a condenser, an expansion valve,
In a device in which an evaporator of a refrigeration cycle, a blower for blowing air, and a heater for heating are installed in an intake duct, the evaporator and the evaporation pressure adjustment valve are connected in circulation, and the evaporation pressure adjustment valve is set in the control device. The low-humidity constant-temperature constant-temperature controller is configured to open and close based on the temperature and humidity set, and the blower is configured to operate to lower the rotation speed according to instructions from the control device when the evaporation temperature is set low. A humidification device achieves this objective.

In creating the low-humidity constant temperature and humidity device of the present invention, it is recommended to make the area of the evaporator wider than usual so that the temperature difference between the evaporation temperature of the evaporator and the outlet air temperature of the evaporator is small. It is also good to adopt an evaporation pressure regulating valve that can continuously widen or narrow the opening in order to change the evaporation temperature of the evaporator.

Furthermore, it is preferable to adopt an expansion valve whose opening degree can be adjusted so as not to cause a shortage of refrigerant supply when lowering the evaporation temperature.

Function: In the device according to the present invention, set temperature and humidity are input to the control device.

Then, based on the temperature and humidity, the control device
The dew point temperature is calculated, and the refrigeration cycle is instructed to adjust the opening degree of the evaporation pressure regulating valve so that the evaporation temperature becomes the dew point temperature of the set humidity.

The air sent from the blower is then dehumidified by the evaporator, lowering the absolute humidity.

Next, the air that has been dehumidified and cooled by the evaporator is heated by an electric heater and raised to a predetermined temperature. As a result, the relative humidity becomes a predetermined humidity, and the air is blown into a storage room such as a warehouse.

When the evaporation pressure regulating valve is throttled and the evaporation pressure is lowered, there is a risk that the cooling capacity of the refrigeration cycle will be exceeded. Therefore, in the device according to the present invention, the rotation speed of the blower is adjusted in conjunction with lowering the evaporation temperature. It acts to reduce the

Embodiment Hereinafter, the present invention will be explained in detail according to an embodiment shown in the drawings.

In the figure, 1 is an intake duct for introducing low-humidity constant-temperature air into a seed storage room such as a warehouse (not shown).Inside the duct, from the left are a blower 2, a compressor 3, a condenser 4, an expansion valve 5, The evaporator 6 and electric heater 9 of the refrigeration cycle are connected in circulation to the evaporator 6, the electronic evaporation pressure regulating valve 7, and the accumulator 8.
are placed in series with.

The opening degree of the evaporation pressure regulating valve 7 can be continuously adjusted by the operation of a drive circuit 10, and the blower 2 has a rotation speed controller 1.
The number of rotations can be increased or decreased based on instructions from 2.

These drive circuits 10 include an evaporation pressure regulator 14
be controlled by. That is, the drive circuit 10 is instructed to adjust the opening degree of the evaporation pressure regulating valve 7 based on the temperature difference between the temperature detected by the temperature detection means 15 provided near the air outlet of the evaporator 6 and the set evaporation temperature.

Reference numeral 16 denotes an overall control device, which calculates the evaporation temperature based on inputs to temperature and humidity input means, such as a temperature setting knob 18 and a humidity setting knob 19, and controls the evaporation pressure regulator 14 and rotation speed control, respectively. instruct the device 12.

Reference numeral 17 denotes a temperature detecting means installed near the air outlet of the electric heater 9. Based on the detection result of the detecting means 17, the control device 16 supplies electric power to the electric heater 9 to maintain the set temperature.

Specifically, when the temperature knob of the dual adjustment knob 20 is moved from high to low, the rotation speed knob is also simultaneously operated from high to low.

The operation of the apparatus according to the embodiment of the present invention in the configuration described above will be specifically explained.

When the set temperature is 10°C and the set humidity is 50%RH under conditions of air temperature 10°C and humidity 70%RH (conditions shown in Figure 3 A), the evaporation temperature of the evaporator is approximately 0°C and the control device 16 The rotation speed and evaporation temperature are given to each rotation speed controller 12 and evaporation pressure regulator 14 by calculating and operating the double knob 20.

Based on the given evaporation temperature of 0°C, the drive circuit 10
is operated to adjust the opening degree of the evaporation pressure regulating valve 7.

As a result, the refrigeration cycle operates to bring the evaporator 6 to 0°C.

As a result, the air blown from the blower 2 is cooled and dehumidified by the evaporator 6 (the state shown in FIG. 3B), and the temperature after being dehumidified is measured by the temperature detection means 15.
is detected, the opening degree of the evaporating pressure regulating valve 7 is adjusted by the evaporating pressure regulator 14 so that the temperature of the air exiting the evaporator 6 is always 0°C.

Since the saturated evaporation pressure at 0°C corresponds to approximately half of the saturated evaporation pressure at 10°C, the electric heater 9
If the air is heated to 10°C, air at the set temperature and humidity will be supplied (state shown in Figure 3C).

The rotational speed of the air blower 2 is configured so that the air volume decreases as the evaporation set temperature decreases, but the amount of heat Qi to be removed by the evaporator is Qi = (V/ν)・δ ₁ [Kcal/h ] V: Air volume [m ³ /h], ν: Specific volume [m ³ /Kg], δ ₁ : Enthalpy difference at evaporator inlet and outlet [kcal/
Kg], and by reducing V, Qi also decreases proportionally, so the evaporator can be operated without overheating.

Therefore, the adjustment can make the capacity of the evaporator linear in direct proportion to the evaporation temperature, as shown in FIG.

Effects As described above, the device according to the present invention can create relatively low-humidity air using only the refrigeration cycle, and can lengthen the life cycle of the device.

[Brief explanation of the drawing]

The figures show one embodiment of the device according to the present invention. Fig. 1 is a longitudinal sectional view showing the outline of the device, and Fig. 2 is a graph showing the temperature and humidity range that can be set for the device of the present invention and the conventional device. , FIG. 3 is an psychrometric diagram showing the dehumidification and heating process of the apparatus according to the present invention, and FIG. 4 is a graph showing the relationship between evaporation temperature and evaporator capacity. 1...Intake duct, 2...Air blower, 3
...Compressor, 4...Condenser, 5...Expansion valve, 6...
... Evaporator, 7 ... Evaporation pressure regulating valve, 8 ... Accumulator, 9 ... Electric heater, 10 ... Drive circuit, 12 ... Rotation speed controller, 14 ... Evaporation pressure controller, 15 ... Temperature detection Means, 16...control device, 18...temperature setting knob, 19...humidity setting knob, 20...double adjustment knob.

Claims (1)

[Scope of utility model registration request] In the device in which an evaporator of a refrigeration cycle is cyclically connected to a compressor, a condenser, an expansion valve, an evaporator, and an evaporation pressure regulating valve, a blower for blowing air, and a heater for heating are installed in an intake duct. The evaporation pressure regulating valve is configured to open and close based on the temperature and humidity set in the control device, and the blower operates to lower the rotation speed according to instructions from the control device when the evaporation temperature is set low. A low humidity constant temperature and humidity device.