JPH0427457B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a constant temperature and humidity device, and particularly to a constant temperature and humidity device that eliminates supercooling and reheating except when dehumidification of indoor air is required.

(Background technology) Figure 1 shows a conventional psychrometric diagram (diagram of changes in the state of air), where the horizontal axis is temperature, the vertical axis is absolute humidity (weight of moisture in 1 kg of air), and the diagonal curve is the saturation curve. (RH100%).

In conventional constant temperature and humidity devices, indoor air 1 is mixed with outside air 2 in the device to create (state 3 in Figure 1), which is then cooled and dehumidified to a constant temperature (dew point) using a cooling coil (state 1). From state 4 in the figure), it is heated again with a heater to a temperature corresponding to the indoor load (state 5 in Fig. 1) and then blown into the room. Therefore, the first
Between 4' and 5' on the horizontal axis (temperature) at the bottom of the figure, there was a loss due to cooling and reheating. In addition, 1,
4' and 5' indicate the air temperature of 1, 4, and 5, respectively;
x1, x2, and x3 indicate air humidity of 1, 2, and 3, respectively.

(Problem of the Invention) The present invention is intended to improve the above-mentioned drawbacks of the conventional technology, and an object of the present invention is to provide a constant temperature and humidity device that consumes less energy by controlling cooling and dehumidification using a computer.

(Structure and operation of the invention) FIG. 2 shows an psychrometric diagram according to the invention. Figure 3 shows a constant temperature and humidity device according to the present invention, where A is a constant temperature and humidity chamber, B is a constant temperature and humidity device, C is a cooling coil, E is a reheating coil, L is a humidifier, F is a fan, and H is a An indoor humidity sensor, T indicates an indoor temperature sensor, TC indicates a coil outlet temperature sensor, and M indicates a control device.

Dehumidification is absolutely necessary because the absolute humidity X2 at point 2, which represents the outside air in Figure 1, is higher than the indoor absolute humidity X1, and therefore the absolute humidity X3 of the mixed air 3 is also higher than the indoor absolute humidity X1. It is clear that this only occurs when the indoor relative humidity increases due to the generation of a large amount of moisture indoors.

When the temperature and relative humidity of outside air are lower than indoors, the absolute humidity is also low, and even if outside air is mixed, the absolute humidity will not increase, and even when little moisture is generated indoors, dehumidification is not necessary. Therefore, it is sufficient to set the air temperature at the outlet of coil C between 4 and 5 in FIG. This is set as 4".Also, even in summer, the first
As shown in the figure, when the amount of outside air is small, the amount of dehumidification may be small, so this can be explained using Fig. 2. An important point of this invention is to automatically control the temperature at this 4'' point using a microcomputer to save energy.

This control sends the numerical value from the indoor humidity sensor H shown in Fig. 3 to the control device M, and when the value moves beyond the desired humidity value, the air cooling temperature (second Rewrite the setting value of 4'' in the figure.This rewriting is done every fixed cycle.

Figure 4 shows the flow of the microcomputer program.

The desired relative humidity is set in memory A. At this time, in order to prevent frequent correction operations due to slight differences in humidity, it is preferable to take a very small value α (for example, α=1), so that A ₁ =A+α and A ₂ =A
-α is set in memory.

The indoor humidity measured by the humidity sensor H is converted into a digital value and then set in the memory B.

The microcomputer compares _A1 and _A2 with B, and if B> _A1 , lowers the set temperature T1 at the outlet of the cooling and dehumidifying means by a predetermined value ΔT (ΔT is, for example, 0.1° C.). on the other hand,
When A ₂ >B, the set temperature T1 is increased by ΔT. When A ₁ ≧B≧A ₂ , the set temperature T1 is not changed.

The above operation is repeated at regular intervals (for example, about 30 seconds to 5 minutes).

The set temperature T1 is generally higher than the dew point temperature, but since the cooling coil itself is sufficiently low temperature, the condensation is adjusted according to the set temperature T1.
Dehumidification is performed. Therefore, even when the outside air humidity is high, the desired indoor humidity can be obtained by dehumidifying.
Indoor humidity can be adjusted by adjusting the set temperature of the output of the cooling coil.

According to changes in the set cooling temperature, the amount of refrigerant or chilled water in the cooling coil is changed using general electric or electronic control, and the temperature at 4'' in Figure 2 (air temperature at the coil outlet) reaches the set cooling temperature. The cooling coils are controlled so that they are equal. If the indoor humidity is high, lower 4" to the left, that is, to the low temperature side, in FIG. The blowout temperature 5 is controlled by controlling the heating coil E by a temperature sensor T in accordance with changes in the room temperature. In addition, due to insufficient indoor humidity,
When the humidity of 5 is below the SHF line, the air of
Humidify until the temperature reaches (L in Figure 3). When the indoor humidity is not insufficient, the air from step 5 is blown out as is without humidification.

SHF (sensible heat ratio) is the value obtained by dividing the indoor sensible heat load by the total heat (sensible heat load + latent heat load). When the indoor evaporated moisture (latent heat load) is 0, SHF = 1, and SHF The line is horizontal.

If there is a lot of evaporated water, the SHF line will slope upward to the right.

The SHF value is unique to each room, and the slope of the SHF line is determined by the SHF value. Therefore, by drawing a straight line that passes through state point 1 of the air in the room and is parallel to the slope, the SHF line for that room can be obtained.

The air blown out on the SHF line receives a heat load inside the room and moves to the right, absorbing moisture in the room, increasing humidity and moving upward and to the right on the SHF line specific to that room.

As is clear from the above, the present invention controls the set value of the air cooling temperature with a microcomputer according to the indoor humidity, thereby omitting or minimizing the cooling and heating between 4 and 5 in Fig. 1 (conventional system). It is.

(Effect of the invention) While the conventional constant temperature and humidity system fixes the cooling coil outlet air temperature (4 in Figure 1), the present invention controls the cooling coil outlet air temperature using a microcomputer based on the indoor relative humidity. Since supercooling and reheating are omitted except when it is necessary to dehumidify the indoor air, the amount of cooling and reheating is extremely small.

According to estimates, energy savings can be achieved by 10% to 30% compared to conventional technology in the winter and intermediate seasons, and the same effect can be achieved in the summer when the outside humidity is low.

Further, according to the present invention, the amount of outside air taken in for ventilation necessary for human residences is not used at all for air conditioning, so there is an effect that ventilation is not affected by air conditioning.

[Brief explanation of drawings]

FIG. 1 is an psychrometric diagram according to the prior art, FIG. 2 is an psychrometric diagram according to the present invention, FIG. 3 is a block diagram of a constant temperature and humidity apparatus according to the present invention, and FIG. 4 is a flowchart of a microcomputer program.

Claims (1)

[Scope of Claims] 1. A constant temperature and humidity system having means for cooling and dehumidifying indoor air by mixing it with outside air, a heater for reheating the output thereof, and means for humidifying the output as necessary and blowing it into the room. In the apparatus, the set value (T1) of the temperature at the outlet of the cooling and dehumidifying means C is controlled at predetermined time intervals according to changes in the indoor humidity (H), and the heater is controlled according to the indoor temperature. A control device M equipped with a microcomputer is provided, and the control device M compares A and B with a memory A for setting the desired relative humidity and a memory B for setting the humidity measured by the indoor humidity sensor H. and when B is larger than A, the set value (T1) of the temperature at the outlet of the cooling and dehumidifying means C is lowered by a predetermined value, and when B is smaller than A, the set value (T1) is lowered by a predetermined value.
is increased by a predetermined value, and when B is equal to A, the set value (T1) is left unchanged, and according to the set value (T1), the temperature is detected by the temperature sensor TC provided at the outlet of the cooling and dehumidifying means C. A constant temperature and humidity device that controls the temperature so that it is equal to a set value (T1).