JPS5843344A - Control of cooling coil of air conditioning apparatus - Google Patents

Abstract

PURPOSE:To operate the titled apparatus in an energy saving manner by a method wherein in the case of the air conditioning apparatus utilizing the open air, the opening degree of a mixing damper adopted to introduce the mixture of the open air and the return air from an air conditioning chamber into an air conditioner is controlled in proportion to the enthalpy and the absolute humidity of the open air. CONSTITUTION:In the titled apparatus in which air in the air conditioner 4 provided with cooling, heating and humidifying coils 5-7 is blown out into the air conditioning chamber 9 by means of a blower 8, the mixing damper 3 for supplying the mixture of the open air and the return air from the air conditioning chamber to the air conditioner 4 is controlled such that when the enthalpy of the open air is higher than that of the air at the point where it is blown out into the air conditioning chamber 9 and the absolute humidity of the open air is higher than that of the air at that point, the quantity of intake of the open air is reduced to a minimum. Then the air mixture at the damper 3 heated up to the blowout point temperature after it is cooled and dehumidified to a point of intersection of the absolute humidity at the blowout point and a saturation line. On the other hand, when the above condition is reversed, the opening degree of the damper 3 is controlled to make the mixing ratio of the return air from the chamber 1 zero and the open air is dehumidified to the absolute humidity at the blowout point after it is cooled down to a point on a line of enthalpy including the blowout point.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling an R air conditioner that uses outside air, and particularly to a method for controlling a cooling coil when the enthalpy of outside air is greater than that at the blowout point.

FIG. 1 is an explanatory diagram of air conditions in a conventional method of controlling a cooling coil of an air conditioner. In an air conditioner equipped with a cooling coil, a heating coil, and a humidifying device, conventionally, outside air and part of the return air are mixed at a certain ratio, and then cooled or heated and humidified to create a blowout point into the conditioning room. I was getting it.

For this reason, if the enthalpy of outside air is higher than that at the blowout point to the air conditioning room, in Figure 1, part of the return air is
and outside air B are mixed at a constant ratio to obtain a state point C after mixing on a line connecting state points A and B. Furthermore, based on the indoor humidity signal, the room is cooled and dehumidified to the point where the absolute humidity line including the blowout point E intersects with the saturation line, and then heated to the blowout point E.

For this reason, the air conditioner was always controlled through a cooling and heating process to obtain the outlet point.Also, the enthalpy of the outside air was greater than that at the outlet point, and the absolute humidity of the outside air was lower than that at the outlet point. In this case, the outside air B' is mixed with part of the return air A to obtain the state point C', and the air is cooled, dehumidified, and heated from point C to the intersection of the absolute humidity line and the saturation line at the blowout point E. The blowing point E was obtained by humidifying as necessary.

For this reason, the mutually contradictory operations of cooling and heating are always performed.
・"Ne" 0 wasteful thoughts; 1:, :,, occurred 1" The purpose of the present invention is to eliminate as much as possible the waste of energy due to the contradictory operations of cooling and heating, which is a drawback of the prior art. The purpose of the present invention is to provide a cooling coil control method for an air conditioner.

This invention uses outside air whose enthalpy is P larger than that at the outlet point, and when the absolute humidity of the outside air is higher than that at the outlet point, the intake amount of outside air is set to the minimum, and the return air □ After mixing with a part of the outside air, it is cooled and dehumidified to the intersection of the absolute humidity line and the saturation line at the outlet point, and then heated to the outlet point. If the absolute humidity of the outside air is lower than that at the outlet point, the entire amount of outside air is After cooling to a point on the enthalpy line that includes the intake and outlet points, the absolute value of the outlet point! It controls the cooling coil to humidify the air to a certain degree.

FIG. 2 shows an explanatory diagram of air conditions in the cooling coil control method for an air conditioner according to the present invention.

FIG. 3 is a diagram showing a cooling coil control method for an air conditioner according to the present invention.

Air supply duct 1; return air duct 2, mixing chamber 3, air conditioner 4.1 coil 5, heating coil 6, humidification coil 7, blower 8, air conditioning room 9, exhaust fan 10, etc. This shows an air conditioning system consisting of:

In Fig. 2, if the enthalpy of the outside air is greater than that at the outlet point E into the air conditioning room and the absolute humidity of the outside air is higher than that at the outlet point E, the amount of outside air intake is minimized and the mixing damper 3 The state point C of the mixed air is obtained from the return air state point A and the outside air state point B, and the air is cooled from the zero point toward the intersection of the absolute humidity line and the saturation line at the outlet point. Perform dehumidification.

At this time, cooling and dehumidification is performed until the relative humidity reaches 100%.

It is further heated from point D to obtain a blowout point E into the air conditioning room.

In addition, in Figure 2, if the enthalpy of the outside air is greater than that at the outlet point E, and the absolute humidity of the outside air is lower than that at the outlet point E, the mixed amount of return air is set to zero and the entire amount of outside air is removed. Set the opening degree of the mixing damper 3 so that
Cool to point F. At this time, the relative humidity is not cooled to 100%. After this cooling, humidification is performed to the absolute humidity of the blowing point E.

As described above, the cooling coil 5 may perform only cooling or may perform cooling and dehumidification depending on the height relationship between the absolute humidity of the outside air and the absolute humidity of the outlet point.

In order to control this, the following phenomenon is used.

When outside air having an absolute humidity higher than the absolute humidity at the blowing point is taken in, the humidity in the air conditioning room increases. -Also, when outside air having an absolute humidity lower than the absolute humidity at the blowing point is taken in, the temperature of the air conditioning room mainly changes.

Utilizing this phenomenon, the dry bulb temperature and wet bulb temperature of the air conditioning room are detected by the dry bulb thermometer 14 and wet bulb thermometer 15, respectively, and the relative humidity converter 16 is used to detect the relative humidity. Convert to humidity.

The operation of the cooling coil is switched based on the deviation value between the relative humidity obtained by the dry bulb thermometer and wet bulb thermometer installed in the air conditioning room and the set relative humidity, or the deviation value between the dry bulb temperature and the set temperature. Prioritize and control the larger one.

The humidification control valve 12 is controlled to be fully closed during the cooling and dehumidification process. The enthalpy and absolute humidity of the outside air are calculated by the microcomputer 17 from the dry bulb temperature and wet bulb temperature.

The control device 18 controls the cooling control valve 13 of the cooling coil 5 and the humidification control valve 12 of the humidifying pump 1 of the humidifying coil 7.

In this invention, when the enthalpy of the outside air is larger than that at the blowout point and the absolute humidity of the outside air is lower than that at the blowout point, the entire amount of outside air is taken in, so the dehumidification process is omitted and cooling is performed. It can be only a process.

Therefore, in this case, the relative humidity is not cooled to 1.00%,
Because it only needs to be cooled halfway and then clouded, compared to the conventional method of cooling and reheating at 100% relative humidity.
Energy for supercooling and reheating is no longer required, resulting in energy savings of approximately 100,000 yen throughout the year.

In addition, the operation of the cooling coil can be performed as cooling/dehumidifying or □ depending on the relationship between the absolute humidity of the outside air and the air outlet point.

For control to switch to cooling only, the temperature of the air conditioning room, □
, , , □ o0 Garlic''' It is controlled by the tool □ -, so
Indoor temperature and humidity become stable.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of air conditions in a conventional method of controlling a cooling coil of an air conditioner, FIG. 2 is an explanatory diagram of air conditions in a method of controlling a cooling coil of an air conditioner according to the present invention, and FIG. FIG. 2 is a system diagram of a method for controlling a cooling coil of an air conditioner according to the present invention. l...Air supply duct 2...False air duct 3...
・Mixing damper 4... Air conditioner 5... Cooling coil 7... Humidifying coil 9... Air conditioning room 12... Humidification control valve 13... Cooling control valve
14...Dry bulb thermometer 15...Wet bulb thermometer 1
6... Relative humidity converter 17... Microcomputer 18... Control device. 1 1il, 62.1, ′□゛＼. Figure 1 ``ffi 51LL''

Claims (1)

[Claims] (1) In an air conditioner that uses outside air where the enthalpy of the outside air is greater than that at the outlet point, (a) when the enthalpy of the outside air is greater than that at the outlet point and the absolute humidity of the outside air is higher than that at the outlet point; In this method, the amount of outside air taken in is set to the minimum and mixed with a portion of the return air, and then the mixed gas is cooled and dehumidified to the intersection of the absolute humidity at the blowout point and the saturation line, and then heated to the blowout point. (b) If the enthalpy of the outside air is greater than that at the blowout point and the absolute humidity of the outside air is lower than that at the blowout point, set to full outside air intake and transfer the outside air to a point on the enthalpy line that includes the blowout point. 1. A cooling coil control method for an air conditioner, characterized in that the cooling coil is cooled down to a temperature of 100 degrees, and then humidified to the absolute humidity of a Suita point. (2. In claim 1, switching between cooling only or cooling and dehumidification of the cooling coil is based on relative humidity obtained from signals from a dry bulb thermometer and a wet bulb thermometer installed in the air conditioning room. A method of controlling a cooling coil of an air conditioner in which the larger of the two is given priority and controlled between the deviation value between the temperature and the set relative humidity, or the deviation value between the dry bulb temperature and the set soft bulb temperature.