JPH0674915B2 - Ventilation and air conditioning equipment - Google Patents

Description

Description: [Object of the Invention] (Industrial field of application) [0001] The present invention relates to a ventilation air conditioning equipment, and particularly to a ventilation air conditioning equipment suitable for ensuring the soundness of a heat exchanger for adjusting the temperature of the outside air. Regarding

(Prior Art) FIG. 2 is a system diagram showing a conventional ventilation and air conditioning equipment applied to a building of a nuclear power plant.

When the air supply fan 1 is operated, outside air flows into the air supply casing 5 through the outside air louver 3. The outside air that has flowed into the air supply casing 5 has its dust removed by the air supply filter 7, and its temperature is adjusted by the cold / hot water coil 9 as a heat exchanger. The cold / hot water coil 9 is provided so that hot water can be passed as a working fluid during the heating operation in winter and cold water can be passed as a working fluid during the cooling operation described below. The figure shows the case where hot water is passed.

The outside air whose temperature is adjusted by the cold / hot water coil 9, for example, the outside air warmed during the heating operation, is blown to each room through the air supply fan 1 and the duct 11. During heating operation, the temperature of the air (outside air) flowing in the duct is measured by an outside air thermometer 13, and the temperature is adjusted by a temperature adjusting valve 19 so as to maintain a constant temperature. The temperature control valve 19 includes a temperature controller 15 connected to an outside air thermometer 13 and an electric / pressure converter.
Hot water supply system 21 that is operated by 17 and is a working fluid supply system
The flow rate of the hot water guided from the cold water to the hot and cold water coil 9 is controlled.

(Problems to be solved by the invention) However, during heating operation, when the outside air is lower than expected, or when the outside air thermometer 13, the temperature controller 15, the air / pressure converter 17 or the temperature control valve 19 fails or the hot water supply system twenty one
When the hot water supply amount is remarkably reduced due to the malfunction of the hot water, the hot water is frozen in the cold and hot water coil 9,
May be damaged.

The present invention has been made in consideration of the above facts,
An object of the present invention is to provide a ventilation and air conditioning equipment capable of preventing the working fluid flowing in the heat exchanger from freezing during heating operation, ensuring the soundness of the heat exchanger, and improving the reliability of the equipment.

[Structure of Invention]

(Means for Solving the Problems) The present invention relates to a ventilation and air conditioning facility for controlling the temperature of the outside air into a room by adjusting the temperature of the outside air with a heat exchanger connected to a working fluid supply system in which a working fluid controlled to a predetermined temperature flows. At the outlet of the heat exchanger, temperature detecting means for detecting the temperature of the working fluid flowing through the outlet is provided, and the heat exchanger is provided with a heat detecting means which is different from the working fluid and prevents freezing of the heat exchanger. A heat medium introducing pipe for guiding the medium to the heat exchanger is connected, and when the temperature of the working fluid detected by the temperature detecting means is below a predetermined value, the operation is opened to transfer the heat medium from the heat medium introducing pipe to the heat exchanger. A control valve for guiding is provided in the heat medium introducing pipe.

(Operation) Therefore, the ventilation and air conditioning equipment according to the present invention can maintain the temperature of the working fluid flowing in the heat exchanger at a predetermined temperature or more during the heating operation in which the outside air is heated by the heat exchanger and introduced into the room. . As a result, it is possible to prevent the heat exchanger from being damaged due to the volume expansion of the working fluid due to the temperature decrease.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing the periphery of a cold / hot water coil in an embodiment of the ventilation air conditioning equipment according to the present invention.

In this one embodiment, the antifreezing device is installed in the hot and cold water coil, and other points are the same as the conventional example. Therefore, the same parts as the conventional ones will be described with the same reference numerals. Omit it.

The hot and cold water coil 9 includes an inlet header pipe 23 and an outlet header pipe.
A plurality of coil tubes 27 that meander between 25
And a plurality of coil fins 29 fixed to the coil tube 27, and the coil fins 29 increase the heat transfer area. The inlet header pipe 23 or the outlet header pipe 25 is connected to the hot water supply system 21 via an inlet nozzle 31 or an outlet nozzle 33, respectively. Therefore, during the heating operation, the hot water from the hot water supply system 21 is introduced into the inlet header pipe 23 through the inlet nozzle 31, and the hot water introduced into the inlet header pipe 23 passes through the plurality of coil tubes 27. In the meantime, heat is radiated from the coil fin 29 to the outside air, cooled, reaches the outlet header pipe 25, and is returned to the hot water supply system 21 again. Thus, during the heating operation, the outside air is heated to a constant temperature by the heat radiation from the coil fins 29.

An antifreezing device 35 is installed on the cold / hot water coil 9. In the antifreezing device 35, a hot water thermometer 37 is attached to the outlet header pipe 25, a steam introducing pipe 39 as a heat medium introducing pipe is connected to the inlet header pipe 23, and an air operated valve 41 is arranged in the vapor introducing pipe 39. It was set up.

The steam introduction pipe 39 guides steam as a heat medium different from the working fluid into the inlet header pipe 23. Also, air operated valve
41 is connected to a solenoid valve 45 arranged in the air supply system 43,
It operates by the air pressure from the air supply system 43. Air operated valve
By the opening operation of 41, steam is supplied from the steam introducing pipe 39 into the inlet header pipe 23, and by the closing operation of the air operated valve 41, the supply of the steam is shut off.

The operation of the solenoid valve 45 is electrically connected to this solenoid valve 45,
And by a temperature switch 47 which is also connected to the hot water thermometer 37. That is, the temperature of the hot water flowing in the outlet header pipe 25 is measured by the hot water thermometer 37, and the temperature switch 47 detects this when the hot water temperature reaches a predetermined temperature, for example, about 15 ° C. or less, and the electromagnetic Activate valve 45,
The air operated valve 41 is opened. The hot water thermometer and the temperature switch 47 are referred to as temperature detecting means.

Therefore, in this embodiment, when the hot water that warms the outside air during the heating operation returns to the outlet header pipe 25, if the hot water temperature is about 15 ° C. or lower, the hot water temperature system 37 and the temperature switch 47 are When this is detected, the air operated valve 41 is opened via the solenoid valve 45. As a result, steam flows from the steam introduction pipe 39 into the inlet header pipe 23, and the inlet header pipe 23,
The temperature of the hot water flowing in the coil tube 27 and the outlet header pipe 25 is raised, and the freezing of the hot water can be prevented. Therefore, it is possible to prevent the coil tube 27 and the outlet header tube 25 from being damaged due to volume expansion due to freezing, maintain the soundness of the cold / hot water coil 9, and improve the reliability of the ventilation and air conditioning equipment. it can.

Next, another embodiment will be described.

In the other embodiments, the same parts as those in the above embodiment are designated by the same reference numerals. In this other embodiment, the steam inlet pipe 39 in the above embodiment is not the inlet header pipe 23 but the outlet header pipe 25.
And the coil tube 27 has a double tube structure. Then, the steam from the steam introducing pipe 39 is
The coil tube 27 is provided so as to heat the hot water flowing inside the double tube and flowing outside the double tube.

According to such another embodiment, when the hot water temperature in the outlet header pipe 25 becomes equal to or lower than the predetermined temperature, the steam is guided to the downstream side of the coil tube 27 having a low temperature and the outlet header pipe 25. It is possible to directly heat a place where there is a high possibility of freezing, and it is possible to improve responsiveness as compared with the above-mentioned embodiment.

In the above embodiment, the cold / hot water coil 9 is provided with an antifreezing device 35.
However, the antifreezing device 35 may be applied to the steam heating coil. Further, in the above-mentioned embodiment, the ventilation air conditioning equipment installed in the building of the nuclear power plant is explained, but any ventilation air conditioning equipment of the total ventilation type can be applied.

[Advantages of the Invention] As described above, according to the ventilation and air conditioning equipment of the present invention,
When the working fluid flowing through the outlet of the heat exchanger has a temperature equal to or lower than a predetermined temperature, the temperature detecting means detects this, and since the heat medium is introduced from the heat medium introducing pipe into the steam heat exchanger, The temperature of the working fluid flowing in the heat exchanger during heating operation can be maintained at or above a predetermined temperature, and as a result, the working fluid can be prevented from freezing and the heat exchanger can be kept sound, thus ensuring the reliability of the equipment. Can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the periphery of a cold / hot water coil in an embodiment of a ventilation air conditioning system according to the present invention, and FIG. 2 is a system diagram showing a conventional ventilation air conditioning system applied to a building of a nuclear power plant. . 1 ... Air supply fan, 9 ... Cold / hot water coil, 23 ... Inlet header pipe, 25 ... Outlet header pipe, 27 ... Coil tube,
35: Antifreeze device, 37: Hot water thermometer, 39: Steam inlet pipe, 47: Temperature switch.

Claims (2)

[Claims] 1. A ventilating and air-conditioning system for controlling the temperature of outside air into a room by means of a heat exchanger connected to a working fluid supply system through which a working fluid controlled to a predetermined temperature flows, and at the outlet of the heat exchanger. Is provided with temperature detecting means for detecting the temperature of the working fluid flowing through the outlet portion, and a heat medium which is different from the working fluid and which prevents the heat exchanger from freezing is introduced into the heat exchanger. A control valve that connects the introduction pipe and opens when the temperature of the working fluid detected by the temperature detecting means is below a predetermined value and guides the heat medium from the heat medium introduction pipe to the heat exchanger is the heat medium introduction pipe. Ventilation and air-conditioning equipment characterized by being installed in. 2. The ventilation according to claim 1, wherein the heat exchanger is a cold / hot water coil, and the heat medium introducing pipe is a steam introducing pipe for guiding steam as a heat medium to the cold / hot water coil. Air conditioning equipment.