JP2004028476A - Air conditioner system having coil freeze proofing function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent freezing of a cold/hot water coil, to allow mounting to an existing air conditioner system, and to reduce cost such as a facility, even when flow rate of hot water of an air conditioner is reduced for temperature adjustment in a cold season, or even when an operation of the air conditioner is stopped. <P>SOLUTION: The air conditioner 4 comprising a coil unit 5 having the cold/hot water coil 5A and a blower 6 is connected to a heat source apparatus 1 through a cold/hot water supply pipe 2 and a cold/hot water return pipe 8. A flow rate control valve 13 of the cold/hot water supply pipe 2 controls the flow rate of the hot water in response of a signal of a temperature sensor 12. A bypass pipe 22 is connected between the cold/hot water supply pipe 2 and the cold/hot water return pipe 8 to form a bypass circuit 21 including the cold/hot water coil 5A. Even when the flow rate control valve 13 is throttled with the signal of the temperature sensor 12, the hot water is circulated to the bypass circuit 21 by a circulating pump 24 to make a certain amount of hot water flow to the cold/hot water coil 5A to prevent freezing. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner system having a coil freezing prevention function that prevents a coil of an air conditioner for an air conditioner, that is, a coil of an outside air intake air heater from freezing in a cold region.
[0002]
[Prior art]
FIG. 2 shows a conventional air conditioner system. In the drawing, 1 is a heat source device such as a boiler or a cold / hot water generator, 2 is a cold / hot water supply pipe connected to the discharge side of the heat source device 1 via a supply header 3, and 4 is a cold / hot water supply tube. The air conditioner 4 generates warm air by warming the outside air with hot water supplied from the heat source device 1. The air conditioner 4 includes a cold water coil 5A, a hot water coil, a cold water coil, and a cooling water coil (see FIG. (Not shown) in a casing 5B, and a blower 6 for sending out the warm air generated by the coil unit 5 to the indoor side. The wind is distributed through the ventilation duct 7 to the rooms A to C.
[0003]
Reference numeral 8 denotes a cold / hot water return pipe for returning the cold / hot water heat-exchanged with the outside air introduced by the cold / hot water coil 5A to the heat source device 1, and the cold / hot water return tube 8 is connected to the heat source device 1 via the return header 9. . Reference numeral 10 denotes a relief pipe connected between the return header 9 and the supply header 3. The relief pipe 10 is provided with a safety relief valve 11, and a flow rate control valve 13, which will be described later, is closed to supply cold and hot water. When the pressure in the pipe 2 rises to a certain value, the hot water from the heat source device 1 is refluxed to prevent the evaporator from freezing when the cold / hot water generator generates cold water, and to prevent its pressurization.
[0004]
Reference numeral 12 denotes a temperature sensor provided in the blower duct 7. The temperature sensor 12 detects whether or not the warm air sent from the blower duct 7 to the indoors A to C is at a set temperature. Reference numeral 13 denotes an electric motor type flow control valve provided in the cold / hot water supply pipe 2. The flow control valve 13 increases or decreases the flow rate of hot water supplied to the air conditioner 4 in accordance with a temperature signal from the temperature sensor 12. .
[0005]
A motor damper 14 is provided in an outside air duct 15 for introducing outside air into the air conditioner 4 and shuts off the outside air as necessary. The motor damper 14 interlocks with the blower 6 when the air conditioner 4 stops at night. And shuts off the outside air duct 15.
[0006]
The air conditioner system of the related art has the above-described configuration, supplies hot water from the heat source device 1 to the air conditioner 4 through the cold / hot water supply pipe 2, and heats the outside air to generate hot air at a desired temperature. 6, the air is sent from the ventilation duct 7 to each of the indoor air-rooms to maintain the indoor air-room at a predetermined temperature. However, in the course of this operation, if the temperature in the air duct 7 satisfies the set temperature, for example, 20 ° C. or more, the flow control valve 13 is operated by the signal from the temperature sensor 12 to the cold / hot water coil 5A. Since the flow rate of the hot water is decreased, the flow rate of the hot water in the cold / hot water coil 5A becomes non-uniform, causing a shortage of the flow rate, resulting in a phenomenon that the flow velocity becomes slow. In this state, a low-temperature outside air hits the inlet face of the cold / hot water coil 5A, causing a problem that the hot water is locally frozen at a low flow rate, and the inside of the cold / hot water coil 5A is closed to cause malfunction of the air conditioner. Or rupture of piping.
[0007]
In particular, in a situation where the outside air temperature is lower than −15 ° C. in a cold region, the freezing phenomenon of the cold / hot water coil 5A often becomes a problem. Therefore, for example, in Japanese Patent Application Laid-Open No. 2001-182968, a pre-coil unit 11A and a main coil unit 11B are installed in an air conditioner 10 to which hot water is supplied from a heat source device, and hot water supplied from an upper portion of an inlet coil header is supplied to an outlet coil. By sending the water from the lower part of the header, it is cooled, the temperature is low, the hot water having a large specific gravity is pushed out to prevent the coil unit 11 from freezing, and the temperature of the hot water sent from the outlet side coil header becomes 4 ° C. By controlling the amount of hot water supplied to the pre-coil unit 11A by the control valve CVa, hot water having a specific gravity close to the freezing temperature is sequentially sent out from the outlet-side coil header to prevent freezing of the pre-coil unit 11A. A method for preventing a coil from freezing in an air conditioner is disclosed.
[0008]
Japanese Patent No. 2926708 discloses a configuration in which a plurality of meandering heat medium flow tubes 6 are inserted into a large number of plate fins 3 and a plurality of first headers 4 and one second header 5 are connected thereto. A heat exchange coil for preventing freezing is disclosed in which heat of the heat medium is transmitted to the entire area of the coil including the heat medium flow pipe 6 of the first header 4 that is not circulated through the plate fin group. I have.
[0009]
[Problems to be solved by the invention]
However, the technology of Japanese Patent Application Laid-Open No. 2001-182968 described above is an air conditioner 10 having a configuration in which a pre-coil unit 11A and a main coil unit 11B are installed, and the technology of Japanese Patent No. 2926708 also has a specially configured heat exchange for preventing freezing. It is a coil and does not solve the problem of coil freezing in an existing air conditioner, and has the drawback that it cannot be incorporated into an existing air conditioner system, and therefore has the problem of high costs.
[0010]
The present invention has been made in view of the above-described drawbacks of the related art. Even when the flow rate of hot water of the air conditioner is reduced for temperature control in a cold season, or when the air conditioner is stopped, the present invention provides a coil. Freezing can be prevented. It is another object of the present invention to provide an air conditioner system having a coil freezing prevention function that can solve the problem of coil freezing by assembling it with an existing air conditioner, thereby reducing the cost for that purpose.
[0011]
[Means for Solving the Problems]
Means of the present invention configured to solve the above-described problem is to generate warm air by heating the outside air with hot water supplied from a heat source device through a cold / hot water supply pipe, and the discharged cold / hot water is A coil unit including a cold / hot water coil that returns to the heat source device through a cold / hot water return pipe, a blower that sends out temperature-controlled air generated by the coil unit to the indoor side, and a blower that is provided in the cold / hot water supply pipe. A flow rate control valve for controlling the flow rate of hot water to the cold / hot water coil, and operates the flow rate control valve by a signal from a temperature sensor that detects whether or not the temperature-regulated air blown into the room by the blower is at a set temperature. In the air conditioner, a bypass pipe having a check valve is connected between the cold / hot water return pipe and the cold / hot water supply pipe at a position downstream of the flow rate control valve, thereby forming the cold / hot water coil. Ba containing A pass circuit is formed, a circulating pump is provided in the cold / hot water supply pipe located downstream of the bypass pipe, and even when the opening of the flow control valve decreases based on a temperature signal from the temperature sensor. The circulating pump circulates a predetermined amount of hot water through the cold / hot water coil to prevent the cold / hot water coil from freezing.
[0012]
An airflow control member for shutting off outside air is provided in an outside air duct for introducing outside air to the coil unit, and a freezing prevention temperature sensor and a coil heater for heating the cold / hot water coil are provided on the coil unit side, respectively. When the operation of the machine is stopped, the temperature of the outside air slightly entering from the air flow control member in the outside air cutoff state is detected by the antifreezing temperature sensor, and the circulation pump and the coil are detected based on the outside air temperature signal of the antifreezing temperature sensor. By operating the heater, hot water may be circulated through the bypass circuit to heat the cold / hot water coil.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, the same components as those of the prior art shown in FIG. 2 described above are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 1, reference numeral 21 denotes a bypass circuit including the cold / hot water coil 5A of the coil unit 5. Reference numeral 22 denotes a bypass pipe constituting the bypass circuit 21. The bypass pipe 22 has one end 22A connected to the cold / hot water return pipe 8, and the other end 22B located downstream of the flow control valve 13, and has a cold / hot water supply pipe. 2 and a check valve 23 is provided in the middle of the bypass pipe 22. Reference numeral 24 denotes a circulating pump located downstream of the bypass pipe 22 and provided in the cold / hot water supply pipe 2. The circulating pump 24 is constantly driven while the air conditioner 4 is operating, and a constant amount of hot water flows through the cold / hot water coil 5 </ b> A. And circulate.
[0014]
Reference numeral 25 denotes an anti-freezing temperature sensor provided in the coil unit 5. The anti-freezing temperature sensor 25 is provided when the operation of the air conditioner 4 is stopped and the outside air entering the air conditioner 4 from the outside air duct 15 blocked by the motor damper 14. This is to measure the temperature. Reference numeral 26 denotes a coil heater which is provided in the coil unit 5 and heats the cold / hot water coil 5A. The coil heater 26 and the circulation pump 24 are started based on a signal from the freeze prevention temperature sensor 25 to bypass hot water. The fluid is circulated in the circuit 21.
[0015]
This embodiment has the above-described configuration, and supplies hot water from the heat source device 1 to the air conditioner 4 via the hot water supply pipe 2, and heats the outside air to generate hot air generated at a desired temperature by the blower 6. The basic operation of sending the air from the duct 7 to each of the indoor rooms 1 to 3 to maintain the indoor rooms 1 to 3 at a predetermined temperature is not different from the conventional technology.
[0016]
Then, when the temperature in the air duct 7 satisfies the room temperature set temperature, for example, 20 ° C. or higher, the flow control valve 13 is operated by a signal from the temperature sensor 12 to reduce the flow of hot water to the coil unit 5. As a result, the flow rate of the hot water in the cold / hot water coil 5A becomes non-uniform, causing a shortage of the flow rate. Therefore, in the present embodiment, even when the flow rate control valve 13 is throttled and the flow rate of hot water to the cold / hot water coil 5A decreases, hot water is circulated to the bypass circuit 21 by the circulation pump 24, and the cold / hot water supply pipe 2 The hot and cold water returned from the bypass circuit 21 is mixed with the hot and cold water supplied from the heat source device 1 and mixed with the cold and hot water supply pipe 2 at the other end 22B of the bypass pipe 22 to supply a certain amount of hot water to the cold and hot water coil 5A. The maintenance prevents the cold / hot water coil 5A from freezing due to a decrease in the flow rate of the hot water.
[0017]
In addition, the air conditioner 4 is stopped during the winter night when the outside air temperature drops significantly, and the motor damper 14 cuts off the space between the outside air duct 15 and the air conditioner 4, but enters the outside air duct 15 from the gap of the motor damper 14. The phenomenon that outside air freezes the coil unit 5 occurs. Therefore, in the present embodiment, the freezing prevention temperature sensor 25 operates according to the temperature of the invading outside air to turn on the coil heating heater 26 such as an electric heater, and also starts the circulation pump 24 to switch the cold / hot water coil 5A. By circulating and flowing hot water through the bypass circuit 21 including the same, the freezing of the cold / hot water coil 5A is prevented.
[0018]
Although the motor damper 14 is used as the airflow control member in the present embodiment, a driving louver may be used instead of the motor damper 14.
[0019]
【The invention's effect】
The present invention has the following advantages because it is configured as described in detail above.
(1) A bypass circuit having a configuration including an air conditioner is provided in an air conditioner system, and even when the flow rate of hot water decreases due to temperature adjustment, hot water is circulated through the bypass circuit to maintain a constant flow rate of hot water in the cold / hot water coil. Thus, it is possible to prevent the coil of the air conditioner from freezing.
(2) Even when the outside air is shut off by the airflow control member when the operation of the air conditioner is stopped, the coil may be frozen depending on the temperature of the invading outside air. Since the warming water is circulated and flown to the bypass circuit by starting the circulation pump at the same time as starting, the freezing of the coil of the air conditioner can be reliably prevented.
(3) The coil can be prevented from freezing simply by incorporating a bypass circuit, a circulating pump, a freezing prevention temperature sensor and a coil heater into an existing air conditioner, so there is no need to procure a dedicated air conditioner and equipment costs. Are also inexpensive.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an air conditioner system having a coil freezing prevention function according to an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of an air conditioner system according to the related art.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 heat source device 2 cold / hot water supply pipe 4 air conditioner 5 coil unit 5A cold / hot water coil 6 blower 8 cold / hot water return pipe 12 temperature sensor 13 flow control valve 14 motor damper 15 outside air duct 21 bypass circuit 22 bypass pipe 23 check valve 24 circulation pump 25 Freezing prevention temperature sensor 26 Coil heating heater

Claims (2)

A hot / cold water coil is generated by heating the outside air with hot water supplied from a heat source device via a cold / hot water supply pipe to generate hot air, and the discharged cold / hot water is returned to the heat source device via a cold / hot water return pipe. A coil unit, a blower that sends out the temperature-controlled air generated by the coil unit to the indoor side, and a flow control valve that is provided in the cold / hot water supply pipe and controls a hot water flow rate to the cold / hot water coil, In an air conditioner in which the flow control valve is operated by a signal from a temperature sensor that detects whether or not temperature-controlled air blown into the room by the blower is a set temperature, the bypass pipe having a check valve is cooled to a low temperature. By connecting between the water return pipe and the cold / hot water supply pipe located downstream of the flow control valve, a bypass circuit including the cold / hot water coil is formed, and the bypass circuit is located downstream of the bypass pipe. Before A circulating pump is provided in the cold / hot water supply pipe, and even when the opening degree of the flow rate control valve decreases based on a temperature signal from the temperature sensor, a constant amount of hot water is circulated through the cold / hot water coil by the circulating pump. An air conditioner system having a coil freezing prevention function, wherein the cold / hot water coil is prevented from freezing. An airflow control member that shuts off outside air is provided in an outside air duct that introduces outside air into the coil unit, and a freeze prevention temperature sensor and a coil heater that heats the cold / hot water coil are provided on the coil unit side, respectively. When the operation is stopped, the temperature of the outside air slightly entering from the air flow control member in the outside air cutoff state is detected by the antifreezing temperature sensor, and the circulation pump and the coil heater are detected based on the outside air temperature signal of the antifreezing temperature sensor. The air conditioner system with a coil freezing prevention function according to claim 1, wherein by operating the air conditioner, hot water is circulated through the bypass circuit to heat the cold / hot water coil.

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