JP3243729B2 - Central heat source type air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a central heat source type air conditioner suitably used for buildings such as office buildings.

[0002]

2. Description of the Related Art A central heat source type air conditioner is a system in which cold water or hot water is switched and supplied to an air conditioner installed on each floor of a building from a central heat source device every season. In this method, when a system to be supplied to a plurality of rooms is taken out from one air conditioner on each floor, and the room temperature is controlled according to the indoor load fluctuation of each system, the air conditioner is configured by the conventional technology. Cooling or heating coil
The amount of air controlled to the target temperature by cooling or heating every season is changed for each system, or the air controlled to the target temperature by the coil and the air bypassing the coil are mixed according to the indoor load fluctuation. A system in which the ratio is supplied while changing is adopted.

[0003]

However, in the above-mentioned conventional method, there is a problem that high-quality temperature control is required due to the necessity of performing the temperature control by proportional control, and as a result, equipment cost is increased. I have. Further, when the production of cold water and hot water is switched and supplied in each season, if a cooling request system and a heating request system simultaneously appear in the supply range of one air conditioner in winter, the temperature control of the cooling request system is performed. It became impossible, the room temperature was gradually increased, and energy saving operation by heat recovery operation was impossible.

The present invention solves the above-mentioned conventional problems, and sets the temperature of cold and hot water flowing from a central heat source device to a cold and hot water coil to a higher temperature in accordance with the outside air condition. By supplying the refrigerant to the evaporator for each air conditioning zone by ON / OFF control based on the signal from, the temperature control can be simplified and the energy saving effect by the heat recovery operation can be expected. An object of the present invention is to provide a central heat source type air conditioner that eliminates the need for operation of a central heat source device during a light load operation in the interim period, and that can freely use an evaporator for an air conditioning zone for cooling during heating. It is assumed that.

[0005]

For this purpose, the central heat source type air conditioner of the present invention comprises an air conditioner 1 installed on each floor of a building and a central heat source device 5 for circulating cold and hot water through each air conditioner 1. And a plurality of air conditioning zones 9 connected to the air conditioner 1
A temperature sensor 12 disposed in each air conditioning zone 9, a cold / hot water coil 15 disposed in the air conditioner 1, an evaporator 25 disposed for each air conditioning zone 9,
5, a blower fan 16 that circulates through each air conditioning zone 9 in the order of the evaporators 25, a system-specific temperature adjusting heat source device 19 that is connected to each evaporator 25 via a refrigerant supply on-off valve 23, and a central heat source device 5. A cold / hot water pump 6 for circulating the produced cold / hot water through the cold / hot water coil 15 and the heat source unit 19 for temperature adjustment for each system; and setting the cold / hot water temperature of the cold / hot water coil 15 to a higher temperature in accordance with the outside air condition. The on / off control based on the signal from the temperature sensor 12 in each air conditioning zone 9 opens and closes the refrigerant supply on-off valve 23 to supply the refrigerant to each evaporator 25. Note that the numbers added to the above configuration are compared with the drawings to facilitate understanding of the present invention, and the configuration of the present invention is not limited by this.

[0006]

According to the present invention, the supplied air is cooled or heated in a chilled / hot water coil with chilled / hot water of a higher temperature set in advance in any system according to the outside air condition, and then the temperature is adjusted for each system. After being cooled by the evaporator, it is supplied to each air conditioning zone. Refrigerant supply to each evaporator is performed by opening and closing a refrigerant supply opening / closing valve by on / off control based on a signal from a temperature sensor in each air conditioning zone. In addition, when the over-hour operation during cooling, the light load operation in the interim period, and the use of the system-specific temperature control heat source unit as the cooling heat source unit, the heat source unit of the central heat source device is stopped, and the system-specific temperature control heat source is used. The exhaust heat of the machine is radiated to the cooling water on the cooling tower side of the central heat source device to enable operation of the system-specific temperature adjusting heat source device.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is an overall configuration diagram showing one embodiment of a central heat source type air conditioner of the present invention. An air conditioner 1 according to the present invention is installed on each floor of a building, and each air conditioner 1 is provided with a cold / hot water supply pipe 2, It is connected to a central heat source device 5 via a cold / hot water return pipe 3 and an outside air supply duct 4.

FIG. 3 is a block diagram showing the relationship between the central heat source device 5 and the air conditioner 1 showing one embodiment of the central heat source type air conditioner of the present invention. The cold / hot water supply pipe 2 includes a pump 6 and a heat exchanger. It is connected to the central heat source device 5 via the vessel 7. The outside air is sucked by the blower 8 and cooled or heated by the heat exchanger 7, and then supplied to the air conditioner 1 through the outside air supply duct 4. The heat exchanger 7 is used as a heat source for cooling and dehumidifying or heating and humidifying the outside air to be taken in, and plays a role of a humidity controller for adjusting the humidity of the outside air. A vessel may be provided.

The cold / hot water produced by the central heat source device 5 is sent to the air conditioner 1 via the cold / hot water supply pipe 2 and then returned to the central heat source device 5 via the cold / hot water return pipe 3. Air conditioner 1
A plurality of air conditioning zones 9 having different heat loads are connected via an air supply duct 10 and a return air duct 11. The air-conditioning zones 9 are partitioned rooms or specific areas to be air-conditioned.
Are arranged.

FIG. 1 shows a central heat source type air conditioner of the present invention.
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a configuration diagram of an air conditioner 1 installed on each floor according to an embodiment. The air conditioner 1 basically includes a casing 13, a cold / hot water coil 15 connected to the central heat source device 5, a plurality of blower fans 16, a filter 17, and a system-specific temperature adjusting heat source device 19. Heat source unit 19 for temperature adjustment by system
Has a compressor 20, a condenser 21, and a refrigerant liquid reservoir 22, and a plurality of refrigerant supply opening / closing valves 23, an expansion valve 24, and an evaporator 25 are connected in parallel to these pipes. Each evaporator 25
Is disposed downstream of the cold / hot water coil 15. At a position facing each evaporator 25 of the casing 13, an air supply duct 10 that supplies air-conditioned air to the air-conditioning zones 9 of the plurality of systems described with reference to FIG. 3 is connected.

The cold / hot water supply pipe 2 of the central heat source device 5 is connected to the cold / hot water return pipe 3 via the bypass switching valve 26, the cold / hot water coil 15, and the condenser 21. The bypass switching valve 26 is a three-way valve that allows cold and hot water to bypass the cold and hot water coil 15, and is configured so that the cold and hot water that has exited the cold and hot water coil 15 exchanges heat with the condenser 21. .

FIG. 4 is a configuration diagram of a central heat source device 5 showing one embodiment of the central heat source type air conditioner of the present invention. Absorption type cold / hot water generator 30 as a heat source device, and absorption type cold / hot water generator 30
A cooling tower 31 and a cooling water pump 32 for circulating cooling water during cooling, a cold and hot water pump 6 for circulating cold and hot water from the absorption type cold and hot water generator 30 to the air conditioner 1,
A heat exchanger 34 for exchanging heat between the cooling water and the cold / hot water;
The switching valve 35 for the cooling water to bypass the heat exchanger 34 and the cold / hot water of the cold / hot water return pipe 3 are supplied directly to the cold / hot water pump 6 to control the cold / hot water temperature of the cold / hot water supply pipe 2. And a temperature control valve 36 for the purpose. In addition, as a heat source of the absorption-type cold / hot water generator 30, gas, oil, or steam is adopted.

Next, the operation control method of the present invention having the above-described configuration will be described with reference to FIG. FIG. 5 is a diagram for explaining an example of the control method of the present invention. In the control, the water supply temperature flowing through the cold / hot water coil 15 is set in accordance with the outside air temperature, and free cooling (automatic operation) for cooling and heating is performed. Perform control.

(During cooling) On the central heat source device 5 side,
The cooling water pump 32 is driven, and the cooling water cooled by the cooling tower 31 circulates through the absorption-type cold / hot water generator 30 and discharges waste heat during cold water production to the atmosphere. The chilled water produced by the absorption type chilled / hot water generator 30 is maintained at a predetermined temperature by the temperature control valve 36, and is condensed by the chilled / hot water pump 6 through the chilled / hot water coil 15 of the air conditioner 1 to the system-specific temperature adjusting heat source device 19. Is supplied to the vessel 21. At this time, the bypass switching valve 35 prevents the cooling water from being supplied to the heat exchanger 34.

On the side of the air conditioner 1, the blower 16 is operated, and the return air from the return air duct 11 of the air conditioning zone 9 and the outside air taken in from the outside air supply duct 4 are mixed and passed through the filter 17 to form the cold / hot water coil 15. To be pumped. The pressure-fed air is temporarily cooled in a cold / hot water coil 15 with cold water of a higher temperature set in advance according to the outside air condition so as not to be overcooled in any of the systems, and then the heat source device for temperature adjustment for each system is used. After the secondary cooling in each of the 19 evaporators 25, it is supplied to each air conditioning zone 9.

Refrigerant supply to each evaporator 25 is performed by opening and closing the refrigerant supply on-off valve 23 by on / off control based on a signal from the temperature sensor 12 of each air conditioning zone 9, and occurs at the number of open refrigerant supply on-off valves 23. The capacity control of the compressor 20 is performed by controlling the number of revolutions of the compressor motor. This rotation speed control is controlled so that the low pressure side pressure does not become lower than a certain pressure and the motor output does not overload. If all the refrigerant supply on-off valves 23 are closed, the compressor 20 is stopped.

If the return air drops below the set temperature even though all of the refrigerant supply on-off valves 23 are closed, the bypass switching valve 26 is switched to allow the cold water to connect the cold / hot water coil 15. Bypass so as not to pass.

During overtime operation during cooling and during light load operation in the interim period, the absorption type cold / hot water generator 30 of the central heat source device 5 is used.
Is stopped, the bypass switching valve 35 is switched, the cooling water from the cooling tower 31 is circulated to the heat exchanger 34, and the condenser 2
The exhaust heat of No. 1 is radiated to the cooling water on the side of the cooling tower 31 to enable the operation of the system-specific temperature adjusting heat source device 19.

Therefore, at the time of cooling, the cold / hot water coil 15 incorporated in the air conditioner 1 is, for example, 70% of the design condition.
Only the base load of the degree is processed without a control valve, so that the outlet temperature control of the chilled / hot water coil 15 can be omitted, and the water supply temperature sent to the chilled / hot water coil 15 can be set to be significantly higher than before without changing the performance of the coil. Considering the characteristic that the efficiency of the central heat source device 5 is greatly improved by the increase of the production temperature, the energy saving effect can be reduced even if the negative side due to the operation of the heat source device 19 for temperature adjustment for each system is taken into consideration. Can be increased. In addition, when cooling is required outside of summer time, by operating the system-specific temperature adjusting heat source device 19 mounted on each air conditioner 1, cooling can be performed without operating the absorption-type cold / hot water generator 30. It becomes possible. This is because the cooling load after hours is extremely small compared to daytime,
This is because it can be covered by the heat source device for temperature adjustment, whereby the energy consumption due to the overtime operation is easily measured by measuring the power consumption, and the troublesome operation of the absorption-type cold / hot water generator 30 is avoided. To be released.

(At the time of heating) On the central heat source device 5 side,
The cooling water pump 32 is stopped, and the produced hot water is maintained at a predetermined temperature by the temperature control valve 36.
Is supplied to the condenser 21 through the cold / hot water coil 15 of the air conditioner 1.

The air sent to the cold / hot water coil 15 on the air conditioner 1 side is heated in the cold / hot water coil 15 by hot water of a higher temperature set in advance in any system in accordance with the outside air condition. After being cooled in each evaporator 25 of the heat source unit 19 for another temperature adjustment, it is supplied to each air conditioning zone 9. At this time, the exhaust heat of the system-specific temperature adjusting heat source device 19 is recovered to the circulating hot water on the central heat source device 5 side via the condenser 21.

The supply of the refrigerant to each evaporator 25 is performed by on / off control based on a signal from the temperature sensor 12 in each air-conditioning zone 9 in the same manner as in the cooling, by opening and closing the refrigerant supply on-off valve 23.
Control of the compressor is performed in the same manner as during cooling. In addition, although all of the refrigerant supply on-off valves 23 are open,
When the return air temperature is equal to or higher than the set temperature, the bypass switching valve 26 is switched to bypass hot water so as not to pass through the cold / hot water coil 15.

Further, although the central heat source device 5 is stopped by the command of the temperature sensor, the central heat source device 5
If the return water temperature to the central heat source device 5 excessively rises due to the operation of the system-specific temperature adjusting heat source device 19 from the water supply temperature from the cooling water, the cooling water pump 32 is driven to switch the bypass switching valve 35 to switch the cooling tower 31. Is circulated through the heat exchanger 34 so that the rise in the temperature of the circulating water is radiated to the cooling tower 31 so that the cooling water can be cooled. Therefore, the system-specific temperature adjusting heat source device 19 can be freely used as a cooling heat source device, and therefore, even if there is a partially generated cooling load, it is possible to cope with each case, and an energy saving effect by the heat recovery operation can be expected.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, in the above embodiment,
Absorption type cold / hot water generator 30 as a heat source device of central heat source device 5
However, the present invention is not limited to this, and an electric compression heat pump may be used. However, since heat recovery operation and overtime operation, etc., which have been difficult to adopt the absorption type chilled / hot water generator, have been facilitated by the present invention, if the absorption type chilled / hot water generator is adopted in the present invention, Operation costs and calorie measurement have been made because it is easier to use energy other than electricity, it is possible to suppress the power peak in summer, which is a prominent cooling power, and it is not necessary to operate the heat source device during nighttime cooling. Has the effect of eliminating the problem of

Further, the heat source unit 19 for system-specific temperature adjustment may be a heat pump. In this case, high air can be supplied to the air conditioning zone 9 during heating. HP in FIG. 5 means the heat pump operation in this case.

[0026]

As is apparent from the above description, according to the present invention, the temperature of the cold / hot water flowing from the central heat source device to the cold / hot water coil is set to a higher temperature in accordance with the outside air condition, and the temperature sensor of each air conditioning zone is set. By supplying the refrigerant to the evaporator for each air conditioning zone by ON / OFF control based on the signal from, the temperature control can be simplified and the energy saving effect by the heat recovery operation can be expected. The operation of the central heat source device during the light load operation in the intermediate period is not required, and the evaporator for the air conditioning zone can be freely used for cooling during heating.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a central heat source type air conditioner of the present invention, and is a configuration diagram of an air conditioner installed on each floor.

FIG. 2 is an overall configuration diagram showing one embodiment of a central heat source type air conditioner of the present invention.

FIG. 3 is a configuration diagram showing a relationship between a central heat source device and an air conditioner, showing one embodiment of a central heat source type air conditioner of the present invention.

FIG. 4 is a configuration diagram of a central heat source device showing one embodiment of a central heat source type air conditioner of the present invention.

FIG. 5 is a diagram for explaining an example of a control method according to the present invention.

[Explanation of symbols]

1 ... air conditioner, 2 ... cold and hot water supply pipe, 3 ... cold and hot water return pipe, 4
... outside air supply duct 5 ... central heat source device, 6 ... cold and hot water pump, 9 ... air conditioning zone, 10 ... air supply duct 11 ... return air duct, 12 ... temperature sensor, 15 ... cold and hot water coil 16 ... blowing fan, 19 ... system Separate heat source for temperature control, 2
0: Compressor 21: Condenser, 23: Refrigerant supply opening / closing valve, 25: Evaporator 26: Switching valve for bypass, 30: Absorption type cold / hot water generator
31 cooling tower 34 heat exchanger 35 switching valve for bypass 36 temperature control valve

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-13737 (JP, A) JP-A-3-117837 (JP, A) JP-A-62-37625 (JP, A) JP-A-3-3765 79934 (JP, A) JP-A-4-26167 (JP, A) JP-A-7-19523 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 3/00 F24F 5 / 00 F24F 1/00 F24F 3/044

Claims (3)

(57) [Claims] 1. An air conditioner installed on each floor of a building;
A central heat source device for circulating cold and hot water through each air conditioner,
A plurality of air conditioning zones connected to the air conditioner, a temperature sensor disposed in each air conditioning zone, a cold / hot water coil disposed in the air conditioner, an evaporator disposed for each air conditioning zone, and air A blast fan that circulates a cooling / heating water coil and an evaporator in the order of each air conditioning zone, a system-specific temperature adjusting heat source device connected to each evaporator via a refrigerant supply opening / closing valve, and the central heat source device. A cold / hot water pump that circulates cold / hot water through a cold / hot water coil and a system-specific temperature adjusting heat source device, and sets the cold / hot water temperature of the cold / hot water coil to a higher temperature in accordance with the outside air condition; A central heat source type air conditioner, wherein the refrigerant supply on / off valve is opened and closed to supply refrigerant to each evaporator by on / off control based on a signal from a sensor. 2. The central heat source type air conditioner according to claim 1, wherein the heat source device of the central heat source device is an absorption type cold / hot water generator. 3. A central heat source type air conditioner according to claim 1, wherein said cold / hot water is heat-exchangeable with cooling water on a cooling tower side of said central heat source device.