JPH0861703A - Central heat source type air conditioning system - Google Patents

Abstract

PURPOSE: To simplify a temperature control and to obtain an energy-saving effect by a heat recovery operation. CONSTITUTION: This system is equipped with an air conditioner installed on the floor of each story of a building, central heat source equipment for circulating cold-hot water through each air conditioner, a plurality of air conditioning zones connected to the air conditioner, a temperature sensor provided in each air conditioning zone, a cold-hot water coil 15 provided in the air conditioner, an evaporator 25 provided for each air conditioning zone, a fan 16 for circulating air through each air conditioning zone in the sequence of the cold-hot water coil 15 and the evaporator 25 and a heat source machine 19 for temperature regulation for each line connected to each evaporator 25 through a refrigerant supplying on-off valve 23. Accordingly, a cold-hot water pump whereby the cold-hot water produced by the central heat source equipment is circulated through the cold-hot water coil 15 and the heat source machine 19 for temperature regulation for each line is provided, and the temperature of the cold-hot water in the cold-hot water coil 15 is set at a rather high temperature in accordance with the condition of outdoor air, the refrigerant supplying on-off valve 23 being opened and closed by an on-off control on the basis of a signal from the temperature sensor of each air conditioning zone, so as to supply a refrigerant to each evaporator 25.

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 suitable for use in 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 warm water is switched from season to season to an air conditioner installed on each floor of a building. In this method, when extracting the system that supplies to multiple rooms from one air conditioner on each floor and controlling the indoor temperature according to the indoor load fluctuation for each system, the conventional technology is to configure the air conditioner. Depending on the cooling coil or heating coil
The amount of air controlled to the target temperature by cooling or heating each 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 method of supplying by changing the ratio is adopted.

[0003]

However, in the above-mentioned conventional method, there is a problem that high-quality temperature control is required because of the necessity of performing temperature control by proportional control, resulting in an increase in equipment cost. There is. Also, when the production of cold water and hot water is switched and supplied for each season, if the cooling request system and the heating request system appear simultaneously in the supply range of one air conditioner in winter, the temperature control of the cooling request system will occur. It became impossible, and the room temperature was slowed down, and energy saving operation by heat recovery operation was also impossible.

The present invention is to solve the above-mentioned conventional problems, in which the temperature of cold / hot water flowing from the central heat source device to the hot / cold water coil is set to a high temperature in accordance with the outside air condition, and the temperature sensor in each air conditioning zone is set. By supplying the refrigerant to the evaporator for each air conditioning zone by the 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, and the overtime operation during cooling and An object of the present invention is to provide a central heat source type air conditioner that does not require operation of the central heat source device during light load operation in the intermediate period and can freely use the evaporator for the air conditioning zone for cooling during heating. It is what

[0005]

To this end, 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 in each air conditioner 1. And a plurality of air conditioning zones 9 connected to the air conditioner 1.
A temperature sensor 12 arranged in each air conditioning zone 9, a cold / hot water coil 15 arranged in the air conditioner 1, an evaporator 25 arranged in each air conditioning zone 9, and an air cold / hot water coil 1
5, the blower fan 16 that circulates in the air conditioning zone 9 in the order of the evaporator 25, the system-dependent temperature adjustment heat source device 19 connected to each evaporator 25 via the refrigerant supply opening / closing valve 23, and the central heat source device 5. A cold / hot water pump 6 that circulates the manufactured cold / hot water to the cold / hot water coil 15 and the system-by-system temperature adjusting heat source device 19, and sets the cold / hot water temperature of the cold / hot water coil 15 to a higher temperature according to the outside air condition. The on / off control based on the signal from the temperature sensor 12 of each air conditioning zone 9 opens and closes the refrigerant supply opening / closing valve 23 to supply the refrigerant to each evaporator 25. It should be noted that the numbers added to the above-mentioned configurations are for comparison with the drawings in order to facilitate the understanding of the present invention, and the configurations of the present invention are not limited thereby.

[0006]

In the present invention, the supplied air is cooled or heated in the cold / hot water coil by cold / hot water having a higher temperature set in advance in any system in accordance with the outside air condition, and then the temperature adjustment for each system is performed. After being cooled by an evaporator for water supply, 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 using the heat source unit for cooling during overtime operation during cooling, during light load operation in the middle period, and when using the system-specific temperature adjustment heat source device as the cooling heat source device, stop the heat source device of the central heat source device and 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 the operation of the system-specific temperature adjustment heat source machine.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is an overall configuration diagram showing an 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 includes a hot and cold water supply pipe 2, It is connected to the central heat source device 5 via the cold / hot water return pipe 3 and the 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 is provided with a pump 6 and heat exchange. It is connected to the central heat source device 5 via the container 7. The outside air is sucked by the blower 8 and cooled or heated by the heat exchanger 7, and then is 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 / dehumidifying or heating / humidifying the outside air to be taken in, and plays a role of a humidity controller for adjusting the humidity of the outside air. However, it is not always essential and the air conditioner 1 side is humidified. 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. The air conditioner 1
The air-conditioning zones 9 of a plurality of systems having different heat loads are connected via a supply air duct 10 and a return air duct 11. The air-conditioning zone 9 is a partitioned room or a specific area to be air-conditioned.
Is provided.

FIG. 1 shows a central heat source type air conditioner according to the present invention.
1 is a configuration diagram of an air conditioner 1 installed on each floor according to an embodiment. The air conditioner 1 is basically composed of a casing 13, a hot / cold water coil 15 connected to the central heat source device 5, a plurality of blower fans 16, a filter 17, and a heat source device 19 for temperature adjustment for each system. Heat source device 19 for temperature adjustment by system
Has a compressor 20, a condenser 21, and a refrigerant liquid reservoir 22, to which a plurality of refrigerant supply opening / closing valves 23, an expansion valve 24, and an evaporator 25 are connected in parallel by piping. Each evaporator 25
Is arranged on the downstream side of the cold / hot water coil 15. An air supply duct 10 that supplies conditioned air to the air conditioning zones 9 of the plurality of systems described in FIG. 3 is connected to a position of the casing 13 that faces each evaporator 25.

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 bypasses cold / hot water to the cold / hot water coil 15, and is configured such that the cold / hot water exiting the cold / hot water coil 15 is heat-exchanged with the condenser 21. .

FIG. 4 is a block diagram of a central heat source device 5 showing an embodiment of the central heat source type air conditioner of the present invention. Absorption-type cold / hot water generator 30, which is a heat source machine, and absorption-type cold / hot water generator 30
A cooling tower 31 and a cooling water pump 32 for circulating cooling water during cooling, and a cold / hot water pump 6 for circulating cold / hot water from the absorption-type cold / hot water generator 30 to the air conditioner 1.
A heat exchanger 34 for exchanging heat between cooling water and cold / hot water,
The bypass switching valve 35 for allowing the cooling water to bypass the heat exchanger 34, and the cold / hot water of the cold / hot water return pipe 3 are directly supplied to the cold / hot water pump 6 side to control the cold / hot water temperature of the cold / hot water supply pipe 2. And a temperature control valve 36 for As the heat source of the absorption-type cold / hot water generator 30, gas, petroleum, or steam is used.

Next, the operation control method of the present invention having the above structure will be described with reference to FIG. FIG. 5 is a diagram for explaining one example of the control method of the present invention, in which the control sets the temperature of the water to be supplied to the cold / hot water coil 15 according to the outside air temperature, and the free cooling (automatic operation) of cooling and heating is performed. Take control.

(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 in the absorption-type cold / hot water generator 30 to release the exhaust heat at the time of manufacturing the cold water 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, passes through the chilled / hot water coil 15 of the air conditioner 1 by the chilled / hot water pump 6, and condenses the heat source device 19 for temperature regulation by system. Is supplied to the container 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 so that 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 pass through the filter 17 to cool / hot water coil 15 Pumped to. The pressure-fed air is temporarily cooled in the hot / cold water coil 15 with cold water having a higher temperature set beforehand according to the outside air conditions so as not to be overcooled in any system in advance, and then the system-specific temperature adjusting heat source unit After being secondarily cooled by each evaporator 25 of 19, the air is supplied to each air conditioning zone 9.

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

When the return air falls 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 cool the cold / hot water coil 15. Bypass so that it does not pass.

During the overtime operation during cooling and the light load operation during the intermediate 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 cooling tower 31 side to enable the operation of the system-specific temperature adjustment heat source unit 19.

Therefore, during cooling, the cold / hot water coil 15 incorporated in the air conditioner 1 is, for example, 70% of the design condition.
Since only a moderate base load is processed without a control valve, control of the outlet temperature of the hot / cold water coil 15 can be omitted, and the temperature of the water to be sent to the cold / hot water coil 15 is 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 manufacturing temperature, therefore, the energy saving effect can be obtained even if the negative side due to the operation of the heat source device 19 for temperature adjustment for each system is added. Can be increased. In addition, when cooling is required outside the summer time, by operating the system-specific temperature adjustment 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 will be possible. This is because the cooling load after hours is extremely small compared to daytime,
This is because the heat source machine for temperature adjustment can cover the energy consumption by overtime operation by measuring the power consumption, and the troublesome operation of the absorption cold / hot water generator 30. To be released.

(At the time of heating) On the central heat source device 5 side,
The cooling water pump 32 is stopped, the produced hot water is maintained at a predetermined temperature by the temperature control valve 36, and the cold / hot water pump 6
Is supplied to the condenser 21 through the cold / hot water coil 15 of the air conditioner 1.

The air pressure-fed to the cold / hot water coil 15 on the side of the air conditioner 1 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, and then the system. After being cooled by each evaporator 25 of the heat source device 19 for another temperature adjustment, it is supplied to each air conditioning zone 9. At this time, the exhaust heat of the system-by-system temperature adjustment heat source device 19 is recovered via the condenser 21 to the circulating hot water on the side of the central heat source device 5.

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

Further, even though the central heat source device 5 is stopped by the command of the temperature sensor, the central heat source device 5
When the return water temperature to the central heat source device 5 from the water supply temperature from the engine rises excessively due to the operation of the system-specific temperature adjusting heat source device 19, the cooling water pump 32 is driven to switch the bypass switching valve 35 to switch the cooling tower 31. The cooling water is circulated through the heat exchanger 34, and the rise in the circulating water temperature is radiated to the cooling tower 31 side so that the cooling water can be cooled. Therefore, the system-by-system temperature adjusting heat source device 19 can be freely used as a cooling heat source device, so that even if there is a partially generated cooling load, it can be coped with each time, 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 embodiments and various modifications can be made. For example, in the above embodiment,
As a heat source device of the central heat source device 5, an absorption type cold / hot water generator 30
However, the electric compression type heat pump may be used. However, since the present invention facilitated heat recovery operation and overtime operation, which were difficult to adopt the absorption-type cold / hot water generator until now, if the absorption-type cold / hot water generator is adopted in the present invention, It is easy to use energy other than electricity, and it is possible to suppress the peak electric power in summer, which is the outstanding cooling power, and it is not necessary to operate the heat source device during nighttime outdoor cooling. It also has the effect of eliminating the problem.

Further, the heat source device 19 for temperature adjustment for each system may be a heat pump, and in that case, a higher 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 cold / hot water flowing from the central heat source device to the cold / hot water coil is set to a high 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 the 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, and the overtime operation during cooling and It is not necessary to operate the central heat source device during the light load operation in the intermediate period, and the evaporator for the air conditioning zone can be freely used for cooling during heating.

[Brief description of drawings]

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

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

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

[Explanation of symbols]

1 ... Air conditioner, 2 ... Cold / hot water supply pipe, 3 ... Cold / hot water return pipe, 4
... Outside air supply duct 5 ... Central heat source device, 6 ... Cold / hot water pump, 9 ... Air conditioning zone, 10 ... Air supply duct 11 ... Return air duct, 12 ... Temperature sensor, 15 ... Cold / hot water coil 16 ... Blower fan, 19 ... System Separate heat source for temperature adjustment, 2
0 ... Compressor 21 ... Condenser, 23 ... Refrigerant supply opening / closing valve, 25 ... Evaporator 26 ... Bypass switching valve, 30 ... Absorption type cold / hot water generator,
31 ... Cooling tower 34 ... Heat exchanger, 35 ... Bypass switching valve, 36 ... Temperature control valve

Claims (3)

[Claims] 1. An air conditioner installed on each floor of a building,
Central heat source device for circulating cold and hot water to each air conditioner,
A plurality of air conditioning zones connected to the air conditioner, temperature sensors arranged in each air conditioning zone, cold and hot water coils arranged in the air conditioner, evaporators arranged for each air conditioning zone, and air. Blow fan that circulates the hot and cold water coil to each air conditioning zone in the order of the evaporator, the heat source unit for temperature adjustment for each system connected to each evaporator through the refrigerant supply on-off valve, and the central heat source device A cold / hot water pump that circulates cold / hot water to a cold / hot water coil and a heat source device for temperature adjustment for each system, and sets the cold / hot water temperature of the cold / hot water coil to a higher temperature according to the outside air condition, and the temperature of each air conditioning zone. A central heat source type air conditioner characterized by opening and closing the refrigerant supply opening / closing valve 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. The central heat source type air conditioner according to claim 1, wherein the cold / hot water can exchange heat with the cooling water on the cooling tower side of the central heat source device.