JPS6071846A - Air-conditioning method of building containing zones with large load fluctuation - Google Patents

Abstract

PURPOSE:To reduce both initial cost and running cost by a method wherein constant air flow operation and variable air flow operation are alternately performed in response to the load conditions to zones with large load fluctuation such as cuisine, dining hall and the like. CONSTITUTION:Constant air flow operation and variable air flow operation are alternately performed in response to the load conditions to zones with large load fluctuation such as cuisine, dining hall and the like in an air-conditioning system, which controls the supply air flow rate and exhaust air flow rate are controlled by a computer. Concretely, various sensors to detect the load of said zones and signal converters are made into an integral body and the various sensors are connected to a single transmission line. The signals sent from the various sensors are processed at a transmission control unit and a general-purpose micro-computer so as to send control signals to a controller to control the supply air flow rate and exhaust air flow rate in order to alternately perform constant air flow operation and variable air flow operation at the air-conditioning of a zone with sharp load fluctuation under computer-control. Due to the above- mentioned mode of operation, the duration of constant air flow operation is shortened, resulting in reducing the running cost under small load.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioning method that can further reduce initial costs and running costs when computer-controlled air conditioning is carried out in a building that has a kitchen, nine cafeterias, etc. with large load fluctuations.

In buildings with large cafeterias that accommodate several hundred people or more, the air conditioning load in the kitchen, machine room, cafeteria, or surrounding perimeter zone varies greatly depending on the day and time of day. The required air supply and exhaust air volume will vary greatly. For example, in the kitchen, various types of cooking equipment are used depending on the type of food being prepared, but the amount of gas equipment used and the number of times that pots are used also differ depending on the type of menu and number of meals that day, and the amount of air exhausted by each hood varies. It changes daily.

In the past, a constant air volume operation method was adopted in which kitchen equipment was supplied and exhausted at a predetermined air volume, regardless of the usage status of the kitchen equipment, or a variable air volume operation method was adopted in which the air supply and exhaust air volume was varied according to the load. .

However, in the former constant air volume operation method, air supply and exhaust are actually carried out in excess of the required load, so running costs are high. In the latter variable air volume operation method, for example, when controlling the rotation speed of a blower motor using an inverter, it is necessary to install this inverter for a motor with a rated capacity that satisfies the maximum required load. from.

The initial cost was excessive.

On the other hand, when controlling air conditioning, etc. using a microcomputer, conventionally the microcomputer is used exclusively for control, and its programs are usually written in machine language or assembler language.
Flexible general-purpose microcomputer 2
For example, it was not possible to program or modify the system using basic languages.

The present invention aims to solve the problems of conventional air conditioning systems, and is intended to solve the problems of conventional air conditioning systems. Constant air volume operation and variable air volume operation are performed alternately depending on the load situation, and at that time, various sensors and signal converters are integrated to detect the load in the zone, and the various sensors are connected with a single transmission line.

A building with a zone with large load fluctuations in which the signals from these various sensors are processed by a transmission control device and a general-purpose microcomputer, and the control signals are transmitted to a controller that controls the supply air volume and exhaust air volume in the zone. This provides an air conditioning method.

Figure 1 is a plan view of an example of the area around the kitchen on a floor with a dining room that can accommodate several hundred people, where A is the dining room, B is the dishwashing room, and C is the service area. Area, D is the main kitchen, E and F are cleaning rooms, G is the kitchen machine room, H is the machine room, ■ is the elevator hall, J is the hall, is the machine room, and L is the central monitoring room. There is.

In such kitchens and machine rooms, the air conditioning load varies greatly depending on the time of day and the pattern of the day. In the present invention, constant air volume operation and variable air volume operation are performed alternately during computer-controlled air conditioning in zones where such load fluctuations are severe.

Figure 2 shows an example of this pattern.2 For example, constant air flow operation is carried out from after 7 a.m. to nearly 1 p.m.
Before and after this constant air volume operation, variable air volume operation is performed. This mode of operation shortens the time for constant air volume operation and reduces running costs at low loads.In addition, even in variable air volume operation, when the rotation speed of the blower motor is controlled by an inverter (frequency control), the average air volume economic coefficient (1,
1 to 1.3), and the starting current of the blower motor at the minimum frequency of the inverter does not exceed the rated capacity of the inverter, so for variable air volume control. The capacity of the control equipment is reduced, and the initial cost can be reduced.

In constructing a system that alternately performs constant air volume operation and variable air volume operation, the present invention includes improvements that have not been made in the prior art to the control system itself. To explain this with reference to FIG. 1, numeral 1 in FIG. 1 shows numerous hoods installed in the kitchen, 2 an automatic damper for exhaust, 3 a temperature sensor, and 4 a slight differential pressure sensor. Each of the exhaust hoods 1 is configured such that when the exhaust hood is used, its usage status is detected by an electric signal following the operation of a beam switch. Therefore, this hood 1 itself constitutes a type of sensor. Reference numeral 5 indicates an inverter that controls the rotation speed of the air supply/exhaust fan. In the present invention, each sensor 1 to 4 is a signal converter (
(not shown), and each sensor 1 to 4 is connected by a single transmission cable 6. An optical fiber cable is used as the transmission cable 6 and connected in a loop. The signals from each sensor 1 to 4 converted by the signal converter are received by the transmission control device 7 and processed. For this reason, in the present invention, a general-purpose microcomputer 8 with a basic language, which is a microcomputer exclusively for control, is installed as in the prior art. A converter 9 transmits the calculation results of the microcomputer 8 to the inverter as a control signal. This system uses various sensors.
A mechanism (transmission control device 7) that processes signals from 1 to 4?
This system has an interface mechanism with the A-use microcomputer 8, and allows the system program to be created or modified using a versatile programming language, and by simply adding protection against disturbances to the transmission control device 7. The system is constructed to have reliability equivalent to that of a dedicated control microcomputer. This transmission control device 7 uses RAM memory to allow programs to be created and changed at will, but in order to avoid the risk of the RAM memory being destroyed due to a power outage or the like.

It is possible to provide a function in which an abnormality in a program is detected and the original program is automatically rewritten in the RAM in the general-purpose microcomputer 8 in response to this abnormality signal.

The system of the present invention is also characterized in that the various sensors 1 to 4 and the signal converter are integrated and the various sensors are connected in a loop with a single transmission cable. In the past, various sensors were usually individually connected to a control-dedicated microcomputer (or transmission control device). In other words, the conventional system did not have a configuration in which each of the various sensors was equipped with a signal conversion function, so individual wiring was required for each sensor in order to detect field lightning using a program.

For this reason, there is a lot of wiring (and the initial cost is high.In the system of the present invention, various sensors 1 to 4
By installing a signal converter in each, it is possible to check for abnormalities in the program, and by connecting these various sensors and signal converters in a loop and using an optical fiber cable as the transmission cable 6, it is possible to check for abnormalities in the program. The previously completely unprotected parts were constructed into a more protected system, reducing initial costs and improving system reliability.

3 and 4 show an example of a hood damper (corresponding to the hood damper 1 in FIG. 1) suitable for detecting the usage status of a kitchen hood. As mentioned above, the load varies greatly depending on the usage status of the kitchen hood.
It is convenient to apply the hood damper shown in FIGS. 3 and 4 to detect this load variation. As shown in Figure 2, this hood damper is installed inside the exhaust port 11 of the hood 10 (
It is constructed by attaching a multi-blade damper 12 (inside the hood 10). This damper 12 is opened and closed by rotating one blade 13 around a support shaft 14 by an interlocking rod 14, as shown in FIG. This opening/closing operation is performed by rotating the arm 15. This arm 15 is pulled by a torque spring 16 in the direction in which the blades 13 open, and when the wire 17 is pulled against this spring 16, the arm 15 rotates in the direction in which the blades 13 are closed. That is, when the kitchen is used, the blades 13 are opened by the torque spring 16, and when not in use, the wires 17 are opened.
When the arm 15 is rotated, the limit switch 18 is activated and the usage status of the damper can be detected by an electric signal. This is what I did.

In addition to being able to detect usage conditions, this hood damper is also advantageous in that it is easier to install in existing equipment than conventional electric dampers.

In other words, in conventional variable air volume operation for kitchens, etc., an electric damper is installed in the air passage in the attic where the hood is connected, and resistance is applied on the discharge side or suction side of the blower, or the rotation speed of the electric motor is changed. was adopted, but
In this case, since the electric damper is hidden in the ceiling, it is impossible to check whether it is open or closed, and when adding it to existing equipment, it is necessary to remove the ceiling and repair it again.
Use of the hood damper shown in FIGS. 3 and 4 eliminates this problem and is very advantageous.

As described above, the present invention provides an air conditioning method that significantly reduces both running costs and initial costs as an air conditioning system for buildings having zones with large load fluctuations such as kitchens, and greatly contributes to economical air conditioning. It is something to do.

[Brief explanation of the drawing]

Fig. 1 is an equipment layout system diagram showing the kitchen area of a building to which the air conditioning method of the present invention is applied, Fig. 2 is a diagram for explaining the operation method according to the air conditioning method of the present invention, and Fig. 3 is A hood damper applied to the air conditioning method of the present invention is a schematic vertical cross-sectional view, and FIG. 4 is an enlarged schematic vertical cross-sectional view of the damper portion of FIG. 3. 1. Food damper, 2. Electric damper. 3. Temperature sensor, 4. Slight differential pressure sensor. 5. Inverter, 6. Transmission cable (optical fiber cable), 7. Transmission control device. 8...Microcomputer, 9...Converter. 10... Kitchen hood, 12... Damper, 18... Limit switch. Applicant Takasago Thermal Engineering Co., Ltd.

Claims (3)

[Claims] (1) In an air conditioning system that controls supply air volume and exhaust air volume by computer, it is possible to alternately perform constant air volume operation and variable air volume operation depending on the load situation for zones with large load fluctuations such as the kitchen and two dining rooms. This air conditioning ventilation method is characterized by integrating various sensors and signal converters for detecting the load in the zone, connecting the various sensors with a single transmission line, and transmitting the signals from the various sensors. Processed by a control device and a general-purpose microcomputer. An air conditioning method for a building having a zone with large load fluctuations, which transmits a control signal to a controller that controls the supply air volume and exhaust air volume of the zone. (2) The air conditioning method according to claim 1, wherein the transmission line is an optical fiber cable. (3) The air conditioning method according to claim 1 or 2, wherein one of the six sensors is an exhaust hood usage status monitoring sensor.