JPS6266041A - Air conditioner - Google Patents

Abstract

PURPOSE:To make possible to operate an air conditioner always under an optimum conditions and stably by providing air volume changing means and capability changing means which make primary correction to the capacities of a blower and a heat source machine according to the amount of control for a damper and providing air volume determination means and capability determination means which finally determine the capacities of the blower and the heat source machine based on the pressure and temperature in a duct after controlling the damper. CONSTITUTION:A air volume changing means 20 is operated based on the control amount of a damper 4 to make primary correction to the capacity of a blower 5, and changing means 21 is operated to make primary correction to the capability of a heat source machine 17, and the pressure and temperature in a duct 6 after controlling a damper 9 are measured by an operation state measuring device 22 which receives as inputs detection signal of a pressure detection means 16 and a temperature detection means 5. The capacity of the blower 5 is finally corrected by operating a air determination means 23 according to the value of the air changing means 20, and based on the output of this air determination means 23 the blower 5 is controlled by a blower control means. Further, by the results of temperature measuring by the operation state measuring means 22 and the value of a capability changing means 21, a capability determination means is operated to finally correct the capability of the heat source machine 17, and its capability is controlled by a capability control means 26.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a duct type air conditioner that employs a variable air volume control system that can independently adjust the room temperature of each room.

[Conventional technology]

Central air conditioning systems use air ducts to distribute temperature-controlled air to each room for air conditioning, and can easily incorporate humidifiers and high-performance filters, as well as external air processing and total heat exchangers. Beat pump chillers and fan coils allow for high-quality air conditioning, and since the air-conditioned room only has an outlet and an inlet, the indoor space can be used effectively, and there are fewer problems with the heat transfer system. It has many advantages compared to the F1 system and packaged air conditioner distributed distribution system, and for this reason, it is widely used in building air conditioning. Among them, the variable air volume control method (hereinafter referred to as VAV method), which allows for energy-saving series operation, can independently control the temperature of each room with a different heat load, and can also stop air conditioning in rooms that are not in use. Operating costs can be reduced by varying the power of the blower depending on the amount of air required, and the capacity of the heat source device can be designed to be smaller by considering the simultaneous usage rate.

For the above VAV system, there are 2
There are two methods. One is a method using a bypass type VAV unit, which adjusts the ratio of the amount of air blown into the room and the amount of air directly returned to the heat source equipment (bypassed) depending on the indoor load. This method is often used in systems using packaged air conditioners, where it is difficult to control the capacity of the heat source equipment because the amount of air blown is constant, but there is no energy saving effect by controlling the blower.

Another method uses an aperture-type VAV unit. This method detects the pressure inside the duct, which changes according to the opening degree of the damper, and controls the capacity of the blower so that this value becomes the set value. (The air temperature inside the duct is controlled to be constant), the required capacity of the heat source equipment is reduced, and at the same time the power of the blower is reduced.

A blower associated with damper control in the VAV system.

The conventional technology related to the capacity control method of heat source equipment is
-14979, Special Publication No. 55-22696, Special Publication No. 55
5-24022, Japanese Patent Publication No. 55-44853, etc. FIG. 4 is a system configuration diagram of these conventional air conditioners. In the figure, 1 is a room to be air-conditioned, and here a case of three rooms is shown. 2 is an air handling unit placed in the ceiling of room 1, and air filter 3. Heat exchange lid 4. It is composed of a blower 5. 6 is a main duct connected to the air outlet of this air handling unit 2, 7 is three branch ducts branched from this main duct 6 according to the number of rooms, and 8 is a throttle inserted in the middle of this branch duct. 9 is a damper rotatably installed in the VAV unit 8, 10 is an air outlet installed at the end of the duct 7, and 11 is a suction installed at the bottom of the door of the room 1. Port, 12 is a ceiling suction port provided on the ceiling of the hallway, 13
14 is a room thermostat installed in each room 1; 15 is a temperature sensor installed in the main duct 6; 16 is a pressure detector also provided in the main duct 6, 17
is a heat source device such as a heat pump connected to the heat exchanger 4.

In the conventional air conditioner configured as described above, the opening degree of the damper 9 is adjusted to an arbitrary position according to the temperature difference between the set temperature set by the user on each room thermostat 14 and the detected current air temperature. Adjust. The pressure inside the main duct 6 changes depending on the opening degree of the damper 9, which is detected by the pressure detector 16, and the capacity of the blower 5 is changed to prevent excessive pressure. In addition, since the outlet air temperature of the heat exchanger 4 changes as the air flow rate changes, this temperature is detected by the temperature detector 15 and the capacity of the heat source device 17 is controlled so that the air temperature reaches a preset value. do.

The air, which has been adjusted to a substantially constant temperature in this manner, is blown out into the room 1 from the air outlet 10 at an air volume that corresponds to the magnitude of the indoor heat load. The air that has been conditioned in the room 1 flows from a suction port 11 through a space such as a hallway to a ceiling suction port 12, and returns to the air handling unit 2 via a suction duct 13.

Although FIG. 4 shows a method in which the return air is returned using a corridor or the like, there is also a method in which a return duct is provided from each room 1 to the air handling unit 1-2 to further improve controllability and energy saving. Further, in FIG. 4, the branch duct 7 is branched from the main duct 6, but there is also a method in which the main duct 6 is not provided and the branch duct 7 is arranged in an octopus-like shape from the air handling unit 2. In addition to the ceiling-embedded type shown in FIG. 4, the air handling unit 2 includes floor-standing types, ceiling-suspended types, and even a type that incorporates a gas furnace.

[Problem that the invention seeks to solve]

In an air conditioner using a conventional throttle-type VAV unit as described above, if the total opening of each damper 9 changes suddenly due to a significant change in the setting value of the room thermostat 14, etc., the air volume may be particularly restricted. There is a problem in some cases. In other words, the pressure inside the main duct 6 that changes due to the change in the opening degree of the damper 9 is detected by the pressure detector 16, the air flow rate is controlled to maintain a constant pressure, and the Suita air temperature that changes due to the change in the air flow rate is detected by the temperature sensor 15. , and controls the capacity of the heat source device 17 to maintain a constant temperature. However, if the opening degree of the damper 9 changes significantly, changes in the air flow rate and capacity cannot be sufficiently followed, especially when the heat source device 17 When a pump was used, the pressure in the refrigeration circuit could temporarily fluctuate, making stable operation impossible. Additionally, if the rate of change in air flow rate relative to the difference between set pressure and detected pressure, and the rate of change in capacity relative to the difference between set temperature and detected temperature are set larger than necessary, pressure and temperature hunting will occur, making stable operation impossible. There was a problem.

This invention solves the above-mentioned conventional problems, and aims to provide an air conditioner that can stably operate a heat source unit even if the damper opening changes significantly due to fluctuations in heat load.

[Means for solving problems]

The air conditioner according to the present invention has a heat load measurement method that measures heat load based on the output signal of a room thermostat for each room that detects the temperature of each room to which cold and hot air from a heat source device is distributed through a duct. a damper control means for controlling the opening degree of a damper provided in the branch duct based on the measurement result, an air blowing amount changing means for changing the capacity of the blower based on the damper control amount, and a capacity of the heat source device. A capacity changing means, an operating state measuring means for measuring the operating state based on output signals after damper control of a pressure detector and a temperature sensor provided in the duct, and a final air blowing amount based on the measurement results. It is composed of an air flow rate determination and blower control means that determines and controls the amount of air blown, and a capacity determination and capacity control means that determines and controls the capacity of the heat source device based on the measurement results of the measurement means.

[Function] ′ In this invention, the air flow rate changing means and the capacity changing means act to primarily modify the capacities of the blower and the heat source device according to the damper control amount, and the air flow rate determining means and the capacity determining means, The capacity of the blower and heat source equipment is ultimately determined based on the pressure and temperature inside the duct after damper control measured by the operating state measuring means, which allows the heat source equipment to operate stably under optimal conditions at all times. It can be done.

〔Example〕

FIG. 1 is an overall principle block diagram showing an embodiment of an air conditioner according to the present invention. As is clear from FIG. 1, there is a heat source device 17 such as a heat pump connected to the heat exchanger 4 of the air handling unit 2, and a blower 5 that conveys cold and hot air generated by the heat source device 17 and the heat exchanger 4. , a main duct 6 connected to this blower 5, a damper 9 for adjusting air volume arranged in a branch duct 7 of this main duct 6, a pressure detection @ 16 for detecting the pressure inside the main duct 6, and a blowout. Temperature detector 1 that detects air temperature
5 and a room thermostat 1 installed in each room 1
4, and receives the set temperature signal and detected temperature signal of the room thermostat 14 as inputs.
The magnitude of the heat load in each room 1 is measured, and based on the output, the damper control means 19 is controlled to control the opening degree of each damper 9, and the air flow rate changing means 20 is controlled based on the control amount of the damper 4. The capacity of the blower 5 is temporarily corrected by operating it. Furthermore, the capacity changing means 21 is operated based on the control amount of the damper 9 to greatly modify the capacity of the heat source @17, and then the pressure and temperature inside the duct 6 after the control of the damper 9 are detected by the pressure detector 16. The pressure is measured by the operating state measuring means 22 which inputs the detection signal of the temperature detector 15, and the air blowing amount determining means 23 is operated based on the pressure measurement result and the value of the air blowing amount changing means 20 to finally correct the capacity of the blower 5. Then, the blower 5 is controlled by the blower control means 24 based on the output of the air blowing amount determining means 23. Further, the capacity determining means 25 is operated based on the temperature measurement result of the operating state measuring means 22 and the value of the capacity changing means 21 to make a final correction to the capacity of the heat source device 17. 17 capacities are controlled by capacity control means 26.

In FIG. 1, the same reference numerals as in FIG. 4 indicate the same or corresponding parts.

FIG. 2 is a circuit diagram showing a specific example of functional means corresponding to the principle configuration of FIG. CPU29. Memory 30.
Timer 31. Input circuit 32. It is composed of an output circuit 33. 34 is an analog multiplexer to which the detection signals of each room thermostat 14, pressure detector 16 and temperature sensor 15 are input; 135 is an A/D converter that converts the output into digital; the output is sent to the input circuit 32;
given to. 36a to 36c are photocoupler/SSR units connected to the output circuit 33;
An inverter 37 that controls the electric motor 17a of the heat source 8117 is connected to the SR 36a. In addition, photocoupler
A blower controller 38 consisting of a thyristor or an inverter that controls the electric power of the blower 5 is connected to the 5SR36b, and a photocoupler 5SR36c
A damper controller 39 that controls the stepping motor 9a of the damper 9 is connected. 40 is an AC and DC power source that drives each device.

In addition, in FIG. 2, circuits of auxiliary devices such as the operating switch and four-way valve of the heat source device 17 are omitted.

Next, the operation of the above embodiment will be explained during heating with reference to the flowchart shown in FIG.

Note that the control program shown in FIG. 4 is stored in the memory 30 of the microcomputer 28.

When the air conditioner starts heating operation, the control program shown in Figure 4 starts, first, each room thermostat 1 is activated.
4, signals of the set room temperature and the current room temperature are sent to the analog multiplexer 34, A/D converter 35, and input port a! l! i3
It is input to the CPU 29 via 2'fr (step 41
), the heat load of each room 1 is measured from the temperature difference (step 42). Depending on the magnitude of this heat load, the amount of change in the opening degree of the damper 9 is determined in the next step 43. The amount of change in opening proportional to the size of the temperature difference is transmitted from the CPU 29 to the damper controller 39 via the output circuit 33° photocoupler/SSR unit 36c, and is transmitted to the stepping motor 9.
a. Adjust the damper 9 (step 44).

The damper 9 can be controlled by controlling the damper 9 in two positions, fully open and fully closed, and controlling the room temperature to the set value (ON).
10FF control) and a method of setting the damper 9 to an arbitrary opening degree that is balanced with the thermal load (proportional system VS>), and either method may be adopted.

In this way, the opening degree of the damper 9 is changed for each room 1 (step 45). The total opening degree of the damper 9 at this time or the amount of change in the total opening degree is stored in the memory 30 (step 46).

Next, open loop control is performed according to the amount of change in the opening degree of the damper 9. When the pressure inside the main duct 6 is constant, the capacity of the air blower 815 relative to the total opening of each damper 9 can be determined in advance, although it will vary slightly depending on the pressure loss of the branch duct 7, etc., and the amount of change in opening can be calculated in advance. The rotational speed of the air blower 815 is first corrected by the value obtained by multiplying by a constant (step 47
). In addition, when the blowing air temperature is constant, the approximate rotational speed of the pressure wJ machine (not shown) of the heat source device 17 relative to the weight (a function of the damper opening degree) should be determined in advance, although it will vary slightly depending on the outside temperature, etc. The rotational speed of the compressor is first corrected by the value obtained by multiplying the opening change amount ζζ constant (step 48). After the damper 9 is controlled, the pressure inside the main duct 6 changes in a short time, and the humidity changes slowly due to the heat capacity of the heat exchanger 4 and the like.

This pressure is detected by a pressure detector 16, and the temperature is detected by a temperature detector 15, and closed loop control is performed based on these values.

The signals from the detectors 15 and 16 are input to the CPU 29 via the analog multiplexer 34 (step 49).

The value obtained by multiplying the difference between the pressure set value stored in the memory 30 in advance and the detected pressure by a constant is added to the rotation speed of the blower 5 that has been primarily corrected, and the operating rotation speed is determined (step 50). The value obtained by multiplying the difference between the temperature set value and the detected temperature, which is also stored in the memory 30, by a constant is added to the rotation speed of the compressor that has been primarily corrected, and the operating speed is determined (step 52).

The rotation speed control signal of the blower 5 is sent from the CPU 29 to the output circuit 3.
3. Photocoupler 5SR36b, blower controller 3
8 and is output to the blower 5 (step 51).

In addition, the rotation speed control signal of the compressor is also output from the CPU 29.
3311- Coupler-3S R36a, inverter 37
is output to the compressor via (step 53). These series of controls are repeated at regular time intervals by the timer 31.

In the above embodiment, following the control of the damper by the means 19, the changing means 20. ．． Changing the air flow rate and capacity by means 21, measuring the operating state by measuring means 22, means 23.
The blower is controlled by means 24 and the capacity is controlled by means 25 and 26, except that the air quantity and capacity changing means 20 and 21 precede the air quantity and capacity determining means 23 and 25. Not that important.

In addition, the above embodiment is a blower 5 in a constriction type VAV system.
Regarding the method of controlling the heat source 8117, in the case of the bypass type VAV method, since the capacity of the blower 5 is not controlled, only the capacity of the heat source device 17 is controlled.

Furthermore, in the above embodiment, the heat source device was explained as a capacity-controlled heat pump, but this is different! The same applies to sources such as volume control type furnaces.

〔Effect of the invention〕

As described above, according to the present invention, open-loop control of the capacity of the blower and heat source device is performed by changing the opening degree of the damper, and the final closed-loop control of the capacity of the blower and heat source device is performed based on the pressure and temperature inside the duct after changing the opening degree. Since this control method is used, the heat source equipment can be stably operated under optimal conditions even if the damper opening changes significantly due to fluctuations in heat load, etc.

[Brief explanation of drawings]

Fig. 1 is an overall principle block diagram showing an embodiment of the air conditioner of this invention, Fig. 2 is a circuit diagram showing a specific example corresponding to the principle structure of this invention, and Fig. 3 is the operation of Fig. 2. Flowchart 1 for explaining this, and FIG. 4 are system configuration diagrams of a conventional air conditioner. 1 ・mff1.2... Air handling unit, 5... Blower, 6... Main duct, 7... Branch duct, 9... Damper, 14 Room thermostat, 15
- Temperature detector, 16... Pressure detector, 17... Heat source device, 18... Heat load measuring means, 19... Damper control means,
20. Air flow rate changing means, 21. Capacity changing means, 22.
Operating state measuring means, 23 - Air blowing amount determining means, 24...
Blower control means, 25...capacity determining means, 26 capacity control means, 28...microcomputer. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Procedural amendment (voluntary)

Claims (3)

[Claims] (1) A heat source device that generates cold or hot air, a blower and duct that supplies and distributes the cold and hot air from this heat source device to each room,
A damper that is placed on a branch of this duct controls the room temperature by varying the air volume, a heat load measuring means that measures the heat load by inputting the set value and detection signal of the room thermostat in each room, and A damper control means for controlling the opening degree of the damper based on the output, an air flow rate changing means for changing the capacity of the blower based on the damper control amount, a capacity changing means for changing the capacity of the heat source device, and a an operating state measuring means for measuring the operating state based on detection signals of a pressure detector that detects pressure and a temperature sensor that detects the air temperature in the duct; and an operating state measuring means that measures the operating state based on the output of the operating state measuring means. an air blowing amount determining means for correcting and determining the obtained air blowing amount; a blower control means for controlling the capacity of the blower based on the output of the air blowing amount determining means; An air conditioner comprising a capacity determining means for correcting and determining the capacity, and a capacity controlling means for controlling the capacity of a compressor based on the output of the capacity determining means. (2) The air conditioner according to claim 1, wherein the blower control means adjusts the rotational speed of the blower. (3) The air conditioner according to claim 1, wherein the capacity control means is adapted to adjust the rotation speed of the compressor when the heat source device is a heat pump.