JPS62225842A - Air conditioner - Google Patents

Abstract

PURPOSE:To make it possible to accurately control the room temperature when a thermal load is high and to reduce the motive power of a blower when the thermal load is low by carrying out setting of an optimum blast amount and blast temperature in accordance with the magnitude of the thermal load of each room. CONSTITUTION:Stepping motors for operating the opening degree of respective dampers are connected to damper control means 19, and the stepping motors are operated by control output signals according to the thermal loads of respective rooms to control the opening degree of the dampers 9 in accordance with the thermal loads. Set pressure determining means 20 determines the pressure within a duct from the value of a maximum thermal load or a total thermal load within a predetermined period of time in each room 1. Set temperature determining means 21 determines the blast temperature within the duct 6 from the value of the maximum thermal load or the total thermal load. To an output terminal of blast amount determining means 23 is connected a blower control means 24. The blower control means 24 controls the rotational speed of a blower 5 to control the blast amount so that the amount of the blast within the duct 6 depends on the set pressure. To an output terminal of capability determining means 25, a heat supply apparatus control means 26 is connected, which controls the capability of a heat supply apparatus 17 to control so that the temperature within the duct becomes equal to the set temperature.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This 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, and in particular, to a duct type air conditioner that can adjust the air blowing pressure and air temperature. It's about control.

[Conventional technology]

Central air conditioning systems use air ducts to distribute temperature-controlled air to each room for air conditioning (hereinafter referred to as air conditioning), and can easily incorporate humidifiers and high-performance filters, allowing for outside air processing and total heat exchange. It is possible to use a heat pump chiller to achieve high-quality air conditioning, and the room to be air-conditioned has only an air outlet and an inlet, so indoor space can be used effectively and there are fewer problems with the heat transfer system. It has many advantages compared to fan coil systems and packaged air conditioner distribution systems, and is therefore widely used in building air conditioning.Among these, variable air volume control systems (hereinafter referred to as VAV systems) that enable energy-saving operation are used. It is possible to independently control the temperature of each room with a different heat load, it is also possible to stop air conditioning in rooms that are not in use, and it is possible to reduce operating costs by varying the capacity of the blower depending on the amount of air required. Also, by considering the simultaneous usage rate, the capacity of the heat source equipment can be designed to be smaller.

For the above VAV system, there are 2
There are two methods. One is a system using a bypass type VA 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 is a method using an aperture type VA, V 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. (temperature 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.

Conventional technology using a diaphragm type VAV unit includes the
Figure 2 in Publication No. 0-47497 and the Refrigeration and Air Conditioning Handbook (New Edition, 4th Edition, Advanced Edition) published by the Japan Refrigeration Association. 10
(a) is known. FIG. 4 is a system configuration diagram of these conventional air conditioners. In the same figure, 1
is a room to be air-conditioned, and here the case of four rooms is shown. 2 is an indoor unit placed in the ceiling of room 1, and air filter 3. Heat exchanger4. It is composed of a blower 5.

6 is a main duct connected to the air outlet of the indoor unit 2, 7 is four ducts branched from this main duct 6 according to the number of rooms, and 8 is a diaphragm type inserted in the middle of this branch duct 7. 9 is a damper rotatably installed in the VA unit 8, IO is an air outlet installed at the end of the duct 7, and 11 is a suction port provided at the bottom of the door of the room 1. , 12 is a ceiling suction port provided on the ceiling of the hallway, 13 is a suction duct that connects this ceiling suction port 12 with the suction port of the indoor unit 2, and 14 is a room temperature detector installed in each of the rooms 1. A room thermostat equipped with a room temperature setting device (both not shown); 15, a temperature detector installed in the main duct 6; 16, a pressure detector also installed in the main duct 6; 17, the heat exchanger This is a heat source device such as a heat pump connected to the device 4.

In the conventional air conditioner configured as described above, the damper 9
Adjust the opening degree of each to the desired position. The pressure inside the main duct 6 changes in accordance with the opening degree of the damper 9, which is detected by the pressure detector 16, and the capacity of the blower 5 is changed so as to reach a preset pressure. In addition, since the air blowing temperature on the outlet side of the heat exchanger 4 changes as the air blowing amount changes, this temperature is detected by the temperature detector 15, and the heat source device 17 has the ability to adjust the air blowing temperature to a preset air temperature. control. 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 IO 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 the suction port 11 through the corridor ring space to the ceiling suction port 12, and returns to the indoor unit 2 via the suction duct 13.

FIG. 5 is a diagram showing how the amount of air passing through the VAV unit is controlled with respect to the cooling load shown in the Refrigeration and Air Conditioning Handbook 2.14. In the figure, the horizontal axis represents the cooling load and the vertical axis represents the air volume, but the cooling load can be replaced with the difference between the current room temperature and the set room temperature, and the air volume can be replaced with the opening degree of the damper 9. As the room temperature decreases due to the cooling operation and the difference from the set room temperature becomes smaller, the damper 9 gradually closes and blows an air volume balanced with the heat load into the room 1 from the air outlet 10.

In addition, in FIG. 5, when the cooling load decreases below a certain value, the air volume is kept constant and the air temperature is controlled to increase as the load decreases. This control is intended to ensure the minimum amount of ventilation in buildings, etc., and is a control that changes the air temperature to accommodate the load while maintaining the minimum amount of air.

The -i VAV system determines the optimal values of the air blowing temperature and air blowing pressure according to the designed heat load, and controls the capacity of the heat source machine and the blower so that these values are approximately constant. However, if there is a room with a particularly large heat load, the room temperature in that room may not reach the set value, and if the heat load is small, excessive pressure may occur, causing problems such as noise generation and blower power not being reduced. was there.

In order to solve these problems, methods have been proposed to variably control the blowing temperature and blowing pressure.

For example, Japanese Patent Publication No. 55-24022, Utility Model Publication No. 56-5
In Publication No. 712, etc., the blowing temperature and blowing pressure are variably controlled in proportion to the outside temperature. Also, JP-A-49-1114
No. 47, Japanese Patent Publication No. 55-44854, etc., the blowing temperature and blowing pressure are variably controlled in proportion to the representative room temperature and the temperature of the return air. Furthermore, in the above-mentioned Japanese Patent Publication No. 60-47497, an air volume sensor is built into the VAV unit, and if the required air volume set by the room thermostat is not satisfied even though one of the dampers is fully opened, the capacity of the fan is adjusted. The air flow rate was increased. Furthermore, in Japanese Patent Application Laid-Open No. 59-32732, the blower capacity is lowered when none of the dampers are fully open, and the blower capacity is increased when one damper receives a signal indicating that it is fully open or higher. In addition, as a method to shorten the time for the room temperature to rise at startup, a control system was introduced in which the heat source equipment and blower are operated at maximum capacity for a certain period of time after startup.
This is proposed in Publication No. 94.

[Problem that the invention seeks to solve]

In an air conditioner using a conventional aperture-type VAV unit as described above, the damper 9 of the VAV unit 8 automatically adjusts the air volume according to the heat load in each room. If the blowout air temperature and duct internal pressure are always controlled to be constant, the capacity may vary even if the damper 9 is fully opened when the heat load is large, depending on how the blowout air temperature and pressure are set. If there is a room where the room temperature does not reach the set value due to insufficient heat, or if the heat load is small, there is a problem in that all dampers are throttled down to reduce the air volume and the operation is operated with a large pressure loss. Therefore, various methods have been proposed to variably control the blowing temperature and blowing pressure.

However, even if the cooling or heating capacity is increased or decreased by controlling the air temperature and air pressure depending on the outside air temperature, the heat load in each room does not change uniformly depending on the internally generated heat or the orientation of the room. It does not necessarily mean that you will be able to drive, and
This control method could not shorten the rise time.

Furthermore, in the case of controlling based on the representative room temperature, the representative room does not represent the heat load of all rooms, and the heat load is not necessarily the maximum. Furthermore, even when the representative room is not in use, the damper there is closed, which can result in uncontrolled air conditioning. When controlling the return air temperature instead of the representative room temperature, the return air temperature does not change much whether there is one room or many rooms being air-conditioned, and in particular, even if the number of air-conditioned rooms decreases, the temperature does not change much, and the overall Does not reflect heat load status. For this reason, optimal control could not be performed. In addition, with the system in which each VAV unit includes an airflow sensor, the price and reliability of the sensor were major obstacles. In the method of operating at maximum capacity for a certain period of time in order to shorten the startup time, it is difficult to set the time; if it is too short, the startup time will be long, and if it is too long, there will be periods of operation at excessive capacity. There was a problem.

This invention was made to solve the above problem.
By setting the optimal air flow rate and air temperature according to the size of the heat load in each room, the rise time is short and the room temperature can be accurately controlled to the set value even when the heat load in some rooms is large. The purpose of the present invention is to provide an air conditioner that can further reduce the power of a blower when the heat load is small, and minimize the number of times the heat source equipment starts and stops.

[Means for solving problems]

The air conditioner according to the present invention includes a heat load measuring means that receives a detection signal from a room thermostat and measures the heat load in each room, and a damper installed in a duct connected to a heat source device based on the measurement result. A damper control means for controlling the degree of opening, and a set pressure and/or a set temperature in the duct based on the maximum heat load or total heat load in each room within a certain period of time measured by the heat load measuring means. Determine the capacity of the blower and the capacity of the heat source device based on the set pressure determining means and the set temperature determining means, and the output of the pressure and temperature measuring means which receives the determination results and the detection signals from the pressure detector and the temperature detector. The apparatus is provided with an air flow rate determining means and a capacity determining means, and a blower control means and a capacity control means for controlling the capacity of the blower and the capacity of the heat source device based on the respective outputs.

[Effect]

In this invention, both or one of the set pressure determining means and the set temperature determining means determines the set values of the blowing pressure and the blowing temperature to a pressure and temperature that are proportional to the maximum heat load or total heat load of each room. However, if there is a room in which the room temperature does not reach the set room temperature even after a certain period of time in this state, the set value will be changed to increase the capacity. This will enable accurate room temperature control during high heat loads. and enables reduction of blower power during low heat loads.

〔Example〕

FIG. 1 is an overall system configuration 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 indoor unit 2, a blower 5 that conveys cold and hot air generated by the heat exchanger 4, and a blower 5 connected to the blower 5. a main duct 6, a damper 9 for adjusting the air flow disposed in a branch duct 7 of the main duct 6, a pressure detector 16 for detecting the pressure inside the main duct 6, and a temperature detector for detecting the air temperature. Vessel 1
5 and a room thermostat 1 installed in each room 1
It is equipped with 4. In addition, each room thermostat 1 above
4 is connected to a heat load measuring means 18, which measures the magnitude of the heat load in each room 1 from the difference between the set temperature signal and the detected temperature signal from each room thermostat 14. The heat load signal is sent to the damper control means 19.
is input. Stepping motors (not shown) are connected to the damper control means 19 to control the opening of each damper 9 separately, and each stepping motor is controlled by a control output signal according to the measured heat load of each room. The opening degree of each damper 9 is controlled according to the heat load. Further, 20 is a set pressure determining means for determining the pressure inside the duct 6 from the value of the maximum heat load or total heat load within a certain period of time in each room 1, and 21 is the same as above, the maximum heat load Alternatively, it is a set temperature determining means that determines the air blowing temperature in the duct 6 from the value of the total heat load, and 22 is the pressure detector 16 and the temperature detector 15.
This is a pressure/temperature measurement means that measures pressure and temperature based on the detection signal of the sensor. Further, 23 is the set pressure determining means 2.
0 and the output signal from the pressure/temperature measuring means 22, and determines the air blowing capacity of the blower 5 based on these signals. is connected, and this blower control means 24 controls the rotational speed of the blower 5 so that the amount of air blown in the duct corresponds to the set pressure. Reference numeral 25 denotes a capacity determining means which inputs the output signals from the set temperature determining means 21 and the pressure/temperature measuring means 22 and determines the capacity of the heat source device 17 based on these signals. is connected to a heat source device control means 26, and this heat source device control means 26 controls the capacity of the heat source device 17 (
In the case of a compressor, by controlling its rotation speed, the temperature inside the duct is controlled to the set temperature.

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

Next, the operation of the above embodiment will be explained during heating with reference to the flowchart in FIG. 2 and the explanatory diagram of set pressure and set temperature in FIG. 3. Note that these controls are realized using a microcomputer, but the circuit is omitted. Further, a detailed explanation of the method for controlling the opening degree of the damper 9 for adjusting the amount of air blown in accordance with the heat load has been omitted.

When the air conditioner is operated for heating, the control program shown in FIG.
The actual room temperature (TR) value is input, and based on this, the opening degree of each damper is determined in step 31. Here, if the room temperature is equal to the set room temperature, the opening degree of the damper 9 is not changed; if the room temperature is low, the damper 9 is opened, and if the room temperature is high, the damper 9 is closed (step 32).

In the next step 33, the room temperature Tl of each room except the non-air conditioned room is
The maximum value of the heat loads determined from the difference between l and each set room temperature T0 is determined. In addition, here, heat load - set room temperature T. - room temperature T. Further, instead of the maximum heat load, the integrated value of the heat loads of each room, that is, the value of the total heat load may be used. In the next step 34, Po −P6 min
Calculate +A (To-D,) and P. seek.

In addition, P.

is a set pressure, P and min are lower limit set pressures (constants) determined within a range in which the blower 5 can operate stably, and A is a constant. In the next step 35, the maximum (To TR)
It is determined whether the value of has been larger than a certain value (for example, Odeg) for a certain period of time (for example, from 5 minutes ago until now), and if it is larger, it means that the capacity is insufficient, so the next step 36 Then, a constant C is added to P, resulting in a new P.

becomes. If rNOJ is determined in step 35, the process proceeds to step 37 following step 36.

Set temperature P. The value of is determined in step 37 by the lower limit setting pressure (P
, min), and if it is, the next step 38 sets P,=Pomin. On the other hand, when the determination result in step 37 is rNOJ, the process moves to step 39 and it is determined whether or not the set pressure P0 exceeds the upper limit set pressure (Pomax). . =Polla
Set as X.

In the next step 41, T=Tmin +B (To−
TR) is calculated to find T. Note that T is a set temperature, T min is a lower limit set temperature (constant) determined in consideration of indoor comfort and characteristics of the heat source device 17, and B is a constant.

In the next step 42, the maximum (
It is determined whether the value of 'ro R8) has been larger than a certain value for a certain period of time, and if it is larger, a constant ri is added to T in the next step 43 to become a new set temperature T.
The timer counter used to determine time is reset to zero. If the determination in step 42 is "NO", the process proceeds to step 44, which follows step 43. The value of the set temperature T is set to the lower limit set temperature (T m1n) in step 44.
It is determined whether the value is below , and if it is,
In step 45, T=Tmin is set. Further, when the determination result in step 44 is "NO", it is determined in step 46 whether or not the set temperature T exceeds the upper limit set temperature (T max), and if it is, step 47
Set T=Tmax.

Step 48 takes in signals from the pressure detector 15 and temperature detector 16, and the current pressure (P) and temperature (T,
). When this process is completed, the process moves to the next step 49, where it is determined whether all dampers 9 are fully closed or close to fully closed, which exceeds the operating limit. It is determined whether the machine 17 is being operated. If it is running, proceed to the next step 52; if it is stopped, the heat source device 17
and step 51 to operate the blower 5.
Proceed to step 2. In step 52, P and P. The values are compared, and if the relationship PG>P, the capacity of the blower 5, that is, the rotation speed r
pm is increased according to the difference between P and Po (step 5
3), if the relationship PG<P, it is brought down (step 54). Further, if P is within the dead zone of Po, the rotation speed is not changed and the process proceeds to the next step 55.

In step 55, the rotational speed of the blower 5 is controlled by a phase controller or the like.

Then, the process moves to the next step 56, where the values of T and T are compared, and if the relationship T > Ts, the capacity of the heat source device 17 (
If the heat source device is a heat pump, the rotation speed of the compressor) is increased according to the difference between T and T (step 57) o
If T < Ts, it is down (step 58
). Further, if T is within the dead zone of T, the rotation speed is not changed and the process proceeds to the next step 59. At step 59, heat is generated due to impark etc. l; +The rotational speed of the machine 17 is controlled. Note that if it is determined in step 49 that all dampers 9 are fully closed, the process advances to step 60, where the blower 5
and stops the heat source device 17.

The above control is repeated at regular time intervals. As a result of this series of controls, if the room temperature in a particular room or multiple rooms is significantly lower than the set room temperature, the set pressure and set temperature values are set high, and even after a certain period of time has passed, the If this is not improved, the set value will be set higher and the heating capacity will be increased. Further, since the opening degree of the damper 9 is also proportional to the magnitude of the heat load, the damper 9 in the room 1 with the maximum heat load is almost fully opened. As a result, high-temperature, large-volume hot air is supplied to the room with the maximum heat load, rapidly raising the room temperature. On the other hand, the damper 9 in the room l where the room temperature is almost satisfied is throttled down to supply an appropriate amount of warm air. Further, when the room temperature of each room l approaches the set room temperature and the value of the maximum heat load or the total heat load becomes small, the values of the set pressure and the set temperature are lowered, and the air flow rate and the air blow temperature are reduced. When the room temperature decreases as the air volume and temperature decrease, each damper 9 operates in the opening direction, and eventually the damper 9 is operated in a nearly fully open state at a low set pressure and set temperature. Therefore, the blower 5 is operated with less pressure loss, and the blower input is reduced. In addition, the heat source equipment 17 has a capacity commensurate with the heat load.
As more cars are being operated, the number of times they start and stop will also decrease.

In addition, in FIG. 3 of the above embodiment, the values of the set pressure (Po) and set temperature (T) were fixed at P6min or Tlll1n from the time when the value of (To To) was zero, but this It doesn't necessarily have to start from zero.

Further, in the above embodiment, the air blowing amount and capacity are controlled by controlling the rotation speed of the blower 5 using a phase controller and the heat source device 17 using an inverter, but this may be done using other control means.

Furthermore, in the above embodiment, the values of the set pressure and temperature are determined based on the maximum heat load (maximum value of set room temperature - room temperature value of each air-conditioned room) or total heat load. The heat load can be determined by measurement at each control timing, at certain intervals, or as an integrated value or average value over a certain period of time.

In addition to the above-described method of controlling the damper 9, in which the opening degree is set proportionally in proportion to the thermal load, there is also a method of controlling the damper 9 to two positions, fully open and fully closed.

Further, in the above embodiment, both the set values of the blowing pressure and the blowing temperature are variably controlled according to the heat load, but only one of them may be variably controlled. In this case, the control integers (A, B), (C) are set so that the capacity variable range is the same as in the above embodiment.

Set the value of D) to a large value.

〔Effect of the invention〕

As described above, according to the present invention, a means is provided for determining the set pressure and temperature in the duct according to the magnitude of the maximum heat load or the total heat load, and based on this determination, the appropriate air flow rate and air temperature are determined. Since it is configured to supply cold and hot air to each room, the room temperature can be accurately controlled to the set value even when the heat load is large, such as during startup, and the blower can be operated with less conveying power when the heat load is small. can.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram showing an embodiment of an air conditioner according to the present invention, Fig. 2 is a flowchart showing the control operation of Fig. 1, and Fig. 3 is an explanatory diagram showing the relationship between heat load and set value. , FIG. 4 is an explanatory diagram of the configuration of a conventional air conditioner, and FIG. 5 is an explanatory diagram showing the relationship between the conventional cooling load and air volume. ■...Room, 5...Blower, 6...Duct, 7...
... Technique 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... Set pressure determining means, 21... Set temperature determining means, 22... Pressure/temperature measuring means, 23... Air blowing amount determining means, 24... Air blower Control means, 25... Capacity determining means, 26... Heat source device control means. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (3)

[Claims] (1) A heat source device with variable capacity to generate hot or cold air, a duct that distributes and supplies cold and hot air from this heat source device to each room, a variable capacity blower, and air volume placed in the branches of the duct. In an air conditioner equipped with a damper for adjustment and a room thermostat installed in each room, the heat load in each room is measured from the difference between the input signals of the room temperature set by the room thermostat and the detected room temperature. damper control means for controlling the opening degree of the damper based on the output of the heat load measuring means; a set pressure determining means for determining a set pressure in the duct based on the value or the value of the total heat load, a set temperature determining means for similarly determining the set value of the air blowing temperature, a pressure detector and a temperature detector in the duct. pressure/temperature measuring means which inputs the detection signal of the above-described pressure/temperature measuring means; air blowing rate determining means which determines the capacity of the blower based on the pressure signal output of the measuring means and the output of the set pressure determining means; and based on the output of the blowing rate determining means. A blower control means for controlling the blower, a capacity determining means for determining the capacity of the heat source machine based on the output of the set temperature determining means and the temperature signal output of the pressure and temperature measuring means, and a capacity of the heat source machine based on the output of the capacity determining means. An air conditioner equipped with a heat source control means for controlling. (2) The set pressure determining means makes the set pressure in the duct proportional to the maximum value of the heat load (temperature difference between the set room temperature and the actual room temperature) or the total heat load of each room, and determines the value of the heat load within a certain period of time. Claim 1, characterized in that the set pressure is corrected to a higher value when the pressure does not become smaller.
Air conditioner as described in section. (3) The set temperature determining means makes the set temperature in the duct proportional to the maximum value or total heat load of each room's heat load (temperature difference between set room temperature and actual room temperature), and determines the value of the heat load within a certain period of time. 2. The air conditioner according to claim 1, wherein the set temperature is modified to increase the capacity when the temperature does not decrease.