JPS62202957A - Control device for rotational speed of air handling unit - Google Patents

Abstract

PURPOSE:To prevent vibration to various devices and members which are installed in a box with a simple construction by comparing and judging outputs from a VVVF (Variable Voltage, Variable frequency) operation amount calculating means and the outputs from a VVVF skip setting means and controlling a blower based on this comparison and judgement. CONSTITUTION:The temperature of a space to be air-conditioned is measured and an amount of operation is calculated based on a temperature target value for the space to be air-conditioned which has been beforehand set up. A skip width of DELTAmV is provided in front of and at the rear of each of resonance points A, B and C which have been determined beforehand by measurement and for control outputs of the VVVF which come in this skip width they are controlled so that the ratio of the rotational speed of a blower is constant. With this arrangement it is possible to change the control outputs of the VVVF and avoid the operation at the resonance points.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air handling unit rotation speed control device installed in offices, buildings, etc.

2. Description of the Related Art Conventionally, this type of air handling unit rotation speed control device has been constructed as shown in FIG.

That is, a blower 2. A heat exchanger 104 and a filter 106 are provided, and a vibration isolator 103 that absorbs vibrations from the blower 102 is provided between the installation part and the cylinder 101.

A temperature detector 106 for measuring the temperature is provided in the air-conditioned space 107 that receives air from the air handling unit, and a temperature signal from the temperature detector 106 is input to the temperature measuring means 108. Based on the temperature deviation amount obtained from the air-conditioned space temperature setting means 109, VVVF (Variable Voltage
, Variable Frequency) The manipulated variable determination means 110 determines the manipulated variable of VVVF, and
The output from the VVF operation amount determining means 110 is given to the VVVF driving means 111, and based on this, the rotation speed (air volume) of the blower 102 of the air handling unit is controlled.

The air handling unit rotation speed control device with this configuration outputs a control output from 0 to VVVF as shown in FIG.
10V, the blower rotation speed ratio was also controlled to have a directly proportional characteristic of 0 to 100%.

Problems to be Solved by the Invention In the conventional air handling unit rotation speed control device, there are several resonance points between the blower 102 and the casing 101 within the rotation speed control output range. A vibration isolation material 103 is provided between the building and the casing 101 so that resonance vibrations are not transmitted to the building. However, like the blower 1o2, the heat exchanger 10 is installed inside the housing 1o1.
Because it is difficult to install vibration isolators for 4° piping (not shown), flow rate control valves (not shown), etc. due to their construction, it is difficult to provide squeaks due to vibration and the reliability and durability of equipment against vibration. The problem was that sufficient measures had not been taken.

The present invention takes these problems into consideration and aims to provide an air handling unit rotation speed control device that has an extremely simple configuration and can also prevent vibrations to the nine members of each device installed inside the housing. It is something.

Means for Solving the Problem In order to solve this problem, the present invention measures and sets the resonance point that occurs between the blower and the casing in advance (it has a VVVF skip setting means, and the VVVF operation Comparing and determining the output from the quantity calculation means and the output from the VVVF skip setting means, and determining the output to the VVVF;
The blower is controlled based on this.

The function is determined by actually measuring the resonance point that occurs between the blower and the housing through a test run of the blower, and based on the results, the skip band is set so that the control output of the VVVF at the point where the resonance occurs is not used. The VVVF skip setting means to be set is compared with the 1VVVF output determining means, and if the output value from the VVVF operation calculation amount calculation means is within the VVVF skip setting, the skipped output is sent to the VVVF driving means and the blower is activated. By driving, operation at the resonance point is avoided.

Example An embodiment of the present invention will be described below with reference to FIG.

In the figure, 1 is the housing of the air handling unit, 2 is the blower, 3 is the vibration isolating material that absorbs vibrations from the blower 2, and 4
6 is a heat exchanger, 6 is a filter, 6 is a temperature detector that measures the temperature of the air-conditioned space 7, 8 is a temperature measuring means for inputting the temperature signal from the temperature sensor 6, and 9 is a temperature target for the air-conditioned space 7 This is an air-conditioned space temperature setting means for setting a value, and since these are configured similarly to the conventional ones described above, a description thereof will be omitted. This embodiment is characterized by the provision of a VVVF operation amount calculation means 12 for calculating the operation amount of the VVVF based on the temperature deviation amount from the temperature measurement means 8 and the conditioned space temperature setting means 9, and a A resonance point that occurs between VVVF and VVVF is set in advance (VVVF skip setting means 13 is provided, and the output from the VVVF operation amount calculation means 12 and VVVF skip setting means 13 is
The VVF output determining means 14 compares and determines the output to the VVVF, and the VVVF driving means 11 controls the blower 2 based on the output from the VVVF output determining means 14.

Next, the operation of the air handling unit rotation speed control device configured as described above will be explained using the flowchart shown in FIG. When the air handling unit is activated, the operation of the VVVF is started according to the means of the VVVF operation program shown in the flowchart of FIG. 2 stored in the ROM (Read Only Memory).

First, the temperature of the air-conditioned space 7 is measured in the temperature measurement process of step 2o. Next, the PI is calculated based on the temperature target value of the air-conditioned space 7 set in advance in the VVVF operation amount calculation process in step 21 and the temperature measured in step 2°.
Calculate the amount of operation to VVVF using an arithmetic expression. In the skip determination process in step 22, the VVV in step 21 is
Determine whether the output obtained by the F operation amount calculation process is within the preset skip medium thickness,
If there is that output in the skip medium meat, move to step 23 V
The output to VVF is the output before entering the skip width.
Send to. When the output is other than the skip width, the process moves to step 24, and the value is updated to the value calculated and output in step 21, and the output is sent to the VVVF.

Next, according to the VVVF characteristic graph in Figure 3, the actual VVVF
To explain the operating output characteristics of
A skip width of JmV is provided before and after the skip width, and the blower rotation speed ratio is controlled to be constant for the VVVF control output entered into the skip.

As described above, according to this embodiment, by providing the skip width ΔmV in the VVVF skip setting means, V
By changing the control output of the VVF, operation at the resonance point can be avoided.

Effects of the Invention As described above, according to the present invention, it is possible to eliminate the resonance occurring between the blower and the housing with an extremely simple configuration of providing the VVVF skip width ΔmV, and also to eliminate the resonance that occurs between the blower and the housing. It is also possible to prevent the adverse effects of vibration on the equipment and components being used, and a very useful effect can be obtained from a practical standpoint.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an air handling unit rotation speed control device according to an embodiment of the present invention, FIG. 2 is a flowchart showing an example of an operation program of the air handling unit rotation speed control device, and FIG. FIG. 4 is a configuration diagram showing a conventional air handling unit rotation speed control device, and FIG. 6 is a VVVF characteristic graph of the air handling unit rotation speed control device. 1... Housing, 2... Blower, 6...
...Temperature detector, 7...Air conditioned space, 8...
...Temperature measuring means, 9...Air-conditioned space temperature setting means, 11...VVVF driving means, speech 2.
...VVVF operation amount calculation means, 13...
VVVF skip setting means, 14...VVVF
Output determining means. Name of agent: Patent attorney Toshio Nakao and 1 other person6-
Whisper

Claims (1)

[Claims] a temperature detector that detects the temperature of the conditioned space; a temperature measuring device that measures the temperature detected by the temperature sensor as an input signal; and a conditioned space temperature setting device that sets a temperature target value of the conditioned space; VVVF (Var
iable Voltage, Variable Fr
VVVF operation amount calculation means for calculating the operation amount of the VVVF operation amount calculation means; VVVF skip setting means for previously measuring and setting the resonance point that occurs between the blower and the housing; VV
VVV is determined by comparing with the output from the VF skip setting means.
VVVF output determining means for determining the output to V;
An air handling unit rotation speed control device comprising a VVVF drive means for controlling a blower based on an output from a VVF output determination means.