JPH0621701B2 - Heat exchanger control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a heat exchanger that controls by using enthalpy as a control parameter.

2. Description of the Related Art One of conventional control devices of this type is an enthalpy controller. This enthalpy controller outputs control signals for sensible heat exchange and outside air introduction, or total heat exchange and outside air introduction, depending on the magnitude of the indoor and outdoor enthalpies as control parameters.

Problems to be Solved by the Invention However, during cooling, when the enthalpy value and the dry-bulb temperature of the outside air are smaller than the enthalpy value and the dry-bulb temperature at the point R as shown in FIG.
The enthalpy value of the outside air is smaller than the enthalpy value at point R,
When the dry-bulb temperature of the outside air is higher than the R point, sensible heat exchange is performed, and when the enthalpy value of the outside air is higher than the R point, total heat exchange is performed between the room and the outside air to lower the enthalpy value of the outside air and introduce the outside air. Three modes are possible. Also during heating, as shown in Fig. 3b, outside air is introduced, sensible heat is exchanged,
It is conceivable to use three modes of total heat exchange. Therefore, the conventional heat exchanger control device was controlled only by the enthalpy, and it was not suitable for energy saving because it was not possible to perform detailed control closely related to the region and climate.

The present invention solves the above problems, and an object of the present invention is to provide a heat exchanger control device capable of performing detailed control closely related to the region and climate and suitable for energy saving.

Means for Solving the Problems In order to solve the above problems, the heat exchanger control device of the present invention has an indoor temperature, a temperature for converting humidity to a signal, and a humidity signal output unit, and an outdoor temperature and humidity. And a temperature and humidity signal output unit for converting the signal into a signal, a calculator that inputs the indoor and outdoor temperature and humidity signals, calculates the enthalpy of the room and outputs the enthalpy as a signal, and this enthalpy signal, and This is a configuration provided with an output device that compares the temperature signals from the temperature signal output section indoors and outdoors and outputs control signals for sensible heat exchange, total heat exchange, and outside air introduction.

The present invention has the above-mentioned configuration, and obtains the indoor and outdoor enthalpies using the arithmetic unit, and the output device introduces the outside air due to the indoor and outdoor enthalpy difference and the indoor and outdoor sensible heat difference from the temperature signal output unit. Since the control signals for the three ventilation modes of sensible heat exchange and total heat exchange are output, it is possible to realize energy saving throughout the year.

Embodiment FIG. 1 is a block diagram showing an embodiment of the heat exchanger control device of the present invention. In FIG. 1, 1 is a temperature signal output unit for converting the indoor temperature into an electric signal, 2 is a humidity signal output unit for exchanging indoor humidity with an electric signal, and similarly, 3 and 4 are temperature signal output units for the outside air, respectively. And a humidity signal output unit. 5
Is an indoor enthalpy calculator, and has two input terminals 5
The voltage signals of 1, 52 are calculated to obtain the enthalpy signal output at the output terminal 53. Similarly, 6 is an enthalpy calculator for the outside air, which calculates the voltage signals at the two input terminals 61 and 62 to obtain the enthalpy signal output at the output terminal 63. Reference numeral 7 is a comparator, which is turned on according to the voltage difference between the two input terminals 71 and 72,
The OFF signal output is obtained from the output terminal 73. Similarly, 8 is a comparator which obtains an on / off signal output from an output terminal 83 in accordance with a voltage difference between two input terminals 81 and 82. Reference numeral 9 is a condition discriminator, which is composed of a plurality of 2-input NAND circuits combined with each other. Reference numeral 10 is a control signal output unit of the heat exchanger. An output device 11 is constituted by the comparators 7 and 8, the condition discriminator 9, and the signal unit 9.

In the above configuration, the temperature and humidity in the room are converted into electric signals by the temperature signal output unit 1 and the humidity signal output unit 2, respectively, and further input into the input terminals 51 and 52 of the computing unit 5 to be converted into electric signals of enthalpy in the room. To be converted. Similarly,
The temperature and humidity of the outside air are converted into electric signals by the temperature signal output unit 3 and the humidity signal output unit 4, respectively, and further input into the arithmetic unit 6 to be converted into enthalpy electric signals.

The indoor and outdoor enthalpy signals and the temperature signal thus obtained are respectively sent to the comparators 7 and 8 in the next stage, and are converted into ON and OFF signals according to their magnitude relationship. The output signals of the comparators 7 and 8 are sent to the condition discriminator 9, and as shown in FIG. 3, the following three ventilation modes, that is, introduction of outside air and sensible heat, are performed according to the enthalpy difference between the indoor and outdoor temperatures Control signals for exchange and total heat exchange are output from the signal output unit 10.

Next, another embodiment of the present invention will be described. By the way, it is known that the enthalpy is approximately represented by the following equation. That is, i = a (t + p) (+ q) + r (1) Here, t: dry bulb temperature ,: relative humidity, a, p, q, r: constants.

Now, the constants a, p, q, and r are defined as follows, and 20t
When the enthalpy is calculated from (1) in the range of 30 ° C and 10 to 90% RH, and the difference from the enthalpy obtained by the conventional equation of state of saturated vapor pressure is calculated, as shown in the table, max 0.5 kcal / k
It can be approximated with the precision of g '.

a = 7.6163 × 10 ⁻³ p = 2.21189 × 10 ⁻³ q = 30.21 r = 0.16124 Therefore, if the equation (1) is used, the indoor and outdoor enthalpy computing unit is a multiplier of an electrical signal represented by a linear function of indoor and outdoor temperatures and an electrical signal represented by a linear function of indoor and outdoor relative humidity, and It is possible to create an arithmetic unit configured by an adder with a constant signal and outputting the indoor and outdoor enthalpy i as a signal.

FIG. 2 shows another embodiment of the present invention. In FIG. 2, 4 is a humidity signal output unit, and 401 is a humidity sensor including a resistor 402 that detects a humidity change as a resistance change. The voltage value of the terminal 403 is a value obtained by dividing the voltage applied to the terminal 404 by the ratio of the humidity sensor 401 and the resistance 405, and a linear function of the relative humidity is constituted by this, and the humidity signal is output. Reference numeral 6 denotes an outside air enthalpy calculation unit, which is connected to the terminal 403 at the inverting input terminal of the operational amplifier 602.
Voltage is output to the terminal 604 according to the amplification degree determined by the resistor 603 and the temperature sensor 601 in which the resistance is represented by a linear function of temperature.
Here, the output voltage of the terminal 304 is a product of a linear function having a relative humidity as a variable and a linear function having a temperature as a variable. Further, by using the operational amplifier 607 as an adder and adding the voltage of the terminal 604 and the voltage of the terminal 606, an enthalpy voltage signal output is obtained at the terminal 607. By processing the enthalpy signal in the same manner as in the above embodiment as shown in FIG. 3, three control signals are output to the signal output section in accordance with the indoor and outdoor temperature and humidity conditions.

As described above, according to the present invention, as is apparent from the examples, the enthalpy can be obtained from the indoor and outdoor temperature and humidity with a very simple arithmetic unit, and the outside air introduction and exposure can be performed from the respective temperature and enthalpy differences. Three ventilation modes, heat exchange and total heat exchange, can be set, enabling energy-saving operation of the heat exchanger throughout the year regardless of regional characteristics and climate.

[Brief description of drawings]

FIG. 1 is a block diagram showing a heat exchanger control device according to one embodiment of the present invention, FIG. 2 is a block diagram of a heat exchanger control device according to another embodiment of the present invention, and FIG. 3 is an indoor / outdoor temperature. It is a relationship diagram of a humidity condition and three control modes of a heat exchanger. 1, 3 ... Temperature signal output section, 2, 4 ... Humidity signal output section, 5, 6 ... Calculation section, 7, 8 ... Comparator, 9 ... Condition discriminator, 10 ... Signal output section, 11 ... Output device.

Claims (3)

[Claims] 1. An indoor temperature and indoor humidity signal output unit for converting indoor temperature and humidity into signals, an outdoor temperature and outdoor humidity signal output unit for converting outdoor temperature and humidity into signals, and
A calculator that inputs these indoor and outdoor temperature and humidity signals, calculates the indoor and outdoor enthalpy, and outputs the enthalpy as a signal. The enthalpy signal and the temperature signal from the temperature signal output section are used indoors and outdoors, respectively. In comparison, a heat exchanger control device including an output device that outputs a control signal that determines whether to control sensible heat exchange, total heat exchange, or external air introduction ventilation mode for controlling the introduced outside air and the exhaust air from the room . 2. The heat exchanger control device according to claim 1, wherein electric signals are used as the temperature, humidity, enthalpy, and control signals. 3. An indoor / outdoor humidity signal output section is a relative humidity signal voltage output section expressed by a linear function having a relative humidity as a variable, and an indoor / outdoor temperature signal output section is expressed as a linear function having a temperature as a variable. The heat exchanger according to claim 1, wherein a thickening device that changes a broadening degree by a resistance is used, and the computing device is a computing device that multiplies the relative humidity signal voltage output section and the output signal of the thickening device. Control device.