JP2001027435A - Method and device for control of heat-exchanging element of rotary type heat-exchanging-ventilating unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the control of a rotary type heat-exchanger in a manner to save energy in a heat-exchanging-ventilating unit for which a rotary type heat- exchanging element is used. SOLUTION: This rotary type heat-exchanging-ventilating unit wherein a ventilation is performed by heat-exchanging the outside air and indoor air, performs the heat- exchange by rotating a heat-exchanging element only when an energy consumed by an air conditioner or the like to generate a quantity of heating which can be recovered by the heat-exchange exceeds an energy required to rotate a heat-exchanging element. A processing air volume of the heat-exchanging element, sensible and latent heat- exchanging efficiencies in the processing air volume, a formula to operate a sensible heat volume and a latent heat volume of air, the energy consumption efficiency of the air conditioner, an energy required to rotatively drive the heat-exchanging element, and control procedures for the heat-exchanging element are stored in a memory section. Then, the controls of all the heat-exchangers are performed by reading the control procedures from the memory section by a central operation device, and by a signal which is output from the central operation device, contact points are made/to open or close to rotate or stop all the heat-exchanging elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the control of a heat exchange element of a heat exchange ventilation unit using a rotary heat exchange element used for ventilation of an indoor space such as a living room.

[0002]

2. Description of the Related Art A rotary heat exchange ventilation unit used for ventilation stores and releases heat by using a heat exchange element as a medium when ventilating, so that the outside air and return air discharged from a space to be ventilated can be removed. It exchanges temperature and humidity between the two, recovering the heat of the return air and helping to save energy required for air conditioning. FIG. 2 schematically shows this structure. A cylindrical heat exchange element having a regenerator honeycomb-shaped cross section is provided. A substantially half of the circular cross section has an outside air inlet and an air supply port of a space to be ventilated. And is rotatable in the circumferential direction so that the other half is located in the air path on the exhaust side that passes through the return port and exhaust port of the space to be ventilated. And heat is recovered by rotating it using an electric motor or the like. That is, in order to recover heat, energy for rotating the heat exchange element is required.

[0003]

Conventionally, such control of operation / stop of the heat exchange element has been conventionally performed by a person operating a switch.
It is performed by a method such as an automatic control operation based on the outside air temperature or an interlocking operation with an air conditioner for cooling and heating, but has the following problems. For one, none of the methods compare the amount of energy consumed by an air conditioner or the like with the energy required to rotationally drive the heat exchange element in order to generate heat that can be recovered, That is, the heat exchange element is driven to rotate without confirming whether energy can be saved. Second, the interlocking operation with the air conditioner is better than the other two methods from the viewpoint of energy saving, but it cannot be realized without the commonality of signals.

As described above, a heat exchange ventilation unit using a rotary heat exchange element consumes a considerable amount of energy to rotate the heat exchange element. Therefore, in order to control the rotary heat exchanger so that energy can be saved, the energy required for the air conditioner to generate heat that can be recovered by heat exchange and the energy required for rotating the heat exchange element must be reduced. In comparison, it is better to rotate the heat exchange element only when the energy required by the air conditioner is large. However, as described above, the conventional operation / stop control of the heat exchange element is performed by human judgment, judgment based on the outside air temperature, or interlocking with the air conditioner, etc., as described above.
No comparison has been made between the energy consumed by the air conditioner or the like to generate the amount of heat that can be recovered and the energy used to rotate the heat exchange element, and there is room for improvement in terms of energy saving.

[0005]

SUMMARY OF THE INVENTION According to the present invention, in a rotary heat exchange ventilation unit for performing ventilation by exchanging heat between outside air and room air, energy required for generating heat that can be recovered by heat exchange is heat. Only when the energy required to rotate the exchange element becomes larger than that required, the heat exchange element is rotated to perform heat exchange.

Further, as a control device for implementing this control method, a temperature detector for detecting the temperature of the return air from the room to be ventilated, a humidity detector for detecting the humidity, an air flow rate of the heat exchange element, and the like. A formula for calculating the sensible heat and latent heat exchange efficiency of the heat exchange element, the sensible heat quantity and latent heat quantity of air at this processing air amount, the energy consumption efficiency of the air conditioner, and the energy and heat required for driving the heat exchange element to rotate. A storage unit for storing the control procedure of the exchange element, a central processing unit that reads out the control procedure from the storage unit and controls the total heat exchanger, and opens and closes contacts by a signal output from the central processing unit Then, a control device for the heat exchange element of the rotary heat exchange ventilation unit, comprising a motor switch for rotating or stopping the total heat exchange element, was created.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flowchart showing a control procedure of a heat exchange element of a rotary heat exchange ventilation unit showing an embodiment of the present invention. S1 is a step of checking whether or not the heat exchange ventilation unit is performing a ventilation operation. If the ventilation operation is not being performed, the heat exchange ventilation unit circulates this portion until the ventilation operation is started, and if the ventilation operation is being performed, Goes to S2.

In steps S2 to S5, the outside air temperature (S2), the outside air temperature (S3), and the return air temperature (S4)
And the return air humidity (S5) are detected. In this example, the relative humidity is detected as the humidity, and the following description conforms to this. Subsequently, in steps S6 to S9, the pre-stored processing air amount of the heat exchange element, arithmetic expressions of sensible heat and latent heat, and the values of the temperature and humidity detected in steps S2 to S5 are used. , The sensible heat (S6) and latent heat (S7) of the outside air, and the sensible heat (S8) and latent heat (S9) of the return air are calculated.

The sensible heat of the outside air and the return air is obtained by substituting the dry-bulb temperature of the outside air or the return air and the amount of air processed by the heat exchange element into Equation 1. t is the Celsius temperature (° C.), r is the specific gravity of air (about 1.2 kg / m ³ , Q is the amount of air processed by the total heat exchanger m ³ /
h and hda are sensible heat amounts kj / h.

[0010]

[Equation 1] hda = 1.006? t? r? Q

The latent heat of the outside air and the return air is calculated by first calculating the saturated vapor pressure at that temperature from the detected dry-bulb temperature.
, And then substitute the saturated vapor pressure and the detected relative humidity obtained by Equation 2 into Equation 3 to calculate the vapor pressure, and further substitute the obtained vapor pressure into Equation 4. The absolute humidity is obtained, and the obtained absolute humidity and the amount of air to be processed by the heat exchange element are substituted into Expression 5 to obtain the absolute humidity.

[0012]

Ln (ews) = − 6096.9385T ⁻¹ +21.2409642
−2.711193 × 10 ⁻² T + 1.673952 × 10 ⁻⁵ T ² +2.433502
ln (T) ews: Saturated vapor pressure of water at absolute temperature T T: Absolute temperature K

[0013]

Ew = φ / 100 · ews ew: vapor pressure Pa φ: relative humidity%

[0014]

X = 0.622 ew / P-ew x: Absolute humidity kg / kg (DA)

[0015]

Hwa = (1.805t + 2501) x · r · Q hwa: latent heat kJ / h

In S10, a sensible heat amount that can be recovered is obtained by multiplying the difference between the sensible heat amount of the outside air obtained in S6 and the sensible heat amount of the return air obtained in S8 by a sensible heat exchange efficiency stored in advance. Subsequently, at S11, the latent heat amount that can be recovered is obtained by multiplying the difference between the latent heat amount of the outside air obtained at S7 and the latent heat amount of the return air obtained at S9 by a latent heat exchange efficiency stored in advance. In S12, the sensible heat amount obtained in S10 and the latent heat amount obtained in S11 are added to obtain the total heat amount that can be recovered when the heat exchange element is operated.

In step S13, the previously stored energy required for rotating the heat exchange element is compared with a value obtained by converting the amount of heat that can be recovered obtained in step S12 into the energy of an air conditioner or the like, and the amount of energy that can be recovered is large. In this case, proceed to S14 to close the contacts of the switch of the drive motor of the heat exchange element,
If not, the process proceeds to S15 to open the contacts of the switch. After the completion of both steps, the process returns to S1.

FIG. 3 shows a configuration of a control circuit of the heat exchange element of the rotary heat exchange ventilation unit according to the present invention. The heat exchange element 1 having a cylindrical shape having a cross section in the form of a heat storage body is provided in such a manner that substantially half of the circular cross section is located in the air passage on the air supply side passing through the outside air intake and the air supply port of the space to be ventilated. Of the space to be ventilated is supported in a circumferentially rotatable manner so as to be positioned in the air passage on the exhaust side passing through the return air port and the exhaust port of the space to be ventilated. Then, heat is recovered. The supply air blower 3 and the exhaust blower 4 supply air from the ventilation unit to the room to be ventilated via the supply air passage 5 and exhaust air to the outside via the exhaust air passage 8. On the other hand, the outside air flows into the unit through the outside air passage 7 due to the negative pressure, and the return air from the room to be ventilated is also introduced into the unit through the return air passage 6. The above configuration is within the category of the prior art.

A temperature detector 9 for detecting the temperature of the return air from the room to be ventilated is disposed between the return air passage and the heat exchange element 1. As the temperature detector 9, a thermistor sensor or the like is used. At the same place, a humidity detector 10 for detecting the humidity of the return air is provided, and in this example, the relative humidity is detected. In order to detect the temperature and humidity of the outside air introduced into the other unit, a temperature detector 11 and a humidity detector 12 are arranged between the outside air passage 7 and the heat exchange element 1.

The storage unit 13 stores a processing air volume of the heat exchange element to be controlled, a sensible heat exchange efficiency and a latent heat exchange efficiency of the heat exchange element at the processing air flow, an arithmetic expression of sensible heat and latent heat of air, The program stores the amount of energy required for rotationally driving the element, the energy consumption efficiency of the air conditioner and the like, the control procedure of the heat exchange element shown in FIG. 1, and the like.

The central processing unit 14 reads out a control program for the heat exchange element from the storage device 13 and executes it. The central processing unit 14 reads signals from the return air temperature detector 9, the return air humidity detector 10, the outside air temperature detector 11, and the outside air temperature and humidity detector 12, and reads the sensible heat and latent heat of air read from the storage device. Calculate the energy of the air conditioner required to generate the amount of heat that can be recovered from the return air when the heat exchange element is rotationally driven from the sensible heat exchange efficiency and latent heat exchange efficiency of the heat exchange element. And an energy for rotating the heat exchange element, and a switch 15 for supplying electricity to the electric motor for rotating the heat exchange element when the energy required for the air conditioner is large.
The signal which closes is output.

[0022]

The control of the heat exchange element according to the present invention measures the temperature and humidity of the return air and the temperature and humidity of the outside air, calculates the sensible heat and latent heat of each air, and calculates the heat exchange efficiency of the heat exchange element. The heat exchange element is driven to rotate only when the energy of the air conditioner, etc. necessary to generate the amount of heat that can be recovered when the heat exchange element is operated is greater than the energy required to drive the heat exchange element, taking into account the processing air volume I tried to make it
Energy saving can be reliably achieved as compared with the case where the heat exchange element is always driven to rotate. At the same time, the control section of the heat exchange element can properly judge the heat exchange return air and normal return air, so there is no need to link with the air conditioner, there is no need to worry about the commonality of control signals, and special wiring There is no need for construction.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method of controlling a heat exchange element of a rotary total heat exchanger according to the present invention.

FIG. 2 schematically shows a use state of the rotary total heat exchanger.

FIG. 3 shows a control device of the heat exchange element of the rotary total heat exchanger according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heat exchange element 2 electric motor 3 supply air blower 4 exhaust blower 5 supply air path 6 return air path 7 outside air path 8 exhaust air path 9 return air temperature detector 10 return air humidity detector 11 outside air temperature detector 12 outside air humidity detection Device 13 Storage device 14 Central processing unit 15 Switch 16 Power supply device 17 Control device

Claims (2)

[Claims] In a rotary heat exchange ventilation unit that performs ventilation by exchanging heat between outside air and indoor air, energy consumed by an air conditioner or the like to generate heat that can be recovered by heat exchange uses a heat exchange element. A method for controlling a heat exchange element of a rotary heat exchange ventilation unit, characterized in that the heat exchange element is rotated to perform heat exchange only when the energy required for the rotation is greater than the energy required for the rotation. 2. A temperature detector for detecting a temperature of return air from a room to be ventilated, a humidity detector for detecting humidity, a temperature detector for detecting a temperature of outside air, a humidity detector for detecting humidity, and a heat detector. A formula for calculating the processing air amount of the exchange element, the sensible heat and latent heat exchange efficiency of the heat exchange element at this processing air amount, the sensible heat amount and latent heat amount of the air, the energy consumption efficiency of the air conditioner, and rotationally driving the heat exchange element. A storage unit for storing a control procedure of energy and a heat exchange element necessary for the operation, a central processing unit that reads out the control procedure from the storage unit and controls the total heat exchanger, and an output from the central processing unit. A control device for a heat exchange element of a rotary heat exchange ventilation unit, comprising a switch of an electric motor for opening or closing a contact in response to a signal to rotate or stop the total heat exchange element.