The present disclosure relates to a heating control device and heating control program for performing heating control of air humidified by a humidifying element.
In a conventional air conditioning system, a ventilation device system and an indoor unit system each have a refrigerating cycle. A ventilation device of the ventilation device system performs operation of supplying outdoor fresh air to the interior. When enthalpy of air introduced from outside air is higher than enthalpy of indoor air, the load is a cooling load. In the case of the cooling load, outdoor air may be cooled by the ventilation device and introduced to the interior. On the other hand, when enthalpy of air introduced from outside air is lower than enthalpy of indoor air, the load is a heating load. In the case of the heating load, outdoor air may be heated by the ventilation device and introduced to the interior.
The refrigerating cycle of the indoor unit system is configured of a compressor, a four-way valve, an outdoor heat exchanger, expansion means, and an indoor heat exchanger. The refrigerating cycle of the ventilation device system is configured of a compressor, a four-way valve, an outdoor heat exchanger, expansion means, and a heat exchanger for the ventilation device. The refrigerating cycles of the indoor unit system and the ventilation device system are filled with a refrigerant. At the time of cooling, the refrigerant compressed by the compressor becomes a gas refrigerant at high temperature and high pressure, and is sent to the outdoor heat exchanger. The refrigerant flowing into the outdoor heat exchanger is liquefied by emitting heat to air. The liquefied refrigerant is decompressed by the expansion means to become in a gas-liquid two phase state, and is gasified by absorbing heat from ambient air by the indoor heat exchanger or the heat exchanger for the ventilation device. On the other hand, air is deprived of heat and thus becomes cooled air to cool an indoor space. The gasified refrigerant returns to the compressor.
At the time of heating, the refrigerant compressed by the compressor becomes a gas refrigerant at high temperature and high pressure, and is sent to the indoor heat exchanger or the heat exchanger for the ventilation device. The refrigerant flowing into the indoor heat exchanger or the heat exchanger for the ventilation device is liquefied by emitting heat to air. On the other hand, air is provided with heat and thus becomes heated air. The liquefied refrigerant is decompressed by the expansion means to become a gas-liquid two phase state, and is gasified by absorbing heat from ambient air by the outdoor heat exchanger. The gasified refrigerant returns to the compressor. Air heated by the indoor heat exchanger is supplied as it is to an air conditioning space to heat the space. Air heated by the heat exchanger for the ventilation device passes through a humidifying element installed on a leeward side to become humidified air, which is supplied to the air conditioning space to humidify the space.
As prior art, there is a technique of adjusting the amount of heating in a heat exchanger for a ventilation device in accordance with the temperature of indoor air so that the indoor temperature is not excessively increased and adjusting bypass air quantity inside the ventilation device in accordance with indoor humidity (for example, Patent Literature 1).
Patent Literature 1: WO 2019/008694 pamphlet
In conventional technologies, heating control is not performed on outside air flowing into the ventilation device based on the degree of the latent heat load of air in the air conditioning space. Thus, even if the latent heat load is small and the amount of heating is not required to be large, outside air is heated by the heat exchanger for the ventilation device with a larger amount of heating than a necessary amount of heating, and energy losses are produced.
The present disclosure is to provide a heating control device which performs heating control on outside air flowing into a ventilation device in accordance with the latent heat load of air in an air conditioning space.
A heating control device according to the present invention includes:
an estimating unit to estimate a latent heat load of air present in a ventilation target space as a ventilation target; and
a heating control unit to control a temperature of outside air heated by a heater, the outside air being supplied to the ventilation target space, in accordance with the estimated latent heat load.
Since the heating control device of the present disclosure includes the estimating unit and the heating control unit, heating control can be performed on outside air flowing into the ventilation device in accordance with the latent heat load of air in the air conditioning space. Thus, according to the heating control device of the present disclosure, energy saving can be achieved when outside air is heated by the heat exchanger for the ventilation device.
An embodiment is described below by using the drawings. Note that identical or corresponding portions in the respective drawings are provided with the same reference characters. In the description of the embodiment, description of identical or corresponding portions is omitted or simplified as appropriate.
<First Refrigerant System 11>
<Second Refrigerant System 21>
<Ventilation Device 210>
<Heating Control Device 700>
As illustrated in
Regarding outside air heated at the heat exchanger 26, that is, outside air at P2 in
A method of adjusting the amount of humidifying outside air by the humidifying element 213 is described. The amount of humidifying outside air by the humidifying element 213 is required to be adjusted so as to be equal to a latent heat load. Here, the latent heat load is a humidifying load with respect to air of the interior 500. Alternatively, the latent heat load is the amount of humidification required to maintain the humidity of the interior 500 at a target value. That is, the following expression 1 holds.
Latent heat load=humidification load=the amount of humidification required to maintain the indoor humidity at a target value (1)
An estimating unit 711 described below estimates a latent heat load for achieving a target absolute humidity X0 of the interior 500 set by the temperature/humidity setting device 520. A heating control unit 712 described below controls the condensation temperature of the refrigerant in the heat exchanger 26 in accordance with the latent heat load estimated by the estimating unit 711. In the heating control device 700, the latent heat load, that is, the amount of humidification for achieving the target absolute humidity X0 of the interior 500, is estimated by the following expression 2. The estimating unit 711 estimates a difference ΔX between the target absolute humidity X0 and an absolute humidity Xi of the current interior detected by the indoor humidity sensor 501 as a latent heat load.
That is,
X0−Xi=ΔX (2)
In the following, the latent heat load is described as ΔX based on expression 1. In the following, the latent heat load may be denoted as a latent heat load ΔX.
<X1 Determination Method>
A method of determining X1 in
<Method of Determining CTmax and CTmin>
A method of determining the condensation temperature CTmax and the condensation temperature CTmin in
In the following example, the outside air condition is assumed to be the outside air temperature. Regarding an outside air temperature T1 and an outside air temperature T2, the outside air temperature T2 is assumed to be higher than the outside air temperature T1.
That is, it is assumed that
T2>T1.
It is assumed that at the outside air temperature T1,
[CTmax, CTmin]=[CTmax1, CTmin1] and
at the outside air temperature T2,
[CTmax, CTmin]=[CTmax2, CTmin2].
Since T2>T1, a relation holds in which
CTmax1>CTmax2
and
CTmin1>CTmin2.
In the above-described [CTmax, CTmin] determination method, the [CTmax, CTmin] determination method when the outside air condition is varied is described. In the following, a method is described in which CTmax and CTmin are determined in consideration of the number of people who are present in the interior 500. First, CTmax can be determined as follows. In a certain outside air humidity condition, when there are as many people in the interior 500 as a designed number of people who are present indoors, CTmax is determined as a condensation temperature which ensures a necessary latent heat load. On the other hand, CTmin can be determined as follows. In a certain outside air humidity condition, when there are a few number of people, for example, when no one is present in the interior 500, CTmin is determined as a condensation temperature which ensures a necessary latent heat load. In this manner, [CTmax, CTmin] is determined in accordance with the number of people who are present indoors. With this method of determining the condensation temperature CTmax and the condensation temperature CTmin, a range in which shortage of humidification or excessive humidification does not occur can be determined for each outside air condition. Thus, comfortability and energy-saving can be ensured.
As illustrated in
Thus, the heating control unit 712 has an energy-saving priority mode and a blowout-temperature priority mode, and changes control operation depending on which mode the user selects. The temperature/humidity setting device 520 has a mode selection function of allowing the user to select either of the energy-saving priority mode and the blowout-temperature priority mode. When the user selects either mode by using the temperature/humidity setting device 520, the heating control unit 712 detects the selected mode.
When the energy-saving priority mode is selected, the heating control unit 712 continues operation of the compressor 22 at the condensation temperature CT determined from the graph of
***Description of Structure***
The heating control device 700 is a computer. The heating control device 700 includes a processor 710. The heating control device 700 includes, in addition to the processor 710, other pieces of hardware such as a main storage device 720, an auxiliary storage device 730, an input IF 740, an output IF 750, and a communication IF 760. The processor 710 is connected to the other pieces of hardware via a signal line 770 to control the other hardware.
The heating control device 700 includes, as functional elements, the estimating unit 711 and the heating control unit 712. The functions of the estimating unit 711 and the heating control unit 712 are implemented by a heating control program 701.
The processor 710 is a device which executes the heating control program 701. The heating control program 701 is a program which implements the functions of the estimating unit 711 and the heating control unit 712. The processor 710 is an IC (Integrated Circuit) which performs arithmetic process. Specific examples of the processor 710 are CPU (Centra Processing Unit), DSP (Digital Signal Processor), and GPU (Graphics Processing Unit).
The main storage device 720 is a storage device. Specific examples of the main storage device 720 are SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory). The main storage device 720 retains the arithmetic results of the processor 710.
The auxiliary storage device 730 is a storage device which stores data in a non-volatile manner. The auxiliary storage device 730 has the heating control program 701 stored therein. A specific example of the auxiliary storage device 730 is HDD (Hard Disk Drive). Also, the auxiliary storage device 730 may be a portable recording medium such as SD (registered trademark) (Secure Digital) memory card, NAND flash, flexible disc, optical disc, compact disc, Blu-ray (registered trademark) disc, or DVD (Digital Versatile Disk).
The input IF 740 is a port to which data is inputted from each device. To the input IF 740, the indoor humidity sensor 501, the heated outside air temperature sensor 502, the outside air humidity sensor 601, the outside air temperature sensor 602, and the condensation temperature sensor 26a are connected. The output IF 750 is a port from which data is outputted by the processor 710 to various devices. To the output IF 750, the compressor 22 of the second refrigerant system 21 is connected. The communication IF 760 is a communication port for the processor 710 to communicate with another device. To the communication IF 760, the temperature/humidity setting device 520 is connected. Also, the temperature/humidity setting device 520 is connected to the system control device 511.
The processor 710 loads the heating control program 701 from the auxiliary storage device 730 into the main storage device 720, and reads and executes the heating control program 701 from the main storage device 720. The heating control device 700 may include a plurality of processors which replace the processor 710. The plurality of these processors share execution of the heating control program 701. As with the processor 710, each processor is a device which executes the heating control program 701. Data, information, signal values, and variable values to be used, processed, or outputted by the heating control program 701 are stored in the main storage device 720, the auxiliary storage device 730, or a register or cache memory in the processor 710.
The heating control program 701 is a program which causes a computer to execute each process, each procedure, or each step when “unit” in each of the estimating unit 711 and the heating control unit 712 is read as “process”, “procedure”, or “step”.
Also, the heating control method is a method to be performed by the heating control device 700 as a computer executing the heating control program 701. The heating control program 701 may be provided as being stored in a computer-readable recording medium or may be provided as a program product.
***Description of Operation***
Step S11, S13, and step S14 represent operation of the estimating unit 711. Step S12 represents operation of the heating control unit 712. The estimating unit 711 estimates a latent heat load of air present in a ventilation target space as a ventilation target. The ventilation target space as a ventilation target is a space of the interior 500. Step S15 to step S20 represent operation of the heating control unit 712. The heating control unit 712 controls a temperature of outside air by a heater, the outside air being supplied to the ventilation target space, in accordance with the latent heat load estimated by the estimating unit 711. The heater is the heat exchanger 26. The heat exchanger 26 as a heater is a condenser of the refrigerating cycle device where the refrigerant circulates, the refrigerating cycle device including the compressor 22, the heat exchanger 26 which functions as the condenser, the expansion valve 25 as an expansion mechanism, and the heat exchanger 24 which functions as an evaporator. As control of the temperature of the outside air, the heating control unit 712 controls the condensation temperature of the refrigerant in the heat exchanger 26 as a condenser.
<Step S11>
After the start of operation of the air conditioning system 100, at step S11, the estimating unit 711 acquires, from the outside air temperature sensor 602, the outside air temperature detected by the outside air temperature sensor 602.
<Step S12>
At step S12, the heating control unit 712 determines the first condensation temperature CTmin of the refrigerant and the second condensation temperature CTmax higher than the first condensation temperature CTmin, based on the outside air condition indicating at least either value of a detected temperature of outside air and a detected absolute humidity, which is an absolute humidity detected for outside air. The heating control unit 712 determines a condensation temperature CTi in a range between the first condensation temperature CTmin and the second condensation temperature CTmax. The first condensation temperature is CTmin described below, and the second condensation temperature is CTmax described below.
A specific process is as follows. The heating control unit 712 determines one [CTmax, CTmin] from among a plurality of [CTmax, CTmin], based on the acquired outside air temperature. The heating control unit 712 has the plurality of [CTmax, CTmin]. Each [CTmax, CTmin] of the plurality of [CTmax, CTmin] is associated with an outside air temperature. For example, [CTmax(1), CTmin(1)] is associated with a range of outside air temperatures equal to or higher than 18° C. and lower than 20° C., and [CTmax(2), CTmin(2)] is associated with a range of outside air temperatures equal to or higher than 20° C. and lower than 22° C. Thus, the heating control unit 712 can determine one [CTmax, CTmin] from the acquired outside air temperature. Note that when a plurality of [CTmax, CTmin] are associated with an outside air humidity, [CTmax, CTmin] may be determined from the outside air humidity detected by the outside air humidity sensor 601.
[CTmax, CTmin] are stored in the auxiliary storage device 730.
As described above, the outside air condition includes a detected temperature of outside air, and the heating control unit 712 determines the first condensation temperature CTmin and the second condensation temperature CTmax at higher temperatures as the detected temperature of outside air is lower. Also, the outside air condition includes a detected humidity of outside air, and the heating control unit 712 determines the first condensation temperature CTmin and the second condensation temperature CTmax at higher temperatures as the detected humidity of outside air is lower.
<Step S13>
At step S13, the estimating unit 711 acquires the current absolute humidity Xi of the interior 500 from the indoor humidity sensor 501. Also, the estimating unit 711 acquires the target absolute humidity X0 of the interior 500 set by the temperature/humidity setting device 520.
<Step S14>
At step S14, the estimating unit 711 calculates the difference ΔX between the target absolute humidity X0 and the absolute humidity Xi of the interior 500. The estimating unit 711 calculates X0−Xi=ΔX.
The estimating unit 711 estimates the latent heat load ΔX based on X0 as the target humidity set by the temperature/humidity setting device 520 as a setting device which sets a target humidity in the ventilation target space and the detected humidity in the ventilation target space detected by the indoor humidity sensor 501.
Note that in place of the target absolute humidity X0, the estimating unit 711 may acquire a target relative humidity from the temperature/humidity setting device 520 and may acquire the temperature of the interior 500 from the temperature sensor which detects the temperature of the interior 500. The estimating unit 711 may calculate the target absolute humidity X0 from the target relative humidity and the temperature of the interior 500. Similarly, in place of the absolute humidity Xi, the estimating unit 711 may acquire a relative humidity of the interior 500 from the humidity sensor which detects the relative humidity of the interior 500 and may acquire the temperature of the interior 500 from the temperature sensor which detects the temperature of the interior 500. The estimating unit 711 may calculate the absolute humidity Xi of the interior 500 from the relative humidity of the interior 500 and the temperature of the interior 500.
<Step S15>
At step S15, the heating control unit 712 generates a graph of
<Step S16>
At step S16, the heating control unit 712 determines the condensation temperature CTi of the refrigerant from the value indicated by the latent heat load ΔX, and controls the operation frequency of the compressor 22 so that the condensation temperature of the refrigerant in the heat exchanger 26 as a condenser is closer to the determined condensation temperature CTi. Description is specifically made below. The heating control unit 712 controls the operation frequency of the compressor 22 so that the condensation temperature CT of the refrigerant in the heat exchanger 26 is the determined condensation temperature CTi. The heating control unit 712 acquires the condensation temperature of the refrigerant detected by the condensation temperature sensor 26a. With reference to the condensation temperature of the refrigerant detected by the condensation temperature sensor 26a, the heating control unit 712 controls the operation frequency of the compressor 22 so that the condensation temperature CT of the refrigerant is the determined condensation temperature CTi.
When the determined condensation temperature CTi is higher than the current condensation temperature of the refrigerant detected by the condensation temperature sensor 26a, the heating control unit 712 performs control of increasing the operation frequency of the compressor 22. When the determined condensation temperature CTi is lower than the current condensation temperature of the refrigerant detected by the condensation temperature sensor 26a, the heating control unit 712 performs control of decreasing the operation frequency of the compressor 22.
<Step S17>
At step S17, the heating control unit 712 acquires, from the heated outside air temperature sensor 502, the blowout temperature Tsa detected by the heated outside air temperature sensor 502.
<Step S18>
At step S18, the heating control unit 712 determines whether the mode is the blowout-temperature priority mode. The heating control unit 712 has already acquired information about whether the mode is the blowout-temperature priority mode from the temperature/humidity setting device 520. When the mode is not the blowout-temperature priority mode, the process returns to step S11. When the mode is the blowout-temperature priority mode, the process proceeds to step S19. The blowout-temperature priority mode is a mode in which the heating control unit 712 controls the blowout temperature Tsa so that the blowout temperature Tsa is equal to or larger than the threshold TH.
<Step S19>
At step S19, the heating control unit 712 determines whether the blowout temperature Tsa is smaller than the threshold TH. When the blowout temperature Tsa is not smaller than the threshold TH, the process returns to step S11. When the blowout temperature Tsa is smaller than the threshold TH, the process proceeds to step S20.
<Step S20>
At step S20, the heating control unit 712 controls the operation frequency of the compressor 22 so that the blowout temperature Tsa is equal to or larger than the threshold TH. Specific control is as follows.
The heating control unit 712 has the threshold TH. The threshold TH is stored in the auxiliary storage device 730. The heating control unit 712 performs control of increasing the operation frequency of the compressor 22 when the blowout temperature Tsa, which is the temperature of heated outside air detected by the heated outside air temperature sensor 502 which detects the temperature of heated outside air, is smaller than the threshold TH. Heated outside air is outside air supplied to the interior 500 as a ventilation target space, and is outside air heated by the heat exchanger 26 as a heater.
The heating control device 700 controls the condensation temperature of the refrigerant of the heat exchanger 26 in accordance with the latent heat load ΔX. When the latent heat load ΔX is low, the heating control device 700 decreases the condensation temperature CT of the refrigerant in the heat exchanger 26 to decrease the amount of heating outside air by the heat exchanger 26. Thus, efficiency of operation of the refrigerating cycle is enhanced, and energy can be saved. Also, when the latent heat load ΔX is high, the heating control device 700 increases the condensation temperature CT of the refrigerant in the heat exchanger 26 to increase the amount of heating outside air by the heat exchanger 26. Thus, shortage of the amount of humidification of outside air can be avoided.
Also, as illustrated at step S20 of
<Supplement to Hardware Structure>
While the functions of the estimating unit 711 and the heating control unit 712 are implemented by software in the heating control device 700 of
Each of the processor 710 and the electronic circuit 910 is also referred to as processing circuitry. In the heating control device 700, the functions of the estimating unit 711, the heating control unit 712, the main storage device 720, the auxiliary storage device 730, the input IF 740, the output IF 750, and the communication IF 760 may be implemented by processing circuitry.
This application is a U.S. National Stage Application of International Application No. PCT/JP2020/018993, filed on May 12, 2020, the contents of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2020/018993 | 5/12/2020 | WO |