JP2606546B2 - Control method at the start of heating of air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method at the start of heating of an air conditioner. In particular, the present invention relates to a control method at the start of heating in an air conditioner that heats a room using heat of a heat medium such as hot water.

[0002]

2. Description of the Related Art As a heating function in an air conditioner,
An air conditioner has generally been proposed in which heat generated by an electric heater is generally used, but recently, hot water is circulated as a heat medium to heat the room using the heat. Such an air conditioner is disclosed in JP-A-2-1033.
There is one disclosed in Japanese Patent Publication No. 30.

[0003] In the air conditioner in which the interior of the room is heated by using the hot water as described above, during the heating operation, hot water of a constant temperature is circulated through a heating medium pipe through a heating radiator provided in the indoor unit. The room temperature is controlled so as to reach the set temperature by adjusting the flow rate of the hot water by the flow control valve provided in the heat medium pipe.

When the heating operation is started, as shown in FIG. 9 (b), the flow control valve is once opened from the fully closed position to the fully opened position, then closed again to the intermediate position, and then the normal control operation (fuzzy control operation) is performed. ). This is for the following reasons. The flow rate value with respect to the valve opening degree of the flow control valve shows hysteresis as shown in FIG. 10, when the flow control valve is opened from the fully closed position to the intermediate position, and when the flow control valve is once opened to the fully open position and then returned to the intermediate position. And the flow rates are slightly different. When the two characteristics are compared, the flow characteristic when returning from the fully opened position to the intermediate position is more preferable in terms of design. For this reason, as described above, the flow rate value at the time of returning from the fully open state to the intermediate position is selected to unify the characteristics.

[0005]

However, if the normal control operation is started immediately after returning the flow control valve from the fully open position to the intermediate position as described above, the temperature difference between the room temperature and the set temperature is large. Since the flow control valve is excessively opened so as to rapidly raise the temperature to the set temperature, the room temperature is rapidly raised. On the other hand, even when the room temperature approaches the set temperature, it takes time to close the flow control valve and reduce the flow rate, and to lower the room temperature, it is necessary to reduce the flow rate of hot water and wait for the room temperature to drop naturally. Therefore, there is a problem that the room temperature control in the initial stage is almost delayed, and as shown in FIG. 9A, the room temperature greatly overshoots and the room temperature at the start of heating becomes too high.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and has as its object to provide an air conditioner that performs heating using the heat of hot water in an initial condition at the start of heating. Is to improve.

[0007]

According to the control method of the present invention at the time of starting heating of an air conditioner, heating is performed by a heating medium flowing through a heating radiator, and the flow rate of the heating medium is adjusted by a flow control valve. In the air conditioner whose capacity is controlled, a control method at the time of a heating operation start in which the flow control valve shifts from an initial operation state in which the flow control valve reaches an intermediate position between a fully closed state and a fully opened state through a full open state to a normal operation state. When the room temperature is lower than the set temperature , when the room temperature rises above a certain temperature lower than the set temperature, the flow control valve is shifted from the initial operation state to the normal control state.

In the above control method, when a predetermined time has elapsed from the start of the heating operation, the flow control valve is shifted to the normal control state even if the room temperature has not risen above the predetermined temperature. You may.

Further, in the above control method, when the room temperature is higher than the set temperature , and when the room temperature falls below a certain temperature higher than the set temperature, the flow control valve is brought into the initial operation state and the normal control state. You may make it transfer.

[0010]

According to the present invention, at the start of the heating operation,
When the room temperature is lower than the set temperature, the flow control valve is kept in the initial operation state, and when the room temperature becomes higher than a predetermined temperature which is set below the set temperature, the flow control valve is shifted to the normal control state. As a result, the control does not become excessive when the state is shifted to the normal control state, and the room temperature control does not become too late.

Further, if a certain period of time has elapsed from the start of the heating operation, the flow control valve is shifted to the normal control state, so that the heating capacity of the air conditioner is insufficient and the flow control valve is kept at the intermediate position. If the room temperature does not rise easily, the state shifts to the normal control state after a certain period of time, and the room can be quickly heated.

Further, when the room temperature is higher than the set temperature, the room temperature drops below a certain temperature higher than the set temperature.
In this case, the flow control valve is controlled in the initial operation state, and thereafter, the flow control valve is shifted to the normal control state. The heating operation can be started at the time when the temperature is lowered.

[0013]

【Example】

(Cooling Function) FIG. 1 is a schematic configuration diagram showing an air conditioner according to one embodiment of the present invention. The air conditioner 1 mainly includes an indoor unit 2, an outdoor unit 3, and a heating heat source unit 4. The refrigerant circulation circuit 5 connects the compressor 6, the condenser 7, and the capillary tube 8 provided inside the outdoor unit 3 and the evaporative heat exchanger 9 provided inside the indoor unit 2 via a refrigerant pipe 10. Connected and configured. A radiating fan 11 for radiating heat of the condenser 7 to the outside is provided inside the outdoor unit 3, and condensed below the evaporative heat exchanger 9 inside the indoor unit 2. Drain pan 1 for receiving and discharging water droplets adhering to evaporative heat exchanger 9
2 are provided.

Thus, by operating the refrigerant circulation circuit 5, it is possible to perform indoor cooling by the same operation as a general cooling device. That is, during the cooling operation, when the compressor 6 is operated to condense in the condenser 7 and the condensed refrigerant is repeated in the evaporative heat exchanger 9 to repeat the thermodynamic cycle, the refrigerant evaporates in the evaporative heat exchanger 9. It takes away the surrounding heat as heat of vaporization. Therefore, the air that has flowed in from the air intake 13 of the indoor unit 2 is cooled by the evaporative heat exchanger 9, and the cooled air is sent out from the outlet 15 of the indoor unit 2 into the room by the blower fan 14, thereby cooling the room. Is performed.

(Heating Function) The heating medium circulation circuit 21
A heating medium heater 22 and a pump 23 disposed inside the heating heat source unit 4; and a heating radiator 2 disposed inside the indoor unit 2
4 is connected through a heat medium pipe 26,
The heat medium pipe 26 is provided with a flow control valve 25 and a temperature sensor 27. A heat medium such as hot water exists in the heat medium circulation circuit 21, and when the pump 23 is operated, the heat medium is forcibly circulated in the heat medium circulation circuit 21. The heat medium heater 22 includes, for example, a heat exchanger 22a and a gas burner 22b, and the amount of heat of the heat medium heater 22 is controlled by a heat medium temperature control unit 29 so that the temperature of the heat medium is constant. That is, the temperature of the heat medium flowing out of the heat medium heater 22 is detected by the temperature sensor 27 provided on the outlet side of the heat exchanger 22a, and the heat medium temperature control unit 29 detects the heat medium temperature detected by the temperature sensor 27. Based on the medium temperature, for example, the proportional control valve 28 of the gas burner 22b is feedback-controlled so that the temperature of the heat medium flowing out of the heat medium heater 22 becomes constant. Thus, the heat medium of a constant temperature sent to the heating radiator 24 through the heating medium pipe 26 is
The air that has flowed in through the air intake 13 is heated by exchanging heat with the heat medium by the heating radiator 24, and the warmed air is blown by the blower fan 14 into the outlet 1 of the indoor unit 2.
5 to the room, and the room is heated.

On the other hand, the room temperature Tr, that is, the amount of heat radiated from the heating radiator 24 is controlled by the flow control valve 25 by the heat medium circulating circuit 2.
It is adjusted by controlling the flow rate of the heat medium circulating in the flow path 1. The room temperature Tr is detected by a room temperature sensor 30 provided in the indoor unit 2, and a desired value of the room temperature Tr is set by a setting device (for example, a temperature setting switch provided in a control panel, a remote controller, or the like) 31. I can do it. When the set value of the room temperature (set temperature Ts) is input by the setter 31,
The room temperature controller 32 determines the room temperature Tr based on the deviation between the room temperature Tr detected by the room temperature sensor 30 and the set temperature Ts.
Is controlled by the flow rate control valve 25 so that is equal to the set temperature Ts.

(Normal Control Operation) The heating operation of the air conditioner 1 is divided into an initial operation at the start of heating and a subsequent normal control operation. The room temperature control during the normal control operation (normal control state) is performed by the room temperature control unit 32 by the flow control valve 2.
5 is fuzzy controlled. First, the normal control operation will be described. The room temperature controller 32 includes the room temperature sensor 30
Is obtained at every predetermined sampling time t, and a difference F (t) = Ts−Tr ^now between the set temperature Ts at the sampling time t and the current room temperature data Tr ^now is obtained. At the same time, the value per unit time of the difference between the current room temperature data Tr ^now and the immediately preceding room temperature data Tr ^old , that is, the temperature change rate D _T = (Tr ^now −Tr ^old ) / Δt. Here, Δt is an interval of the sampling time t.

Next, temperature difference fuzzy data is obtained with reference to the membership function of FIG. In FIG. 2, the horizontal axis represents the temperature difference F (t) defined by the equation, the vertical axis represents the grade of the fuzzy variable, and NB is a fuzzy variable indicating that "the room temperature Tr is higher than the set temperature Ts". Is a fuzzy variable indicating that the room temperature Tr is slightly higher than the set temperature Ts, ZO is a fuzzy variable indicating that it is "just right", PM is a fuzzy variable indicating that the room temperature Tr is slightly lower than the set temperature Ts, and PB Is a fuzzy variable indicating that “the room temperature Tr is lower than the set temperature Ts”. Therefore, referring to each membership function in FIG. 2, each fuzzy variable NB, NM, ZO,
The grades of PM and PB can be obtained. Further, temperature change rate fuzzy data is obtained with reference to the membership function of FIG. In FIG. 3, the horizontal axis represents the temperature change rate _DT defined by the equation, the vertical axis represents the grade of the fuzzy variable, and N is a fuzzy variable indicating that "the room temperature Tr is changing negatively". Is a fuzzy variable indicating "no change in room temperature Tr", and P is "a room temperature Tr is positively changed".
Is a fuzzy variable indicating that Therefore, referring to each membership function in FIG. 3, the grade of each fuzzy variable N, Z or P at the temperature change rate _DT can be obtained.

For example, at a certain sampling time t, the set temperature Ts = 26 ° C., and the current room temperature data Tr ^now =
21.8 ° C, previous room temperature data Tr ^old = 20.75 ° C
From the equation, F (t) = + 4.2 ° C. Therefore, referring to the membership function of FIG. 2, the grade values of each fuzzy variable are NB = 0, NM = 0, ZO = 0, PM = 0, P
B = 1.0. On the other hand, from the equation, the temperature change rate D _T = + 1.05 ° C.
/ Sec (sampling time interval Δt = 1 second)
Therefore, referring to the membership function of FIG.
The grade value of each fuzzy variable is N = 0, Z = 0.5, P = 0.5.

Next, the room temperature control unit 32 operates as shown in FIG.
With reference to the five control rules, the output membership value is obtained from the temperature difference fuzzy data and the temperature change rate fuzzy data calculated as described above.

[0021]

[Table 1]

The output membership function for opening and closing the flow control valve 25 is shown in FIG. 4, where NBv is a fuzzy variable indicating "close the flow control valve 25",
NMv is a fuzzy variable indicating that the flow control valve 25 is slightly closed, ZOv is a fuzzy variable indicating that the opening degree of the flow control valve 25 is kept as it is, and PMv is a fuzzy variable indicating that the flow control valve 25 is slightly opened. Fuzzy variable, PB
“v” is a fuzzy variable indicating “open the flow control valve 25”, and is assigned a control amount G of the flow control valve 25 as shown in FIG. Control rules in Table 1 (fuzzy rules)
For example, rule R1 states that the fuzzy variable of the temperature difference F (t) is NB (the room temperature Tr is higher than the set temperature Ts) and the fuzzy variable of the temperature change rate D _T is N ( If the change is negative, the fuzzy variable of the output membership function is set to NMv (close the flow control valve 25 slightly). "The temperature difference fuzzy data and the temperature change rate fuzzy data are obtained. Are satisfied by the min operation. That is, the smaller of the grade of the fuzzy variable indicating the temperature difference and the grade of the fuzzy variable indicating the temperature change rate is taken as the grade of the output membership value. For example, when the rule of R1 is specifically described using the above numerical values, the grade value of the fuzzy variable NB indicating the temperature difference F (t) is NB = 0, and the grade value of the fuzzy variable N indicating the temperature change rate D _T is Since N = 0,
The grade of the output membership value is NMv = 0.
The fuzzy variable of the temperature difference F (t) is PB (room temperature T
r is lower than the set temperature Ts) and the temperature change rate D _T
If the fuzzy variable is P (positively changing), the fuzzy variable of the output membership function is set to PMv (the flow control valve 25 is slightly opened). ", The grade value of the fuzzy variable PB is PB = 1.
Since 0 and the grade value of the fuzzy variable P are P = 0.5, the grade of the output membership value is PMv = 0.5. By performing the min operation on the rules R1 to R15 in this manner, the following 15 output membership values are obtained. R1: NMv = 0 R2: ZOv = 0 R3: PMv = 0 R4: PBv = 0 R5: PBv = 0 R6: NBv = 0 R7: NMv = 0 R8: ZOv = 0 R9: PMv = 0 R10: PBv = 0 .5 R11: NBv = 0 R12: NBv = 0 R13: NMv = 0 R14: NMv = 0 R15: PMv = 0.5 Seeking). For example, the above 15 output membership values are NBv, NM
By performing a max operation for each of v, ZOv, PMv, and PBv, the following output membership composite value is obtained: NBvm = 0 NMvm = 0 ZOvm = 0 PMvm = 0.5 PBvm = 0.5 The composite value obtained by the mini-max operation is subjected to a single-point operation (weighted average). That is,
The control amount G is calculated according to the following equation.

[0023]

(Equation 1)

The weighting coefficients in the one-point arithmetic expression are, for example, a = -12, b = -6, c = 0, d = + 6,
It is predetermined such that e = + 12. Therefore, using the above values as output membership values,
The control amount G is G = + 9.

[0025] Thus, determining the target address Gs by adding the control amount G = + 9 of the flow control valve 25 determined by the fuzzy inference to the current address G _0. For example, if the current address G ₀ = 10, the target address is Gs = G ₀ + G = 1
Since 0 + 9 = 19, assuming that the relationship between the address of the flow control valve 25 and the number of steps is given in Table 2 below, the flow control valve 25 is driven in the opening direction by 2202-1870 = 350 steps. become.

[0026]

[Table 2]

According to this method, the address is calculated by fuzzy inference, and a table of the address-step number may be prepared according to the characteristics of the flow control valve 25. Even if the characteristic is not linear (non-linear), there is an advantage that it is not necessary to change the control calculation formula in the valve opening range.

(Initial Operation) Next, an initial operation at the start of the heating operation will be described. Initial operation is performed at room temperature Tr and set temperature T.
It depends on the relationship with s. That is, the initial operation differs depending on three conditions: Tr <Ts−2 ° C. Ts−2 ° C. ≦ Tr ≦ Ts + 3 ° C. Ts + 3 ° C. <Tr The values of 2 ° C. and 3 ° C. used here are merely examples, and are not limited to these numbers, and can be freely determined as appropriate.

[Case of Ts−2 ° C. ≦ Tr ≦ Ts + 3 ° C.] First, FIG. 5 shows an initial operation when the room temperature Tr is close to the set temperature Ts and the above conditions are satisfied. When the heating switch is turned on, the flow control valve 2 which was in the fully closed position until then is turned on.
5 is opened to the fully open position, and when it is detected that it has been opened to the fully open position, it is returned to the intermediate position. This is because, as described in the conventional example, a flow rate characteristic is selected and a variation in the flow rate characteristic is eliminated. The intermediate position is not limited to the center between the fully closed position and the fully open position, but may be an appropriate position between the fully closed position and the fully open position. Upon detecting that the opening of the flow control valve 25 has returned to the intermediate position, the room temperature control unit 32 immediately shifts to the normal control operation.

When the temperature difference between the room temperature Tr and the set temperature Ts is small, there is a small possibility that the room temperature Tr will overshoot at the start of heating. Therefore, under such conditions, a control method similar to the conventional method is employed. It is.

FIG. 6 shows the initial operation when the room temperature Tr is lower than the set temperature Ts by a certain temperature (2 ° C.) or more and the above conditions are satisfied.
When the heating switch is turned on, the flow control valve 25 that has been in the fully closed position is opened to the fully open position. When it is detected that the flow control valve 25 has been opened to the fully open position, the flow control valve 25 is returned to the intermediate position and held at the intermediate position. . When the flow control valve 25 is fixed at the intermediate position in this way, the room temperature Tr gradually rises during that time, so that the room temperature Tr detected by the room temperature sensor 30 is equal to or higher than Ts−2 ° C. (Ts−2 ° C. ≦ Tr), the room temperature controller 32 immediately shifts to the normal control operation.

When the temperature difference between the room temperature Tr and the set temperature Ts is large as described above, the flow control valve 25 is returned to the intermediate position, and immediately after the flow control valve 25 is returned to the intermediate position, the normal control operation is not performed.
By keeping 5 at the intermediate position, the room temperature Tr can be prevented from rising rapidly, and the room temperature Tr can be gradually raised to near the set temperature Ts. As a result, the room temperature Tr
The normal control operation is performed after the temperature difference between the set temperature Ts and the set temperature Ts is reduced, so that overshooting of the room temperature Tr can be prevented.

However, also in this case, it may be considered that the amount of heat is insufficient to raise the room temperature Tr at the flow rate of the heat medium at the intermediate position. Therefore, as shown in FIG. 7, if the room temperature Tr does not become Ts−2 ° C. or more after a certain time ts (for example, 4 minutes) has elapsed from the start of operation,
Is forcibly shifted to the normal control operation when the predetermined time ts has elapsed even if the temperature is lower than Ts-2 ° C. When the operation shifts to the normal control operation, the flow rate control valve 25 is opened and the flow rate of the heat medium increases, so that the room temperature Tr immediately rises to the set temperature Ts.

[Ts + 3 ° C. <Tr] Next, FIG. 8 shows an initial operation when the room temperature Tr is higher than the set temperature Ts by a certain temperature (3 ° C.) or more and the above conditions are satisfied.
The room temperature Tr when the heating switch is turned on is the set temperature T
If the temperature is much higher than s, the heating operation does not need to be performed until the room temperature Tr drops to near the set temperature Ts. Therefore, the room temperature control unit 32 monitors the room temperature Tr and determines that the room temperature Tr is Ts + 3 ° C. or less (Tr ≦ Ts + 3 ° C.). When this happens, the initial operation is started, the flow control valve 25 is opened from the fully closed position to the fully open position, then returned to the intermediate position, and the process immediately shifts to the normal control operation.
Also in this case, the normal operation is performed in a state where the room temperature Tr is close to the set temperature Ts, so that an undershoot or an overshoot of the room temperature Tr is avoided.

In the above-mentioned air conditioner, the refrigerant circulation circuit and the heat medium circulation circuit are operated simultaneously,
Dry operation (dehumidification operation) is also possible.

[0036]

According to the present invention, at the start of the heating operation, the flow control valve is maintained in the initial operation state without shifting to the normal control state until the room temperature becomes higher than a predetermined temperature equal to or lower than the set temperature. Therefore, when the normal control state is entered, the control does not become excessive, and the room temperature control does not become too late. Therefore, it is possible to prevent the room temperature from overshooting at the start of the heating operation and prevent the room temperature at the start of the heating from becoming too high, thereby improving the initial characteristics during the heating operation.

If a certain period of time has elapsed since the start of the heating operation, the flow control valve is shifted to the normal control state, so that the heating capacity of the air conditioner is insufficient and the flow control valve is kept at the intermediate position. If the room temperature does not rise easily, the state shifts to the normal control state after a certain period of time, and the room can be quickly heated.

Further, when the room temperature is higher than the set temperature, after the room temperature falls below a certain temperature higher than the set temperature, the flow control valve is brought into an initial operation state, and thereafter the flow control valve is put into a normal control state. Therefore, when the room temperature is higher than the set temperature, the heating operation can be started when the room temperature drops to near the set temperature. Therefore, it is possible to prevent the room temperature from abnormally rising immediately after the heating switch is turned on, and prevent unnecessary heating operation from being performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an air conditioner according to one embodiment of the present invention.

FIG. 2 is a diagram showing a membership function expressing a temperature difference between a set temperature and a room temperature.

FIG. 3 is a diagram illustrating a membership function expressing a temperature change rate at room temperature.

FIG. 4 is a diagram showing an output membership function.

FIG. 5 is a diagram showing a control operation during a heating operation,
(A) is a figure which shows the change of room temperature, (b) is a figure which shows the control state of the flow control valve.

6A and 6B are diagrams showing a control operation during a heating operation under another condition, wherein FIG. 6A is a diagram showing a change in room temperature, and FIG. 6B is a diagram showing a control state of a flow control valve.

FIG. 7 is a diagram showing another control operation at the time of the heating operation under the same conditions as the above, wherein (a) is a diagram showing a change in room temperature,
(B) is a figure which shows the control state of the flow control valve.

FIG. 8 is a diagram showing a control operation at the time of heating operation under still another condition, wherein (a) is a diagram showing a change in room temperature;
(B) is a figure which shows the control state of the flow control valve.

9A and 9B are diagrams showing a control operation during a heating operation in a conventional example, in which FIG. 9A shows a change in room temperature, and FIG. 9B shows a control state of a flow control valve.

FIG. 10 is a diagram showing a relationship between an opening degree of a flow control valve and a flow rate.

[Explanation of symbols]

 21 Heat medium circulation circuit 22 Heat medium heater 24 Heating radiator 25 Flow control valve 30 Room temperature sensor 31 Setting unit 32 Room temperature control unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirofumi Tanaka 32nd Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Pref. 72) Inventor Yukari Hamakachi 32, Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Pref.

Claims (3)

(57) [Claims] 1. An air conditioner in which heating is performed by a heat medium flowing through a heating radiator and a heating capacity is controlled by adjusting a flow rate of the heat medium by a flow control valve, wherein the flow control valve is fully opened. This is a control method at the start of heating operation that shifts from the initial operating state to the intermediate position between fully closed and fully open to the normal operating state, and when the room temperature is lower than the set temperature, a constant temperature smaller than the set temperature A control method at the time of starting heating of the air conditioner, characterized in that when the room temperature rises , the flow control valve is shifted from the initial operation state to the normal control state. 2. When a certain period of time has elapsed from the start of the heating operation, even if the room temperature has not risen above the certain temperature,
2. The control method according to claim 1, wherein the flow control valve is shifted to a normal control state. 3. When the room temperature is higher than the set temperature , when the room temperature falls below a certain temperature higher than the set temperature,
The control method at the time of starting heating of the air conditioner according to claim 1 or 2, wherein the flow control valve is shifted to an initial operation state and a normal control state.