JP3174108B2 - Air conditioning - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling / heating apparatus separated into a heat source side refrigerant cycle and a user side refrigerant cycle.

[0002]

2. Description of the Related Art A conventional cooling / heating apparatus separated into a heat source side refrigerant cycle and a user side refrigerant cycle is disclosed in
No. 2,272,040.

Hereinafter, a conventional air conditioner of this type will be described with reference to the drawings. FIG. 4 shows a block diagram of a conventional air conditioner. In FIG.
1 is a compressor, 2 is a four-way valve, 3 is a heat source side heat exchanger, 4 is a decompression device, and 5 is a first auxiliary heat exchanger which is connected in a ring shape to the heat source side. A refrigerant cycle 6 is formed.

[0004] A second auxiliary heat exchanger 7 is formed integrally with the first auxiliary heat exchanger 5 so as to exchange heat. A user side heat exchanger 8 is housed in the indoor unit 9.
Reference numeral 10 denotes a refrigerant pump for sending a refrigerant.

[0005] Reference numeral 11 denotes a first solenoid valve installed in series between the outlet of the refrigerant pump 10 and the user-side heat exchanger 8,
12 is a second solenoid valve installed in series between the inlet of the refrigerant pump 10 and the user side heat exchanger 8, 13 is serially connected between the inlet of the refrigerant pump 10 and the second auxiliary heat exchanger 7 The third solenoid valve 14 installed in the refrigerant pump 10
And a fourth solenoid valve installed in series between the outlet of the second auxiliary heat exchanger 7 and the second auxiliary heat exchanger 7, the user-side heat exchanger 8, the refrigerant pump 10, A first solenoid valve 11, the second solenoid valve 12, the third solenoid valve 1
3. The user-side refrigerant cycle 15 is formed by connecting the fourth solenoid valve 14 in an annular manner.

[0006] The operation of the cooling / heating device configured as described above in the case of the cooling operation will be described below.

First, consider the case of the cooling mode. In the heat source side refrigerant cycle 6, the high temperature and high pressure gas from the compressor 1 passes through the four-way valve 2, radiates heat in the heat source side heat exchanger 3, condenses and liquefies, is decompressed by the decompression device 4, and evaporates in the first auxiliary heat exchanger 5. Through the four-way valve 2 to the compressor 1.

At this time, the second refrigerant cycle 15 of the user side
The auxiliary heat exchanger 7 and the first auxiliary heat exchanger 5 exchange heat, and the gas refrigerant in the user-side refrigerant cycle 15 is cooled and liquefied. The liquefied refrigerant passes through the third electromagnetic valve 13, the refrigerant pump 10, and the first electromagnetic valve 11, is sent to the user-side heat exchanger 8, cools, absorbs heat, evaporates and gasifies, and the user-side refrigerant cycle 15 In the second auxiliary heat exchanger 7.

Next, consider the case of the heating mode. In the heat source side refrigerant cycle 6, the high temperature and high pressure gas from the compressor 1 passes through the four-way valve 2, radiates heat in the first auxiliary heat exchanger 5, condenses and liquefies, is decompressed by the decompression device 4, and evaporates in the heat source side heat exchanger 3. Through the four-way valve 2 to the compressor 1.

At this time, the second refrigerant cycle 15 of the user side
The auxiliary heat exchanger 7 and the first auxiliary heat exchanger 5 exchange heat, and the gas refrigerant in the user-side refrigerant cycle 15 is heated and gasified. The gasified refrigerant is sent to the user-side heat exchanger 8, heated, radiated and condensed, liquefied, passed through the second electromagnetic valve 12, the refrigerant pump 10, and the fourth electromagnetic valve 14, and then cooled to the user-side refrigerant cycle. It will circulate to the 15 second auxiliary heat exchanger 7.

[0011]

However, in the above-mentioned conventional structure, when a large amount of liquid refrigerant flows into the refrigerant pump 10 and becomes full, the refrigerant pump 10 causes abnormal pressure pulsation due to liquid compression, and the pump life is shortened. Not only that, the pipe has a disadvantage that the vibration of the pipe is increased and the pipe is damaged at worst.

The present invention has been made in view of the above problems, and has as its object to suppress the flow of liquid refrigerant into a refrigerant pump.

[0013]

Means for Solving the Problems In order to solve the above problems, a cooling and heating apparatus according to the present invention comprises a compressor, a heat source side heat exchanger,
It has a heat-source-side refrigerant cycle in which the pressure reducing device and the first auxiliary heat exchanger are connected in a ring shape.

In addition, a second auxiliary heat exchanger formed integrally with the first auxiliary heat exchanger for heat exchange, a user-side heat exchanger,
A refrigerant pump for sending refrigerant, a first solenoid valve installed in series between the refrigerant pump outlet and the user-side heat exchanger,
A second solenoid valve installed in series between the refrigerant pump inlet and the user-side heat exchanger, a third solenoid valve installed in series between the refrigerant pump inlet and the second auxiliary heat exchanger, There is a user-side refrigerant cycle in which a fourth solenoid valve installed in series between the refrigerant pump outlet and the second auxiliary heat exchanger is connected in a ring shape.

A refrigerant pump driving current detector provided for the refrigerant pump for detecting a driving current of the refrigerant pump; and a detection value of the refrigerant pump driving current detector for inputting the first to fourth electromagnetic signals. A control device for controlling the valve is provided.

The control device further comprises a cooling / heating mode detecting means for detecting cooling or heating, and a current difference calculating means for calculating a current difference by subtracting a preset value from a value detected by the refrigerant pump driving current detector. And a differentiating means for calculating and outputting a change rate of the output of the current difference calculating means in a very short time; and outputting the first to fourth information with respect to information on the output of the current difference calculating means and the output of the differentiating means. A memory device is provided for storing a control rule based on an empirical rule for obtaining the operation amount of the solenoid valve.

Further, a fuzzy logic operation is performed based on the output information of the current difference calculating means, the output information of the differentiating means, and the control rules taken out of the memory device to determine whether the refrigerant pump is performing liquid compression. Judge the first
Fuzzy inference means for calculating the operation amount of the fourth solenoid valve from the control unit, and electromagnetic valve opening / closing control means for determining and controlling the operation amount of the first to fourth solenoid valves based on the inference result performed by the fuzzy inference means And

[0018]

According to the present invention, the control device operates the first solenoid valve and the third solenoid valve during the cooling operation and the second solenoid valve during the heating operation.
By controlling the electromagnetic valve and the fourth electromagnetic valve, the liquid refrigerant flowing into the refrigerant pump can be suppressed, so that abnormal pressure pulsation of the refrigerant pump is eliminated.

Since there is a correlation between the current for driving the refrigerant pump and the abnormal pressure pulsation of the refrigerant pump, the presence or absence of the abnormal pressure pulsation can be determined by detecting the driving current of the refrigerant pump and used as a determination for the solenoid valve control. it can.

Further, a value of current difference calculating means for calculating a current difference by subtracting a preset value from the detection value of the refrigerant pump driving current detector for the opening / closing degree of the solenoid valve and a differentiating means for calculating a rate of change thereof. Is fuzzy inferred by a control rule based on an empirical rule extracted from the memory device, and based on the result, the opening / closing degree of the first to fourth solenoid valves is determined and controlled by the solenoid valve opening / closing control means. The first to fourth solenoid valves can be controlled with an optimum opening / closing degree.

Further, since the refrigerant can always be optimally supplied to the user side cycle, the room temperature can be smoothly controlled without being disturbed, and comfortable air cleaning can be realized.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a cooling and heating apparatus according to an embodiment of the present invention.

FIG. 1 is a block diagram showing a cooling and heating apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 16 denotes a refrigerant pump driving current detector provided for the refrigerant pump 10 and detects a driving current of the refrigerant pump 10;
Is a control device for controlling the electromagnetic valves 11, 12, 13, and 14.

Numeral 18 denotes cooling / heating mode detecting means for detecting cooling or heating, and 19 subtracts a preset value (the driving current of the refrigerant pump 10 at the start of liquid compression) from the value detected by the refrigerant pump driving current detector 16. The current difference calculating means 20 for calculating the current difference is a differentiating means for differentiating the calculated value obtained from the current difference calculating means 19 to calculate the rate of change ΔC of the current of the refrigerant pump 10.

Reference numeral 21 denotes a microprocessor which comprises a memory device 22 for storing control rules and fuzzy inference means 23.

When the cooling / heating mode detecting means 18 detects cooling and the value inferred by the fuzzy inference means 23 is 1, it is assumed that the refrigerant pump 10 is performing liquid compression and the first solenoid valve 11 is opened. When the third solenoid valve 13 is repeatedly opened and closed, and the value inferred by the fuzzy inference means 23 is not 1, it is determined that the refrigerant pump 10 has not been liquid-compressed.
And the third solenoid valves 11 and 13 are opened. At this time, the second and fourth solenoid valves 12, 14 are driven to close.

When the heating / cooling mode detecting means 18 detects heating and the value inferred by the fuzzy inference means 23 is 1, the refrigerant pump 10 is assumed to be in liquid compression and the fourth solenoid valve 14 is opened. When the value inferred by the fuzzy inference means 23 is not 1 and the second solenoid valve 12 is repeatedly opened and closed, it is determined that the refrigerant pump 10 has not been liquid-compressed.
And the second solenoid valves 14 and 12 are opened. At this time, the first and third electromagnetic valves 11 and 13 are electromagnetic valve opening / closing driving means for driving to close, and these 18 to 24 are configured in the control device 17.

The operation of the cooling and heating apparatus of the present embodiment configured as described above will be described with reference to the drawings.

FIG. 2 shows a flowchart of this embodiment.
In FIG. 2, in STEP 1, the cooling / heating mode detecting means 18
Then, in STEP2, the value calculated by the current difference calculating means 19 and the value calculated by the differentiating means 20, that is, the change rate ΔC of the current difference, are calculated from (Equation 1) in STEP2. I do.

[0030]

(Equation 1)

Here, let us consider a case where the operation mode is cooling and the refrigerant pump 10 is not liquid-compressed. STEP3
Then, cooling is determined based on the data detected by the cooling / heating mode detecting means 18.

The current difference C and the current change rate ΔC calculated as described above are input to the fuzzy inference means 23. The memory device 22 stores control rules required for fuzzy inference executed by the fuzzy inference means 23. Fuzzy inference is performed based on the following control rules.

The control rules adopted in the present invention are the following nine rules. That is, Rule R1: If the current difference is small and the current change rate is small, the solenoid valve is opened. Rule R2: If the current difference is small and the current change rate is small, the solenoid valve is closed. Rule R3: If the current difference is large and the current change rate is small, the solenoid valve is opened.

Rule R9: If the current difference is large and the current change rate is large, the solenoid valve is opened. It is.

The language rules are control rules for determining the degree of opening and closing of the first to fourth solenoid valves, which are obtained by the inventor from empirical rules obtained from a number of experimental data. As shown in Table 1).

[0036]

[Table 1]

Table 1 shows the first to fourth data used in the present invention.
3 shows the relationship of the control rules for determining the degree of opening and closing of the solenoid valve. Table 1 is arranged in three stages (S = small, Z = zero or negative, B = large) in the horizontal direction according to the magnitude of the current change rate ΔC, and in the vertical direction according to the magnitude of the current difference C. Similarly, it is arranged in three stages (L = small, M = medium, H = large),
At the position where each of the divided current change rate ΔC and the current difference C intersects, a value that determines the optimal opening / closing degree of the first to fourth solenoid valves with respect to the current change rate ΔC and the intensity of the current difference C is provided. Is stored. Here, 1 is a value that assumes that the refrigerant pump 10 is liquid-compressed, drives the first solenoid valve 11 to open, and repeatedly drives the third solenoid valve to open and close.
0 is a value that assumes that the refrigerant pump 10 is not liquid-compressed and drives the first solenoid valve 11 and the third solenoid valve 13 to open.

The language rules are stored in the memory device 22 of FIG. 1, and are stored according to the following rules. The number of control rules used here is nine. Rule R1: IF Cis Land and ΔCis
S THEN F = 0 Rule R2: IF Cis Mand ΔCis
S THEN F = 1 Rule R3: IF Cis H and ΔCis
S THEN F = 1 ・ ・ ・ Rule R9: IF Cis H and ΔCis
B THEN F = 1 In more detail, the fuzzy inference means 23 takes out the control rules stored in advance in the memory device 22 and calculates the opening / closing degrees of the first to fourth solenoid valves by fuzzy inference.

Since the control rules R1 to R9 determine the opening and closing degrees of the first to fourth solenoid valves in a stepwise manner with respect to the current difference C and the current change rate ΔC, when fine control is performed, It is necessary to calculate the degree to which the antecedent part (IF part) of the control rule is satisfied and to estimate the opening / closing degrees of the first to fourth solenoid valves according to the degree. Therefore, in the present invention, a membership function of a fuzzy variable is used to calculate the degree.

FIG. 3A shows membership functions μL (C) and μM of the fuzzy variables L, M and H with respect to the current difference C.
FIG. 3B shows the membership functions μS (ΔC), μZ (ΔC), μB (Δ) of the fuzzy variables S, Z, and B with respect to the current change rate ΔC.
C).

The fuzzy inference executed by the fuzzy inference means 21 is based on the control rules R1 to R9 and FIG.
A fuzzy logic operation is performed using the membership function of (b) to calculate an operation amount. As the inference form, the max-min method was used for the synthesis method, and the height method was used for the single point method.
Hereinafter, the inference procedure will be described with reference to the flowchart of the present invention in FIG.

In STEP 4, the fuzzy inference means 23 calculates a membership value at the current difference C and the current change rate ΔC by using a membership function of a fuzzy variable with respect to the current difference C and the current change rate ΔC. STE
In P5, the degree of the obtained membership value in the antecedent part of each of the nine rules is calculated by a synthesis method.
(In FIG. 2, the fuzzy variable for the current is indicated by A, and the fuzzy variable for the current change rate is indicated by B.) The degree is shown in (Equation 2) to (Equation 4) below.

[0043]

(Equation 2)

[0044]

(Equation 3)

[0045]

(Equation 4)

In the equation (2), the current difference C is as shown in FIG.
The proposition that the current difference C is in the region L of the membership function of the current difference C in FIG. 3A and the current change rate ΔC is in the region S of the membership function of the current change rate ΔC in FIG. Of the current change rate ΔC and the rate at which the current change rate ΔC enters S as a smaller value. Therefore, the antecedent in the case of rule R1 indicates that it is satisfied at the rate of h1.

Similarly, in the case of rule R2 represented by (Equation 2),
The antecedent part indicates that it is established at the rate of h2. The same applies to the other rules R3 to R9.

Next, in STEP 6, the current difference C and the current change rate Δ are determined by the membership function of the execution part of the control rule.
The operation amounts of the first to fourth solenoid valves at C are obtained as follows. In order to obtain the manipulated variables F of the first to fourth solenoid valves, the constants at the conclusion are h1, h2,.
9, the manipulated variables F of the first to fourth solenoid valves are obtained by the height method, which is one of the point methods of (Equation 5), and output to the solenoid valve opening / closing control means 24. .

[0049]

(Equation 5)

Next, in STEP 7, it is determined from the value of the fuzzy inference means 23 that the liquid is not compressed, and in STEP 8,
Although the process proceeds to STEP 9, the same operation as that of the related art is performed, so that the detailed description thereof will be omitted.

Next, let us consider the cooling mode as the operation mode, in which the refrigerant in the refrigerant pump 10 liquefies from a gas state and the refrigerant pump performs liquid compression. In STEP7, it is determined from the value of the fuzzy inference means 23 that liquid compression is being performed, and the first solenoid valve 11 is driven to open (STEP10).
Is repeatedly driven to open and close (STEP 11). At this time, the second and fourth solenoid valves 12 and 14 are closed (STEP 1).
2).

That is, the flow of the refrigerant in the user-side refrigerant cycle 15 flows from the refrigerant pump 10 through the first solenoid valve 11, the user-side heat exchanging device 8, and the second auxiliary heat exchanging device 7, and the third flow. The solenoid valve 13 is reached. Here, since the third solenoid valve 13 is repeatedly driven to open and close, it is difficult for a large amount of liquid to flow and liquid compression is prevented.

In the heating mode, the flow of the refrigerant and the state of the refrigerant are reversed, but the basic concept is the same as that of the cooling, and a detailed description thereof will be omitted.

As described above, according to the present embodiment, the control device 1
7 is a first solenoid valve 11 and a third solenoid valve 13 during cooling.
By controlling the second solenoid valve 12 and the fourth solenoid valve 14 during heating, the liquid refrigerant flowing into the refrigerant pump 10 can be suppressed, so that the abnormal current pulsation of the refrigerant pump 10 is eliminated.

Since the drive current of the refrigerant pump 10 and the abnormal current pulsation of the refrigerant pump 10 have a correlation, the liquid refrigerant hardly flows to the refrigerant pump 10 by repeatedly opening and closing the solenoid valve at the inlet and outlet of the refrigerant pump 10. Thus, liquid compression can be avoided, and the life of the pump can be shortened and the vibration of the pipe can be prevented.

The value of the current difference calculating means 18 for calculating the current difference by subtracting a preset value from the detection value of the refrigerant pump driving current detector 16 and the rate of change thereof are calculated. The value of the differentiating means 20 is fuzzy inferred by a control rule based on an empirical rule extracted from the memory device, and based on the result, the solenoid valve opening / closing control means 24
Therefore, since the opening and closing degrees of the first to fourth solenoid valves are determined and controlled, the first to fourth solenoid valves can always be controlled with the optimum opening and closing degrees.

Further, since the refrigerant can always be optimally supplied to the user side cycle, the room temperature can be smoothly controlled without being disturbed, and comfortable air cleaning can be realized.

[0058]

As is apparent from the above embodiments, the cooling / heating system of the present invention comprises a heat source side refrigerant cycle in which a compressor, a heat source side heat exchanger, a decompression device and a first auxiliary heat exchanger are connected in a ring shape. have.

In addition, a second auxiliary heat exchanger formed integrally with the first auxiliary heat exchanger and exchanging heat, a user-side heat exchanger,
A refrigerant pump for sending refrigerant, a first solenoid valve installed in series between the refrigerant pump outlet and the user-side heat exchanger,
A second solenoid valve installed in series between the refrigerant pump inlet and the user-side heat exchanger, a third solenoid valve installed in series between the refrigerant pump inlet and the second auxiliary heat exchanger, There is a user-side refrigerant cycle in which a fourth solenoid valve installed in series between the refrigerant pump outlet and the second auxiliary heat exchanger is connected in a ring shape.

Also, a refrigerant pump driving current detector provided for the refrigerant pump and detecting a driving current of the refrigerant pump, and a detection value of the refrigerant pump driving current detector input to the first to fourth electromagnetic devices. A control device for controlling the valve is provided.

Further, the control device includes a cooling / heating mode detecting means for detecting cooling or heating, and a current difference calculating means for calculating a current difference by subtracting a preset value from a detection value of the refrigerant pump driving current detector. And a differentiating means for calculating and outputting a change rate of the output of the current difference calculating means in a very short time; and outputting the first to fourth information with respect to information on the output of the current difference calculating means and the output of the differentiating means. A memory device is provided for storing a control rule based on an empirical rule for obtaining the operation amount of the solenoid valve.

Further, a fuzzy logic operation is performed based on the output information of the current difference calculating means, the output information of the differentiating means, and the control rules taken out of the memory device to determine whether the refrigerant pump is liquid-compressed. Judge the first
Fuzzy inference means for calculating the operation amount of the fourth solenoid valve from the control unit, and electromagnetic valve opening / closing control means for determining and controlling the operation amount of the first to fourth solenoid valves based on the inference result performed by the fuzzy inference means And

With the above configuration, the control device controls the first solenoid valve and the third solenoid valve during cooling, and controls the second solenoid valve and the fourth solenoid valve during heating, so that the controller flows into the refrigerant pump. Since the liquid refrigerant can be suppressed, the abnormal current pulsation of the refrigerant pump is eliminated.

Since there is a correlation between the drive current of the refrigerant pump and the abnormal current pulsation of the refrigerant pump, by repeatedly opening and closing the solenoid valve at the inlet and outlet of the refrigerant pump, the liquid refrigerant hardly flows to the refrigerant pump 10 and the liquid compression becomes difficult. Can be avoided, and the pump life can be shortened and the vibration of the pipe can be prevented.

Further, the value of the current difference calculating means for calculating the current difference by subtracting a preset value from the detection value of the refrigerant pump drive current detector for the degree of opening and closing of the solenoid valve and the differentiating means for calculating the rate of change thereof. And fuzzy inference by a control rule based on an empirical rule taken out from the memory device, and based on the result, the opening / closing degree of the first to fourth solenoid valves is determined and controlled by the solenoid valve opening / closing control means. The first to fourth solenoid valves can always be controlled with an optimal opening / closing degree.

Further, since the refrigerant can always be optimally supplied to the user side cycle, the room temperature can be smoothly controlled without being disturbed, and comfortable air cleaning can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of a cooling and heating device according to an embodiment of the present invention.

FIG. 2 is a flowchart of an embodiment of the present invention.

FIG. 3A shows a fuzzy variable L with respect to a current difference C,
M, H membership functions μL (C), μM (C),
The characteristic diagram showing μH (C) is shown in (b) in which fuzzy variables S, Z,
B membership functions μS (ΔC), μZ (ΔC),
Characteristic diagram showing μB (ΔC)

FIG. 4 is a block diagram of a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 Heat source side heat exchanger 4 Pressure reducing device 5 1st auxiliary heat exchanger 6 Heat source side refrigerant cycle 7 2nd auxiliary heat exchanger 8 User side heat exchanger 10 Refrigerant pump 11 1st electromagnetic valve 12 2nd 13 Third solenoid valve 14 Fourth solenoid valve 15 User side refrigerant cycle 16 Refrigerant pump drive current detector 17 Controller 18 Cooling / heating mode detecting means 19 Current difference calculating means 20 Differentiating means 22 Memory device 23 Fuzzy inference Means 24 Solenoid valve opening / closing control means

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-62-272040 (JP, A) JP-A-4-158147 (JP, A) JP-A-5-118622 (JP, A) JP-A-5-118622 118623 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 1/00 F24F 11/02 102

Claims (1)

(57) [Claims] 1. A heat source side refrigerant cycle in which a compressor, a heat source side heat exchanger, a pressure reducing device and a first auxiliary heat exchanger are connected in a ring shape, and a heat exchange formed integrally with the first auxiliary heat exchanger. A second auxiliary heat exchanger, a user side heat exchanger, a refrigerant pump for sending refrigerant, a first solenoid valve installed in series between the refrigerant pump outlet and the user side heat exchanger, and the refrigerant pump A second solenoid valve installed in series between an inlet and the user side heat exchanger, a third solenoid valve installed in series between the coolant pump inlet and the second auxiliary heat exchanger, and the coolant pump A user-side refrigerant cycle in which a fourth solenoid valve disposed in series between an outlet and the second auxiliary heat exchanger is connected in a ring shape, and a drive current of the refrigerant pump provided for the refrigerant pump is detected. A refrigerant pump driving current detector, A control device for inputting a detection value of the output device and controlling the first to fourth solenoid valves, wherein the control device includes a cooling / heating mode detecting unit for detecting cooling or heating, and a refrigerant pump driving current detector. A current difference calculating means for calculating a current difference by subtracting a preset value from the detected value; a differentiating means for calculating and outputting a change rate of the output of the current difference calculating means in a very short time; For the information of the output of the means and the output of the differentiating means,
A memory device for storing a control rule based on an empirical rule for obtaining an operation amount of the first to fourth solenoid valves, information of an output of the current difference calculating means, an output of the differentiating means, and information retrieved from the memory device Fuzzy inference means for performing fuzzy logic operation based on the determined control rule, determining whether the refrigerant pump is performing liquid compression, and calculating the operation amounts of the first to fourth solenoid valves, and the fuzzy inference An electromagnetic valve opening / closing control means for determining and controlling the operation amounts of the first to fourth electromagnetic valves based on a result of the inference performed by the means.