JPS60178271A - Refrigerator with electric expansion valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a refrigerator, and particularly relates to an improvement in an expansion mechanism equipped with an electrically operated expansion valve whose opening can be adjusted.

(Prior art 2) Conventionally, as this type of refrigerator, for example,
As disclosed in Japanese Patent No. 47628, a thermoelectric electric expansion valve whose opening degree can be adjusted, a detection means for detecting the degree of superheat of the refrigerant at the outlet of the evaporator, and a signal from the detection means are received to determine the degree of superheat. A control means for controlling the valve opening degree of the electric expansion valve according to the electric expansion valve, and the degree of superheating of the refrigerant is maintained at a predetermined value by controlling the refrigerant flow chamber of the electric expansion valve. There is.

However, for example, when a refrigerator is started for the first time at the beginning of the cooling season, the electric expansion valve is initially fully opened, and then when the operation stabilizes, it is not opened properly. Since the position C is far away from the valve opening, the range of increase in the valve opening of the electric expansion valve that must be controlled during operation is relatively long. It takes time and lacks early stability of frozen OL power.

(Objective of the Invention) In view of the present invention IJ, l1li cal)jλ, the valve opening can be controlled relatively easily.As an electric expansion valve, for example, changes in the valve opening can be used to control the valve opening. We focused on the fact that there is a stepping motor type with a driving pulse number t: 1:1. When starting operation for the first time, such as at the beginning of the heating season, the valve opening degree of the electric expansion 4f is initially set to the appropriate value at start-up C, which is determined by a test or the like prior to the start of operation, and control is performed during operation. Reduce the range of increase/decrease in valve opening of the electric expansion valve that should be
``C'' is to achieve convergence and stability to the proper valve opening in a short period of time.

(Structure of the Invention) In order to achieve the above object, the structure of the present invention is as shown in FIG.
l), detection means (5 pieces) for detecting the degree of superheating or subcooling of the refrigerant after passing through the heat exchangers (2 to 5), and detecting means (5) for detecting the degree of superheating or subcooling of the refrigerant after passing through the heat exchangers (2 to 5); control means (55) for controlling the valve opening degree of the electric expansion valve (vl) according to the degree of superheating or supercooling of J3 is installed in the refrigerator, which is set to be held at the same value, and receives the signal from the operation start detection means (56) for detecting the start of the operating amount of the refrigerator (56). a reference position adjusting means (57) for emitting a reference position signal by positioning the electric expansion valve (Vl) at a fully open or fully open opening reference position; The electric expansion valve (Vl)
and initial setting means (58) for positioning the valve opening degree to a preset initial setting value. As a result, when the refrigerator starts operating for the first time at the beginning of the cooling or heating season, the valve opening degree of the electric expansion valve is first set to the fully open or fully open position 1ij- (=jtel, the current valve distance There is a method in which the electric expansion valve is set in advance and the initial setting value is set to the initial setting value after determining the difference in valve opening between the initial setting means and the initial setting means.

(Effect of explanation) Did you do it?
I. In most cases, the valve opening degree of the electrically operated expansion valve is determined based on whether it is open or closed i1. Since the position (tl) is initialized to the preset initial setting value, convergence control to the appropriate valve opening of the electric expansion valve can be performed satisfactorily in a short time. There are some methods that can effectively improve the convergence stability of the opening and, by extension, the early stabilization of the refrigeration force (1u force).

(Example) Hereinafter, an example of the present invention will be described based on the drawings below in Figure 2.
(Explain in detail.

Fig. 2 shows an example in which the present invention is applied to a pump-type air-conditioning/heating water heater. .

(D> is an indoor unit installed in a different room in the room, (E) is a hot water tank unit, and the outdoor unit (Δ) has a compressor (1) inside and a heat exchanger on the heat source side. (2), as well as an indoor unit (B
), (C), and (D> each have an air conditioning load side heat exchanger (3) inside.

C includes (4) and (5). In addition, the hot water tank unit (
E) is a hot water storage tank (6) that stores water therein, and a heat exchanger 1 on the heating load side that heats the water stored in the hot water storage tank (6). ll
! (7), and a pump (P) that circulates the water stored in the hot water storage tank (6) to the hot water supply load side heat exchanger (7).

In the above outdoor units 1 to (Δ), (SVl) and (SV2) are four-way switching valves that switch as shown by solid lines when OFF and switch as shown by broken lines when ON, respectively.
SV3) is connected from the receiver (8) to the hot water supply load side heat exchanger (7
) is an electromagnetic on-off valve that allows the refrigerant flow to a′ [(V+, (V,!), (V3).

(Va)J5J:bi(\/s> is a stepping motor-type electric expansion valve that can be adjusted to open and open, respectively.
Each of the lightning expansion valves (■1) to (■5) uses a control signal generated by the CPU (42), which will be described later, in which the change in the valve length is 1:'1 in the number of driving pulses of C. There is a corresponding one.

In addition, (Kings 1 to 11) connect the liquid pipe (15> between the electric expansion valve <V4) and the receiver (8) and the waste pipe (23) returning to the compressor (1). .Insert the return tube (27) into the first bypass pipe (36) with the gear rib (27) interposed.
23> The first warm melon sensor with Narmister J installed on the side, and the evaporation 8+A in the frozen soycle
('T1), and < T I-
12> is the 44-pass gas pipe (16) between each air conditioning load side heat exchanger (3) and the four-way switching valve (SV2>), and each of the electric expansion valves (V+), -(V2>, Branch liquid piping (2) on the indoor unit (B), (C), <D) side of (V3)
0), (21).

(22). The connection between the auxiliary condenser (37) and the 17th pillar cove (28) is connected to the second bypass pipe (39), which is equipped with an auxiliary condenser (37), a capillary tube (28), and a check valve (38). A second temperature sensor consisting of a thermometer is installed between the air conditioning load side heat exchanger (3) during heating operation.

This is to detect the condensation temperature (T2) of (4) and (5) on the outdoor side.
I-410) are the third to tenth temperature sensors which are thermistors J in the same way as above, and
Branch gas piping (17) to (19) between temperature sensor (T+-13) to (King 1-15>+) and air conditioning load side heat exchanger (3) to (5) and four-way switching valve <5V2, respectively. ), and detects the refrigerant temperature of the low-pressure gas refrigerant <1-3), <T4), and (T5) during cooling operation and cooling hot water supply operation, and the sixth to eighth temperature sensors (TI-16)
~ (T I-18) are respectively t and the air conditioning load side heat exchanger (
3) Branch liquid piping (2Q) between (5) and receiver (8)
) to (22), the refrigerant temperature (Te ) of the high-pressure liquid refrigerant after condensation and liquefaction during heating operation and heating operation, (T7
), (TB), and the temperature sensor (TI-19) detects the refrigerant temperature (Ta) of the return gas pipe (23) to the compressor (1).
Furthermore, (T H10) is the discharge gas pipe of the compressor (1)
It detects the refrigerant temperature (TIO) at 24°C. J
: When the air conditioning load side heat exchangers (3) to (5) each act as an evaporator, the first temperature (T I
~11) J second evaporation humidity (1-+), ・IJ and third
~5th temperature 1 good temperature 1 no (T if 3) ~ (T l-
15)) J, each air ♂ 1 negative side heat exchanger <3)・-
(5) Refrigerant temperature of low pressure gas refrigerant after passing (King 3), (T
4), <1-5> is detected, and conversely, when each air conditioning load side heat exchanger (3) = - (5) acts as a condenser, the The condensing temperature (downward) is determined by J5J: and the 6th and 8th temperature sensors (T' Ll 8 >). 5) Refrigerant temperature of high-pressure liquid refrigerant after passing through: 1<Te), (1'7), (-
1-a) At the same time as detecting 9), the heat source side heat exchanger 2)
If it acts as a seafood organ, the first thirst is caused by good senna (-
]) to 11), the evaporator 1
The refrigerant temperature (TB) of the low-pressure gas refrigerant after passing through the heat source side heat exchanger 2 is detected by the temperature refrigerant (1-19). In the figure, (29) is the capillary tube, (30> is the heating load side heat exchanger (7)
a one-way valve that allows refrigerant flow from the receiver (8) to the receiver (8);
(3,1) is an accumulator, and (32) to (35) are closing valves.

Then, the above 10 ([1,1 temperature sensor (T)-11
) to (THl0)l, respectively, as shown in FIG. V5
) to control rJII'! It is connected to the control circuit (, 40) so that signals can be sent and received. As shown in FIG. 3, the control circuit (40) internally selectively receives temperature signals from ten temperature sensors (THl) to (THlo) through a multiplexer (41). 3.
Three types of operation mode signals (cooling, hot water supply, heating operation command signals), set room temperature signal, actual room temperature signal, and hot water storage tank unit (E) from each indoor unit (B) to (D)
a CPU (42) that receives a hot water supply operation command signal from the
Compression (when the number (1) starts 111, the driving mote, indoor unit, and unit 1 (1',) ... Initial setting 1 of the valve opening degrees of the above-mentioned four electric expansion valves (Vl)-(V4)
It is equipped with a ROM (ROM<43) that can store ``1'' in advance.

Then, the CPU (-42) controls the compression (number of degrees) in response to the operation mode signals from the three indoor leeks 1-(B) to (D), the actual room temperature signal, and the heating operation command signal. Ku1
) is controlled to 0N=OFF, and the four-way switching valve (SVl), (SV2), and electromagnetic opening/closing valve ↑(
SV3) Four electric expansion valves (Vl) ~ (Indoors where the Vr is controlled as shown in the first line of the same table during cooling operation and is operated to issue the first-door signal) - Nitsu l-11111 (below,
(simply referred to as the operation side) single heat exchanger on the air conditioning load side (3) to (
The heat fTi absorbed from the room in step 5) is transferred to the heat source side heat exchanger (2).
), each air-conditioning load-side heat exchanger (3) to (
5) The degree of superheating of the refrigerant of C, that is, the temperature difference of 1 attenuation of the refrigerant temperature <1-
3-T+ ), (T4-T+ ), (1-s -T+
) are adjusted to the set superheat degree (SHo + ) using the corresponding electric expansion valves (■1) to (V3), while during cooling hot water supply operation, the air conditioning load on the operating side is controlled as shown in the second line of the same table. The heat absorbed from the room by the side heat exchangers (3) to (5) is radiated to the stored water in the hot water storage tank (6) by the hot water supply load side heat exchanger (7) to heat the stored water (hot water supply). At the same time, the temperature difference in the degree of superheating of the refrigerant, that is, the humidity of the refrigerant in the air-conditioning load-side heat exchangers (3) to (5) that act as the evaporators (T3-T+ >, ( T4-1-+ >,
(T5-T1) in the same way as above, set superheating to 1M (S l-
11) 2) When adjusting 2), and during hot water supply operation, refer to Table 3 in the same table.
The heat exchanger (2) on the heat source side absorbs heat from outside by controlling the heat exchanger (2) on the heat source side (2) to transfer the heat (1) to the hot water storage tank (7) on the hot water supply load side.
6) While supplying hot water by dissipating heat to the stored water inside, the refrigerant superheating degree, that is, the temperature difference (TsTl) of the refrigerant temperature in the heat source side heat exchanger (2) which acts as the evaporator, is controlled by an electric expansion valve <V4). The superheat degree (St-103) is adjusted to the set superheat degree (St-103), and during heating operation, the control is performed as shown in the fourth line of the same table, and the heat source side heat exchanger (2
), the amount of heat absorbed from the outside is radiated indoors by the air conditioning load side heat exchangers (3) to (5) on the operation side, and the heat is radiated indoors to the corresponding room (!:
While heating, the evaporator acts to superheat the refrigerant in the heat source side heat exchanger (2), that is, the temperature of the refrigerant increases. )rMQ constant superheating 1m
(S1-1o4) and the degree of supercooling of the refrigerant in the air conditioning load side heat exchangers (3) to (5) which act as the condensers, that is, the difference in refrigerant temperature <T2-T6).

(1-277) and (T2 1-a) are respectively corresponding crane electric expansion valves (Vl) to (V3)rH'i! Adjust to constant supercooling of 7.11 degrees (SCo+). In addition, during heating) 1 turn W tl, -, t, L, each room - l - chive 1 ~ (
Each indoor noan (3a >
, (/li+ >, (5a). In this case, the air conditioning load side heat exchangers (3), (4), (5
), there is very little heat dissipation in the electric expansion valve (■1
) to (v3) are fully opened, while controlling the loss of lj1 chamber capacity to the extent that it does not pose a practical problem by adjusting it to the set supercooling level (SCO2) during I!21 chamber operation.
This is to prevent liquid accumulation as much as possible. In addition, in Figure 3,
(45) to (49) are each five Ti electric expansion valves v
l) to <v5), (50) is the CPU
Five electric expansion valves (vl) to (V
5) is a multiplexer that distributes a drive pulse (described later) as a valve opening degree control signal to the corresponding one; (51) is a scum shortage indicator light that lights up when the refrigerant flow rate is insufficient; and (52) is a power plug. Further, the electric expansion valve (5) is opened when the operation of the refrigerator is stopped and acts as a pressure equalization expansion valve that balances the pressure angle between the high pressure side and the low pressure side of the compression 1 (1).

Next, the electric expansion valve (Vl) ~ by the CPU (42>)
The valve opening degree control (T4) will be explained based on the flowchart of FIG. J5, during heating operation, all four electric expansion valves (vl) to (T4) are controlled in valve opening as shown in the table above, and since the entire control of this embodiment can be explained, the flow during heating operation will be explained below. Explain. This flowchart shows the operation mode of the heating operation from one of the three indoor units (starting in response to No. g, first in step 81, the heating operation mode is started from one of the three indoor units).
After determining the ℃ operation mode and the number of operating rooms based on the operation mode signal received from at least one of them and the number of receptions thereof, in step $2, J5 operates four electric 8 expansion valves (V 1 )''-. A drive pulse as a valve opening control signal is generated in the direction of closing the openings of 1 to (T4), and each electric expansion valve (Vl) = (\//I) is fully opened. The position E] moves to the opening reference position.Then, in step S3, each 7R dynamic expansion valve (v
l) - (V7I) Read the initial setting value of Benma 1 woman,
Between the initial setting value and the above value, a drive pulse of the number of pulses is applied to the corresponding electric expansion valve (T1
) to (T4), and output the valve opening degree to each initial setting 1.
Then, in step $4, the valve is instructed to be held for a predetermined period of time (for example, 5 minutes) corresponding to the transient time until the operation becomes stable, and then in step S5. Start the compressor (1) for the first time.

Next, in step S6 d3, the temperature at 10 points of temperature Ia ('I-1-11> from (i-1-110>) is based on the temperature at 10 points in Figure 2). (T1) ~
After reading (-rho), in step S7, the compressed (1) refrigerant waste temperature 1 good (1°10) is compared with a predetermined value (-rho) corresponding to the abnormal rise. However, in the abnormal operation 114 of YES, which is smaller than the predetermined 1ffl (T' L M ), step Sa (set superheat degree (St-1o+ to 0) corresponding to the operation mode
4) to lower the refrigerant gas discharge temperature (Too),
After waiting a predetermined time for this state to stabilize for 1 J, the process proceeds to step S9, while in the case of NO normal operation in which the refrigerant gas discharge temperature (TIO) is below the predetermined value (TcM), the process immediately proceeds to step S9.

And step S! The degree of superheating of the actual refrigerant in the heat exchanger (2) acting as an evaporator in 1 < S l
-1> based on the above temperature difference (Ts-1-+), and the actual degree of supercooling (SC) in the heat exchangers (3) to (5) acting as condensers is calculated based on the temperature difference (Ts-1-+). Difference (Tz −Te
), (T2-Ty >, (T2-T8'), the actual superheat +1 is determined in step S1o.
(S I-1) J5 and actual supercooling 111 (SC
) and the corresponding set superheat degree (SHo4) and set supercooling Ia (SCo1~.

Compare the size with 2). If both of them do not match (No), the process proceeds to step S o, and in the step SI+ [actual superheat 1 m, if (S The actual supercooling degree (SC) is the set supercooling degree (SCo i
-o z ), it is determined that the refrigerant flow rate is low and the corresponding electric expansion valve<vi>-・kuV/I
>, the number of C pulses is increased and a drive pulse is output as a closing signal to control the valve opening, while conversely, the setting superheat m (81 -l
o 4) and the actual degree of supercooling (SO
) is smaller than the set supercooling degree (SCo+~02), it is determined that the refrigerant flow rate is large and the number of pulses is reduced for the corresponding electric expansion valves (V'1)~(v4). After outputting a drive pulse C as a closing signal and reducing the valve opening degree, the process proceeds to step 812. On the other hand, step 810 (”
The actual superheating m (S l-Od3.J, and the actual supercooling person 1lla (SC) correspond to the corresponding settings (fl (
St-1o = ).

In the case of YFS equal to (SCI]1 to []2), it is determined that the refrigerant flow rate is appropriate, and Wi et al.
Proceed to step 2.

Wamoi C, superheat degree control 111 in step SI2
It is determined whether the valve of the electric expansion valve T (V/l) in the first process is open, and if the answer is No, it is determined that the degree of superheating is being properly controlled, and the process returns to Step S6, while the valve is opened. If the degree of superheating is YES, the degree of superheating is extremely high, and if it is determined that there is a shortage of refrigerant gas (gas shortage), proceed to step S.
Proceed to step 13. Since it is a heating operation, first, step S+s is performed to determine whether there is a gas shortage due to liquid accumulation in the indoor units (B) to (D) on the stopped side.
In this case, lower the supercooling setting of 1 m (SCo2) in the indoor units (B) to (D) on the heating stop side, and correspondingly increase the opening of the electric expansion valves (vl) to (v3) by a certain amount. Start collecting the refrigerant that has accumulated. Then, after waiting a sufficient time for recovery, in step S16, the valve opening degree of the corresponding superheat degree (electric expansion valve < V 4 controlling St-(o, +)) is determined again, Not fully openN
o, it is determined that the degree of superheating has returned to proper control, and the process returns to C step S6. On the other hand, in the case of YES, which indicates that the degree of superheat is still fully open, it is determined that there is a gas shortage, and the compressor (
In addition to stopping the operation of 1), the out-of-gas display ￥]'(
51) is turned on.

On the other hand, in the case of cooling operation, the operation of the compressor (1) is immediately stopped in step S14, and the out-of-gas indicator light (51) is turned on.

Then, (indoor unit h (B) ~ (D) ip on the q stop side
When R et al. receives a new operation mode No. 8, it interrupts the flow [1-set] in Figure 4 and goes to the flow \-- in Figure 5.
In step S, the type of operation mode is determined, and in step S+a, the number of driver's cabs is determined. Read out the 59 fixed vessel from the ROM (43) and use the electric expansion valve ↑ (Vl) corresponding to the air conditioner 1'lVi side heat exchanger (3) to <5) to start operation anew.
= (\/3) valve opening to the above initial setting 1iff for the first time
fl Settings. Thereafter, an instruction is given to hold this valve opening degree for a predetermined period of time until the refrigerant flow becomes stable, and the process returns to step 86 in FIG.

Therefore, in step 89 of the flowchart of FIG. 4, the degree of superheat (Sl-1) of the refrigerant after passing through the heat source side heat exchanger (2) which acts as an evaporator during heating operation is determined by the temperature difference (T).
The hot water supply load side heat exchanger (3'-), (4), (5) acts as a condenser.
) The degree of subcooling (SC) of the refrigerant after passing through the temperature difference (
T2 T6).

(T2-T7'), (T2-Ta) constitutes a detection means (59) that detects based on.

Also, by steps S +o and S o in FIG.
Actual superheat degree (S) in heat exchangers (2), (3) to (5)
H) and the actual degree of subcooling (SC) are respectively equal to the set degree of superheat (SHoa) and the set degree of subcooling (SCo+), the temperature difference (T9-TI) of the refrigerant temperature,
(T3-TI), (T4-T, +), (T5-1
-+), (T2-76).

(1-2-Ty) and (T2-Ts), a control means (55) is configured to control the valve opening degrees of the corresponding electric expansion valves (Vl) to (4).

Furthermore, when the CPU (42) receives the operation mode Shintan from at least one of the three indoor units (B) to (D), the flowchart in FIG. Is it cold at the beginning of the season? ! 111
The operation start detection means (56) is configured to detect the initial operation start of tJ&, and when the refrigerator starts operation for the first time, that is, the flowchart shown in FIG. The corresponding electric expansion valves (Vl) to (V4) are positioned at position 1 (above the opening degree at which the valve opening is fully open). (57).

Furthermore, after the processing operation in step S2, step S3
In other words, in response to the reference position 1 of the means (57), the corresponding electric expansion valves (Vl) to (V4) are adjusted in step S1. Operation mode with each opening degree set in advance in ROM<43):
The initial setting means (58) is configured to set the position to the initial setting value according to the total number of operations.

However, in the above embodiment Jj, when the refrigerator starts operating, the stepping motor electric expansion valves (Vl) to (v4) whose degree of superheating or degree of subcooling is to be controlled are controlled by their valve opening degrees. After the valve is positioned at the valve opening position where -1 is fully closed (>I l), the valve is set in advance to be appropriate when starting the compressor (1) according to the operating mode and the number of operating rooms. ROM (43
), so at the beginning of the initial operation, such as at the beginning of the cooling or heating season, the initial valve opening of the electric expansion valve may deviate greatly from the appropriate valve opening when operation is stable. Even if the valve opening is in the same position, the valve opening will be well converged and stabilized in a short time. It is possible to effectively achieve this goal.

In the above embodiment, the initial settings of the electric expansion valves (vl) to (■4) are performed using the first initial setting stored in advance in the ROM (43). 3
A RAM is added to the control circuit (40) shown in the figure, and the current valve opening degrees of the electric expansion valves (Vl) to (V4) are rewritten and memorized at the time of change. If $3 is initially set to the valve opening stored at the time of the previous stop of operation as shown in step S'3 in Fig. 6, convergence to the appropriate valve opening will be more stable! It can be done in 1111 hours.

Further, in the above embodiment, at the start of operation of the refrigerator, the electric expansion valve (Vl) to (V/l
) was once placed at the opening reference position +11 where the valve opening is fully opened, but instead, it may be placed at the opening reference position where the valve opening is fully opened. Of course,
During operation, it is not always necessary to control both the degree of superheating and the degree of supercooling, and only one of them is sufficient.

Furthermore, in the above embodiment, when the electric expansion valve (■4) under control is fully open during heating operation, the electric expansion valve corresponding to the indoor connit (]3) to ・(])) on the stop 1- side is Set the valves (vl) to (v3) to reduce supercooling (SCO2) by a specified opening (Jζ) to collect the refrigerant accumulated there, but in addition to - Electric expansion valve (
vl) to (v3) may be forcibly turned on for a predetermined period of time to recover the accumulated refrigerant.

[Brief explanation of drawings]

Figure 1 shows the structure of the present invention.
6 to 6 show embodiments of the present invention, FIG. 2 is a refrigerant piping system diagram when applied to an air-conditioning/heating water heater, FIG. 3 is an electric circuit diagram showing the internal configuration of the control circuit, and FIGS. Fifth
The figures are flowcharts 1 to 1 showing the operation of the CPU, respectively.
FIG. 6 is a flowchart showing a modification of the operation of the CPU. (2) to (5)...Heat exchanger, (T8.1) to (T19)...Temperature detection means, (Vl) to (V4)...
・Stepping motor type electric expansion valve, (55)...control means, (56)...-operation start detection means, (57)
)... Reference positioning means, (58)... Initial setting means. Figure 6 Figure 5

Claims (1)

[Claims] (1) An electric expansion valve (Vl to V4) whose opening degree can be adjusted,
Degree of superheating or subcooling of the refrigerant after passing through the heat exchanger (2 to 5) J
a detection means (59) for detecting 1 degree;
9) From (), the degree of superheating or subcooling of the refrigerant, 1
It of the electric expansion valve (V1 to V/I) according to the degree
I! A control means (55) for controlling the degree of D is set to l+i5,
- In a refrigerator in which the degree of superheating or subcooling of the refrigerant in the heat exchanger (2 to 5) is maintained at a predetermined level, the first time of operation of the refrigerator is detected. The detection means (56) receives the signal from the operation start detection means (56) and positions the valve openings of the electric V and tension valves (Vl to V4> at all or all opening reference positions). ↑ (Vl);
A refrigerator equipped with an electric expansion valve characterized by comprising initial setting means (5B) for setting the valve opening degree of V4) to a preset initial setting value.