JPS62284167A - Refrigerator - 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 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a refrigeration system, and more particularly, a hot gas valve, a condenser, and an expansion mechanism are bypassed to supply hot gas to an evaporator. The present invention relates to a refrigeration system equipped with a hot gas bypass path that performs capacity control by bypassing the hot gas.

(Prior Art) Conventionally, hot gas discharged from a compressor is bypassed through a condenser and an expansion mechanism to an evaporator to control the temperature of the blown air. 12
This is known as shown in Japanese Patent No. 2883.

This conventional example has a compressor (
The condenser (C) and expansion valve (EV) are bypassed to the high pressure gas pipe (B) connecting the discharge side of A) and the inlet side stone of the condenser (C), and the inlet side of the evaporator (E) is Connect the hot gas bypass path (H) that connects to this hot gas bypass path (
'H') is equipped with a hot gas valve (HV), and
)? 1. The evaporator (E) has a supply sensor (S) that detects the temperature of the air blown out from the evaporator (E).
S ), and this supply center '−< s
Input the temperature of the blown air detected in step s), and output an opening/closing signal to the hot gas valve (HV) i1M by comparing this blown air temperature with the set temperature of the blown air. ) A controller (CR) is provided to control the temperature of the air in the evaporator (E) by controlling the hot gas valve (HV) to a predetermined opening degree.

(Problems to be Solved by the Invention) As described above, based on the blowing air temperature detected by the supply sensor (SS), the controller (CR) controls the hot gas valve (HV) by comparing it with the set temperature. When controlling, when the blowing air temperature is controlled by the controller (CR), the blowing air temperature is controlled by the controller (CR).
When the upper limit of the control temperature range is reached for the set temperature set in Immediately after the start, the temperature of the blown air rises and exceeds the upper limit, and the operation is switched to full cooling again. From then on, this state is repeated and becomes stable.

For this reason, there is a problem in that it takes a long time to stabilize the control during pull-down.

In addition, at full down when this problem occurs, in addition to the first pulldown after turning on the power and starting operation, the blowing air temperature changes when changing the set temperature and checking the operation. For example, S
``Pull-down when the temperature of the Suita air is 5℃ or more relative to the set temperature even after 30 minutes have passed after the end of the defrost operation, and when the Suita air temperature is 5℃ or more relative to the set temperature for 30 minutes or more. It includes time.

SUMMARY OF THE INVENTION An object of the present invention is to shorten the time required to stabilize the control during pull-down even when the heat capacity is large.

(Means for Solving the Problems) In order to solve the above problems, the present invention has the following objectives:
The hot gas valve control based on the outlet air temperature, which is affected by the internal heat capacity, is stopped until the intake air temperature reaches the temperature difference between the set outlet air temperature and the temperature during stable operation. The system detects whether the wall surface, etc. has been cooled to near the set temperature by detecting the suction air temperature, and then performs normal control using the blowout air temperature. ? Go 181L Kugitokai/Q Q) No re edition edition (5)
and a hot gas bypass path (8) that bypasses the hot gas to the evaporator (4), and controls the temperature of the air blown from the evaporator (4) by opening and closing the hot gas valve (1o). The evaporator (4)
) supply sensor (SS) that detects the temperature of the air blown out of the
, a blowout air temperature setter (21), a means (22) for comparing the blowout air temperature detected by the supply sensor (S ) is provided with a controller (20) having an output means (23) for outputting an opening/closing signal to the evaporator (4), and a return sensor (RS) for detecting the temperature of the intake air of the evaporator (4).
) and the supply sensor (S S) are provided, and at the time of pull-down, the output means ( 23) is provided with an output stopping means (24) for stopping the output.

(Function) During pull-down, the supply sensor (SS) is switched to the return sensor (RS), and until the intake air temperature reaches the temperature difference between the set temperature of the discharge air temperature and the temperature during stable operation, the discharge air temperature is Even if the set temperature is within the control range, the opening/closing control of the hot gas valve (10) is stopped, and the capacity control by the hot gas valve (10) is not performed until the heat capacity inside the refrigerator becomes small. This system detects that the heat capacity decreases depending on the air temperature, and then performs control based on the temperature of the blown air, which shortens the time it takes to stabilize the control during pull-down.

(Example) What is shown in FIG. 3 shows a refrigerant piping system of a container refrigeration system, and is basically the same as the conventional example shown in FIG.

That is, in Fig. 3, (1) is a compressor, (2) is an air-cooled condenser, (3) is a water-cooled condenser, (4) is an evaporator, and (5) is a sensor with a temperature sensing part (5a). The thermal expansion valve (6) is an accumulator, and these devices are connected by refrigerant pipes (7) to form a refrigeration cycle in which the evaporator (4) cools the air inside the refrigerator, and the compressor A high-pressure gas pipe (71) connecting the discharge side of the machine (1) and the inlet side of the air-cooled condenser (2) is connected to a high-pressure gas pipe (71) that connects the hot gas to the condenser (2).
(3) and the temperature-sensitive expansion valve (5) to bypass the evaporator (4).
), and its outlet side is connected to the low pressure liquid pipe (72) between the expansion valve (5) and the evaporator (4), and this hot gas bypass A hot gas valve (10) is interposed at the connection portion of the passage (8) to the high pressure gas pipe (71).

In the embodiment shown in FIG. 3, a solenoid valve (SV,') is provided in the high-pressure liquid pipe (73) between the condensation ti ('3) and the expansion valve (5), which closes until the defrost operation is instructed to start. On the other hand, on the upstream side of this solenoid valve (SV), that is, on the condenser (3) side, solenoid valves (SVl) are installed at regular intervals, and these solenoid valves (SV,)
In the liquid pipe section between the solenoid valves (SV, ), a certain amount of refrigerant is metered out of the refrigerant to be trapped by pump-down operation, and with the solenoid valve (SV, ) closed, the solenoid valve (SV, ) is closed. A defrost circuit that defrosts a certain amount of refrigerant by opening the compressor (1);
hot gas valve (10), hot gas bypass path (8),
The air flows out into a defrost circuit consisting of an evaporator (4) and an accumulator (7).

Moreover, in the one shown in FIG. 3, a drain pan heater (11) is attached to the evaporator (4), and a three-way solenoid valve (SV) is installed in the hot gas bypass path (8).
is installed to supply hot gas to the drain pan heater (11).
It is possible to select whether the water is led to the evaporator (4) via the evaporator or directly.

Further, the pressure equalization pipe (5b) of the expansion valve (5) is connected to the low pressure gas pipe (74), but there is a part in the middle of this pressure equalization pipe (5b) connected to the hot gas bypass path (8). ,
A control passage (12) is provided for guiding a portion of the hot gas to the pressure equalization pipe (5b) and forcibly reducing the opening degree of the expansion valve (5) by the pressure of the hot gas. A pressure equalizing pipe (5b) is selectively communicated with one of the hot gas bypass passage (8) and the low pressure gas pipe (74) at a connection portion of the passage (12) to the pressure equalizing pipe (5b);
A three-way solenoid valve (SV4) is provided to cut off communication with the other side.

In Fig. 3, (i3) is a dryer, (14) is a liquid indicator, (15) is a manual closing valve, and (16) is a liquid indicator.
) is an indoor fan attached to the evaporator (4), and (17) is an outdoor fan attached to the air-cooled condenser (2).

The hot gas valve (10) is mainly an electric three-way valve, and the hot gas bypass path (8) is proportional to the voltage.
), a proportional control valve that enables the valve opening to be varied from 0 to 100%, controls the hot gas bypass amount to the evaporator (4) to adjust the capacity, and at the same time maintains the opening to 100% during defrost operation. This hot gas valve (
10) The electric part (20M) is a controller (to be described later) (
20), the valve opening degree is controlled by PTD.

Therefore, in the above configuration, a supply sensor (SS) for detecting the temperature of the blown air is provided on the outlet side of the blown air in the evaporator (4), and a return sensor (SS) for detecting the temperature of the suction air is provided on the inlet side. In addition to providing a sensor (RS), a setting device (21) for setting the air temperature, and a blowing air temperature (S) detected by the supply sensor (SS) are provided.
T) and the set temperature (SP) of the blown air, and the controller (20) outputs an opening/closing signal to the hot gas valve (10) based on the comparison result to control the operation of the refrigeration system. be.

The operation control circuit using the controller (20) is as shown in FIG.
is a power supply input section (V) connected to a power supply via an operation switch (3-88), and a comparison means (22) shown in FIG.
It is equipped with a central processing circuit (CPU) and a memory circuit (M) constituting an output means (23) and an output stop means (24), and the input side (I) is equipped with the supply sensor (
SS) and return sensor (R9) are connected, as well as a defrost timer (2D) and a temperature sensor (TH) that detects the completion of defrost, and the output side (0) is connected to the hot gas valve ( 10) Electric part (2
0M) and the solenoid relays (2OR,) to (2OR4) of the solenoid valves (SV,) to (SV,), and also connect the high pressure switch (83H) and the low pressure switch (63L).
, an overcurrent relay (51c), a compressor motor start/stop control circuit in which a compressor (1) protective relay (49c) and a compressor motor electromagnetic switch (88c) are connected in series, and an indoor fan (16). and each motor (88) of the outdoor fan (17)
EF) (88CF) are connected to each other.

Therefore, in the above configuration, when performing refrigeration operation, the temperature of the air cooled in the evaporator (4) is adjusted by setting the air set temperature (SP) with the setting device (21).
), and the supply sensor (
Based on the temperature difference (ST-8P) between the blowing air temperature (ST) detected by SS) and the set temperature (SP),
) The opening degree of the gas valve (10) is controlled from 0 to 100%, and the hot gas according to this opening degree is bypassed. During pull-down or pre-use investigation (Pre
When switching the set temperature (SP) to check the operation during trip inspection), the blowing air temperature (ST
) is 5'C or higher relative to the set temperature (S P), or even if 30 minutes have elapsed after the defrost operation has ended, the blowing air temperature (ST) is 5'C or higher relative to the set temperature (S P).
In the above cases, and during full down when the blowing air temperature (ST) is, for example, 5°C or more relative to the set temperature (S P) for 30 minutes or more, the supply sensor (SS) is switched to the return sensor (R3). Then, the outlet air temperature (ST) is increased until the suction air temperature (RT) reaches the temperature difference (RT-8P) during stable operation from the set temperature (SP).
The opening control of the hot gas valve (10) based on the temperature difference between the hot gas valve and the set temperature (SP) is stopped, and full cooling operation is continued.

When the intake air temperature (RT) becomes the temperature difference (RT - SP) with respect to the set temperature (SP), the inner wall surface of the refrigerator is cooled to near the set temperature (SP), and the heat capacity inside the refrigerator is increased. The temperature difference when the temperature decreases is usually set to +2°C as shown in the control pattern shown in FIG.

Also, when the temperature difference is 2°C, the blowing air temperature (
ST) varies depending on the capacity of the evaporator (4),
If the capacity is large, the set temperature (S
This is lower than the lower limit of the control range for P). Therefore, when the suction air temperature (RT) becomes the temperature difference mentioned above with respect to the set temperature (SP), the operation of the compressor (1) is stopped. When the capacity is small and the temperature difference between the suction air temperature (CRT) and the set temperature (SP) is 2'C, the blowout air temperature (S
If T) is within the control range for the set temperature (SP), the blowing air temperature (
What is necessary is to shift to the opening degree control of the hot gas valve (10) based on the temperature (ST) of the hot gas valve (10), but even if the blown air temperature (ST) is at the lower limit of the control range of the set temperature, 1
) without stopping the operation of the hot gas valve (10
) may be controlled to 100%.

Furthermore, the temperature of the air blown from the hot gas valve (10) (ST
) is performed based on the temperature difference between the blowing air temperature (ST) and the set temperature (SP), but if this temperature difference is lower than the lower limit of the control range (e.g. -1.5°C), The opening degree of the hot gas valve (10) is set to 100%, and the compressor (1) is stopped when the temperature difference increases further than the lower limit (for example, -6°C).

Furthermore, in the above explanation, the control range for controlling the opening of the hot gas valve (10) is different between when controlling in the downward direction and when controlling in the upward direction, and usually when controlling in the downward direction. The range is +1°C≧5T-SP>-1,5°C, and the control range in the upward direction is -1,5°C: aST-8P<
It is set to 2.5″C.

Next, the refrigeration operation of the refrigeration system configured as described above will be explained according to the flowchart shown in FIG. 4.

First, the set temperature is set to 13°C or more, for example 0°C, using the setting device (21), so that the blowing air temperature (ST) detected by the supply sensor (SS) and the set temperature (SP) are A comparison operation is performed in the central processing circuit (CPU) of the controller (20).

Then, the set temperature (SP) and the blowing air temperature (ST)
When the temperature difference (ST-3P) between ℃
If the temperature is higher than that, set the indoor fan (16) to low speed, and
When the temperature is 15° C. or lower, it is driven at high speed. The speed control of these indoor fans (6) is to prevent overload operation.

By driving the compressor (1), the temperature of the blown air (
ST) decreases, but this blown air temperature (ST
) is 5°C or more relative to the set temperature (S
Based on this judgment, the supply sensor (SS) is switched to the return sensor (RS), and the intake air temperature (RT) detected by the return sensor (R8) and the set temperature (S P) are The comparison calculation is performed by the central processing circuit (CPU) 20).

Then, the suction air temperature (RT) and the set temperature (SP)
The temperature difference (RT -5P) between
When the temperature difference is 2°C or more, for example, when the temperature difference is considered to have cooled the air to near the hot gas valve (SP), the hot gas valve (10
), that is, full cooling operation is performed at 0% opening.

In addition, if the temperature/degree difference (RT - S P) becomes lower than 2°C, even if the heat capacity of the internal wall surface is large, the set temperature (SP
), if the temperature becomes lower than this temperature difference (2'C), the return sensor (R3) is switched to the ply sensor (SS) again, and the discharge air temperature (ST ) based on which the operation is controlled.

In addition, in the flowchart shown in FIG. 4, the temperature difference (
Although the compressor (1) is stopped when the temperature (RT-3P) becomes lower than 2°C, the opening degree of the hot gas valve (10) may be controlled to 100% as described above.

Furthermore, the compressor (1) is stopped in relation to the capacity of the evaporator (4), and the temperature difference CRT-S P)
is set at 2°C, and the blowing air temperature (ST) corresponding to this temperature difference exceeds -1.5°C, which is the lower limit of the control range. If not, there is no need to stop the compressor (1) as described above, and you may proceed to the opening control flow (I) of the hot gas valve (10), which will be described later.

Furthermore, when the compressor (1) is stopped, the temperature of the blown air (ST
) increases, and the outlet air temperature (ST) and set temperature (S
If the temperature difference (ST-8P) with P) becomes, for example, 1°C or more, the operation of the compressor (1) is started, and the opening control flow (1) of the hot gas valve (10), which will be explained next, is started. ).

In addition, when controlling the opening degree of the hot gas valve (10) to 100% instead of stopping the compressor (1),
If the temperature difference (ST-SP) becomes 1°C or more, the opening control flow (I) of the hot gas valve (10) is started at this stage.
).

Also, the blowing air temperature (ST) is the set temperature (S P).
Even if it is not the first pull-down and the temperature is 5°C or more, the blow-out air temperature (ST) is set to
When the temperature is 5'C or more, and when the pull-down operation is not performed due to this switching, 30 minutes after the defrost operation is completed.
Even after a minute has passed, the blowing air temperature (ST) remains the set temperature (S
P), or if the blowing air temperature (ST) is 5°C or more relative to the set temperature (S As with the first pulldown, the supply sensor (SS) is switched to the return sensor (R3), and the intake air temperature (RT) detected by the return sensor (RS) is set to the set temperature (SP) by the central processing circuit (CPU). ), the temperature difference (RT) between the intake air temperature (RT) and the set temperature (SP) is calculated.
-5P) becomes, for example, 2°C as described above, a full cooling operation is performed with the opening degree of the hot gas valve (10) set to 0%.

On the other hand, when the blowing air temperature (ST) is lower than 5°C, in other words, when it is not during pulldown, that is, when it is not during the pulldown of each of the above-mentioned aspects such as during the first pulldown, the return sensor (as described above) The hot gas valve (10) is controlled based on the blowing air temperature (ST) detected by the supply sensor (SS) without being switched to the supply sensor (RS), and the control range during descent is
That is, when -1.5°C<5T-8P≦1°C, a predetermined voltage is applied to the electric part (20M) of the hot gas valve (10), and the valve opening is controlled to be proportional to this voltage. The hot gas discharged from the compressor (1) is guided to the evaporator (4) at a flow rate corresponding to the opening degree of the hot gas valve (10), and the temperature of the blown air is control is carried out.

When the temperature difference (ST-SP) becomes less than the lower limit of -1.5°C by controlling the opening degree of the hot gas valve (10), the opening degree of the hot gas valve (10) is adjusted to 100%.
The hot gas valve (10)
Even if the valve opening degree of the compressor (1) is controlled to 1.0%, the temperature of the blown air continues to fall and, for example, when it exceeds -6°C, the compressor (1) is stopped. The temperature difference (ST-
3P) becomes smaller than the lower limit of -1.5°C and falls within the control range, the opening degree of the hot gas valve (10) is controlled.

Further, when the temperature difference (ST-8P) exceeds the upper limit of 2.5°C due to the hot gas bypass by controlling the opening degree of the hot gas valve (10), the opening degree of the hot gas valve (10) is 0%. The system is controlled to perform full cooling operation.

As described above, the blowing air temperature (ST) is adjusted to the set temperature (S P) by controlling the opening degree of the hot gas valve (10). Since the control is switched from the blowout air temperature (ST) to the suction air temperature (RT), in other words, the suction air temperature (RT) and the set temperature (SP)
Based on the temperature difference between Since the opening control of the hot gas valve (10) based on the blowing air temperature (ST) has been discontinued, at the time of pull-down,
This means that the time it takes for the blown air temperature (ST) to stabilize with the set temperature (SP) can be shortened.

In addition, in the embodiment described above, the intake air temperature (
Temperature difference (RT - SP) between RT) and set temperature (SP)
) is 2°C, but this is an example when the outside temperature is 38°C and the set temperature (SP) is 0°C, and this temperature difference (RT-8P) is the set temperature at the first pulldown. (SP
) may be set to a temperature difference that provides stable operation.

(Effect of the invention) The present invention provides a hot gas valve (10) and a condenser (2, 3).
and a hot gas bypass path (8) that bypasses the expansion mechanism (5) to bypass the hot gas to the evaporator (4), and the hot gas bypass path (8) bypasses the expansion mechanism (5) to bypass the hot gas to the evaporator (4).
4) A refrigeration system configured to control the temperature of the air blown from the evaporator (4), comprising a supply sensor (SS) for detecting the temperature of the air blown from the evaporator (4), and an air temperature setting device (21);
A controller having means (22) for comparing the blowing air temperature detected by the supply sensor (S S') with a set temperature, and an output means (23) for outputting an opening/closing signal to the hot gas valve (10) based on the comparison result. (20) and a return sensor (R3) for detecting the temperature of the intake air of the evaporator (4), and switching means capable of switching between the return sensor (RS) and the supply sensor (SS). (25), and an output stop means (24) for stopping the output from the output means (23) during pull-down until the intake air temperature reaches a temperature difference between the set temperature and the temperature for safe operation. Therefore, even if the internal heat capacity is large during the first pulldown, the hot gas valve (10
), it becomes possible to adjust the temperature of the blown air, and as a result, the time required to stabilize the set temperature can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram explaining the present invention in detail, FIG. 2 is a schematic electric circuit diagram, FIG. 3 is a refrigerant piping system diagram of a refrigeration system showing one embodiment of the present invention, and FIG. 4 is a flow chart diagram. FIG. 5 is an explanatory diagram of a control pattern, and FIG. 6 is a schematic refrigerant piping system diagram showing a conventional example. (2, 3)...Condenser (4)...Evaporator (5)...Expansion mechanism (8)...Hot gas bypass path (10)...
... Hot gas valve (20) ... Controller (21) ... Setting device (22) ... Comparison means (23) ... Output, Dynamic stage (24)...Output stop means (SS)...Supply sensor (RS)...
...Return sensor Figure 1 Figure 2 Figure 3 Completed 4

Claims (1)

[Claims] (1) Equipped with a hot gas valve (10) and a hot gas bypass path (8) that bypasses the condenser (2, 3) and expansion mechanism (5) to bypass the hot gas to the evaporator (4). , the evaporator (4) by opening and closing the hot gas valve (10).
A refrigeration system for controlling the temperature of the air blown out,
A supply sensor (SS) for detecting the temperature of the air blown from the evaporator (4), an air temperature setter (21), and means for comparing the temperature of the blown air detected by the supply sensor (SS) with the set temperature ( 22) and output means for outputting an opening/closing signal to the hot gas valve (10) based on the comparison result.
a controller (20) having a controller (23);
A return sensor (RS) is provided to detect the intake air temperature of the evaporator (4), and the return sensor (RS)
The output means (23) is provided with a switching means (25) capable of switching between the supply sensor (SS) and the supply sensor (SS), and at the time of pull-down, the output means (23) A refrigeration system characterized by being provided with output stopping means (24) for stopping output from the refrigeration system.