JPH0776632B2 - Refrigeration system operation controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an operation control device of a refrigerating apparatus, which controls a capacity of a compressor into a plurality of steps according to a refrigerating load, and particularly to a temperature control. Regarding measures to improve followability.

(Prior Art) Conventionally, as disclosed in, for example, Japanese Patent Laid-Open No. 59-185931, in an air conditioner equipped with a compressor that can be adjusted in a plurality of steps, the difference between the indoor air temperature and the set temperature is set. The temperature is compared for each predetermined set time, and a capacity command signal for increasing or decreasing the capacity of the compressor by one step is output according to the temperature difference value, and the compressor is output according to the value of the capacity command signal. While controlling to increase or decrease or maintain the capacity of
By changing the setting time for outputting the capacity command signal only when the device is started up, it is possible to prevent the overrun due to the excessive capacity and to quickly converge the room temperature to the set temperature. What is done is a known technique.

(Problems to be Solved by the Invention) By the way, for example, in a refrigerating apparatus configured to cool a cooling liquid of a chiller circuit by heat exchange with a refrigerant in an evaporator,
When the operating capacity of the compressor is controlled to increase / decrease by one step in every predetermined cycle according to the temperature difference between the coolant temperature and the set temperature as in the above-mentioned conventional one, the cycle has stability and followability. It is set in balance with. That is, if the cycle is too long, the followability deteriorates, and if the cycle is too short, the stability deteriorates, so the values are set to satisfy both.

However, even if the capacity control of the compressor is performed in such a determined cycle, there are the following problems not only at the time of starting the apparatus but also during the subsequent operation. That is, when the load of the chiller circuit changes abruptly and the coolant temperature largely deviates from the set temperature, for example, when the coolant temperature is too high, it takes a long time to approach the set temperature and control performance deteriorates. When the temperature of the cooling liquid is low, in addition to the above problems, there is a risk of freezing of the cooling liquid, so it is necessary to enter antifreeze operation such as forced thermostat off. There is a risk of deterioration.

The present invention has been made in view of such a point, and an object thereof is to provide a means for accelerating the followability without impairing the stability of the control when the temperature of the controlled object deviates greatly from the set temperature. The purpose of the present invention is to promptly respond to a sudden change in load, etc., and thus solve the above problem.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the solution means of the present invention is to shorten the cycle for controlling the increase / decrease of the capacity of the compressor.

Specifically, as shown in FIG. 1 (not including the one-dot chain line portion), the first solution means is a variable capacity compressor (1) that can be adjusted in a plurality of steps, and a heat source side heat exchanger. (2)
And a utilization side heat exchanger (4).

Then, as an operation control device of the refrigeration system, a temperature detection unit (Th) that detects the temperature of the control target, and the control target temperature and the set temperature that are detected by the temperature detection unit (Th) are set at predetermined time intervals. In comparison, a signal output that outputs a load-up signal instructing to increase the capacity of the compressor (1), a load-down signal instructing to decrease the capacity, and a keep signal instructing to maintain the capacity according to the temperature deviation value of both. Means (8) and operation control means (51) that receives the output of the signal output means (8) and controls to increase or decrease the capacity of the compressor (1) step by step are provided.

Further, when a load-up signal is output in a state where the temperature deviation value is equal to or more than a predetermined value on the capacity request side in response to the outputs of the temperature detection means (Th) and the signal output means (8), the signal output means (8) Up-side change means (52) for changing so as to shorten the set time for outputting the command signal
Is provided.

As shown in FIG. 1 (not including the broken line portion), the second solving means is premised on the same refrigerating apparatus as the above-mentioned first solving means. In the state where the operation control means (51) similar to the above means is provided, and further the temperature detection means (Th) and the signal output means (8) receive the output, the temperature deviation value becomes equal to or more than the predetermined value on the capacity non-request side. When the load-down signal is output, the down-side changing means (53) is provided to change the signal output means (8) to shorten the set time for outputting the command signal.

As shown in FIG. 1A (including the broken line portion and the alternate long and short dash line portion), the third solving means is premised on the same refrigerating apparatus as the first solving means, and the first refrigerating apparatus operation control apparatus is The operation control means (51) and the up-side changing means (52) similar to the solving means of (1) are provided, and further the down-side changing means (53) similar to the second solving means is provided.

The fourth solution means sets the set time in the first, second or third solution means to different values on the side where the capacity of the compressor (1) increases and on the side where the capacity of the compressor (1) decreases.

The fifth solution is, as shown in FIG. 1, the above-mentioned first, second,
In the third or fourth solution means, the compressor (1) has an extremely low load step having a lower capacity than the lowest step in the normal operation region, and in addition, operation of the lowest step in the normal operation region. At the time, when a load down signal is received from the signal output means (8), the operation control means (5
Forced capacity holding means (54) for forcibly stopping the control of 1) to maintain the capacity of the compressor (1) in an extremely low step for a set time, and further after the set time has elapsed, the above signal output When the load down signal is received from the means (8), the compressor (1) is stopped, while when the load up signal or the keep signal is received, the operation control means (51) is controlled to return to the normal operation control. The forced control means (55) is provided.

A sixth solving means is the above-mentioned first, second, third, fourth and fifth solving means, in which the controlled object is a cooling liquid such as a chiller circuit and the utilization side heat exchanger (4) is a refrigerant. The cooling device cools the cooling liquid by heat exchange, and the temperature detecting means (Th) detects the temperature of the cooling liquid at the outlet side of the cooling device (4) of the chiller circuit.

(Operation) With the above configuration, in the invention of claim (1), the signal output means (8) compares the control target temperature detected by the temperature detection means (Th) with the set temperature at predetermined time intervals. Then, a load-up signal, a load-down signal or a keep signal is output according to the temperature deviation between the two, and the operation control means (51) controls the capacity of the compressor (1) to be increased or decreased step by step. .

Here, when the temperature deviation value becomes equal to or larger than the predetermined value on the capacity request side, the up-side changing means (52) is changed to shorten the set time for the signal output means (8) to output the command signal. Control stability is maintained when the temperature to be controlled is near the set temperature, and when the temperature to be controlled deviates greatly from the set temperature, the followability to a sudden increase in load is improved, The convergence time to temperature will be shortened.

According to the invention of claim (2), as with the invention of claim (1), the followability to a sudden decrease in load is improved, the convergence time to the set temperature is shortened, and as a result, compression is achieved. The stop due to the thermo-off of machine (1) is avoided,
The control will be stable.

In the invention of claim (3), the operation of the invention of claim (1) or (2) can be obtained at the same time by the up-side changing means (52) and the down-side changing means (53), and the effect of each invention can be obtained. Combined effects will be obtained.

In the invention of claim (4), since the set times are set to be different on the load-up side and the load-down side, respectively, the sensitivity of the temperature to be controlled that differs between the load-up side and the load-down side is dealt with. The balance between control followability and stability can be maintained at an appropriate value.

In the invention of claim (5), the above claims (1), (2),
In addition to the invention of (3) or (4), operation control means (51)
When the load-down signal is output from the signal output means (8) during the operation in the lowest step of the normal operation area due to, the forced capacity holding means (54) keeps the capacity of the compressor (1) normal during the set time. The compressor (1) is stopped only when the load control signal (55) is maintained at an extremely low step lower than the lowest step in the operating range and the load down signal is still output after the set time has elapsed. As a result, the compressor (1) is prevented from being stopped due to thermo-off as much as possible, and the control is stabilized.

In the invention of claim (6), the above claims (1), (2),
In the invention of (3), (4) or (5), the signal output means (8) causes the compressor (in accordance with the temperature deviation between the coolant temperature at the outlet of the cooler (4) of the chiller circuit and the set temperature ( 1)
Since the operations of the above inventions are performed to control the capacity of the compressor (1), the control is stable even at the outlet temperature of the cooler (4) of the chiller circuit that sensitively follows the capacity control of the compressor (1). A balance between sex and followability will be obtained.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings starting from FIG.

FIG. 2 shows a piping system of a refrigerating apparatus and a chiller circuit according to an embodiment of the present invention, which shows a chiller circuit (30) in which a cooling liquid (water) for a machine or the like circulates and a cooling liquid of the chiller circuit (30). A refrigerating device (31) for cooling is arranged. The refrigeration system (31) includes a compressor (1) whose capacity is adjusted to a plurality of steps by an inverter (6), a condenser (2),
A pressure reducing valve (3) and a cooler (4) that functions as an evaporator and is a use-side heat exchanger that cools the cooling liquid of the chiller circuit (30) that is a control target are provided. 1)
A refrigerant circuit (5) is formed by connecting each of (4) to (4) with a refrigerant pipe.

That is, during operation of the refrigeration system, the refrigerant discharged from the compressor (1) is condensed in the condenser (2), reduced in pressure in the pressure reducing valve (3), and evaporated in the cooler (4), and then the compressor. By circulating so as to return to (1), the cooling liquid in the chiller circuit (30) is cooled by heat exchange with the refrigerant in the cooler (4).

Here, the operating capacity Q of the compressor (1) can be adjusted to 5 steps of 0, 25, 50, 75, 100% of the rated capacity during normal operation, while the operating capacity Q is adjusted only when the apparatus is started. It is made possible to adjust to an extremely low load step with a capacity of 12%, which has a lower capacity than the step.

Further, a thermistor (Th) (a detection part of a water temperature control thermostat) as a temperature detecting means for detecting the outlet temperature of the cooling liquid is arranged in the outlet side water pipe of the cooler (4), and the thermistor ( The output of Th) is connected to a temperature controller (8) which is a controller of a water temperature control thermostat. That is, based on the magnitude of the cooling water cooler (4) outlet temperature detected by the thermistor (Th) and its set temperature, the temperature controller (8) increases or decreases the total capacity of the compressor (1). The temperature controller (8) has a function as a signal output means. The signal of the temperature controller (8) can be input to the controller (9) that controls the operation of the entire apparatus.

Here, the temperature controller (8) is not shown three output terminals (Y ₁₎ ~ (Y ₃₎ is arranged. As shown in FIGS. 3 (a) and 3 (b), the output terminals (Y ₁ ) and (Y ₂ ) have a predetermined differential ΔT (for example, a temperature difference of about 2 ° C.) with respect to a change in water temperature. Have two first
Based on the first and second set temperatures Ts1 and Ts2 (where Ts1 <Ts2, values of about 7 ° C. and 5 ° C., respectively), the set temperatures Ts
1 and Ts2 are specified individual differentials (eg 0.4 ° C)
It outputs two outputs 1 and 2 for switching on / off with dT1 and dT2. That is, output 1
Changes from ON to OFF when the set temperature Ts1 is reached when the water temperature rises, while the temperature (Ts1-dT
1) is switched from OFF to ON, and output 2 switches from ON to OFF when the set temperature Ts2 is reached when the water temperature is decreasing, and is switched from OFF to ON when the temperature (Ts1 + dT2) is reached when the water temperature is rising. It is designed to be replaced.

Then, according to the combination of the outputs 1 and 2 of the terminals (Y ₁ ) and (Y ₂ ), the temperature controller (8) to the controller (9)
In contrast, compressors (1a), (1b) as shown in Table 1 below
A command signal for capacity control is output. That is,
If output 1 is on and output 2 is off, output 1 and output 2 are both load-down signals that instruct to reduce the total capacity of compressors (1a) and (1b) because the water temperature is low. If it is on, the keep signal that commands to maintain the current total capacity because the water temperature is in the set region is issued. If the output 1 is off and the output 2 is on, the command is to increase the total capacity because the water temperature is high. Output a load-up signal.

However, in Table 1 above, when both outputs 1 and 2 are off, it means that the water piping is frozen, and at that time, so-called freeze protection operation for freeze protection is performed.

On the other hand, as shown in FIG. 3C, the output terminal (Y ₃ ) has a predetermined temperature range B (for example, a temperature range B above the first set temperature Ts1).
Output value 3 that switches the output value between the upper limit value Tu of the capacity requesting side that is higher by about 2.3 ° C) and the lower limit value Tl of the capacity non-requesting side that is lower than the second set value Ts2 by the predetermined width B. It is done like this. That is, it is off near the set temperature, and when the water temperature rises into the high temperature region and reaches the upper limit value Tu, it turns on and issues an upper limit signal, while the water temperature falls from that state and the temperature is lower than the upper limit value Tu. Low differential (Tu-dT ₃ ) by dT ₃ (for example, a value around 0.3 ° C)
When it reaches, the switch is turned off and the upper limit signal is released. Further, in the low temperature region of the water temperature, when the water temperature falls and reaches the lower limit value Tl, it is turned on and issues a lower limit signal, while the water temperature rises from that state and a predetermined differential dT ₄ (e.g. When it reaches a value (Tl + dT ₄ ) higher by about 0.3 ° C), it is turned off and the lower limit signal is released.

The controller (9) controls the operating capacity of the compressor (1) according to the command signal from the temperature controller (8). Hereinafter, the control content will be described based on the flowcharts in FIGS. 4A and 4B. Figure 4A shows
Show the main flow, after initialization in step S ₁ ,
In step S ₂ , it is determined whether or not the load down signal is output, and if not output, the process proceeds to step S ₃ to perform the following control.

That is, in step S ₃ , the compressor (1) is held at an extremely low load step for 12% for a certain period of time, and then the start-up operation for maintaining the capacity of the compressor (1) at the lowest step of normal operation is performed. In step S ₄ , the total capacity Q = 1 is stored. Then, in step S ₅ , it is determined whether or not there is an upper limit signal, and if the upper limit signal is not output, the process proceeds to step S ₆ and the first setting which is the set time of the first timer (not shown). While the time t ₁ is set to the standard value A ₁ on the up side (for example, a time of about 180 seconds), if the upper limit signal is output, the set time t ₁ of the first timer is set to the above standard in step S ₇ . was set to half the value a _1/2 value of a ₁ (for example, about 90 seconds), respectively proceeds to step S _8.

Then, in step S ₈ , the count T ₁ of the first timer (not shown) is started, and in step S ₉ , wait until the count T ₁ becomes the first set time t ₁ or more, during which step
If the load down signal is input in the determination of S _10, the process proceeds to step S ₂₄ described below, and if the load down signal is not input, after clearing the timer count in step S ₁₁ ,
Load up signal in step S ₁₂ it is determined whether it is output.

Here, in the determination of step S _12, to be output load up signal, that is, if the keep-signals, while maintaining the capacity of the compressor (1) repeating the above control steps S ₅ to S _11, When the load-up signal is output,
It proceeds to step S _13, to determine whether the 4 (step) or total capacity Q is 100%, if 4 (step),
Returns to step S ₅ can not have increased capacity, the total capacity Q is not the 4 (step), as Q = Q + 1 proceeds to step S _15, the total capacity Q is one step increased change. Then, in step S _15, performs capacity increase control for increasing by one step the capacity of each compressor (1) according to the value of the total capacity Q was changed in the above.

On the other hand, in the judgment at the step S _2, when the load down signal is output, the process proceeds to step S _16, it is determined whether or not the lower limit signal is output, the step S if there is a lower limit signal _{At 17} , the second set time t ₂ which is the set time of the second timer is set to a predetermined standard value A ₂ (for example, about 45 seconds), and if there is a lower limit signal, at step S ₁₈ , the second set time t _{2 is} set.
Was set to half A _2/2 above the standard value A ₂ (e.g., about 22 seconds), respectively proceeds to step S _19.

Then, in step S ₁₉ , the count T ₂ of the second timer (not shown) is started, and in step S ₂₀ , wait until the count T ₂ reaches the second set time t ₂ , during which the determination in step S ₂₁ is made. When the load-up signal is inputted proceeds to step S _5, to be entered is loaded up signal, the step S
After resetting the count T ₂ to “0” at ₂₂ , step S ₂₃
Then, it is determined whether the total capacity Q is 0 step.

Then, it is impossible down the capacity if the total capacity Q is determined at the step S ₂₃ is 0 (step), the step
While repeating the control in the step S ₁₉ to S ₂₂ returns to S _19,
If the total capacity Q is not 0 (step), the total capacity Q is reduced by one step to Q = Q−1 in step S ₂₄ , and in step S ₂₅ , the changed total capacity Q is 1 to 4
Determine which one of the (step), 0 (step) Otherwise, i.e. unless the stop command of the compressor (1) have been made, the inverter corresponding to the command in step S ₂₆ (6) While the frequency of the compressor is adjusted to control the capacity of the compressor (1), the changed capacity of the compressor (1) is 0.
If it is (step), forced operation shown in the flowchart of FIG. 4B is performed in step S ₁₇ .

That is, in step R ₁ , the compressor (1) is operated at an extremely low load step of 12% capacity, and at the same time, set time t ₃
(For example, about 45 seconds) 3 starts counting T ₃ of timer having a first timer count T ₃ in step R ₂
There wait until the set time t ₃ above, when the set time elapses t _3, whether the count T ₃ of the third timer is cleared proceeds to step R _3, in step R _4, still there is a load down command Determine whether.

Here, still goes to step R _5, if the load down command, while stopping the compressor (1), if there is no load down command, that is, if the output load up signal or keep signal, Go to step R ₆
At the same time as performing the% capacity operation, a count of a fourth timer (not shown) having a set time t ₄ (for example, a time of about 45 seconds)
Start T ₄ , wait until the count T ₄ of the second timer reaches the set time t ₄ or more in step R ₇ , and when the set time t ₄ has elapsed, clear the count T ₄ of the 4th timer in step R ₈ . After that, in step R ₉ , it is determined whether or not the load-down signal is further output.

Then, if the output load down signal, while stopping the compressor (1) and proceeds to step R _5, if it is not output load down the signal and returns to normal operation.

In the above flow, the control of step S ₈ to S ₁₅ and S ₁₉ to S _26, receiving the output of said signal output means (8) performs control such that the increase or decrease or maintain one step the capacity of the compressor (1) The operation control means (51) is configured. Then, the control in step S ₅ to S _7, when the load-up signal in a state where a temperature deviation value exceeds a predetermined value of the capacity requester is output, the signal output means (8) outputs a load up signal The up-side changing means (52) for changing the first set time t ₁ to be shorter is configured, and steps S _{16 to} S _{18 are performed.}
As a result, when the load down signal is output in a state where the temperature deviation value is equal to or greater than the predetermined value on the capacity non-request side, the second set time t _{2 at} which the signal output means (8) outputs the load down signal is shortened. Down side change means to change so that (53)
Is configured.

Further, according to the invention of claim (4), when the load down signal is received from the signal output means (8) during the operation of the lowest step in the normal operation region by the control of steps R ₁ and R ₂ , the operation control means is A forced capacity holding means (54) for forcibly stopping the control of (51) and maintaining the capacity of the compressor (1) in an extremely low step for a set time is configured, and steps R ₄ to R ₅ or R are performed. By controlling to ₇ , the compressor (1) is stopped when a load down signal is received from the signal output means (8) after the set time has passed, while the operation control means is received when a load up signal or a keep signal is received. A compulsory control means (55) for controlling the normal operation control by (51) is restored.

Therefore, according to the invention of claim (1), the temperature controller (signal output means) (8) compares the control target temperature detected by the temperature detection means (Th) with the set temperature at every predetermined set time. A load-up signal, a load-down signal, or a keep signal is output according to the temperature deviation between the two, and the operation control means (51) controls the capacity of the compressor (1) to be increased or decreased step by step.

Here, when the temperature deviation value becomes equal to or larger than a predetermined value on the capacity request side, that is, when it becomes equal to or larger than the upper limit value Tu of the embodiment, the up side changing means (52) causes the signal output means (8). Is changed to shorten the set time for outputting the command signal (the first set time t ₁ in the above embodiment). That is, like the above-mentioned conventional one, in which the capacity is controlled at every constant set time regardless of the value of the temperature deviation value, the controlled object is, for example, the outlet water temperature of the chiller circuit (30) as in the above embodiment. If the outlet water temperature is compressor (1)
It is possible to avoid control instability in which the outlet water temperature greatly changes above and below the set temperature even if it is sensitively changed with respect to the control result of the capacity, that is, the capacity. However, on the other hand, when the water temperature rises higher than the set temperature, it takes time to pull down from that value to the set temperature, and there is a possibility that good water temperature control cannot be performed.

On the other hand, in the present invention, when the load rapidly increases and the outlet water temperature exceeds the upper limit Tu, the set time for outputting the command signal of the signal output means (8) by the up side change means (52). Since the (first set time t ₁ ) is changed to be shorter and the interval for adjusting the capacity of the compressor (1) by the operation control means (51) is shortened, stability of control is improved when the water temperature is near the set temperature. When the water temperature greatly deviates from the set temperature while maintaining it, it is possible to improve followability to a sudden change in the load, and particularly to shorten the pull-down time to the set temperature. .

In the invention of claim (2), as in the case of the invention of claim (1), when the outlet water temperature falls below the lower limit value due to a decrease in load, the down side changing means (53) causes a signal to be output. The set time (second time) when the output means (8) outputs the command signal
Since the set time t ₂ ) is changed to be shorter, the followability to a sudden change in the load is improved, so that the outlet water temperature can be promptly recovered. Also, because of that,
It is possible to avoid the start of the antifreezing operation, that is, the stop due to the thermo-off of the compressor (1) as much as possible. Particularly, in the case of controlling the outlet water temperature as in the above embodiment, the compressor (1)
Since the result of the capacity control of the compressor appears sensitively as a change in the water temperature, if the thermostat of the compressor (1) is frequently stopped,
While the water temperature may change significantly during that time, the control of the water temperature may become unstable. By avoiding such a thermo-off stop of the compressor (1), it is possible to stabilize the control. .

In the invention of claim (3), the operation of the invention of claim (1) or (2) can be obtained at the same time by the up-side changing means (52) and the down-side changing means (53), and the effect of each invention can be obtained. Combined effects will be obtained.

In the invention of claim (4), the set time (first set time) t ₁ for outputting the command signal of the signal output means (8) on the load-up side is the set time on the load-down side as in the above embodiment. (Second setting time) It is set to a value larger than t ₂ . That is, the set times are set to be different on the load-up side and the load-down side. That is, in general, the change in the temperature to be controlled with respect to the result of the capacity control of the compressor (1) differs between the load-up and the load-down, so the control followability and stability should always be maintained at good values. However, according to the present invention, it is possible to maintain a suitable balance between control followability and stability in accordance with such different sensitivities of control target temperatures.

In the invention of claim (5), the above claims (1), (2),
In addition to the invention of (3) or (4), operation control means (51)
When the load-down signal is output from the signal output means (8) during the operation in the lowest step of the normal operation area due to, the forced capacity holding means (54) keeps the capacity of the compressor (1) normal during the set time. The compressor (1) is stopped only when the load control signal (55) is maintained at an extremely low step lower than the lowest step in the operating range and the load down signal is still output after the set time has elapsed. Therefore, the thermo-off stop of the compressor (1) is avoided as much as possible. Therefore, in each of the above inventions, it is possible to further stabilize the control.

In the invention of claim (6), the above claims (1), (2),
In the invention of (3), (4) or (5), the signal output means (8) causes the temperature difference between the coolant temperature at the outlet of the cooler (4) of the chiller circuit (30) and the set temperature to be changed, A command signal for increasing or decreasing the capacity of the compressor (1) is output, and the operation control means (51) controls the capacity of the compressor (1) to increase or decrease step by step. Here, since the outlet temperature of the cooler (4) of the chiller circuit (30) sensitively follows the capacity control of the compressor (1), the sampling time for capacity control is ensured in order to ensure control stability. That is, in the above embodiment, it is necessary to set the set times t ₁ and t ₂ to a certain extent. Therefore, if the water temperature greatly deviates from the set temperature due to a sudden change in load, etc., the capacity of the compressor (1) may be changed step by step by sampling every standard set time. However, even in such a case, according to the above inventions,
It is possible to ensure controllability.

Although the compressor (1) is capacity-controlled by the inverter (6) in the above embodiment, the present invention is
The present invention is not limited to this embodiment, and may be a combination of two compressors whose capacity is adjusted to full load and unload by an unloader mechanism. However, the invention of claim (5) is limited to those having an extremely low load step in addition to the step of normal operation, such as a screw compressor and a turbo compressor, in addition to the inverter.

(Effect of the Invention) As described above, according to the invention of claim (1), the capacity of the compressor is increased by one step every predetermined set time in accordance with the temperature deviation between the temperature to be controlled and the set temperature. When the temperature deviation is greatly deviated to the capacity request side, the set time for capacity control is changed to a shorter value when the temperature deviation is increased or decreased. In this case, it is possible to improve the followability to a sudden change in the load, and it is possible to shorten the convergence time to the set temperature.

According to the invention of claim (2), when the temperature deviation between the temperature to be controlled and the set temperature greatly deviates to the capacity non-request side,
Since the set time for capacity control is changed to a short time, it is possible to improve the followability to a sudden load change, and to prevent the compressor from turning off as much as possible. The operable area of the machine can be expanded.

According to the invention of claim (3), when the temperature deviation between the temperature to be controlled and the set temperature largely deviates to either the capacity requesting side or the capacity non-requiring side, the capacity of the compressor is adjusted. Since the time is changed, the above claim (1)
The effects of the invention of (2) and (2) can be obtained together.

According to the invention of claim (4), the above-mentioned claim (1),
In the invention of (2) or (3), the set time for adjusting the capacity of the compressor is set to be different on the load-up side and the load-down side. Also, it is possible to maintain a good balance between stability of control and followability.

According to the invention of claim (5), the above-mentioned claim (1),
In addition to the invention of (2), (3), or (4), when a load-down signal is received during operation at the lowest step in the normal operation range, the compressor is not stopped immediately and the normal setting time is set. After maintaining a very low load step lower than the lowest step in the operating range, the compressor is stopped only when there is a load down signal, so it is possible to avoid stopping the compressor due to thermo-off as much as possible. ,
Therefore, the stability of control can be improved.

According to the invention of claim (6), the above-mentioned claim (1),
Since the invention of (2), (3), (4) or (5) is applied to the control of the cooler outlet temperature of the chiller circuit, the cooler outlet that changes sensitively to the capacity change of the compressor. With respect to the temperature as well, the effects of improving control stability and followability according to each of the above inventions can be exhibited.

[Brief description of drawings]

FIG. 1A is a block diagram showing the constitution of the invention of claims (1) to (4), and FIG. 1B is a block diagram showing the constitution of the invention of claim (5). 2 and the following shows an embodiment of the present invention, FIG. 2 is a piping system diagram showing the configurations of a refrigerating device and a chiller circuit, and FIGS. 3 (a) to 3 (c) are water temperatures of three outputs of a temperature controller. Explanatory diagram showing switching characteristics against changes, FIG. 4A and
FIG. 4B shows the control contents of the controller, FIG. 4A is a main flow, and FIG. 4B is a flow chart showing the forced control sub-flow. 1 ...... Compressor 2 ...... Condenser (heat source side heat exchanger) 4 ...... Cooler (use side heat exchanger) 8 ...... Temperature controller (signal output means) 51 ...... Operation control means 52 ...... Up Side change means 53 …… Down side change means 54 …… Forced capacity holding means 55 …… Forced control means Th …… Thermistor (temperature detection means)

Claims (6)

[Claims] 1. A refrigeration system comprising a variable capacity compressor (1) adjustable in a plurality of steps, a heat source side heat exchanger (2) and a utilization side heat exchanger (4) Temperature detecting means (Th) for detecting the temperature of the temperature, the control target temperature and the set temperature detected by the temperature detecting means (Th) are compared at predetermined time intervals, and the above-mentioned temperature deviation values are used in accordance with the temperature deviation values. A signal output means (8) for outputting a load-up signal for instructing to increase the capacity of the compressor (1), a load-down signal for instructing to decrease the capacity, and a keep signal for instructing to maintain the capacity, and the signal output means (8). ) And an operation control means (51) for controlling the capacity of the compressor (1) to be increased or decreased step by step or maintained, and the temperature detection means (Th) and the signal output means (8). Output, the temperature deviation value is required When a load-up signal is output in a state where it exceeds a predetermined value on the demand side, an up-side change means (52) is provided for changing the signal output means (8) so as to shorten the set time for outputting the command signal. An operation control device for a refrigerating apparatus, which is characterized by the above. 2. A refrigeration system comprising a variable capacity compressor (1) adjustable in a plurality of steps, a heat source side heat exchanger (2) and a utilization side heat exchanger (4) Temperature detecting means (Th) for detecting the temperature of the temperature, the control target temperature and the set temperature detected by the temperature detecting means (Th) are compared at predetermined time intervals, and the above-mentioned temperature deviation values are used in accordance with the temperature deviation values. A signal output means (8) for outputting a load-up signal for instructing to increase the capacity of the compressor (1), a load-down signal for instructing to decrease the capacity, and a keep signal for instructing to maintain the capacity, and the signal output means (8). ) And an operation control means (51) for controlling the capacity of the compressor (1) to be increased or decreased step by step or maintained, and the temperature detection means (Th) and the signal output means (8). The temperature deviation value is When the load-down signal is output in a state where the value exceeds the predetermined value on the request side, the signal output means (8) is provided with down-side changing means (53) for changing to shorten the set time for outputting the command signal. An operation control device for a refrigerating apparatus, which is characterized by the above. 3. A refrigeration system comprising a variable capacity compressor (1) adjustable in a plurality of steps, a heat source side heat exchanger (2) and a utilization side heat exchanger (4) Temperature detecting means (Th) for detecting the temperature of the temperature, the control target temperature and the set temperature detected by the temperature detecting means (Th) are compared at predetermined time intervals, and the above-mentioned temperature deviation values are used in accordance with the temperature deviation values. A signal output means (8) for outputting a load-up signal instructing to increase the capacity of the compressor (1), a load-down signal instructing to decrease the capacity, and a keep signal instructing to maintain the capacity, and the signal output means (8). ) And an operation control means (51) for controlling the capacity of the compressor (1) to be increased or decreased step by step or maintained, and the temperature detection means (Th) and the signal output means (8). Output, the temperature deviation value is required When the load-up signal is output in a state where the value exceeds the predetermined value on the demand side, the up-side set time changing means (52) for changing the signal output means (8) to shorten the set time for outputting the command signal. When,
When the load down signal is output in a state where the temperature deviation value is equal to or more than the predetermined value on the capacity non-request side, the down side change is made to shorten the set time for outputting the command signal by the signal output means (8). An operation control device for a refrigeration system, comprising: means (53). 4. The set time is set to different values on the side where the capacity of the compressor (1) increases and on the side where the capacity of the compressor decreases (1), (2) or (3). An operation control device for the refrigeration system described. 5. The compressor (1) has an extremely low load step whose capacity is lower than that of the lowest step in the normal operation region, and the signal output means (8) is used by the signal output means (8) during the operation of the lowest step in the normal operation region. When receiving the load-down signal, the operation control means (51) is forcibly stopped to control the capacity of the compressor (1) in an extremely low step for a set time, and a forced capacity holding means (54). When the load down signal is further received from the signal output means (8) after the set time has elapsed, the compressor (1) is stopped,
A forced control means (55) for controlling the operation control means (51) to return to the normal operation control when receiving a load-up signal or a keep signal. 2), the operation control device for the refrigerating apparatus according to (3) or (4). 6. A control target is a cooling liquid such as a chiller circuit,
The utilization side heat exchanger (4) is a cooler that cools the cooling liquid by exchanging heat with the refrigerant, and the temperature detecting means (Th) detects the temperature of the cooling liquid on the outlet side of the cooling device (4) of the chiller circuit. Claim (1), characterized in that
(2), (3), (4) or the operation control device of the refrigerating apparatus according to (5).