JP5523918B2 - Refrigeration system - Google Patents

Description

  The present invention relates to a refrigeration system in which a secondary refrigerant is cooled or heated by a refrigeration apparatus provided in parallel on the primary side and supplied to a load provided on the secondary side, and in particular, the flow rate on the secondary side is a load. It is suitable for a secondary side variable flow rate system that is variable according to the increase / decrease of.

  A refrigeration system that cools or heats a secondary refrigerant (for example, water, brine, or air) by a plurality of refrigeration units provided in parallel on the primary side and supplies the refrigerant to a load provided on the secondary side, particularly the secondary As a secondary side variable flow rate system in which the flow rate on the side changes in accordance with the increase or decrease of the load, there is one described in Patent Document 1.

  In the refrigeration system described in Patent Literature 1, an upstream header provided on the upstream side of the load and a secondary refrigerant from a plurality of refrigeration apparatuses provided in parallel on the primary side, the downstream side of the load A downstream header for distributing the secondary refrigerant from the load to the plurality of refrigeration devices, and a primary for individually supplying the secondary refrigerant in the downstream header to the refrigeration devices. A side pump, a secondary pump for supplying the secondary refrigerant of the upstream header to the load, and a bypass pipe connecting the upstream header and the downstream header. In addition, it is described that the number of operating refrigeration units is determined based on the temperature difference between the inlet and outlet of the secondary refrigerant on the load side, the flow rate to the load device, and the amount of load heat.

JP 2003-294290 A

  Since the secondary pump is increased or decreased according to the inlet / outlet temperature difference of the secondary refrigerant flowing through the load, the flow rate of the secondary pump increases to increase the amount of heat required when the load increases. Try to secure. For this reason, although the flow volume which flows through the said bypass piping increases, since the return temperature from load does not rise immediately, the raise of refrigeration apparatus entrance side water temperature is delayed. Therefore, the secondary refrigerant flow rate on the primary side and the capacity of the refrigeration apparatus do not increase easily. For this reason, the flow volume which flows through the said bypass piping increases, The work amount of the secondary side pump correspondingly increases, and the subject that the efficiency reduction of the whole system was caused occurred. Also, when the load is reduced, the flow rate of the secondary pump decreases, so the excess flow from the refrigeration system flows through the bypass pipe and is pumped again by the primary pump, so the primary pump consumes extra power. However, this also causes a decrease in the efficiency of the entire system.

  An object of the present invention is to obtain a refrigeration system that can save energy by reducing the flow rate through the bypass pipe.

  In order to achieve the above object, the present invention provides an upstream header provided on the upstream side of a load and a downstream header from a plurality of refrigeration units provided in parallel on the primary side, and downstream of the load. A downstream header for distributing the secondary refrigerant from a load to the plurality of refrigeration devices, and a 1 for individually supplying the secondary refrigerant in the downstream header to the refrigeration devices In the refrigeration system comprising a secondary pump, a secondary pump for supplying the secondary refrigerant of the upstream header to the load, and a bypass pipe connecting the upstream header and the downstream header, Flow rate detection means for detecting the flow rate of the secondary refrigerant flowing through each refrigeration apparatus, inlet side temperature detection means for detecting the temperature of the secondary refrigerant flowing into each refrigeration apparatus, and each refrigeration apparatus Said spilled from Outlet side temperature detection means for detecting the temperature of the secondary refrigerant, load upstream temperature detection means for detecting the temperature of the secondary refrigerant between the upstream header and the load, and load upstream temperature detection When the temperature detected by the means is higher than the temperature detected by the outlet-side temperature detection means in the operating refrigeration apparatus among the plurality of refrigeration apparatuses, the entire secondary refrigerant flowing through the primary side When the temperature detected by the inlet side temperature detection means in the refrigeration apparatus in operation among the plurality of refrigeration apparatuses is lower than a predetermined temperature, the first flow is performed. And a control means for controlling the overall flow rate of the secondary refrigerant to decrease.

  Another feature of the present invention is that an upstream header provided on the upstream side of the load and a secondary refrigerant from a plurality of refrigeration units provided in parallel on the primary side, and provided on the downstream side of the load A downstream header for distributing the secondary refrigerant from the load to the plurality of refrigeration devices, and a primary pump for individually supplying the secondary refrigerant of the downstream header to the refrigeration devices, In a refrigeration system including a secondary pump for supplying the secondary refrigerant of the upstream header to the load, and a bypass pipe connecting the upstream header and the downstream header, the refrigerant flows through the refrigeration devices 2 A flow rate detecting means for detecting the flow rate of the secondary refrigerant, an inlet side temperature detecting means for detecting the temperature of the secondary refrigerant flowing into each refrigeration apparatus, and the temperature of the secondary refrigerant flowing out from each refrigeration apparatus Outlet side temperature to detect Detecting means; load upstream temperature detecting means for detecting a temperature of the secondary refrigerant between the upstream header and the load; temperatures detected by the load upstream temperature detecting means; and the plurality of refrigeration units The temperature detected by the outlet side temperature detecting means in the operating refrigeration apparatus of the apparatus is compared, and the temperature detected by the inlet side temperature detecting means in the operating refrigeration apparatus of the plurality of refrigeration apparatuses is compared. The flow rate of the secondary refrigerant flowing through the primary side is controlled such that the flow rate of the secondary refrigerant flowing through the bypass pipe decreases. And a control means.

  According to the present invention, since the flow rate flowing through the bypass pipe can be reduced, an effect that energy saving of the refrigeration system can be achieved is obtained.

The systematic diagram which shows Example 1 of the refrigeration system of this invention. The flowchart which shows the control flow in Example 1 of this invention.

First, the basic configuration of the embodiment of the present invention will be described.
In this embodiment, secondary refrigerant from a plurality of refrigeration units provided in parallel on the primary side flows in, and an upstream header provided on the upstream side of the load, and a load provided on the downstream side of the load. A downstream header for distributing the secondary refrigerant of the plurality of refrigeration devices, a primary pump for individually supplying the secondary refrigerant of the downstream header to the refrigeration devices, The secondary variable flow rate system includes a secondary pump for supplying the secondary refrigerant of the upstream header to the load, and a bypass pipe connecting the upstream header and the downstream header. Yes.

  The refrigeration apparatus includes a compressor capable of continuously changing an operating capacity, and includes a heat exchanger that cools or heats a secondary refrigerant (such as water) by a refrigerant (primary refrigerant) discharged from the compressor. Have. An inlet side temperature detecting means (inlet temperature detecting thermistor) for detecting the inlet temperature of the secondary refrigerant is provided on the inlet side of the heat exchanger, and an outlet side temperature detecting means for detecting the outlet temperature on the outlet side ( An outlet temperature detection thermistor) is provided. Moreover, the primary side pump for supplying the said secondary refrigerant | coolant to each refrigeration apparatus is provided for every refrigeration apparatus, and this primary side pump becomes a structure which can change a flow volume continuously. .

  In the upstream header, the secondary refrigerant flowing in from the plurality of refrigeration units and the secondary refrigerant flowing in from the bypass pipe merge and are then supplied to the load via the secondary pump. The upstream header is provided with a load upstream temperature detection means (a post-merging temperature detection thermistor) for detecting the temperature of the secondary refrigerant after merging. Furthermore, it has a flow rate detection means for detecting the flow rate (primary side flow rate) of the secondary refrigerant flowing through each of the plurality of refrigeration apparatuses.

  The capacity of the compressor of the refrigeration apparatus is controlled so that the outlet temperature of the heat exchanger is constant. In addition, the temperature detected by the load upstream side temperature detecting means and the temperature detected by the outlet side temperature detecting means in the operating refrigeration apparatus among the plurality of refrigeration apparatuses are compared, and the plurality of units The temperature of the secondary refrigerant flowing through the bypass pipe is reduced by comparing the temperature detected by the inlet-side temperature detection means in the refrigeration apparatus in operation among the refrigeration apparatuses with a predetermined temperature. Thus, a control means (controller) for controlling the flow rate of the secondary refrigerant flowing on the primary side is provided.

  For example, in the case of an operation for cooling a load, the control means is configured such that the temperature detected by the load upstream temperature detection means is the outlet side temperature detection means in the operating refrigeration apparatus among the plurality of refrigeration apparatuses. When the temperature is higher than the temperature detected in the above, the flow rate of the entire secondary refrigerant flowing on the primary side is controlled to increase, and the inlet side temperature in the operating refrigeration apparatus among the plurality of refrigeration apparatuses. When the temperature detected by the detection means is lower than the predetermined temperature, control is performed so that the flow rate of the entire secondary refrigerant flowing through the primary side is reduced.

  Further, in the case of an operation for heating the load, the control means performs an operation opposite to that for cooling the load. That is, when the temperature detected by the load upstream side temperature detecting means is lower than the temperature detected by the outlet side temperature detecting means in the operating refrigeration apparatus of the plurality of refrigeration apparatuses, the bypass Since the flow from the downstream header to the upstream header is generated through the pipe, the flow rate of the entire secondary refrigerant flowing through the primary side is controlled so as to increase and during the operation of the plurality of refrigeration apparatuses. When the temperature detected by the inlet side temperature detecting means in the refrigeration apparatus is higher than a predetermined temperature, a flow from the upstream header to the downstream header occurs through the bypass pipe, and therefore flows through the primary side. Control is performed so that the flow rate of the entire secondary refrigerant decreases.

By controlling as described above, the flow rate of the secondary refrigerant flowing through the bypass pipe can be reduced, so that the power of the primary side pump and the secondary side pump can be reduced and energy saving of the refrigeration system can be achieved. Can be achieved.
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a system diagram of a refrigeration system showing Embodiment 1 of the present invention. In this embodiment, the secondary refrigerant is water, and it will be described as a refrigeration system as water cooling equipment that cools the water with a refrigeration apparatus and supplies the water to a load.

  In FIG. 1, A is the primary side and B is the secondary side. On the primary side A, a plurality of (in this example, four) refrigeration apparatuses 1a to 1d are provided in parallel, and each of the refrigeration apparatuses continuously controls the rotation speed and pumps the secondary refrigerant. Side pumps 5a to 5d are also provided, and the flow rate of the secondary refrigerant flowing through the refrigeration apparatuses 1a to 1d is controlled by changing the rotational speed of the primary side pumps 5a to 5d.

  The secondary side B is provided with a load 20 cooled by the secondary refrigerant, an upstream header 7 provided on the upstream side of the load 20, and a downstream header 8 provided on the downstream side of the load 20. The secondary refrigerant from the upstream header 7 is pumped by a plurality of secondary pumps 6 a to 6 d and supplied to the load 20 via the intermediate header 9 to cool the load 20. The secondary refrigerant after cooling the load 20 is sent to the downstream header 8. The flow rate of the secondary refrigerant flowing through the secondary side B is controlled by controlling the number of the plurality of secondary pumps 6a to 6d or by controlling the rotational speed of at least one secondary pump. Reference numeral 13 denotes a load inlet temperature detector (thermistor) that detects the inlet temperature of the secondary refrigerant to the load 20, and reference numeral 14 denotes a load outlet temperature detector (thermistor) that detects the outlet temperature of the secondary refrigerant output from the load 20. The secondary pumps 6a to 6d are controlled in accordance with the temperature difference of the secondary refrigerant detected by the temperature detectors 13 and 14, and if the temperature difference is larger than a set value (predetermined temperature difference), the load 20 The flow rate of the secondary refrigerant supplied to the load 20 is increased, and if the temperature difference is smaller than the set value, the flow rate of the secondary refrigerant supplied to the load 20 is decreased so that the temperature difference approaches the set value. Be controlled.

  In addition, 15 is a flow control valve, 16 is a relief valve for letting a pressure escape to the downstream header 7 when the pressure of the intermediate header 9 rises. Control of the secondary side B secondary pumps 6a to 6d and the flow rate control valve 15 is controlled by a secondary controller (not shown) provided on the secondary side.

  The secondary refrigerant in the downstream header 8 is pumped to the refrigeration apparatuses 1a to 1d via the primary pumps 5a to 5d. Each of the refrigeration apparatuses 1a to 1d is provided with a compressor (not shown) for compressing the primary refrigerant, and the compressor has a configuration capable of continuously controlling the operation capacity. In addition, heat exchangers 2a to 2d for exchanging heat between the primary refrigerant and the secondary refrigerant, inlet side temperature detection means for detecting the inlet side temperature of the secondary refrigerant to the heat exchanger (thermistor for detecting the inlet temperature) ) 3a to 3d, outlet side temperature detecting means (outlet temperature detecting thermistors) 4a to 4d for detecting the outlet side temperature of the heat exchanger are provided. In the refrigeration apparatuses 1a to 1d, the capacity (for example, the rotation speed) of the compressor is controlled so that the temperatures detected by the outlet side temperature detecting means 4a to 4d become a predetermined constant temperature. In this embodiment, in order to detect the flow rate of the secondary refrigerant flowing through each of the refrigeration apparatuses 1a to 1d, the flow rate detection means for calculating the flow rate based on the rotation speed of the primary pumps 5a to 5d is provided. . The flow rate detection means may be configured to directly measure the amount of the secondary refrigerant flowing through the pipe flowing into and out of each refrigeration apparatus with a flow meter.

  11 is a bypass pipe connecting the upstream header 7 and the downstream header 8, and when the flow rate of the secondary refrigerant flowing through the secondary side B is larger than the flow rate of the secondary refrigerant flowing through the primary side A, A part of the secondary refrigerant flows from the downstream header 8 to the upstream header 7 side via the bypass pipe 11, and conversely, the flow rate of the secondary refrigerant flowing through the primary side A flows through the secondary side B. When the flow rate is higher than the refrigerant flow rate, a part of the secondary refrigerant in the upstream header 7 flows to the downstream header 8 via the bypass pipe 11. Reference numeral 10 denotes a load upstream temperature detection means (a junction temperature detection thermistor) that detects the temperature of the secondary refrigerant in the upstream header 7. The load upstream temperature detection means 10 flows in from the refrigeration apparatuses 1 a to 1 d. The temperature at which the secondary refrigerant flowing through and the secondary refrigerant flowing in via the bypass pipe 11 merge and are mixed is detected. Since the value detected by the load upstream temperature detecting means 10 is substantially the same as the temperature detected by the load inlet temperature detector 13, the load inlet temperature detector 13 can be substituted. The temperature detected by the load upstream side temperature detection means 10 is the operating refrigeration apparatus among the plurality of refrigeration apparatuses 1a to 1d when there is no secondary refrigerant flowing into the upstream header 8 from the bypass pipe 11. It becomes the same as the average value of the temperature detected by the said outlet side temperature detection means 4a-4d. That is, in this embodiment, since the flow rates of the primary side pumps 5a to 5d of the operating refrigeration apparatus are controlled to be the same, they are detected by the outlet side temperature detecting means 4a to 4d of the operating refrigeration apparatus. The average value of the obtained temperatures becomes equal to the temperature at which the secondary refrigerant flowing out of the refrigeration apparatus in operation is mixed.

  When there is a secondary refrigerant flowing into the upstream header 7 from the bypass pipe 11, the temperature detected by the load upstream temperature detection means 10 is the operating temperature of the plurality of refrigeration apparatuses 1 a to 1 d. It becomes higher than the average value of the temperatures detected by the outlet side temperature detecting means 4a to 4d in the refrigeration apparatus. The reason is that the secondary refrigerant having a high temperature is mixed in the upstream header 7 from the downstream header 8 through the bypass pipe 11 without being cooled by the refrigeration apparatus.

  On the other hand, when there is no secondary refrigerant flowing from the upstream header 7 to the downstream header 8 through the bypass pipe 11, the temperatures detected by the inlet side temperature detecting means 3a to 3d of the refrigeration apparatuses 1a to 1d are the load. It becomes substantially equal to the temperature detected by the outlet temperature detector 14. Since the temperature on the load outlet side is controlled to be a predetermined temperature (set temperature), the temperatures detected by the inlet side temperature detecting means 3a to 3d are substantially equal to the predetermined temperature (set temperature).

  When there is a secondary refrigerant flowing into the downstream header 8 from the bypass pipe 11, the temperature detected by the inlet side temperature detecting means 3 a to 3 d is the temperature detected by the load outlet temperature detector 14 or the predetermined value. It becomes lower than the temperature (set temperature). The reason is that a part of the low-temperature secondary refrigerant cooled by the refrigeration apparatus flows into the downstream header 8 from the upstream header 7 via the bypass pipe 11 and is heated by the load 20. This is because it is mixed with the refrigerant.

  Therefore, the temperature detected by the load upstream side temperature detecting means 10 is compared with the temperature detected by the outlet side temperature detecting means 4a to 4d in the operating refrigeration apparatus among the plurality of refrigeration apparatuses. The temperature detected by the inlet side temperature detecting means 3a to 3d in the operating refrigeration apparatus among the plurality of refrigeration apparatuses and a predetermined temperature (or detected by the load outlet temperature detector 14). If the secondary refrigerant is flowing through the bypass pipe 11, it can be determined in which direction the secondary refrigerant is flowing. In this embodiment, a controller 12 (control means) is provided for controlling the flow rate of the secondary refrigerant flowing on the primary side so that the flow rate of the secondary refrigerant flowing in the bypass pipe 11 is reduced or eliminated.

  Next, an example of control by the controller 12 will be described with reference to the flowchart shown in FIG. The controller 12 shown in FIG. 1 is based on detected values from the load upstream side temperature detecting means 10, the outlet side temperature detecting means 4a to 4d of the refrigeration apparatuses 1a to 1d, the inlet side temperature detecting means 3a to 3d, and the flow rate detecting means. The refrigerating apparatuses 1a to 1d and the primary pumps 5a to 5d provided on the primary side A are controlled. The secondary pumps 6a to 6d and the flow rate control valve 15 provided on the secondary side B are controlled by a secondary controller (not shown) as described above.

  In FIG. 2, in step 101, the refrigeration apparatus to be activated first is set, the inlet temperature Ta and the outlet temperature Tb to the refrigeration apparatus are set, and the maximum flow rate Umax and the minimum flow rate of the primary pumps 5a to 5d. Umin is also set.

Next, in step 102, the controller 12 detects the inlet water temperatures Ti _{1 to} Ti ₄ from the inlet side temperature detection means 3a to 3d of the refrigeration apparatuses 1a to 1d to the refrigeration apparatuses. Further, to detect the outlet water temperature _To 1 _{~To 4} from the refrigeration system from the outlet side temperature detection means 4 a to 4 d. Further, the secondary refrigerant water temperature (merging portion water temperature) Tj in the upstream header is detected from the load upstream temperature detection means 10. Further, the flow rate U of the secondary refrigerant flowing through the refrigeration apparatuses 1a to 1d is calculated and detected from the rotation speed of the primary pumps 5a to 5d.

In step 103, the controller 12 calculates the average temperature To of the outlet water temperatures To _{1 to} To ₄ in the operating refrigeration apparatus, and compares this average temperature To with the secondary refrigerant water temperature Tj in the upstream header. If the condition of “Tj> To” is satisfied, the routine proceeds to step 104 where the flow rate U of the secondary refrigerant flowing on the current primary side and the maximum flow rate Umax of the primary pumps 5a to 5d in operation are Compare

  If the condition of “U = Umax” is satisfied, the flow rate of the entire secondary refrigerant flowing on the primary side is increased by increasing the number of operating refrigeration units to be driven (step 105). If the condition of “U = Umax” is not satisfied, control is performed to increase the flow rate of the primary pumps 5a to 5d during operation (step 106).

If the condition of “Tj> To” is not satisfied in step 103, the process proceeds to step 107, and the inlet temperature (set temperature) Ta set in step 101 and the inlet water temperature Ti ( may be an average value of Ti ₁ ~Ti _4, compare also good) and either of the inlet water temperature Ti 1 ~Ti _4, to satisfy the condition "Ta>Ti", flows a refrigeration apparatus in operation The flow rate U of the secondary refrigerant is compared with the minimum flow rate Umin of the operating primary pumps 5a to 5d (step 108). If the condition of “U = Umin” is satisfied, the flow rate of the secondary refrigerant flowing through the entire primary side is decreased by reducing the number of operating units (step 109). When the condition of “U = Umin” is not satisfied, control is performed so as to decrease the flow rate of the primary pumps 5a to 5d during operation (step 110).

  In step 107, if the condition of “Ta> Ti” is not satisfied, the flow rate of the primary pumps 5a to 5d remains as it is because the secondary refrigerant is not flowing through the bypass pipe 11 or is very small. Maintain (step 111).

Turning now to step 112, after a lapse of effective latency, proceeds to the step 102 again, as before, inlet water temperature Ti1～Ti4, outlet water temperature _To 1 _{~To 4,} 2-order refrigerant in the upstream side header The water temperature Tj and the flow rate U of the secondary refrigerant flowing through each of the refrigeration apparatuses 1a to 1d are detected, and thereafter, the same operation as described above is repeated.

  In addition, in FIG. 1, although the said controller (control means) 12 demonstrated in the example installed in the exterior of freezing apparatus 1a-1d, the control board for controlling each freezing apparatus is provided in freezing apparatus 1a-1d. Therefore, if a control function similar to that of the controller 12 shown in FIG. 1 is incorporated in the control board of any of the refrigeration apparatuses 1a to 1d, the external attachment shown in FIG. The controller 12 is not necessary, and the function as the control means can be incorporated into the control board provided in the refrigeration apparatus, so that it can be manufactured at low cost.

  According to the present embodiment, based on the detected values from the load upstream side temperature detection means 10, the outlet side temperature detection means 4a to 4d of the refrigeration apparatuses 1a to 1d, the inlet side temperature detection means 3a to 3d, and the flow rate detection means. Since the refrigeration apparatuses 1a to 1d and the primary pumps 5a to 5d provided on the primary side A are controlled by the control flow as shown in FIG. 2, the secondary refrigerant on the secondary side B (load side) Since the flow rate of the secondary refrigerant on the primary side A can be quickly adjusted with respect to the fluctuation of the flow rate, the flow rate of the secondary refrigerant flowing through the bypass pipe 11 can be eliminated in a short time. Therefore, since the primary pumps 5a to 5d and the secondary pumps 6a to 6d do not consume extra power, a refrigeration system that can save energy can be realized.

  In addition, although the capacity | capacitance control of the compressor in a refrigeration apparatus may be what controls a capacity | capacitance in steps, in the case of a capacity | capacitance control of a compressor in stages, it is necessary to keep outlet temperature constant in a refrigeration apparatus Therefore, the flow rate of the primary pump can also be controlled only within a certain range. For this reason, it is difficult to equalize the flow rates of the primary pump and the secondary pump, the flow rate flowing through the bypass pipe 11 cannot be eliminated, and the pump consumes extra power and wastes conveyance power. Occur.

  In the above embodiment, since the compressor is continuously capacity-controlled, the flow rates of the primary pump and the secondary pump can be made equal. For this reason, compared with the case where the capacity of the compressor is controlled in stages, waste of the conveyance power of the secondary pump can be further reduced.

  Further, by using the above embodiment, the controller (control means) 12 for controlling the primary side A equipment of the refrigeration system is controlled independently of the secondary side controller for controlling the secondary side B equipment. Therefore, even when only the refrigeration apparatus 1a to 1d of the refrigeration system is replaced with a new refrigeration apparatus, it is not necessary to be the same as the refrigeration apparatus before the replacement, and can be appropriately replaced with a favorite refrigeration apparatus There is also an effect that an optimum refrigeration apparatus with high energy saving can be selected.

  In the above-described embodiment, the flow rate of the primary pumps 5a to 5d is controlled to be increased or decreased equally. However, the flow rates of the primary pumps 5a to 5d are increased or decreased differently. Even in this case, if the flow rate flowing through each refrigeration unit and the outlet side temperature thereof are taken into consideration, the average value of the outlet side temperatures in the operating refrigeration unit among the plurality of refrigeration units (from the plurality of refrigeration units) It is possible to determine the temperature at which the secondary refrigerant is mixed. Therefore, the present invention can also be applied to refrigeration systems in which the flow rates of the primary pumps 5a to 5d are different.

  Moreover, in the said Example, the secondary refrigerant | coolant was water, and it demonstrated as a refrigeration system which cools this water with a refrigeration apparatus, and supplies it to a load, but a secondary refrigerant | coolant can also use brine, air, etc. It is.

  Furthermore, the present invention can be similarly applied not only to cooling a load but also to a refrigeration system for heating a load as described above.

1a to 1d ... refrigeration devices 2a to 2d ... heat exchangers 3a to 3d ... inlet side temperature detection means (thermistor for inlet temperature detection)
4a to 4d: outlet side temperature detection means (outlet temperature detection thermistor)
5a to 5d ... primary side pumps 6a to 6d ... secondary side pump 7 ... upstream header, 8 ... downstream header, 9 ... intermediate header 10 ... load upstream side temperature detection means (thermistor for detecting junction temperature)
11 ... Bypass pipe 12 ... Controller (control means)
13 ... Load inlet temperature detector 14 ... Load outlet temperature detector 15 ... Flow control valve 16 ... Relief valve 20 ... Load.

Claims (12)

Secondary refrigerant from a plurality of refrigeration units provided in parallel on the primary side flows in, an upstream header provided on the upstream side of the load, and the secondary refrigerant from the load provided on the downstream side of the load A downstream header for distributing the refrigerant to the plurality of refrigeration devices, a primary pump for individually supplying the secondary refrigerant of the downstream header to the refrigeration devices, and the upstream header In a refrigeration system comprising a secondary pump for supplying a secondary refrigerant to the load, and a bypass pipe connecting the upstream header and the downstream header,
Flow rate detection means for detecting the flow rate of the secondary refrigerant flowing through each of the refrigeration devices;
Inlet-side temperature detection means for detecting the temperature of the secondary refrigerant flowing into each refrigeration apparatus;
Outlet side temperature detection means for detecting the temperature of the secondary refrigerant flowing out from each of the refrigeration devices;
Load upstream side temperature detection means for detecting the temperature of the secondary refrigerant between the upstream header and the load;
When the temperature detected by the load upstream side temperature detection means is higher than the temperature detected by the outlet side temperature detection means in the operating refrigeration apparatus among the plurality of refrigeration apparatuses, the primary side is When the temperature detected by the inlet side temperature detection means in the refrigeration apparatus in operation among the plurality of refrigeration apparatuses is lower than a predetermined temperature, the flow rate of the entire secondary refrigerant flowing is controlled to increase. And a control means for controlling the overall flow rate of the secondary refrigerant flowing on the primary side to decrease.   2. The refrigeration system according to claim 1, wherein the temperature detected by the load upstream-side temperature detection means is the outlet-side temperature detection means in the refrigeration apparatus in operation among the plurality of refrigeration apparatuses. If the flow rate in the operating refrigeration system is lower than the maximum flow rate when the temperature is higher than the average value detected in step 3, the flow rate is increased and the flow rate in the operating refrigeration unit is at the maximum flow rate. Then, the refrigeration system characterized by controlling to operate the frozen refrigeration apparatus.   3. The refrigeration system according to claim 1, wherein the control means has a temperature detected by the inlet side temperature detection means in the operating refrigeration apparatus of the plurality of refrigeration apparatuses being lower than a predetermined temperature. If the flow rate in the operating refrigeration apparatus is higher than the minimum flow rate, the flow rate is decreased, and if the flow rate in the operating refrigeration apparatus is the minimum flow rate, the operating refrigeration apparatus is stopped. A refrigeration system characterized by being controlled as follows. Secondary refrigerant from a plurality of refrigeration units provided in parallel on the primary side flows in, an upstream header provided on the upstream side of the load, and secondary refrigerant from the load provided on the downstream side of the load. A downstream header for distribution to the plurality of refrigeration apparatuses, a primary pump for individually supplying the secondary refrigerant of the downstream header to the refrigeration apparatuses, and a secondary refrigerant of the upstream header In a refrigeration system comprising a secondary pump for supplying the load to the load, and a bypass pipe connecting the upstream header and the downstream header,
Flow rate detection means for detecting the flow rate of the secondary refrigerant flowing through each of the refrigeration devices;
Inlet side temperature detection means for detecting the temperature of the secondary refrigerant flowing into each refrigeration apparatus;
Outlet side temperature detection means for detecting the temperature of the secondary refrigerant flowing out from each of the refrigeration devices;
Load upstream side temperature detection means for detecting the temperature of the secondary refrigerant between the upstream header and the load;
The temperature detected by the load upstream side temperature detecting means is compared with the temperature detected by the outlet side temperature detecting means in the operating refrigeration apparatus of the plurality of refrigeration apparatuses, and the plurality of refrigeration units The flow rate of the secondary refrigerant flowing through the bypass pipe by comparing the temperature detected by the inlet side temperature detecting means in the operating refrigeration unit of the device with a predetermined temperature or load outlet side temperature determined in advance. And a control means for controlling the flow rate of the secondary refrigerant flowing on the primary side so as to decrease the refrigeration system.   The refrigeration system according to any one of claims 1 to 4, wherein the secondary side according to a temperature difference between a temperature of the secondary refrigerant flowing into the load and a temperature of the secondary refrigerant flowing out of the load. A refrigeration system in which the flow rate of the pump is controlled.   6. The refrigeration system according to claim 5, wherein the secondary pump includes a plurality of pumps, and includes a temperature of the secondary refrigerant flowing into the load and a temperature of the secondary refrigerant flowing out of the load. The refrigeration system, wherein the flow rate of the entire secondary pump is controlled so that the temperature difference becomes a predetermined temperature difference.   7. The refrigeration system according to claim 5, wherein the secondary pump has a pump whose rotation speed is continuously controlled.   The refrigeration system according to any one of claims 1 to 7, wherein the refrigeration apparatus includes a compressor capable of continuously changing an operation capacity so that an outlet side temperature of the refrigeration apparatus becomes a predetermined temperature. The refrigeration system, wherein the compressor capacity is controlled.   The refrigeration system according to any one of claims 1 to 8, wherein the primary pump is a pump whose rotation speed is continuously controlled, and each refrigeration is performed by changing the rotation speed of the primary pump. A refrigeration system characterized by controlling a flow rate through the apparatus.   The refrigeration system according to any one of claims 1 to 9, wherein the load upstream side temperature detecting means detects a temperature of a secondary refrigerant in the upstream header.   The refrigeration system according to any one of claims 1 to 10, wherein the flow rate detection means for detecting the flow rate of the secondary refrigerant flowing through each refrigeration apparatus supplies the secondary refrigerant to each refrigeration apparatus. A refrigeration system for calculating a flow rate based on a rotational speed of a pump.   12. The refrigeration system according to claim 1, wherein the control means is provided in each refrigeration apparatus and is incorporated in a control board for controlling each refrigeration apparatus. system.

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