JP2020128870A - System and method for operating refrigeration system - Google Patents

Abstract

To provide a method and system for operating a refrigeration system to refrigerate a product.SOLUTION: A first temperature of a refrigerant at a downstream side of a condenser and an upstream side of an evaporator may be obtained. A first pressure of the refrigerant at the downstream side of the condenser and the upstream side of the evaporator may be obtained. A second pressure of the refrigerant at a downstream side of the evaporator and an upstream side of a compressor and/or a temperature of a product being refrigerated may be obtained. A first valve, that is disposed between the condenser and the evaporator, may be controlled based on the first temperature and the first pressure to maintain a predetermined refrigerating set value for a refrigeration system. A second valve of the refrigeration system, which is connected to the compressor, may be controlled based on the second pressure or the temperature of the product to optimize a capacity of the compressor of the refrigeration system.SELECTED DRAWING: Figure 1

Description

The present disclosure relates generally to cooling systems, and more particularly to methods of operating cooling systems more efficiently.

Cooling systems are commonly used to cool, store, and store products such as milk, juice, and fruits. Conventional cooling systems typically use a closed loop process in which refrigerant is constantly circulated through a condenser, expansion valve, evaporator, and compressor. The condenser cools the refrigerant and condenses it into a saturated liquid. The saturated liquid refrigerant then moves through the expansion valve, which reduces the pressure of the refrigerant and also the temperature. The refrigerant then passes through the evaporator, at which point the saturated liquid refrigerant extracts or absorbs heat from the external fluid (eg milk, air, water), thereby cooling the external fluid. Extraction or absorption of heat from the external fluid evaporates the refrigerant and transforms it into a superheated gas refrigerant. The superheated gas refrigerant then flows into the compressor which increases the pressure and temperature of the refrigerant. The vapor refrigerant then returns through the condenser and the cycle begins again.

However, there are many problems associated with this conventional cooling system. For example, these conventional cooling systems may form ice on the surface of the evaporator at low flow rates and/or if the external fluid should be cooled to near freezing temperatures. Ice formation can damage the evaporator, reduce the cooling capacity of the system, and increase energy consumption instead. Furthermore, these conventional cooling system components are typically switched on immediately after switching off, leading to inefficiencies and increased energy consumption. For example, compressors typically cycle on and off based on the coolant temperature. Not only is this cycling inefficient, but in practice the temperature of the coolant can be very unstable, which can make it very difficult to maintain the desired product temperature. .. Moreover, since the capacity of the condenser depends on the condition of the evaporator (for example, the desired temperature of the product being cooled), this limits the available system capacity when the temperature of the product to be cooled is high, In this way, the duration of the cooling cycle is increased and so is the energy consumption.

One aspect of the present disclosure provides a method of operating a cooling system for cooling a product. The cooling system comprises a condenser, an evaporator downstream of the condenser, a compressor downstream of the evaporator, and a refrigerant flowing through the cooling system. The method includes obtaining a first temperature of a refrigerant downstream of a condenser and upstream of an evaporator from a first converter coupled to a cooling system. The method includes obtaining a first pressure of the refrigerant downstream of the condenser and upstream of the evaporator from a second converter coupled to the cooling system. The method also includes obtaining a second pressure of the refrigerant downstream of the evaporator and upstream of the compressor or a temperature of the product being cooled from a third converter coupled to the cooling system. The method includes a processor, communicatively coupled to the cooling system, between the condenser and the evaporator based on the first temperature and the first pressure to maintain a predetermined cooling set point for the cooling system. A second cooling system connected to the compressor is controlled based on the second pressure or the product temperature to control the opening degree of the arranged first valve and to optimize the capacity of the compressor. Further comprising controlling the valve.

Another aspect of the disclosure provides a cooling system for cooling a product. The cooling system comprises a condenser, an evaporator located downstream of the condenser, a compressor located downstream of the evaporator, first, second and third converters, and a controller. The first converter is located immediately downstream of the condenser and is configured to obtain a first temperature of the refrigerant downstream of the condenser and upstream of the evaporator. The second converter is located immediately downstream of the condenser and is configured to obtain a first pressure of the refrigerant downstream of the condenser and upstream of the evaporator. The third converter is arranged immediately downstream of the evaporator and is arranged to obtain a second pressure of the refrigerant downstream of the evaporator and upstream of the compressor or the temperature of the product to be cooled. The controller is communicatively coupled to the first, second, and third converters. The controller, based on the obtained first temperature and first pressure, maintains a first cooling position downstream of the condenser and upstream of the evaporator to maintain the preset cooling setpoint. Control a second control valve connected to the compressor, based on the obtained second pressure or product temperature, in order to optimize the capacity of the compressor. Is configured as follows.

Yet another aspect of the disclosure provides a method of operating a cooling system to cool a product, the cooling system comprising a condenser, an evaporator downstream of the condenser, a compressor downstream of the evaporator. , And a refrigerant flowing through the cooling system. The method comprises obtaining a first temperature of the refrigerant downstream of the condenser and upstream of the evaporator from a first converter connected to the cooling system, from a second converter connected to the cooling system, Obtaining a first pressure of the refrigerant downstream of the condenser and upstream of the evaporator, and from a third converter coupled to the cooling system, a first refrigerant pressure downstream of the evaporator and downstream of the compressor. Including obtaining a pressure of 2 or the temperature of the product to be cooled. The method involves vaporizing a condenser and an evaporator so that the evaporator is flooded with liquid refrigerant by a processor communicatively coupled to the cooling system based on temperature and pressure to maintain a predetermined cooling set point for the cooling system. To control the opening of an electronic stepper valve located between the compressor and a processor communicatively coupled to the cooling system to optimize pressure or product temperature to optimize compressor performance. Based on the above, the method further includes controlling a solenoid valve connected to the compressor.

1 is a schematic diagram of a cooling system assembled in accordance with the teachings of the present disclosure. FIG. 2 is a schematic view of an intelligent control board that can be connected to the cooling system shown in FIG. 1. 3 is a schematic diagram illustrating the intelligent control board shown in FIG. 2 communicatively coupled to the cooling system shown in FIG. 1. 6 is a process flow diagram illustrating one form of a method of operating a cooling system in accordance with the present disclosure.

FIG. 1 illustrates a schematic diagram of a cooling system 100 assembled in accordance with the teachings of the present disclosure. The cooling system 100 is a closed loop system in which a refrigerant or coolant constantly circulates as part of the refrigeration or cooling cycle. The cooling system 100 of the present embodiment can be used, for example, in a dairy farm to cool or cool milk, but instead, a commercial facility (eg in a supermarket), an industrial facility (eg in a power plant). , Or milk and/or other products (eg juice, yogurt, meat, cheese, etc.) can be chilled or used elsewhere for chilling.

The closed loop cooling system 100 generally includes a condenser 104, a first control valve 108, an evaporator 112, an accumulator/heat exchanger 116, a second control valve 120, a compressor 124, and a condenser fan 128. As shown, generally conventional tubing 101 extends between each of these components and carries the refrigerant in a conventional manner. The condenser 104 is generally configured to condense the refrigerant into a high pressure liquid to subcool it. The supercooled high-pressure liquid flows from the condenser 104 to the first control valve 108 through the conduit 132 of the pipe 101. The first control valve 108 is an electronic stepper valve that in this embodiment can be moved between a closed position and a plurality of different open positions (eg, 0 to 2500 different positions) to reduce the pressure of the refrigerant. 136, which converts the refrigerant from a high pressure liquid to a low pressure liquid. The low pressure liquid refrigerant then flows from electronic stepper valve 136 to evaporator 112 through conduit 140 of line 101. As described in more detail below, the opening through the first control valve 108 ensures that the refrigerant exiting the condenser 104 is sufficiently subcooled so that the evaporator 112 is flooded with liquid refrigerant. Can be controlled to provide saturated suction as a result.

When the illustrated form of the cooling system 100 is installed on a dairy farm, the evaporator 112 is attached to a milk cooler 114 that is used to collect and cool milk from the milking process. Therefore, as the liquid refrigerant passes through the evaporator 112, the saturated liquid refrigerant extracts or absorbs heat from the milk chiller, thereby cooling the milk and evaporating the refrigerant. However, unlike conventional evaporators that completely evaporate the refrigerant, the evaporator 112 only partially evaporates the refrigerant because it is flooded with liquid refrigerant and provides saturated suction. As such, as the refrigerant exits the evaporator 112, it occupies a partially liquid/partly gas phase.

To prevent the liquid from reaching the compressor 124, the liquid/gas mixture flows from the evaporator 112 to the accumulator/heat exchanger 116 through conduit 144 of line 101. As shown in FIG. 1, the accumulator/heat exchanger 116 is in thermal communication with a conduit 132 from the condenser that carries the supercooled refrigerant. Conduit 132 thus cools the liquid/vapor mixture carried in conduit 144 and the cooled liquid falls to the bottom of accumulator/heat exchanger 116. The steam flows to the compressor 124. At this point, the refrigerant is in vapor or gas form, but at a lower superheat temperature (eg, 1 to 5 degrees Fahrenheit) than is typically found in conventional refrigeration systems. The vapor refrigerant then flows through conduit 148 of line 101 from accumulator/heat exchanger 116 to compressor 124. The second control valve, which in this form may be a solenoid valve 150, is connected to the compressor 124 by conduits 121, 123. As described in more detail below, the second valve 120 can be controlled to offload or load the compressor 124 to change the capacity of the compressor 124, if desired. The advantage of using a solenoid valve is that it has a very immediate effect due to the short distance and time of movement of the valve element between the open and closed positions.

The compressor 124 compresses the vapor refrigerant, thereby increasing the pressure and temperature of the vapor refrigerant. The vapor refrigerant then returns from compressor 124 to condenser 104 through conduit 152 of line 101, allowing air) to pass through condenser 104, thereby cooling the refrigerant flowing through condenser 104. Is located adjacent to or near the condenser 104. The condenser fan 128 is driven by a condenser fan motor 156 coupled to the condenser fan 128. The condenser fan motor 156 is itself controlled (eg, driven) by a fan control drive 160 that is communicatively coupled to the fan motor 156. As described in more detail below, the fan control drive 160 is controlled to control the condenser fan motor 156 and thereby the speed of the condenser fan 128 to maintain or achieve the desired condensing temperature. can do.

Still referring to FIG. 1, the cooling system 100 is generally configured to obtain (eg, detect, sense) data such as pressure, temperature, flow rate, etc. that is indicative of operation and performance of the cooling system 100. Further transducers (eg, sensors). In this form, the cooling system 100 includes a first pressure converter 204, a first temperature converter 208, a second pressure converter 212, and a second temperature converter 216. It will be appreciated that the temperature and pressure transducers 204-216 may generally be any commercially available sensor such as, for example, the 2CP5 sensor manufactured by Sensata Technologies.

The first pressure transducer 204 is located downstream of the condenser 104, or in the conduit 132 between the condenser 104 and the first control valve 108 (ie, in the high pressure section of the system 100). So positioned, the first pressure transducer 204 is configured to obtain the pressure of the refrigerant exiting the condenser 104 (referred to herein as the first pressure of the refrigerant). In the illustrated form of system 100, the first temperature converter 208 also includes a conduit downstream of the condenser 104 between the condenser 104 and the first control valve 108 (ie, in the hot zone of the system 100). 132 or in the middle thereof. Furthermore, in this form, the first temperature converter 208 is upstream of the first pressure converter 204, but in other forms, the converter 208 may be downstream of the converter 204. So positioned, the first temperature converter 208 is configured to obtain the temperature of the refrigerant exiting the condenser 104 (referred to herein as the first temperature of the refrigerant). The second pressure converter 212 is disposed downstream of the evaporator 112, or in the conduit 144 between the evaporator 112 and the accumulator/heat exchanger 116 (ie, in the low pressure section of the system 100). So positioned, the second pressure transducer 212 is configured to obtain the pressure of the refrigerant exiting the evaporator 112 (referred to herein as the second pressure of the refrigerant). The second temperature converter 216, also referred to herein as a product temperature converter, is generally used in the vicinity of the product to be cooled to obtain the temperature of the product to be cooled (eg, milk). Or in the product. Because the cooling system 100 of this embodiment is used to cool milk, the product temperature converter 216 of this embodiment is located near, above, or in the milk cooler containing the milk to be cooled.

It should be appreciated that the cooling system 100 described in FIG. 1 can vary widely and still be included within the principles of the present disclosure. In other forms, the cooling system 100 can include additional, different, or fewer components than those described above. The first control valve 108 can be, for example, an expansion valve or any other suitable control valve. In some forms, the cooling system 100 can include a conventional evaporator that produces a superheated vapor refrigerant instead of the disclosed evaporator 112 that produces a mixed vapor-liquid refrigerant. The evaporator 112 need not be mounted in the milk cooler 114. Alternatively, the evaporator 112 may be attached to the outer surface of the milk chiller 114 or otherwise coupled to the milk chiller 114 (eg, via a conduit or line). When the cooling system 100 is used to cool anything other than milk or something else in addition to milk, the evaporator 112 is mounted in a different external environment, such as a display case containing one or more products to be cooled. Or they can be linked. In a configuration where the cooling system 100 includes a conventional evaporator, the cooling system 100 does not include the accumulator/heat exchanger 116 because the refrigerant will be completely evaporated in the evaporator before it reaches the compressor 124. Good. In some forms, the cooling system 100 may not include the second control valve 120, in which case the cooling system 100 would not allow adjustment of the capacity of the compressor 124. In other forms, the cooling system 100 can include additional, different, or fewer converters. By way of example, the cooling system 100 may not include both the second pressure converter 212 and the second temperature converter 216. As another example, the cooling system 100 can include an additional temperature transducer adjacent to or near the second pressure transducer 212. Moreover, any of the converters 204-216 may be located elsewhere to still perform the intended function described above.

FIG. 2 illustrates one form of intelligent control board 250 that may be communicatively coupled or connected to the cooling system 100 to improve the performance of the cooling system 100. The intelligent control board 250 generally includes a controller 254 configured to monitor and control the operation of the cooling system 100 and a panel 258 that includes one or more indicators that provide visual feedback about the operation of the cooling system 100. ..

As shown in FIG. 2, the controller 254 includes a processor 262, a memory 266, a communication interface 270, and calculation logic 274. The processor 262 can be a general processor, a digital signal processor, an ASIC, a field programmable gate array, a graphics processing unit, an analog circuit, a digital circuit, or any other known processor or later developed processor. .. Processor 262 operates according to instructions in memory 266. Memory 266 can be volatile memory or non-volatile memory. The memory 266 may include one or more of read only memory (ROM), random access memory (RAM), flash memory, electronic erasable program read only memory (EEPROM), or other type of memory. The memory 266 may include optical, magnetic (hard drive), or any other form of data storage device.

Communication interface 270 is provided to facilitate electronic communication between controller 254 and components of cooling system 100. The communication interface 270 may be, for example, one or more Universal Serial Bus (USB) ports, one or more Ethernet ports, and/or one or more other ports or interfaces. Can be included. Electronic communication occurs via any known communication protocol including, by way of example, USB, RS-232, RS-485, WiFi, Bluetooth, and/or any other suitable communication protocol. sell.

Logic 274 typically includes one or more control routines and/or one or more subroutines embodied as computer readable instructions stored on memory 266. The control routines and/or subroutines may perform PID (proportional-integral-derivative), fuzzy logic, non-linear, or any other suitable type of control. Processor 262 generally executes logic 274 to perform actions related to operation of cooling system 100. Logic 274, when executed, causes processor 262 to (i) obtain data (eg, pressure data, temperature data) from one or more transducers 204-216, (ii) a predetermined level of subcooling. Controlling the first control valve 108 of the cooling system 100 based on the obtained data to maintain, (iii) cooling based on the obtained data to optimize the capacity of the compressor 124. Controls the second control valve 120 of the system 100. (Iv) controlling fan control drive 160 and thus condenser fan 128 based on the obtained data to adjust the condensing temperature of condenser 104; (v) detecting a fault condition or error in cooling system 100. And/or perform other desired functions.

Although not shown herein, controller 254 also includes one or more bit switches to allow a user of cooling system 100 to select from a number of various programmed options associated with various functions of cooling system 100. May be included. Programmed options include, for example, an anti-short cycle that prevents premature cycling of compressor 124, and an alarm or fault that provides visual feedback (eg, by panel 258) when an alarm or fault condition is detected. It may include a status output. A user of the cooling system 100 can activate (or deactivate) one or more various functions of the cooling system 100 by selecting the bit corresponding to the desired option.

As shown in FIG. 2, the panel 258 of the present embodiment includes two light emitting diodes (LEDs) 278, 282 configured to provide visual feedback on the operation of the cooling system 100. When the controller 254 detects a fault or alarm condition in the cooling system 100, the LED 278 emits red light (ie, light having a wavelength range of 620 to 750 nm) through the hole 286 of the control board 250. The LED 278 can emit a red light or a series of red lights (ie, blinking red light) depending on the detected fault condition. LED 278 may be, for example, one red light if the failure condition is a bit switch setting error, two blinks of red light if the failure condition is for converter 208, and a failure condition is for converter 212. Flashing red light three times in some cases, flashing red light four times if the fault condition is with respect to the temperature converter 220, and red light if the fault condition is with the fan control drive 160. It can flash seven times. On the other hand, the LED 282 emits green light (that is, light having a wavelength in the range of 490 to 570 nm) through the hole 290 of the control board 250. The LED 282 may emit one green light or a series of green lights (ie blinking green light) depending on the operating state. The LED 282 may, for example, always emit continuous green light as long as the cooling system 100 is in operation and operating normally, but may emit a single flash of green light when the anti-cycle option is enabled.

Although not described herein, the components of intelligent control board 250 can be arranged in any known manner. Those skilled in the art will also appreciate that control board 250 may include additional or different components. For example, the controller 254 can include additional components not explicitly shown herein, such as repeaters, converters, or meters. For example, the panel 258 provides more or fewer LEDs, LEDs that emit different colors of light, LEDs that emit different patterns of light (eg, corresponding to different fault conditions), visual feedback. Various light sources for user control, and/or a user interface, and/or some other means for providing visual feedback about the operation of the cooling system 100.

FIG. 3 is a schematic diagram illustrating an intelligent control board 250 coupled or connected to the cooling system 100. As shown, the control board 250 is connected to the fan control driver 160 by the communication network 300, the first control valve 108 by the communication network 304, the second control valve 120 by the communication network 308, and the second control valve 120 by the communication network 312. One pressure transducer 204, a communication network 316 to a first temperature transducer 208, a communication network 320 to a second pressure transducer 212, and a communication network 324 to a second temperature transducer 216, respectively. Or connected. As used herein, the phrases "in communication" and "coupled" are meant to be directly connected or indirectly connected through one or more intermediate components. Is defined. Such intermediate components may include hardware and/or software based components.

Networks 300-324 may be wireless networks, wired networks, or a combination of wired and wireless networks (eg, cellular and/or 802.11x compliant networks), publicly accessible networks such as the Internet, i. It is to be understood that it may include generic networks, or a combination thereof. The types and configurations of the networks 300-324 are implementation dependent and facilitate any of the described communication between the intelligent control board 250 and the components of the cooling system 100, any type currently available or later developed. Communication networks can be used.

With the intelligent control board 250 coupled or connected to the cooling system 100 in this manner, the controller 254 includes any of the fan control drive 160, the first control valve 108, the second control valve 120, and the converters 204-216. The crab is configured to send signals (eg, control signals, data requests) and receive signals (eg, data) from them. Controller 254 can thus communicate with converters 204-216 to control fan control drive 160, first control valve 108, and second control valve 120.

The converters 204-216 are associated with the operation of the cooling system 100 (ie, the cooling cycle) of the cooling system 100 when the cooling system 100 is operational and refrigerant circulates through the components of the cooling system in the manner described above. Data can be obtained which is indicative of operation. Specifically, the first pressure converter 204 obtains (eg, detects and measures) the pressure of the refrigerant downstream of the condenser 104 and upstream of the valve 108 (ie, the first pressure of the refrigerant). And the first temperature converter 208 can obtain the temperature of the refrigerant downstream of the condenser 104 and upstream of the valve 108 (ie, the first temperature of the refrigerant), and the second pressure converter 212. Obtains the pressure of the refrigerant downstream of the evaporator 112 and upstream of the accumulator/heat exchanger 116 (ie the second pressure of the refrigerant) and the second temperature converter 216 changes the temperature of the product to be cooled. They may be obtained or they may be combined. The above data may be obtained automatically when the cooling system 100 is operational and/or in response to a request received from the controller 254. The above data can be obtained at the same time (eg, the first temperature and the first pressure can be obtained simultaneously), at different times, or a combination thereof (eg, some data at different times). While you can get some of the data at the same time).

The controller 254 can then obtain the data obtained by one or more of the converters 204-216 via the respective networks 312-328. The data can be automatically sent to controller 254 and/or can be sent to controller 254 in response to a request received from controller 254. Once the data is available, the data can be stored in memory 266 or other memory.

Based on or utilizing the data obtained, the controller 254 causes the components of the cooling system 100, in particular the first control valve 108, the second control valve 120, and/or the fan control drive 160. Can be controlled (eg, adjusted). The controller 254 is generally configured to control the components of the cooling system 100 so that the cooling system 100 operates in the desired manner described herein.

The controller 254 controls (eg, closes or adjusts opening) a first control valve, which in the illustrated form is in the form of an electronic stepper valve 136, based on a first temperature and a first pressure. You can This is done to maintain a predetermined (eg, factory programmed) cooling setpoint for the cooling system 100. The predetermined cooling setpoint corresponds to the desired subcooling level for the refrigerant as it exits the condenser 104. The desired subcooling level corresponds to the subcooling level at which the evaporator 112 desirably overflows with liquid refrigerant. In this way, flooding the evaporator 112 provides a saturated suction exiting the evaporator 112, with the refrigerant in the liquid/vapor state of the mixture and at a lower temperature than normally found in conventional refrigeration systems. Will result in leaving. Beneficially, this improves the efficiency of the evaporator 112, keeps the motor of the compressor 124 cooler, and improves the volumetric efficiency of the compressor 124.

To determine whether the cooling system 100 is operating at, below, or above this predetermined cooling set point, the controller 254 controls the first pressure and the first temperature. Based on, the current supercooling level of the refrigerant as it exits the condenser 104 can be calculated. In some forms, the controller 254 correlates the first pressure to the expected temperature and then compares the expected temperature to the measured temperature, i. You can calculate the level. The controller 254 can then compare the calculated refrigerant subcooling level to a predetermined cooling setpoint. When the calculated subcooling level is at least substantially equal (eg, equal) to the predetermined cooling setpoint, the controller 254 need not control (eg, adjust) the first control valve, The controller 254 determines that the cooling system 100 is operating substantially at this predetermined cooling set point. However, if the calculated current subcooling level is determined to be less than or greater than the predetermined cooling setpoint, then controller 254 determines that the current subcooling level is substantially equal to the predetermined cooling setpoint ( Controller 254 adjusts (eg, opens, closes) first control valve 108 until a desired level of subcooling is achieved and maintained). By further opening valve 108, more refrigerant will flow through and the result of supercooling in condenser 104 will be higher temperature refrigerant. On the other hand, closing the valve 108 or reducing the opening of the valve 108 reduces the flow through the conduit 132, thus reducing the pressure and temperature of the supercooled refrigerant exiting the condenser 104. It should be appreciated that control of the first control valve 108 is an iterative, continuous process. In this configuration, the control valve 108 is or includes an electronic stepper valve 136 having 2500 different positions to facilitate fine tuning. Of course, other types of adjustable port valves may be used.

The controller 254 can control the second control valve 120, which in the illustrated form is in the form of a solenoid valve 150, based on the second pressure and/or the temperature of the product to be cooled. This is done to control the capacity of compressor 124. As discussed briefly above, when system capacity is too low (eg, when the temperature of the product being cooled is higher than expected), conventional systems compensate by increasing the duration of the cooling cycle, thereby , Increase energy consumption. Conversely, when the system capacity is too high (eg, under cold flow conditions when the temperature of the product being cooled is lower than expected), the product being cooled may freeze. The system 100 disclosed herein advantageously prevents either situation by controlling (eg, adjusting) the capacity of the compressor 124 according to the operating conditions of the cooling system 100.

To determine if the capacity of the compressor 124 needs to be adjusted, the controller 254 determines a second pressure (pressure of the refrigerant as it exits the evaporator 112) or product temperature to a predetermined (eg, factory programmed). A second pressure setpoint or a product temperature setpoint). This predetermined set value corresponds to a desirable, if not ideal, compressor 124 capacity. When the second pressure or product temperature is substantially equal to the predetermined second pressure or product temperature set point, the controller 254 indicates that the current compressor 124 capacity is adequate (until less than ideal). Also, the controller 254 does not control the solenoid valve 150. However, when the second pressure or product temperature is less than or greater than the predetermined second pressure or product temperature setpoint, the controller 254 controls the compressor 124 to have a controlled reduction or a controlled increase (capacity in advance). Solenoid valve 150 may be controlled to provide (if reduced).

In particular, when the second pressure or product temperature is less than the predetermined second pressure or product temperature set point, controller 254 energizes solenoid valve 150 to open solenoid valve 150, thereby removing the load and compressor 124. Reduce the ability of. The controller 254 energizes the solenoid valve 150 for at least a minimum predetermined time (eg, 1 second), but the controller 254 controls the solenoid valve 150 for a maximum predetermined time (eg, 9 seconds) to protect the compressor 124. The solenoid valve 150 can be energized until the second pressure or product temperature is greater than a predetermined second temperature or product temperature set point, except that the solenoid valve 150 can be energized. The controller 254 may suspend the control of the first control valve 108 and the condenser fan 128 at the same time when the solenoid valve 150 is energized.

Conversely, when the second pressure or product temperature is greater than the predetermined second pressure or product temperature set point, controller 254 deenergizes solenoid valve 150 to close solenoid valve 150, thereby reducing the load. The capacity of the cross compressor 124 is improved. The controller 254 deenergizes the solenoid valve 150 for at least a minimum predetermined time (eg, 3 seconds), but until the second pressure or product temperature is less than a predetermined second pressure or product temperature set point. 150 can be de-energized.

In the above description, the solenoid has been described as being opened when energized, but itself constitutes a normally closed solenoid. One advantage of the normally closed solenoid is that energy is needed only to unload the compressor 124. However, in other configurations, a normally open solenoid that is closed when energized can be used.

It should be appreciated that, like the electronic stepper valve 136, control of the solenoid valve 150 is an iterative, continuous process. Indeed, how fast the second pressure (the pressure obtained by the second pressure transducer 212) drops when the compressor 124 is loaded, provided that such control is subject to the minimum and maximum durations described above. The controller 254 can self-adjust the control of the solenoid valve 150 based on how fast the second pressure rises when the compressor 124 is unloaded.

At least initially (eg, when the controller 254 first receives the activation signal), the fan control drive 160 activates the condenser fan 128 for a short time (eg, 3 seconds) full time. However, after this short period of time, the controller 254 can control the fan control drive 160 based on the first pressure to control (eg, adjust) the speed of the condenser fan 128. When the first pressure rises to a predetermined pressure point (eg, 170 psi), the fan control drive 160 can control the fan 128 to operate at a predetermined minimum speed. The fan control drive 160 may increase the speed of the fan 128 when the first pressure is above this predetermined pressure point and until the first pressure reaches a predetermined maximum pressure point (eg, 230 psi). When the first pressure reaches the predetermined maximum pressure point, the fan 128 is operating at full speed and any pressure above this predetermined maximum pressure does not affect the speed of the fan 128. Controlling the speed of fan 128 in this manner allows cooling system 100 to operate in a more stable manner during lower or cooler ambient conditions.

In this embodiment, the controller 254 can simultaneously control the electronic stepper valve 136, the solenoid valve 150, and the fan control drive device 160. As such, the controller 254 can open the electronic stepper valve 136 and simultaneously energize the solenoid valve 150. However, in other forms, controller 254 may only control two or more of electronic stepper valve 136, solenoid valve 150, and fan control drive 160 at different times. In a further form, controller 254 may only control one or two of electronic stepper valve 136, solenoid valve 150, and fan control drive 160, rather than all.

Controller 254 can instruct panel 258 to provide visual feedback on the operation of cooling system 100. As mentioned above, when the controller 254 detects one or more fault or warning conditions, the controller 254 can instruct the LED 278 of the panel 258 to emit one or a series of lights. In some cases, the controller 254 can detect one or more faults or warning conditions based on the data obtained. The pressure and/or temperature data can indicate, for example, transducer 204, transducer 208, transducer 212, and/or transducer 216 are not functioning properly. The controller 254 can detect that the condenser fan 128, the fan motor 132, and/or the fan control drive 160 are not functioning properly due to the connection with the fan control drive 160. In some cases, controller 254 may detect a problem in one of networks 300-324 connecting controller 254 to various components of cooling system 100. Alternatively or additionally, the controller 254 can detect that the bit switch is not functioning properly or was not set properly. Alternatively or additionally, the controller 254 directs the LED 282 of the panel 258 to emit continuous green light when the cooling system 100 is operating normally, with the anti-cycle option enabled. At some time, the LED 282 of the panel 258 can be instructed to emit a single blink of green light. In turn, panel 258 can provide the requested visual feedback as indicated by LEDs 278, 282. Therefore, the user of the cooling system 100 can easily and quickly confirm the problem regarding the control process of the cooling system 100.

Similarly, as described in FIG. 3, in some cases, communication network 354 may couple or connect portable diagnostic tool 350 to intelligent control board 250. The communication network 354 can be a wireless network, a wired network, or a combination thereof. The portable diagnostic tool 350 can include a processor, memory, one or more input devices (eg, keyboard), a display, and/or other components known in the art. In any event, the portable diagnostic tool 350 allows the user of the cooling system 100 to install the intelligent control board 250, configure various components of the system 100 (e.g., controller 254), and to determine the operational status of the cooling system 100 in real time. To be able to monitor.

FIG. 4 illustrates one form of method or process for operating the cooling system 100 of the present disclosure. Although the methods or processes are described below as being performed by or using converters 204-216 and controller 254, the methods or processes may instead be performed by some other component. Although a method or process is described as including various tasks that are performed in sequence, some of the method or process tasks may be performed concurrently, and some or all may be performed in different orders. It should be understood. In other forms, the method or process may include additional, fewer, or different tasks, or different order of tasks. By way of example, one or more of the tasks (eg, the task of obtaining a first temperature, the task of obtaining a first pressure, the task of obtaining a second pressure) may be repeated many times.

In one form, referring to the “block” of FIG. 4, the method comprises (i) a first converter (eg, converter 208) coupled to the cooling system 100 to a condenser (eg, condenser 104). Obtaining a first temperature of the refrigerant exiting the block (block 400), (ii) a first pressure of the refrigerant exiting the condenser from a second converter (eg, converter 204) coupled to the cooling system 100. (Block 404), and (iii) a second converter of refrigerant that exits the evaporator (eg, evaporator 112) from a third converter (eg, converter 212 or 216) coupled to the cooling system 100. Obtaining the pressure or the temperature of the product to be cooled (block 408). In some forms, obtaining the second pressure or product temperature comprises obtaining the second pressure (eg, by the transducer 212), while in other forms the second pressure or product temperature. Obtaining includes obtaining the temperature of the product (eg, by the converter 216). In yet another form, obtaining the second pressure or temperature of the product can include obtaining the second pressure and obtaining the temperature of the product.

In one form, the method also includes, at a first temperature and a first temperature, by a processor (eg, processor 262) communicatively coupled to the cooling system 100 to maintain a predetermined cooling set point for the cooling system 100. Controlling a first valve (eg, valve 108) of the cooling system 100 based on the pressure of (block 412). In one form, the first valve can be an electronic stepper valve (eg, stepper valve 136) located between the condenser and the evaporator. In some forms, the method further includes calculating, by the processor, a current cooling level of the refrigerant exiting the condenser based on the first temperature and the first pressure. In these forms, controlling the first valve may include controlling the first valve based on the calculated current cooling level. In some forms, controlling the first valve includes opening or closing the first valve if the calculated current cooling level differs from a predetermined cooling setpoint. In one form, the method further comprises comparing the current cooling level of the refrigerant to a predetermined cooling set value, the predetermined cooling set value being the desired cooling level for the refrigerant as it exits the condenser. Controlling the first valve includes controlling the first valve based on the comparison.

In one aspect, the method also includes a processor for determining a second of the cooling system 100 based on the second pressure or the temperature of the product to optimize the capacity of the compressor (eg, compressor 124) of the cooling system 100. Controlling two valves (eg, valve 120) (block 416). In one form, the second valve can be a solenoid valve (eg, solenoid valve 150) located between the evaporator and the compressor. In some forms, the method further comprises comparing the resulting second pressure or product temperature to a predetermined second pressure or product temperature set point. In these forms, controlling the second valve of the cooling system may include controlling the second valve based on the comparison. In some forms, controlling the second valve, such as when the second valve is a solenoid valve, causes the second pressure or product temperature to be less than a predetermined second pressure or product temperature set point. When the solenoid valve is energized, and when the second pressure or product temperature is higher than a predetermined second pressure or product temperature set value, the solenoid valve is de-energized. In one form, the method further comprises suspending control of the first control valve when the solenoid valve is de-energized.

Based on the foregoing description, it should be understood that the devices, systems, and methods described herein facilitate a more efficient cooling system for cooling a product. This is based on obtaining data relating to the operation of the cooling system, controlling the first control valve based on the pressure and temperature of the refrigerant leaving the condenser of the cooling system, and on the pressure of the refrigerant leaving the evaporator. Or by controlling the second control valve based on the temperature of the product being cooled.

By controlling the first control valve in this manner, a predetermined cooling setpoint for the cooling system can be maintained. This ensures that the refrigerant leaving the condenser is sufficiently cooled so that the evaporator is flooded with liquid refrigerant and consequently saturated suction is supplied. Then, as it exits the evaporator, the refrigerant is at a lower superheat that would otherwise have been (in a traditional refrigeration system), which keeps the compressor motor cooler and the compressor volume higher. Improve efficiency. By controlling the second control valve in the manner outlined above, the capacity of the compressor can be controlled. Under low load conditions and/or low set point temperatures, compressor capacity can be reduced in a controlled manner. Such controlled reductions allow the product to cool closer to the freezing temperature, reduce the likelihood of ice on the evaporator and help maintain the desired evaporator conditions. However, when large volumes of product are to be cooled, or when the desired temperature of the product is higher, the capacity of the compressor can be increased in a controlled manner. In this way, product quality is improved and energy consumption is reduced without having to increase the duration of the cooling cycle (as in conventional cooling systems). Moreover, by controlling the capacity of the compressor in such a controlled manner, the compressor no longer has to be cycled on and off, and the stabilization of the temperature of the coolant for the condenser is made more stable. Ultimately, it will make it easier to maintain the desired product temperature.

Preferred embodiments of this disclosure have been described herein, including the best mode known to the inventors for carrying out this disclosure. While numerous examples are shown and described herein, those of skill in the art will readily appreciate that the details of various embodiments need not be mutually exclusive. Instead, one of ordinary skill in the art reading the teachings herein should be able to combine one or more features of one embodiment with one or more features of the remaining embodiments. Furthermore, it should be similarly understood that the described embodiments are merely representative and should not be taken as limiting the scope of the present disclosure. All methods described herein may be performed in any suitable order, unless explicitly stated otherwise or explicitly denied by context. Use of any and all examples or representative language (eg, “such as”) provided herein is intended only to make aspects of the exemplary embodiments of the present disclosure more apparent. However, the scope of the present disclosure is not limited in any way. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.

Claims (33)

A method of operating a cooling system comprising a condenser, an evaporator downstream of the condenser, a compressor downstream of the evaporator, and a refrigerant flowing through the cooling system to cool a product. ,
Obtaining a first temperature of the refrigerant downstream of the condenser and upstream of the evaporator from a first converter coupled to the cooling system;
Obtaining a first pressure of the refrigerant downstream of the condenser and upstream of the evaporator from a second converter connected to the cooling system;
Obtaining from a third converter connected to the cooling system a second pressure of the refrigerant downstream of the evaporator and upstream of the compressor or a temperature of the product to be cooled;
A processor communicatively coupled to the cooling system to maintain a predetermined cooling setpoint for the cooling system based on the first temperature and the first pressure based on the condenser and the evaporator. Based on the second pressure or the temperature of the product in order to control the opening of the first valve of the cooling system arranged between and to optimize the capacity of the compressor, Controlling a second valve of the cooling system coupled to the compressor;
Including the method. The method of claim 1, wherein controlling the first valve and controlling the second valve occur simultaneously. 3. The method according to claim 1 or claim 2, wherein obtaining the first temperature, the first pressure and the temperature or the second pressure of the product are performed simultaneously. The controlling the opening of the first valve includes controlling the opening of an electronic stepper valve arranged between the condenser and the evaporator, any one of claims 1 to 3. The method according to item 1. Further comprising calculating, by the processor, a current cooling level of the refrigerant exiting the condenser based on the first temperature and the first pressure, the opening of the first valve of the cooling system. Controlling the degree comprises controlling the opening of the first valve of the cooling system based on the calculated current cooling level. the method of. Controlling the opening degree of the first valve of the cooling system means controlling the opening degree of the first valve of the cooling system when the calculated cooling level is different from the predetermined cooling set value. 6. The method of claim 5, comprising increasing or decreasing. The processor further comprises comparing the calculated cooling level of the refrigerant to the predetermined cooling set point, the predetermined cooling set point being a desired cooling level of the refrigerant upon exiting the condenser. 6. The controlling of the opening of the first valve of the cooling system comprises controlling the opening of the first valve of the cooling system based on the comparison. the method of. The method of claim 1, wherein controlling the second valve comprises controlling an electromagnetic valve coupled to the compressor. Further comprising comparing the obtained second pressure or product temperature to a predetermined second pressure or product temperature setpoint, controlling the second valve of the cooling system based on the comparison. 9. The method of any one of claims 1-8, including opening or closing the second valve. Controlling the second valve energizes the solenoid valve when the second pressure or product temperature is less than the predetermined second pressure or product temperature set point, and the second pressure or 10. The method of claim 9, comprising deactivating the solenoid valve when the product temperature is greater than the predetermined second pressure or product temperature set point. The method of claim 10, further comprising suspending control of the first control valve when the solenoid valve is de-energized. Obtaining the second pressure or the temperature of the product includes obtaining the second pressure of the refrigerant downstream of the evaporator and upstream of the compressor, and controlling the second valve. 12. The method of any one of claims 1-11, comprising controlling the second valve based on the second pressure of the refrigerant. Obtaining the second pressure or the temperature of the product includes obtaining the temperature of the product, and controlling the second valve controls the second valve based on the temperature of the product. 12. A method according to any one of claims 1 to 11, comprising controlling. 14. The method of any one of claims 1-13, further comprising adjusting, by the processor, a speed of an electric fan coupled to the condenser based on the first pressure. 15. The method of any one of claims 1-14, further comprising causing the processor to generate a visual indicator when a failure condition is detected in the cooling system. A cooling system for cooling a product,
A condenser,
An evaporator arranged downstream of the condenser,
A compressor arranged downstream of the evaporator,
A first converter located immediately downstream of the condenser and configured to obtain a first temperature of the refrigerant downstream of the condenser and upstream of the evaporator;
A second converter located immediately downstream of the condenser and configured to obtain a first pressure of the refrigerant downstream of the condenser and upstream of the evaporator;
A third converter located immediately downstream of the evaporator and configured to obtain a second pressure of the refrigerant or a temperature of the product to be cooled downstream of the evaporator and upstream of the compressor; ,
A controller communicatively coupled to the first, second, and third converters, the controller configured to maintain the predetermined first cooling temperature and the predetermined first cooling temperature to maintain a predetermined cooling setpoint. Configured to control a first control valve located downstream of the condenser and upstream of the evaporator based on a first pressure, the controller for optimizing compressor capacity; And is configured to control a second control valve connected to the compressor based on the obtained second pressure or the temperature of the product.
Cooling system. 17. The cooling system of claim 16, wherein the first control valve comprises an electronic stepper valve configured to reduce the pressure of the refrigerant. 18. A cooling system according to claim 16 or claim 17, wherein the second control valve comprises a solenoid valve configured to load or unload the compressor. Further comprising a fan arranged to draw a cooling medium across the condenser, and a fan drive configured to control the speed of the fan, the controller providing the first pressure to the obtained first pressure. The cooling system according to claim 16, wherein the cooling system is configured to control the fan driving device based on the cooling system. 20. Any of claims 16-19, further comprising a portable device communicatively coupled to the controller, the portable device configured to allow a user to remotely monitor the cooling system. The cooling system according to item 1. The controller is configured to calculate a current cooling level of the refrigerant downstream of the condenser and upstream of the evaporator based on the obtained first temperature and first pressure. The cooling system according to any one of claims 16 to 20, wherein is configured to control the first valve of the cooling system based on the calculated cooling level. The controller is configured to compare the current cooling level of the refrigerant to the predetermined cooling set point, the predetermined cooling set point being a desired cooling level of the refrigerant upon exiting the condenser; 22. The cooling system of claim 21, wherein the controller is configured to control the first valve of the cooling system based on the comparison. The controller is configured to compare the obtained second pressure or temperature to a predetermined second pressure or temperature set point, and the controller controls the second valve of the cooling system based on the comparison. 23. A cooling system according to any one of claims 16-22, which is configured to control. The controller energizes the solenoid valve when the obtained second pressure or temperature is smaller than the predetermined second pressure or temperature set value, and the obtained second pressure or temperature is set to the predetermined second pressure or temperature. 24. The cooling system according to claim 23, which is configured to de-energize the solenoid valve when the pressure or temperature set value is greater than 2. A method of operating a cooling system comprising a condenser, an evaporator downstream of the condenser, a compressor downstream of the evaporator, and a refrigerant flowing through the cooling system to cool a product. ,
Obtaining a first temperature of the refrigerant downstream of the condenser and upstream of the evaporator from a first converter coupled to the cooling system;
Obtaining a first pressure of the refrigerant downstream of the condenser and upstream of the evaporator from a second converter connected to the cooling system;
Obtaining from a third converter connected to the cooling system a second pressure of the refrigerant downstream of the evaporator and upstream of the compressor or a temperature of the product to be cooled;
A processor communicatively coupled to the cooling system causes the condensation to cause the evaporator to overflow with liquid refrigerant based on the temperature and the pressure to maintain a predetermined cooling set point for the cooling system. Controlling the opening of an electronic stepper valve located between the evaporator and the evaporator, or by a processor communicatively coupled to the cooling system, to optimize the capacity of the compressor, Controlling a solenoid valve connected to the compressor based on the pressure or the temperature of the product;
Including the method. Controlling the opening of the electronic stepper valve of the cooling system further comprising calculating, by the processor, a current cooling level of the refrigerant exiting the condenser based on the temperature and the pressure; 26. The method of claim 25, comprising controlling the opening of the electronic stepper valve based on the calculated current cooling level. Controlling the opening of the electronic stepper valve of the cooling system controls the opening of the electronic stepper valve of the cooling system when the calculated current cooling level is different from the predetermined cooling set value. 27. The method of claim 26, comprising increasing or decreasing. The processor further comprises comparing the current cooling level of the refrigerant to the predetermined cooling set point, the predetermined cooling set point being a desired cooling level of the refrigerant upon exiting the condenser, 27. The method of claim 26, wherein controlling the opening of the electronic stepper valve of the cooling system comprises controlling the opening of the electronic stepper valve of the cooling system based on the comparison. 29. The method of any one of claims 25-28, further comprising: by the processor, adjusting the speed of an electric fan coupled to the condenser based on the temperature and/or pressure. Further comprising comparing the obtained second pressure or the temperature of the product to a predetermined second pressure or product temperature setpoint, wherein controlling the solenoid valve of the cooling system is based on the comparison. 30. A method according to any one of claims 25 to 29, comprising controlling the solenoid valve by means of a Controlling the solenoid valve energizes the solenoid valve when the pressure or temperature is lower than the predetermined pressure or temperature set value, and the solenoid valve when the pressure or temperature is higher than the predetermined pressure or temperature set value. 31. The method of claim 30, including de-energizing. Obtaining the second pressure of the refrigerant or the temperature of the product includes obtaining the second pressure of the refrigerant, and controlling the solenoid valve is based on the second pressure of the refrigerant. 32. The method of any one of claims 25-31, comprising controlling the solenoid valve by means of a Obtaining the second pressure of the refrigerant or the temperature of the product includes obtaining the temperature of the product, and controlling the solenoid valve controls the solenoid valve based on the temperature of the product. 32. The method of any one of claims 25-31, comprising: