DIGITAL CONTROLLER FOR REFRIGERATION WITH INTEGRATED ELECTRONIC EXPANSION VALVE DRIVE MODULE
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Utility models
- Current Assignee / Owner
- IVANIR ANTÔNIO GOBBI
- Filing Date
- 2023-07-12
- Publication Date
- 2026-06-12
AI Technical Summary
Current refrigeration systems face challenges in accurately controlling the degree of superheat due to limitations in mechanical thermostatic valves and the need for additional hardware modules, leading to increased costs and complexity, especially during power outages when external energy storage and solenoid valves are required.
A digital controller integrates all necessary functions, including electronic expansion valve control, energy storage, and power management within a single compact module, using a PID algorithm to adjust the stepper motor type electronic expansion valve, eliminating the need for external modules and solenoid valves, and ensuring the valve remains closed during power failures.
This solution simplifies installation, reduces costs and complexity, enhances control accuracy, and improves energy efficiency by integrating all necessary functions into a single module, ensuring reliable operation and energy savings by eliminating the need for external modules and solenoid valves.
Smart Images
Figure MX6228U0
Abstract
Description
DIGITAL CONTROLLER FOR REFRIGERATION WITH INTEGRATED ELECTRONIC EXPANSION VALVE DRIVE MODULE FIELD OF INVENTION
[0001] The present invention belongs to the field of digital electronic controllers, more specifically, digital control devices for refrigeration and degree of superheating of the refrigerant fluid with proportional integral derivative (PID) feedback. BACKGROUND OF THE INVENTION
[0002] The refrigeration cycle involves compression, condensation, expansion, and evaporation. In the expansion phase, current systems use mechanical thermostatic valves that require frequent adjustments and have low resolution in controlling the degree of refrigerant superheating.
[0003] The degree of superheat is defined as the saturated temperature differential, converted by the fluid pressure and the temperature at the suction point, traditionally at the end of the evaporator. Superheat must be high enough to prevent liquid refrigerant from returning to the compressor, otherwise it may break down. However, high superheat impairs the energy efficiency of the refrigeration system, combined with the increased physical size of the evaporator.
[0004] In this context, adequate control of the degree of superheating is essential for high efficiency of the refrigeration cycle, improving the coefficient of performance (COP = Refrigeration power / Compression power), however mechanical thermostatic valves have limited accuracy in this control.
[0005] This scenario encourages the use of electronic expansion valves, which can be pulse or stepper motor-driven. However, it is known from the literature that pulse valves have limited control accuracy, as their cyclical opening and closing movement results in water hammer. piping, restricting its use to cooling capacities of around 64kW, see<https: / / www.castel.it / wp-content / uploads / 2018 / 01 / Solenoid- expansion-valves.pdf> and <https: / / www.carel.eom / documents / 10191 / 0 / %2B4000009EN / e2e45752- 2e75-47d7-aed8-3a9865803c88>
[0006] To overcome this limitation, stepper motor-type expansion valves are used, which have superior performance in regulating the refrigerant fluid by enabling a more uniform and continuous variation.
[0007] Stepper motor-type electronic expansion valves traditionally require a dedicated drive device, increasing the cost of the final implementation and its volume, since in addition to the refrigeration controller, a drive device must be used.
[0008] One drawback of stepper motor-driven expansion valves is that they remain open even in the event of a power outage during operation. The traditional solution to this problem is to use batteries or modules external to the actuator to store enough electrical energy for automatic valve closure. This entails additional implementation costs and a further increase in volume, in addition to the complexity of electrical connections and mechanical fastening.
[0009] Another solution currently being developed is to block the flow of refrigerant using an additional solenoid valve. This way, in the event of a power outage, the solenoid closes, interrupting the flow. This solution requires additional components, resulting in higher implementation costs due to the need for more complex installation and material acquisition.
[0010] Among the equipment currently available on the Brazilian and international market is the RAC expansion valve kit, available at https: / / www.racbrasil.com / product-page / valvulaexpeletronica and manual available at https: / / drive.google.eom / file / d / 1654t09BGkdtMNZGxl1 lhWy_nownPWFxr / vie w, also the MPXPRO product from the company Garel, available at https: / / www.carel.com.br / product / mpxpro and manual available at https: / / www.carel.com.br / documents / 10191 / 0 / +0300055PT / 2ef2519c-4268- 42b1 -915a-db974c24814a?version=1 .5, as well as the EKE 1A from the company Danfoss, available at https: / / store.danfoss.com / br / pt_BR / Refrigera%C3%A7%C3%A3o-e-Ar- Condicionado / Controles-Eletr%C3%B4nicos / Controlador- electronic-superheating / Superheating-controller%2C-EKE-1A / p / 080G5300 do not fully meet the requirements of the product presented here, as they require additional hardware modules such as Human-Machine interfaces or extra drive and energy storage elements and modules.
[0011] In the “Beacon II refrigeration system”, equipment from Heatcraft Refrigeration Products, available at https: / / www.heatcraftrpd.com / PDF / Sales%20Brochures / SB-BEACONII.pdf, and referring to patent US5551248, in addition to the large volume, there is a need for a solenoid valve to close the refrigeration circuit in the event of a power outage.
[0012] Additionally, the VX950E Plus model, available at https: / / www.fullgauge.com.br / produto-vx-950-plus, is known as an example of a current product developed by the Applicant. A separate Human-Machine Interface (HMI) is required for the controller and an additional energy storage module is required.
[0013] In the case of the EKE 1 A product from Danfoss, it only has the function of driving electronic expansion valves of the stepper motor type, also being recognized in the market by the term Driver, referring to equipment that only drives the expansion valve or controls the degree of superheating.
[0014] Considering the RAC expansion valve kit equipment, its application is restricted to pulse-type expansion valves, also known as PWM, which limits its use to powers up to 32kW.
[0015] Stepper motor type electronic expansion valves reach powers in the order of 120kW for the so-called unipolar stepper motor, see < https: / / cdn.sanhuaeurope.co.Uk / new_content / static / uploads / files / products / en / ds-dpf-ts-s-en-r2007-1595836555. pdf#find-technical-info > and in the order of up to 2269kW for the so-called bipolar stepper motor, see < https: / / cdn.sanhuaeurope.co.Uk / new_content / static / uploads / files / products / en / ds-vpf-en-r2006-1591955358. pdf#find-technical-info > which gives them wide application in industrial and commercial refrigeration systems. This is combined with the fact that electronic expansion valves of the stepper motor type have lower electrical energy consumption when compared to the pulse type.
[0016] Regarding patent documents that reflect the state of the art for methods and apparatus for controlling the degree of superheating, the literature offers the North American patents US4067203, US4523435, US4617804, US4674292, US4787213, however, these apparatuses are not compact, are not equipped with the characteristics present here and do not integrate the same functionalities.
[0017] Other patent documents dealing with the subject are discussed below.
[0018] Patent US5551248 addresses the integrated control of a device's cooling system. The device receives data from temperature sensors, one of which is designed to measure evaporator superheat. The control device incrementally adjusts the position of the cooling system's expansion valve to regulate evaporator superheat and compressor discharge temperature.
[0019] Patent US7290402 describes a control system for an expansion valve and a control method for the expansion valve. In In one embodiment, the control system includes 1) a superheat error circuit configured to derive a superheat error for a fluid associated with the expansion valve, and 2) a valve position circuit associated with the superheat error circuit, configured to reposition the expansion valve proportionally based on both its current position and the superheat error. In patent US7290402, only the electronic valve control method is implemented; the other operating mechanisms of a refrigeration system are not covered.
[0020] In US patent 7788937, if the opening degree of an electronic expansion valve (14) is kept below a specific opening degree or if the superheat degree of a refrigerant in an evaporator (15) is kept above a certain superheat degree, the proportion of circulating refrigerant is considered insufficient. Thus, the volume of air delivered by a refrigerator fan (22) is reduced. In US patent 7788937, a method of controlling the electronic expansion valve (14) is implemented, accompanied by the description of the topology of the refrigeration system.
[0021] US patent 9151526 describes a vapor compression refrigeration cycle system that includes a compressor and an electronic expansion valve connected between the first and second refrigerant ports of a compressor. A controller for the electronic expansion valve is configured to control refrigerant flow through the expansion valve in response to a refrigerant superheat temperature. The controller is configured to execute a first control algorithm until a local maximum superheat temperature occurs, after which a second control algorithm is executed. In this US patent document, a control algorithm is implemented in a driver, controlling only the superheat of the electronic expansion valve; the approach focused on in the invention, which is a compact device, is not focused on.
[0022] All prior art documents cited above are directed to methods of controlling electronic expansion valves but always complying with a general configuration as illustrated in Figure 1 attached and described below in this report.
[0023] A system for controlling refrigeration and the degree of superheating of the refrigerant in prior-art refrigeration controllers is generally arranged in individual modules, as seen in Figure 1 attached to this report, where the control element (302) is external, connecting with wires to the driver (303) that drives the electronic expansion valve (301), which receives electrical energy from an external storage device (304) acting on the electronic valve (301). The prior-art system represented in Figure 1 has external modules, requiring several additional electrical connections, which contribute to a high potential for installation failures, extra cost due to the use of wires and cables, in addition to oversizing of electrical control panels and panels, making the installation complex and difficult to execute.
[0024] Therefore, the patent documents as well as catalogs and commercially available products, neither individually nor combined with each other, contemplate the configuration of the invention with an integrated module for controlling the superheating of an electronic expansion valve in a temperature controller. SUMMARY OF THE INVENTION
[0025] The digital refrigeration controller that is the object of the present invention integrates in the same compact configuration in a single module a digital refrigeration controller (100) performing the temperature control functions with scheduled defrost logic and refrigerant fluid collection (Pump-down).
[0026] The digital controller (100) for refrigeration, which comprises a system (200), is also equipped with control functions and logic for the compressor, fan, lamp and alarms, in addition to an energy saving function by scheduling and a real-time clock (209), a system (210) of actuation of electronic expansion valves of the stepper motor type, a system (212) to monitor the electrical current consumed by the electronic expansion valve (not shown), an emergency energy storage system (208) (to close the valve in the event of a power outage), a load control system (204), an emergency source (211) and a source detection and selection system (207).
[0027] The digital controller (100) for refrigeration therefore comprises a control system (200) capable of integrating the elements mentioned above into a compact system, changing the functional concept currently existing in similar products by allowing simplification of the electrical and mechanical installation process and reduction of inputs and raw materials. The connections of the Processing Unit (206) with the other elements of the system (200) enable a compact flow of control signals and measurement data, making them relevant to the purpose of the digital controller (100) for refrigeration.
[0028] Furthermore, the system of the invention is equipped with a feedback system with a PID control algorithm digitally implemented by the Processing Unit (206), which adjusts the opening of the electronic expansion valve of the stepper motor type according to the variables involved in the refrigeration process such as type of refrigerant fluid, temperature and pressure of the system.
[0029] Thus, an objective of the invention is a compact digital refrigeration controller, the system configuration being such as to integrate all the elements intended for the superheat control of the electronic expansion valve in a single module.
[0030] Another objective is a digital controller for refrigeration where the configuration of the electronic expansion valve superheat control system eliminates not only external modules for power supply when this is missing but also the addition of solenoid valves, the control system being contained in a single module.
[0031] Another objective is a digital controller for refrigeration where the configuration of the refrigerant superheat control system and the interaction of the respective functions allows for improved control of the refrigeration process.
[0032] Another objective is a digital refrigeration controller equipped with a control system that keeps the electronic expansion valve closed in the event of a power failure from the main source without the need for external power supply modules.
[0033] An additional objective is the creation of a refrigerant fluid collection function (Pump-down) with the aid of the sensor signal conditioning system (203) when measuring the refrigerant fluid pressure without the need for equipment external to the digital refrigeration controller. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figure 1 is a simplified schematic for a prior art refrigeration control system with individual, separate modules.
[0035] Figure 2 is a schematic illustration of the front of the refrigeration control equipment that uses the system of the invention.
[0036] Figure 3 is a schematic illustration of the rear of the refrigeration control equipment that uses the system of the invention.
[0037] Figure 4 is a simplified flowchart of the compact, single-module integrated refrigeration control system according to the invention. DETAILED DESCRIPTION OF THE INVENTION
[0038] According to the invention, the expression “integrated module” or “single module” means that all the elements that make up the control system of the present controller are contained in a single housing, as opposed to state-of-the-art controllers that employ several modules coupled through electrical, plastic and metallic connections and bonds.
[0039] Still according to the invention, the expression “electronic expansion valve with stepper motor type 11 includes both unipolar stepper motor and bipolar stepper motor.
[0040] Also according to the invention, in the present descriptive report, claims and summary, the expression “controller” is equivalent to the expressions “digital controller for refrigeration” or “digital controller” or even “controller for refrigeration”.
[0041] The invention therefore comprises a digital controller for refrigeration where, unlike state-of-the-art controllers that comprise several modules, the control of the superheating of the electronic expansion valve is carried out by a system contained in a single module.
[0042] In the following the invention will be described with reference to the attached Figures.
[0043] Thus, Figure 2 shows the front view of the controller (100) with the elements of the Human-Machine interface (205) (see Figure 4), namely, the key (101) for entering the so-called quick access menu, where a set of parameters that are easy for the user to access is available. By pressing the key (101) it is possible to navigate through the quick access menu and by pressing the key (102) it is possible to select the desired menu option, while the keys (103) and (104) allow the increment and decrement of the value of the parameter displayed on the front display. The LED (110) indicates the status of the compressor output (132), the LED (109) indicates the status of the fan output (133), the LED (108) indicates the status of the defrost output (134), the LED (107) indicates the status of the lamp (135) or auxiliary (135) output, the LED (106) indicates the modulation process of the stepper motor type electronic expansion valve and the LED (105) indicates the scale used by the controller in degrees Celsius or Fahrenheit.
[0044] Figure 3 shows the rear view of the digital controller (100) for refrigeration where the connector with numbers from (111) to (130) is intended for the connections of sensors, power supply, communication serial and connection to the electronic expansion valve of the stepper motor type. The connector with numbers from (131) to (135) is intended for power connections.
[0045] The sensor for the current temperature measured in the refrigeration process, referred to as S1, is connected between (111) and (112), the sensor for the current temperature measured in the evaporator, referred to as S2, is connected between (113) and (114), the sensor for the current temperature measured at the suction point in the compressor, referred to as S3, is connected between (115) and (116), and the sensor for the suction pressure of the refrigerant in the compressor, referred to as P1, is connected between (123) and (124). These sensors are those mentioned in element (203), Sensor signal conditioning system of Figure 4.
[0046] The power supply of the digital controller (100) for refrigeration is carried out between (121) and (122), between (117) and (118) a digital input is present, and between (119) and (120) there is serial communication.
[0047] The stepper motor type electronic expansion valve (not shown) is connected between (126) to (130).
[0048] Still in Figure 3, we can see the compressor output (132), the fan output (133), the defrost output (134), the lamp output (135) or auxiliary (135) and in (131) the common of the outputs.
[0049] Figure 4 is a flowchart of the internal elements of the refrigeration control system (200) and the degree of superheating of the refrigerant fluid and their logical and functional interactions to create the digital controller (100) for refrigeration.
[0050] In the system (200), a Human-Machine Interface (205) is equipped with access keys for navigation in the controller programming and increment / decrement of the parameters programmed in the internal non-volatile memory, as well as an LED display for indicating the process quantities and messages to the user. These elements were described with reference to Figure 2.
[0051] The elements that make up the system (200) of the digital controller (100) for refrigeration of the invention are commercially available and will be described in detail below in this report.
[0052] The refrigerant fluid superheat control system (200) of the digital refrigeration controller (100) comprises, in a single module, the following elements:
[0053] A main source (201) to provide adequate voltage levels to the internal elements of the system (200), connected between (121) and (122) (see Figure 3) with a voltage of 12V in direct current. A source (201) useful for the purposes of the invention is constituted by voltage regulating semiconductor integrated circuits, establishing adequate levels of electrical potential for polarization of the elements of the system (200).
[0054] A Serial Communication interface (202) using RS485 serial communication standard for interfacing and remote operation control. This type of interface is useful for the purposes of the invention as it allows receiving operating commands, receiving recipes and scheduling events, reading and writing function parameters saved in non-volatile electronic memory, and monitoring measurements of the Sensor Signal Conditioning System (203).
[0055] A Sensor Signal Conditioning System (203) for conditioning sensor signals to a standard compatible with the electrical standard of the Processing Unit (206). A Sensor Signal Conditioning System (203) useful for the purposes of the invention is constituted by an arrangement of resistors and capacitors arranged in the form of signal attenuation and filtering networks, conditioning sensor signals at electrical levels suitable for the operation of the Processing Unit (206).
[0056] A Load Control system (204) for maintaining the appropriate electrical load level in the Emergency Power storage system (208). The system (204) is useful for the purposes of the invention because it ensures through the use of semiconductor transistors a minimum level of stored energy, in addition to protection against overloads, ensuring safety.
[0057] A Human-Machine interface (205) equipped with keys and an LED display. The interface (205) is useful for the purposes of the invention by allowing the user easy access to the functions menu and instant viewing of the refrigeration process measurements.
[0058] A processing unit (206), also called an embedded processing unit, which manages the entire controller (100). The unit (206) is useful for the purposes of the invention because it is capable of executing pre-programmed instructions stored in non-volatile electronic memory, enabling the creation of control, supervision and data communication algorithms.
[0059] A Source Detection and Selection System (207) that allows the digital controller (100) for refrigeration to continue operating in the event of a power outage. A Source Detection and Selection System (207) useful for the purposes of the invention consists of an electronic voltage comparator to signal the occurrence of a power outage in the main source (201), ensuring rapid switching to the emergency source (211).
[0060] An Emergency Energy Storage System (208) capable of maintaining sufficient electrical energy to close the electronic valve (not shown) in the event of a power outage or failure. An Emergency Energy Storage System (208) useful for the purposes of the invention is comprised of a solid-state element with electrical properties of an electrostatic energy store.
[0061] A Real Time Clock (209) capable of synchronizing the digital controller (100) for refrigeration. A Real Time Clock (209) useful for the purposes of the invention is constituted by a specific integrated circuit and by a data interface with the processing Unit (206), thus allowing the creation of scheduling of defrost events and entry into economic mode.
[0062] A Stepper Motor Type Electronic Expansion Valve Drive System (210) that allows the digital controller (100) for refrigeration to control the degree of superheat. A Stepper Motor Type Electronic Expansion Valve Drive System (210) useful for the purposes of the invention is constituted by semiconductor static switches and allows the digital controller (100) for refrigeration to control the refrigeration and degree of superheat functions at the same time.
[0063] An Emergency Source (211) capable of maintaining the operation of the digital controller (100) for refrigeration until the complete closure of the electronic valve (not shown). An Emergency Source (211) useful for the purposes of the invention consists of a solid-state switching converter of the voltage boost type and ensures the operation of the digital controller (100) for refrigeration in the moments in which an emergency closure of the expansion valve (not shown) is necessary due to a lack of electrical energy.
[0064] A Current Monitor (212) provides feedback to the digital controller (100) for refrigeration on the operating status of the expansion valve (not shown). A Current Monitor (212) is useful for the purposes of the invention because it provides feedback, or feedback, which allows the digital controller (100) for refrigeration to know the operating status of the expansion valve (not shown), improving the operational safety of the refrigeration process, since operating alarms can be issued.
[0065] The operation of the digital refrigeration controller (100) system (200) for controlling the superheating of the refrigerant fluid will be described below in this report.
[0066] The onboard Processing Unit (206) communicates with the serial communication Interface (202), with the Human-Machine Interface (205), with the Real Time Clock (209) and with the Electronic Expansion Valve Drive System (210) of the stepper motor type.
[0067] The communication of the embedded processing unit (206) with the Real Time Clock (209) allows the creation of an electronic schedule structure for defrosting in addition to the schedule of the so-called economic mode, referring to scheduled change events in the set-point for adjusting the temperature of the refrigeration process during periods of low demand, enabling energy savings. The energy savings obtained by the system of the invention are superior to those of prior art systems, since the energy consumption of the additional modules has been eliminated.
[0068] The embedded Processing Unit (206) also communicates with the Serial Communication Interface (202), and with the Signal Conditioning System (203) of the process Sensors. These sensors were mentioned in the description of Figure 3, being referred to as S1 for the current temperature measured in the refrigeration process, S2 for the current temperature measured in the evaporator, S3 for the current temperature measured at the suction point in the compressor, and P1 for the suction pressure of the refrigerant in the compressor. These sensors generate feedback signals for the PID algorithm, digitally implemented in the Unit (206) which, through its connections with the Serial Communication Interface (202), the Human-Machine Interface (205), the Clock (209) and the System (210), ensures responsive control since its direct connection is not subject to network traffic.
[0069] According to the invention, the sensor signal conditioning system (203) when measuring refrigerant pressure allows for the creation of a refrigerant pump-down function. In prior art systems, this function is usually performed by equipment external to the controller, adding bulk to the installation and cost in acquiring additional equipment. Furthermore, adjusting this function becomes more complex and impractical, as the additional equipment traditionally does not communicate with the process controller, requiring manual adjustment subject to human error.
[0070] According to the invention, the pressure measurement, when converted to saturated temperature, allows for the creation of low evaporation temperature (LOP) and high evaporation temperature (MOP) protection functions. These protections operate in extreme operating situations, typically during transient events when high-intensity thermal loads are required. Such situations can compromise the compressor's operational lifespan in the refrigeration system, as they require greater electromechanical effort during transient conditions.
[0071] The embedded processing unit (206) generates digital switching signals in frequency and amplitude that, when applied to the stepper motor-type Electronic Expansion Valve Drive System (210), command the modulation necessary to maintain the superheating level. Advantageously, in the invention, the integration between said elements (206) and (210) makes the control response faster by facilitating the exchange of measurement information and control signals at high data rates, as they are in the same module, eliminating traffic conflict in networks.
[0072] Furthermore, the aforementioned Processing Unit (206), together with the current monitor (212), allows obtaining the valve status, making it possible to determine whether it is operational or not. Advantageously, this functionality increases the safety of the refrigeration plant's operation, as it generates operating alarms for the refrigeration plant's technical managers, reducing the possibility of equipment damage. This important functionality is neither described nor suggested in the prior art systems.
[0073] As can be seen in the diagram in Figure 4, a Source Detection and Selection System (207) constantly monitors the electrical voltage supplied by the Main Source (201); if it fails due to lack of electrical energy, the emergency Source (211) is activated, receiving the energy stored in the Emergency Energy Storage System (208).
[0074] The Emergency Energy Storage System (208) is managed by the Load Control System (204), ensuring that the stored energy will be sufficient for the need for emergency closing of the electronic expansion valve of the stepper motor type in the event of a power outage, configuring a competitive advantage of the present invention in relation to the state of the art, since the need for an external module to supply power in the event of a power outage is eliminated.
[0075] The logical and physical connection between the main Source (201), the Load Control (204), the Processing Unit (206), the Source Detection and Selection System (207), the Emergency Energy Storage System (208), the Stepper Motor-type Electronic Expansion Valve Actuation System (210), the Emergency Source (211) and the System (200) Current Monitor (212) make the digital controller (100) for refrigeration capable of withstanding power outage events and still guaranteeing emergency closure of the Stepper Motor-type Electronic Expansion (not shown).
[0076] The interaction between the various elements of the system (200) will be described below, when in operation, to act in controlling the overheating of the refrigerant fluid when a power outage is detected.
[0077] The system (200), when a power outage is detected by the Source Detection and Selection System (207): a) said Source Detection and Selection System (207) generates a signal to the Processing Unit (206) also switching the Emergency Source (211); b) the signal received from said Source Detection and Selection System (207) by the Processing Unit (206) initiates the closing of the expansion valve through the Electronic Expansion Valve Actuation System (210) where the Current Monitor (212) implements the Status feedback; c) the Emergency Source (211) switched by the Source Detection and Selection System (207) receives energy stored in the Emergency Energy Storage System (208) previously charged by the Load Control System (204); and d) the Source Detection and Selection System (207) implements the switching of the Emergency Source (211), while the interaction between the main power Source (201), the Load Control System (204) and the Emergency Energy Storage System (208) ensures that the Emergency Source (211) functions when needed.
[0078] The preceding description relating to the digital controller (100) for refrigeration and the relationships between the various elements comprising the on-board control system (200) is further detailed below: a) A Processing Unit (206) for managing the refrigeration controller (100) through the execution of pre-programmed instructions stored in non-volatile electronic memory, said Unit being connected to the following elements: a1) a Serial Communication Interface (202) for interfacing and remote control of operation; a2) a Sensor Signal Conditioning System (203) for conditioning the sensor signals to a standard compatible with the electrical standard of said Processing Unit (206); a3) a Load Control system (204) for maintaining an adequate electrical load level in the Emergency Energy Storage System (208).a4) a Human-Machine Interface (205); a5) a Source Detection and Selection System (207) so that the refrigeration controller (100) continues to operate even in the event of a power outage;. a6) an Emergency Energy Storage System (208) to maintain sufficient electrical energy for closing the electronic valve in the event of a power failure or outage; a7) a Real Time Clock (209) to create a schedule for defrost events and entry into economic mode; and a8) a Stepper Motor Type Electronic Expansion Valve Actuation System (210); b) A main power source (201), said source (201) being connected to the Load Control System (204), the Source Detection and Selection System (207) and the Sensor Signal Conditioning System (203); c) An Emergency Source (211) to maintain the operation of the refrigeration controller (100) until the electronic valve is completely closed, and connected to the Source Detection and Selection System (207) and the Emergency Energy Storage System (208);and d) A Current Monitor (212) to provide feedback to said refrigeration controller (100) on the operating status of the electronic expansion valve.;
[0079] Additionally, the digital controller (100) for refrigeration of the invention can be configured to operate only in the Driver function, where it disables the refrigeration functions and logic and acts only on the actuation of the electronic expansion valve of the stepper motor type and control of the degree of superheating with PID feedback.
[0080] Furthermore, the digital controller (100) for refrigeration is equipped with integrated protection functions to protect the compressor from low superheat (LoSH), low evaporating temperature (LOP) and high evaporating temperature (MOP) events, adding parameters to establish alarm conditions and reactions to them. This low superheat (LoSH) protection acts in transient events with large change in thermal load, acting to prevent the return of refrigerant in liquid state to the compressor.
[0081] Thus, the technological innovation presented is an advance in relation to the state of the art as it consists of a complete and integrated digital controller (100) for refrigeration for mounting on a panel door or electrical control panel, facilitating the installation and operation of industrial and commercial refrigeration plants and processes by integrating a large set of systems in a single compact controller, installed in a single module.
[0082] Such systems are currently arranged in individual modules, as seen schematically in the block diagram of Figure 1, where the control element (302) is external, connecting with wires to the driver (303) that drives the electronic expansion valve (301), which receives electrical energy from an external storage device (304) acting on the electronic valve (301). These prior art systems make the process of adjusting and parameterizing functions difficult, since their elements are physically separated, with no logical communication between them. In this sense, the invention brings new operational and competitive advantages by enabling the processing unit (206) to control the various functions mentioned above at the same time that the interaction between the elements of the system (200) integrated in the digital controller (100) for refrigeration results in a reduction in installation complexity.
[0083] Thus, although the elements that make up the arrangement of the control system (200) of the digital controller (100) for refrigeration are commercially available, the present invention is not only novel, as similar equipment in a single module to perform the desired control function is not known, but also inventive, as it incorporates logical communication between the various elements in order to obtain results not described and not foreseen in the state of the art, facilitating the process of adjustment and parameterization of the functions, while at the same time reducing installation complexity.
[0084] Advantageously, the invention, by considering the reduction of inputs and raw materials such as plastics, also extending to metals in the installation and production stages, objectively reduces such needs in accordance with current environmental concerns. This concern is fundamental today, given that Brazil is the 4th Q country that produces the most plastic waste, see<https: / / www.wwf.org.br / 770222 / Brasil-e-o-4-pais- do-mundo-que-mais-gera-lixo-plastico> .
Claims
CLAIMS 1. Digital controller for refrigeration with integrated electronic expansion valve drive module, said digital controller (100) being equipped with non-volatile memory and characterized by having an embedded system (200) comprising the following elements: a) A Processing Unit (206) for managing said digital controller (100) for refrigeration through the execution of pre-programmed instructions stored in non-volatile electronic memory, said Unit being connected to the following elements: a1) a Serial Communication Interface (202) for interfacing and remote operation control; a2) a Sensor Signal Conditioning System (203) to condition the sensor signals to a standard compatible with the electrical standard of said Processing Unit (206); a3) a Load Control System (204) to maintain an adequate electrical load level in the Emergency Energy Storage System (208).a4) a Human-Machine Interface (205); a5) a Source Detection and Selection System (207) so that the refrigeration controller (100) continues to operate even in the event of a power outage; a6) an Emergency Energy Storage System (208) to maintain sufficient electrical power for closing the electronic valve in case of a power failure or outage; a7) a Real-Time Clock (209) for creating a schedule of defrosting events and entering economy mode; and a8) a Stepper Motor type Electronic Expansion Valve Actuation System (210); b) A main power source (201), said source (201) being connected to the Load Control System (204), the Source Detection and Selection System (207), and the Sensor Signal Conditioning System (203); c) An Emergency Source (211) to maintain the operation of the refrigeration controller (100) until the complete closure of the electronic valve, and connected to the Source Detection and Selection System (207) and the Emergency Energy Storage System (208); d) A Current Monitor (212) to provide feedback to said refrigeration controller (100) on the operating status of the electronic expansion valve. Digital controller for refrigeration according to claim 1, characterized in that the sensor signal conditioning system (203) creates a refrigerant recovery (Pumpdown) function.Digital controller for refrigeration according to claim 1, characterized in that the Source Detection and Selection System (207) is additionally connected to the Main Power Source (201), to the Electronic Stepper Motor Type Expansion Valve Actuation System (210), to the Emergency Power Source (211) and to the Current Monitor (212). Digital controller for refrigeration according to claim 1, characterized in that, during operation, when a power failure is detected by the Source Detection and Selection System (207): a) said System (207) generates a signal to the Processing Unit (206) also switching the Emergency Power Source (211); b) the signal received from said Source Detection and Selection System (207) by the Processing Unit (206) initiates the closing of the Electronic Stepper Motor Type Expansion Valve by means of the Electronic Expansion Valve Actuation System (210). of the Stepper Motor type where the Current Monitor (212) implements Status feedback; c) the Emergency Source (211) switched by the Source Detection and Selection System (207) receives energy stored in the Emergency Energy Storage System (208) previously loaded by the Load Control System (204); d) the Source Detection and Selection System (207) implements the switching of the Emergency Source (211), while the interaction between the main power Source (201), the Load Control System (204) and the Emergency Energy Storage System (208) ensures that the Emergency Source (211) operates when needed. Digital controller for refrigeration according to claim 1, characterized in that the rear external part of said integrated module comprises sensor S1 connected between (111) and (112), sensor S2 connected between (113) and (114), sensor S3 connected between (115) and (116), and sensor P1 connected between (123) and (124).Digital controller for refrigeration according to claim 5, characterized in that the external rear part of said module further comprises the power supply of the digital controller (100), carried out between (121) and (122), between (117) and (118) a digital input is present, and between (119) and (120) is the input for the serial communication interface (202). Digital controller for refrigeration according to claim 5, characterized in that the external rear part of said module further comprises a connection between (126) and (130) for the Electronic Expansion Valve of the Stepper Motor type. Digital controller for refrigeration according to claim 5, characterized in that the external rear part of said integrated module further comprises the compressor output (132), the output of the... fan (133), defrost output (134), lamp output (135) or auxiliary (135) and in (131) the common of the outputs. Digital controller for refrigeration according to claim 1, characterized by operating in Driver function.