Method for operating an object of a laboratory device cooled by means of a flammable refrigerant

Abstract

A method for operating an object of a laboratory device (1; 101) cooled by means of a flammable refrigerant is proposed, the method comprising: ventilating an interior (3) of the cooled laboratory device (1; 101) by means of a fan (2), wherein the control of the fan (2) is performed by a first control device (ST1) for a first time period; checking whether the ventilation was successful by means of a first predefined criterion; passing the control of the fan (2) to a second control device (ST2) if the ventilation for the first time period was successful; checking whether the second control device (ST2) successfully controls the fan (2) by means of a second predefined criterion; activating a power supply for at least one further device (5, 7) of the cooled laboratory device (1; 101) to be supplied with power if the fan (2) is successfully controlled by the second control device (ST2). A corresponding object of a laboratory device is also proposed.

Description

Technical Field

[0001] This invention relates to a method for operating an object of laboratory equipment cooled by a flammable refrigerant, and to an object relating to such laboratory equipment. Specifically, the object may refer to a laboratory apparatus or laboratory instrument. Background Technology

[0002] Cooled objects in laboratory equipment must meet various safety requirements. For example, DIN EN 61010-2-011 specifies safety requirements for electrical measurement, control, regulation, and laboratory equipment. In particular, it should be ensured that the design and construction of refrigeration equipment provides adequate protection for users, bystanders, trained service personnel, and the surrounding area from the specific hazards that may arise from the refrigeration system.

[0003] The DIN EN 378 standard considers the life cycle of refrigeration facilities, particularly regarding facility / equipment safety, but also takes into account factors such as the area where the facility is located, refrigerant limits, and personnel protection in cold spaces. This standard specifically addresses the flammability ratings of refrigerants as defined in ISO 817: 1 (no flame propagation), 2L (low flammability), 2 (flammable), and 3 (highly flammable). Examples of refrigerants include: propane, (iso)butane (flammability rating 3); R152a (flammability rating 2); R1234yf (flammability rating 2L); R410A, R22 (flammability rating 1).

[0004] However, highly flammable hydrocarbons, particularly propane and (iso)butane, have favorable environmental properties. For example, the aforementioned refrigerants have an ozone depletion potential (“ODP”) of 0 and a global warming potential (“GWP”) or carbon dioxide equivalent of only 3.

[0005] In modern cooling laboratory equipment, the use of refrigerants with good environmental properties is desirable. Regarding the aforementioned refrigerants propane and (iso)butane, additional safety precautions are necessary. A safe environment inside the machine is particularly important. Specifically, the environment must remain safe even in the event of flammable refrigerant releases, such as in the event of leaks, damage, or malfunctions. Summary of the Invention

[0006] This invention addresses the technical problem of improving the operational safety of laboratory equipment cooled by flammable refrigerants. Another technical problem upon which this invention is based is achieving particularly fail-safe and reliable fan control, and identifying fan defects particularly early and reliably.

[0007] According to the basic idea of ​​the invention, the interior of the cooled object of the laboratory equipment (hereinafter referred to as the "cooled laboratory equipment") is first ventilated by a fan after being turned on. This fan is controlled by a first control device, which may in particular be a hardware-based control device. This ventilation process may in particular have a defined minimum duration. A first test operation of the fan (e.g., by means of which the fan's correct functionality is checked) and / or a first safety operation (e.g., by means of which the refrigerant can be removed from the interior by the fan) can be performed in this manner. The first control device and / or the fan may have a power supply that is independent of other power supplies to other components or devices of the cooled laboratory equipment and / or may be activated independently of other power supplies and / or may be designed separately. For example, the power supply may in particular have a separate cable strand.

[0008] In particular, the first control device may have a particularly simple structure. "Hardware-based" can especially mean that all control commands are pre-given, defined, and / or implemented on the hardware side of the first control device, i.e., for example, by using electrical or electronic components. "Hardware-based" may alternatively or additionally indicate that the function of the first control device can be implemented by discretely constructed circuits and / or that the function of the first control device can be implemented using standard components (particularly electrical or electronic standard components). In particular, the first control device may be a control device without a data interface and / or without data memory. For example, the first control device may also have only ROM memory. Regarding the first control device, "hardware-based" may alternatively or additionally indicate that the first control device has no software or firmware. Regarding the first control device, "hardware-based" may alternatively or additionally indicate that the first control device does not have a chip or memory for storing software or firmware. Regarding the first control device, "hardware-based" may alternatively or additionally indicate that the first control device does not have control algorithms or control commands stored on a chip or in memory.

[0009] The first control device may in particular have an on / off switch, or in a particularly simple embodiment, consist of an on / off switch that can be connected to the on / off state of the laboratory equipment. If, for example, the on / off switch of the laboratory equipment is turned on, the first control device may also automatically turn on, causing the fan to ventilate the interior.

[0010] Ventilation can be used for testing fans or for removing refrigerant from within. Other (or all other) devices in the laboratory equipment that require power should at least remain switched off.

[0011] -Until ventilation is automatically determined to be successful and / or

[0012] - Until the fan control has been transmitted to the second control unit and the second control unit is automatically determined to have successfully controlled the fan.

[0013] In particular, this avoids the risk of sparks forming inside the cooling laboratory equipment, which could ignite flammable refrigerant if present.

[0014] The second control device can be, in particular, a software- and / or firmware-based control device. The second control device may, for example, have a memory (e.g., a rewritable memory chip or hard disk) containing stored program commands and / or a measurement sensor system (e.g., a temperature sensor or a probe for measuring refrigerant concentration) and / or, for example, enable variable speed control of the fan by means of pulse width modulation and appropriate means, such as by means of stored characteristic curves, which can, for example, connect values ​​from the temperature sensor or probe to the rotational speed. If the second control device is firmware-based, the program instructions can be stored, in particular, in ROM memory. If the second control device is software-based, the program instructions can be stored, in particular, in read-write memory. The second control device can be configured to control the fan even during normal operation of the cooling laboratory equipment. Normal operation of the cooling laboratory equipment can be performed in conjunction with or after the method according to the invention.

[0015] Regarding the second control device, "software-based" may alternatively or additionally indicate that the second control device has software. Regarding the second control device, "software-based" may alternatively or additionally indicate that the second control device has a chip or memory storing the software. Regarding the second control device, "software-based" may alternatively or additionally indicate that the second control device has control algorithms or control commands stored on the chip or in the memory (particularly in read / write memory).

[0016] Regarding the second control device, "firmware-based" may alternatively or additionally indicate that the second control device has firmware. Regarding the second control device, "firmware-based" may alternatively or additionally indicate that the second control device has a chip or memory storing the firmware. Regarding the second control device, "firmware-based" may alternatively or additionally indicate that the second control device has control algorithms or control commands stored on the chip or in the memory (particularly in read-only memory).

[0017] The second control device can be one in which safety and / or reliability and / or proper functioning must first be demonstrated through approval or certification methods. Such methods can be very time-consuming and expensive. Furthermore, even small subsequent changes can require a significant amount of work. For example, even small subsequent changes may require their own approval or certification methods.

[0018] The second control device can typically be connected to the equipment-side control device, which controls the cooling laboratory equipment (and particularly the fans of the cooling laboratory equipment) during operation. The second control device can be the equipment-side control device or a part of it, or it can be connected to or integrated into it. However, it is not excluded that the second control device can be a separate control device from the equipment-side control device.

[0019] In particular, it was proposed

[0020] A method for operating an object in laboratory equipment cooled by a flammable refrigerant, comprising:

[0021] - Ventilation is provided inside the cooled object of the laboratory equipment by means of a fan, wherein the fan is controlled by a first control device during a first time period;

[0022] - Check if ventilation is successful using the first predefined standard;

[0023] -If ventilation is successful in the first time period, the control of the fan is transferred to the second control device;

[0024] - Use a second predefined standard to check whether the second control device successfully controls the fan;

[0025] - If the fan is successfully controlled by the second control device, the power supply to at least one other device to be supplied with electricity for cooling the laboratory equipment is activated.

[0026] Flammable refrigerants may in particular be refrigerants with flammability ratings of 2L, 2, or 3. Specifically, flammable refrigerants may be, for example, propane, butane, or isobutane (flammability rating 3). Other refrigerants, including those with flammability ratings of 2L and 2, are not excluded.

[0027] Cooling laboratory equipment can be an object that has a cooling function during operation, such as for samples. Cooling laboratory equipment can particularly have a refrigeration circuit in which a refrigerant is used. The refrigeration circuit can particularly have an evaporator, a compressor (e.g., a compressor unit), a liquefier (e.g., a condenser unit), and / or a throttling mechanism. Furthermore, the refrigeration circuit can particularly have connecting elements, seals, and / or piping. Additional devices to be powered can be, for example, components of the refrigeration circuit, such as a compressor, which can be embodied as an electric compressor, or a motor, such as (e.g., a centrifuge rotor). For example, cooling laboratory equipment can particularly be a laboratory centrifuge or a laboratory refrigerator. Other equipment and equipment types are not excluded.

[0028] Internal ventilation can specifically refer to internal airflow, particularly to completely or substantially remove any potentially flammable refrigerant from the interior. Flammable refrigerant may be present inside the interior in cases where, for example, a leak or lack of sealing occurs in the refrigeration circuit or its components, and thus flammable refrigerant has partially entered the interior.

[0029] The interior can be, for example, the interior of a housing or housing portion, or the interior below, near, or within the cover or inner or outer wall of the cooling laboratory equipment. For example, the interior may contain at least one or all components of the refrigeration circuit and / or may be adjacent to and / or positioned close to at least one component of the refrigeration circuit. The interior may also contain other components of the cooling laboratory equipment, such as electronic devices or motors. The interior may, for example, have at least one outward opening, preferably multiple openings, to ensure air exchange with the interior and exterior spaces, especially the exterior area and / or the surrounding environment.

[0030] The fan may be or has a ventilator. For example, the fan may be or has an axial fan or axial blower. In particular, the fan speed can be controlled, making different fan speeds possible, for example, by means of pulse width modulation (the term pulse width modulation can be understood as a synonym for the term pulse width modulation). For example, the fan may be located at an opening leading to the outside. The fan may be preferably integrated into the cooling laboratory equipment. It is not excluded that the fan may be embodied as an external unit.

[0031] In a simplified embodiment, fan control during a first time period can mean that the fan is turned on and remains on during that first time period. For example, the fan can be controlled to reach and / or not fall below a first predefined fan speed during the first time period. The fan may have a speed determination device (e.g., a Hall sensor) for determining the tachometer signal and / or the number of revolutions per unit time, or it may be connected to such a speed determination device.

[0032] For example, the first time period can be a predetermined time period, such as 3-20 seconds, preferably 5-15 seconds, and particularly preferably 8-10 seconds. The first time period can especially depend on the internal volume and volumetric flow of the fan used. The counting or measurement of the first time period can be completed automatically by means of a timing device including a timer. The counting or measurement of the first time period can be implemented alternatively or additionally by means of an analog or digital timer. In a simple implementation, the counting or measurement of the first time period can begin when the fan is turned on or running. Alternatively or additionally, the counting or measurement, especially the start of the counting or measurement, can be associated with conditions. For example, the first time period or time measurement can begin immediately after the fan is turned on and reaches a certain fan speed.

[0033] For example, the first control device may have an on / off switch. For instance, the on / off switch can be operated when the laboratory equipment is turned on. The on / off switch may be connected to or be the on / off switch of the laboratory equipment. Performing ventilation may be part of the laboratory instrument's start-up process. Ventilation may occur particularly before another device to be powered (or multiple or all other devices to be powered) cooling the laboratory equipment is turned on or powered. Ventilation may particularly be automatic. This may particularly mean that no human user is required to perform the ventilation action. If necessary, a human user may initiate the start-up process of the cooling laboratory equipment, for example, by operating the laboratory equipment's on / off switch.

[0034] In particular, the first control device can have a particularly simple structure. Specifically, it can be hardware-based. Refer to the explanation above. The first control device can especially have simple, hardware-implemented control logic that enables the fan to operate at a specific fan speed, which can be the fan's maximum speed or a specific fan speed. More complex embodiments of the first control device are not excluded. The first control device and / or the fan can have separate and / or independent and / or spatially separate power supplies from other power supplies of other equipment in the cooling laboratory equipment (e.g., this can be cables, connectors, and / or electrical wiring). The power supply can have, for example, separate lines and / or separate external connections on the cooling laboratory equipment or separate cable strands or connections within the cooling laboratory equipment. The power supply can be connected independently of other power supplies.

[0035] If, during ventilation, only the first control unit and / or fan are initially turned on when the cooling laboratory equipment is activated, and other devices within the equipment are (not yet) powered, the risk of spark formation is reduced, especially inside the cooling laboratory equipment. Therefore, if flammable refrigerant is present, it can be removed first through ventilation. Other devices that might generate sparks from the power supply should not be activated until the flammable refrigerant is no longer present.

[0036] In particular, a checking device can be used to check a first predetermined criterion. In a simple embodiment, the checking device may, for example, have a threshold switch. This threshold switch may have a capacitor that is charged when a specific fan speed is reached and / or an alternative timer or timer. Once, for example, after a first time period, a specific charge value of the capacitor is reached and thus a specific voltage value is reached at the capacitor, the presence of the voltage value can be used as a signal that the check by means of the first predefined criterion is successful. On the other hand, if the specific fan speed is not reached, the capacitor can be discharged again. Only when the specific fan speed is reached within a specific time period (e.g., the first time period) can the voltage value be high enough to be considered that the first predefined criterion has been successfully met. In a more complex embodiment, the checking device may alternatively or additionally have checking logic, for example, implemented by means of a computing device (e.g., a processor) and corresponding commands, control rules, and / or features. The checking device may also have a timer.

[0037] Alternatively or additionally, the testing device may have, for example, an AC voltage amplifier that charges a capacitor with energy when there is an edge change in the tachometer signal (corresponding to the fan speed signal). If the frequency of the edge change (and therefore the fan speed) is high enough (i.e., equal to or higher than a given fan speed), the power reaching the capacitor is greater than the power drawn from the capacitor. Alternatively or additionally, the testing device may also have, for example, an integrated circuit, such as a retrievable monostable multivibrator or a monostable trigger.

[0038] The monitoring device may alternatively or additionally include, for example, a counter or counter that defines a minimum ventilation time (which may be a first time interval) in the form of a defined cycle time. If a specific fan speed is not reached, the counter or counter can be reset, so that the counting process of the counter or counter must restart.

[0039] As already mentioned, the fan may have a speed measuring device for measuring the tachometer signal and / or revolutions per unit time, or may be connected to such a speed measuring device. Implementations of the speed measuring device are known in the prior art; for example, speed measurement using a Hall sensor is possible. The inspection device may be part of or connected to the first control device. The power supply for the inspection device may be connected to the power supply of the first control device. Power supply to the inspection device may be performed using a power supply that is separate from and / or independent and / or spatially separated from other power supplies of the cooling laboratory equipment.

[0040] For example, a first predefined criterion may include a condition related to fan speed and / or a period of time during which the fan will operate at a specific fan speed. More specifically, the first predefined criterion may be, for example, a requirement to reach and / or not fall below a specific fan speed, which may also be referred to as a first predefined fan speed. The first predefined criterion may require reaching and / or not falling below a first predefined fan speed within a specific period of time, which may be a first time period. The condition that a certain fan speed (which may be the first predefined fan speed) must be reached within a certain time period (which may be the first time period) can be configured such that, at a certain fan speed and for a certain time, it is empirically ensured that the flammable refrigerant inside is completely or almost completely expelled from the interior. In particular, ventilation can be considered successful if the first predefined criterion has been met.

[0041] As already mentioned, the second control device can be, in particular, a software- and / or firmware-based control device. See the description above for the second control device. For example, the second control device can be configured to implement demand-based control of the fan. For example, the second control device can have a measurement sensor system (e.g., a temperature sensor for determining temperature values ​​in internal and / or external areas or a measurement probe for refrigerant concentration), by means of which ventilation requirements are determined (e.g., by means of rules and / or characteristics defined by integrated software / firmware side) and the corresponding fan speed can be determined.

[0042] For example, transmitting control of a fan can be a transmission of a check or control of the fan's power supply, for example, by means of a transmission device, which can be, for example, a suitable switch (e.g., an RS trigger) or can have a suitable switch (e.g., an RS trigger) that triggers a corresponding switching process. For example, the switch can be triggered when there is a capacitor output or the presence of a signal or voltage value, indicating successful ventilation. The transmission device can also have an electronic controller and / or a computing device (e.g., a processor) and / or a relay.

[0043] Specifically, the transfer can occur upon successful fulfillment of a first predefined criterion. If the first predefined criterion is not successfully met or ventilation is unsuccessful, the result may be that the transfer is not performed. In this case, for example, the operation of cooling laboratory equipment can be terminated or halted, for instance, based on predefined shutdown criteria, such as if the first predefined criterion is not met after a predefined period of time. If ventilation is unsuccessful, the cooling laboratory equipment may automatically shut down or not be turned on at all.

[0044] The second control device can typically be constructed to be more complex than the first control device, especially if it is software- and / or firmware-based. Because the first control device has a particularly simple structure, it can be exceptionally reliable or fail-safe, particularly more reliable or more fail-safe or less prone to error than the second control device. Therefore, the first control device is well-suited for initially ventilating the interior to remove any potentially flammable refrigerant from within in a particularly reliable manner. Furthermore, as mentioned above, reducing the risk of spark generation is advantageous.

[0045] In particular, additional checking equipment can be used to check whether the second predefined criterion has been met, such as a computing device (e.g., a processor) and commands, control adjustments and / or characteristics for checking the fan tachometer signal and / or a timer. Alternatively or additionally, it is not excluded that the checking device used to check the first predefined criterion may also be used to check whether the second predefined criterion has been met.

[0046] The other inspection device may be part of or connected to the second control device. The power supply for the other inspection device may be connected to the power supply for the second control device. The other inspection device may be powered by a power supply that is separate from and / or independent and / or spatially isolated from other power supplies of the cooling laboratory equipment.

[0047] For example, a second predefined criterion may include conditions related to fan speed and / or to a period of time during which the fan will operate at a specific fan speed. More specifically, a second predefined criterion may be, for example, a requirement to reach and / or not fall below a specific fan speed, which may also be referred to as a second predefined fan speed. A second predefined criterion may require reaching and / or not falling below a second predefined fan speed within a specific period of time.

[0048] Power to at least one other device to be powered can be activated, for example, by means of an activation device having a computing device (e.g., a processor) and corresponding commands. Activation can occur after a certain delay time, which, for safety reasons, must have elapsed after the transmission. For example, the delay time can be 5 seconds or 10 seconds. The delay time can also be shorter, for example, 5-1 seconds. Alternatively or additionally, the activation device can have a switch, such as a relay, for activating power to at least one other powered device, or can be connected to such a switch. In particular, activation can occur upon successful fulfillment of a second predefined criterion. The concept of other devices to be powered should be understood to exclude the fan itself from this concept.

[0049] At least one other device to be powered can be any other component of the cooled laboratory equipment being powered. In particular, it can be a component of the refrigeration circuit, such as a compressor, drive motor (e.g., if the cooled laboratory equipment is a centrifuge), display, or control device. Activating the power supply for at least one other device to be powered can also mean that the cooled laboratory equipment is (e.g., fully) turned on, so that operation of the cooled laboratory equipment (e.g., operation if it is a centrifuge) can begin.

[0050] This method can cause the activation of power to at least one component to be not performed, for example, for a predefined period of time, or before the cooling laboratory equipment is turned off and restarted, if the control or the second control method performed by the second control device is unsuccessful.

[0051] All the steps described above in this method can be performed automatically or executed. After the step of ventilating the interior, a check can be performed using a first predefined standard. After the check using the first predefined standard, control can be transferred. After the transfer step, a check can be performed using a second predefined standard. After the check using the second predefined standard, an activation step can be performed. This method ensures that the next step is performed only after each of the preceding steps has been completed.

[0052] The proposed method offers a simple and inexpensive way to improve the operational safety of laboratory equipment cooled by flammable refrigerants. Ventilation of the interior removes any potentially flammable refrigerant before the risk of spark formation associated with it arises. Furthermore, a trial run of the fans is conducted to detect fan malfunctions early. In addition to the fact of ventilation itself and the increased operational safety already provided, particularly fail-safety and independent hardware-based control (if the primary control unit is designed in this way), controlling ventilation and the ability to identify fan defects (e.g., mechanical blockages or contact problems) early and reliably are also advantageous, especially before a spark source within the cooled laboratory equipment is activated.

[0053] Equally advantageous is the ability to identify problems in the second control unit, which is capable of achieving customized fan speeds as required, particularly through pulse width modulation, provided it is designed accordingly. If necessary, the second control unit is advantageously activated only when a fault in the fan can be ruled out. Because the first control unit is substantially more reliable than the second, its initial use also effectively prevents potentially harmful fan malfunctions immediately after the cooling laboratory equipment is turned on.

[0054] Another advantage is that initial ventilation control, especially if it can be hardware-based, requires less expenditure in terms of development and approval. Other more complex and / or more expensive inspection or protection measures (such as pressure sensors) become redundant.

[0055] This invention is essentially applicable to all equipment containing refrigeration circuits with flammable refrigerants. It can also be applied to other equipment that has or generates hazardous gases or other vapors harmful to health.

[0056] In an advantageous embodiment of the method according to the invention, the power supply to the fan is established before the interior is ventilated, particularly immediately before the ventilation.

[0057] Preferably, power can be established using an on / off switch on the cooling laboratory equipment. The cooling laboratory equipment can be configured such that the on / off switch is the only switch that needs to be operated when the cooling laboratory equipment is started. Internal ventilation can then be started automatically. Less preferably, power can also be generated using a separate on / off switch.

[0058] "Immediately before ventilation" can mean that ventilation is carried out immediately after power is applied (e.g., by means of a switch to cool laboratory equipment), preferably within 5 seconds, or within 10 seconds, 20 seconds, or one minute.

[0059] The presented embodiments allow for a simple and user-friendly startup process. The startup process is particularly safe when power is supplied immediately before ventilation, as the fan is powered for a very short period before the interior space is ventilated, thus minimizing the risk of sparks from the fan itself.

[0060] In an advantageous embodiment of the method according to the invention, power to the fan is established during the startup process of the cooling laboratory equipment. Specifically, this may mean that power to the fan is automatically established when the cooling laboratory equipment is turned on, for example, via an on / off switch on the cooling laboratory equipment. After power to the fan is established, the startup process may include further steps. Further steps of the startup process can then be performed, particularly the control transfer of the fan and the activation of power to at least one other device to be powered for the cooling laboratory equipment.

[0061] The presented embodiments allow for a particularly simple and user-friendly startup process.

[0062] In an advantageous embodiment of the method according to the invention, the first control device is a hardware-based control device.

[0063] Referring to the above explanation regarding hardware-based control devices and the term "hardware-based," hardware-based control devices can have a particularly simple structure and can operate independently of other devices in the cooling laboratory equipment, thus being particularly reliable and fail-safe. Defects in the fan, such as blockages or contact problems, can be identified before other devices in the cooling laboratory equipment fail. If the fan fails, operation of the cooling laboratory equipment can continue to be suspended. This defect can advantageously be identified before the risk of refrigerant ignition due to other potential spark-generating devices in the cooling laboratory equipment, whose activation would be meaningless and potentially harmful in the event of fan failure.

[0064] In an advantageous embodiment of the method according to the invention, the second control device is a software-based or firmware-based control device.

[0065] Referring to the above description of software-based or firmware-based control devices and the terms "software-based" and "firmware-based," software-based or firmware-based control devices are advantageous because they particularly enable demand-based control of fans, especially demand-based control of fan speed. If ventilation requirements are low, for example because the internal temperature is already low, a low fan speed may be sufficient. A high fan speed should only be set when ventilation requirements are high, such as when the internal space temperature is high. This can be achieved, for example, using characteristic curves or characteristic plots. This implementation allows for low fan energy consumption, low wear and tear, long fan life, less maintenance, less contamination (e.g., due to internal dust), and less noise.

[0066] In an advantageous embodiment of the method according to the invention, the first criterion is or includes not less than or reaching a first predefined fan speed.

[0067] The expression "not less than" can specifically refer to a level not lower than a certain level within a specific time period. For example, the specific time period can particularly be a first time period. The determined time period can be a time period that, in combination with a first predefined fan speed, enables ventilation, allowing the flammable refrigerant to be completely or almost completely removed from the interior. A first predefined fan speed can be selected, which enables ventilation so that the flammable refrigerant is completely or almost completely removed from the interior within the specific time period.

[0068] For example, the length of a specific time period and the required fan speed can be determined on the basis of experimentation and / or with the help of simulation. The first predefined fan speed may alternatively be the (e.g., predefined) maximum speed at a specific voltage (e.g., 12V) or the nominal speed of the fan.

[0069] Reaching a first predefined fan speed can also serve as a primary criterion. For example, this might need to be achieved within a specific time period. For instance, it can be measured whether the first predefined fan speed was correctly reached and / or whether it was reached within a certain time period. This time period could be, for example, the typical acceleration time of the fan, such as within the range of 0.1 to 3 seconds. If the acceleration is too slow, i.e., if the first predefined fan speed is not reached within that time period, this may indicate a defect in the fan.

[0070] The first predefined fan speed can itself be a variable value. For example, the first predefined fan speed can depend on temperature, such as the internal space temperature or the external temperature, or on the period of time during which the cooling laboratory equipment is not running.

[0071] The presented embodiments allow for a reliable evaluation of the fan's functional capabilities in a simple and easy-to-implement manner with minimal cost in terms of control and testing techniques. In particular, the proper functioning of the fan itself can be tested in a simple way. For example, if proper control by the second control device fails, a fault in the fan itself (e.g., blockage, mechanical failure, contact problems, etc.) can already be ruled out.

[0072] In an advantageous embodiment of the method according to the invention, the second criterion is or includes a fan speed not less than a second predefined speed.

[0073] The expression "not less than" can specifically refer to not falling below a certain level within a further, specific time period. This further defined time period can be, for example, a period on the order of seconds (e.g., within the range of 2-20 seconds).

[0074] The second predefined fan speed can be a fan speed that ensures reliable ventilation during the (normal) operation of the cooling laboratory equipment. "Safety" here can refer to temperature, such as the internal temperature which must be maintained for safety reasons, or, for example, refrigerant escape, such as in the event of a leak. Here, "safety" can mean, for example, that the refrigerant discharged at the fan speed can be safely compensated for by removing it with the aid of ventilation. The second predefined fan speed can also be higher than the minimum fan speed (also referred to as the forced ventilation speed) that still ensures reliable ventilation during the (normal) operation of the cooling laboratory equipment.

[0075] The second predefined fan speed can itself be a variable value. For example, the second predefined fan speed can depend on temperature, such as the internal temperature or the external temperature.

[0076] The presented embodiments allow for reliable evaluation of the functionality of the second control unit (and fan) in a simple and easily implementable manner with minimal cost in terms of control and testing techniques. This prevents damage to other components of the cooling laboratory equipment. Typical ventilation conditions of the cooling laboratory equipment (such as those occurring during normal operation) can be simulated before normal operation actually begins.

[0077] In an advantageous embodiment of the method according to the invention, if the fan speed is lower than a second predefined fan speed, the fan speed is briefly increased by a first control device.

[0078] A brief increase in fan speed can also be referred to as an "acceleration." This brief increase can be performed specifically when the fan speed is slightly below a second predefined fan speed. In this case, it can be assumed, for example, that there is a mechanical problem with the fan, which can be resolved by a brief acceleration. For example, this could be due to dust accumulation on the fan. In terms of duration, the brief increase in speed can be, for example, in the range of 0.5 to 5 seconds, preferably in the range of 1 to 2 seconds. If the second predefined fan speed is not reached several times consecutively, the brief increase in speed can be performed multiple times consecutively.

[0079] A brief increase in speed may also correct the malfunction of the second control device causing a decrease in fan speed.

[0080] The presented embodiment can eliminate the root cause of excessively low fan speed in a simple manner and way. The cause can be mechanical in nature or originate from a secondary control device. In particular, this embodiment is user-friendly because it avoids the possibility of deactivating and / or restarting the main switch of the cooling laboratory equipment and / or even repairing the cooling laboratory equipment.

[0081] In an advantageous embodiment of the method according to the invention, if a third predefined criterion is violated, the power supply for at least one additional device to be powered is permanently or temporarily deactivated.

[0082] The third predefined standard can be, in particular, a fan speed not lower than the third predefined fan speed. The third predefined fan speed can also be the minimum fan speed (also known as the forced ventilation speed) that ensures reliable ventilation during the (normal) operation of the cooling laboratory equipment. The third predefined fan speed can be lower than the second predefined fan speed (if set).

[0083] Permanent shutdown can specifically involve disabling switches, such as relays, to power at least one other device that needs to be supplied with electricity. Switches or relays may affect the main power supply to the disabled cooling laboratory equipment. For example, it may remain disabled until the cooling laboratory equipment is subsequently turned on again, or for a predetermined period of time.

[0084] The presented embodiments increase operational safety because operation of the cooling laboratory equipment can be prevented in advance in the event of a failure in the second control unit and / or fan. In particular, identifying the fault before start-up can prevent damage to other equipment in the cooling laboratory or dangerous situations where refrigerant is not properly removed.

[0085] In an advantageous embodiment of the method according to the invention, the power supply for at least one additional device to be powered is activated only after the second time period has elapsed, which begins when or after the fan control has been transmitted to the second control device.

[0086] For example, the second time period can be understood as the minimum time period during which checks based on a second predefined standard must be performed regardless of circumstances. This further enhances the information value and quality of checks performed using the second predefined standard, thereby further improving the operational safety of the cooling laboratory equipment.

[0087] In an advantageous embodiment of the method according to the invention, before ventilating the interior of the cooling laboratory equipment, it is checked whether the power supply for at least one additional device to be powered is disabled and / or whether the fan speed detection is functioning properly.

[0088] The above measures prevent at least one other device to be powered from being powered, for example due to a malfunction, during internal ventilation or in the process of the method according to the invention, and thus represent a potential source of sparks. For example, if the other device to be powered can be powered by a relay, it can be checked whether the relay is properly activated.

[0089] For example, the correct function of fan speed detection can be configured to check whether a fan that is still stationary before internal ventilation is correctly outputting a signal that its speed is zero.

[0090] If the power supply is disabled and / or the fan speed detection fails to function correctly, further steps of the method according to the invention, particularly ventilation, can be prevented. This further enhances operational safety. In particular, proper fan speed detection further increases the likelihood that further method steps can be performed correctly and as specified, especially if the first predefined criterion and / or the second predefined criterion (and possibly a third predefined criterion) both depend on the fan speed.

[0091] Furthermore, an object for a laboratory device cooled by a flammable refrigerant is proposed, the device having:

[0092] - A fan configured to provide internal ventilation to the cooled objects of the cooling laboratory equipment;

[0093] - A first control device configured to control a fan such that internal ventilation occurs during a first time period;

[0094] - An inspection device configured to check whether ventilation is successful within a first time period using a first predefined standard;

[0095] - A second control device configured to control the fan;

[0096] - A transmission device configured to transmit fan control to a second control device if ventilation is successful in the first time period.

[0097] - Activation device, which is configured to activate the power supply of at least one additional device to be supplied with power for cooling the object of the laboratory equipment if the fan is successfully controlled by the second control device.

[0098] The inspection device is further configured to check whether the fan is successfully controlled by the second control device ST2 using a second predefined standard, or whether the object being cooled by the cooling laboratory equipment has an additional inspection device, which is configured to check whether the fan is successfully controlled by the second control device using a second predefined standard.

[0099] Cooling laboratory equipment can be specifically configured to implement the method according to the invention, particularly automatically, in at least one of the presented embodiments. Reference is made herein to the cooling laboratory equipment and embodiments thereof, entirely with regard to the method according to the invention and embodiments thereof. Reference is made herein specifically (but not exclusively) to the cooling laboratory equipment, flammable refrigerant, fan, interior, first control device, first time period, inspection device, first predefined standard, second predefined standard, ventilation, second control device, transmission device for controlling the fan and transmitting control, activation device, additional device to be powered, and additional inspection device.

[0100] Specifically, the first control device, the inspection device, the second control device, the transfer device, the activation device, and / or other transfer devices may be units integrated into the cooling laboratory equipment. The aforementioned devices may each, at least partially or wholly include at least one electronic component and / or a programmable computing device and / or use or share a programmable computing device. The first control device preferably does not have a programmable computing device and / or is not connected to or is only indirectly connected to the programmable computing unit.

[0101] In one embodiment, the cooling laboratory equipment may be, in particular, a laboratory refrigerator or a centrifuge. Attached Figure Description

[0102] Embodiments of the invention will now be described with reference to the accompanying drawings. In the various figures of the drawings:

[0103] Figure 1 An embodiment of a cooling object in a laboratory apparatus according to the present invention is illustrated schematically;

[0104] Figure 2 Another embodiment of a cooling object in a laboratory apparatus according to the invention is illustrated schematically;

[0105] Figure 3 An embodiment of the method according to the present invention is illustrated schematically.

[0106] In various exemplary embodiments, the same reference numerals are used for apparatuses, steps, instances, and elements having the same function. However, this does not necessarily mean that the exemplary embodiments are the same exemplary embodiments or part of the same exemplary embodiments. Detailed Implementation

[0107] Figure 1 A cooling object of laboratory equipment 1 according to the invention is shown, embodied as a laboratory centrifuge. However, the invention is not limited to laboratory centrifuges. For example, the cooling object of laboratory equipment 1 could also be a laboratory refrigerator. The cooling laboratory equipment 1 has a fan 2. A speed sensor 22 and a fan motor 21 are disposed on the fan 2, more precisely on the fan shaft. The speed sensor 22 and the fan motor 21 can be understood as components of the fan 2. The fan 2 is located at a first opening OE1 of the housing 11 of the cooling laboratory equipment 1. The housing 11 may have an openable cover (not shown) to establish access to the centrifuge rotor 4. The centrifuge rotor 4 can be rotated by a drive motor 5 integrated in the housing. The centrifuge rotor 4 is also rotatably mounted by a rotor bearing 52 integrated in the housing, which can be embodied, for example, as a roller bearing. A second opening OE2 is provided on the side of the housing 11 opposite to the first opening OE1 to allow ventilation through the interior 3. Additional openings (not shown) may be provided.

[0108] The cooling laboratory equipment 1 has an interior 3. The interior 3 extends substantially below the centrifuge rotor 4, i.e., away from the top of the centrifuge rotor, and has an inclined insertion area for sample tubes, extending to the lower side of the cooling laboratory equipment 1. Inside the interior 3, a small amount of refrigerant KM is present in the cooling laboratory equipment 1 in the illustrated state, for example, due to a small leak in the refrigeration circuit KM and prolonged disuse of the cooling laboratory equipment. The refrigerant KM is a flammable refrigerant, such as propane.

[0109] The cooling laboratory equipment 1 has a refrigeration circuit KAE. The refrigeration circuit KAE has multiple evaporators 6 (i.e., refrigeration units). These are specifically used to cool the centrifuge rotor 4, the surrounding environment of the centrifuge rotor 4, the drive motor 5, and the rotor bearing 52. The refrigeration circuit KAE also has a compressor 7 (e.g., a compressor unit), a condenser 8 (which may be a liquefier) ​​located outside the housing 11, and a throttle valve 9. The compressor 7 is connected to a power supply line 73 for supplying power to the compressor 7. The drive motor 5 is connected to a power supply line 53 for supplying power to the drive motor 5. According to the general description, the compressor 7 and the drive motor 5 can be understood as additional devices to be powered for cooling the laboratory equipment 1.

[0110] The cooling laboratory equipment 1 is powered by an external power supply EX (which may have a mains plug and possibly a mains section) and a mains cable EXN. The mains cable EXN interfaces with the on / off switch 10 of the cooling laboratory equipment. The on / off switch 10 has a push-button for turning the circuit on / off (shown herein). The on / off switch 10 allows current to flow when connected via power lines 103, ST13, UEP3, and ST23. The power lines that can be used to establish the circuit are explained in more detail below.

[0111] Power line ST13 extends from on / off switch 10 to first control device ST1. Power line ST23 extends from on / off switch 10 to second control device ST2. Power line 103 extends from on / off switch 10 to activation device AKE. Power line UEP3 extends from on / off switch 10 to inspection device UEP.

[0112] The first control device ST1 is configured to allow ventilation of the interior 3 of the fan 2 for a first time period, which may last for, for example, 8-10 seconds. In this case, voltage may be present on the fan 2, causing the fan 2 to operate at its maximum speed, for example, at least 2500 revolutions per minute.

[0113] The first control unit ST1 is hardware-based. It has a switch that provides power to the fan 2 (more precisely, the fan motor 21), with power source ST13, which ultimately supplies power to both the fan 2 and the first control unit ST1 itself. This switch can essentially be turned on or off, automatically switched on or off during the initial operation of the cooling laboratory equipment 1, or automatically switched on within a first time period. For an explanation of the term "hardware-based," please also refer to the general section of the specification.

[0114] In principle, the scope of this invention does not preclude the first control device ST1 from alternatively or additionally having a controller via a chip or processor and control commands capable of controlling the fan 2 (fan motor 21) or the power supply of the fan 2. It is not precluded that the first control device ST1 is configured to set the speed of the fan 2 (fan motor 21), for example, by means of pulse width modulation. However, in principle, it is preferred that the first control device ST1 has a simple structure and implements its function, for example, by means of the aforementioned switch (which may be an on / off switch).

[0115] Interface ST1-UEG is used to control the fan and / or supply power to fan 2 (fan motor 21). Interface ST1-UEG can be configured to transfer or conduct electrical energy (and / or alternatively or additionally, control commands) from the first control device ST1 to the transmission device UEG. Interface ST1-UEG can therefore have power lines that can create a power circuit, and may also have data lines. The transmission device UEG is configured to transfer control of fan 2 (fan motor 21) from the first control device ST1 to the second control device ST2, or vice versa. For this purpose, the transmission device UEG can have a switch that can, in particular, perform a change in the power supply of fan motor 21 between the first control device ST1 and the second control device ST2. Interface UEG-2 leads from the transmission device to fan 2 (fan motor 21), which has power lines (which can establish a circuit) so that fan motor 21 can be powered. It cannot be ruled out that interface UEG-2 also has a data cable, for example, if fan 2 is designed accordingly (e.g., if it has its own separate control device).

[0116] In addition, a check device UEP is provided. It is configured to check whether the internal ventilation is successful within a first predefined time period using a first predefined criterion. The first predefined criterion may be reaching and maintaining a first predefined fan speed (e.g., 2500 revolutions per minute) for a minimum time period (corresponding to the first time period, which may be, for example, 8 seconds) for safe ventilation. Other embodiments of the first predefined criterion are not excluded.

[0117] In the embodiment of the cooling laboratory equipment 1 presented according to the invention, the inspection device UEP is configured to have a computing device (e.g., a processor) and corresponding commands. It cannot be ruled out that the inspection device UEP may be constructed in different ways, particularly in a simpler configuration, such as being configured as a capacitor that charges once a certain fan speed is reached and reaches a certain voltage value (threshold switching) after (at the earliest) a first time period, which would trigger a switching at the transmission device UEG.

[0118] Alternatively or additionally, it is also possible that the inspection device UEP has a timing device that starts the time measurement process once a first predefined fan speed is reached, and triggers a switch at the transmission device UEG once the first time period expires.

[0119] The inspection device UEP is connected to the speed sensor 22 via interface 22-UEP and can therefore receive the fan speed signal to check whether a first predefined criterion is met. Interface 22-UEP is configured to transmit the fan speed signal from the speed sensor 22 (e.g., it can be configured as a Hall sensor), thereby receiving the signal and interpreting it to check whether internal ventilation is successful in a first time period. Reception and interpretation are performed by the inspection device UEP. All mentioned interfaces, including interface 22-UEP, may, for example, have power and / or data cables.

[0120] In addition, the inspection device UEP is connected to the first control device ST1 via an optional interface UEP-ST1. Through the optional interface UEP-ST1, the inspection device UEP can, for example, check whether the switch of the first control device ST1 was correctly switched during a first time period, within the framework of checking whether ventilation was successful.

[0121] Furthermore, the inspection device UEP is connected to the transmission device UEG via interface UEP-UEG. If a first predefined criterion is met, namely successful ventilation of interior 3, a signal is sent from the first control device ST1 (and interface ST1-UEG) to the transmission device UEG via interface UEP-UEG, allowing switching from the first control device ST1 (and interface ST1-UEG) to the second control device ST2 (and interface ST2-UEG). Therefore, for example, switching of the transmission device UEG can be implemented. For this purpose, the transmission device UEG can be configured to switch based on this signal.

[0122] The second control device ST2 is configured to control fan 2, for example, by means of pulse width modulation (PWM). The second control device ST2 is firmware-based. This can specifically mean that it has memory, such as ROM memory, containing control commands, such as functional relationships or (predetermined) characteristics that enable fan 2 (fan motor 21) to be controlled as needed, for example, based on temperature values ​​measurable by a temperature sensor (not shown) in internal 3 and / or a temperature sensor external to internal 3. It is not excluded that the second control device ST2 may alternatively or additionally be software-based, for example, having read-write memory containing adaptable control commands. The second control device ST2 also includes a computing device, such as a processor, to execute and interpret the control commands.

[0123] The second control device ST2 can be configured to control fan 2 during normal operation of the cooling laboratory equipment.

[0124] The ST2-UEG interface is used to control and / or supply power to fan 2 (fan motor 21). The ST2-UEG interface can be configured to transfer or conduct electrical power and / or control commands from the second control device ST2 to the transmission device UEG. The ST2-UEG interface may have power lines that can create a power circuit and may also have data lines. The transmission device UEG is configured to transmit control of fan 2 (fan motor 21) to the second control device ST2. When transmission has occurred, power is supplied to fan 2 (fan motor 21) through the ST2-UEG interface and an additional UEG-2 interface.

[0125] In the embodiment of the cooling laboratory equipment 1, the inspection device UEP is configured to check whether the fan 2 is successfully controlled by the second control device ST2 using a second predefined criterion. The second predefined criterion that must be met is that, during a second time period, the fan speed must not be lower than the predefined minimum speed for safe basic ventilation (the second predefined fan speed). For example, the second time period can be 5 seconds long. For example, the second predefined fan speed can be 1100 revolutions per minute.

[0126] The inspection device UEP is connected to the speed sensor 22 via interface 22-UEP and can therefore receive the fan speed signal to check whether the second predefined criterion is met. The inspection device UEP may also have a time measurement device.

[0127] Interface 22-UEP is configured to transmit a fan speed signal from speed sensor 22, thereby receiving the signal and interpreting it for checking whether the control was successful in a second time period. Reception and interpretation are performed by the checking device UEP.

[0128] Furthermore, the inspection device UEP is connected to the second control device ST2 via the optional interface UEP-ST2. Through the optional interface UEP-ST2, the inspection device UEP, in addition to checking the success of control during a second time period, can also check, for example, whether the second control device ST2 correctly controls the fan 2 during that second time period.

[0129] If control is successful in the second time period, i.e., the second predefined criterion is met, then a signal is transmitted via interface UEP-AKE to the activation device AKE to activate the power supply for compressor 7 (via power line 73) and drive motor 5 (via power line 53). The activation device 103 specifically includes a switch, such as a relay, which can establish power when a corresponding signal is present.

[0130] Cooling laboratory equipment 1 is shown in a state where coolant KM is located inside interior 3. The control of the first control device ST1 (ventilation of interior 3 during a first time period) has completely removed the refrigerant KM from interior 3, so that when other electrically powered devices (compressor 7 and drive motor 5) that could potentially generate sparks are activated in cooling laboratory equipment 1, there is no longer any refrigerant and no longer a risk. At the activation point, the control of fan 2 via the second control device ST2 is also checked to ensure it is operating normally. The second control device ST2 also controls the fan during normal operation of cooling laboratory equipment 1, where the fan can be connected.

[0131] Optionally, the checking device UEP can also be configured to initiate a brief speed increase via the first control device ST1 if the fan speed is lower than the second predefined fan speed (the minimum speed for safe basic ventilation during operation) during a second predefined time period. The checking device UEP can be configured (in particular, it can have appropriate control commands) to instruct the transmission device UEG to perform a switching process to the first control device ST1 in this case. For example, the short-term speed increase can be achieved by switching back to the previous short period (e.g., 1 second). The checking device UEP can be configured to restart the second time period after the brief speed increase to check whether the control of the second control device ST2 was successful.

[0132] The inspection device UEP may optionally be additionally configured to enable the switch (e.g., a relay) of the activation device AKE for the power supply to the compressor 7 (via power line 73) and the drive motor 5 (via power line 53) to be deactivated or locked for a specific period of time or permanently (e.g., until the cooling laboratory equipment 1 is restarted) if the speed drops below a third predefined (critical) fan speed, which no longer guarantees safe operation in the event of a leak. For example, the third predefined fan speed may be 500 revolutions per minute.

[0133] The inspection device UEP can also optionally be configured to check the correct state of the signal from the speed sensor 22 and / or the activation device AKE before a first time period, i.e., before the start of ventilation in the interior 3. For this purpose, the inspection device UEP may have corresponding control commands. The signal from the speed sensor (also referred to as the speed signal) should initially correspond to zero fan speed. The switch of the activation device AKE should be deactivated. If at least one of these criteria is not met, the inspection device UEP may be configured to enable the switch (e.g., a relay) of the activation device AKE (to supply power to the compressor 7 (via power line 73) and the drive motor 5 (via power line 53) to be deactivated or locked for a specific time period or permanently (e.g., until the cooling laboratory equipment 1 is restarted).

[0134] Figure 2 Another embodiment of the cooling laboratory equipment 101 according to the present invention is shown. However, the cooling laboratory equipment 101 shown now has a first inspection device UEP1 and a second inspection device UEP2 compared to the cooling laboratory equipment 101. The (general) inspection device UEP is not present.

[0135] The notes for the first presented embodiment of the cooling laboratory equipment 1 apply accordingly, except for the following description: the first inspection device UPE1 and the second inspection device UEP2, as well as interfaces 22-UEP1, 22-UEP2, UEP2-ST2, UEP2-AKE and UEP2-UEG, and the power cord UEP23. The power cord UEP23 extends from the on / off switch 10 to the second inspection device UEP2.

[0136] The first inspection device UEP1 is configured to check whether internal ventilation is successful within a first time period using a first predefined criterion. The first predefined criterion is to achieve and maintain a first predefined fan speed (e.g., 2500 revolutions per minute) for a minimum time period (corresponding to the first time period, which may be, for example, 8 seconds) for safe ventilation. In this way, any potentially hazardous mixtures may be neutralized within the cooling laboratory equipment. Other embodiments of the first predefined criterion are not excluded.

[0137] The first checking device UEP1 has a threshold switch (e.g., a capacitor that charges once a first predefined fan speed is reached). Alternatively or additionally, it may have a timing device that starts the time measurement process once the first predefined fan speed is reached.

[0138] The first inspection device UEP1 is connected to the speed sensor 22 via interface 22-UEP1 and can therefore receive the fan speed signal to check whether the first predefined criterion is met.

[0139] The interface UEP1-UEG transmits information about reaching a specific voltage value for the capacitor or the minimum time interval of the measurement process to the transmission device UEG. This information may indicate that the ventilation of the cooling laboratory equipment has been successful.

[0140] This triggers a switch at the transmission device UEG, allowing switching from the first control device ST1 (and interface ST1-UEG) to the second control device ST2 (and interface ST2-UEG), thus enabling the switching of the transmission device UEG. The transmission device UEG is therefore configured to switch based on information.

[0141] Interface 22-UEP1 is configured to transmit a fan speed signal from speed sensor 22 (e.g., which may be configured as a Hall sensor), such that a threshold switch (e.g., a charged capacitor) or an alternative timer / counter to the first checking device UEP1 can be used to check whether a first predefined criterion is met.

[0142] In the embodiment of the cooling laboratory equipment 101, the second inspection device UEP2 is configured to check whether the fan 2 is successfully controlled by the second control device ST2 using a second predefined criterion. The second predefined criterion that must be met is that, during a second time period, the fan speed must not be lower than a second predefined fan speed (this could be a predefined minimum speed for basic ventilation). For example, the second time period could be 5 seconds long. For example, the second predefined fan speed could be 1100 revolutions per minute.

[0143] The second inspection device UEP2 is connected to the speed sensor 22 via interface 22-UEP2 and can therefore receive the fan speed signal to check whether the second predefined standard is met.

[0144] Interface 22-UEP2 is configured to transmit a fan speed signal from speed sensor 22, thereby receiving the signal and interpreting it for checking whether the control was successful in a second time period. Reception and interpretation are performed by the second checking device UEP2.

[0145] Furthermore, the second inspection device UEP2 is connected to the second control device ST2 via an optional interface UEP-ST2. Through the optional interface UEP-ST2, the second inspection device UEP can, for example, check whether the second control device ST2 is correctly controlling the fan 2, within the framework of checking whether control is successful in a second time period. It cannot be ruled out that the second inspection device UEP and the second control device ST2 are configured as a common unit.

[0146] If control is successful in the second time period, i.e., the second predefined criterion is met, then a signal is transmitted via interface UEP2-AKE to the activation device AKE to activate the power supply for compressor 7 (via power line 73) and drive motor 5 (via power line 53). The activation device 103 specifically includes a switch, such as a relay, which can establish power when a corresponding signal is present.

[0147] The second checking device UEP2 can exchange information with the transmitting device UEG via the interface UEP2-UEG. Therefore, for example, the second checking device UEP2 can also be optionally configured to initiate a brief speed increase via the first control device ST1 if the fan speed is lower than a second predefined fan speed (the specified minimum speed for safe basic ventilation during operation). The second checking device UEP2 can be configured (in particular, it can have appropriate control commands) to instruct the transmitting device UEG to perform a switching procedure to the first control device ST1 in this case. The short-term speed increase can be brief (e.g., within a 1-second time period) until switching back (a brief acceleration of fan 2 to avoid falling below the critical speed). The second checking device UEP2 can be configured to restart a second time period after the brief speed increase to re-check the success of the control by the second control device ST2.

[0148] The second inspection device UEP2 may optionally be additionally configured to enable the switch (e.g., a relay) of the activation device AKE for the power supply to the compressor 7 (via power line 73) and the drive motor 5 (via power line 53) to be deactivated or locked for a specific period of time or permanently (e.g., until the cooling laboratory equipment 101 is restarted) if the speed is lower than a third predefined fan speed, which no longer guarantees safe operation in the event of a leak. For example, the third predefined fan speed may be 500 revolutions per minute.

[0149] The second inspection device UEP2 can also optionally be configured to check the correct status of the signal from the speed sensor 22 and / or the activation device AKE before the first time period, i.e., before the start of ventilation in the interior 3. For this purpose, the second inspection device UEP2 can have corresponding control commands. The signal from the speed sensor (also referred to as the speed signal) should initially correspond to zero fan speed, and the switch of the activation device AKE should be deactivated.

[0150] If at least one of these criteria is not met, the second inspection device UEP2 may be configured to enable the switch (e.g., a relay) of the activation device AKE for the power supply to the compressor 7 (via power line 73) and the drive motor 5 (via power line 53) to be deactivated or locked for a specific period of time or permanently (e.g., until the cooling laboratory equipment 101 is turned on again).

[0151] Figure 3An embodiment of the method according to the invention is shown for use in operating an object (e.g., a laboratory centrifuge or laboratory freezer) cooled by a flammable refrigerant. For example, the cooled laboratory equipment may be cooled laboratory equipment 1 or cooled laboratory equipment 101. Where applicable, full reference is made to the above explanation of embodiments of cooled laboratory equipment according to the invention, with reference to the relevant description. Cooled laboratory equipment 1 and cooled laboratory equipment 101 may be configured to perform the method according to the invention, particularly automatically.

[0152] In the optional upstream control step SCK, it is checked that the power supply to other devices to be powered has been properly disabled. Other devices to be powered may be, for example, the drive motor 5 and / or compressor 7, or the display or electric opening mechanism of the lid cooling the laboratory equipment.

[0153] In addition, the fan speed detection can be checked in the control step SCK to see if it is working properly, for example by checking if the fan speed signal is equal to 0 at the beginning.

[0154] In preparatory step SC0, check whether the fan has reached or exceeded the predetermined minimum speed for reliable ventilation. If not, the cooling laboratory equipment can be stopped and automatically shut down.

[0155] After performing the preparatory steps, in the first step SC1, the interior of the cooling laboratory equipment (e.g., interior 3) is ventilated for a first time period. In this case, the fan is controlled by a first control device (e.g., first control device ST1), which may in particular be hardware-based. The first time period is selected such that at a first predefined fan speed, there is no refrigerant, either completely or almost completely, present inside the cooling laboratory equipment.

[0156] After ventilation has been performed, a second step, SC2, checks whether a first predefined criterion is met (e.g., reaching a fan speed of at least 2500 revolutions per minute within 8 seconds, which may be referred to as the first predefined speed), for example, using a simple inspection device, such as the first inspection device UEP1. As mentioned above, alternatively or additionally, successful ventilation can be achieved using a more complex inspection device, such as inspection device UEP.

[0157] Any refrigerant that may have been present inside has now been completely or almost completely removed, so that other devices in the laboratory equipment that need to be powered will not pose a spark hazard before being powered on.

[0158] In the third step SC3, if the fan control is successful (indicated by a checkmark), the fan control is transferred to a second control device, such as via a transfer device UEG. The second control device may be, in particular, a software or firmware-based control device and has stored control commands and / or features.

[0159] If fan control fails (indicated by "x"), the method can be terminated. Specifically, the cooling laboratory equipment can be automatically shut down, as indicated by the symbol "O".

[0160] In the fourth step SC4, the success of fan control is checked using a second predefined criterion (e.g., the fan speed must not be lower than a predefined minimum speed for permanent, safe ventilation, which may be referred to as the second predefined fan speed).

[0161] If this is not the case, but the third predefined criterion is not violated (e.g., the fan speed drops below a predefined critical speed, which can be referred to as the third predefined fan speed, where this speed no longer ensures safe operation in the presence of a leak), in optional additional step SC4B, control can be briefly transferred to the first control unit, resulting in a brief increase (acceleration) in the fan speed direction towards maximum speed. Afterward, step SC4 can be performed again. Optional additional step SC4b can be performed a limited number of times. If the second predefined criterion is still not met, an abort can be performed, for example, by shutting down the cooling laboratory equipment (not shown).

[0162] The success of fan control can be checked using a testing device (such as testing device UPE or second testing device UEP2).

[0163] If ventilation is successful (indicated by a checkmark), and if necessary, with a time delay (indicated by a clock symbol), then in step SC5, other devices to be powered are activated, for example by means of an activation device, so that normal operation of the cooling laboratory equipment can begin.

[0164] List of reference numerals

[0165] 1: Cooling laboratory equipment

[0166] 10: On / Off Switch

[0167] 101: Cooling Laboratory Equipment

[0168] 103: Power cord

[0169] 11: Shell

[0170] 2: Fan

[0171] 21: Fan motor

[0172] 22: Speed ​​sensor

[0173] 22-UEP: Interface between the speed sensor and the detection device

[0174] 22-UEP1: Interface between the speed sensor and the first detection device

[0175] 22-UEP2: Interface between the speed sensor and the second detection device

[0176] 3: Internal

[0177] 4: Centrifuge rotor

[0178] 5: Drive motor

[0179] 51: Rotor shaft

[0180] 52: Rotor bearing

[0181] 53: Drive motor power cable

[0182] 6: Evaporator (Refrigeration Unit)

[0183] 7: Compressor (e.g., compressor)

[0184] 73: Compressor power cord

[0185] 8: Condenser (Liquefied Tank)

[0186] 9: Throttling valve

[0187] AKE: Activation device

[0188] EX: External power supply

[0189] EXN: Power cable

[0190] KAE: Refrigeration circuit

[0191] KM: Refrigerant

[0192] OE1: First Opening

[0193] OE2: Second opening

[0194] ST1: First Control Device

[0195] SC1: First Step

[0196] ST13: Power cord for the first control device

[0197] ST1-UEG: Interface between the first control device and the transmission device

[0198] ST2: Second Control Device

[0199] SC2: Second Step

[0200] ST23: Power cord for the second control device

[0201] ST2-UEG: Interface between the second control device and the transmission device

[0202] SC3: Third Step

[0203] SC4: Fourth Step

[0204] SC4B: Additional Steps

[0205] SC5: Step Five

[0206] SCK: Control Procedure

[0207] UEG: Transmission device

[0208] UEG-2: Interface between the transmission device and the fan

[0209] UEP: Inspection Device

[0210] UEP1: First Inspection Device

[0211] UEP2: Second Inspection Device

[0212] UEP23: Power cord for the second inspection device

[0213] UEP2-AKE: Interface between the second inspection device and the activation device

[0214] UEP2-ST2: Interface between the second inspection device and the second control device

[0215] UEP2-UEG: Interface between the second inspection device and the transfer device

[0216] UEP3: Check the power cord of the device

[0217] UEP-AKE: Interface between the inspection device and the activation device

[0218] UEP-ST1: Inspection device and first control device interface

[0219] UEP-ST2: Inspection device and second control device interface

[0220] UEP-UEG: Interface between inspection device and transmission device

Claims

1. A laboratory apparatus for operating a system cooled by a flammable refrigerant (1; A method for an object (101), the method comprising: - Ventilation is provided inside (3) of the laboratory equipment (1; 101) by means of a fan (2), wherein the control of the fan (2) is performed by a first control device (ST1) during a first time period, wherein the first control device is a hardware-based control device; - Check whether the ventilation is successful using a first predefined criterion, wherein the first predefined criterion is a speed not lower than that of a first predefined fan; - If ventilation is successful during the first time period, the control of the fan (2) is transmitted to the second control device (ST2). - Check whether the second control device (ST2) has successfully controlled the fan (2) using a second predefined standard, wherein the second predefined standard is a speed not lower than that of the second predefined fan; - If the fan (2) is successfully controlled by the second control device (ST2), the power supply for at least one other electrical device for the laboratory equipment (1; 101) is activated.

2. The method according to claim 1, characterized in that, Power is supplied to the fan (2) before ventilating the interior (3).

3. The method according to claim 2, characterized in that, The power supply to the fan (2) is established by the start-up process of the laboratory equipment (1; 101).

4. The method according to claim 1, characterized in that, The second control device (ST2) is a software-based or firmware-based control device.

5. The method according to claim 1, characterized in that, If the speed is lower than the second predefined fan speed, the speed of the fan (2) is briefly increased by the first control device (ST1).

6. The method according to claim 1, characterized in that, If a third predefined standard is violated, the power supply for the at least one other electrical device shall be permanently or temporarily deactivated, wherein the third predefined standard is a speed not lower than that of a third predefined fan.

7. The method according to claim 1, characterized in that, Power for the at least one other electrical device is activated only after the second time period has elapsed, which begins when or after the fan control has been transmitted to the second control device (ST2).

8. The method according to claim 1, characterized in that, Before ventilating the interior (3) of the laboratory equipment (1; 101), check whether the power supply for the at least one other electrical device is disabled and / or whether the fan speed detection is working properly.

9. A laboratory device cooled by a flammable refrigerant (KM) (1; 101) an object, said object comprising: - Fan (2), the fan being configured to ventilate the interior (3) of the laboratory equipment (1; 101); - First control device (ST1), the first control device is a hardware-based control device, the first control device is configured to control the fan (2) so that ventilation of the interior (3) occurs in a first time period; - Inspection device (UEP; UEP1), the inspection device is configured to check whether ventilation is successful during a first time period using a first predefined standard, the first predefined standard being a speed not lower than that of a first predefined fan; - Second control device (ST2), the second control device is configured to control the fan (2); - A transmission device (UEG) configured to transmit control of the fan (2) to a second control device (ST2) if ventilation is successful during the first time period. - Activation device (AKE), which is configured to activate the power supply for at least one other electrical device of the laboratory equipment (1; 101) if the fan (2) is successfully controlled by the second control device (ST2); The inspection device (UEP) is further configured to check whether the fan (2) is successfully controlled by the second control device (ST2) using a second predefined standard, or whether the laboratory equipment (1; 101) has an additional inspection device (UEP2) configured to check whether the fan (2) is successfully controlled by the second control device (ST2) using a second predefined standard, the second predefined standard being a speed not lower than that of the second predefined fan.

10. The object according to claim 9, characterized in that, The laboratory equipment (1; 101) is a laboratory refrigerator or centrifuge.

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