air conditioning device
The air conditioning device addresses energy management issues by adjusting compressor speed based on load conditions, ensuring efficient cooling capacity within power supply limits, even in fluctuating environments.
Patent Information
- Application Number
- DE112024002848
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-07-05
- Filing Date
- 2024-06-21
- Publication Date
- 2026-04-16
AI Technical Summary
Existing air conditioning devices using a cigarette lighter charger as a power supply face challenges in efficiently managing energy consumption due to fluctuating load conditions, leading to excess capacity in high-load situations and inefficiency in low-load conditions, particularly when condensate is reused to cool the condenser.
An air conditioning device with a control system that adjusts the compressor speed based on load conditions, using a unit to determine an upper operating limit and speed command value, ensuring efficient energy use within the power supply's current limitations.
The device effectively manages energy consumption by controlling compressor speed according to load, ensuring efficient cooling capacity without exceeding power supply limits, even in varying environmental conditions.
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Abstract
Description
TECHNICAL AREA
[0001] The present invention relates to an air conditioning device. STATE OF THE ART
[0002] A relatively compact air conditioning device (a so-called point cooler or portable cooler) is known from the prior art, in which a refrigerant circuit with a compressor, a condenser, an expansion device, an evaporator, and a fan are housed in a single casing, with the condenser located below the evaporator. An embodiment of such an air conditioning device is also known in which condensate (drain water) generated at the evaporator flows to the condenser and cools it, thereby improving the coefficient of performance (COP) (see, for example, patent document 1). Power supplies for such an air conditioning device (point cooler, portable cooler) include, among others, an AC power supply, a battery, and a vehicle cigarette lighter charger. LIST OF REFERENCE DOCUMENTS PATENT DOCUMENTS
[0003] Patent document 1: JP 2022-148686 A BRIEF SUMMARY OF THE INVENTIONAL TASKS OF THE INVENTION
[0004] However, in the case of an air conditioning device whose power supply is a cigarette lighter charger, it is difficult to effectively use the power for air conditioning (cooling).
[0005] Specifically, the energy consumption of the air conditioning unit fluctuates significantly depending on the external environment. In a high-temperature, high-humidity environment, i.e., when the air conditioning unit is operating at a high load, the energy consumption is high. Conversely, in a low-temperature, low-humidity environment (when the air conditioning unit is operating at a low load), the energy consumption is low. In the case of a cigarette lighter charger, the supply voltage is either 12 V or 24 V. Therefore, if an upper limit for the cooling capacity is set during low-load operation, the current limit of the cigarette lighter charger will be exceeded if a high-load condition occurs.Therefore, the upper limit for cooling capacity must be set to the operating range of the high load condition, but in this case, excess air conditioning capacity results in the low load condition.
[0006] In particular, if, as in the technology described in patent document 1, the energy consumption coefficient (COP) is to be improved and the air conditioning device is designed such that the condensate is reused to cool the condenser, the efficiency of the cooling cycle increases once some time has passed after the start of operation and the condenser is cooled by the generated condensate, while the required energy drops sharply. In this case as well, for safety reasons, the upper limit of the cooling capacity in the prior art is set to match the state before the generation of condensate, i.e., the low-efficiency state of the cooling cycle. Therefore, if the high-efficiency state of the cooling cycle is reached some time after the start of operation due to the generation of condensate, the problem arises that the cooling capacity cannot be increased, even though there is potential for increased energy consumption.
[0007] The present invention was made in view of this circumstance, and its objective is to provide an air conditioning device in which, in a comparatively compact air conditioning device in which the condenser is arranged below the evaporator, the energy used is controlled within a current limitation of the power supply and air conditioning power (cooling power) can be used effectively. SOLUTION OF THE TASKS
[0008] The present invention relates to an air conditioning device comprising a housing in which a refrigerant circuit with a compressor, a condenser, a pressure reducing device and an evaporator and a control device are accommodated, and is characterized in that the control device has a unit for determining the upper operating limit, a unit for determining the speed command value and a compressor speed control unit, wherein the unit for determining the upper operating limit performs a control to determine an upper operating limit according to a load on the compressor, which is an upper speed limit for driving the compressor, wherein the unit for determining the speed command value performs a control in which, in the case of a relatively low load,a speed command value is determined according to a target discharge temperature and a current speed of the compressor (hereinafter referred to as "current speed") and, in the case that the load is relatively high, the current speed or the upper operating limit is determined as the speed command value, whereby the compressor speed control unit controls the drive of the compressor based on the speed command value. EFFECTS OF THE INVENTION
[0009] According to the present invention, the excellent effect can be achieved that an air conditioning device can be provided in which, in a comparatively compact air conditioning device in which a condenser is arranged below an evaporator, the energy used is controlled within a current limitation of the power supply and air conditioning power (cooling power) can be used efficiently. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a view that schematically illustrates the configuration of an air conditioning device according to an embodiment of the present invention. Fig. Figure 2 is a circuit diagram that schematically illustrates the configuration of the air conditioning device according to the embodiment of the present invention. Fig. Figure 3 is a block diagram that schematically illustrates the configuration of a control device of the air conditioning device according to the embodiment of the present invention. Fig. Figure 4 is a functional block diagram of the control device of the air conditioning device according to the embodiment of the present invention. Fig. Figure 5 is a flowchart illustrating the process of compressor drive control according to the embodiment of the present invention. Fig. Figure 6 is a flowchart illustrating the process of determining the upper operating limit. Fig. Figure 7 is a flowchart illustrating the process of command value setting according to the embodiment of the present invention. Fig. Figure 8 is a flowchart illustrating the process of an assessment procedure for the upper limit according to the embodiment of the present invention. Fig. Figure 9 is a table illustrating setting examples for a speed command value according to the embodiment of the present invention. DESCRIPTION OF THE EXECUTION FORMS
[0010] An embodiment of the present invention is described below with reference to the accompanying figures. Fig. Figures 1 to 9 are examples of carrying out the present invention, wherein parts with the same reference numerals in the figures indicate those with the same function and it is unnecessary to describe them again in the individual figures. <klimatisierungsvorrichtung>
[0011] Fig. Figure 1 is a schematic side view illustrating the basic configuration of an air conditioning device 100 according to an embodiment of the present invention. Fig. Figure 2 is a schematic circuit diagram to explain a refrigerant circuit R of the air conditioning device 100 of the present embodiment.
[0012] Referring to Fig. 1. The air conditioning device 100 uses, for example, a vehicle's cigarette lighter charger as a power supply and is a so-called point cooler (portable cooler) that can, among other things, perform local or individual air conditioning in a passenger compartment or a comparatively small space (hereinafter referred to as "passenger compartment, etc."). The air conditioning device 100 comprises, for example, a condenser 20, a condenser fan 25, a compressor 10, an evaporator 30, an evaporator fan 35, and a [missing information - likely a specific component]. Fig. 1 expansion device (e.g., capillary tubes), not shown, a control device 50, and a housing 60 in which these are received. The housing 60 provides, for example, a discharge opening 61 that conveys air into the passenger compartment, etc., and an exhaust opening 62 for the air conditioning device 100.
[0013] The air conditioning device 100 is designed such that the condenser 20 is arranged vertically below the evaporator 30 in the individual housing body 60, and condensate produced by the evaporator 30 flows down to the condenser 20. Specifically, for example, a tray (not shown) for collecting the condensate and a condensate flow channel (not shown) are provided below the evaporator 30 to redirect the condensate as needed, causing the condensate produced by the evaporator 30 to flow down the surface of the condenser 20 (or its tubes).
[0014] With reference to Fig. In the air conditioning device 100, the compressor 10, the condenser 20, the expansion device 40, and the evaporator 30 are connected by a line 70. A refrigerant circulates in the line 70, forming a refrigerant circuit R in which the refrigerant circulates sequentially through the compressor 10, the condenser 20, the expansion device 40, and the evaporator 30.
[0015] Compressor 10 compresses the refrigerant flowing in line 70. The compressed refrigerant, now a high-pressure gas, is conveyed through line 70 to condenser 20. At condenser 20, the refrigerant liquefies, and after passing through condenser 20, the refrigerant's pressure is reduced at expansion device 40 and it is then conveyed through line 70 to evaporator 30.
[0016] The evaporator 30 is a heat exchanger that forms part of the refrigerant circuit R and facilitates heat exchange between air, which is blown by the evaporator fan 35 through an air intake opening section (not shown) of the housing 60, and the refrigerant in the evaporator 30 itself. The air cooled by the heat exchange is blown out into the passenger compartment, etc., through the outlet opening 61 provided in the housing 60.
[0017] The condenser 20 is a heat exchanger that forms part of the refrigerant circuit R and facilitates heat exchange between air, which is blown in by the condenser fan 25 through an air intake opening section (not shown) of the housing 60, and the refrigerant in the condenser 20 itself. After the heat exchange, the air is expelled through the exhaust opening 62.
[0018] The configuration of the air conditioning device 100 is not based on the example of Fig. 1. As a means of drawing in the air, for example, a single fan common to the condenser 20 and the evaporator 30 may be provided, and the configuration may be such that an airflow channel in the housing 60 branches into a flow channel for flowing into the evaporator 30 and a flow channel for flowing into the condenser 20. A configuration is also possible in which the condenser 20 is covered with a cover or the like, in which a flow channel for the condensate is provided.
[0019] With reference to Fig. 1 and Fig. In the air conditioning device 100 of the present embodiment, the condensate produced by the evaporator 30 flows down the condenser 20. The condensate is moisture in the air blown by the evaporator fan 35, which has cooled due to heat absorption at the evaporator 30. By reusing the condensate through its flow down the condenser 20, the cooling energy of the condensate is absorbed by the condenser 20, thereby promoting the dissipation of heat from the refrigerant flowing in the tubes of the condenser 20. In this way, the cooling efficiency in the refrigerant circuit R can be increased. The heat dissipation at the condenser 20 causes the condensate to evaporate completely or partially.
[0020] In the air conditioning device 100, where, as in the present embodiment, the cooling efficiency can be increased, the cooling capacity can be used efficiently and without waste, particularly in an operating range where the cooling efficiency increases (high-efficiency state of the cooling cycle) and / or in an operating range where the load on the compressor 10 is low. This is described below. <steuervorrichtung>
[0021] Fig. Figure 3 is a block diagram that schematically illustrates the hardware configuration of the control device 50, which controls the air conditioning device 100 across all systems, and the input and output relationship between the control device 50, the air conditioning device 100 and other configuration elements. Fig. Figure 3 extracts the configuration elements relevant for the description of the present embodiment, but the air conditioning device 100 and the control device 50 include, in addition to the configuration elements shown, further known configuration elements, the representation of which is omitted.
[0022] The control device 50 of the present embodiment includes a CPU (Central Processing Unit) 51, memory 52 such as ROM (Read Only Memory) and RAM (Random Access Memory), etc., a non-volatile storage unit 53 such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive), etc., and a communication control unit 54. The CPU 51, the memory 52, the storage unit 53, and the communication control unit 54 are interconnected via an internal bus 55. Various programs are stored in the storage unit 53, beginning with a compressor drive control program described below.
[0023] The control device 50 is connected to, among other things, sensors (detection devices) 80 and an operating section 91, whose outputs are fed into it. The sensors 80 include, among other things, at least one speed sensor 81, which detects the speed of the compressor 10, an outside air temperature sensor 82, which detects the outside air temperature, an evaporator temperature sensor 84, which detects the temperature of the evaporator 30 (temperature of the air flowing through the evaporator 30 or temperature of the evaporator 30 itself), a current sensor 85, which detects the current consumption of the compressor 10, and an outlet temperature sensor 86, which detects the temperature of the air blown out at the outlet opening 61 into the passenger compartment, etc.
[0024] The operating section 91 is designed by a touch panel or the like and includes, for example, operating devices such as an operating switch, a cooling switch and a fan speed switch and display devices such as an operating indicator, a cooling operating indicator, a speed indicator and an error indicator.
[0025] The output of the control device 50, in turn, connects, for example, the compressor 10, the condenser fan 25, and the evaporator fan 35. Based on the outputs of the sensors 80 and the values entered at the operating section 91 (e.g., airflow rate, etc.), the control device 50 controls the individual configuration elements of the air conditioning device 100.
[0026] In Fig. 3. The control device 50 and the sensors 80 can also be formed in one piece, for example by a one-touch microcomputer or the like.
[0027] Fig. Figure 4 is a block diagram illustrating the functional configuration of the control device 50. The control device 50 functions, for example, as a compressor drive control unit 500, which controls the drive of the compressor 10. <verdichterantriebssteuereinheit>
[0028] The compressor drive control unit 500, for example, comprises a state acquisition unit 501, which acquires the outside air environment, the state of the air conditioning device 100 and the compressor 10, and the like; a unit 502 for determining the upper operating limit, which determines an upper operating limit Rrmax, which is an upper limit speed for driving the compressor 10; a unit 503 for determining the speed command value, which determines a command value (speed command value Rc) used for speed control of the compressor 10; and a compressor speed control unit 506, which controls the drive of the compressor 10 based on the speed command value Rc. The compressor drive control unit 500 updates the upper operating limit Rrmax and the speed command value Rc in a fixed cycle (for example, every 10 seconds). <zustandserlangungseinheit>
[0029] The state acquisition unit 501 obtains the output results of, among others, the speed sensor 81, the outside air temperature sensor 82, the evaporator temperature sensor 84, the current sensor 85, and the outlet temperature sensor 86 as the state of the compressor 10. The state acquisition unit 501 obtains these output results by means of a periodic (e.g., once per second) interrupt processing and stores them in the memory unit 53. <Einheit zum Bestimmen des oberen Betriebsgrenzwerts>
[0030] The unit 502 for determining the upper operating limit assesses the load on the compressor 10 according to the state of the compressor 10 achieved by the state acquisition unit 501. The "load on the compressor 10" is a requirement value for the compressor 10 in order to maintain, for example, the temperature (target discharge temperature Ttgt) that is discharged into the space in which the air conditioning device 100 is located, such as the passenger compartment, etc.
[0031] For example, if the ambient outside air is of low temperature and / or low humidity, or if the cooling cycle of the refrigerant circuit R is in a high-efficiency state, or both, the upper operating limit unit 502 judges that the load on compressor 10 is relatively low. A condition with a relatively low load on compressor 10 is referred to below as the "low-load condition".
[0032] However, if, for example, the ambient outside air is of high temperature and / or high humidity, or if the cooling cycle of the refrigerant circuit R is in a low-efficiency state, or both, then the unit 502 for determining the upper operating limit judges that the load on compressor 10 is relatively high. A state with a relatively high load on compressor 10 is referred to below as the "high-load state".
[0033] The load on the compressor 10 can be calculated based on at least one of the outdoor air environment (e.g., outdoor air temperature, outdoor air humidity, etc.), the condition of the air conditioning device 100 (e.g., set blowing strength, condensate production state, etc.) and the condition of the compressor 10 (e.g., power consumption, etc.).
[0034] In the present embodiment, as an example, the high-load or low-load condition is assessed based on the power consumption of the compressor 10. More precisely, the assessment is carried out by calculating the current power consumption of the compressor 10 relative to an upper current limit Irmt of the power supply (cigarette lighter charger). For the current limit Irmt of the power supply (cigarette lighter charger), a fixed value corresponding to the supply voltage (12 V or 24 V) (10 A in this example) is stored in the memory unit 53 of the control device 50.
[0035] The low-load condition is a state in which there is leeway regarding the compressor 10's output and speed control of the compressor 10 is possible, based on the outlet temperature, etc. (prioritizing comfort). In contrast, the high-load condition is a state in which there is a limitation in the speed control of the compressor 10 (comfort is given less priority).More precisely, the high-load state includes a "first high-load state," in which the current power consumption is close to the upper current limit Irmt and control is necessary to maintain the rotational speed so that it does not exceed the current speed of compressor 10 (hereinafter referred to as "current speed Rnow"), and a "second high-load state," in which there is practically no difference (distance) to the upper current limit Irmt and control is necessary to reduce the current speed and thus rapidly lower power consumption. The second high-load state can also be described as an urgent or emergency state.
[0036] Unit 502, used to determine the upper operating limit, calculates a ratio of the current (most recent) power consumption obtained by the state-of-the-art unit 501 to the upper current limit Irmt (ratio of the consumed current to the upper current limit Irmt, hereinafter referred to as the "Irmt ratio"). Threshold values (first threshold and second threshold) are set for the Irmt ratio, based on which the condition of the compressor 10 is assessed.Specifically, if the Irmt ratio is below the first threshold, compressor 10 is deemed to be in low-load mode; if the Irmt ratio is at or above the first threshold and below the second threshold, compressor 10 is deemed to be in the first high-load mode; and if it is at or above the second threshold (up to the upper current limit Irmt), compressor 10 is deemed to be in the second high-load mode. For example, the first threshold is 90% and the second threshold is 95%.
[0037] The unit 502 for determining the upper operating limit determines the upper operating limit Rrmax of the compressor 10 according to the determined load (condition of the compressor 10). Specifically, in the case of the low-load condition, the unit 502 determines the maximum speed of the compressor 10 as the upper operating limit Rrmax. The maximum speed is a fixed value that is preset according to the supply voltage of 12 V or 24 V (stored in the memory unit 53 of the control device 50) and is, for example, 3480 rpm. In the case of the first high-load condition, the unit 502 determines the current speed Rnow as the upper operating limit Rrmax.
[0038] In the case of the second high-load condition, unit 502 uses a speed as the upper operating limit Rrmax for determining the upper operating limit, at which the current speed Rnow has been corrected by a first correction value (it has been subtracted from the current speed Rnow). Since a rapid reduction in speed is necessary in the second high-load condition, the first correction value is, for example, -120 rpm. Thus, in the case of the second high-load condition, unit 502 determines a value as the upper operating limit Rrmax at which 120 rpm have been subtracted from the current speed Rnow. However, if, as a result of correcting the current speed Rnow with the first correction value in the second high-load condition, the compressor 10 speed falls below a minimum value, unit 502 (compressor drive control unit 500) stops the compressor 10.The minimum speed is a fixed value that is preset according to the supply voltage of 12 V or 24 V (stored in the memory unit 53 of the control device 50), and is, for example, 2100 rpm. <Einheit zum Bestimmen des Drehzahlbefehlswerts>
[0039] The unit 503 for determining the speed command value can perform a control in which, in the case that the compressor 10 is in the low load state, it determines a speed command value Rc according to a target discharge temperature Ttgt, an actual discharge temperature Tr detected by the discharge temperature sensor 86 and the current speed Rnow of the compressor 10, and in the case of the high load state, it determines the current speed Rnow or the upper operating limit Rrmax as the speed command value Rc.
[0040] Specifically, unit 503 for determining the speed command value includes a command value setting unit 504 and an evaluation unit 505 for the upper limit. In the case of low-load conditions, the command value setting unit 504 corrects the current speed Rnow according to a difference between the target discharge temperature Ttgt and the actual discharge temperature Tr, based on a defined correction value, and sets a value as the speed command value Rc at which the current speed Rnow is increased, decreased, or maintained. In this case, the correction value is selected from a second correction value (+120 rpm), a third correction value (+60 rpm), a fourth correction value (±0), and a fifth correction value (-60 rpm).
[0041] The target discharge temperature Ttgt is calculated on the basis of the outside air temperature detected by the outside air temperature sensor 82 after calculating a target discharge temperature difference ΔTt using equation 1 or equation 2 below, or using equation 3. At an outside air temperature of 35 °C or below, the target temperature difference ΔTt = outside air temperature − 20 [°C] At an outside air temperature of over 35 °C, the target temperature difference ΔTt = 15 [°C] Target outlet temperature Ttgt = outside air temperature - target outlet temperature difference ΔTt [°C]
[0042] In the case of the first high-load condition, the command value setting unit 504 sets a value based on the actual discharge temperature Tr and the target discharge temperature Ttgt. This value is either reduced by correcting the current speed Rnow using a correction value (for example, a value equal to the fifth correction value), or it sets the current speed Rnow as the speed command value Rc. Specifically, even in the high-load condition, a state can be described in which there is a certain margin regarding the compressor 10's performance if it is determined that the actual discharge temperature Tr is lower than the target discharge temperature Ttgt and the temperature difference between the two is at or above a specified value (for example, 1 °C) (hereinafter referred to as the "first high-load condition (at low temperature)").In this case, a value (reduced current speed Rnow), where the current speed Rnow has been corrected by calculating with the fifth correction value (for example -60 rpm), is set as the speed command value Rc.
[0043] If, on the other hand, it is determined that the difference between the actual discharge temperature Tr and the target discharge temperature Ttgt is small, or that the actual discharge temperature Tr is higher than the target discharge temperature Ttgt (hereinafter referred to as "first high load condition (not at low temperature)"), then a state with little leeway regarding the power of the compressor 10 exists, which is why, in order to maintain the current state, the current speed Rnow is set as the speed command value Rc.
[0044] The command value setting unit 504 determines the upper operating limit Rrmax as the speed command value Rc.
[0045] In the case of low-load conditions and the first high-load condition, the command value setting unit 504 sets the speed command value Rc with the minimum speed of compressor 10 as the lower limit (if necessary, by replacing it with the minimum speed). In the case of the second high-load condition, as discussed above, a comparison with the minimum speed is carried out at unit 502 to determine the upper operating limit.
[0046] The evaluation unit 505 for the upper limit compares the speed command value Rc set by the command value setting unit 504 and the upper operating limit Rrmax and thus finally determines the speed command value Rc with the upper operating limit Rrmax as the upper limit (if necessary by substituting the minimum speed). <verdichterdrehzahlsteuereinheit>
[0047] The compressor speed control unit 506 controls the drive of the compressor 10 based on the speed command value Rc determined by the unit 503 for determining the speed command value. In this example, the compressor 10 is therefore driven with the speed command value Rc, which is updated every 10 seconds. <verdichterantriebssteuerverarbeitung>
[0048] With reference to Fig. Sections 5 to 8 describe an example of the process of compressor drive control carried out by the compressor drive control unit 500. Fig. 5 is a flowchart of the compressor drive control processing sequence, Fig. Figure 6 is a flowchart of the process performed by unit 502 to determine the upper operating limit. Fig. Figure 7 is a flowchart of the sequence of command value setting processing performed by the command value setting unit 504 and Fig. Figure 8 is a flowchart of the process of assessment processing for the upper limit carried out by the assessment unit 505.
[0049] The control device 50 (compressor drive control unit 500) executes the compressor drive control by reading the compressor drive control program from the memory unit 53, opening it in memory 52, and executing it through the CPU 51. The control device 50, among other things, controls the drive of the compressor 10 based on the outputs of the sensors 80, thus operating the air conditioning device 100.
[0050] With reference to Fig. 5. The compressor drive control processing is executed, for example, from the start of operation of compressor 10 in a defined cycle (e.g., every 10 seconds). The state acquisition unit 501 obtains the state of compressor 10 from the output results of, among others, the speed sensing sensor 81, the outside air temperature sensor 82, the evaporator temperature sensor 84, the current sensing sensor 85, and the discharge temperature sensor 86 by means of periodic interrupt processing (e.g., once per second) and stores these values in the storage unit 53.
[0051] First, in step S101, the compressor drive control unit 500 obtains the current power consumption. This consumption is periodically obtained by the state acquisition unit 501 as an output from the current sensing sensor 85 and stored in the memory unit 53. In the next step, S103, the compressor drive control unit 500 obtains the current rotational speed Rnow. This current rotational speed Rnow is also periodically obtained by the state acquisition unit 501 as an output from the rotational speed sensing sensor 81 and stored in the memory unit 53.
[0052] In step S105, the processing to determine the upper operating limit is performed, in which the upper operating limit Rrmax is determined according to the Irmt ratio (compressor state 10). In step S107, the command value setting processing is performed, in which the speed command value Rc is (provisionally) set according to the target discharge temperature Ttgt and the actual discharge temperature Tr. In step S109, the evaluation processing for the upper limit is performed. In the evaluation processing for the upper limit, the speed command value Rc set in step S107 and the upper operating limit Rrmax are compared, and the speed command value Rc is finally determined.
[0053] In the next step S111, the compressor speed control unit 506 controls the drive of the compressor 10 based on the speed command value Rc determined by the unit 503 to determine the speed command value, thus ending the processing. <Verarbeitung zum Bestimmen des oberen Betriebsgrenzwerts>
[0054] Fig. Figure 6 is a flowchart that shows an example of the processing sequence for determining the upper operating limit from step S105. Fig. Figure 5 illustrates this. The processing to determine the upper operating limit is performed, for example, by the upper operating limit determination unit 502.
[0055] In step S201 of the processing to determine the upper operating limit, unit 502 obtains the upper current limit Irmt of the power supply (cigarette lighter charger). In step S203, it calculates the current power consumption of compressor 10 in relation to the upper current limit Irmt (ratio of current power consumption to upper current limit Irmt). In this example, the current power consumption is used in step S101 of the compressor drive control processing ( Fig. 5) obtained.
[0056] In step S205, it is assessed whether the Irmt ratio is at or above the second threshold (95% in this example), and if it is below the second threshold, a transition to step S207 takes place, while if it is at or above the second threshold, a transition to step S213 takes place.
[0057] In step S207, it is assessed whether the Irmt ratio is at or above the first threshold (90% in this example), and if it is below the first threshold, a transition to step S209 takes place, while if it is at or above the first threshold, a transition to step S211 takes place.
[0058] Step S209 is the step that proceeds when compressor 10 is in the low-load state. In this case, the preset maximum speed (in this example, the fixed value of 3480 rpm) is determined as the upper operating limit Rrmax.
[0059] Step S211 is the step that proceeds when the state of compressor 10 is the first high-load state. In this case, the compressor drive control processing in step S103 ( Fig. 5) The current rotational speed Rnow is determined as the upper operating limit Rrmax.
[0060] In step S213, which is continued if the Irmt ratio is at or above the second threshold in step S205 (i.e., in the second high-load state), a value is set as the upper operating limit Rrmax, where the current speed Rnow has been corrected (compensated) by the first correction value (-120 rpm). The upper operating limit Rrmax is therefore a value where 120 rpm has been subtracted from the current speed Rnow.
[0061] In step S215, it is assessed whether the upper operating limit Rrmax set in step S213 is at or below the minimum speed. If it is at or below the minimum speed, the process proceeds to step S217, while processing terminates if it is above the minimum speed. In step S217, a compressor shutdown process is performed. The compressor shutdown process is separate from the compressor drive control process, the details of which are not explained. After compressor 10 stops, a restart is performed after a predetermined time has elapsed, according to a timer control or similar mechanism.
[0062] Fig. 7 is a flowchart that shows an example of the command value setting processing sequence of step S107 of the compressor drive control processing ( Fig. 5). Illustrated. For example, command value setting processing is performed by the command value setting unit 504.
[0063] In step S301 of the command value setting process, the command value setting unit 504 obtains the outside air temperature and calculates the target outlet temperature difference ΔTt. The outside air temperature is obtained as an output from the outside air temperature sensor 82 by the state acquisition unit 501 and stored in the storage unit 53. The target outlet temperature difference ΔTt is calculated according to the outside air temperature using either Equation 1 or Equation 2. In step S303, the command value setting unit 504 calculates the target outlet temperature Ttgt using Equation 3.
[0064] In step S305, the actual outlet temperature Tr (temperature of the air at the outlet opening 61) is obtained. The actual outlet temperature Tr is obtained by the state acquisition unit 501 as an output from the outlet temperature sensor 86 and stored in the storage unit 53.
[0065] In step S307, it is assessed whether the actual outlet temperature Tr is equal to or greater than "target outlet temperature Ttgt+1 °C", and if it is less than "target outlet temperature Ttgt+1 °C", a transition to step S309 occurs, while a transition to step S323 occurs if it is equal to or greater than "target outlet temperature Ttgt+1 °C".
[0066] In step S309, it is assessed whether the actual outlet temperature Tr is less than the target outlet temperature Ttgt+1 °C and equal to or greater than the target outlet temperature Ttgt. If so, the process proceeds to step S321; otherwise (if it is below the target outlet temperature Ttgt), it proceeds to step S311. In step S311, it is assessed whether the actual outlet temperature Tr is less than the target outlet temperature Ttgt and greater than the target outlet temperature Ttgt-1 °C. If so, it proceeds to step S313; otherwise (if it is equal to or less than the target outlet temperature Ttgt-1 °C), it proceeds to step S315.
[0067] In step S313, which is continued if the assessment in step S311 is “Yes” (the actual discharge temperature Tr is lower than the target discharge temperature Ttgt, but the difference between the two is relatively small), the value of the current rotational speed Rnow is set to the rotational speed command value Rc (a correction is performed with the fourth correction value (±0)), thus ending the processing.
[0068] In step S315, which is continued if the assessment in step S311 is "No" (the actual outlet temperature Tr is lower than the target outlet temperature Ttgt and the difference between the two is of a certain magnitude), a value where the current speed Rnow has been corrected (calculated) by the fifth correction value (-60 rpm) is set as the speed command value Rc. In other words, a value where 60 rpm has been subtracted from the current speed Rnow is set as the speed command value Rc.
[0069] In step S317, it is assessed whether the speed command value Rc set in step S315 falls below the minimum speed, and if it does, a transition to step S319 takes place, while processing ends if it does not fall below it.
[0070] In step S319, the speed command value Rc is reset to the minimum speed (replaced by the minimum speed), thus ending the processing.
[0071] In step S321, which is continued if the assessment in step S309 is "Yes" (the actual outlet temperature Tr is equal to or greater than the target outlet temperature Ttgt and the difference between the two is relatively small), a value where the current speed Rnow has been corrected (calculated) by the third correction value (+60 rpm) is set as the speed command value Rc. In other words, a value where 60 rpm has been added to the current speed Rnow is set as the speed command value Rc.
[0072] In step S323, which is continued if the assessment in step S307 is "Yes" (the actual outlet temperature Tr is higher than the target outlet temperature Ttgt and the difference between the two is relatively large), a value where the current speed Rnow has been corrected (calculated) by the second correction value (+120 rpm) is set as the speed command value Rc. In other words, a value where 120 rpm has been added to the current speed Rnow is set as the speed command value Rc.
[0073] Fig. Figure 8 is a flowchart that shows an example of the assessment processing flow for the upper bound of step S109 of the compressor drive control processing ( Fig. 5). Illustrated. For example, the assessment processing for the upper limit is carried out by the assessment unit 505 for the upper limit.
[0074] In step S401, the command value setting process ( Fig. 7) The set speed command value Rc is compared to the upper operating limit Rrmax. If the speed command value Rc is at or above the upper operating limit Rrmax, the process transitions to step S403 and the speed command value Rc is reset to (replaced with) the upper operating limit Rrmax. If the speed command value Rc is below the upper operating limit Rrmax, this speed command value Rc is retained and processing ends.
[0075] In the exemplary sequence of the present embodiment, even in the case of the second high-load condition, the speed command value Rc is determined by the command value setting processing. Fig. 7 temporarily changed according to the actual discharge temperature Tr and the target discharge temperature Ttgt, but ultimately, regardless of the difference between the actual discharge temperature Tr and the target discharge temperature Ttgt, the upper operating limit Rrmax is determined by the evaluation unit 505 as the speed command value Rc for the upper limit.
[0076] Fig. Table 9 is a table that provides an overview of an example of speed command values Rc determined as a result of compressor drive control processing.
[0077] In the present embodiment, the current rotational speed Rnow is corrected and the rotational speed command value Rc is set only in the case of the low-load condition (Irmt ratio < 90%) and the first high-load condition (at low temperature), i.e., in the first high-load condition (90% ≤ Irmt ratio < 95%) at low temperature (actual discharge temperature Tr ≤ target discharge temperature Ttgt - 1 °C) by means of a temperature-correcting value. Thus, a rotational speed command value Rc is set where comfort takes priority. Specifically, the rotational speed command value Rc in the low-load condition (Irmt ratio < 90%) is set by steps S313, S315, S321, and S323 of the command value setting process ( Fig. 7) according to the difference between the actual discharge temperature Tr and the target discharge temperature Ttgt. In the first high-load condition (at low temperature), the speed command value Rc is set based on step S315 (according to the difference between the actual discharge temperature Tr and the target discharge temperature Ttgt). The low-load condition is a state with leeway regarding the compressor 10's power output, and the first high-load condition (at low temperature), while a high-load condition, has a relatively low actual discharge temperature Tr (lower than the target discharge temperature Ttgt, and the difference between the two is large), thus providing leeway for reducing the speed. In these cases, the current speed Rnow is corrected according to the difference between the actual discharge temperature Tr and the target discharge temperature Ttgt and used as the speed command value Rc.
[0078] In contrast, in the Fig. 9. The first high-load state (not at low temperature), shaded in gray, is the first high-load state where the actual discharge temperature Tr is higher than the "target discharge temperature Ttgt-1 °C". In the second high-load state, the temperature correction result is "None", and the upper operating limit Rrmax or the current speed Rnow (in the first high-load state (not at low temperature), the same value as the upper operating limit Rrmax) is used as the speed command value Rc. Specifically, the speed command value Rc in the first high-load state (not at low temperature) and the second high-load state is indeed set by step S321 or step S323 of the command value setting process ( Fig. 7) set, but the speed command value Rc is set due to the evaluation processing for the upper limit ( Fig. 8) is replaced by the upper operating limit Rrmax. Ultimately, no correction (control of the current speed Rrnow according to the temperature) is carried out, but the speed command value Rc is determined based on the current consumption (Irmt ratio).
[0079] Consequently, in high-load conditions (first high-load conditions or second high-load conditions), the compressor 10 can be operated at its maximum speed within the range where the usable power of the power supply (cigarette lighter charger) is not exceeded, thus ensuring sufficient cooling capacity. In low-load conditions (normal conditions), on the other hand, the compressor 10 can be operated at a speed that results in the most comfortable discharge temperature (i.e., reduces the difference between the target discharge temperature Ttgt and the actual discharge temperature Tr).
[0080] According to the foregoing, in the present embodiment, different control is carried out in the low-load state (and also in the high-load state in the range with leeway regarding the power of the compressor 10) and in the high-load state (in the range without leeway regarding the power of the compressor 10, gray shaded area). As long as it is ultimately a configuration in which, as in Fig. As shown in Figure 9, different control is carried out in a state with leeway regarding the power of the compressor 10 (for example, in the low-load state and in the high-load state at low temperature) and in a state without leeway regarding the power of the compressor, there is no restriction on the processing processes. Fig. 5 to 8 before.
[0081] In the embodiment described above, the normal and high-load states of compressor 10 are assessed based on a threshold value derived from power consumption (Irmt ratio). However, there is no limitation to this, and the outside air temperature and / or humidity can also be measured, and the assessment made based on these and the power consumption to determine low load and high efficiency. For example, the assessment can be made, among other things, such that if the temperature is at or below a threshold value and / or the humidity is at or below a threshold value and the Irmt ratio is at or below a threshold value, the normal state is determined to be present.
[0082] The air conditioning device 100 does not need to be configured in such a way that condensate generated at the evaporator 30 flows down to the condenser 20 and the cooling energy of the condensate is recovered at the condenser 20 (the condensate is reusable).
[0083] The values listed above for the first through fifth correction values are examples and are not limited to these. In the embodiment described above, the correction value for the first high-load condition (at low temperature) is set to the same value as the fifth correction value, but it could also be a different value. Similarly, the values listed above for the first and second threshold values are examples, and other values could be used.
[0084] The air conditioning device 100 of the present invention is not limited to the embodiment described above, but can of course be modified in different ways without deviating from the scope of the present invention. LIST OF REFERENCE MARKS 10 compressors 20 Capacitor 25 condenser fans 30 evaporators 35 evaporator fans 40 Expansion device 50 Control device 51 CPU 52 storage 53 storage units 54 Communication control unit 55 internal bus 60 Housing bodies 61 Exhaust opening 62 Exhaust opening 70 Management 80 sensors (detection devices) 81 Speed detection sensor 82 Outdoor air temperature sensor 84 Evaporator temperature sensor 85 Current sensing sensor 86 Outlet temperature sensor 91 Operating section 100 air conditioning unit 500 Compressor drive control unit 501 State recovery unit 502 Unit for determining the upper operating limit 503 Unit for determining the speed command value 504 Command Value Setting Unit 505 Assessment unit for the upper limit 506 Compressor speed control unit Irmt upper current limit RC speed command value Now current speed Rrmax upper operating limit Tr Actual outlet temperature Ttgt Target outlet temperature ΔTt Target outlet temperature difference< / verdichterantriebssteuerverarbeitung> < / verdichterdrehzahlsteuereinheit> < / zustandserlangungseinheit> < / verdichterantriebssteuereinheit> < / steuervorrichtung> < / klimatisierungsvorrichtung>
Claims
[1] Air conditioning device comprising a housing body in which a refrigerant circuit with a compressor, a condenser, a pressure reducing device and an evaporator and a control device are included, characterized by , that the control device comprises a unit for determining the upper operating limit, a unit for determining the speed command value and a compressor speed control unit, wherein the unit for determining the upper operating limit performs a control to determine an upper operating limit according to a load on the compressor, which is an upper speed limit for driving the compressor, wherein the unit for determining the speed command value can perform a control in which, in the case of a relatively low load, it determines a speed command value according to a setpoint discharge temperature and a current speed of the compressor (hereinafter referred to as "current speed") and, in the case of a relatively high load, determines the current speed or the upper operating limit as the speed command value, the compressor speed control unit controls the drive of the compressor based on the speed command value. [2] Air conditioning device according to claim 1, characterized by, that the unit for determining the upper operating limit assesses the compressor's state to determine whether it is in a state of relatively low load (hereinafter referred to as the "low load state"), a first state of relatively high load (hereinafter referred to as the "first high load state"), and a second state of relatively high load in which there is a need to reduce power consumption (hereinafter referred to as the "second high load state"), and determines the upper operating limit on the basis of the assessed state. [3] Air conditioning device according to claim 2, characterized by , that the unit for determining the upper operating limit in the case of low load conditions uses a maximum compressor speed as the upper operating limit, In the case of the first high-load condition, the current speed is used as the upper operating limit and In the case of the second high-load condition, a reduced speed compared to the current speed is used as the upper operating limit. [4] Air conditioning device according to claim 2, characterized by , that the unit for determining the speed command value in the case of the low load condition sets a value at which the current speed has been increased or maintained according to a difference between the target discharge temperature and an actual discharge temperature as the speed command value. [5] Air conditioning device according to claim 2, characterized by , that the unit for determining the speed command value, if in the case of the first high-load condition it is judged that the actual discharge temperature is low, reduces the current speed, and if it is judged that it is not low, sets the current speed as the speed command value. [6] Air conditioning device according to claim 2, characterized by, that the unit for determining the speed command value in the case of the second high load condition determines the upper operating limit as the speed command value. [7] Air conditioning device according to claim 4 or 5, characterized by , that the unit for determining the speed command value determines the speed command value using the upper operating limit as the upper limit. [8] Air conditioning device according to claim 2, characterized by , that the control device stops the compressor if the upper operating limit determined in the case of the second high load condition falls below a minimum compressor speed. [9] Air conditioning device according to claim 2, characterized by , that the unit for determining the speed command value, if the speed command value set in the case of the first high load condition or the low load condition falls below a minimum compressor speed, determines the minimum speed as the speed command value. [10] Air conditioning device according to claim 1, characterized by , that it is designed in such a way that the condenser is located below the evaporator and condensate produced by the evaporator is allowed to flow down to the condenser.