Vehicle air conditioning device provided with heating control device and control program

Abstract

The present disclosure aims to provide a heating control device, a heating cycle device, and a vehicle air conditioning device equipped with the heating cycle device, which can perform control with a small temperature variation with respect to a target temperature while reaching the target temperature in advance. The heating control device 6 of the present disclosure controls a transistor 5 that supplies power to a heater 4 that heats a coolant, in which the heating control device adjusts a heating amount of the heater according to a heating amount control curve that has a reduction portion in which the heating amount decreases as the temperature of the coolant increases, the reduction portion has a first reduction portion and a second reduction portion, both the first reduction portion and the second reduction portion have a negative slope, and the first reduction portion and the second reduction portion have equal heating amounts at a target temperature, the first reduction portion has a first region and a second region, and the slope at any temperature in the second region is greater than the slope at any temperature in the first region.

Description

Technical Field

[0001] This disclosure relates to a heating control device and control program, a fluid heating unit, a heating circulation device, and a vehicle air conditioning unit equipped with the heating circulation device. Background Technology

[0002] Previously, a vehicle air conditioning system using a warm water heating device (see, for example, Patent Document 1) was known. In the vehicle air conditioning system of Patent Document 1, a first switch and a second switch are provided. By setting the target temperature of the warm water when the second switch is activated to a value lower than the target temperature of the warm water when the first switch is activated, a comfortable heating temperature can be obtained when the temperature inside the vehicle is high.

[0003] Furthermore, as a heater for a hot water heating device, a fluid heating unit that uses an electric heater to heat the fluid is disclosed (for example, see Patent Document 2).

[0004] As a method for controlling the power supply of a counter-current electric heater, a method is known for using an inverter to control the duty cycle of DC power obtained from a battery and supply it (see, for example, Patent Document 3).

[0005] Patent Document 1: Japanese Patent Application Publication No. 10-258630 Patent Document 2: Japanese Patent Application Publication No. 2017-215084 Patent Document 3: Japanese Patent Application Publication No. 2003-335127 Summary of the Invention The technical problem that the invention aims to solve

[0006] In recent years, electric vehicles (EVs) that run solely on electric motors, hybrid electric vehicles (HEVs) that run on multiple power sources including electric motors and internal combustion engines, and vehicles that run on electric motors using electricity generated by internal combustion engines have become increasingly popular.

[0007] In the case of electric vehicles, since there is no engine, the total coolant volume in the coolant circuit is less than that of vehicles with an engine, requiring only 10 liters. The coolant flow rate in the coolant circuit is approximately 10 liters per minute. Although the actual flow rate may vary, all the fluid circulates in less than one minute. Therefore, when temperature fluctuations occur at the outlet of the fluid heating unit, the impact of these fluctuations is more likely to spread throughout the entire path due to the smaller total coolant volume. This necessitates more stringent temperature control and stabilization compared to vehicles with an engine.

[0008] Furthermore, in the case of hybrid vehicles or vehicles that, although they have an internal combustion engine, are powered by an electric motor, while the total coolant volume is greater than that of electric vehicles, there is a requirement to reduce the coolant volume to lighten the overall vehicle weight, thus the total coolant volume tends to be reduced. Therefore, if temperature fluctuations occur at the heater outlet, the effects will also affect the entire path.

[0009] For example, in the vehicle air conditioning device of Patent Document 1 Figure 2 In the past, the temperature variation of warm water was controlled to be ±5°C relative to the target temperature. However, in vehicles with a smaller total coolant volume, it is required that the temperature variation be even smaller, for example, ±1°C relative to the target temperature.

[0010] The purpose of this disclosure is to provide a heating control device and control program, a fluid heating unit, a heating circulation device, and a vehicle air conditioning unit equipped with the heating circulation device, which can achieve the target temperature in advance and have small temperature fluctuations relative to the target temperature. Technical solutions for solving technical problems

[0011] The heating control device of the present invention controls a transistor that supplies power to a heater via a switching action. The heater generates heat by being energized and heats the coolant supplied to the radiator of a vehicle air conditioning unit. The heating control device is characterized in that it controls the switching action of the transistor based on a heating amount control curve, changing the on-off duty cycle of the transistor to adjust the heating amount of the heater. The heating amount control curve is a function representing the relationship between the temperature of the coolant and the heating amount of the heater, and it exhibits a decrease in heating amount as the temperature rises from a low-temperature side to a high-temperature side above the target temperature of the coolant. The reduction portion has a first reduction portion when the temperature is in a temperature range below the target temperature and a second reduction portion when the temperature is in a temperature range above the target temperature, and the first reduction portion and the second reduction portion have equal heating amounts at the target temperature. Both the first reduction portion and the second reduction portion have negative slopes in the function. The first reduction portion has a first region and a second region that is closer to the high temperature side than the first region. The slope of the heating amount control curve at any temperature in the second region is more negative than the slope of the heating amount control curve at any temperature in the first region.

[0012] The heating control device of the present invention includes the following scheme: the reduction part is a curve with an inflection point, and the temperature at the inflection point is consistent with the target temperature.

[0013] The heating control device of the present invention includes the following scheme: the reduction part is a curve with an inflection point, and the temperature at the inflection point is higher than the target temperature.

[0014] The heating control device of the present invention includes the following scheme: the reduction section is a curve with an inflection point, the temperature at the inflection point is lower than the target temperature, and the second region is located in a region closer to the low temperature side than the inflection point.

[0015] The heating control device of the present invention includes the following scheme: the first region and the second region are both linear functions with different slopes in the function.

[0016] The heating control device of the present invention includes the following scheme: the reduction part is a curve without an inflection point.

[0017] The heating control device of the present invention includes the following scheme: the heating amount control curve has a constant portion at a lower temperature side than the first reduction portion, in which the heating amount remains constant even though the temperature rises from the lower temperature side to the higher temperature side.

[0018] In the heating control device of the present invention, it is preferable that the second reducing part has a heat dissipation area corresponding to the heat amount that maintains the heating amount at a predetermined heating amount on the side higher than the target temperature.

[0019] The fluid heating unit of the present invention is characterized by comprising a heater that generates heat by being energized and heats the coolant, a transistor that supplies power to the heater by a switching action, and a heating control device of the present invention, which controls the switching action of the transistor.

[0020] The heating circulation device of the present invention is characterized by comprising a circulation path, a coolant filled in the circulation path, a pump for circulating the coolant in the circulation path, a fluid heating unit of the present invention for adjusting the temperature of the coolant, and a radiator for dissipating heat from the coolant, wherein the coolant is heated in the fluid heating unit by energizing the heater using the transistor.

[0021] The vehicle air conditioning unit of the present invention is mounted on a vehicle and includes the heating circulation device of the present invention. The vehicle is characterized in that it is capable of motor-driven operation, the vehicle air conditioning unit has a temperature regulating unit for regulating the temperature of the air supplied to the vehicle interior, and the radiator is a hot water heat exchanger disposed inside the temperature regulating unit.

[0022] The control program of the present invention is characterized in that it enables the heating control device of the present invention to perform a control process that controls the switching action of the transistor based on the heating amount control curve. The effects of the invention

[0023] According to this disclosure, a heating control device and control program, a fluid heating unit, a heating circulation device, and a vehicle air conditioning unit equipped with the heating circulation device can be provided, which are capable of controlling the temperature to reach the target temperature in advance and with small temperature fluctuations relative to the target temperature. Attached Figure Description

[0024] Figure 1 This is a block diagram illustrating an example of a fluid heating unit, a heating circulation device, and a vehicle air conditioning unit equipped with the heating circulation device according to this embodiment. Figure 2 This is a graph representing the first example of a heating control curve. Figure 3 This is a graph representing the second example of a heating control curve. Figure 4 This is the third example of a heating control curve. Figure 5 This is the fourth example of a heating control curve. Figure 6 This is the fifth example of a heating control curve. Figure 7 This is a graph representing the first example of a curve excluded from the heating control curve. Figure 8 This is a graph representing the second example of a curve excluded from the heating control curve. Figure 9 This is a graph representing the third example of a curve excluded from the heating control curve. Figure 10 This is the fourth example of a curve excluded from the heating control curve. Figure 11 The diagram shows an example of duty cycle control for a heating cycle device. (a) shows duty cycle control in the constant section, (b) shows duty cycle control at any temperature in the reducing section, and (c) shows duty cycle control at any temperature in the region corresponding to the heat dissipation. Figure 12 This is a graph showing the relationship between heating time and coolant temperature in Example 1. Figure 13 This is a graph showing the relationship between heating time and coolant temperature in Comparative Example 1. Figure 14 This is a graph showing the relationship between heating time and coolant temperature in Comparative Example 2. Detailed Implementation

[0025] Hereinafter, one aspect of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to these embodiments. It should be noted that the same reference numerals in this specification and the accompanying drawings denote the same elements. Various modifications can be made to achieve the desired effect of the present invention.

[0026] Figure 1 This is a block diagram illustrating an example of the heating circulation device of this embodiment and a vehicle air conditioning unit equipped with the heating circulation device. The heating control device 6 of this embodiment controls a transistor 5 that supplies power to a heater 4 via a switching operation. The heater 4 heats up when energized and heats the coolant supplied to the radiator 7 mounted on the vehicle air conditioning unit 900. The heating control device 6 is based on… Figures 2 to 6 The heating control curve 100 (100A~100E) shown is used to control the switching action of transistor 5, changing the on-off duty cycle of transistor 5 to adjust the heating amount of heater 4. The heating control curve 100 (100A~100E) is as follows: Figures 2 to 6 As shown, the function represents the relationship between the coolant temperature T and the heater heating amount E, and has a reduction section 110 where the heating amount E decreases as the coolant temperature Tt increases from the low temperature side to the high temperature side across the coolant temperature range Tt. The reduction section 110 has a first reduction section 111 when the temperature T is below the target temperature Tt and a second reduction section 112 when the temperature T is above the target temperature Tt. The first reduction section 111 and the second reduction section 112 have equal heating amounts E at the target temperature Tt. Both the first reduction section 111 and the second reduction section 112 have negative slopes in the function. The first reduction section 111 has a first region 111A and a second region 111B that is closer to the high temperature side than the first region 111A. The slope of the heating amount control curve 100 (100A~100E) at any temperature in the second region 111B is more negative than the slope of the heating amount control curve 100 (100A~100E) at any temperature in the first region 111A.

[0027] The fluid heating unit 10 of this embodiment includes a heater 4 that heats up by being energized and heats the coolant, a transistor 5 that supplies power to the heater 4 by switching on and off, and a heating control device 6 of this embodiment, which controls the switching on and off of the transistor 5.

[0028] The fluid heating unit 10 supplies power to the heater 4 via the transistor 5, and the heater 4 heats up to heat the coolant supplied to the radiator 7 of the vehicle's air conditioning system. At this time, the heating control device 6 controls the switching action of the transistor 5 based on the heating amount control curve 100 (100A~100E), changes the on-off duty cycle of the transistor 5 to adjust the heating amount of the heater 4, thereby regulating the temperature of the coolant.

[0029] The heating circulation device 1 of this embodiment includes a circulation path 2, a coolant filled in the circulation path 2, a pump 3 for circulating the coolant in the circulation path 2, a fluid heating unit 10 of this embodiment for adjusting the temperature of the coolant, and a radiator 7 for dissipating heat from the coolant. The coolant is heated in the fluid heating unit 10 by energizing the heater 4 using a transistor 5.

[0030] The heating circulation device 1 is a device in a vehicle air conditioning system that generates warm air for heating by exchanging heat between the coolant, which is regulated by the fluid heating unit 10, and the air passing through the radiator 7.

[0031] The circulation path 2 includes a pipe 12 connecting the coolant outlet of the radiator 7 to the pump 3, and a pipe 13 connecting the pump 3 to the tank inlet 10b. The coolant is supplied via a pipe 11 connecting the outlet 10a of the tank (not shown) housing the heater 4 to the coolant inlet of the radiator 7, and then via pipe 13 from the inlet 10b into the heating chamber within the tank (not shown), where it is heated by the heater 4 built into the tank. The heated coolant is then discharged from the tank outlet 10a, supplied through pipe 11 to the radiator 7, dissipating heat and warming the air for air conditioning. The coolant that has passed through the radiator 7 is drawn into the pump 3 via pipe 12 for circulation.

[0032] Coolant (not shown) is liquid at room temperature, for example, a heat medium in which ethylene glycol or glycerol is dissolved in water.

[0033] The fluid heating unit 10, like the fluid control unit described in Patent Document 2, includes a heater 4, a tank (not shown) for housing the heater 4, and a transistor 5 disposed on the upper wall of the tank.

[0034] The heater 4 is an electric heating element that generates heat by energizing an electrical source, and is not particularly limited to any particular type; for example, a heater with a sheath consisting of a nichrome wire encased in a metal tube can be used. The tank has a heating chamber for the flow of coolant and for housing the heater 4. The heating chamber receives the coolant before heating through an inlet 10b and discharges the heated coolant through an outlet 10a. Preferably, the heating chamber has a temperature sensor 50 near the outlet 10a to detect the temperature T of the heated coolant. More preferably, the temperature sensor 50 is located at the outlet 10a.

[0035] Transistor 5 is preferably, for example, an Insulated Gate Bipolar Transistor (IGBT). Transistor 5 is electrically connected to battery 8. Furthermore, transistor 5 is electrically connected to control device 6 and performs switching operations according to command signals from heating control device 6. Transistor 5 controls the power supply to heater 4 through switching operations. By changing the on-off duty cycle of transistor 5, the heating amount of heater 4 can be adjusted, and the heat acting on the coolant can be regulated. The fluid heating unit 10 is configured to include at least heater 4, transistor 5, heating control device 6, and electrical wiring 51 connecting them and forming a circuit with battery 8.

[0036] The heating control device 6 controls the switching action of the transistor 5 based on the heating amount control curve 100 (100A~100E).

[0037] The control program of this embodiment enables the heating control device 6 of this embodiment to perform control processing for switching operations of the transistor 5 based on the heating amount control curve (100 (100A~100E)). The heating control device 6 has a storage unit (not shown) and functions as a heating control device by executing the control program read from the storage unit. The execution of the control program includes, for example, the following steps. First, the current temperature T of the coolant is detected, and the "heating amount E of the heater 4" corresponding to the current temperature T is read by applying the heating amount control curve (100 (100A~100E)). Next, as Figure 11 Transistor 5 is controlled in such a way that duty cycle control is implemented to provide heater 4 with "heating amount E corresponding to the current temperature T".

[0038] Radiator 7 is a hot water heat exchanger.

[0039] The temperature sensor 50 can also be installed in the circulation loop 2 instead of the fluid heating unit 10, in the piping 11 that connects the outlet 10a of the tank (not shown) housing the heater 4 to the inlet of the coolant in the radiator 7.

[0040] Heating control curve 100 (100A~100E) is as follows Figures 2 to 6 As shown, this is a function representing the relationship between the coolant temperature T and the heater's heating capacity E. Figures 2 to 6 In the diagram, the heating control curves 100 (100A~100E) are plotted with the coolant temperature T on the horizontal axis and the heating amount E of the heater 4 on the vertical axis. The coolant temperature T is preferably, for example, the temperature of the coolant discharged from the outlet 10a of the fluid heating unit 10, and the unit is, for example, °C. The heating amount E of the heater 4 is, for example, a value that is adjusted by using the on-off duty cycle of the transistor 5, and the unit is, for example, KW / h.

[0041] The reduction section 110 is the part where the heating amount E decreases as the temperature T rises from the low-temperature side to the high-temperature side across the target temperature Tt of the coolant. The reduction section 110... Figures 2 to 6 The temperature range is defined as the temperature from T1, where the heating amount E begins to decrease, to Te, where the heating amount E approaches zero or reaches zero (not shown). The starting temperature T1 of the decreasing section 110 is preferably {target temperature Tt} - 10°C, more preferably {target temperature Tt} - 8°C. The target temperature Tt is, for example, 80~85°C.

[0042] The first reduction section 111 is the temperature range in the reduction section 110 from the temperature T1 at which the heating amount E begins to decrease to below the target temperature Tt. The first reduction section 111 has a first region 111A and a second region 111B that is closer to the higher temperature side than the first region 111A. The boundary between the first region 111A and the second region 111B is not particularly defined. Figure 2 In this example, let's say the temperature T3 is the temperature that divides the range between the starting temperature T1 of the reduction section 110 and the target temperature Tt into two equal parts, but it can be any temperature.

[0043] The second reduction section 112 is the temperature range above the target temperature Tt in the reduction section 110 and up to the temperature Te where the heating amount E is infinitely close to zero or the temperature where the heating amount E becomes zero (not shown).

[0044] like Figures 2 to 6 As shown, the first reducing section 111 and the second reducing section 112 have equal heating amounts E at the target temperature Tt. Therefore, as Figure 7 or Figure 8 As shown, curves 200 and 201, which indicate a decrease in heating amount at the target temperature Tt, are excluded from the heating amount control curve 100. Figure 7 It is a simple on / off control. Figure 8 for Figure 7 A variation. In Figure 7 or Figure 8 In curves 200 and 201, the heating amount E decreases sharply at the target temperature Tt, resulting in a larger temperature variation relative to the target temperature. This is because the coolant is dissipated by the radiator 7. Although the temperature rises to the target temperature Tt, the heating amount suddenly becomes "zero," and the coolant temperature T drops sharply from the target temperature.

[0045] like Figures 2 to 6As shown, both the first reduction portion 111 and the second reduction portion 112 have negative slopes in the function, and the slope of the heating amount control curve 100 (100A~100E) at any temperature within the second region 111B is more negative than the slope of the heating amount control curve 100 (100A~100E) at any temperature within the first region 111A. Therefore, the target temperature can be reached earlier, and temperature fluctuations relative to the target temperature can be reduced. For example, Figure 9 As shown, the slope of curve 202 in the first decreasing part 111 remains constant. Figure 10 As shown, curve 203, whose slope at any temperature within the second region 111B is less negative than the slope at any temperature within the first region 111A, is excluded from the heating control curve 100. In these... Figure 9 or Figure 10 As shown in curves 202 and 203, the heating rate slows down, and the target temperature cannot be reached in advance.

[0046] In the heating circulation device of this embodiment, such as Figures 2 to 6 As shown, the following scheme is included: the heating amount control curve 100 (100A~100E) has a constant part 120 at the low temperature side compared to the first reduction part 111, where the heating amount E remains constant even though the temperature T rises from the low temperature side to the high temperature side.

[0047] In the heating circulation device of this embodiment, such as Figures 2 to 6 As shown, the second reducing section 112 preferably has a heat dissipation corresponding region 112A at a higher temperature side than the target temperature Tt, which maintains the heating amount E at a predetermined heating amount. The heat dissipation corresponding region 112A is a region where the heating amount E is close to zero but not zero. At the end of the heat dissipation corresponding region 112A, Te is more preferably {target temperature Tt + 8°C} ± 1°C. At the beginning of the heat dissipation corresponding region 112A, T2 is preferably, for example, {target temperature Tt + 4°C} ± 1°C. If heat is dissipated in the radiator 7 and the temperature rises beyond the target temperature Tt but suddenly becomes "zero", the coolant temperature T will be lower than the target temperature, causing temperature fluctuations. By setting the heat dissipation corresponding region 112A, temperature fluctuations can be suppressed.

[0048] In the heating control curve 100 (100A~100E), the temperature T at which the heating amount E becomes 0 is preferably 90°C. If it exceeds 90°C, adverse conditions may occur, such as the unexpected precipitation of dissolved components in the coolant or a decrease in heat conduction caused by bubbles at the interface between the coolant and the heat transfer wire.

[0049] Next, examples of each heating control curve 100 (100A~100E) will be explained in more detail.

[0050] Figure 2 This is a graph showing the first example of a heating quantity control curve. In the heating cycle apparatus of this embodiment, as... Figure 2 As shown, the scheme includes the following: the reduction unit 110 is a curve with an inflection point P, where the temperature T at the inflection point P coincides with the target temperature Tt. The heating quantity control curve 100 (100A) of the first example can reach the target temperature Tt within, for example, 15 minutes and control the temperature relative to the target temperature Tt within, for example, the range of {target temperature Tt} ± 1°C. Furthermore, since the temperature T at the inflection point P coincides with the target temperature Tt, the temperature fluctuation relative to the target temperature Tt can be controlled to be smaller.

[0051] Figure 3 This is a graph representing the second example of the heating quantity control curve. In the heating cycle apparatus of this embodiment, as... Figure 3 As shown, the following scheme is included: the reduction section 110 is a curve with an inflection point P, where the temperature T at the inflection point P is higher than the target temperature Tt. The temperature T at the inflection point P is preferably above {target temperature Tt} + 0 degrees and below {target temperature Tt} + 4 degrees, more preferably above {target temperature Tt} + 1 degree and below {target temperature Tt} + 2 degrees. When the temperature T at the inflection point P exceeds {target temperature Tt} + 4 degrees, there is a possibility that the coolant is overheated relative to the target temperature. The heating amount control curve 100 (100B) of the second example can reach the target temperature Tt within, for example, 15 minutes and control the temperature relative to the target temperature Tt within, for example, the range of {target temperature Tt} ± 1 degree. Furthermore, the temperature T at the inflection point P is on the higher side compared to the target temperature Tt. Therefore, when the coolant temperature T is the target temperature Tt, it is easy to set the heating capacity E of the heater to be larger. Especially in the vehicle air conditioning unit 900 where the heat dissipation in the radiator 7 is relatively large, it is preferable to control the temperature variation relative to the target temperature Tt to be smaller.

[0052] Figure 4 This is a graph representing the third example of the heating quantity control curve. In the heating cycle apparatus of this embodiment, as... Figure 4As shown, the following scheme is included: the reduction section 110 is a curve with an inflection point P, where the temperature T at the inflection point P is lower than the target temperature Tt, and the second region 111B is located in a region closer to the low temperature side than the inflection point P. The temperature T at the inflection point P is preferably ≥ 4°C (target temperature Tt) and < 0°C (target temperature Tt) and more preferably ≥ 1°C and < 2°C (target temperature Tt) and < 2°C. If the temperature T at the inflection point P is less than 4°C (target temperature Tt) and the time to reach the target temperature Tt becomes longer. In the heating amount control curve 100 (100°C) of the third example, the first reduction section 111 includes a region closer to the high temperature side than the temperature at the inflection point P, namely the third region 111C. The heating control curve 100 (100°C) in the third example can reach the target temperature Tt within, for example, 15 minutes and control the temperature relative to the target temperature Tt within, for example, the range of {target temperature Tt} ± 1°C. Furthermore, the temperature T at the inflection point P is on the lower side compared to the target temperature Tt, so when the coolant temperature T is the target temperature Tt, it is easy to set the heating amount E of the heater to be relatively small. This is particularly true in vehicle air conditioning units 900 where the heat dissipation in the radiator 7 is relatively low, allowing for appropriate control of temperature fluctuations relative to the target temperature Tt.

[0053] Figure 5 This is a graph representing the fourth example of the heating quantity control curve. In the heating cycle apparatus of this embodiment, as... Figure 5 As shown, the scheme includes the following: the first region 111A and the second region 111B are both linear functions with different slopes. The heating control curve 100 (100D) of the fourth example can reach the target temperature Tt within, for example, 15 minutes and control the temperature relative to the target temperature Tt within, for example, the range of {target temperature Tt} ± 1℃.

[0054] Figure 6 This is the fifth example of a graph showing the heating quantity control curve. In the heating cycle apparatus of this embodiment, as... Figure 6 As shown, the following scheme is included: the reduction section 110 is a curve without an inflection point. The heating amount control curve 100 (100E) of the fifth example can reach the target temperature Tt within, for example, 15 minutes and control the temperature relative to the target temperature Tt within, for example, the range of {target temperature Tt} ± 1°C.

[0055] Figure 11 This diagram illustrates an example of duty cycle control in a heating cycle device. (a) shows duty cycle control in the constant temperature section, (b) shows duty cycle control at any temperature in the reducing temperature section, and (c) shows duty cycle control at any temperature in the region corresponding to the heat dissipation. The reducing temperature section 110 ( Figures 2 to 6 The duty cycle of the constant part 120 in the diagram is shown. Figures 2 to 6The duty cycle shown in the diagram is small. In the reduction section 110, the duty cycle is gradually reduced over time, as shown in the diagram. Figures 2 to 6 The heating quantity E of heater 4 is adjusted as shown. Alternatively, in the reduction section 110, the duty cycle is gradually reduced as the temperature of the coolant rises, as shown. Figures 2 to 6 The heating amount E of heater 4 is adjusted as shown.

[0056] The duty cycle is not particularly limited, but is preferably, for example, 0.015 to 0.025 seconds. Figure 11 In (a) to (c), as an example, the duty cycle is set to 0.02 seconds. Constant section 120 ( Figures 2 to 6 The duty cycle shown in the diagram is not particularly limited, but is preferably 60% or more and 100% or less. Figure 11 In (a), as an example, the constant part 120 ( Figures 2 to 6 The duty cycle in the diagram is set to 80%. Reduction section 110 ( Figures 2 to 6 The duty cycle at any temperature (as shown in the diagram) is not particularly limited, but is preferably 30% or more and less than 60%. Figure 11 In (b), as an example, the target temperature Tt ( Figure 2 The duty cycle (as shown in the diagram) is set to 50%. The duty cycle at any temperature in the region corresponding to the heat dissipation is not particularly limited, but is preferably greater than 0% and less than 30%. Figure 11 In (c), as an example, the duty cycle at any temperature in the region corresponding to the heat dissipation is set to 20%.

[0057] exist Figures 2 to 4 In the heating control curve shown, the heating amount at the inflection point P is preferably 70% or less relative to the heating amount in the constant section 120, more preferably 60% or less. When the heating amount at the inflection point P exceeds 70% of the heating amount in the constant section 120, the coolant temperature rises and exceeds the target temperature Tt, but heating continues beyond what is necessary, making it difficult to control the coolant temperature T to approximate the target temperature Tt. The lower limit of the heating amount at the inflection point P is not particularly limited, but it is preferably 30% or more relative to the heating amount in the constant section 120, more preferably 40% or more. If the heating amount at the inflection point P is less than 30% of the heating amount in the constant section 120, the heating amount is insufficient when the coolant temperature approaches the target temperature Tt, resulting in a longer time for the coolant temperature to reach the target temperature Tt.

[0058] The vehicle air conditioning unit 900 of this embodiment is as follows: Figure 1The vehicle air conditioning unit 900, which includes the heating circulation device 1 of this embodiment and is mounted on a vehicle, is shown in the embodiment. The vehicle is capable of motor-driven operation. The vehicle air conditioning unit 900 has a temperature control unit 901 that regulates the temperature of the air supplied to the vehicle interior. The radiator 7 is a hot water heat exchanger disposed inside the temperature control unit 901.

[0059] The vehicle air conditioning unit 900 includes a blower unit 904 and a temperature control unit 901. The blower unit 904 is equipped with a blower 902 that draws in air from an internal gas inlet (not shown) and / or an external gas inlet and delivers it to an airflow path 903. The internal space of the temperature control unit 901 is the airflow path 903, and a hot water heat exchanger (radiator) 7 is arranged in the airflow path 903. Preferably, upstream of the hot water heat exchanger 7 in the airflow path 903, there is also a cooling heat exchanger (not shown) for dehumidifying and cooling the air delivered from the blower unit 904 as needed, and an air mixing damper (not shown) disposed between the cooling heat exchanger and the hot water heat exchanger 7 to adjust the ratio between the air passing through the hot water heat exchanger 7 and the air bypassing the hot water heat exchanger 7. At the downstream end of the temperature control unit 901, there is a defrost opening (not shown), a ventilation opening (not shown), and a foot opening (not shown). Each opening is connected, either indirectly or directly, to an air outlet (not shown) inside the vehicle via a pipe (not shown).

[0060] Vehicles include, for example, electric vehicles (EVs) that run solely on an electric motor, hybrid electric vehicles (HEVs) that run on multiple power sources including an electric motor and an internal combustion engine, or vehicles that run on an electric motor driven by an internal combustion engine that generates electricity. In these vehicles, the total coolant volume in the coolant circuit tends to be less than in vehicles equipped with an engine. When temperature fluctuations occur at the outlet of the fluid heating unit, the effects of these fluctuations can easily spread throughout the entire path. The heating circulation device 1 installed in the vehicle air conditioning system of this embodiment can control temperature fluctuations to a smaller extent. When coolant temperature fluctuations occur, if the vehicle air conditioning system 900 is set to full heating mode and operating, there is a problem that the temperature of the warm air blown out from the vents inside the vehicle interior fluctuates, affecting comfort. Alternatively, if the vehicle air conditioning system 900 is set to temperature adjustment mode and operating, the position of the air mixing damper needs to be frequently adjusted to maintain a constant temperature of the blown warm air, resulting in a problem that the operating noise emitted by the actuator driving the air mixing damper affects comfort.

[0061] Although not shown in the diagram, it is preferable to detect and input the airflow of the blower 902, the temperature of the air upstream of the radiator 7, and the temperature of the blended air downstream of the air mixing damper into the heating control device 6, estimate the heat dissipation in the radiator 7, and adjust the heating control device based on the heat dissipation in the radiator 7. Figures 2 to 4 The inflection point P is the amount of heat generated. Specifically, when the heat dissipation in radiator 7 is relatively high, the inflection point P is adjusted to a value with higher heat generation; when the heat dissipation in radiator 7 is relatively low, the inflection point P is adjusted to a value with lower heat generation. When the heat dissipation in radiator 7 is high, the coolant temperature T can reach the target temperature Tt earlier. When the heat dissipation in radiator 7 is low, the coolant temperature T can be reliably prevented from rising further after reaching the target temperature Tt, thus enabling control of the coolant temperature T to approximate the target temperature Tt. Example

[0062] The present invention will now be described in more detail based on embodiments, but the present invention is not limited to the embodiments described herein.

[0063] (Example 1) Heating control device based on Figure 2 The heating control curve shown controls the switching action of the transistor, changing the on-off duty cycle of the transistor to adjust the heating amount of the heater. The target temperature is set to 80℃. Figure 12 This is a graph showing the relationship between heating time and coolant temperature in Example 1. Figure 12 In the diagram, the area marked with reference numeral 301 corresponds to... Figure 2 The constant part 120, the area marked with 302 corresponds to the first reducing part 111, and the area marked with 303 corresponds to the second reducing part 112.

[0064] (Comparative Example 1) In addition to changing the heating control curve Figure 7 In addition to the curve shown, the heating amount of the heater is adjusted in the same manner as in Example 1. The target temperature is set to 80°C. Figure 13 This is a graph showing the relationship between heating time and coolant temperature in Comparative Example 1.

[0065] (Comparative Example 2) In addition to changing the heating curve to Figure 9 In addition to the curve shown, the heating amount of the heater is adjusted in the same manner as in Example 1. The target temperature is set to 80°C. Figure 14 This is a graph showing the relationship between heating time and coolant temperature in Comparative Example 2.

[0066] like Figure 12As shown, in Example 1, the time to reach the target temperature is within 15 minutes, demonstrating that the target temperature can be reached in a short time. Furthermore, the temperature fluctuation relative to the target temperature is within ±1°C, indicating that temperature fluctuations can be kept relatively small. In contrast, as... Figure 13 As shown, Comparative Example 1 reached the target temperature within 15 minutes, but the temperature variation relative to the target temperature was ±5°C, indicating a significant temperature fluctuation. Figure 14 As shown, for Comparative Example 2, the temperature variation relative to the target temperature was within ±1°C of the target temperature, but the time to reach the target temperature exceeded 20 minutes, which is a relatively long time. Explanation of reference numerals in the attached figures

[0067] 1. Heating circulation device; 2. Circulating flow path; 3 pumps; 4. Heater; 5 transistors; 6. Heating control device; 7. Radiator; 8 batteries; 10. Fluid heating unit; 10a Outlet; 10b Inlet; 11, 12, 13 piping; 50 Temperature sensor; 100 (100A~100E) Heating quantity control curve; 110. Reduction of department; 111 First reduction section; 112 Second reduction section; 111A, Area 1; 111B Second Zone; 111C Third Region; 112A heat dissipation corresponding area; Curves 200, 201, 202, and 203; 900 Air conditioning unit for vehicles; 901 Temperature Control Unit; 902 Blower; 903 Airflow path; 904 Blower Unit; P inflection point.

Claims

1. A heating control device (6) that controls a transistor (5) that supplies power to a heater (4) via a switching action, the heater (4) generating heat by being energized and heating coolant supplied to a radiator (7) mounted on a vehicle air conditioning unit, characterized in that, The heating control device (6) controls the switching action of the transistor (5) based on the heating amount control curve (100 (100A~100E)), thereby changing the on-off duty cycle of the transistor (5) to adjust the heating amount of the heater (4). The heating amount control curve (100 (100A~100E)) is a function representing the relationship between the temperature T of the coolant and the heating amount E of the heater (4), and has a reduction portion (110) in which the heating amount E decreases as the temperature T rises from the low temperature side to the high temperature side across the target temperature Tt of the coolant. The reducing section (110) has a first reducing section (111) when the temperature T is in the temperature range below the target temperature Tt and a second reducing section (112) when the temperature T is in the temperature range above the target temperature Tt, and the first reducing section (111) and the second reducing section (112) have equal heating amounts E at the target temperature Tt. Both the first reduction part (111) and the second reduction part (112) have negative slopes in the function. The first reduction section (111) has a first region (111A) and a second region (111B) that is located on the high-temperature side of the first region (111A). The slope of the heating amount control curve (100 (100A~100E)) at any temperature in the second region (111B) is more negative than the slope of the heating amount control curve (100 (100A~100E)) at any temperature in the first region (111A).

2. The heating control device according to claim 1, characterized in that, The reduction portion (110) is a curve with an inflection point P. The temperature T at the inflection point P is the same as the target temperature Tt.

3. The heating control device according to claim 1, characterized in that, The reduction portion (110) is a curve with an inflection point P. The temperature T at the inflection point P is higher than the target temperature Tt.

4. The heating control device according to claim 1, characterized in that, The reduction portion (110) is a curve with an inflection point P. The temperature T at the inflection point P is lower than the target temperature Tt. The second region (111B) is located on the lower temperature side than the inflection point P.

5. The heating control device according to claim 1, characterized in that, The first region (111A) and the second region (111B) are both linear functions with different slopes in the function.

6. The heating control device according to claim 1, characterized in that, The reduction section (110) is a curve without an inflection point P.

7. The heating control device according to any one of claims 1 to 6, characterized in that, The heating amount control curve (100 (100A~100E)) has a constant part (120) at a low temperature side compared to the first reduction part (111), where the heating amount (E) remains constant even though the temperature T rises from the low temperature side to the high temperature side.

8. The heating control device according to any one of claims 1 to 6, characterized in that, The second reduction section (112) has a heat dissipation area (112A) at a temperature higher than the target temperature Tt, which maintains the heating amount E at a predetermined heating amount.

9. A fluid heating unit (10), characterized in that, It comprises a heater (4) that generates heat by being energized and heats the coolant, a transistor (5) that supplies power to the heater (4) by a switching action, and a heating control device (6) according to any one of claims 1 to 8. The heating control device (6) controls the switching action of the transistor (5).

10. A heating circulation device, characterized in that, It includes a circulation path (2), a coolant filled in the circulation path (2), a pump (3) for circulating the coolant in the circulation path (2), a fluid heating unit (10) according to claim 9 for adjusting the temperature of the coolant, and a radiator (7) for dissipating heat from the coolant. The coolant is heated in the fluid heating unit (10) by energizing the heater (4) using the transistor (5).

11. A vehicle air conditioning unit (900), mounted on a vehicle, comprising the heating circulation device (1) as described in claim 10, characterized in that, The vehicle is capable of motor-driven propulsion. The vehicle air conditioning unit (900) has a temperature control unit (901) for regulating the temperature of the air supplied to the vehicle interior. The radiator (7) is a hot water heat exchanger disposed inside the temperature control unit (901).

12. A control program product, characterized in that, The control program product is configured to cause the heating control device (6) according to any one of claims 1 to 8 to perform the switching action processing of the transistor (5) based on the heating amount control curve (100 (100A~100E)).

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