JP2014172478A - Refrigeration cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration cycle device configured to further suppress overshoot and hunting.SOLUTION: The refrigeration cycle device performs: a step S34 of arithmetically calculating a target evaporator temperature TEO of an evaporator 45; a step S35 of arithmetically calculating an initial control value Iouts in controlling of a compressor 41; a step S48 of arithmetically calculating a capacity control value Iout(n) of the compressor on the basis of a temperature deviation E(n) between the target evaporator temperature TEO and an actual evaporator temperature TE; steps S41 and S41a of determining that an operating temperature of the evaporator becomes a predetermined temperature after the compressor 41 is controlled based on the initial control value Iouts; and steps S45 to S49 of keeping controlling of the compressor 41 on the basis of the initial control value Iouts until determining the operating temperature becomes the predetermined temperature and starting control by the capacity control value Iout(n) after sensing response of the predetermined evaporator temperature.

Description

  The present invention relates to temperature control in a refrigeration cycle apparatus. In particular, it relates to temperature control in a vehicle air conditioner that forms a refrigeration cycle apparatus.

  By sensing the evaporator temperature as a control target and controlling the discharge capacity of the variable capacity compressor and the rotational speed of the electric compressor from the outside so that the temperature matches the target temperature, the compressor capacity control value can be set. Temperature control of air conditioners that transmit and control the compression function is well known. The evaporator temperature control in this known technology is started simultaneously with the compressor ON (compressor start) of the refrigeration apparatus.

  Further, the compression function force control is generally performed using feedback control such as PI control or PID control. The control characteristics (control initial value, control gain, etc.) of this feedback control are examined on the assumption that the evaporator temperature responds immediately after the refrigeration cycle is activated and the compressor is turned on. As a result, complicated adjustment work is performed so that the overshoot and undershoot of the evaporator temperature are small and appropriately controlled.

  However, depending on the situation before the operation of the refrigeration system, the evaporator temperature response may be delayed even when the compressor is turned on. For example, when the operation is started after the refrigeration apparatus is not operated for a long time, the refrigerant is biased and stays in the refrigeration cycle. Therefore, after the compressor is turned on, it takes time for the refrigerant to circulate in the refrigeration cycle and flow into the evaporator, resulting in a situation where the response of the evaporator temperature to the compressor ON is delayed. Also, this time is not constant.

  However, the feedback control of the air conditioner is started at the same time as the compressor is turned on regardless of whether the evaporator temperature responds immediately or delayed, so that the compression function force is the capacity during the evaporator temperature response delay. It is controlled to increase. Therefore, the capacity becomes excessive, and as a result, problems such as the occurrence of frost due to a large overshoot of the evaporator temperature and the deterioration of the air conditioning feeling due to the large fluctuation of the blowing temperature occur.

  The above-mentioned problem occurs because the feedback control of the air conditioner is started simultaneously with the compressor ON regardless of whether the evaporator temperature responds immediately after the compressor is turned on or is delayed. Accordingly, for example, Patent Document 1 discloses that the compressor is turned on at a certain compression function force initial value and temperature control is started and the compression function force initial value is held for a while.

  In this refrigeration cycle apparatus equipped with a variable capacity compressor, capacity control with less temperature fluctuation until reaching the target temperature is achieved in spring, autumn, and other seasons that do not require cooling capacity as in midsummer. Is what you do. Therefore, the vehicle air conditioner has a variable capacity with a control current corresponding to the target blown air temperature TEO as an initial output value when the target blown air temperature TEO of the evaporator is around 10 ° C. in seasons such as spring and autumn. Control the capacity of the mold compressor.

  Thereby, the apparatus of patent document 1 starts control from the initial output value corresponding to the target blowing air temperature TEO of an evaporator. By doing so, as compared with the conventional case where the capacity control is performed using the control current with the discharge capacity as 100% as the initial output value, the actual blown air temperature TE reaches the target blown air temperature TEO of the evaporator. Overshoot and temperature fluctuation (hunting) are reduced.

  Specifically, in the spring and autumn seasons when the heat load is not as high as in midsummer, the suction pressure of the compressor is substantially determined by the control current. A predetermined proportional relationship is established between the target blown air temperature TEO of the evaporator and the initial output value.

  And the target blowing air temperature TEO of an evaporator is calculated | required based on the target blowing temperature TAO. Subsequently, a temperature deviation En between the target blown air temperature TEO of the evaporator and the actual blown air temperature TE is calculated. Thereafter, it is determined whether or not the number of samplings n is “1”. If n = 1 (YES), both the 0th time and the first time of the temperature deviation En are set to “0”.

  Next, an initial output value corresponding to the target blown air temperature TEO of the evaporator is obtained. When the number of times of sampling n = 1, the initial output value becomes the output value of the control current In. When the number of samplings n is the second or later, the control current In calculated using the temperature deviation En between the target blown air temperature TEO of the evaporator and the actual blown air temperature TE is output.

JP-A-6-255354

  According to the technique of Patent Document 1, when n = 1, the compressor is controlled with the initial output value, and the normal control current In calculated using the temperature deviation En is output after the second sampling time n. The That is, the time from when the compressor is controlled with the initial output value to when the regular control current In is output is constant. Although this is an improvement over the conventional apparatus, complicated adjustment work is required, and if adjustment is not successful, overshoot and hunting remain.

  The present invention has been made paying attention to such problems existing in the prior art, and an object thereof is to provide a refrigeration cycle apparatus in which overshoot and hunting are further suppressed.

  Descriptions of patent documents listed as prior art can be introduced or incorporated by reference as explanations of technical elements described in this specification.

  In order to achieve the above object, the present invention employs the following technical means. That is, in this invention, it has the following structures in the refrigerating-cycle apparatus which evaporates the refrigerant | coolant compressed with the compressor (41) in an evaporator (45). The refrigeration cycle apparatus calculates the actual evaporator temperature detecting means (45c) for detecting the actual evaporator temperature (TE) by the operation of the evaporator (45), and the target evaporator temperature (TEO) of the evaporator (45). And target evaporator temperature calculation means (S34). The refrigeration cycle apparatus has control initial value calculation means (S35) for calculating a control initial value (Iouts) in the control of the compressor (41). The refrigeration cycle apparatus calculates the capacity control value (Iout (n)) of the compressor from the temperature deviation (E (n)) between the target evaporator temperature (TEO) and the actual evaporator temperature (TE). Means (S45 to S48). The refrigeration cycle apparatus includes determination means (S41, S41a) for determining that the evaporator (45) has reached a predetermined temperature state after controlling the compressor (41) with the control initial value (Iouts). The refrigeration cycle apparatus retains control of the compressor (41) based on the initial control value (Iouts) until it is determined that the determination means (S41, S41a) has reached a predetermined temperature state (S49). Have This compressor control means (S49) is characterized by starting control of the compressor (41) by the capacity control value (Iout (n)) of the compressor after reaching a predetermined temperature state.

  According to this invention, after controlling the compressor (41) with the control initial value (Iouts), the determination means (S41, S41a) for determining that the evaporator (45) is in a predetermined temperature state is provided. The control of the compressor (41) based on the initial control value (Iouts) is maintained until the determination means (S41, S41a) determines that the evaporator (45) has reached a predetermined temperature state due to refrigerant compression. To do. Then, after reaching a predetermined temperature state, control of the compressor (41) by the compressor capacity control value (Iout (n)) is started. Therefore, it is possible to provide a refrigeration cycle apparatus that can more reliably suppress control delay, overshoot, and hunting even when the time until the evaporator (45) reaches a predetermined temperature state due to refrigerant compression changes depending on the situation. .

  In addition, the code | symbol in parentheses described in a claim and each said means is an example which shows the correspondence with the specific means as described in embodiment mentioned later easily, and limits the content of invention is not.

It is a schematic diagram explaining the arrangement | positioning state of the air conditioning unit of the vehicle air conditioner in 1st Embodiment of this invention. It is a schematic diagram of the vehicle air conditioner in the said embodiment. It is a flowchart which shows the whole control of the vehicle air conditioner in the said embodiment. It is a flowchart which shows the front | former part of the evaporator temperature control using the variable capacity compressor in the said embodiment. It is a flowchart which shows the back | latter stage part of the evaporator temperature control using the variable capacity compressor in the said embodiment. It is a characteristic view which shows the operation | movement of the said embodiment compared with a comparative example. It is a partial flowchart of evaporator temperature control using the variable capacity compressor in 2nd Embodiment of this invention. 10 is a partial flowchart showing a pre-stage part of evaporator temperature control in a third embodiment of the present invention. It is a partial flowchart which shows the front | former part of evaporator temperature control in 4th Embodiment of this invention.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration.

  Not only combinations of parts that clearly indicate that the combination is possible in each embodiment, but also the embodiments are partially combined even if they are not clearly specified unless there is a problem with the combination. It is also possible.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. In FIG. 1, the air conditioning unit 2 is disposed inside an instrument panel 4 in front of the passenger compartment. Etc. are provided. The vehicle air conditioner is roughly divided into an air conditioning unit 2, a blower 30 in FIG. 2, a refrigeration cycle 40, a cooling water circuit 50, an air conditioner ECU (air conditioning control means in the present invention) 60, and the like.

  The air conditioning unit 2 includes an air conditioning case 10 that is disposed in front of the vehicle interior and forms an air passage that guides conditioned air into the vehicle interior, and a centrifugal blower 30 that generates an air flow in the air conditioning case 10. The air conditioning unit 2 includes an evaporator 45 for cooling the air flowing in the air conditioning case 10 to cool the vehicle interior, a heater core 51 for heating the air flowing in the air conditioning case 10 to heat the vehicle interior, and the like. It is composed of

  The most upstream side of the air flow case 10 of the air conditioning case 10 is a portion constituting an inside / outside air switching box (suction port switching box), and an inside air suction port 11 for taking in vehicle interior air (inside air) and outside air for taking in air outside the vehicle compartment (outside air). A suction port 12 is provided. Furthermore, an inside / outside air (suction port) switching door 13 is rotatably attached to the inside of the inside air suction port 11 and the outside air suction port 12.

  The inside / outside air switching door 13 is driven by an actuator (not shown) such as a servo motor, and is switched to an inside air circulation mode or an outside air introduction mode as a suction mode. The inside / outside air switching door 13 constitutes inside / outside air switching means together with the inside / outside air switching box. Next, the blower 30 includes a centrifugal multi-blade (sirocco) blower fan 31 rotatably accommodated in a scroll case integrally formed with the air conditioning case 10, and a blower motor that rotationally drives the blower fan 31. 32.

  The blower motor 32 uses a three-phase brushless motor capable of current control, and has a motor drive circuit (not shown) that variably controls the pulse width applied to the blower motor 32 in accordance with a duty signal from the air conditioner ECU 60. . The blower motor 32 controls the rotational speed of the blower fan 31, that is, the air flow rate, based on the control current supplied via the motor drive circuit. Instead of the brushless motor, a direct current motor with a normal control circuit can be used.

  The refrigeration cycle 40 includes a compressor 41 that is belt-driven by the vehicle running engine 1 to compress the refrigerant, a condenser 42 that condenses and liquefies the compressed refrigerant, and a liquid refrigerant that gas-liquid separates the condensed and liquefied refrigerant. And a liquid receiver 43 that flows only downstream. The refrigeration cycle 40 includes an expansion valve 44 that decompresses and expands the liquid refrigerant, an evaporator 45 that evaporates and vaporizes the decompressed and expanded refrigerant, and a refrigerant pipe that connects these in an annular shape.

  The compressor 41 is a variable capacity compressor whose compression capacity can be varied by a built-in capacity variable mechanism, and the compression capacity is controlled by a capacity control valve (capacity control mechanism) (not shown) as a cooling capacity variable means. This capacity control valve is controlled by the air conditioner ECU 60. The compressor 41 is connected to an electromagnetic clutch 46 as a clutch means for intermittently (ON, OFF) transmission of rotational power from the engine 1 to the compressor 41.

  The electromagnetic clutch 46 is controlled from the air conditioner ECU 60 via a clutch drive circuit (not shown). When the electromagnetic clutch 46 is energized, the rotational power of the engine 1 is transmitted to the compressor 41 and the air cooling action by the evaporator 45 is performed. Further, when the energization of the electromagnetic clutch 46 is stopped, the connection between the engine 1 and the compressor 41 is cut off, and the air cooling action by the evaporator 45 is stopped.

  The condenser 42 is disposed in the front part of the vehicle, which is susceptible to traveling wind generated when the vehicle travels, and performs outdoor heat exchange for exchanging heat between the refrigerant flowing inside and the traveling air and the outside air blown by the cooling fan 47. It is a vessel. The evaporator 45 is disposed in the air conditioning case 10 so as to block the entire air passage, and performs indoor cooling that cools the air that passes through the evaporator 45 and performs air dehumidifying that dehumidifies the air that passes through the evaporator 45. It is an exchanger.

  In other words, the evaporator 45 is a cooling heat exchanger that cools and dehumidifies the conditioned air by the operation of the compressor 41. An actual evaporator temperature sensor 45c composed of a thermistor (not shown) is disposed immediately after the evaporator 45, and the air temperature or fin temperature immediately after passing through the evaporator 45 (hereinafter referred to as the post-evaporator temperature or actual temperature). It is designed to detect the evaporator temperature).

  The cooling water circuit 50 is a circuit that circulates the cooling water heated by the water jacket of the engine 1 by a water pump (not shown), and includes a radiator, a thermostat (all not shown), and a heater core 51. In the heater core 51, cooling water for cooling the engine 1 flows inside, and the cooling air is heated by using the cooling water as a heat source for heating.

  The heater core 51 is disposed in the air conditioning case 10 so as to partially block the air passage on the downstream side of the evaporator 45. That is, a cold air bypass passage (cold air passage) 14 </ b> A that bypasses the heater core 51 and a hot air passage 14 </ b> B that passes through the heater core 51 are formed inside the air conditioning case 10. An air mix door 52 is rotatably attached to the air upstream side of the heater core 51.

  The air mix door 52 is driven by an actuator (not shown) such as a servo motor, and adjusts the ratio of the amount of air passing through the heater core 51 and the amount of air bypassing the heater core 51 depending on the stop position. The air mix door 52 functions as a blowing temperature adjusting means for adjusting the blowing temperature of the air blown into the vehicle interior. A mixing space 14C is formed on the downstream side of the cold air bypass passage 14A and the hot air side passage 14B in the air conditioning case 10, and the cold air from the cold air bypass passage 14A and the hot air from the hot air side passage 14B are mixed to form the following. It is supplied to each opening.

  The most downstream side of the air flow of the air-conditioning case 10 is a portion constituting the outlet switching box, and a defroster opening 18, a face opening 19, a foot opening 20, and the like are formed. A defroster duct 15 is connected to the defroster opening 18, and a defroster outlet 5 (FIG. 1) that mainly blows warm air toward the inner surface of the front window glass 3 of the vehicle at the most downstream end of the defroster duct 15. Is open.

  Further, a face duct 16 is connected to the face opening 19, and a face air outlet 6 that blows mainly cool air toward the head and chest of the front seat occupant is opened at the most downstream end of the face duct 16. . Further, a foot duct 17 is connected to the foot opening 20, and a foot outlet 7 that mainly blows warm air toward the feet of the front seat occupant opens at the most downstream end of the foot duct 17. Yes.

  And in the inside of each blower outlet 5-7, in this embodiment, two blower outlet switching doors, specifically, the defroster face door 21 and the foot door 22 are attached rotatably as blower outlet switching means. It has been. The defroster face door 21 varies the opening ratio between the defroster opening 18 and the face opening 19, and the foot door 22 is a door that varies the opening of the foot opening 20.

  The two outlet switching doors 21 and 22 are interlocked by a link mechanism (not shown), and the link mechanism is driven by an actuator (not shown) such as a servo motor. Then, the blowing mode can be switched to any one of the face mode, the bi-level mode, the foot mode, the foot defroster mode, and the defroster mode.

  In the face mode, the entire amount of conditioned air is blown out from the face air outlet 6, and in the bi-level mode, conditioned air is blown out from the face air outlet 6 and the foot air outlet 7. In the foot mode, about 80% of the total blown air volume is blown out from the foot outlet 7, and the remaining about 20% of the conditioned air is blown out from the defroster outlet 5.

  In the foot defroster mode, about 60% of the total blown air volume is blown from the foot blower outlet 7, and the remaining 40% of the conditioned air is blown from the defroster blower outlet 5. Further, in the defroster mode, the entire amount of conditioned air is blown out from the defroster outlet 5.

  The air conditioner ECU 60 is supplied with DC power from a battery (not shown) that is an in-vehicle power source mounted on the vehicle so as to perform arithmetic processing and control processing regardless of ON / OFF of the ignition switch that controls starting and stopping of the engine 1. It is configured. The air conditioner ECU 60 is configured such that each switch signal is input from various operation switches on an air conditioner operation panel (not shown) that are integrally installed on the instrument panel 4.

  The air conditioner ECU 60 includes functions such as a CPU (central processing unit) that performs arithmetic processing and control processing, memories such as ROM and RAM, and an I / O port (input / output circuit). A well-known microcomputer is provided. The sensor signals from various sensors are A / D converted by an I / O port or an A / D conversion circuit, and then input to a microcomputer.

  In other words, the air conditioner ECU 60 includes an inside air temperature sensor as an inside air temperature detecting unit that detects the vehicle interior temperature (inside air temperature) and an outside air temperature sensor as an outside air temperature detecting unit that detects the outside temperature (outside air temperature) of the vehicle interior. In addition, the air conditioner ECU 60 includes an actual post-evaporator temperature sensor that constitutes an actual evaporator temperature detection unit as post-evaporator temperature detection unit that detects air or fin temperature (post-evaporator temperature) immediately after passing through the evaporator 45. Prepare. And detection signals, such as a cooling water temperature sensor as a heating temperature detection means which detects the engine cooling water temperature of a vehicle and makes it the heating temperature of blowing air, are input into air-conditioner ECU60.

  In the present embodiment, a solar radiation sensor is provided as the solar radiation detection means provided in the automatic air conditioner. The air conditioner ECU 60 outputs control signals to the door actuators described above, the motor drive circuit of the blower motor 32, the capacity control valve of the compressor 41, the clutch drive circuit of the electromagnetic clutch 46, the drive circuit of the cooling fan 47, and the like. It is supposed to be.

  Hereinafter, a control method by the air conditioner ECU 60 will be described. FIG. 3 shows an example of a control program of the air conditioner ECU 60. First, when the ignition switch is turned on and DC power is supplied to the air conditioner ECU 60, execution of the control program stored in advance in the memory is started. First, the contents stored in the data processing memory built in the microcomputer inside the air conditioner ECU 60 are initialized (step S1).

  Next, various data is read into the data processing memory as input processing of various signals. That is, switch signals from various operation switches on the air conditioner operation panel, sensor signals from various sensors, the magnitude of the output voltage Vsun of the solar radiation sensor 9 (FIG. 2), and the like are input (step S2).

  Next, the above input data is substituted into the stored arithmetic expression to calculate the target blowing temperature TAO from the air conditioner, and the target post-evaporator temperature TEO is calculated from the target blowing temperature TAO and the outside air temperature. Calculation is performed (step S3). Then, the blower control amount, that is, the duty ratio given to the motor drive circuit of the blower motor 32 is calculated based on the target blowing temperature TAO obtained in step S3 (step S4).

  Further, the opening degree SW (%) of the air mix door 52 is calculated by substituting the target blowing temperature TAO obtained in step S3 and the above input data into an arithmetic expression stored in the memory (step S5). . Next, based on the target blowing temperature TAO obtained in step S3, an air flow suction mode to be taken into the vehicle interior and an air flow blow mode to be blown into the vehicle compartment are determined (step S6).

  Further, feedback control is executed so that the target outlet temperature TAO obtained in step S3 matches the actual evaporator downstream temperature detected by the actual evaporator temperature sensor 45c. This control is performed by evaporator temperature control (step S7) for determining a control amount (current value) for controlling the discharge amount of the compressor 41.

  This feedback control is performed by proportional-integral control (PI control). Specifically, a solenoid current (control current: Ioutn) that is a control current supplied to an electromagnetic solenoid of an electromagnetic capacity control valve attached to the compressor 41 is calculated based on an arithmetic expression stored in a memory. To do. The evaporator temperature control (step S7) will be described later in detail.

  Next, the blower control amount determined in step S4 is output to the motor drive circuit (step S8). Next, a control signal is output to the servomotor so that the air mix opening SW determined in step S5 is obtained (step S9). Further, a control signal is output to the servo motor so that the suction mode and the blowing mode determined in step S6 are obtained (step S10).

  Thereafter, the process returns to the control process of step S2. At the time of manual setting, the control program of FIG. 2 is executed according to the set value.

  Hereinafter, the above-described evaporator temperature control (step S7) will be further described. Details of the evaporator temperature control using the variable capacity compressor 41 that varies the refrigerant discharge amount in accordance with an external control signal are shown in the flowcharts of FIGS. 4 and 5. When the evaporator temperature control is started in step S30 in FIG. 4, the number of samplings (sampling count value) n = 1 is set in step S31 as an initial value in the case of performing feedback control. In step S32, temperature deviations Es (n-1) = 0 and E (n-1) = 0 are set. Note that n is a positive integer.

  Next, in step S33, various information such as the cabin temperature, the outside air temperature, and the amount of solar radiation representing the operating state of the air conditioner is input (read). In step S34, the target blowing temperature (TAO) is calculated from various information representing the operating state of the air conditioner as is well known, and further, the target evaporator temperature TEO is calculated from the target blowing temperature (TAO) and the outside air temperature. The target evaporator temperature TEO may be calculated using a map from the target outlet temperature (TAO) or the like.

  An appropriate control initial value Iouts corresponding to the cycle is calculated in step S35 constituting the control initial value calculating means. In step S36, the actual evaporator temperature TEs at the start of the evaporator temperature control is read from the actual evaporator temperature sensor 45c, and the read value is stored in the memory. Further, in S37, the control initial value Iouts calculated in the previous step S35 is output to the compressor, and the compressor 41 is operated. Specifically, the control initial value Iouts, which is a solenoid current, is output to the electromagnetic solenoid of the electromagnetic capacity control valve attached to the compressor 41.

  Note that the control initial value Iouts is obtained from a target blowout temperature TAO by a map, for example. This map is set in advance by experiments. In addition, the map may be obtained from the vehicle interior temperature, the amount of solar radiation, the outside air temperature, and the like.

  From here, it becomes a routine for determining whether or not there is a response to the actual evaporator temperature TE (n) after the compressor 41 is turned on. In step S38, the current actual evaporator temperature TE (n) after the compressor is operated is read from the output of the actual evaporator temperature sensor 45c. In this first embodiment, the actual evaporator temperature sensor 45c is composed of a thermistor (not shown) disposed at a position immediately after the evaporator 45. In step S39, the temperature deviation Es (n) between the actual evaporator temperature TEs before the compressor operation (or immediately after the operation) and the actual evaporator temperature TE (n) after the compressor operation is set to Es (n) = TE. (N) Calculate as -TEs.

  Next, in step S40, the rate of change Esdot (n) of the temperature deviation Es (n) is calculated. The change rate Esdot (n) of the temperature deviation Es (n) is obtained by subtracting the previous temperature deviation Es (n−1) from the current temperature deviation Es (n) as the temperature deviation change rate Esdot (n). Yes.

Further, after the compressor 41 is turned on, the process proceeds to step S41 for determining whether the actual evaporator temperature TE (n) has a response and the temperature has changed. In this step S41, (condition 1) the temperature deviation Es (n) is smaller than the first predetermined threshold value X or in other words, the current actual evaporator temperature TE (n) is the actual evaporator before the compressor is operated. Whether or not the temperature TEs has fallen more than a value related to the threshold value X,
(Condition 2) Whether the rate of change Esdon (n) of the temperature deviation is equal to or less than a value related to the threshold value Y that is the second predetermined value,
Calculate Here, the threshold values X and Y may be set to appropriate values according to the refrigeration cycle. Note that both the X and Y values are negative values in the first embodiment. A negative temperature deviation change rate Edon (n) indicates that the slope of the temperature change is decreasing.

  If both condition 1 and condition 2 are satisfied, it is determined that the actual evaporator temperature TE (n) has a response and the actual evaporator temperature TE (n) has substantially changed. That is, it is determined that the compressor 41 is rotated, the refrigerant sufficiently flows into the evaporator 45, and the evaporator 45 is sufficiently cooled. And after this determination, it progresses after the normal evaporator temperature control routine shown by step S45 of FIG.

  If either condition 1 or condition 2 does not hold, the compressor 41 is operating, but it is determined that there is no response to the actual evaporator temperature TEs before or immediately after the compressor 41 starts operating. The process returns to step S37 via steps S42 and S43. In step S42, the value of E (n) is substituted into E (n-1) (this is expressed as E (n-1) ← E (n)). In step S43, a value of n + 1 is substituted for n (n ← n + 1).

  Thus, until it is determined that there is a response to the actual evaporator temperature TEs (until YES in step S41), the capacity control value of the compressor 41 is maintained at the initial value Iouts. As a result, the capacity control value of the compressor 41 does not become excessive due to the evaporator temperature control. In this case, in preparation for the next determination, the value of E (n) is substituted for E (n-1) in S42, the value of n + 1 is substituted for n in S43, and the process returns to step S37.

  Therefore, the determination of the presence or absence of the actual evaporator temperature response after the compressor 41 is turned on (step S41) is continued. The time until it is determined that there is a response to the actual evaporator temperature TEs is not constant, and varies depending on the vehicle type, the outside air temperature, the operation history of the compressor 41, and the like. It is not uncommon for this time to take 1 minute to 30 seconds.

  As described above, even if a situation occurs in which the response of the actual evaporator temperature after the compressor 41 is turned on is delayed by the control flow up to step S43, the evaporator temperature control in which the compression functional force becomes excessive is not performed. For this reason, problems such as generation of frost due to large overshoot of the actual evaporator temperature and deterioration of air conditioning feeling due to large temperature fluctuation can be prevented.

  Steps S45 and after in FIG. 5 show examples of actual evaporator temperature control by general PI control. As the control after step S45, a known control for the compressor 41 can be adopted.

  In step S41 of FIG. 4, the actual evaporator temperature TE (n) has a response, and after determining that the temperature has sufficiently decreased (YES in step S41), the actual evaporator temperature TE ( n) is read.

  Next, in step S46, the temperature deviation E (n) between the target evaporator temperature TEO and the actual evaporator temperature TE (n) is calculated as E (n) = TE (n) −TEO. In step S47, the rate of change Edot (n) of the temperature deviation E (n) is calculated as Edot (n) = E (n) −E (n−1).

In step S48, the temperature deviation E (n) and the temperature deviation change rate Edot (n) are used to determine the capacity control value Iout (n) of the compressor 41 using Equation 1 based on the feedback theory.
(Expression 1) Iout (n) = Iout (n-1) + Kp * Edot (n) + Ki * E (n)
Kp and Ki are feedback gains. Note that * represents multiplication.

  Steps S45 to S48 constitute capacity control value calculation means. Next, the capability control value Iout (n) is output to the compressor 41 in step S49. Specifically, a control initial value Iout (n) that is a solenoid current is output to an electromagnetic solenoid of an electromagnetic capacity control valve attached to the compressor 41.

  In step S48, the compressor capacity control value Iout (n) is determined by PI feedback control using a proportional term and an integral term. However, the capability control value Iout (n) may be determined using PID feedback control or feedforward control in which a differential term is added to a proportional term and an integral term.

  In step S50, it is determined whether or not to continue the evaporator temperature control. It is determined that the evaporator temperature control is not continued when the air conditioner switch is turned off, the engine 1 is stopped, or an abnormal stop signal is generated.

  If it is determined that the air conditioner switch is not turned OFF and the control is continued in step S50, the process proceeds to step S52, and the value of Iout (n) is substituted into Iout (n-1) in preparation for the next feedback control. Further, in step S53, the value of E (n) is substituted for E (n-1), and in step S54, the value of n + 1 is substituted for n. Then, the process returns to step S45, and the evaporator temperature control is continued. If it is determined in step S50 that the control is not continued, the process branches to step S51, and the evaporator temperature control is terminated.

  In this embodiment, step S41 (FIG. 4) for determining whether or not there is a response to the actual evaporator temperature TE (n) is determined from the conditions 1 and 2. Condition 1 is that the temperature deviation Es (n) between the current actual evaporator temperature TE (n) and the actual evaporator temperature TEs at the start of the evaporator temperature control is smaller than a predetermined threshold value X. In other words, this is based on the condition that the actual evaporator temperature TE (n) at the present time is lower than the actual evaporator temperature TEs before the operation of the compressor 41 by a threshold value X or more. Secondly, the condition is that the change rate Esdot (n) of the temperature deviation is equal to or less than the threshold value Y. However, the determination in step S41 may be performed using only condition 1 or condition 2, as in the second embodiment described later.

  Moreover, in the said embodiment, although demonstrated using the compressor which controls capacity | capacitance by controlling discharge capacity from the outside, the electric motor which can control a compression functional force by controlling compressor rotation speed from the outside. The system may be configured using a compressor.

(Operation of the first embodiment)
Hereinafter, the operation of the first embodiment will be described in comparison with a comparative example with reference to FIG. FIG. 6A shows a state where the actual evaporator temperature converges to the target evaporator temperature as time passes. T <b> 1 is a capacity control start time of a compressor as a general comparative example. T2 is an example of the start point of the capacity control of the compressor according to the first embodiment. A rough broken line C1 indicates a case where the evaporator temperature response is fast in general feedback control (when this control is unnecessary). A fine broken line C2 has a period P1 in which the evaporator temperature response is delayed by general feedback control, and indicates a state in which an overshoot P2 occurs. A solid line C3 is feedback control based on the first embodiment. When the compressor 41 is turned off and turned on immediately, there is no delay in the refrigerant flow, and good control is performed as indicated by the broken line C1 without performing this control.

  FIG. 6B shows that the compressor 41 driven by the power of the engine 1 (FIG. 1) via the electromagnetic clutch 46 is switched from the OFF state to the ON state of the electromagnetic clutch 46, and the compressor capacity control value is shown. Shows a state that fluctuates as time elapses from the control initial value Iouts.

  Sp indicates a characteristic portion according to the first embodiment in which the control initial value Iouts is held during the response delay of the evaporator temperature. At time T1, the clutch 46 of the compressor 41 is turned on, and the compressor 41 starts to rotate.

  The rough broken line C1 in FIG. 6B shows a case where the evaporator temperature response is fast in general feedback control. At this time, the compressor capacity control value is ideal in which the period during which the compression function force is excessive is small. State. The fine broken line C2 has a period P1 in which the evaporator temperature response is delayed by general feedback control.

  Therefore, the compression function force is greatly excessive in the portion P3 corresponding to the delay in the evaporator temperature response. The overshoot P2 is caused by the excessive compression function force. A solid line C3 is feedback control based on the first embodiment. Since the compressor 41 is configured to maintain the control initial value Iouts of the compression function force for a predetermined period Sp after the rotation of the compressor 41 starts (that is, during the evaporator temperature response delay), an overshoot has occurred. Absent. Therefore, fluctuation (hunting) of the blowing temperature due to overshoot does not occur.

(Operational effects of the first embodiment)
In the refrigeration cycle apparatus in the first embodiment, the actual evaporator temperature for detecting the actual evaporator temperature TE due to the operation of the evaporator 45 in the refrigeration cycle apparatus that evaporates the refrigerant compressed by the compressor 41 in the evaporator 45. The detection means 45c is provided. The refrigeration cycle apparatus includes target evaporator temperature calculation means S34 for calculating the target evaporator temperature TEO of the evaporator 45, and means S35 for calculating the control initial value Iouts in the control of the compressor 41. The refrigeration cycle apparatus includes means S45 to S48 for calculating the compressor capacity control value Iout (n) from the temperature deviation E (n) between the target evaporator temperature TEO and the actual evaporator temperature TE. The refrigeration cycle apparatus includes determination means S41 and S41a that determine that the evaporator 45 has reached a predetermined temperature state after controlling the compressor 41 with the control initial value Iouts. Furthermore, the refrigeration cycle apparatus includes compressor control means S49 that holds control of the compressor 41 with the control initial value Iouts until it is determined that the determination means S41 and S41a have reached a predetermined temperature state. Further, the compressor control means S49 starts controlling the compressor 41 with the compressor capacity control value Iout (n) after reaching a predetermined temperature state.

  According to this, even if the time until the predetermined temperature state is changed by the compression of the refrigerant changes depending on the situation, the compressor 41 is controlled by the control initial value Iouts until it is determined that the predetermined temperature state is reached. Hold. Therefore, it is possible to provide a refrigeration cycle apparatus in which overshoot and hunting are more reliably suppressed.

  Next, the refrigeration cycle apparatus calculates temperature deviation Es (n) between the current actual evaporator temperature TE (n) and the actual evaporator temperature TEs when the operation of the compressor 41 is started. (S39). The refrigeration cycle apparatus has a change rate calculation means S40 that calculates a change rate Esdot (n) of the temperature deviation Es (n). The calculated temperature deviation Es (n) is compared with the first predetermined value X, and the calculated temperature deviation change rate Esdot (n) is compared with the second predetermined value Y. From these two comparisons, the determination means (S41) determines that a predetermined temperature state has been reached.

  According to this, the control of the compressor by the control initial value is controlled by the capacity control value Iout (n) of the compressor 41 based on the determination by the two comparisons using the first predetermined value X and the second predetermined value Y. Switch to. Therefore, it is possible to provide a refrigeration cycle apparatus in which overshoot and hunting are reliably suppressed.

  Further, assuming that the current actual evaporator temperature is TE (n) and the actual evaporator temperature when the control of the compressor 41 is started is TEs, the temperature deviation Es (n) is obtained by the following formula 2. The temperature deviation change rate Esdot (n) is obtained by the following Equation 3 when the temperature deviation obtained at a time point before the obtained temperature deviation Es (n) is set to Es (n-1).

(Expression 2) Es (n) = TE (n) −TEs
(Equation 3) Esdot (n) = Es (n) −Es (n−1)
According to this, the temperature deviation Es (n) or the change rate Esdot (n) of the temperature deviation is easily obtained, and it is accurately determined that the evaporator 45 has reached a predetermined temperature state from these obtained values. Can be determined.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following embodiments, the same components as those in the first embodiment described above are denoted by the same reference numerals, description thereof will be omitted, and different configurations and features will be described. In addition, about 2nd Example or less, the same code | symbol as 1st Example shows the same structure, Comprising: The description which precedes is used. In FIG. 7, step S <b> 41 a for determining whether or not there is a response to the actual evaporator temperature TE (n) is determined from condition 1 or condition 2. Condition 1 is that the temperature deviation Es (n) between the current actual evaporator temperature TE (n) and the actual evaporator temperature TEs at the start of the evaporator temperature control is smaller than a predetermined threshold value X. In other words, this is based on the condition that the actual evaporator temperature TE (n) at the present time is lower than the actual evaporator temperature TEs before the operation of the compressor 41 by a threshold value X or more.

  Condition 2 is that the change rate Esdot (n) of the temperature deviation is equal to or less than the threshold value Y. In the second embodiment, the determination in step S41a is performed using only condition 1 or condition 2. That is, the decrease in the evaporator temperature is determined by either the value detected by the actual sensor or the gradient of the temperature decrease.

(Operational effect of the second embodiment)
In the second embodiment, the refrigeration cycle apparatus calculates a temperature deviation Es (n) between the current actual evaporator temperature TE (n) and the actual evaporator temperature TEs when the operation of the compressor 41 is started. It has a calculation means (S39). The refrigeration cycle apparatus has a change rate calculation means S40 that calculates a change rate Esdot (n) of the temperature deviation Es (n). The calculated temperature deviation Es (n) is compared with the first predetermined value X, or the calculated temperature deviation change rate Esdot (n) is compared with the second predetermined value Y. From any of these comparisons, it is determined that the determination means S41 and S41a have reached a predetermined temperature state.

  According to this, when any of the determination conditions is satisfied, the control of the compressor 41 by the control initial value Iouts is switched to the control of the compressor 41 by the compressor capacity control value Iout (n). A refrigeration cycle apparatus in which hunting is suppressed can be provided.

(Third embodiment)
Next, a third embodiment of the present invention will be described. A different part from embodiment mentioned above is demonstrated. In the partial flowchart of FIG. 8, step S81 is added between step S34 and step S35. In step S81, it is determined whether or not the outside air temperature is equal to or lower than a predetermined value. If the outside air temperature is high and no overshoot occurs as in summer, the normal compressor control in step S45 (referred to FIG. 5) is immediately performed. It has migrated. In addition, you may use the vehicle interior temperature cooled with an evaporator instead of outside temperature, or target blowing temperature (TAO).

(Operational effects of the third embodiment)
In the third embodiment, when any of the target blowing temperature (TAO), the outside air temperature, and the indoor temperature cooled by the evaporator 45 is equal to or higher than a predetermined temperature, the determination by the determination means S41 and S41a is not performed. The control start means S81 for immediately starting the control by the capacity control value Iout (n) of the compressor 41 is provided.

  According to this, the control by the capacity control value Iout (n) of the compressor 41 can be started immediately without performing the determination by the determination means S41 and S41a. Therefore, the time until the control by the capacity control value Iout (n) of the compressor 41 is started can be shortened. As a result, it is possible to provide a refrigeration cycle apparatus that speeds up the evaporator temperature and suppresses overshoot and hunting.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. A different part from embodiment mentioned above is demonstrated. In FIG. 9, step S91 is added between step S34 and step S35. In step S91, it is determined whether or not a predetermined time or more has passed from the previous compressor OFF (stop of the compressor 41) to the current compressor ON (operation of the compressor 41). If the predetermined time has not elapsed and the time from the compressor OFF to the compressor ON is short, the delay of the refrigerant flowing into the evaporator 45 can be substantially ignored, so that the normal in step S45 (FIG. 5 to be used) is immediately performed. Shifting to compressor control.

(Operational effect of the fourth embodiment)
In the fourth embodiment, when the time from the previous stop of the compressor 41 to the start of operation of the compressor 41 is not longer than a predetermined time, the determination by the determination means S41 and S41a is not performed, and the capacity control of the compressor 41 is immediately performed. Control by the value Iout (n) is started. This control is performed by the control start unit S91.

  According to this, it is possible to shorten the time until the control by the capacity control value Iout (n) of the compressor 41 is started, to accelerate the decrease in the evaporator temperature, and to suppress overshoot and hunting. Can provide.

(Other embodiments)
In the above-described embodiment, the preferred embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. It is. The structure of the said embodiment is an illustration to the last, Comprising: The scope of the present invention is not limited to the range of these description. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  Although the above embodiment has been described for a vehicle air conditioner of an air conditioner cycle, the evaporator temperature control of an air conditioner other than for a vehicle, the evaporator temperature control in a refrigeration vehicle, the vehicle using an electric compressor of an electric vehicle or a hybrid vehicle Applicable to air conditioning control. And this invention is applicable also to temperature control using a heat pump cycle. In addition to the temperature control of the air conditioning device, the system starts operating and compresses the refrigerant that has a large time delay from the start of operation until the controlled object responds, resulting in a large overshoot or undershoot of the controlled object. Applicable to temperature control.

  In the vehicle air conditioner, by suppressing overshoot, icing of the evaporator can be suppressed and generation of icing odor can be suppressed. In addition, a freezer car is suitable for temperature management of raw materials whose quality deteriorates when frozen.

  Further, an actual evaporator temperature sensor 45c made of a thermistor (not shown) is disposed immediately after the evaporator 45. Thus, the air temperature immediately after passing through the evaporator 45 or the temperature of the fins of the evaporator was detected. Instead of this temperature sensor, a sensor for detecting the refrigerant temperature at the outlet of the evaporator may be an actual evaporator temperature sensor.

45c Actual evaporator temperature detection means (actual evaporator temperature sensor)
E (n), Es (n) S46 temperature deviation, S39 temperature deviation S34 Target evaporator temperature (TEO) calculating means S35 Means for calculating control initial value (Iouts) S39 Temperature deviation (Es (n)) Means S40 means for calculating the rate of change of temperature deviation (Esdot (n)) S41, S41a determining means S45-S49 compressor control means S48 means for calculating compressor capacity control value (Iout (n)) X, Y First predetermined value, second predetermined value

Claims (6)

In the refrigeration cycle apparatus for evaporating the refrigerant compressed by the compressor (41) in the evaporator (45),
An actual evaporator temperature detecting means (45c) for detecting an actual evaporator temperature (TE) by the operation of the evaporator (45);
Target evaporator temperature calculating means (S34) for calculating a target evaporator temperature (TEO) of the evaporator (45);
Means (S35) for calculating a control initial value (Iouts) in the control of the compressor (41);
Means (S45 to S48) for calculating a compressor capacity control value (Iout (n)) from a temperature deviation (E (n)) between the target evaporator temperature (TEO) and the actual evaporator temperature (TE); ,
Determination means (S41, S41a) for determining that the evaporator (45) has reached a predetermined temperature state after controlling the compressor (41) with the control initial value (Iouts);
Until the determination means (S41, S41a) determines that the predetermined temperature state is reached, the control of the compressor (41) by the initial control value (Iouts) is maintained, and the predetermined temperature state is reached. And a compressor control means (S49) for starting the control of the compressor (41) by the capacity control value (Iout (n)) of the compressor. Further, a temperature deviation (Es (n)) between the current actual evaporator temperature (TE (n)) and the actual evaporator temperature (TEs) when the operation of the compressor (41) is started is calculated. Temperature deviation calculation means (S39);
Change rate calculating means (S40) for calculating a change rate (Edot (n)) of the temperature deviation (Es (n)),
The calculated temperature deviation (Es (n)) and the first predetermined value (X) are compared, or the calculated change rate of the temperature deviation (Edot (n)) and the second predetermined value (Y). The refrigeration cycle apparatus according to claim 1, wherein the determination means (S41, S41a) determines that the predetermined temperature state has been reached. Further, a temperature deviation (Es (n)) between the current actual evaporator temperature (TE (n)) and the actual evaporator temperature (TEs) when the operation of the compressor (41) is started is calculated. Temperature deviation calculating means (S39);
Change rate calculating means (S40) for calculating a change rate (Edot (n)) of the temperature deviation (Es (n)),
The calculated temperature deviation (Es (n)) and the first predetermined value (X) are compared, and the calculated rate of change of temperature deviation (Edot (n)) and the second predetermined value (Y) The refrigeration cycle apparatus according to claim 1, wherein the determination means (S41) determines that the predetermined temperature state has been reached. When the actual evaporator temperature at present is TE (n) and the actual evaporator temperature when the control of the compressor (41) is started is TEs, the temperature deviation Es (n) is Es (n ) = TE (n) -TEs
With the formula of
When the temperature deviation obtained at a time point before the obtained temperature deviation Es (n) is set to Es (n−1), the change rate Esdot (n) of the temperature deviation is set to Esdot (n) = Es (N) -Es (n-1)
The refrigeration cycle apparatus according to claim 2 or 3, wherein the refrigeration cycle apparatus is obtained by the following formula.   When any of the target blowing temperature (TAO), the outside air temperature, and the indoor temperature cooled by the evaporator (45) is equal to or higher than a predetermined temperature, the determination by the determination means (S41, S41a) is not performed. The refrigeration according to any one of claims 1 to 4, further comprising control start means (S81) for immediately starting control by the capacity control value (Iout (n)) of the compressor (41). Cycle equipment.   When the time from the previous stop of the compressor (41) to the start of operation of the compressor (41) is not a predetermined time or more, the determination by the determination means (S41, S41a) is not performed, and the compressor (41 The refrigeration cycle apparatus according to any one of claims 1 to 4, further comprising control start means (S91) for starting control based on an ability control value (Iout (n)).

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