JPH0390430A - Automotive heat pump device - Google Patents

Abstract

PURPOSE:To improve the rising characteristic at the time of starting by recovering the heat of the exhaust gas and warming the engine cooling water to enable the immediate heating, and while controlling the flow quantity of the engine cooling water and the exhaust gas to an exhaust gas heat exchanger for changing the exhaust gas with the heat. CONSTITUTION:An engine 1 and a radiator 4 are connected through cooling water flow-in/out pipes 2, 3 to fore a cooling water circuit, and a pipe ld separated from the flow-out pipe 3 is connected to an exhaust gas heat exchanger 7 provided in a passage separated from an exhaust pipe 8 of the engine 1. The engine cooling water heated by this heat exchanger 7 is led into a refrigerant heating heat exchange 18 through a pipe 15 and is returned to the engine 1 through a pipe 17 after giving the heat to the refrigerant in a heat pump circuit 26. The heat pump circuit 26 is formed by connecting the refrigerant heating heat exchanger 16, a compressor 28 to be driven by the engine, an accumulator 29, a fourway switching valve 30, an outdoor heat exchanger 31, an indoor heat exchanger 32 and an electric pressure reducing valve 33.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat pump device for an automobile that circulates a refrigerant between an indoor heat exchanger and an outdoor heat exchanger to cool and heat the interior of a vehicle.

(Prior art) In this type of automotive heat pump device, if the outside air is low temperature, the outside heat exchanger may not be able to pump up enough heat from the outside air, and a sufficient feeling of heating may not be obtained. .

For this reason, in the apparatus disclosed in Japanese Patent Application Laid-open No. 61-12420, a configuration is disclosed in which a third heat exchanger is provided in the cooling water circuit to exchange heat with engine cooling water during heating operation.

However, even with this method, there is a problem in that the engine cooling water is not yet sufficiently warmed when the engine is started, and immediate heating cannot be obtained.

In addition, after obtaining the predetermined temperature after heating operation,
As shown in Publication No. 175407, a configuration is disclosed in which heating temperature is adjusted by changing the amount of air sent to an indoor heat exchanger in steps according to temperature changes.

However, when the amount of air blown is changed in steps, there is a problem that the occupants near the air outlet for indoor heat exchange feel uncomfortable due to the change in the amount of air, which impairs the feeling of air conditioning.

(Problem to be Solved by the Invention) Therefore, this invention adopts a method of heating the refrigerant with engine cooling water, but it is also possible to recover the heat of exhaust gas and warm the engine cooling water to obtain immediate heating. In addition, by adjusting the supply of engine cooling water to the exhaust gas heat exchanger that exchanges heat with exhaust gas, and adjusting the amount of exhaust gas flowing into the exhaust gas heat exchanger, the start-up characteristics at startup are improved. The purpose is to protect the exhaust heat exchanger.

(Means for Solving the Problems) A heat pump device for an automobile according to the present invention includes an outdoor heat exchanger that exchanges heat between a refrigerant and outside air, an indoor heat exchanger that exchanges heat between the refrigerant and indoor air or outside air, and an accumulator. A four-way switching valve that switches the refrigerant circuit, a compressor that pressurizes the refrigerant, a refrigerant heating heat exchanger that heats the refrigerant with engine cooling water during heating operation, and an engine cooling system that supplies the engine cooling from the engine to the refrigerant heating heat exchanger. The engine is characterized in that it has an exhaust gas heat exchanger that exchanges heat with water and exhaust gas, and is provided with a control means that controls the amount of engine cooling water introduced into the exhaust gas heat exchanger.

Furthermore, the exhaust gas heat exchanger may be designed to adjust the temperature of the refrigerant heated by the refrigerant heating heat exchanger by controlling the inflow amount of the exhaust gas introduced.

(Function) According to the automobile heat pump device according to claim 1,
Engine cooling water is heated in the exhaust gas heat exchanger, so heating can be achieved immediately.

In addition, by controlling the amount of engine cooling water supplied to the exhaust gas heat exchanger, the amount of engine cooling water at a relatively high temperature is restricted, especially during the start-up period when starting the engine. It is now possible to supply the refrigerant to the refrigerant heating heat exchanger, and has excellent immediate effect.In addition, under normal conditions, the cooling water temperature in the refrigerant heating heat exchanger can be adjusted, The temperature of the refrigerant with which heat is exchanged can be uniformly set to a desired value at all times.

In the automobile heat pump device according to the second aspect, heating of the cooling water temperature in the exhaust gas heat exchanger is prevented by controlling the amount of exhaust gas introduced into the exhaust gas heat exchanger. This not only protects the exhaust gas heat exchanger and the heater core, but also provides immediate heating as in the first aspect of the invention.

(Examples) Examples of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, cooling water inflow/outflow vibes 2 and 3 are connected to the engine, and a cooling water circuit is constituted by a circulation path including a radiator 4. When the cooling water temperature is low, the radiator 4 Water thermometer 5 that short circuits without reaching
is provided.

6 is a water pump provided within the engine 1. 7 is an exhaust gas heat exchanger that exchanges heat between engine exhaust gas and engine cooling water, and the exhaust gas is passed through the exhaust pipe 8.
The cooling water is introduced through the introduction passage 9 and returned to the exhaust pipe 8 from the discharge passage 10, and the cooling water introduced into the exhaust gas heat exchanger 7 is heated by heat exchange. An exhaust bypass door 12 for introducing or blocking exhaust gas is driven by an actuator 13 into the introduction passage 9 into which exhaust gas is introduced, and its opening degree is controlled and closed when unnecessary.

A pipe 14 branched from the outflow pipe 3 is connected to the exhaust gas heat exchanger 7 so that engine cooling water flows therein.

Then, the engine cooling water heated by the exhaust gas heat exchanger 7 is transferred to the refrigerant heating heat exchanger 1 described below in the vibrator 15.
6, and the vibrator 1 is introduced from the refrigerant heating heat exchanger 16.
It is piped so as to be returned to the engine 1 at 7. In addition, from Vibe 2.3, there is a heater core 18 for heating the vehicle interior.
A circuit is formed that branches to the pipe 20 from the engine 1, and from the heater core 18 to the pipe
It is piped to return to the engine 1 via 9.

The engine cooling water flows into the heat exchanger 16 for heating the refrigerant or the heater core 18 for heating the vehicle interior through the first valve 35 and the fourth valve 35.
It is controlled by the opening/closing operation of the valve 36.

Further, a throttle 24 is provided in parallel with the third valve 22 that controls the inflow of engine cooling water into the exhaust gas heat exchanger 7 .

On the other hand, the heat pump circuit 26 includes a variable capacity compressor 28 connected by a magnetic clutch 27 in the driving engine 1, an accumulator 29, a four-way switching valve 30', an outdoor heat exchanger 31, and a pair thereof. An indoor heat exchanger 32 and an electric pressure reducing valve 33 are connected by piping. The heat pump circuit 26 includes a four-way switching valve 30
In the connected state shown by the broken line in FIG. 1, the heating mode is set and the blower 34 blows warm air from the indoor heat exchanger 32. When the connection is switched as shown by the solid line, the indoor heat exchanger 32 enters the cooling mode. Cold air is blown out from 32.

With the above configuration, in the heating mode, when the cooling water temperature of the engine 1 is not yet at a sufficient temperature after starting the engine, the heat pump mode is adopted since it is not suitable for heating using the heater core 18. For example, if a passenger sets the air conditioning panel to heating mode when the coolant temperature is below 50 degrees Celsius, when the engine coolant temperature is low, it will automatically switch to the heating mode that uses the heat pump, and the engine coolant will be heated by exhaust gas heat. After being supplied to the exchanger 7 and heated by the heat of the exhaust gas, the engine cooling water heats the refrigerant of the heat pump in the refrigerant heating heat exchanger 16.

On the other hand, the refrigerant heated in the refrigerant heating heat exchanger 16 is sent to the indoor heat exchanger 32 through the four-way switching valve 30, as shown by the arrow hole in FIG. 1, where it exchanges heat with the air. to warm the room. The refrigerant after heat exchange in the indoor heat exchanger 32 is sent to the outdoor heat exchanger 31 to pump up heat from the outside air, then passes through the four-way switching valve 30, the heating heat exchanger 16, and the accumulator 29, and is returned to the compressor 28. It will be done.

Engine cooling water is introduced into the refrigerant heating heat exchanger 16 as described above, and the engine cooling water is heated in the exhaust gas heat exchanger 7 and then heats the refrigerant. Therefore, the refrigerant can immediately send out warm air at a relatively high temperature by pumping up the heat of the outside air by the outdoor heat exchanger 31 and using the refrigerant heating heat exchanger together. In particular, when the engine is started, the temperature of the cooling water is low, so the flow rate can be controlled by the third valve 22 to send relatively warm engine cooling water.

When the engine coolant temperature reaches a predetermined value,
The mode switches to the normal heating mode using the heater core 18.

In this case, the fourth valve 36 is opened, the first valve 35 is closed, and cooling water is supplied to the heater core 18.

Note that engine cooling water is heated in the exhaust gas heat exchanger 7, and if the temperature of the cooling water is heated above a predetermined value, it may cause damage to the heater core 18. In this case, the temperature of the cooling water to be heated is controlled by controlling the opening degree of the exhaust bi-bus door 12.

Next, the control device 38 that controls the temperature of the refrigerant heating heat exchanger 16 will be described.

As shown in FIG. 2, in the control device 38, the microcomputer 39 has each temperature sensor T0 to T,
It is connected via a converter 40, and the temperature measurement signal is converted into an input signal and input to the microcomputer 39.

As shown in FIG. 1, the temperature detector T0 is provided near the outdoor heat exchanger 31, and detects the outside air temperature and outputs a detection signal t0.
It is designed to emit. Similarly, detection signal 1. The temperature sensor T that emits the temperature detects the inlet refrigerant temperature of the outdoor heat exchanger 31, and the temperature sensor Tz that emits the detection signal t2 detects the outlet refrigerant temperature of the indoor heat exchanger and emits the detection signal t3. The temperature sensor T4 detects the temperature of the refrigerant in the four-way switching valve and emits a detection signal t4.
The temperature sensor T, which emits the temperature of the exhaust gas heat exchanger, detects the outlet temperature of the exhaust gas heat exchanger, and the temperature detector T6, which emits the detection signal t6, detects the outlet temperature of the engine coolant, and the temperature detector T7, which emits the detection signal t. detects the temperature of the air passing through the indoor heat exchanger 32, and a temperature detector T8 that emits a detection signal t8 detects the temperature of the air between the outdoor heat exchanger 31 and the radiator 4.

The microcomputer 39 includes an air mix store drive circuit 41 that controls the drive of a mix door (not shown) provided in the air conditioning duct, and a blower motor that controls the drive of the blower 34 provided in the indoor heat exchanger. A drive circuit 43, a magnetic clutch drive circuit 44 that controls the drive of the compressor 28, a discharge amount adjustment device drive circuit 45 that adjusts the compressor discharge amount, an electric pressure reducing valve drive circuit 46 that controls opening and closing of the electric pressure reducing valve 33, and a four-way switching valve. A drive circuit 47, a solenoid valve drive circuit 48, 49, 50, 51 that controls the opening and closing of the multi-valve (electromagnetic valve) 22, 35, 36, 37, and a bypass door drive circuit 52 that controls the opening degree of the exhaust bypass door 12. They are connected to each other, and drive control signals are sent to each.

Next, control operations in the control device will be explained.

As shown in FIG.
In step 01, an initial value to be compared is set corresponding to each temperature measurement value, and then the process moves to step 102, where each detection signal from the multi-temperature detectors T0 to Tll is read and the process is performed in step 1.
Move to 03.

In step 103, it is determined whether the outside air temperature t0 detected by the temperature sensor T0 is higher than a preset temperature of 10°C. If the outside air temperature t0 is higher than 10°C, the process first moves to step 104, and if it is below 10°C, the process moves to step 111.

In step 104, a closing signal is issued to the exhaust bypass drive circuit 52 to close the exhaust bypass door 12, and the process proceeds to step 105.

In step 105, an OFF signal is issued to the magnetic clutch drive circuit 44 to stop driving the compressor 28 and stop the operation of the heat pump device. Thereafter, the process moves to step 106.

In step 106, a closing signal for the electric pressure reducing valve 33 is issued to the electric pressure reducing valve drive circuit 46 to close the electric pressure reducing valve 33, and the process proceeds to step 107.

In step 107, a closing signal is issued to the first electromagnetic valve drive circuit 48 to close the first valve 35, and the introduction of engine cooling water to the refrigerant heating heat exchanger 16 is stopped.
Move to 08.

In step 108, an open signal is issued to the third electromagnetic valve drive circuit 50 to open the third valve 22, and then in step 109
Similarly, an open signal is issued to the second electromagnetic valve drive circuit 49 to open the second valve 37, and in steps 1] and 0, the fourth valve is opened.
After closing the valve 36, the process returns to step 10 and returns to step 10.
Move to 2.

Therefore, when the outside air temperature is relatively high, the operation of the exhaust gas heat exchanger 7 is stopped, and the introduction of engine cooling water to the refrigerant heating heat exchanger 16 is also stopped.

On the other hand, if the outside air temperature t0 is 10°C or less in step 103, the process moves to step 111, where it is determined whether the engine cooling water temperature t is higher than 75°C. If the temperature is higher than 75°C, the process moves to step 104 and the heat pump operation is stopped. If the temperature is 75° C. or lower, the process moves to step 112.

In step 112, the first valve 35 is opened and the second valve 37 is closed at the same time to introduce cooling water from the exhaust gas heat exchanger 7 to the refrigerant heating heat exchanger 16. Supplementary heating is performed at step 7.

Then, the process moves to step 113.

In step 113, the outlet temperature t of the exhaust gas heat exchanger 7,
It is determined whether or not the temperature is higher than 100°C. If the temperature is lower than 100°C, the process moves to step 114 to open the exhaust bypass door 12, and then moves to step 115. 10
If the temperature is higher than 0''C, the process moves to step 116, and the engine cooling water is introduced into the exhaust gas heat exchanger 7 with the exhaust bypass door 12 closed. The heat exchange amount is controlled by controlling the inflow amount.Then, the process moves to step 115.

In step 115, the cooling water temperature t at the engine outlet
It is determined whether or not , is higher than 40°C, and if it is higher,
Proceeding to step 117, the third valve 22 is opened by a predetermined amount,
Cooling water is introduced into the exhaust gas heat exchanger 7. If the temperature is 40° C. or lower, the process proceeds to step 118, where the third valve 22 is closed to reduce the amount of cooling water introduced into the exhaust gas heat exchanger 7. Here, the temperature of the cooling water flowing out from the exhaust gas heat exchanger 7 is controlled by controlling the amount of flow into the exhaust gas heat exchanger 7.

Subsequently, in step 119, it is determined whether the cooling water temperature t at the engine outlet is lower than 0°C. If high, proceed to the next step 123 shown in FIG.
to move to. If the temperature is low, the process moves to step 120, where it is further determined whether the temperature is higher than -10°C. If the temperature is lower than -10°C, the process moves to step 121, and if the temperature is -10°C or higher, the process moves to step 123 via (2).

In step 121, the magnetic clutch 27 is turned off to stop driving the compressor 28, and then in step 122, the electric pressure reducing valve 33 is closed, and then the process returns to step (2).

Therefore, when the outside air temperature is very low, heat pump heating cannot be used, and the heat pump is stopped.

In step 123, as shown in FIG. 4, it is compared whether the outlet temperature T2 of the indoor heat exchanger 32 is higher than 80°C.

If the temperature is high, proceed to step 121 described above via ■ (see Figure 1), stop driving the heat pump device, and proceed to step 8.
If the temperature is below 0°C, the process moves to step 124.

In step 124, it is determined whether the refrigerant temperature t3 in the four-way switching valve 30 is higher than 140°C. If the temperature is higher than 140° C., the process moves to step 121 to stop driving the heat pump device, and if it is below 140°C, the process moves to step 125.

In step 125, the temperature t measured by the temperature detector T7 provided in the indoor heat exchanger 32 and the predetermined temperature Δ1
+ (for example, 5℃) is the engine cooling water temperature th
It is determined whether it is higher or lower.

If so, proceed to step 126 and t.

In the following cases, the process moves to step 127.

In step 126, an air mix door (not shown) is opened to allow air to pass to the heater core 18, and in step 127, the air mix door is closed to prevent air from passing to the heater core 18. This prevents cold air from blowing out because ventilation to the heater core 18 is not allowed until the cooling water temperature becomes sufficiently high. Then, the process moves to step 128 via (2).

In step 128, the opening degree of the electric pressure reducing valve 33 is calculated, and the result is output to the electromagnetic valve drive circuit 46.
Move to 29. As shown in FIG. 7, this calculation is calculated from the relationship between the exhaust bypass outlet temperature t and the target value t19 of the low-pressure refrigerant temperature.
When decreasing, it is calculated based on B.

In step 129, the magnetic clutch 27 is turned on to drive the compressor 28, and the process proceeds to step 130. This puts the heat pump device into operation.

In step 130, counting of time S is started, and then the process moves to step 131.

In step 131, it is determined whether the time T has exceeded 10 minutes. If it has, the process moves to step 132, and if it has not, the process moves to step 133.

In step 132, the air volume of the blower 34 is set to a predetermined value, and then the process moves to step 134.

In step 134, it is determined whether or not the outdoor heat exchanger 31 is frozen, and if it is frozen, the process proceeds to step 121 described above via ■ to stop the drive of the heat pump, and if it is not frozen, the process proceeds to step 121 described above. Then, the process moves to step 135.

Judging whether or not it is frozen is based on whether the air temperature t after the outdoor heat exchanger is the inflow temperature of the refrigerant into the outdoor heat exchanger 1. and the predetermined temperature Δt2, that is, 18>1. +Δ
It is determined whether or not t2 is satisfied, and if it is, freezing is determined, and if it is not, it is determined that it is not freezing. still,
In this case, the temperature at which the refrigerant flows into the outdoor heat exchanger 31 is 1. may be replaced with the outdoor temperature t0.

In step 135, a low pressure refrigerant temperature target value is calculated. As shown in FIG. 8, this calculation is performed because the relationship between the outside air temperature and the low pressure refrigerant temperature is approximately proportional to the outside air temperature. After the calculation, the process moves to step 136 via (2).

On the other hand, in step 133, the air volume of the blower is calculated, and based on the calculated value, an output signal is issued to the blower motor drive circuit 43 to control the output of the blower motor. As shown in FIG. 9, this calculation is performed based on line A when the air volume increases, and based on line B when it decreases, in relation to the high-pressure refrigerant temperature t2 measured by the temperature measuring device T2. and,
After the output control, the process moves to step 137.

In step 137, it is determined whether the blower air volume is equal to the set value, and if they are equal, the process moves to step 138, and if they are not equal, the process moves to step 139.

In step 138, the discharge amount of the compressor 28 is calculated, and the compressor discharge amount adjustment drive circuit 45
After issuing an output signal, the process moves to step 140 via (2). In the calculation in step 138, as shown in FIG. 10, the discharge amount of the compressor is calculated in relation to the value obtained by subtracting 70° C. from the high-pressure refrigerant temperature. and,
Based on the calculated discharge amount, an output signal is issued to the compressor discharge amount adjustment circuit, and step 140-0 is performed via ■.
Transition.

On the other hand, in step 139, the discharge amount of the compressor 28 is calculated as in step 138, and an output signal is issued to the compressor discharge amount adjustment drive circuit 45 based on this calculated value, but in this case, as shown in FIG. , low pressure refrigerant temperature 1. The discharge amount of the compressor is calculated in relation to the value obtained by subtracting -10°C from the temperature. After the calculation, the process moves to step 140 via (2) in the same way as step 138 described above.

As shown in FIG. 6, following step 135 described above,
In step 136, the discharge amount of the capacitor is calculated. As shown in FIG. 12, the calculation calculates the discharge amount of the compressor (referred to as E) in relation to the value obtained by subtracting the target value from the inlet temperature t of the outdoor heat exchanger 31. continue,
The process moves to step 140.

In step 140, the inlet temperature 1. It is determined whether or not the temperature is smaller than -20°C, and if it is smaller, the process moves to step 121 (Fig. 1) described above via ■ to stop driving the heat pump, and if it is more than -10°C, it moves to step 14.
Move to 1.

In step 141, the discharge amount of the compressor is calculated, and the process moves to step 142. The calculation here is step 13
8, the discharge amount F of the compressor is calculated in relation to the value obtained by subtracting 70° C. from the high-pressure refrigerant temperature.

In step 142, the aforementioned calculated quantities E and F are compared and the smaller value is output. Therefore, by changing the discharge amount of the compressor, the air temperature can be adjusted without changing the air amount. Then, the process moves to step 102 (see FIG. 3) via (2), and the above-described routine is repeated again.

Needless to say, hysteresis is provided in each determination step based on each temperature described above, and a predetermined width is provided for the determination.

(Effects of the Invention) According to the invention set forth in claim 1, since the engine cooling water is heated by the exhaust gas heat exchanger, heating can be achieved immediately.

In addition, by controlling the amount of engine cooling water supplied to the exhaust gas heat exchanger, the amount of engine cooling water at a relatively high temperature is restricted, especially during the start-up period when starting the engine. It is now possible to supply the refrigerant to the refrigerant heating heat exchanger, and has excellent immediate effect.In addition, under normal conditions, the cooling water temperature in the refrigerant heating heat exchanger can be adjusted, The temperature of the refrigerant with which heat is exchanged can be uniformly set to a desired value at all times.

In the automobile heat pump device according to the second aspect, heating of the cooling water temperature in the exhaust gas heat exchanger is prevented by controlling the amount of exhaust gas introduced into the exhaust gas heat exchanger. This not only protects the exhaust gas heat exchanger and the heater core, but also provides immediate heating as in the first aspect of the invention.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram according to an embodiment of the present invention, FIG. 2 is a functional block diagram showing the configuration of a control device, and FIGS. 3 to 6 are flowcharts showing the main routine of the control device.
FIG. 7 is a graph that is the basis of the calculation in step 128, FIG. 8 is a graph that is the basis of the calculation in step 135, FIG. 9 is a graph that is the basis of the calculation in step 133, and FIG. 10 is the graph that is the basis of the calculation in step 135. A graph diagram that is the basis of the calculation in step 138, FIG. 11 shows step 139
FIG. 12 is a graph diagram that is the basis of the computation in step 136. 7... Exhaust gas heat exchanger, 12... Exhaust bypass door (means for controlling the amount of exhaust gas introduced),
16... Heat exchanger for heating refrigerant, 22...
・Third valve (means for controlling the supply amount of cooling water), 28・
...Compressor, 29...Accumulator, 31...Outdoor heat exchanger, 32...
- Indoor heat exchanger, 38... Control device. Fig. 6 A Fig. 7 Fig. 8 Tato No. 9 Fig. 10 (t2-70)

Claims (2)

[Claims] (1) An outdoor heat exchanger that exchanges heat between the refrigerant and outside air, an indoor heat exchanger that exchanges heat between the refrigerant and indoor air or outside air, an accumulator, a four-way switching valve that switches the refrigerant circuit, and a compressor that pressurizes the refrigerant. It has a refrigerant heating heat exchanger that heats a refrigerant with engine cooling water during heating operation, and an exhaust gas heat exchanger that exchanges heat with exhaust gas and engine cooling water supplied from the engine to the refrigerant heating heat exchanger. A heat pump device for an automobile, further comprising a control means for controlling an amount of engine cooling water introduced into the exhaust gas heat exchanger. (2) an outdoor heat exchanger that exchanges heat between the refrigerant and outside air, an indoor heat exchanger that exchanges heat between the refrigerant and indoor air or outside air, an accumulator, a four-way switching valve that switches the refrigerant circuit, and a compressor that pressurizes the refrigerant; a refrigerant heating heat exchanger that heats a refrigerant during heating operation; and an exhaust gas heat exchanger that exchanges heat with exhaust gas for engine cooling water supplied from the engine to the refrigerant heating heat exchanger; A heat pump device for an automobile, characterized in that it is provided with a control means for controlling the amount of introduced exhaust gas to be heat exchanged with a gas heat exchanger.