JP2001004247A - Ignition timing control method for heat pump driving engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent frosting at the time of heating operation by delaying the ignition timing behind an ignition timing set by a base map if the outer air temperature is lower than a specified level at the time of heating operation. SOLUTION: A decision is made whether a heat pump is under heating operation (S61), and if it is under heating operation, outer air temperature is checked against a specified level (S63). Temperature of low pressure side refrigerant piping coupled to the refrigerant inlet side of a compressor is then detected and low pressure saturation temperature is checked against a specified level T deg.C (S64). If it is lower than frosting point, control map of a fuel control valve is switched to a base map (S65) and checked against a delay angle region preset depending on the r.p.m. of engine or throttle opening (S66). A delay angle is then operated (S67) based on the outer air temperature and low pressure saturation temperature and if the delay angle is lower than an allowable level, ignition timing of the base map is delayed by the delay angle (S68).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for controlling the ignition timing of an engine used in a heat pump type air conditioner or the like.

[0002]

2. Description of the Related Art A heat pump type air conditioner driven by a gas engine which obtains a high heating capacity by recovering heat of an exhaust gas of an engine has been put to practical use. In such a heat pump type air conditioner, a compressor is driven by an engine, a refrigerant is circulated through an outdoor heat exchanger, an indoor heat exchanger, an expansion valve and the like to form a refrigerant circuit, and the circuit is switched by a four-way valve and the like. Cooling and heating are performed by the indoor heat exchanger. This engine is provided with an exhaust gas heat exchanger and recovers exhaust heat to heat the refrigerant, so that a high heating capacity can be obtained in the refrigerant circuit even when the outside air temperature is low.

[0003] In such a heat pump type air conditioner, the outdoor heat exchanger functions as an evaporator at the time of heating, and removes the heat of the outside air to evaporate the refrigerant. In this case, if the outside air temperature is low, frost adheres to the outdoor heat exchanger and the heat absorption efficiency is reduced, and the evaporation function is impaired, so that an appropriate refrigerant circuit is not formed and heating may not be performed. In order to remove the adhering frost, it is necessary to temporarily switch to the cooling cycle, which lowers the use efficiency. Therefore, it is desired to prevent frost.

On the other hand, a heat pump type air conditioner driven by a gas engine is disclosed in Japanese Patent Application Laid-Open No. 8-49942. The heat pump air conditioner described in this publication has a refrigerant circuit that circulates a refrigerant by a compressor driven by an engine and a cooling water that circulates a cooling water that cools the engine for the purpose of increasing the heating capacity during low-temperature heating. The refrigerant circuit is provided with an expansion valve, an indoor heat exchanger and an outdoor heat exchanger, and the cooling water circuit is provided with an exhaust gas heat exchanger. In the engine-driven heat pump device configured to exchange heat with the liquid refrigerant in the accumulator, control means for controlling the amount of engine waste heat according to the high-pressure side pressure of the refrigerant during low-temperature heating is provided. As one of the means for controlling the amount of waste heat of the engine at the time of low-temperature heating, ignition timing control is performed, and the amount of waste heat recovered is reduced by retarding the ignition timing according to the crank angle by the high pressure side of the refrigerant and the engine speed. In many cases, methods for increasing the heating capacity are described.

[0005]

However, the above publication discloses a technique for retarding the ignition timing in order to enhance the heating capacity, and does not consider prevention of frost during heating. Therefore, the ignition timing is controlled based on the high-pressure side pressure of the refrigerant and the engine speed related to the heating capacity without being based on the ambient conditions directly related to the frost such as the outside air temperature and the pipe temperature. Further, simply retarding the ignition timing may cause a misfire in the lean burn operation, so it is necessary to perform fuel control together. Furthermore, depending on the operating range, not only the misfire limit is taken into consideration, but also operating conditions such as output, combustion efficiency and exhaust heat exchange rate are taken into account, and the ignition timing retard amount is adjusted according to the engine speed and throttle opening. Is desirably set appropriately.

The present invention has been made in consideration of the above-mentioned prior art, and aims to prevent frost during heating and ensure stable combustion in a refrigerant circuit constituting a heat pump.
It is another object of the present invention to provide a method for controlling an ignition timing of a heat pump driving engine that can obtain an optimum operation state according to an operation region.

[0007]

According to the present invention, there is provided an exhaust gas heat exchanger and a refrigerant heat exchanger for heating a refrigerant with cooling water passing through the exhaust gas heat exchanger. In a method for controlling the ignition timing of a heat pump driving engine in which the ignition timing is controlled by a base map based on a preset engine speed and a throttle opening, when the outside air temperature is equal to or lower than a predetermined value during the heating operation, the ignition timing is set to An ignition timing control method for a heat pump driving engine, wherein the ignition timing is retarded from the ignition timing set in the base map.

According to this configuration, when the outside air temperature is lower than the predetermined value during the heating operation and there is a possibility of frost,
The ignition timing is retarded from the base map value, the exhaust gas temperature rises, and the amount of heat recovery in the exhaust gas heat exchanger increases,
This heat is supplied to the refrigerant via the refrigerant heat exchanger to increase the temperature of the refrigerant, thereby preventing frost in the outdoor heat exchanger. Thereby, during normal operation, the ignition timing of the base map can be set so as to obtain an optimal operation state with respect to operation states such as combustion efficiency and output, and the ignition timing can be retarded when frost prevention is required. .

When the ignition timing is retarded, the amount of work of the combustion gas with respect to the piston decreases, the output decreases, and the exhaust gas temperature increases accordingly. This increase in exhaust gas temperature increases the amount of exhaust heat recovered in the exhaust gas heat exchanger. In this case, the engine speed is reduced by an amount corresponding to the output reduction due to the load of the compressor as the engine output decreases. However, the decrease in the output and the rotation speed can be compensated by increasing the fuel supply amount.

[0010] The present invention further provides an exhaust gas heat exchanger,
A heat pump driving engine having a refrigerant heat exchanger for heating the refrigerant with cooling water passing through the exhaust gas heat exchanger, and performing ignition timing control based on a base map based on a preset engine speed and throttle opening Wherein the ignition timing is retarded from the ignition timing set in the base map when the low-pressure saturation temperature of the refrigerant is equal to or lower than a predetermined value during the heating operation. To provide an ignition timing control method.

According to this configuration, the temperature of the low-pressure side pipe (low-pressure saturation temperature) sent to the compressor during the heating operation.
Is lower than the predetermined value and there is a risk of frost,
As in the case where the outside air temperature is low, the ignition timing is retarded from the base map value, the exhaust gas temperature rises, the heat recovery amount in the exhaust gas heat exchanger increases, and this heat is transferred to the refrigerant heat exchanger. The refrigerant is supplied to the refrigerant via the refrigeration system, and the refrigerant temperature rises to prevent frost in the outdoor heat exchanger.

In a preferred embodiment, the ignition timing retardable amount is set according to the engine speed and / or the throttle opening.

According to this configuration, the ignition timing retardable amount is set for each operation region based on at least one of the engine speed and the throttle opening, so that the operation state is optimally maintained according to the operation region. In addition, ignition timing control for preventing frost can be performed.

According to the present invention, there is further provided an exhaust gas heat exchanger,
A heat pump driving engine having a refrigerant heat exchanger for heating the refrigerant with cooling water passing through the exhaust gas heat exchanger, and performing ignition timing control based on a base map based on a preset engine speed and throttle opening In the ignition timing control method, when the engine speed is equal to or higher than a predetermined speed and the high-pressure saturation temperature of the refrigerant is equal to or lower than a predetermined value during the heating operation, the ignition timing is retarded from the ignition timing set in the base map. An ignition timing control method for a heat pump driving engine is provided.

[0015] According to this configuration, at the time of high output of the engine at high speed during the heating operation, if the pipe temperature (high-pressure saturation temperature) on the compressor outlet side does not reach a predetermined high temperature and high output cannot be obtained, ignition is performed. By retarding the timing, the exhaust gas temperature rises and the amount of heat recovery in the exhaust gas heat exchanger increases, and this heat is supplied to the refrigerant through the refrigerant heat exchanger, and the refrigerant temperature rises and the refrigerant pressure rises. And the heating capacity is improved.

In a preferred embodiment, the engine includes an exhaust gas heat exchanger, and a refrigerant heat exchanger for heating the refrigerant with cooling water passing through the exhaust gas heat exchanger. Timing control and fuel supply control are performed by an ignition timing control base map and a fuel control base map, respectively, and the fuel control base map is rewritten to a lean side by learning. In the heating operation, if the outside air temperature or the low pressure saturation temperature is equal to or lower than a predetermined value, the ignition timing is retarded from the ignition timing set in the ignition timing base map, and the first fuel control base before rewriting is set. A method for controlling the ignition timing of an engine for driving a heat pump characterized by performing fuel control by returning to the map. To.

According to this configuration, when there is a possibility of frost during heating, the ignition timing is retarded and the fuel is returned to the first base map to be enriched.
There is no risk of misfire due to retarded ignition timing, and the amount of exhaust heat recovery can be increased while maintaining stable combustion to prevent frost.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a gas engine heat pump air conditioning system to which the present invention is applied.

This air conditioning system comprises an outdoor unit 60 and a plurality of indoor units 61 (only one is shown in the figure), in which the gas engine 1 is provided.
The heat pump refrigerant cycle 2 driven by the gas engine 1 includes an outdoor unit 60 and an outdoor unit 61.
Composed across

The gas engine 1 has an intake passage 4 connected to an air cleaner 3, and a mixer 5 is provided on the intake passage 4. A throttle valve 6 is provided on the downstream side of the gas mixing section of the mixer 5, and adjusts an amount of a mixture of outside air and gas fuel which is taken in from an intake port 18 and supplied through an air cleaner 3. A fuel supply pipe 7 is connected to a gas mixing section of the mixer 5 to form a gas mixture. A gas fuel control valve 8 for adjusting the flow rate of gas fuel supplied to the mixer 5 and a zero governor 9 for adjusting gas pressure to atmospheric pressure are provided on the fuel supply pipe 7. (Not shown). The gas fuel control valve 8 is feedback-controlled by the CPU as described later.

An exhaust pipe 12 is provided on the exhaust side of the gas engine 1. An exhaust gas catalyst 13 and an exhaust gas heat exchanger 14 are provided on the exhaust pipe 12, and a silencer 15 and a drain separator 16 are further provided downstream thereof. Exhaust gas is discharged from an exhaust outlet 17. The drain separator 16, the silencer 15, and the exhaust gas heat exchanger 14 are connected to a neutralizer 19, which neutralizes the acidic drain water to form a drain outlet 2.
Discharge from 0 to the outside.

An oil tank 22 is connected to an oil pan 21 at the bottom of the gas engine 1, and oil is supplied by an oil supply pump 23. The oil circulates through the engine by an oil pump (not shown). Reference numeral 11 denotes an oil separator for separating oil in the blow-by gas.

Two compressors 25 are connected to a crankshaft (not shown) of the gas engine 1 via a clutch 24. Each compressor 25 is connected to a refrigerant inlet pipe 27 and a refrigerant outlet pipe 28 through which a refrigerant made of de-fluorocarbon gas or the like circulates. A flexible pipe 2 is provided in the refrigerant inlet pipe 27 and the refrigerant outlet pipe 28 around the compressor in order to arrange the pipes compactly and to absorb stress and vibration.
6 are interposed. An oil separator 29 is mounted on the refrigerant outlet pipe 28 side, and is connected to the four-way valve 30 on the downstream side. The oil separator 29 separates oil and liquid refrigerant from the compressed refrigerant gas, and returns them to the accumulator 35 through the return pipe 33. The four-way valve 30 has four ports a, b, c, and d, and the connection between the ports is switched during cooling and heating.

At the time of heating, as shown, port a and port b are connected, and port c and port d are connected. As a result, the compressed refrigerant gas discharged from the compressor 25 is condensed through the indoor heat exchanger 31, and the condensed heat is released into the room to heat the room. The condensed refrigerant is decompressed through the expansion valve 52 and evaporates through the outdoor heat exchanger 32 via the HIC 51. The evaporated refrigerant passes through the ports c and d of the four-way valve 30 and enters the accumulator 35 via the plate heat exchanger 34 or the bypass pipe 45. A sub-accumulator 46 is provided in parallel with the accumulator 35. The refrigerant of the accumulator 35 is the capillary tube 4
8, 49, 50 and the refrigerant inlet pipe 2 through the throttle 47 and the like.
7 sucks into the compressor 25.

Reference numeral 80 denotes a refrigerant pipe extending from the four-way valve 30 to the expansion valve 52 through the indoor heat exchanger 31.
Reference numeral 1 denotes a refrigerant pipe extending from the expansion valve 52 to the subcool outdoor heat exchanger 32a via the HIC 51, and reference numeral 82 denotes a refrigerant pipe which diverges from the subcool outdoor heat exchanger 32a, joins via the outdoor heat exchanger 32, and reaches the four-way valve 30. Refrigerant pipe until
Reference numeral 3 denotes a refrigerant pipe 81 from an intermediate portion of the refrigerant pipe 81 via an open / close valve 83a functioning as an electronic expansion valve when opened and the HIC 51.
It is a bypass pipe to the middle part of.

During cooling, the ports a and c of the four-way valve 30 are connected, and the ports b and d are connected. As a result, the compressed refrigerant gas is condensed in the outdoor heat exchanger 32 before passing through the ports a and c in reverse to the time of heating, passes through the expansion valve 52, evaporates in the indoor heat exchanger 31, and cools the room. Thereafter, the accumulator 3 passes through the ports b and d of the four-way valve 30.
Return to 5.

The subcool outdoor heat exchanger 32a
Functions as a condenser for further supercooling the refrigerant condensed and liquefied in the three outdoor heat exchangers 32 arranged in parallel. The HIC 51 on the refrigerant pipe is a heat exchanger for reducing pressure loss for improving COP (refrigerant coefficient of performance). That is, during the cooling operation, when the required load on the outside of the room is small and the high-pressure refrigerant is bypassed to the low-pressure side refrigerant pipe 80 through the bypass pipe 83, the on-off valve 83a is opened and a desired throttle opening degree is obtained. The HIC 51 heat-exchanges the low-pressure low-pressure refrigerant with the high-pressure high-temperature liquid refrigerant to further supercool (subcool) the high-pressure side, while functioning to assist the evaporation of the refrigerant on the low-pressure side.

The plate heat exchanger 34 is for heating the refrigerant introduced into the accumulator 35 with high-temperature engine cooling water along the piping. The plate heat exchanger 34 is provided with a bypass pipe 45,
COP is improved by reducing pressure loss during cooling.

The gas engine 1 is provided with a cooling water system 39, and cooling water is circulated by a cooling water pump 40. The cooling water sent by the cooling water pump 40 is supplied to the exhaust heat exchanger 14.
And is sent to the cooling jacket (not shown) of the engine by the second pump 41. A thermostat 42 is provided on the cooling water pipe on the outlet side from the engine to bypass the cooling water during a warm-up operation or the like. The cooling water system 39 is provided with a linear three-way valve 43 on the pipe on the engine outlet side, and a radiator 36 is provided in parallel with the outdoor heat exchanger 32 on the downstream side thereof. The radiator 36 is connected to a recovery tank 38. The linear three-way valve 43 allows the cooling water to flow to the radiator 36 side during cooling and dissipates heat by the fan 37 during cooling, flows to the plate heat exchanger 34 side through the branch pipe 44 during heating, and cools the high-temperature cooling water by heating the refrigerant. I do.
The amount of branching to the radiator 36 side and the plate heat exchanger 34 side can be adjusted and controlled.

FIG. 2 is a configuration diagram of a control system of the air conditioning system having the above configuration. System CP that controls the entire system
U70 includes a memory 72 storing a control map of the opening degree of the fuel valve, which will be described later, and is connected to an engine CPU 71 for driving and controlling the gas engine.

The system CPU 70 includes an indoor unit 61
It is connected to an operation unit provided on the side, and operation conditions such as operation mode switching and set temperature are input. Also, the system CPU
70 is a high-pressure saturation temperature sensor provided in the indoor unit, a high-pressure side refrigerant pressure sensor 77, a low-pressure side refrigerant pressure sensor 78 provided in the indoor unit and the outdoor unit 60, an outside air temperature sensor, a low-pressure saturation temperature sensor, and an accumulator liquid. Various detection data from the surface level sensor, the compressor temperature sensor 75, and other sensor groups are input, and based on these input data, the indoor unit fan and expansion valve of the indoor unit 61 and the four-way valve 30 and the linear three-way valve of the outdoor unit 60 43, drive control of the outdoor unit fan 37 and other valve groups.

The engine CPU 71 includes an exhaust pressure sensor 73,
Various operation state data is input from a group of sensors such as a camshaft pulser, a crankshaft sensor, a throttle opening sensor, a clutch signal, an exhaust temperature sensor, and a cooling water temperature sensor 76, and predetermined based on these operation state data. In accordance with the program, the ignition control circuit is driven to operate the ignition coil and spark the spark plug by arithmetic processing using a map or the like. Further, the throttle valve rotation actuator is driven to control the amount of intake air, and the fuel intake opening / closing valve operation actuator is driven to drive the fuel opening / closing valve 1.
0, and controls the fuel supply amount by driving the fuel control valve actuator.

FIG. 3 is a flowchart of the ignition timing control method according to the present invention. The contents of each step are as follows. S61: It is determined whether or not the heating operation is being performed.

S62: When not heating, the cooling operation is performed according to the cooling cycle.

S63: If heating is in progress, it is checked whether the outside air temperature is lower than a predetermined temperature T ° C. This predetermined temperature T ° C
Is the temperature at which frost may form on the outdoor heat exchanger.

S64: The temperature of the low pressure side refrigerant pipe connected to the refrigerant inlet side of the compressor is detected to check whether the low pressure saturation temperature is equal to or lower than a predetermined temperature T1 ° C. The predetermined temperature T1 ° C. is a temperature at which frost may form on the outdoor heat exchanger.

S65: If the temperature is lower than the temperature at which frost may occur in both steps S63 and S64, the control map of the fuel control valve is switched to the base map. This base map is a map of the fuel control valve opening that is set in advance according to the engine speed and the throttle opening, and is a map of the fuel control valve opening that is confirmed not to cause misfire. In the air-conditioning system control of the present embodiment, the base map for fuel control is gradually made lean while detecting misfire, leaned until a misfire limit or a desired operating state is obtained, and the base map is rewritten while learning this. Then, the feedback control of the fuel is performed according to the sequentially rewritten map. By using the lean rewrite map while detecting misfire in this way,
A stable lean burn operation is performed. In step S65 of the present embodiment, if the feedback fuel control by such learning control is being performed, this is canceled and the rewritten fuel control map is returned to the original base map. This prevents misfire when the ignition timing is retarded, as described later.

S66: It is checked whether it is within a preset retardable range in accordance with the engine speed and the throttle opening (see FIG. 5). This is to emphasize the combustion efficiency and output according to the operation range, or to check if ignition timing is not retarded during idle operation or the like.

S67: The amount of exhaust heat required to prevent frost is calculated based on the data of the outside air temperature and the low-pressure saturation temperature, and the retard amount for obtaining the amount of exhaust heat is calculated. The retard amount is a retard amount with respect to the base map of the ignition timing set in advance according to the engine speed and the throttle opening. In step S67, the calculated data of the retard amount is set to a preset maximum retard amount (allowable retard amount).
Check if:

S68: If the retard amount is equal to or less than the allowable amount, the ignition timing of the base map is retarded by the calculated retard amount.
As a result, the temperature of the exhaust gas of the engine increases, the amount of heat recovered in the exhaust gas heat exchanger increases, and the amount of heat transferred to the refrigerant in the refrigerant heat exchanger (plate heat exchanger 34) that heats the refrigerant increases. As a result, the refrigerant temperature rises and frost in the outdoor heat exchanger is prevented.

S69: The above steps S63, S64, S
If the conditions are not satisfied in 66 and S67, the ignition timing is controlled based on the basic base map without retarding the ignition timing.

FIG. 4 shows a map (base map) of the ignition timing according to the present invention. As shown, the ignition timing is set according to the map coordinates based on the throttle opening and the engine speed, that is, according to the operating range.
In this example, the ignition timing is set to the advanced side on the high-load side where the throttle opening is large at high engine speed and the throttle opening is set to secure the output, and the ignition timing is set to the retard side on the low-speed low load side and the exhaust heat recovery We are trying to increase. The optimum ignition timing is set for each operation region in consideration of the misfire limit, the output, the combustion efficiency, and the like, and corresponding to the most important operation condition required in the operation region.

With respect to such a base map, a retardable amount is set for each operation region, and when necessary, the ignition timing is retarded within the range of the retardable amount as described above (FIG. 3). Step S67).

FIG. 5 is a diagram showing a retardable area which is a criterion in step S66 in FIG. A circle indicates the retardable area. As shown, the retardable area is set only within a predetermined range according to the throttle opening (horizontal axis) and the engine speed (vertical axis). In other areas, the ignition is performed based on the ignition timing shown in the base map (FIG. 4), for example, with emphasis on output and drivability, and the ignition timing is not retarded.

FIG. 6 is a diagram showing the possible retardation amount of the ignition timing according to the operation range. As shown in the drawing, the retardable amount is set in accordance with an operation range corresponding to the engine speed and the throttle opening. In this example, the retardable amount is set to zero in the low-speed low-load region (that is, the ignition timing is controlled by the base map), and the retardable amount is increased as the rotational speed and the throttle opening increase to increase the medium rotational speed. The maximum value is set at the middle opening degree, and the retardable amount is gradually reduced as the rotational speed and the throttle opening increase, and the retardable amount is set to zero again at high rotation and high load.

FIG. 7 is a graph of the retardable amount in FIG. The horizontal axis represents the engine speed, and the vertical axis represents the retardation coefficient. Assuming that the advance angle value is T and the advance angle value obtained from the aforementioned map is T0, the advance angle value becomes T =
It is represented by T0 (1-Δt). Such a retardation coefficient Δ
By defining t for each predetermined throttle opening, for example, the retardable amount can be calculated corresponding to the entire range of the engine speed and the throttle opening.

FIG. 8 is a graph showing the relationship between the amount of retardation and the calorific value of exhaust gas. Graph a shows high-speed high-load operation,
Graph b shows a low-speed low-load operation. As shown,
The exhaust gas calorific value increases as the retard angle increases. In this case, the exhaust gas heat amount at the retard amount T is Q1 when the load is low and low load, and Q2 when the load is high and high load.
When the retard angle is increased from T by the retard amount TΔt, if the increase in exhaust gas heat amount is ΔQ1 at low temperature and low load and ΔQ2 is at high temperature and high load, ΔQ1 / Q1> ΔQ2
/ Q2, the rate of increase in the amount of heat is larger at low temperature and low load. In consideration of these characteristics, the retard amount and the retard coefficient Δt are determined for each operation region.

FIG. 9 is a graph showing the difference in misfire limit A / F when the ignition timing is made different. As shown in the figure, when the ignition timing is 15 degrees and 20 degrees BTDC and MBT (best ignition timing) at which high output is obtained, the A / F of the misfire limit changes to f1, f2, and f3, respectively. Therefore, for example, if the fuel control map supplies fuel at the A / F at point A in the figure when the ignition timing is operated at BTDC 20 degrees, the exhaust gas heat amount is increased as described above. For example, simply set the ignition timing to BTDC15
If the angle is retarded to a degree, a misfire will occur in this A / F.
Therefore, in the embodiment of the present invention, the map for fuel control is switched to the base map as described in step S65 of the flowchart of FIG. 3 so that misfire does not occur even if the ignition timing is retarded. To enrich the fuel. This makes it possible to retard the ignition timing in a state where stable combustion is maintained without causing misfire, to increase the amount of exhaust heat, and to prevent frost.

In the present invention, if the heating capacity is still insufficient even if the engine is driven at a predetermined high speed or more during the heating operation, that is, if the high-pressure saturation temperature of the refrigerant is detected and does not reach the predetermined value, As described above, the heating ability can be increased by retarding the ignition timing to increase the exhaust heat. In this case, the work amount of the combustion gas to the piston is reduced due to the retardation of the ignition timing, and the engine output is reduced somewhat.However, the exhaust gas temperature rises accordingly, and more exhaust heat is recovered by the exhaust gas heat exchanger. By using this for refrigerant heating, the heating capacity is increased. This makes it possible to increase the capacity as needed during the heating operation without changing the specification of the heating capacity in a hardware configuration.

[0050]

As described above, according to the present invention, when the outside air temperature is lower than the predetermined value during the heating operation and there is a possibility of frost, the ignition timing is retarded from the base map value and the exhaust gas temperature is reduced. As a result, the amount of heat recovered in the exhaust gas heat exchanger increases, and this heat is supplied to the refrigerant through the refrigerant heat exchanger, whereby the refrigerant temperature rises and frost in the outdoor heat exchanger is prevented. . Thereby, during normal operation, it is possible to set the ignition timing of the base map so as to obtain an optimum operation state with respect to the operation state such as combustion efficiency and output, and to retard the ignition timing when frost prevention is required. Further, it is possible to prevent frost while maintaining a desired operation state.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a gas engine driven heat pump air conditioning system to which the present invention is applied.

FIG. 2 is a configuration diagram of a control system of the air conditioning system of FIG.

FIG. 3 is a flowchart of an ignition timing control device according to the embodiment of the present invention.

FIG. 4 is a three-dimensional view of a map of ignition timing control according to the present invention.

FIG. 5 is an explanatory diagram showing a retardable region according to the present invention.

FIG. 6 is a view showing a retardable amount according to the present invention.

FIG. 7 is a graph showing a retardable amount in FIG. 6;

FIG. 8 is a graph showing a relationship between a retard amount and exhaust heat.

FIG. 9 is a graph showing a misfire limit A / F when the ignition timing is changed.

[Explanation of symbols]

1: gas engine, 2: refrigerant cycle, 3: air cleaner, 4: intake passage, 5: mixer, 6: throttle valve,
7: fuel supply pipe, 8: fuel control valve, 9: zero governor, 1
0: open / close valve, 11: oil separator, 12: exhaust pipe,
13: catalyst, 14: exhaust heat exchanger, 15: silencer,
16: drain separator, 17: exhaust outlet, 18: intake port, 19: neutralizer, 20: drain outlet, 21: oil pan, 22: oil tank, 23: oil supply pump, 2
4: clutch, 25: compressor, 26: flexible tube, 2
7: refrigerant inlet pipe, 28: refrigerant outlet pipe, 29: oil separator, 30: four-way valve, 31: indoor heat exchanger, 32: outdoor heat exchanger, 33: return pipe, 34: plate heat exchanger,
35: accumulator, 36: radiator, 37: fan, 38: recovery tank, 39: cooling water system, 40:
Cooling water pump, 41: second pump, 42: thermostat, 43: linear three-way valve, 44: branch pipe, 45: bypass pipe, 46: sub-accumulator, 47: throttle, 48,
49, 50: capillary tube, 51: HIC, 5
2: expansion valve, 60: outdoor unit, 61: indoor unit, 73: exhaust pressure sensor, 75: compressor temperature sensor, 76: cooling water temperature sensor, 77: high pressure side refrigerant pressure sensor, 78: low pressure side refrigerant pressure sensor, 80: Engine,
81: clutch, 82: fuel tank, 83: low pressure sensor, 84: open / close valve, 85: gas meter, 86: zero governor, 87: fuel control valve, 88: throttle driving actuator, 90, 91: pump, 92: radiator, 9
3: exhaust pipe, 94: exhaust heat exchanger, 95: gas fuel pipe, 96: intercooler, 97: high pressure sensor, 98:
Fuel distribution device

Continuation of front page (72) Inventor Hirofumi Yoshihara 2500 Shinkai, Iwata-shi, Shizuoka Yamaha Motor F-term (reference) 3G022 AA00 CA00 CA06 CA07 CA09 DA02 EA00 EA01 FA03 FA05 FA06 FA08 GA00 GA01 GA05 GA08 GA09 GA11

Claims (5)

[Claims] An exhaust gas heat exchanger and a refrigerant heat exchanger for heating a refrigerant by cooling water passing through the exhaust gas heat exchanger, wherein the base is based on a preset engine speed and throttle opening. In the method for controlling the ignition timing of a heat pump driving engine in which ignition timing is controlled by a map, the ignition timing is retarded from the ignition timing set in the base map when the outside air temperature is equal to or lower than a predetermined value during a heating operation. An ignition timing control method for a heat pump driving engine. 2. An exhaust gas heat exchanger, comprising: a refrigerant heat exchanger for heating a refrigerant by cooling water passing through the exhaust gas heat exchanger; and a base based on a preset engine speed and throttle opening. An ignition timing control method for a heat pump drive engine in which ignition timing is controlled by a map, wherein during a heating operation, when a low-pressure saturation temperature of the refrigerant is equal to or lower than a predetermined value, the ignition timing is set to be lower than the ignition timing set in the base map. A method for controlling the ignition timing of a heat pump driving engine, characterized in that the ignition timing is retarded. 3. The ignition of an engine for driving a heat pump according to claim 1, wherein the retardable amount of the ignition timing is set according to an engine speed and / or a throttle opening. Timing control method. 4. An exhaust gas heat exchanger, comprising: a refrigerant heat exchanger for heating a refrigerant by cooling water passing through the exhaust gas heat exchanger; a base based on a preset engine speed and throttle opening. An ignition timing control method for a heat pump driving engine in which ignition timing control is performed according to a map, wherein during a heating operation, when the engine speed is equal to or higher than a predetermined speed and the high-pressure saturation temperature of the refrigerant is equal to or lower than a predetermined value, the ignition timing is set to the base. An ignition timing control method for a heat pump driving engine, wherein the ignition timing is retarded from an ignition timing set on a map. 5. An exhaust gas heat exchanger, and a refrigerant heat exchanger for heating a refrigerant by cooling water passing through the exhaust gas heat exchanger, and ignition based on a preset engine speed and throttle opening. The ignition timing control and the fuel supply control are respectively performed by the timing control base map and the fuel control base map, and the fuel control base map is rewritten to the lean side by learning. During operation, if the outside air temperature or the low pressure saturation temperature is equal to or lower than a predetermined value, the ignition timing is retarded from the ignition timing set in the ignition timing base map, and returned to the first fuel control base map before rewriting. A method for controlling the ignition timing of a heat pump driving engine, comprising: