JP2003294337A - Engine-driven refrigerating cycle device and heating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine-driven refrigerating cycle device, and a heating system for improving heating capacity in a state of an outside air temperature being low, and the heating capacity being insufficient. <P>SOLUTION: An intake heater 11 is arranged in the middle of an intake air passage 1a of an engine. A control device 150 performs intake air heating for heating intake air of the engine 1 by the intake heater 11 when the outside air temperature is lower than a prescribed value, and recovers exhaust heat for heating a refrigerant by a refrigerant heater 7. This invention recovers a hated heat quantity as the exhaust heat by performing the intake air heating in operation at low temperature time, and uses the heat quantity as a heating heat quantity, and increases an exhaust heat quantity itself by activating sluggish engine combustion at low temperature time. Thus, the heating capacity can be efficiently improved by recovering the exhaust heat while performing the intake air heating in a state being low in the outside air temperature, and being insufficient in the heating capacity. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine-driven refrigeration cycle apparatus having a refrigeration cycle by circulating a refrigerant and an engine for driving a compressor of the refrigerant, for cooling or heating a fluid such as air or water. In particular, the present invention is suitable for application to a heating device or the like that heats air to heat a living room, particularly regarding improvement of heating capacity at low outside air temperature.

[0002]

2. Description of the Related Art In recent years, engine-driven refrigeration cycle devices using an engine to drive a compressor have become widespread, and in particular, many cooling / heating devices and hot water supply devices using a heat pump system are used in refrigeration cycles. In such a heat pump cycle, since heat is absorbed from the outside air during heating, the heat absorption efficiency decreases and the heating capacity decreases when the outside air temperature decreases (see the graph showing the relationship between the outside air temperature and the heating capacity in FIG. 2). For this reason, there is a problem in that the capacity becomes insufficient at low temperatures where heating capacity is required, which is a problem.

Incidentally, these engines are equipped with a cooling water circuit for cooling the heat generated, and the cooling water that has been heated after finishing the cooling work of the engine is radiatively cooled by a radiator and supplied again to the engine. , This is repeated to circulate. In the past, the heat of the engine cooling water, which had risen in temperature, was also exhausted from the heat of the exhaust gas and was never used. However, as a technique for solving the above problem, the reuse of such exhaust heat has recently been reviewed. In other words, it is to recover heat and use it effectively for heating and hot water heating.

As a system for recovering this kind of engine heat and utilizing it for assisting heating, the structure of a general engine-driven heat pump device is such that the water jacket of the engine or exhaust gas heats cooling water to raise the temperature. A refrigerant heater for supplying the heat of the cooling water to the refrigerant circuit is provided and incorporated in the refrigerant circuit. As a result, during heating in winter, the exhaust heat of the engine is recovered as a heat source, and the recovered heat is used to enhance the heating in the refrigerant circuit, and is exhausted during the summer season.

[0005]

However, even if the exhaust heat is recovered according to the above-mentioned prior art, the load itself for driving the compressor by the engine is reduced in extremely cold weather, so the exhaust heat generated from the engine is also reduced. Therefore, there is a problem that the heating amount is insufficient. The present invention has been made in view of the above conventional problems, and an object thereof is to provide an engine-driven refrigeration cycle device and a heating device capable of improving the heating capacity when the outside air temperature is low and the heating capacity is insufficient. To provide.

[0006]

In order to achieve the above object, the present invention employs the following technical means. Claim 1
In the invention described, the intake air heating means (11) is provided in the middle of the intake passage (1a) of the engine (1), and the control means (150) controls the outside air temperature (Tout) to a predetermined value (Tout).
If lower than 2), the intake air heating means (11) performs intake air heating for heating intake air of the engine (1), and the refrigerant heater (7) performs exhaust heat recovery for heating the refrigerant. .

An intake heater is an example of the intake heating means (11) provided in the intake passage (1a) of the engine (1), and FIG. 3 is a front view (a) of the intake heater 11 and FIG. It is a sectional side view. Conventionally, the intake heater 11 has been used as a starting aid for a diesel engine and as an exhaust emission countermeasure.

Specifically, as preheat, the heat generating plate 11a is energized to warm the intake air immediately before the engine is started, and the startability at low temperature is improved. Furthermore, as a after heat, the heating plate 11a
11b is energized to warm the intake air to stabilize the idle and reduce white smoke. However, conventionally, it is used only just before and immediately after the engine is started, and is not used during driving.

According to the present invention, by performing such intake air heating during operation at a low temperature, the heated heat amount is recovered as exhaust heat and utilized for heating heat amount, and at the same time, the engine combustion at a slow low temperature is activated. The focus is on increasing the amount of exhaust heat itself. By raising the intake air temperature of the engine, the mixture of air and fuel and the combustion reaction are activated,
The combustion temperature and the exhaust gas temperature rise and the heating degree of the cooling water rises. FIG. 4 is a graph for explaining the effect of this intake air heating, which is [exhaust heat amount A without intake air heating + intake air heating heat amount B <exhaust heat amount C with intake air heating].

As a result, as shown in the graph of FIG. 5 showing the difference in intake air heating effect with respect to the outside air temperature, the amount of exhaust heat can be improved especially at low outside air temperature. As a result, when the outside air temperature is low and the heating capacity is insufficient, exhaust heat recovery is performed while heating the intake air, so that the heating capacity can be efficiently improved.

According to the second aspect of the invention, the control means (15
0) indicates that the outside air temperature (Tout) is the first predetermined temperature (T1)
Exhaust heat recovery is performed when the temperature falls below the
t) is a second predetermined temperature (T1) lower than the first predetermined temperature (T1)
It is characterized in that the intake air heating and the exhaust heat recovery are performed when the temperature falls below 2).

FIG. 7 is a graph showing the effect of the intake air heating + exhaust heat recovery of the present invention. The outside air temperature at the point where the heating capacity (solid line curve) without the intake air heating and exhaust heat recovery intersects the required capacity is set to the first predetermined temperature (T1) and falls below this temperature (heating capacity falls below the required capacity. In this case, the heating capacity is raised to the broken line curve by first recovering the exhaust heat.

Next, the outside air temperature at the point where the heating capacity in the state where the exhaust heat is recovered intersects with the required capacity is set to the second predetermined temperature (T2), and the temperature is lower than this temperature (the heating capacity is lower than the required capacity). In this case, the heating capacity can be increased to the one-dot chain line curve by further adding intake air heating. In this way, by sequentially performing exhaust heat recovery and intake air heating when the outside air temperature is low and the heating capacity is insufficient, it is possible to efficiently improve the heating capacity. Incidentally, S7 to S9 in FIG. 7 correspond to the steps of the flowchart of FIG. 6 described later.

According to the invention of claim 3, the control means (15
0) is characterized by increasing the intake air heating amount as the outside air temperature (Tout) is lower in performing intake air heating. By increasing the heating amount as the outside air temperature is lower in this way, it becomes possible to efficiently compensate for the lowering of the heating capability at low temperatures and to secure the required capability. FIG. 8 is a graph showing the relationship between the outside air temperature and the intake air heating amount in the present invention, and the change of the intake air heating amount with respect to the outside air temperature is linear (K
It may be 1), stepwise (K2), or curvilinear (not shown) corresponding to a decrease in heating capacity.

According to a fourth aspect of the invention, the intake heater (11) is characterized by using an intake heater (11) which is an engine starting assisting device. As a result, the engine can be commonly used for assisting starting of the engine, measures for exhaust emission, and improvement of the heating capacity of the refrigeration cycle, and the cost can be suppressed.

According to a fifth aspect of the present invention, the engine-driven refrigeration cycle apparatus according to any of the first to fourth aspects is provided, and the condenser (5) is an indoor heat exchanger (5), and an evaporator is provided. (8) is an outdoor heat exchanger (8). This allows exhaust heat recovery while heating the intake air when the outside temperature is low and the heating capacity is insufficient.
The heater can efficiently improve the heating capacity.

In a sixth aspect of the invention, the control means (15
0) recovers exhaust heat when the room temperature (Tr) is lower than the first predetermined temperature (t1), and the room temperature (Tr) is the first
It is characterized in that the intake air heating and the exhaust heat recovery are performed when the temperature falls below a second predetermined temperature (t2) lower than the predetermined temperature (t1). This is the outside air temperature (Tou of the invention of claim 2
t) is replaced with the room temperature (Tr).

As in the case of the graph shown in FIG. 7, the heating capacity can be efficiently improved by sequentially performing exhaust heat recovery and intake air heating when the room temperature is low and heating capacity is required. By the way, the reference numerals in parentheses of the above-mentioned means are examples showing the correspondence with the concrete means described in the embodiments described later.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an overall configuration of an engine-driven heat pump type air conditioner (hereinafter, simply referred to as an air conditioner) 100 according to an embodiment of the present invention.

In this embodiment, a compressor 2 of a refrigerating cycle 110 is driven by circulating a refrigerant by a water-cooled engine 1 that uses kerosene, light oil, gasoline, etc. as a fuel to cool and heat the air in the living room. Air conditioning is performed. The air conditioner 100 is used as a stationary type or a vehicle-mounted type and can cool and heat the inside and the passenger compartment. However, in the present embodiment, it will be described as being applied to the stationary type.

First, the overall structure will be described.
A compressor 2, a four-way valve 4 that switches the flow path of the refrigerant, an indoor heat exchanger 5 that functions as an evaporator during cooling, and functions as a condenser during heating, an expansion valve 6 that is a pressure reducing means for the refrigerant, and an engine 1 Refrigerant heater 7 that heats the refrigerant with the cooling water warmed by the exhaust heat of, outdoor heat exchanger 8 that functions as a condenser during cooling and an evaporator during heating, and separates the refrigerant into gas and liquid to derive the gas refrigerant. The accumulators 9 are sequentially connected by a refrigerant circuit (solid arrow) 110 to form a basic refrigeration cycle.

Here, the compressor 2 is driven by a V-belt 3 which is interlocked with a crank pulley of the engine 1. still,
The indoor heat exchanger 5 and the outdoor heat exchanger 8 are provided with an indoor fan and an outdoor fan, which are driven by an electric motor, as blower means (not shown). Further, as the expansion valve 6,
As is well known, the temperature and pressure of the refrigerant at the outlet of the heat exchanger, which serves as the evaporator during operation, are detected by a temperature sensor and a pressure sensor, respectively, which are not shown, and the valve opening is set according to the detection signals from these sensors. A controlling electronic expansion valve is used.

On the other hand, the cooling water circuit (broken line) 1 of the engine 1
A circuit 20 passes from the engine 1 through the exhaust gas heat recovery machine 13, supplies hot water to the refrigerant heater 7 and then returns to the engine 1, and is circulated by the cooling water pump 14.

The exhaust gas heat recovery machine 13 is the engine 1
It is provided in the downstream of the exhaust manifold 1c and heats the cooling water by the exhaust gas to recover the exhaust heat of the exhaust gas. Further, the cooling water circuit 120 is also provided with a circuit for returning to the engine 1 through a radiator (not shown),
When exhaust heat is not recovered during cooling or the like, the cooling water is radiatively cooled through a radiator to prevent overheating.

In the intake / exhaust portion of the engine 1, 10 is an air cleaner in which dust is removed (cleaned).
Air passes from the intake passage 1a through an intake heater 11 (see FIG. 3) as an intake heating means, and the intake manifold 1
It is supplied to the engine 1 from b. Further, the exhaust gas after the fuel combustion flows from the exhaust manifold 1c through the exhaust gas heat recovery machine 13 through the exhaust passage 1d, is silenced by the muffler 15 in the middle, and is then discharged outside the machine.

In the air-conditioning apparatus 100 having such a configuration, the indoor heat exchanger 5 and the indoor fan among the respective constituent elements constitute the indoor unit 130 and are installed at appropriate places in the room, and the other elements have an internal engine. The outdoor unit 140 is configured as a device that is used by being fixedly installed at a suitable place outdoors.

The air conditioner 100 has a control device 150 composed of an electronic circuit or the like at an appropriate place in the outdoor unit 140. Then, to the control device 150, a set temperature Tset from an operation panel (not shown), an outside air temperature Tout, a cooling water temperature Tw, an exhaust temperature Tex, an indoor temperature Tr, etc. are input from a sensor group (not shown), and the engine 1 and the four-way valve are input. 4, by outputting control signals to the electronic expansion valve 6, the intake heater 11, the cooling water pump 14, etc., operation control of both of these machines 130, 140 is performed.

Next, the operation of this embodiment will be described based on the above configuration. During heating: When the heating switch of the control device 150 is activated, the four-way valve 4 is switched to the heating side (solid line), and the high-temperature gas refrigerant that has exited the compressor 2 passes through the four-way valve 4.
The indoor heat exchanger 5 condenses and heats.

After that, the pressure is reduced by the expansion valve 6, the heat of the engine 1 is recovered by the refrigerant heater 7 to be exchanged with the warm water to evaporate, and the outdoor heat exchanger 8 exchanges heat with the air (absorption of outside air). It is further evaporated, passes through the four-way valve 4 again, and returns from the accumulator 9 to the compressor 2. At this time, in the hot water circuit 120,
The hot water from the engine 1 is further heated by the exhaust gas heat recovery machine 13 by the exhaust gas, the refrigerant heater 9 heats the refrigerant, and then returns to the engine 1 again.

During cooling: When the cooling switch of the control device 150 is activated, the four-way valve 4 is switched to the cooling side (broken line), and the high-temperature gas refrigerant leaving the compressor 2 is discharged from the four-way valve 4 to the outdoor heat exchanger. 8, the heat is condensed and radiated, the refrigerant passes through the refrigerant heater 9, the pressure is reduced by the expansion valve 6, the heat is absorbed and evaporated by the indoor heat exchanger 5, and the air is cooled.

After that, the gas passes through the four-way valve 4 again, is separated into gas and liquid by the accumulator 10, and returns to the compressor 2 again. At this time, in the hot water circuit 120, the hot water from the engine 1 returns to the engine 1 again after being radiatively cooled through the radiator.

Next, the heating capacity improvement control of this embodiment will be described. FIG. 6 is a flowchart showing an example of a control program for improving heating capacity in the first embodiment of the present invention. First, in step S1, it is determined whether or not the refrigeration cycle is in a heated state. If it is in the heating state, it is considered that exhaust heat recovery or intake air heating may be necessary, and the process proceeds to the next step S2. Further, if it is not in the heating state, neither exhaust heat recovery nor intake air heating is required, so the routine proceeds to step S9 and is repeated in a state where neither exhaust heat recovery nor intake air heating is performed.

Next, in step S2, the outside air temperature Tou detected by the sensor group is used as information necessary for the subsequent determination.
t, cooling water temperature Tw, and exhaust temperature Tex are taken in.
Then, in step S3, the outside air temperature Tout is compared with the first predetermined temperature T1 to determine whether exhaust heat recovery is necessary. In the present embodiment, the first predetermined temperature T1 is set to 8 ° C. If it falls below 8 ° C., at least exhaust heat recovery is necessary and the process proceeds to the next step S4. Further, when the temperature is 8 ° C. or higher, exhaust heat recovery is not necessary, so the routine proceeds to step S9 and is repeated in a state where neither exhaust heat recovery nor intake air heating is performed.

In the next step S4, it is determined whether intake air heating is required at the cooling water temperature Tw. Here, the threshold value is set to 95 ° C. If the temperature falls below 95 ° C., intake air heating may be necessary, and the process proceeds to the next step S5.
If the temperature is 95 ° C. or higher, the exhaust heat can be recovered and the process proceeds to step S8 to recover the exhaust heat and not perform intake air heating.

In the next step S5, it is determined whether the exhaust temperature Tex is high enough to recover exhaust heat. Here, the threshold value is set to 300 ° C. If the temperature is lower than 300 ° C., intake air heating may be necessary, and the process proceeds to the next step S6. If the temperature is 300 ° C. or higher, the exhaust heat can be recovered and the process proceeds to step S8 to recover the exhaust heat and not perform intake air heating.

Next, at step S6, the outside air temperature Tout
Is compared with the second predetermined temperature T2 to determine whether intake air heating is required. In this embodiment, the second predetermined temperature T2 is set to 0.
The temperature is set to 0 ° C., and if the temperature is lower than 0 ° C., intake air heating is required and the process proceeds to the next step S7 to perform exhaust heat recovery and intake air heating. Also, if the temperature is 0 ° C or higher, intake air heating is not required,
In step S8, exhaust heat is recovered and intake air heating is not performed.

Next, the features of this embodiment will be described. The intake heater 11 is provided in the middle of the intake passage 1a of the engine 1, and when the outside air temperature Tout is lower than a predetermined value T2, the control device 150 heats the intake air of the engine 1 by the intake heater 11, and Exhaust heat recovery for heating the refrigerant is performed by the refrigerant heater 7.

In the present embodiment, by performing such intake air heating during operation at low temperature, the heated heat amount is recovered as exhaust heat and used as the heating heat amount, and the slow engine combustion at low temperature is performed. It is activated to increase the exhaust heat amount itself (see FIGS. 4 and 5). This can improve the amount of exhaust heat especially at low outside air temperature, so that when the outside air temperature is low and the heating capacity is insufficient, exhaust heat recovery can be performed efficiently while performing intake air heating. Can be improved.

Further, the control device 150 controls the outside air temperature Tou.
When the temperature t is lower than the first predetermined temperature T1, the exhaust heat is recovered and the outside air temperature Tout is lower than the first predetermined temperature T1.
When the temperature falls below the predetermined temperature T2, intake air heating and exhaust heat recovery are performed (see FIG. 7). In this way, by sequentially performing exhaust heat recovery and intake air heating when the outside air temperature is low and the heating capacity is insufficient, it is possible to efficiently improve the heating capacity.

Further, as the intake air heating means, an intake heater 11 which is an engine starting auxiliary device is used.
As a result, the engine can be commonly used for assisting starting of the engine, measures for exhaust emission, and improvement of the heating capacity of the refrigeration cycle, and the cost can be suppressed.

Further, such an engine-driven refrigeration cycle apparatus is provided, and the condenser is the indoor heat exchanger 5 and the evaporator is the outdoor heat exchanger 8. Thus, when the outside air temperature is low and the heating capacity is insufficient, the exhaust heat is recovered while the intake air is being heated, so that the heating apparatus can efficiently improve the heating capacity.

(Second Embodiment) FIG. 8 is a graph showing the relationship between the outside air temperature and the intake air heating amount in the second embodiment of the present invention. The difference from the first embodiment is that the control device 15
When the intake air heating is performed at 0, the intake air heating amount is increased as the outside air temperature Tout is lower. By increasing the heating amount as the outside air temperature is lower in this way, it becomes possible to efficiently compensate for the lowering of the heating capability at low temperatures and to secure the required capability.

(Third Embodiment) FIG. 9 is a flow chart showing an example of a control program for improving heating capacity in the third embodiment of the present invention. The flow chart of the first embodiment (FIG. 6) means that the outside air temperature Tout is the indoor temperature T
r, and the control device 150 controls the room temperature Tr.
Is lower than the first predetermined temperature t1 (18 ° C. in this embodiment), the exhaust heat is recovered, and the room temperature Tr is the first predetermined temperature t.
When the temperature falls below the second predetermined temperature t2 (10 ° C. in the present embodiment) lower than 1, intake air heating and exhaust heat recovery are performed.

Also in this case, similarly to the first embodiment, the exhaust heat recovery and the intake air heating are sequentially performed when the room temperature is low and the heating capacity is required, so that the heating capacity can be efficiently improved.

(Other Embodiments) The above embodiment is
Although the heat pump type air conditioner is driven by an engine, the present invention is not limited to this, and may be applied to a refrigerant compression type refrigeration cycle other than the heat pump type. Further, it may be applied to a hot water supply device or the like that heats brine (heat exchange medium) such as water or antifreeze liquid other than the air conditioner.

In the above-described embodiment, the electric heater is used as the intake air heating means, but the invention is not limited to this, and heat is exchanged with engine cooling water, engine exhaust gas, cycle refrigerant, etc. to superheat the engine intake air. May be. Also,
In the above-described embodiment, the electric power is supplied to the intake heater by the external power source, but the electric power obtained by providing the generator driven by the engine may be used.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the overall configuration of an engine-driven heat pump type air conditioner according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between outside air temperature and heating capacity.

3A and 3B are a front view and a sectional side view of an intake heater as an example of intake air heating means.

FIG. 4 is a graph illustrating the effect of intake air heating.

FIG. 5 is a graph showing a difference in intake air heating effect with respect to outside air temperature.

FIG. 6 is a flowchart showing an example of a control program for improving heating capacity in the first embodiment of the present invention.

FIG. 7 is a graph showing the effect of the intake air heating + exhaust heat recovery of the present invention.

FIG. 8 is a graph showing the relationship between the outside air temperature and the intake air heating amount in the second embodiment of the present invention.

FIG. 9 is a flowchart showing an example of a control program for improving heating capacity in the third embodiment of the present invention.

[Explanation of symbols]

1 engine 1a Intake passage 2 compressor 5 Indoor heat exchanger (condenser) 6 Expansion valve (pressure reducing means) 7 Refrigerant heater 8 Outdoor heat exchanger (evaporator) 11 Intake heater, intake air heating means 110 Refrigerant circuit (refrigeration cycle) 120 cooling water circuit 150 Control device (control means) T1, t1 first predetermined temperature T2, t2 Second predetermined temperature, predetermined value Tout outside temperature Tr room temperature

Claims (6)

[Claims] 1. A compressor (2) for compressing and discharging a refrigerant,
A condenser (5) for condensing the refrigerant, a pressure reducing means (6) for decompressing the refrigerant, and an evaporator (8) for evaporating the refrigerant.
A refrigeration cycle (110) formed by connecting the above in an annular shape, an engine (1) that drives the compressor (2), and the engine (1) in the middle of a cooling water circuit (120) of the engine (1). The state of the refrigerant heater (7) for heating the refrigerant with the cooling water warmed by the exhaust heat of the unit, the refrigeration cycle (110), the engine (1), and the cooling water circuit (120) is controlled. In an engine-driven refrigeration cycle apparatus including a control means (150), an intake air heating means (11) is provided in the middle of an intake passage (1a) of the engine (1), and the control means (150) controls the outside air. When the temperature (Tout) is lower than a predetermined value (T2), the intake air heating means (11)
The engine-driven refrigeration cycle apparatus is characterized in that the intake air heating for heating the intake air of the engine (1) is carried out, and the exhaust heat recovery for heating the refrigerant is carried out by the refrigerant heater (7). 2. The control means (150) performs the exhaust heat recovery when the outside air temperature (Tout) is lower than a first predetermined temperature (T1), and the outside air temperature (Tout) is the first outside temperature (Tout).
The engine-driven refrigeration cycle apparatus according to claim 1, wherein the intake air heating and the exhaust heat recovery are performed when the temperature falls below a second predetermined temperature (T2) lower than the predetermined temperature (T1). 3. The control unit (150) according to claim 1, wherein the intake air heating amount is increased as the outside air temperature (Tout) is lower in performing the intake air heating. Engine driven refrigeration cycle equipment. 4. The engine-driven refrigeration cycle apparatus according to claim 1, wherein an intake heater (11) which is an engine starting assisting device is used as the intake air heating means (11). 5. An engine-driven refrigeration cycle apparatus according to claim 1, wherein the condenser (5) is an indoor heat exchanger (5), and the evaporator (8).
The outdoor heat exchanger (8) is a heating device. 6. The control means (150) recovers the exhaust heat when the room temperature (Tr) is lower than a first predetermined temperature (t1), and the room temperature (Tr) is the first predetermined temperature (Tr). The heating device according to claim 5, wherein the intake air heating and the exhaust heat recovery are performed when the temperature falls below a second predetermined temperature (t2) lower than t1).