JPH03160282A - Engine driven air conditioner - Google Patents

Abstract

PURPOSE:To control a plurality of air conditioners having different horse powers based on the optimum rotary speed of an engine by deciding a rated rotary speed in conformity with an overall horse power of an indoor air conditioner and controlling an increase and decrease of a rotary speed of an engine in conformity with an average differential temperature of said indoor equipment. CONSTITUTION:A microcomputer 44 receives a signal which indicated low much the horse power of each indoor air conditioner is based on a signal 7 of a microcomputer 7 from each indoor equipment B. The microcomputer 44, when receiving a signal which indicates its in service from the indoor equipment B, tries to look for a total operation horse power the indoor equipment in service and decides a rated rotary speed and the lower limit rotary speed responding with this total power based on a rotary speed decision means 42. It also looks for the average differential temperature from the indoor equipment which is running. It proportionally controls the rotary speed responding with the average differential temperature based on a rotary speed control means 43 within the range of the rated rotary speed and the lower limit rotary speed, and it carries out proportional control as a rated rotary speed in the case when the average differential temperature exceeds 3 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION B) Industrial Application Field The present invention relates to an engine-driven air conditioner having an outdoor unit and a plurality of indoor units.

(Example) Conventional technology A conventional technology for an engine-driven air conditioner is described in Japanese Patent Publication No. 63-42183. It has a compressor driven by the engine, an outdoor unit housing an outdoor heat exchanger, and an indoor unit equipped with an indoor heat exchanger, and controls the rotation speed of the engine according to the difference between the indoor temperature and the set temperature. is configured to do so.

Recently, there are engine-driven air conditioners equipped with multiple indoor units. The speed is determined by the number of indoor units in operation, and there are some that perform proportional control of the engine speed. In addition, in a multi-type engine-driven air conditioning system equipped with six 2.5 horsepower indoor units, the engine speed is 1800 to 1500 rpm [17%
control range], 1500 to 1200 rpm [20%],
1200~900rpm [: 25%,
800 to 900 rpm [11%], the rotation speed Q control range is small, and comfortable air conditioning is poor. Furthermore, when two or one engine is operated, the engine speed cannot be lowered, and the engine speed is not controlled in accordance with the temperature difference between the set temperature and the room temperature.

(c) Problems to be Solved by the Invention In the same type of engine-driven air conditioner as described above, when indoor units with different operating horsepower are used, the total operating power of the indoor units being operated is Even if the number of indoor units is the same, there may be differences, so depending on the number of indoor units in operation,
Unable to determine engine rated speed. Also,
For example, if the indoor unit with larger horsepower is twice as powerful as the indoor unit with smaller horsepower, such as 2 horsepower and 4 horsepower,
It is easy to set the optimum engine speed, but if there are 6 indoor units and the operating horsepower of the indoor units is 2.5 horsepower, 3.0 horsepower,
In the case of different combinations of engines such as 4.0 horsepower, 5.0 horsepower, 6.0 horsepower, and 6.5 horsepower, it is very difficult to set the optimum engine speed.

The present invention provides an engine-driven air conditioner that can control a plurality of indoor units with different operating horsepower at an optimal engine speed.

(2) Means for Solving the Problems In order to solve the problems of the prior art described above, the present invention provides a single outdoor unit that includes an engine, a compressor driven by the engine, and an outdoor heat exchanger. , a plurality of indoor units equipped with an indoor heat exchanger, an indoor temperature detector, and a setting device for setting the indoor temperature, and the rotation speed of the engine is controlled according to the temperature difference between the set temperature and the indoor temperature. In the engine-driven air conditioner, each of the indoor units is provided with a setting means for setting the operating horsepower of the indoor unit, and further, the rotation speed of the engine is adjusted according to the total operating horsepower of the indoor units being operated. A rotation speed determining means for determining a rated rotation speed, and a rotation speed for increasing or decreasing the engine rotation speed within the rated rotation speed determined by the rotation speed determination means in accordance with the average temperature difference in the operating indoor units. For example, the control device is configured with a microcombuque, etc., and no matter which indoor units with different operating horsepower are being operated, or how many indoor units are being operated, the optimum control system can be set according to the total operating horsepower. The structure is such that the engine rotation speed can be controlled to a certain level.

(Thursday) Operation In the engine-driven air conditioner according to the present invention, the operating horsepower of the indoor units being operated is set by the setting means, and the rotation speed determining means is set based on the total operating horsepower of the indoor units being operated. A rated rotational speed of the engine is determined, and the rotational speed control means increases or decreases the rotational speed of the engine within this rated rotational speed according to the average temperature difference in the indoor unit being operated.

Therefore, even if the total operating horsepower changes, the rated engine speed is determined according to the changed total operating horsepower, and the engine speed is controlled within this rated speed, so the engine is not operated. Even if the total operating horsepower of the indoor units being operated increases or decreases, or even if indoor units with different operating horsepower are used, the engine rotation speed will change according to the total operating horsepower of the indoor units being operated. Optimally controlled.

The figure shows a circuit configuration diagram of an engine-driven air conditioner according to the present invention, in which (1) is a gas engine, (2) is a compressor driven by the driving force of this gas engine being transmitted through a flexible joint (3), (4) is an accumulator installed on the suction side of this compressor, (5) is a four-way valve that switches the refrigerant flow path depending on cooling or heating, (6> is an expansion valve [fi. pressure device],
(7) is an indoor heat exchanger, and <8) is an outdoor heat exchanger.

The compressor (2), four-way valve (5), outdoor heat exchanger (8)
, an expansion valve (6), an indoor heat exchanger (7), and other main components constitute a heat bomb circuit (9).

In addition, an outdoor unit (A>) is composed of main structural members such as the engine (1>, compressor (2), outdoor heat exchanger (8), expansion valve (6), four-way valve (5), etc. .

<10) is a temperature sensing part provided to control the opening degree of the expansion valve (6>), (1l) is a check valve, (12) is a receiver tank, (13) is a strainer, and (14) is a The solenoid valves (15) and (16) are refrigerant flow dividers.

17) is an oil separator provided in the refrigerant discharge flow path (l8); Solenoid valves (22) and (23) are provided in the pipeline.
The lengths of the pipe (19) are about 1 m, and the pipe (20) is about 0.5 m, and the length of the pipe (20) is short so that the refrigerant can easily pass through.

(24) is a solenoid valve installed in the middle of the pipe (25) connecting the accumulator (4) and the compressor (2); (26) is a bypass pipe installed to bypass this solenoid valve; ) is a pipe provided in parallel with this bypass pipe, and a solenoid valve (28) is provided in this pipe.

(29> is a temperature detector installed on the air suction side of the indoor heat exchanger (7>). (B) is the indoor heat exchanger (7)
, an indoor unit equipped with a temperature sensor (29), and this indoor unit is also equipped with an electric valve (32) and strainers (33) and (34). Furthermore, in the engine-driven air conditioner according to the present invention, five more indoor units (Bl) (B2) (B3) (
B4) (B5) Equipped with. These indoor units (B)
(Bl) to (B5) do not necessarily use units with the same operating horsepower, and since the operating horsepower of the outdoor unit (A) is 15 horsepower, the total operating horsepower of the indoor unit is also within this 15 horsepower. However, if it is acceptable to reduce the operating horsepower of each indoor unit a little, the indoor units may be combined until the total operating horsepower becomes 18 horsepower or less.

(35) is a cooling water circuit that cools the engine (1), and this cooling water circuit includes a heat exchanger (not shown) of the engine (1), an exhaust gas heat exchanger (36), and a cooling water pipe (37). )
, radiator tank 38), radiator cap (39),
Cooling water reserve tank (40), cooling water pressurized bomb (4)
It consists of 1).

FIG. 1 is an overall configuration diagram showing an engine-driven air conditioner according to the present invention. In this diagram, (42) indicates the rated rotation speed [maximum controlled rotation speed] shown in FIG. 3 of the indoor unit. Rated rotation speed determination means that is determined according to the total operating horsepower. For example, when the total operating horsepower is 2.5 horsepower to 5 horsepower, the minimum rotation speed is 800 rpm, and when the total operating horsepower is between 5 horsepower and 15 horsepower, the total operating horsepower is set. Increase the rotation speed to 200Orpm in proportion to
For 15 horsepower to 18 horsepower, the maximum rotation speed is 200 Orp.
m.

Further, the rotation speed determining means (42) also determines the lowest rotation speed at which the lower limit rotation speed at which the rotation speed of the engine (1) is controlled is lowered according to the average temperature difference, and this rotation speed is
80 when the total operating horsepower is 2.5 to 9.5 horsepower
0 rpm, and when it is 9.5 horsepower to 15 horsepower, the rotation speed is increased to 1200 rpm in proportion to the total operating horsepower,
When the horsepower is 15 to 18 horsepower, the engine speed is set to 1200 rpm.

Further, (43) is a rotational speed control means, which controls the rotational speed of the engine (1) within a range between the rated rotational speed and the lower limit rotational speed.

These rated rotation speed determining means (42) and rotation speed control means (43) are constituted by a microcomputer (44).

(45) is an operating horsepower setting means for setting the operating horsepower of the indoor unit (B), (46) is a temperature setting device, such as a wireless remote control, for setting the indoor temperature, and (47) is a temperature difference [
Communicate the signal of “difference between indoor temperature and set temperature”! 1! (4
In addition to this signal, this microcomputer also outputs signals indicating that this indoor unit is being operated and the magnitude of the operating horsepower of this indoor unit. It outputs the signal shown.

Note that this microcomputer (47) outputs a signal indicating the operating horsepower even if the indoor unit is not being operated.

In the engine-driven air conditioner according to the present invention configured as described above, a signal indicating the operating horsepower of each indoor unit is sent to the microcomputer (44) by a signal from the microcomputer from each indoor unit. When a signal indicating that the indoor unit is in operation is input, the microcomputer (4
4) determines the total operating horsepower of the indoor unit being operated, and determines the rated rotation speed and lower limit rotation speed according to this total operating horsepower. Also, calculate the average temperature difference from the temperature difference between the indoor units being operated.

Then, the rotation speed is proportionally controlled within the range of the rated rotation speed and the lower limit rotation speed according to the average temperature difference, and when the average temperature difference is 3° C. or more, the rotation speed is set as the rated rotation speed.

For example, the total operating horsepower of the indoor unit currently being operated is 12
．． In the case of 5 horsepower, the engine speed is the lower limit of rotation speed 103
It is controlled within the range from Orpm to the rated rotational speed of 1700 rpm. At this time, if the average temperature difference calculated from the temperature difference of each indoor unit is 2°C, the difference will be 1030rpffi to 170orpffi.
The rotation speed is controlled to 1477 rpm at two-thirds within the range of m.

In this way, when the rotation speed is controlled based on the average temperature difference, there are the following advantages.

If the proportional control is performed according to the minimum temperature difference between each indoor unit instead of control based on the average temperature difference, the engine rotation speed tends to decrease, and the indoor unit driver's power tends to be insufficient. Conversely, if the proportional control is performed according to the maximum temperature difference between each indoor unit, the engine speed tends to increase, and the operating force of the indoor unit tends to be excessive. There is a drawback that
This is because if the rotation speed is controlled based on this average temperature difference, the control will be able to prevent both of the above-mentioned drawbacks as much as possible.

In addition, in this engine-driven air conditioner, as shown in FIG. 3, when the rotation speed control range is less than 20% [6.
If the horsepower is 5 horsepower or less, connect the suction side pipe (25) of the compressor (2).
) control of the increase/decrease in refrigerant flow rate by controlling the solenoid valves (24) (2B) is utilized for control based on the average temperature difference.

To explain an example, when the total operating horsepower of the indoor unit is 5 horsepower, the rotation speed of the engine (1) is fixedly controlled at 800 rpm, and when the average temperature difference is 3°C or more, the solenoid valve (24) and (28) are both closed, and when the average temperature difference is 2°C or more and less than 3°C, the solenoid valve (24) is opened, and the solenoid valve (28) is closed, and the average temperature difference is 1°C or more and 2°C. When the temperature difference is less than 1°C or when the average temperature difference is 0'C or more and less than 1°C, the solenoid valve (
24) (28) is controlled to open.

It's in order.

In addition, in this engine-driven air conditioner, when the total operating horsepower of the outdoor unit is 10 horsepower or more, the engine (1> rotation speed
It is set to have a control width of 0%, but this was determined based on the condition that the blowing temperature from the indoor unit does not fall below 40°C [because if the temperature drops below this temperature, the air will feel cold]. be.

(G) Effects of the Invention As explained above, according to the present invention, the rated rotation speed is determined according to the total operating horsepower of the indoor unit, and the engine rotation speed is controlled within this rated rotation speed. , even if indoor units with different operating horsepower are installed, the engine rotation speed is controlled according to the total operating horsepower no matter how many indoor units are operated, so the engine rotation speed can be controlled optimally. It is possible to provide a driven air conditioner.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an engine-driven air conditioner according to the present invention, FIG. 2 is a circuit diagram of the engine-driven air conditioner according to the present invention, and FIG. 3 is an engine-driven air conditioner according to the present invention. This is a line section showing the relationship between the total operating horsepower of the indoor unit and the engine rotation speed. (1)...Engine, (2)...Compressor, (7
)...Indoor heat exchanger, (8)...Outdoor heat exchanger,
(29)...Indoor temperature detector, (42)...Rated rotation speed determining means, (43>...Rotation speed control means,
(45)...Operating horsepower setting means, (46>...
Indoor temperature setting device, (A)...Outdoor unit, (B) (Bl
) (B2) (B3) (B4) (B5)...Indoor unit.

Claims (1)

[Claims] (1) An outdoor unit equipped with an engine, a compressor driven by the engine, and an outdoor heat exchanger, and multiple indoor units equipped with an indoor heat exchanger, an indoor temperature detector, and a setting device for setting the indoor temperature. In the engine-driven air conditioner, the engine speed is controlled according to the temperature difference between the set temperature and the indoor temperature, a setting means that can set the operating horsepower of the indoor unit to each of the indoor units; A rotation speed determining means for determining the rated rotation speed of the engine according to the total operating horsepower of the indoor unit being operated; and a rotational speed control device that controls the rotational speed of the engine to increase or decrease within the rated rotational speed determined by the rotational speed determining means according to the average temperature difference in the engine. type air conditioner.