JPH10196350A - Heater control device for exhaust gas purifying catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater control device for an exhaust gas purifying catalyst which is formed such that a catalyst is excellently functioned even right after the starting of a gas engine and a consumption power is reduced. SOLUTION: A control device for the heater 29 of an exhaust gas purifying catalyst 27 comprises a temperature sensor 21 (thermo) to detect temperature in a room being a temperature regulation object for an air-conditioner 17, and a controller 41 to predict running operation of a compressor 11 in a very near future and control operation of a heater. The starting of a gas engine 23 is previously predicted, energization of a catalyst heater is early started, from a first point of time when a gas engine is started to operate, a catalyst to sufficiently function, and complete purification of exhaust gas is expected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an air conditioner system having a compressor driven by an engine.
The present invention relates to an apparatus for controlling a heater for heating a catalyst for purifying exhaust gas of an engine. In particular, the present invention relates to a heater control device for an exhaust gas purifying catalyst in which a catalyst functions well immediately after the start of an engine and is improved to reduce power consumption.

[0002]

2. Description of the Related Art The prior art will be described using a gas engine driven compressor during a heat cycle as an example. FIG.
FIG. 1 is a system diagram showing a configuration of a heat cycle including a gas engine driven compressor. This heat cycle 100
Comprises a compressor 101, a condenser 113, an expansion valve 115, an evaporator 117, and a pipe connecting them.

[0003] A compressor 101 is driven by a gas engine 102 (motor). The gas engine 102 is a reciprocating engine (or turbine) that receives supply of city gas from a gas supply pipe 103 and uses the gas as fuel.
The speed (output) of the gas engine 102 is controlled by a gas flow control valve 104 of a gas supply pipe 103. The compressor 101 sucks the refrigerant from the suction port 101a, compresses the refrigerant, and discharges the refrigerant from the discharge port 101b.

[0004] The compressed refrigerant is cooled and condensed in the condenser 113 by receiving external air from the fan 114. The condensed refrigerant is sent to an indoor air conditioner or the like, and expands in the expansion valve 115 and the evaporator 117. At that time, a large amount of heat is taken to cool the room. The refrigerant returns from the evaporator 117 to the compressor 101 again, and thereafter circulates similarly.

The exhaust gas of a gas engine contains formaldehyde and the like and has a strong odor. For this deodorization, Pt or R
It is effective to treat the exhaust gas with a catalyst such as h. The temperature required for exhaust treatment with these catalysts is 200 ° C
That is all. However, the exhaust temperature of a normal gas engine is about 60 ° C., which is considerably lower than the required temperature.
A deodorizing catalyst active at a temperature as low as 60 ° C. has not been developed so far. On the other hand, there is a method in which the exhaust gas is heated by a heater, but this is not advantageous because the cost of the apparatus is increased.

[0006] There are usually two types of control of such a catalyst heater. ON / OFF of heater energization is controlled by the gas temperature of the catalyst or its part. Power is supplied when exhaust gas is flowing (when the gas engine is running) and when exhaust gas is not flowing (when the gas engine is stopped)
Is not energized.

[0007]

However, the control of these conventional catalyst heaters has the following problems. In the case of the control based on the catalyst temperature, the power is supplied even when the exhaust gas is not flowing, and the power consumption may be increased more than necessary. In the type of switching between energization and non-energization by the flow of exhaust gas, the temperature is low immediately after the gas starts to flow (immediately after the start of the gas engine operation), and the catalytic reaction is insufficient.

FIG. 2 is a time chart of a control system for turning on / off the catalyst heater in accordance with the presence or absence of the exhaust gas flow. Exhaust gas ON-OF from top to bottom
F, ON-OFF of heater, and catalyst temperature.

At the time point A, the heater energization is turned on together with turning on the exhaust gas (starting the flow). Then, the catalyst temperature starts to increase with the heater ON. However, the catalyst temperature falls within the active temperature range of the catalyst temperature (ΔT in the figure) at the time point B after a lapse of time t. Therefore, during this time t, the catalyst does not function sufficiently,
Exhaust gas is not sufficiently purified. Thereafter, at the time point C, the heater energization is turned off together with turning off the exhaust gas (stopping the flow). And the catalyst temperature is heater OF
Although the temperature starts to decrease together with F, the catalyst temperature is unnecessarily maintained in the active temperature range (ΔT in the figure) until the point D when the time t ′ has elapsed since the heater was turned off. Therefore, the heater power is wasted.

It is an object of the present invention to provide a heater control device for an exhaust gas purifying catalyst which does not have the above-mentioned problems and which can function satisfactorily immediately after starting a gas engine and can reduce power consumption. And

[0011]

In order to solve the above-mentioned problems, a heater control device for an exhaust gas purifying catalyst according to the present invention heats a catalyst for purifying exhaust gas of an engine in an air conditioner system having a compressor driven by an engine. A temperature sensor (thermo) for detecting a temperature of a room to be adjusted for temperature of the air conditioner; and a predicting operation of the compressor in the near future from the room temperature. And a controller for controlling the operation of the heater.

That is, the start of the engine is predicted in advance, the energization of the catalyst heater is started early, and the catalyst is fully operated from the first time when the engine starts to operate, so that exhaust gas purification is completed. And In addition, the stop of the engine is predicted in advance, and the energization of the catalyst heater is stopped earlier to save power consumption.

[0013]

In the present invention, it is preferable that a temperature sensor for detecting the temperature of the catalyst is further provided, and the controller controls the operation of the heater in consideration of the exhaust gas temperature. When the catalyst temperature is sufficiently high, the heater can be turned off to save power consumption.

Hereinafter, a specific description will be given with reference to the drawings. FIG. 1A is an overall system diagram of a gas heat pump air conditioner having a heater control device for an exhaust gas purifying catalyst according to one embodiment of the present invention. FIG. 1B is a time chart showing the operating state of the exhaust gas purifying catalyst of the air conditioner.

The gas heat pump air conditioner 1 has a compressor 11 driven by a gas engine 23. The compressor 11 compresses a heat medium (refrigerant). The compressed refrigerant is condensed in the condenser 13 and expanded in the expansion valve 15. The expanded refrigerant evaporates in the evaporator 17, and at this time, the heat of the room 3 is taken. The expanded refrigerant is compressed again by the compressor 11.

The exhaust gas of the gas engine 23 is supplied to the exhaust pipe 2
5, the exhaust gas enters the exhaust gas purifying catalyst 27, and is further discharged from the exhaust gas pipe 31. The catalyst 27 has a catalyst heater 2
9 is provided to heat the catalyst 27 to a suitable operating temperature. A temperature sensor 33 is provided in the exhaust gas pipe 31 on the exit side of the catalyst 29 to detect the temperature of the exhaust gas. In addition, this temperature sensor 33 is directly attached to the catalyst section,
The catalyst temperature may be detected.

In the room 3, an indoor temperature sensor 21 (thermo) for controlling an air conditioner is installed. The indoor temperature sensor 21 detects the indoor temperature and controls the operation of the gas engine 23. Heater controller 41
Are the indoor temperature sensor 21 and the exhaust gas temperature sensor 33
Of the catalyst heater 29 based on the temperature signal from
Control N-OFF.

The control operation of the heater controller 41 will be described with reference to FIG. The ON-OFF of the flow of exhaust gas (O
N-OFF) is shown. In the middle part of FIG.
ON-OFF of heater energization is shown. here,
The heater is energized at the time point A earlier than the exhaust gas ON. This is because the temperature of the room 3 is always
If monitoring is performed at 1 (thermo) to predict the start of operation of the gas engine 23 (start of operation of the compressor 11), and if the catalyst temperature is low at this time, the heater energization is started in advance.

As a result, the catalyst temperature rises, and at timing B when the exhaust gas starts to flow, the catalyst temperature falls within the active temperature range.

Thereafter, during operation of the gas engine, the heater energization is turned ON / OFF based on the catalyst temperature. Therefore, at time C, when the catalyst temperature reaches the upper limit of the activation temperature, the heater energization is turned off. Thereafter, at time D, when the catalyst temperature reaches the lower limit of the activation temperature, the heater energization is turned ON.

During this time, the room temperature is constantly monitored, and E
When the thermo-OFF is predicted at the time of
Before reaching the point F at which the operation stops, the energization of the heater is stopped. In this way, the operation state of the catalyst heater is turned on by predicting the operating state of the gas engine in the near future from the room temperature.
It is turned off to ensure exhaust gas purification.

[0022]

As is apparent from the above description, according to the present invention, the catalyst can function well immediately after the start of the gas engine and the power consumption can be reduced. Further, in addition to controlling the temperature of the catalyst, the heater is turned ON / OFF by predicting the stop of the gas opening, so that the power consumption can be reduced.

[Brief description of the drawings]

FIG. 1A is an overall system diagram of a gas heat pump air conditioner having a heater control device for an exhaust gas purifying catalyst according to one embodiment of the present invention. (B) is a time chart showing the operating state of the exhaust gas purifying catalyst of the air conditioner.

FIG. 2 shows that the catalyst heater is turned on according to the presence or absence of the exhaust gas flow.
It is a time chart of the control method of N-OFF.

FIG. 3 is a system diagram showing a configuration of a heat cycle including a gas engine driven compressor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Gas heat pump air conditioner 3 Room 11 Compressor 13 Condenser 15 Expansion valve 17 Evaporator 21 Thermo 23 Gas engine 25 Exhaust gas pipe 27 Exhaust gas purification catalyst 29 Heater 31 Exhaust gas pipe 33 Exhaust gas temperature sensor 41 Controller 43 Power supply

Claims (2)

[Claims] 1. An air conditioner system having a compressor driven by an engine, wherein the device controls a heater for heating a catalyst for purifying exhaust gas of the engine;
A temperature sensor (thermo) for detecting the temperature of a room to be temperature-controlled for the air conditioner; and a controller for predicting the operation of the compressor in the near future from the room temperature and controlling the operation of the heater. A heater control device for an exhaust gas purifying catalyst, comprising: 2. The exhaust gas according to claim 1, further comprising a temperature sensor for detecting a temperature of the catalyst, wherein the controller controls an operation of the heater in consideration of the temperature of the catalyst. Heater control device for purification catalyst.