JPH03211346A - Control device for air conditioner - Google Patents

Abstract

PURPOSE:To improve an accumulated heating capability under a low surrounding air temperature by a method wherein a pulse output mode for determining an outdoor fan speed and the valve travel of an expansion valve is changed from those of a normal heating operation in response to an outdoor air temperature and an operating frequency. CONSTITUTION:An outdoor air temperature T1 sampled by an outdoor air temperature detection means 1 is compared with a predetermined outdoor set temperature value Ta by a comparisn means A5 so as to judge if the outdoor air temperature T1 is a low temperature as compared to the predetermined value Ta or not. Then, a frequency (f1) detected by an operating frequency detection means 3 of a compressor is compared with a predetermined frequency (fa) by a comparisn means B6 so as to discriminate the operating frequency. A calculation means 7 may receive a result of comparison from each of comparisn means A and B. In the event that there are a relation of the outdoor air temperature T1 < the predetermined temperature value Ta and another relation of the operating frequency (f1) > the predetermined frequency (fa), the outdoor fan speed is increased by one step and at the same time a pulse output mode is changed over to reduce the valve travel of an expansion valve. With such an arrangement, it is possible to restrict a frosting under a low temperature operation and to blow out hot air as well as to improve an accumulated capability.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention distinguishes between normal heating operation of an air conditioner and heating operation when the outside temperature is particularly low (hereinafter referred to as low-temperature operation). The present invention relates to a control device for an air conditioner that performs good control.

(Conventional technology) Conventional air conditioners have a pulse output mode that corresponds to the rotational speed of the outdoor fan and the operation (drive) frequency of the expansion valve during heating operation (from one defrosting operation to the next defrosting operation). The control content was always the same regardless of the outside temperature.

(Problem to be Solved by the Invention) As described above, in conventional control, since the outdoor fan speed setting during low-temperature operation is the same as during normal heating operation, the temperature of the refrigerant discharged by the compressor during operation ( The discharge temperature (discharge temperature) was also as low as during normal heating operation, and even if the load in the room increased as during low-temperature operation, the heating capacity of the air conditioner could not cope with the load. In other words, there was a tendency for the integrated capacity, which represents the performance of one cycle from the start of low-temperature operation to the end of defrosting operation, to be markedly reduced.

The present invention solves the above problems, and is a control device that performs load-based control when the outdoor temperature during heating operation is below a certain specified temperature and when the operating frequency is above the specified frequency. The purpose is to provide

(Means for Solving the Problems) In order to solve the above problems, the present invention provides an outdoor temperature detection means and a comparison means for comparing the detected temperature with a preset outdoor temperature setting value and outputting the result. A, a compressor operating frequency detection means and a comparison means B that compares the detected frequency with a preset specified frequency and outputs the result, and a comparator that calculates based on each output value of the comparison means A and B. a calculation means for outputting a required signal; an outdoor fan speed switching means for switching the outdoor fan speed according to the output signal of the calculation means; and a pulse output mode switching means for switching the opening degree of the expansion valve corresponding to the operating frequency of the compressor. It consists of

(Function) With the above configuration, when the outdoor temperature is below a certain specified temperature and the operating frequency is above the specified frequency, the outdoor fan speed is set higher than during normal heating operation, and the fan expands. Switch the pulse output mode to reduce the valve opening.

This makes it possible to suppress frost formation during low-temperature operation, blow out high-temperature air, and improve integration capacity.

(Example) Hereinafter, embodiments will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Reference numeral 1 indicates an outdoor temperature detection means, and 5 indicates a temperature that is determined by comparing the detected temperature with a preset outdoor temperature setting value 2. Comparison means A outputs the results, 3 is compressor operating frequency detection means, 6 is the detected frequency and preset specified frequency 4
Comparison means B = 7 is comparison means A which compares and outputs the result.

Calculating means 8 and 9 calculate based on each output value of B and output a required signal, and 8 and 9 respectively control the outdoor fan speed switching means for switching the outdoor fan speed and the operating frequency of the compressor based on the output signal of this calculating means 7. Pulse output mode switching means for switching the opening degree of the corresponding expansion valve; 10 is a drive means A for driving the outdoor fan 12 according to a control signal of the outdoor fan speed switching means 8; 11 is a pulse output mode switching means 9
This is a driving means B that drives the expansion valve 13 using a control signal.

Next, the operation of this embodiment will be explained with reference to the flowchart of FIG. When heating operation is instructed using the remote control or operation panel, the indoor/outdoor fan and compressor start operating.

Here, the outdoor temperature T1 sampled by the outdoor temperature detection means 1 and the preset outdoor temperature value Ta are compared by the comparison means A5, and it is determined whether the outdoor temperature T1 is lower than the temperature set value Ta. Determine (Step 1) 0
Next, the frequency/1 detected by the operating frequency detecting means 3 of the compressor and a preset specified frequency/a are compared by the comparing means B6 to determine the operating frequency (step 2).

The calculating means 7 receives the comparison results from the respective comparing means A and B, and determines that the outdoor temperature Tt<temperature setting value Ta and the operating frequency fr
>If the specified frequency fa, set the outdoor fan speed to V, -
The pulse output mode is increased by one step to +V2, and the pulse output mode is switched from P1 to P2 in the direction of narrowing the opening degree of the expansion valve. In other cases, vl.

It is controlled by P.

(Effects of the Invention) As explained above, according to the present invention, the pulse output mode that determines the speed of the outdoor fan and the opening degree of the expansion valve can be changed from the normal heating operation depending on the outdoor temperature and operating frequency. This makes it possible to improve the cumulative heating capacity, especially when the outside temperature is low.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
It is a flowchart of the same example. 1... Outdoor temperature detection means, 3... Compressor operating frequency detection means, 5... Comparison means A, 6...
Comparison means B, 7... Calculation means, 8... Outdoor fan speed switching means, 9... Pulse output mode switching means, 10 Drive means A, 1 Drive means B, 2 Outdoor fan, 3 Expansion valve .

Claims (1)

[Scope of Claims] An outdoor temperature detection means and a comparison means A that compares the detected temperature with a preset outdoor temperature setting value and outputs the result, and a compressor operating frequency detection means and its detected frequency. Comparing means B that compares the frequency with a preset specified frequency and outputs the result; a calculating means that calculates based on each output value of the comparing means A and B and outputs a required signal; It is comprised of an outdoor fan speed switching means that switches the outdoor fan speed according to an output signal, and a pulse output mode switching means that switches the opening degree of the expansion valve corresponding to the operating frequency of the compressor, and the outdoor fan is operated when the outdoor temperature is below the set temperature and when the compressor is operated. Control of an air conditioner characterized by increasing the outdoor fan speed setting compared to normal heating operation and switching the pulse output mode in the direction of reducing the opening degree of the expansion valve when the frequency is equal to or higher than a specified frequency. Device.