JP2998514B2 - Refrigerant heating and cooling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating / cooling machine having a refrigerant heater.

[0002]

2. Description of the Related Art Conventionally, this type of heating / cooling machine is configured as shown in FIG. That is, reference numeral 1 denotes a compressor, whose capacity can be varied by controlling the operating frequency by the controller 2.

The controller 2 controls a combustion amount of a burner 6 for heating the refrigerant heater 5 in accordance with a difference between a set air temperature and a suction air temperature of the indoor unit 4 detected by the suction thermistor 3. The compressor 1 is operated at an operation frequency preset according to the combustion amount of the burner 6.

[0004]

However, in the above-described conventional configuration, the compressor 1 is operated at an operation frequency set in advance according to the combustion amount of the burner 6, but the temperature of the intake air of the indoor unit 4 decreases. If the air volume setting is increased, the refrigerant pressure in the indoor heat exchanger 7 of the indoor unit 4 decreases, and the refrigerant evaporation pressure in the refrigerant heater 5 also decreases. Therefore, the suction pressure on the suction side 8 of the compressor 1 also decreases, and when the compressor 1 is kept operating at the same operating frequency, the amount of refrigerant circulated by the compressor 1 decreases.
Then, the circulation amount of the refrigerant necessary to balance the combustion amount of the burner 6 cannot be secured, and the refrigerant flowing in the refrigerant heater 5 is superheated near the outlet, and is generally used as a refrigerant for this type of heating / cooling machine. The temperature of the refrigerant becomes higher than the operating temperature range of the CFC 22 and deteriorates the refrigerant.
Damage.

When the temperature of the intake air of the indoor unit 4 rises or the air volume setting is reduced, the intake side 8 of the compressor 1
And the circulation amount of the refrigerant sent out by the compressor 1 increases. Then, more refrigerant than the circulation amount of the refrigerant necessary to balance with the combustion amount of the burner 6 flows through the refrigerant heater 5, and the refrigerant flowing in the refrigerant heater 5 cannot be completely evaporated and contains a large amount of liquid refrigerant. There is a problem that a liquid back is sent to the suction side 8 of the compressor 1 as it is and is sucked into the compressor 1 to cause liquid compression and damage the compressor 1.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to prevent overheating of the refrigerant and damage to the refrigerant heater and the compressor even when the indoor air temperature and the air volume change.

[0007]

According to the present invention, there is provided a heating / cooling apparatus comprising: a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing mechanism, and an outdoor heat exchanger connected to a refrigeration circuit. Comprising an on-off valve and a refrigerant heater in parallel with the pressure reducing mechanism and the outdoor heat exchanger, and a refrigerant temperature thermistor for detecting a refrigerant temperature in the refrigerant heater,
A controller is provided for increasing or decreasing a preset operating frequency of the compressor according to the amount of heat input to a burner that heats the refrigerant heater, based on the refrigerant evaporation temperature in the refrigerant heater detected by the refrigerant temperature thermistor. There is a configuration.

[0008]

According to the present invention, the operating frequency of the compressor is increased or decreased with respect to the fluctuation of the suction pressure of the compressor, and the amount of the refrigerant circulated from the compressor is transferred to the burner for heating the refrigerant heater. Can be balanced with the amount of heat input to the compressor, so there is no deterioration of the refrigerant or damage to the refrigerant heater due to overheating of the refrigerant heater, and there is no liquid back where the liquid refrigerant is sucked into the compressor. Can be prevented.

[0009]

An embodiment of the present invention will be described below with reference to FIG.

Reference numeral 11 denotes a compressor, which sequentially includes a four-way valve 12, an indoor heat exchanger 13, a pressure reducing mechanism 14, a first check valve 15, an outdoor heat exchanger 16, a four-way valve 12, and a second check valve 17. The refrigeration circuit is connected to the refrigeration circuit.
An on-off valve 18 and a refrigerant heater 19 are provided in parallel with the check valve 15 and the outdoor heat exchanger 16. A burner 20 heats the refrigerant heater 19 and evaporates the refrigerant in the refrigerant heater 19. 21 is a third check valve,
Reference numeral 22 denotes a throttle mechanism, which is connected so as to bypass the suction side 23 and the discharge side 24 of the compressor 11.

Reference numeral 27 denotes a controller which controls the combustion amount of the burner 20 in accordance with the temperature difference between a signal from a suction thermistor 26 for detecting the intake air temperature of the indoor unit 25 and the set temperature, and controls the combustion amount in accordance with the combustion amount. The compressor 11 is operated at a preset operation frequency. Further, the controller 27
Refrigerant heater 19 detected by refrigerant temperature thermistor 28
The operating frequency preset in accordance with the amount of combustion is increased or decreased according to the refrigerant evaporation temperature in the inside.

In the above configuration, the refrigerant during the heating operation is:
Compressor 11, four-way valve 12, indoor heat exchanger 13, on-off valve 1
8 and enters the refrigerant heater 19. Here, the refrigerant is burner 2
0 after being heated and evaporated by the suction side 23 of the compressor 11
And returns to the compressor 11 again.

Here, when the temperature difference between the suction air temperature of the indoor unit 25 detected by the suction thermistor 26 and the set temperature is large and the heating load is large, the controller 27 controls the burner 2.
The compressor 11 is operated at a preset operating frequency in accordance with the combustion amount while setting the combustion amount of 0 to be large.

On the other hand, the refrigerant pressure in the indoor heat exchanger 13 decreases due to a decrease in the temperature of the intake air of the indoor unit 25,
When the refrigerant evaporation pressure in the refrigerant heater 19 also decreases, the compressor 1
The suction pressure of the first suction side 23 also decreases, and the circulation amount of the refrigerant sent out by the compressor 11 decreases.

At this time, the controller 27 increases the operating frequency of the compressor 11 in accordance with the decrease in the refrigerant evaporation temperature detected by the refrigerant temperature thermistor 28 as the refrigerant pressure in the refrigerant heater 19 decreases, Control is performed so that the circulation amount of the refrigerant does not decrease, thereby preventing the refrigerant and the refrigerant heater 19 from being overheated.

Conversely, when the suction air temperature of the indoor unit 25 rises and the refrigerant evaporation pressure in the refrigerant heater 19 rises and the amount of circulating refrigerant increases, the controller 27 detects the refrigerant temperature thermistor 28. The operating frequency of the compressor 11 is reduced in accordance with the rise in the refrigerant evaporation temperature, and control is performed so that the circulation amount of the refrigerant does not increase, thereby preventing liquid back to the compressor 11.

On the other hand, even if the refrigerant evaporation pressure changes due to a change in the suction air temperature of the indoor unit 25 or the like, the balance between the circulation amount of the refrigerant and the combustion amount of the burner 20 may be lost.
The controller 27 controls the operating frequency of the compressor 11 according to the refrigerant evaporation temperature detected by the refrigerant temperature thermistor 28,
The combustion amount of the burner 20 and the circulation amount of the refrigerant are matched in a well-balanced manner, and the superheat of the refrigerant and the refrigerant heater 19 and the compressor 1
Prevent liquid back to 1.

[0018]

As described above, in the refrigerant heating / cooling machine of the present invention, the refrigerant evaporation temperature in the refrigerant heater is detected by the refrigerant temperature thermistor, and the temperature of the compressor is set in advance according to the input heat amount of the burner. Since the operating frequency is increased or decreased, the amount of heat input to the burner and the amount of circulating refrigerant are matched in a well-balanced manner even when the intake air temperature of the indoor unit changes, etc. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a refrigerant heating / cooling machine according to an embodiment of the present invention.

FIG. 2 is a system configuration diagram of a conventional refrigerant heating / cooling machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Compressor 12 Four-way valve 13 Indoor heat exchanger 14 Decompression mechanism 15 Outdoor heat exchanger 18 On-off valve 19 Refrigerant heater 20 Burner 27 Controller 28 Refrigerant temperature thermistor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-83556 (JP, A) JP-A-4-288457 (JP, A) Fully open 1987-6671 (JP, U) Really open 1984 195468 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 11/02 F25B 13/00

Claims (1)

(57) [Claims] 1. A refrigeration circuit is formed by connecting a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing mechanism, and an outdoor heat exchanger, and an open / close valve is provided in parallel with the pressure reducing mechanism and the outdoor heat exchanger. A refrigerant heater is provided, and a refrigerant temperature thermistor for detecting a refrigerant temperature in the refrigerant heater is provided, and the refrigerant heater is heated by a refrigerant evaporation temperature in the refrigerant heater detected by the refrigerant temperature thermistor. refrigerant heating air conditioner having a increasing <br/> Gensa causes controller operation frequency of the compressor set in advance in accordance with the input amount of heat to resolver over Na.