JP3327685B2 - Refrigerant heating / 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 refrigerant heating type heating / cooling machine which detects an inlet temperature of a refrigerant heater and varies a specific combustion output in accordance with the detected temperature.

[0002]

2. Description of the Related Art Conventionally, during a cooling operation, a refrigerant heating type warming / cooling machine flows high-temperature, high-pressure refrigerant from a compressor to an outdoor heat exchanger through a four-way valve to condense, and decompresses the pressure by a decompression device. In the heating operation, the four-way valve is switched to allow the high-temperature refrigerant from the compressor to flow to the indoor heat exchanger and condense, and the condensed refrigerant to be discharged to the outdoor heat exchanger. The condensed refrigerant is allowed to flow to the refrigerant heater without flowing to the heat exchanger, and the condensed refrigerant is heated and evaporated by the burner provided in the refrigerant heater and returned to the compressor.

The outlet temperature of this refrigerant heater is detected by an outlet refrigerant temperature sensor, and the operation output is determined by the refrigerant outlet temperature sensor.

[0004] That is, in the combustion in the refrigerant heater, the supply amount of gas, oil and the like supplied to the burner is determined so that the refrigerant in the refrigerant heater can obtain the amount of heat of evaporation corresponding to the air conditioning load on the indoor side. The supply amount (combustion output) is set by the operation output (S code), and the control operation is performed in a proportional relationship between the operation output and the combustion output within the normal operation range.

In the control operation in the normal operation range, the minimum value of the operation output when the air-conditioning load is low is that when the refrigerant in the refrigerant heater evaporates due to the combustion of the burner, the latent heat of evaporation causes condensation on the refrigerant heater. And the maximum value of the operation output when the air-conditioning load is high is set so that the suction refrigerant temperature of the compressor does not become overheated.

In the control operation, when the overload rises, for example, when the air conditioning load is large such as the rising operation of the heating operation, the operation output is set to the maximum value, and when the load decreases, the operation output is gradually shifted down. When the value becomes a value, the operation output is turned off.

[0007]

However, as described above, the normal operation range is such that the combustion output is exchanged with the circulating refrigerant in the refrigerant heater, and the refrigerant output is condensed to the liquid back of the refrigerant, condensation in the combustion chamber, or piping. Is set in a range from the minimum value to the maximum output of the level at which the heat transfer can be performed evenly.

However, when the above-mentioned operation output is set in the above-mentioned normal operation range, there are the following problems.

(1) Since a compressor using a standard type compressor reaches the OFF point at a stretch, ON / OFF is repeated and it takes time to stabilize the cycle.

(2) In the transitional period of the cycle (low load, rise of overload), it exceeds the range of use and is frequently turned on.
/ OFF is easy to repeat.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a refrigerant heating / cooling machine capable of increasing the combustion output of a refrigerant heater at an early startup at the start of operation and at an overload. And

[0012]

In order to achieve the above object, the present invention according to claim 1 provides a cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are sequentially connected. During the heating operation, a refrigerant heater that heats the condensed refrigerant of the indoor heat exchanger and returns it to the compressor is connected to a circuit in which the four-way valve and the indoor heat exchanger are sequentially connected to the compressor, and an outlet of the refrigerant heater. In a refrigerant heating / cooling machine configured to control a refrigerant heater with a normal combustion output according to a refrigerant temperature, a refrigerant inlet temperature of the refrigerant heater is detected between the indoor heat exchanger and the refrigerant heater. A condensation temperature sensor, a normal combustion output corresponding to the refrigerant temperature of the refrigerant heater is set, and a specific combustion output lower than the minimum value of the normal combustion output is set, and the detected value of the condensation temperature sensor is set. Input and detection of its condensation temperature sensor In those having a control means for switching from a normal combustion output to a particular combustion output.

According to a second aspect of the present invention, the control means switches to a specific combustion output when the temperature of the refrigerant inlet falls below a set lower limit at the time of low-temperature starting of heating.

According to a third aspect of the present invention, the control means switches to a specific combustion output when the refrigerant inlet temperature exceeds a set upper limit value during an overload operation of heating.

According to a fourth aspect of the present invention, the control means controls the combustion of the refrigerant heater with a specific combustion output during a delay time of the initial control at the time of starting heating.

[0016]

According to the above construction, a specific output that is lower than the normal combustion output range is set, and when the inlet refrigerant temperature enters the transitional temperature range, the combustion is not stopped and the specific combustion output is reduced as in the conventional case. By performing the operation, the cycle at the time of startup can be quickly stabilized, and the operation range at the time of overload can be expanded.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a pressure reducing device 4 such as a capillary tube,
A cycle 6 is formed by connecting the indoor heat exchangers 5 in order, and in the cycle 6, refrigerant heating that returns condensed refrigerant from the indoor heat exchanger 5 to the compressor 1 by bypassing the outdoor heat exchanger 3 during heating. Line 7 is connected and the line 7
Is connected to the refrigerant heater 8.

During the cooling operation, the refrigerant flows from the compressor 1 to the four-way valve 2, the outdoor heat exchanger 3,
The flow returns to the compressor 1 via the four-way valve 2 via the decompression device 4 and the indoor heat exchanger 5, and during the heating operation, the compressor 1 is switched by switching the four-way valve 2 as shown by a dotted arrow in the figure. Then, the flow returns to the compressor 1 via the indoor heat exchanger 5 via the four-way valve 2 and the refrigerant heater 8 of the refrigerant heating line 7.

An accumulator 9 is connected between the four-way valve 2 and the suction side of the compressor 1. Further, between the discharge side and the suction side of the compressor 1, the amount of refrigerant circulating to the cycle 6 during heating operation is adjusted. A bypass circuit 12 consisting of a two-way valve 10 and a capillary tube 11 is connected and the outdoor heat exchanger 3
A refrigerant return line 14 having a recovery check valve 13 for returning the refrigerant accumulated in the compressor 1 to the compressor 1 is connected to the outdoor heat exchanger 3.

The decompression device 4 includes an indoor heat exchanger 5 during heating.
A heating check valve 15 for flowing condensed refrigerant from the refrigerant to the refrigerant heating line 7 is connected, and in the cycle on the side of the outdoor heat exchanger 3, for cooling, the condensed refrigerant is prevented from flowing to the outdoor heat exchanger 3. The check valve 16 is connected.

The refrigerant heating line 7 is connected to the parallel circuit 19 of the save valve 17 and the capillary tube 18 from the upstream side, and connected to the refrigerant heater 8 at the downstream side, and between the parallel circuit 19 and the refrigerant heater 8. A main circuit valve 20 is connected to open the refrigerant during the heating operation, allow the refrigerant to flow, close during the cooling operation, and return the refrigerant accumulated in the refrigerant heater 8 to the compressor 1 via the refrigerant heating line 7.

On the discharge side of the compressor 1, a refrigerant introduction line 21 for flowing low-temperature refrigerant to the refrigerant heater 8 directly through the main circuit valve 20 at the time of start-up is connected, and the line 21 is connected to an on-off valve 22 and a capillary. The tube 23 is connected.

The refrigerant heater 8 has a burner 24 for burning gas and the like, and a proportional control valve 2
6. The solenoid valve 27 is connected.

A condensing temperature sensor 28 for detecting the condensed refrigerant temperature (TEI) from the indoor heat exchanger 5 during the heating operation is mounted on the upstream side of the refrigerant heating line 7. An outlet refrigerant temperature sensor 29 is attached.

The detected temperatures of the outlet refrigerant temperature sensor 29 and the condensing temperature sensor 28 are input to control means (not shown), and the control means outputs an operation output to the proportional control valve 26 so that the refrigerant heater 8 The combustion of the burner 24 is controlled.

In the figure, reference numeral 30 denotes a check valve connected to a pipe between the four-way valve 2 and the suction side line of the compressor 1.

In the above, the control means outputs an operation output to the control valve 26 in accordance with the temperature detected by the outlet refrigerant temperature sensor 29 so that the combustion amount becomes a combustion amount commensurate with the air conditioning load during heating. The opening of the proportional control valve 26 is controlled in accordance with the operation output, and the amount of combustion in the burner 24 is adjusted.

The amount of combustion by the control means is controlled so that the operation output and the combustion output are in a proportional relationship as shown in FIG. 2, and within the normal combustion output range of the dotted area shown in FIG. A range of the operation output is set, and if the operation output range is equal to or less than the minimum value (DS), the combustion chamber in the refrigerant heater 8 is condensed. Therefore, conventionally, the proportional control valve 26 (or the solenoid valve 27) is used.
Is controlled to be OFF, and the maximum value (DM)
Is set so that the compressor 1 side is not overheated, and when exceeding the maximum value (DM), the operation output is gradually shifted down and then turned off.

In the present invention, the control means sets a specific combustion output which is smaller in output than the normal operation output range and which is indicated by oblique lines in the figure, and when the temperature of the condensing temperature sensor 28 is in a transitional period, this control is set. The combustion amount of the burner 24 is controlled by the specific combustion output.

That is, as shown in FIG. 3, of the temperatures (TEI) detected by the condensing temperature sensor 28, the temperatures fall within a range between a lower limit set temperature (TEI (1)) and an upper limit set temperature (TEI (2)). In some cases, control is performed within the normal combustion output range. When the temperature falls below the lower limit set temperature (TEI (1)), control is performed at a specific combustion output. When the temperature exceeds the upper limit set temperature (TEI (2)), specific combustion is performed. Control by output.

By controlling in this way, at the start of operation,
In particular, since the cycle at the start of low temperature is stabilized early and the output can be switched to the specific combustion output by the condensing temperature (TEI) at the time of overload, the cycle is maintained without stopping the compressor 1 without operating the compressor 1. Can be stabilized.

Further, at the time of the heating start operation, the control means performs heating start control, that is, first, the compressor 1 is started, and after a certain delay time, the burner 24 of the refrigerant heater 8 is started.
When the refrigerant temperature is low, the indoor heat exchanger 5 is controlled during the delay time of the heating initial control.
The on-off valve 2 of the refrigerant introduction line 21 without flowing refrigerant as much as possible
2 is opened, the refrigerant is introduced into the refrigerant heater 8, and the refrigerant is heated with a specific combustion output and returned to the compressor 1. When the refrigerant temperature exceeds the lower limit set temperature (TEI (1)), the refrigerant introduction line The on / off valve 22 is closed to control the refrigerant to flow through the indoor heat exchanger 5.

During heating, the compressor 1 is operated with the ability to circulate the refrigerant without compressing it, so that the refrigerant flows through the bypass circuit 12 in order to ensure the amount of circulation, thereby ensuring the amount of refrigerant circulation.

FIG. 4 shows the change over time of the refrigerant temperature at the outlet of the refrigerant heater in the conventional control when the heating is started and the control according to the present invention.

In the conventional control, as shown by b, the cycle is not stabilized and hunting occurs.
As shown by, the cycle can be quickly stabilized.

[0037]

In summary, according to the present invention, a specific output lower than the normal combustion output range is set, and when the inlet refrigerant temperature enters the transitional temperature range, the combustion is not stopped as in the prior art. By operating with a specific combustion output, the cycle at the time of startup can be quickly stabilized and the operating range at the time of overload can be expanded.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an operation output and a combustion output in the present invention.

FIG. 3 is a diagram illustrating switching of combustion output with respect to condensation temperature in the present invention.

FIG. 4 is a diagram showing a change with time in a heating start-up operation according to the present invention and conventional control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Decompression device 5 Indoor heat exchanger 8 Refrigerant heater 28 Condensation temperature sensor

Claims (4)

(57) [Claims] 1. A circuit in which a compressor, a four-way valve, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger are sequentially connected, and a circuit in which a four-way valve and an indoor heat exchanger are sequentially connected to the compressor during heating operation. A refrigerant heater for heating the condensed refrigerant and returning it to the compressor, and controlling the refrigerant heater with a normal combustion output according to the outlet refrigerant temperature of the refrigerant heater. In the above, between the indoor heat exchanger and the refrigerant heater, a condensation temperature sensor that detects the refrigerant inlet temperature of the refrigerant heater, and a normal combustion output according to the refrigerant temperature of the refrigerant heater is set and the A specific combustion output that is lower than the minimum value of the normal combustion output is set, and a detection value of the condensation temperature sensor is input, and control means for switching from the normal combustion output to a specific combustion output based on the detection value of the condensation temperature sensor is provided. Characterized by having Refrigerant heating / cooling machine. 2. The control means according to claim 1, further comprising:
The refrigerant heating / cooling machine according to claim 1, wherein the specific combustion output is switched to when the refrigerant inlet temperature falls below a set lower limit. 3. The control means according to claim 1, wherein:
3. The refrigerant heating / cooling machine according to claim 1, wherein the specific combustion output is switched when the refrigerant inlet temperature exceeds a set upper limit. 4. The refrigerant heating / cooling machine according to claim 1, wherein the control means controls combustion of the refrigerant heater with a specific combustion output during a delay time of the initial control at the time of starting heating.