JP2002286318A - Air conditioner and condenser used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the evaporating function of a condenser in a heating operation for meeting low temperature in the winter season and a cold place so as to realize a comfortable heating, by avoiding the deterioration of a heating capacity resulting from the deterioration of the function of the condenser due to the fall of atmospheric air temperature, or the stop of the heating operation resulting from the adherence of frost to the condenser when the heating operation is carried out with an air conditioner. SOLUTION: A heat generating member for heating the condenser is provided in a refrigerant passage or inside/outside of the condenser. In a cooling operation, a refrigerant does not pass the refrigerant passage in which the heat generating member is provided, or the heat generating member is not used. A second-stage condenser is provided in the upstream of the condenser (first-stage condenser). The second-stage condenser and the first-stage condenser are arranged in parallel in the direction where a heat exchanging material passes, and arranged in such a manner that the heat exchanging material firstly passes the second-stage condenser and then passes the first-stage condenser. Heat taken by the heat exchanging material during a process in which the heat exchanging material passes the second-stage condenser is effectively transferred to the first-stage condenser.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condenser for an air conditioner, and more particularly to a condenser for an air conditioner improved to be environmentally friendly, and an air conditioner using the condenser. .

[0002]

2. Description of the Related Art When the air temperature decreases during a heating operation in an air conditioner, the heat exchange capability of the condenser, that is, the capability of absorbing heat from the atmosphere decreases, and the heating capability decreases. In order to compensate for this, usually, an electric heater and a heating wire are provided in the indoor unit, and the blown air is heated to compensate for a decrease in the heating capacity. Further, when the atmospheric temperature drops to about 0 ° C., frost adheres to the surface of the condenser, and the heat exchange ability is drastically reduced, and the heat absorption function of the refrigerant through heat exchange between the refrigerant passing through the condenser and the atmosphere. Is stopped. Since the refrigerant does not evaporate, the refrigerant enters the compressor in a liquid phase state, causing a problem of damaging the compressor, so that the heating operation is stopped. In order to remove the frost adhering to the condenser, usually, a defrosting operation is performed in which the flow direction of the refrigerant is reversed and the refrigerant of the high-temperature and high-pressure gas is sent from the compressor to the condenser, so that the heating is stopped. Further, even when the heating operation is restarted, it is impossible to predict when frost will recur. As a result, the heating of the air conditioner loses reliability at low temperatures or in cold regions, and the heating depends on the heat generated by the combustion of fossil fuels. Recently, in order to solve the above-mentioned problem caused by a decrease in the temperature of the outside air, a system in which a condenser is externally heated by a combustor using kerosene to externally heat a refrigerant in the condenser has been commercialized. For the time being, the purpose of improving the heating capacity and continuing the heating operation is fulfilled, but the efficiency of heating the condenser from the outside is low, and the burning of kerosene generates CO2, causing environmental pollution.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent a decrease in the heating capacity due to a decrease in the atmospheric temperature and a stoppage of the heating operation due to frost on the condenser in the heating of the air conditioner. Keep the external surface temperature of the
Another object of the present invention is to provide a condenser and an air conditioner that use energy such as wind power, solar power, fuel cell, and nuclear power so as not to cause air pollution. Also, conventionally, cold regions, such as Sanin, Hokuriku, Tohoku region,
It is another object of the present invention to provide an environment-friendly and economical device that enables heating by an air conditioner even in an area where the minimum temperature in winter is about 10 degrees below zero degrees Celsius in Europe, North and South America, and the like. Further, an object of the present invention is to provide a condenser capable of preventing a decrease in heating capacity and stopping a heating operation by adding a heating element to the condenser without significantly modifying a conventional air conditioner. To provide.

[0004]

[Means for Solving the Problems] In the heating operation, an evaporator provided in the indoor unit exchanges heat with the refrigerant of the high-temperature and high-pressure gas coming from the compressor with the indoor air to reduce the indoor air temperature. To raise. The refrigerant leaving the evaporator becomes a liquid at room temperature and high pressure. Next, the refrigerant expanded through the capillary downstream of the evaporator becomes low-temperature, low-pressure wet steam and enters the condenser.
It absorbs the heat of the atmosphere and evaporates into low-temperature, low-pressure superheated steam, which is sent to the refrigerant accumulator. In the refrigerant accumulator, a liquid-phase refrigerant accumulates in a lower portion, and a gas-phase refrigerant exists in an upper portion. Next, the refrigerant in a gaseous state enters the compressor, is adiabatically compressed, becomes a high-temperature high-pressure gas refrigerant, and is sent to the evaporator. The heating operation is performed in such a refrigeration cycle.

[0005] Therefore, if the capacity of the condenser to absorb the retained heat of the atmosphere decreases due to the decrease in the atmospheric temperature or if frost adheres to the surface of the condenser, the condenser is heated by some method to increase the capacity. It is necessary to maintain the surface temperature of the condenser so as to compensate for the drop and, at worst, not to cause the compressor to stop due to frost on the condenser. When the ambient temperature is low and the liquid phase of the refrigerant entering the refrigerant accumulator from the condenser increases and liquid phase refrigerant enters the compressor from the refrigerant accumulator, the compressor is overloaded because the liquid refrigerant is an incompressible fluid. Or, depending on the type of compressor, the compressor will be damaged and the compressor will stop.

A first means for solving the above-mentioned problem is to provide a heating element inside or / and outside the refrigerant passage of the condenser, to transfer generated heat of the heating element to the condenser, and to increase the surface temperature of the condenser. Is to hold or rise.

Specifically, when a heating element is provided in the refrigerant passage, a plurality of heating elements are provided near the entrance or in the middle between the entrance and the exit in the flow direction of the refrigerant, and the refrigerant passing through the condenser is provided. To transfer the heat of the refrigerant to the condenser. In addition, the heating element is arranged inside and / or outside the refrigerant passage of the condenser along the refrigerant passage, and transfers generated heat of the heating element to the condenser. It should be noted that the refrigerant passes through the refrigerant passage provided with the heating element during the heating operation, and does not pass through the refrigerant passage provided with the heating element during the cooling operation. When the heating element is arranged along the refrigerant passage, the heating element is used in the heating operation and is not used in the cooling operation.

[0008] As a second means, in order to heat the condenser efficiently, a second-stage condenser is provided upstream of the condenser (hereinafter referred to as a first-stage condenser). By providing a heating element similar to that of the first-stage condenser, heat exchange products (hereinafter, “atmosphere”) passing through the second-stage and first-stage condensers first pass through the second-stage condenser, and then pass through the first-stage condenser. Arrange so as to pass through the condenser. Thereby, in the process of passing the air through the second-stage condenser, heat taken from the second-stage condenser is given to the first-stage condenser, and the surface temperature of the first-stage condenser is maintained or increased. be able to. The refrigerant passage of the second stage condenser is a second passage.
It is formed by a cross-sectional area reducing passage smaller than the cross-sectional area on the upstream side and the downstream side of the stage condenser, and the refrigerant passage of the second stage condenser is branched into a plurality of passages to improve the heat exchange ability. Therefore, the heat generated by the condensation operation of the second-stage condenser can be efficiently transmitted to the first-stage condenser.

As a third means, the first stage and the second stage
Whether the heating element provided in the stage condenser is not used, is used independently, is used in combination of both, or is manually operated or automatically controlled depends on the type of refrigerant, the atmospheric temperature, and the heating load. Judgment is made comprehensively and the selection is made to heat the condenser efficiently. In addition, a thermometer / hygrometer for measuring the surface temperature / humidity of the first-stage condenser and the second-stage condenser and the temperature / humidity of the atmosphere before and after was provided, and the measured values were used to prepare in advance. According to the optimal heating operation program, automatic control for increasing or decreasing the amount of heat generated by the heating elements of the first-stage condenser and the second-stage condenser is performed, so that the optimal heating operation is performed.

[0010] As a fourth means, the air volume of the atmosphere for performing heat exchange with the first-stage condenser and the second-stage condenser is changed to the state of the atmosphere,
Increase or decrease in relation to the type of refrigerant, etc. to improve the heat exchange capacity.

An air conditioner according to another aspect of the present invention relates to an air conditioner in which a refrigerant changes its state in the order of evaporation → compression → condensation → decompression → evaporation and circulates to perform a refrigeration operation. Refrigerant
An air conditioner in which a heating element is provided in a condenser of an air conditioner that circulates through a condenser, a compressor, an evaporator, a capillary (a decompressor), and a condenser.

[0012]

[Embodiment 1] An air conditioner using an existing refrigerant R22 was used to perform a heating operation in an environmental test room. The heat exchanger is the atmosphere. An electric heater was used as a heating element for heating the condenser. The capacity of the existing air conditioner is 12000
kCAL / h, and the rating of the compressor driving motor is 3
The phase was 220 V, 60 Hz, the output was 3.7 kW, and the type of the compressor was a hermetically sealed type in which the compressor and the electric motor were housed in the same container.

FIG. 1 is a conceptual diagram of an existing air conditioner. In the heating operation, the refrigerant is supplied from the refrigerant accumulator S to the compressor 2.
Into a high-temperature, high-pressure gas, and a four-way valve RV
Through the operating valve V1, enters the evaporator 1 in the indoor unit 6 and becomes a liquid at normal temperature and high pressure, expands in the capillary 4 to become low-temperature and low-pressure wet steam, and condenses in the outdoor unit 7 via the operating valve V2. The heat of the atmosphere is absorbed by the heat exchanger 3 to become a low-temperature, low-pressure superheated steam, and returns to the refrigerant accumulator S. In addition, the cooling operation can be performed by switching the four-way valve RV and flowing the refrigerant in the opposite direction to the heating operation.

In FIG. 1, when the atmospheric temperature Ti is 5 ° C., Te is 0 ° C., t1 is 55 ° C., t2 is 5 ° C., t3 is 40 ° C., T1
Was 18 ° C., T2 was 30 ° C., and the power consumption was 4.0 kW.

[Embodiment 2] Next, when the atmospheric temperature Ti is lowered to -5 ° C in FIG. 1, T1 is 15 ° C and T2 is 19 ° C.
And the compressor became overloaded and stopped after about 15 minutes. The power used at that time was 6 kW. It was observed that frost adhered to the condenser 3 in pure white, and no heat exchange action between the condenser 3 and the outside air was performed.

[Embodiment 3] Then, the atmospheric temperature Ti was set to 15
After the temperature was raised to ° C. to remove the frost from the condenser, an electric heater A and check valves AV1 and AV2 were additionally provided upstream of the condenser 3 in FIG. 1 as shown in FIG. By these check valves, the refrigerant passes through the electric heater A during the heating operation and forms a refrigerant passage that does not pass through the electric heater A during the cooling operation.

Referring to FIG. 3, the output of electric heater A is 0-1.
Output setting device C that performs manual operation or automatic control at 0 kw
FIG. 2 is a conceptual diagram of an apparatus for increasing / decreasing the amount of heat generated by an electric heater A by using a voltage adjusting element Th-A attached to the heater. In the case of automatic control, the measured value T
By inputting i, Ts, and Te, the output of the electric heater A is automatically controlled.

Next, in FIG. 2, the atmospheric temperature Ti was lowered to -5.degree. The output of the electric heater A is manually adjusted to adjust the output of the electric heater A so that the thermometer Ts provided on the air outlet side surface of the condenser 3 becomes 3 ° C., and the heating operation can be continued for 3 hours. Was. T1 is 16 ° C., T2 is 20 ° C., t1 is 5
4 ° C, t2 is 5 ° C, t3 is 39 ° C, Ti is -5 ° C, Ts
Was 3 ° C., Te was 0 ° C., the output of the electric heater A was 8 kW, and the electric power used other than the electric heater A was 4.5 kW.

FIG. 4 is a conceptual diagram of an apparatus in which the second-stage condenser 5 is additionally provided in FIG. 2. The cross-sectional area of the refrigerant passage of the second-stage condenser 5 is upstream and downstream of the second-stage condenser 5. 1/2 of the cross-sectional area on the side
And has a four-branch refrigerant passage, and its heat exchange capacity is 5000
kCAL / h.

Referring to FIG. 5, electric heater A and electric heater B
Is an output of 0 to 10 kw, and is a conceptual diagram of a device for increasing or decreasing the amount of heat generated by the electric heater A and the electric heater B by the voltage adjusting elements Th-A and Th-B attached to the output setting device C which performs manual operation or automatic control. It is. In the case of automatic control, the measurement values Ti, Tm,
By inputting Ts and Te, the outputs of the electric heaters A and B are automatically controlled.

Example 4 Next, in FIG. 4, the atmospheric temperature Ti was further lowered from -5 ° C. A thermometer Ts provided on the outer surface of the second-stage condenser without using the electric heater A
The electric heater B was operated for 3 hours while manually increasing the output so that the temperature became 3 ° C. T1 at that time is 18 ° C, T
2 is 28 ° C., t1 is 56 ° C., t2 is 6 ° C., t3 is 42
℃, Ti -7 ℃, Ts 3 ℃, Te 0 ℃, electric heater B
Was 5 kW, and the other power consumption was 4.3 kW.

[Embodiment 5] The air conditioner shown in FIG.
2 was taken out, replaced with refrigerant HFC-134a, and a heating operation was performed. While lowering the atmospheric temperature Ti from 0 ° C., without using the electric heater A, the output of the electric heater B was manually increased, and a thermometer Ts provided on the surface of the first stage condenser on the atmospheric outlet side was used. The temperature was adjusted to 3 ° C. The output of the electric heater B at that time was 6 kW. T1 is 18 ° C, T2
Is 28 ° C, Ti is -5 ° C, Tm is -1 ° C, Te is 3 ° C,
ti is 55 ° C, t2 is 4 ° C, t3 is 41 ° C, and t4 is 20
° C, electric power used other than the electric heater was 3.5 kW. Thereafter, the operation was continued for 3 hours, and it was confirmed that there was no change in the temperature of each thermometer. [Example 6]

In FIG. 4, the output of the first stage condenser is reduced while the output of the heater B is fixed at 6 kW and the temperature of the atmosphere Ti is lowered from −5 ° C. by using the electric heater A and the electric heater B together. The thermometer Ts provided on the side surface was set at 3 ° C., and the output of the electric heater A was automatically controlled. In addition, the air volume of the air passing through the first and second stage condensers was increased by 20%. After 3 hours, the output of the heater A is stabilized at 4 kW, T1 is 20 ° C.,
T2 is 30C, Ti is -10C, Tm is -4C, Te is 0C, t1 is 56C, t2 is 6C, t3 is 42C, and t4.
Was 21 ° C., and the power used other than the electric heater was 3.8 kW. Conventionally, heating operation was impossible when the ambient temperature was -10 ° C, but the additional heating element enabled stable heating as described above.

Means for transmitting the heat generated by the electric heater or the heating wire to the refrigerant passing through the refrigerant passage may be used when the electric heater is used alone as in the above example, or when used in combination with a plurality of electric heaters. For example, when using a heating wire arranged along the refrigerant passage, the selection can be made in consideration of the type of the refrigerant, the state of the atmosphere, and the like.

The following has been confirmed from the above examples.
After the frost has adhered to the condenser, when the refrigerant is heated by manual operation, and by detecting changes in the atmospheric temperature and the condenser surface temperature,
For example, when automatic control is performed by an optimal control program so that the surface temperature of the condenser becomes 3 ° C., comfortable heating can be performed in the latter case. If defrosting is performed after the frost has adhered to the condenser, there is a problem that heating is interrupted for a long time. When the third embodiment and the fourth embodiment are compared, the output of the electric heater B is smaller than the output of the electric heater A, and the same object can be achieved. Therefore, the heating efficiency of the fourth embodiment is better. In Examples 5 and 6, the electric heaters A and B were used alone or
It was confirmed that the heating capacity was improved by using the combination and increasing or decreasing the air volume. It has also been confirmed that in areas where the heating operation drops below zero degrees Celsius, it is possible to achieve comfortable heating that was previously impossible.

Referring to FIG. 6, P is a conduit which is a refrigerant passage of the condenser, and HE is a heating wire in the conduit. Heating wire HE
FIG. 3 is a conceptual diagram of installation along a pipe so that heat generated by the heat is efficiently transmitted to a condenser through a refrigerant passing through the refrigerant.

FIG. 7 shows a case in which a rectangular heating element is provided outside the refrigerant passage, and the heating element is integrated along the outside of the refrigerant passage of the condenser so as to maintain or increase the surface temperature of the condenser. It is a conceptual diagram. 10 is a condenser tube, 11 is a refrigerant passage, 12
Is a heating element.

FIG. 8 shows a circular heating element placed outside the circular refrigerant passage so as to maintain or increase the surface temperature of the condenser.
It is the conceptual diagram which installed the heating element along the refrigerant | coolant path | pass of the condenser, and supported by the heat exchange fin. Reference numeral 10 denotes a condensing tube, 11 denotes a refrigerant passage, 12 denotes a heating element, and 13 denotes a heat exchange fin.

The embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0030]

As described above, a heating element is provided in a condenser of an existing air conditioner, and a device for heating the condenser is additionally provided, whereby the heating capacity is reduced due to a decrease in the outside air temperature in the heating operation. Further, it is possible to prevent the heating operation from being stopped due to frost on the condenser.

In addition, heating elements are provided in the first and second stage condensers from the beginning, and the condensers are heated, and the optimum design is performed so as to maintain or increase the surface temperature of the condensers. An environment-friendly heating device that is not used can be provided.
In addition, since the options of the optimal design / production method of the air conditioner increase, it contributes to the development of the air conditioner.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a conventional air conditioner in a heating operation.

FIG. 2 is an example of a conceptual diagram in a heating operation of the present invention.

FIG. 3 is a conceptual diagram of a control device of an electric heater A provided in FIG.

FIG. 4 is an example of a conceptual diagram in a heating operation of the present invention.

FIG. 5 is a conceptual diagram of a control device for an electric heater A and an electric heater B provided in FIG.

FIG. 6 is a conceptual diagram of installing a heating wire in a refrigerant passage of a condenser.

FIG. 7 is a conceptual diagram in which a heating element is arranged along the outside of a refrigerant passage of the condenser and integrated with the condenser.

FIG. 8 is a conceptual diagram in which a heating element is installed along the outside of a refrigerant passage of a condenser and supported by heat exchange fins.

[Explanation of symbols]

1 evaporator, 2 compressor, 3 condenser (first stage condenser), 4 heating capillary, 4-1 cooling capillary, 5 second stage condenser, RV four-way valve, S refrigerant accumulator, A electric heater, B electric heater, V1 operating valve, V
2 Operating valve, OV1 check valve, AV1 check valve, AV2
Check valve, BV1 check valve, BV2 check valve, A1 electric heater terminal, A2 electric heater terminal, B1 electric heater terminal,
B2 Terminal of electric heater, Ti heat exchanger (atmosphere) condenser (first stage condenser) entrance thermometer / hygrometer temperature, Te
Temperature of the condenser outlet thermometer / hygrometer of the atmosphere, Tm Temperature of the second stage condenser outlet thermometer / hygrometer of the atmosphere, Te Temperature of the first stage condenser outlet thermometer / hygrometer of the atmosphere, Ts first Temperature of thermometer / hygrometer provided on the outer surface of the stage condenser, t1
Refrigerant temperature between evaporator and compressor, t2 Refrigerant temperature between compressor and condenser, t3 Refrigerant temperature between condenser and heating capillary, t4 Between first-stage condenser and second-stage condenser Refrigerant temperature, T1 evaporator suction air temperature, T2 evaporator air temperature, 6 indoor units, 7 outdoor units, C
Output setting device, Th-A voltage adjusting element, Th-B voltage adjusting element, pipe as refrigerant passage of P condenser, HE heating wire, 10 condenser pipe, 11 refrigerant passage, 12 heating element,
13 Heat exchange fins.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 1/00 321 F25B 1/00 321B 6/04 6/04 Z

Claims (3)

[Claims] In an air conditioner, a heating element is provided inside and / or outside of a refrigerant passage of a condenser, and heat generated by the heating element is transmitted to the condenser to maintain or increase the surface temperature of the condenser. Do, condenser. 2. An air conditioner for circulating a refrigerant by changing the state of evaporation → compression → condensation → decompression → evaporation to perform a refrigeration operation, wherein a second stage condenser is provided in the refrigerant passage. A first condenser (hereinafter referred to as a first condenser), the second condenser and the first condenser are arranged side by side in a direction in which the heat exchange material passes, and An article is arranged to first pass through the second stage condenser and then pass through the first stage condenser, wherein a heating element is provided in and / or outside the refrigerant passage of the second stage condenser. To transfer the heat generated by the heating element to the second-stage condenser, and remove the heat taken from the second-stage condenser in the process of the heat exchange passing through the second-stage condenser. An air conditioner that communicates to a stage condenser to maintain or increase the surface temperature of the first stage condenser. 3. A condenser for an air conditioner, wherein a thermometer and a hygrometer are provided on the outer surface of the condenser before and after a passage through which the heat exchanger passes through the condenser, and the measured values of the thermometer and the hygrometer are measured. The air conditioner according to claim 1 or 2, further comprising a control device for increasing / decreasing the amount of heat generated by a heating element provided in the condenser using the controller.