JPH07120117A - Defrosting device for heat pump - Google Patents

Abstract

PURPOSE:To obtain a defrosting device for a heat pump having a structure for starting a heating operation when water heating means of defrosting warm water heat storage means becomes a predetermined frosting occurring state. CONSTITUTION:The defrosting device for a heat pump comprises atmospheric state detecting means 3 for detecting a state of the air to absorb heat, a warm water heat storage tank 1 for storing warm water for defrosting, and heating means 2 for heating storage water in the tank. Control means H starts the heating of the means 2 based on detection information of the means 3 after the state of the air to absorb heat becomes a predetermined frosting occurring state, and previously heats to store warm water at the herald of frosting. Thus, it is not necessary to rapidly heat by large-capacity heating means or to heat and store warm water more than necessary irrespective of frosting, eliminates inconvenience of remarkably deteriorating performance of the pump in the case of starting the defrosting, inconvenience of steadily lowering original performance of the pump and reduces consumption energy as much as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to frost formation detecting means for detecting frost formation on a refrigerant evaporator which absorbs heat from air to be absorbed, and defrosting means for defrosting the frosted refrigerant evaporator with hot water. A control means for controlling the defrosting means is provided, and the control means is configured to start the defrosting operation of the defrosting means as the frosting is detected by the frosting detecting means. The present invention relates to a heat pump defrosting device.

[0002]

2. Description of the Related Art Conventionally, in this type of heat pump defrosting device, a defrosting means for defrosting a refrigerant evaporator with hot water is a hot water for defrosting as frost is detected by the frost detecting means. A hot water heat storage tank for starting heating or storing hot water for defrosting is provided, and is configured to constantly heat the water in the tank to store the hot water.

[0003]

However, according to the above-mentioned prior art, in order to quickly defrost the refrigerant evaporator without stopping the operation of the heat pump, it is necessary to detect frost formation as soon as possible. In the case of the type of starting heating of hot water, it is necessary to heat a large amount of hot water in a short time, so that a large capacity hot water heating means is required. Further, when using the hot gas of the heat pump for the hot water heating means in this type, a large amount of hot gas is used for the hot water heating as the defrosting operation is started, so the performance of the heat pump is significantly deteriorated. Thus, for example, there is an inconvenience that a trouble occurs in a heating operation of an air conditioner or the like.

Further, in the type that always stores hot water by heating the water in the hot water heat storage tank, the stored hot water is used to quickly defrost the frost on the refrigerant evaporator. However, unnecessarily heating hot water irrespective of frost formation is extremely long, and there is a disadvantage that energy consumption increases due to heat radiation from the tank. Also,
When using the hot gas of the heat pump for the hot water heating means in this hot water storage type, there is a disadvantage that the original performance of the heat pump is constantly reduced by constantly heating the water in the tank with the hot gas. It was

An object of the present invention is to eliminate the above-mentioned conventional drawbacks.

[0006]

A first characteristic configuration of a defrosting device for a heat pump according to the present invention is provided with an air state detecting means for detecting the state of air to be absorbed, and the defrosting means is for defrosting. A hot water heat storage tank for storing the hot water and heating means for heating the stored water in the tank are provided, and the control means determines the state of the heat absorption target air based on the detection information of the air state detection means. It is configured to start the heating operation of the heating means when the frost-producible state is reached.

The second and third characteristic constitutions of the heat pump defrosting device according to the present invention specify a preferable concrete constitution for carrying out the first characteristic constitution,

A second characteristic configuration is that the air condition detecting means is composed of a sensor for detecting the temperature or the humidity of the heat-absorption target air.

A third characteristic configuration is that the air to be endothermic is
It is composed of outside air, and the air condition detecting means is composed of weather detecting means for detecting weather.

[0010]

According to the first characteristic configuration of the present invention, the air condition detecting means for detecting the condition of the air to be absorbed is provided, the hot water heat storage tank for storing the hot water and the heating means are provided, and the control means absorbs the heat. Since the heating operation of the heating means is started when the state of the target air becomes a predetermined frost-producible state, warm water is preliminarily required as necessary for defrosting and prior to frost formation. Can be heated and stored.

According to the second characteristic configuration, since the air condition detecting means is composed of a sensor for detecting the temperature or the humidity of the heat absorption target air, the temperature of the heat absorption target air decreases or the humidity increases. Alternatively, by both of them, it is possible to detect that the state of the heat-absorption target air is changing toward the state in which frost is generated, and the state in which frost may occur in the future, that is, It is possible to detect the possible frost formation state.

According to the third characteristic configuration, since the heat-absorption target air is constituted by the outside air and the air condition detecting means is constituted by the weather detecting means for detecting the weather, the condition of the weather and the change of the weather are changed. From this, it is possible to predict that the outside air state, which is the heat-absorption target air, changes toward the state in which frost formation occurs, and the frost formation possible state can be detected.

[0013]

According to the first characteristic configuration of the present invention, hot water can be heated and stored in advance as needed for defrosting and prior to frost formation. It is not necessary to heat the hot water promptly by the heating means or to unnecessarily heat and store the hot water regardless of the frost formation. Therefore, the inconvenience that the heating means needs to have a large capacity and the defrosting operation The performance of the heat pump is significantly deteriorated with the start of, and the inconvenience of hindering the heating operation of the air conditioner and the like and the inconvenience of the original performance of the heat pump constantly decreasing are solved, and the energy consumption is reduced. It is possible to provide a defrosting device for a heat pump that has been reduced as much as possible.

According to the second characteristic configuration, the predetermined frost formation possible state can be detected by the decrease in the temperature of the heat-absorption target air, the increase in the humidity, or both of them. Therefore, the frost formation can be accurately performed. It is possible to detect a possible state, and therefore when necessary for defrosting and prior to frost formation,
A defroster for a heat pump that can reliably heat and store hot water can be provided.

According to the third characteristic configuration, the predetermined frost formation possible state can be detected even from the state of the weather and the change of the weather, so that the frost formation possible state can be accurately detected. Therefore, it is possible to provide a defrosting device for a heat pump that can reliably heat and store hot water as needed before defrosting and prior to frost formation.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a separate type heat pump type air conditioner, where Uo is an outdoor unit, Ua is a first indoor unit for a first air conditioning target area Za, Ub is a second indoor unit for a second air conditioning target area Zb, and Uc is a first indoor unit. It is the third indoor unit for the three air conditioning target areas Zc.

In the outdoor unit Uo, there are two outdoor heat exchangers No1 and No2 that use the outdoor air OA as air to be absorbed and radiated, and an outdoor fan F1 that ventilates the outdoor air OA to the outdoor heat exchangers No1 and No2. F2, compressor Cmp, accumulator Ac, oil separator Os, and receiver R
And a first expansion valve ex1 for the outdoor heat exchanger No1 and a second expansion valve ex2 for the outdoor heat exchanger No2.

Reference symbols v1 to v4 are switching valves for switching the refrigerant circuit in accordance with the operation mode. The switching valves v1 and v3 are
The paths for returning the low-pressure gas refrigerant Rc from the outdoor heat exchanger No1 or No2 to the accumulator Ac are each configured to be interrupted. The switching valves v2 and v4 are the compressor Cmp.
The high pressure gas refrigerant Rh discharged from the heat exchanger is connected to the outdoor heat exchanger No1 or No2.

First expansion valve ex1 and second expansion valve ex2
Is provided in a path that allows the liquid refrigerant Rw to flow between the outdoor heat exchanger No1 or No2 and the liquid receiver R, and when the liquid refrigerant Rw flows toward the outdoor heat exchangers No1 and No2. When the liquid refrigerant Rw flows toward the liquid receiver R, it can be switched so as to function as an original refrigerant expansion means.

Reference numeral ro is an oil return pipe for joining the compressor oil captured by the oil separator Os to the low pressure gas refrigerant Rc to be sucked into the compressor Cmp from the accumulator Ac and returning it to the compressor Cmp.

From the outdoor unit Uo, the high pressure gas main pipe Gh for sending the high pressure gas refrigerant Rh discharged from the compressor Cmp to the indoor unit side.
And a low pressure gas main pipe Gc for returning the low pressure gas refrigerant Rc from the indoor unit side to the accumulator Ac of the outdoor unit Uo, and the liquid refrigerant Rw between each indoor unit Ua, Ub and Uc and the receiver R of the outdoor unit Uo. The three liquid main pipes W for circulating the liquid are extended.

Each of the first, second and third indoor units Ua, Ub and Uc is provided with an indoor heat exchanger Ni for adjusting the supply air SAa, SAb and SAc to the corresponding air conditioning target areas Za, Zb and Zc. , The air SAa, SAb and SAc adjusted by these indoor heat exchangers Ni are used as the corresponding air conditioning target area Z.
An air supply fan F3 that supplies a, Zb, and Zc and a third expansion valve ex3 for the indoor heat exchanger Ni are provided.

V5 and v6 are switching valves for switching the refrigerant circuit in accordance with the operation mode. The switching valve v5 is configured to connect and disconnect the high-pressure gas branch pipe rh that sends the high-pressure gas Rh from the high-pressure gas main pipe Gh to the indoor heat exchanger Ni, respectively. The switching valve v6 is a low pressure gas recirculation pipe rc for returning the low pressure gas Rc from the indoor heat exchanger Ni to the low pressure gas main pipe Gc.
Are configured to be intermittent.

The third expansion valve ex3 is provided between the indoor heat exchanger Ni and the liquid main pipe W in the liquid-refrigerant Rw flowing through the liquid branch reflux pipe rw, and the liquid refrigerant Rw is supplied to the indoor heat exchanger Ni. When the liquid refrigerant Rw flows toward the liquid main pipe W, it functions as the original refrigerant expansion means. On the other hand, when the liquid refrigerant Rw flows toward the liquid main pipe W, it functions as a flow rate adjusting valve. Has been done.

The high pressure gas branch pipe rh is connected to the high pressure gas main pipe Gh via a refrigerant distributor A. The low-pressure gas recirculation pipe rc is connected to the low-pressure gas main pipe Gc via the refrigerant junction B. The liquid branch / reflux pipe rw is a refrigerant diverting / combining device C.
It is connected to the liquid main pipe W via.

When the fourth and subsequent indoor units are installed, the fourth and subsequent indoor units are also connected to the three main pipes Gh, Gc and W in the same connection form as described above. It

Further, the outdoor unit Uo is provided with a control unit H of the heat pump type air conditioner. The control unit H is mainly composed of a microcomputer, and is configured to be able to control various operations of the heat pump type air conditioner by software incorporated therein.

FIG. 1 shows the outdoor heat exchanger N of the outdoor unit Uo.
While making o1 and No2 function as an evaporator Ev to absorb heat from the ventilation outside air OA, the indoor unit Ua,
The operating state of the "heating mode" in which the indoor heat exchangers Ni of Ub and Uc are caused to function as the condenser Cd to heat the passing air SAa, SAb, and SAc by heating is shown.

That is, as a specific refrigerant flow, the high-pressure gas refrigerant Rh discharged from the compressor Cmp and passing through the oil separator Os (shown by a thick black line in the drawing) is a high-pressure gas main pipe Gh and a high-pressure gas branch pipe. Through rh, it is distributed and supplied to the indoor heat exchangers Ni of the indoor units Ua, Ub, and Uc to be condensed, and the heating temperature is adjusted.

The condensate refrigerant Rw (indicated by a thick hatched line in the figure) sent from the indoor heat exchanger Ni as the condenser Cd is the third expansion valve ex3 in the switched state which functions as a flow rate adjusting valve. It is returned to the liquid receiver R of the outdoor unit Uo via the liquid branch reflux pipe rw and the liquid main pipe W. The condensed liquid refrigerant Rw returned to the liquid receiver R is the first and second expansion valves ex1 and ex2 in the switching state to function as the original refrigerant expansion means.
After being distributed and supplied to the outside heat exchangers, the heat is evaporated in the outdoor heat exchangers No1 and No2 as the evaporator Ev.

The evaporated low-pressure gas refrigerant Rc (shown by a white thick line in the figure) sent from the outdoor heat exchangers No1 and No2 is returned to the compressor Cmp via the switching valve v1 or v3 and the accumulator Ac. . (In the figure, the black-painted valve indicates the closed state.) Hereinafter, this circulation is repeated to configure the heat pump.

In the outdoor unit Uo, the outside air state detecting means 3 for detecting the state of the outside air OA, and the frost formation for detecting the frost formation of the outdoor heat exchanger No1 or No2 as a refrigerant evaporator which absorbs heat from the outside air OA. Detection means S1 and S2 and defrosting means Df for defrosting the frosted outdoor heat exchanger No1 or No2 with hot water are provided.

In this embodiment, the outside air state detecting means 3
Is an outside air temperature sensor S5 that detects the temperature Ta of the outside air OA.
And an outside air humidity sensor S6 for detecting the humidity Ma of the outside air OA
It consists of and. The outside air temperature sensor S5 and the outside air humidity sensor S6 are connected to the control unit H.

In the present embodiment, the frost formation detecting means is composed of refrigerant temperature sensors S1 and S2 for detecting the refrigerant temperature Tr near the refrigerant outlets of the outdoor heat exchangers No1 and No2, respectively. The coolant temperature sensors S1 and S2 are also connected to the control unit H.

The defrosting means Df is a hot water nozzle n1 for spraying hot water for defrosting on each of the outdoor heat exchangers No1 and No2.
And n2 and hot water pumps p1 and p2 provided in hot water supply pipes for supplying hot water to the hot water nozzles n1 and n2.
And a hot water heat storage tank 1 for storing hot water for defrosting, and an electric heater 2 as a heating means for heating the stored water in the tank 1. Hot water pumps p1 and p2
Are connected to the control unit H. The hot water heat storage tank 1 has a water level sensor S for detecting the water level in the tank by water pressure.
3 and a water temperature sensor S4 for detecting the temperature of hot water in the tank
And are provided. Water level sensor S3 and water temperature sensor S
4 is also connected to the control unit H.

The function of the controller H is that the outside air temperature Ta detected by the outside air temperature sensor S5 reaches a predetermined temperature or the outside air humidity Ma detected by the outside air humidity sensor S6 reaches a predetermined humidity. Along with this, an outside air state determination unit 101 is configured to determine that the outside air state has reached a predetermined frost formation possible state. In this embodiment, the predetermined temperature is set to an appropriate value of about -3 ° C to + 2 ° C, and the predetermined humidity is set to an appropriate value of about 60% to 95%.

Further, the control unit H causes the outdoor heat exchanger No. 1 or N to follow the detected refrigerant temperature Tr as it falls to a predetermined temperature lower than the normal value in the operating state of the "heating mode".
Frost determination means 10 for determining that frost is generated on o2
2 and defrost control means 103 that controls the defrosting operation of the defrost means Df.

The defrost control means 103 opens the water supply valve 4 to start pouring water into the hot water heat storage tank 1 as the frost formation possible state is determined by the outside air state determination means 101, and the electric heater 2, heating of the stored water in the tank 1 is started. Then, thereafter, the temperature of the hot water is maintained at a predetermined temperature based on the detection information of the water temperature sensor S4. In the present embodiment, the predetermined temperature is 15 ° C. to 20 ° C.
It is set to an appropriate value. Further, the water level of the stored water in the hot water heat storage tank 1 is maintained at a predetermined water level by connecting and disconnecting the water supply valve 4 based on the detection information of the water level sensor S3.

Therefore, the control unit H has the outside air state detecting means 3
Based on the detection information of the outside air temperature sensor S5 and the outside air humidity sensor S6 as the control means for starting the heating operation of the electric heater 2 as the heating means when the outside air state reaches a predetermined frost-producible state. Has been done.

Further, the defrosting control means 103 causes the hot water pump p to follow the frost formation determined by the frost formation determination means 102.
1 or p2 is driven to sprinkle water from the hot water nozzles n1 or n2 to defrost the outdoor heat exchanger No1 or No2.
At this time, when the temperature below the predetermined temperature is detected by the refrigerant temperature sensor S1 provided near the refrigerant outlet of the outdoor heat exchanger No1, the hot water pump p1 is driven and the refrigerant of the outdoor heat exchanger No2 is driven. When the temperature sensor S2 detects a temperature equal to or lower than the predetermined temperature, the hot water pump p2 is driven.

Therefore, the control section H is constituted as a control means for starting the defrosting operation of the defrosting means Df as the frost formation is detected by the refrigerant temperature sensor S1 or S2 as the frost detection means. There is.

As the operation mode of the heat pump by the control unit H, a "cooling mode" and a "cooling / heating simultaneous mode" can be implemented in addition to the "heating mode".

In the "cooling mode", the switching valves v2 and v4 of the outdoor unit Uo are opened, and the switching valves v1 and v4 are opened.
3 is closed, the switching valve v6 of the indoor units Ua, Ub, and Uc is opened, and the switching valve v5 is closed, so that the outdoor heat exchangers No1 and No2 function as a condenser Cd, and The heat exchanger Ni functions as the evaporator Ev.

The "cooling / heating simultaneous mode" is the indoor unit Ua, Ub.
Alternatively, the indoor heat exchanger Ni functioning as the condenser Cd is operated by opening / closing the respective switching valves v5 and v6 of Uc.
This is the operation mode in which both the indoor heat exchanger Ni functioning as the evaporator Ev and the indoor heat exchanger Ni are present. The "cooling / heating simultaneous mode" includes "a cooling / heating simultaneous mode in which the outdoor heat exchanger functions as an evaporator Ev" and "a cooling / heating simultaneous mode in which the outdoor heat exchanger functions as a condenser Cd".

[Other Embodiments] The outside air state detecting means 3 is not limited to the above outside air temperature sensor S5 and outside air humidity sensor S6, but can be changed as appropriate. For example, a pressure sensor that detects the pressure of the outside air OA may be used, or a weather detection unit that detects the weather may be used. As the weather detecting means, for example,
It may be snowfall detecting means for detecting snowfall, or rainfall detecting means for detecting rainfall, or cold / rainfall detecting means by detecting the temperature of rainwater. Further, the outside air state information, the weather information, the weather forecast, and the like are provided to the outside air state determination means 1 of the control unit H by the weather information online service.
It may be directly input to 01.

The outside air condition judging means 101 determines the outside air temperature Ta.
It may be configured such that the frost formation possible state is discriminated when both the outside air humidity Ma and the outside air humidity Ma reach a predetermined value, and the detected atmospheric pressure and the like are added and a table showing a moist air diagram and the like. It may be configured to determine the possible frost formation state by collating with.

The frost detection means is the above-mentioned refrigerant temperature sensor S.
It is not limited to 1 and S2, but can be changed as appropriate. For example, it may be a refrigerant pressure sensor that detects the refrigerant pressure in the vicinity of the refrigerant outlet of the outdoor heat exchanger No1 or No2, or a conductive terminal that conducts electricity due to frost formation.

The heating means of the defrosting means Df is not limited to the electric heater 2 described above, but can be changed appropriately. For example, the heating means is composed of a heat exchanger for exchanging heat between the hot gas of the heat pump and the stored water of the hot water heat storage tank 1, and the hot gas is intermittently supplied to the heat exchanger to thereby perform the heating operation of the heating means. It may be configured to start or stop.

Further, the defrosting mode of the defrosting means Df is not limited to the one in which hot water is sprayed by the hot water nozzles n1 and n2 as in the above-mentioned embodiment, but can be changed appropriately. For example, in the vicinity of the frosted portions of the outdoor heat exchangers No1 and No2, hot water,
Alternatively, a flow path for passing hot gas may be provided, and the flow of hot water or hot gas may be started when frost is detected by the frost detection means S1 or S2. .

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an overall configuration of a heat pump type air conditioner.

[Explanation of symbols]

 Df Defrosting means Ma Humidity No1 Refrigerant evaporator No2 Refrigerant evaporator OA Outside air (heat absorption target air) S1 Frost detection means S2 Frost detection means Ta temperature 1 Hot water heat storage tank 2 Heating means 3 Outside air state detection means 103 Control means

Claims (3)

[Claims] 1. Frost detection means (S1, S2) for detecting frost formation on a refrigerant evaporator (No1, No2) that absorbs heat from heat-absorption target air (OA), and a frosted refrigerant evaporator (No1, N2).
Defrosting means (Df) for defrosting o2) with hot water and control means (103) for controlling the defrosting means (Df) are provided, and the control means (103) is for the frost formation detecting means ( S1,
A defrosting device for a heat pump, which is configured to start the defrosting operation of the defrosting means (Df) in accordance with the detection of frost formation in S2). An air condition detecting means (3) for detecting the temperature is provided, and the defrosting means (Df) is provided with a hot water heat storage tank (1) for storing hot water for defrosting, and heating for heating the stored water in the tank. Means (2) is provided, and the control means (103) heats when the state of the heat-absorption target air reaches a predetermined frost formation-producible state based on the detection information of the air state detection means (3). Means (2)
Defrosting device for a heat pump configured to start the heating operation of the. 2. The air condition detection means (3) is composed of sensors (S5, S6) for detecting the temperature (Ta) or the humidity (Ma) of the heat-absorption target air (OA). The heat pump defrosting device described. 3. The heat pump according to claim 1, wherein the heat-absorption target air is composed of outside air (OA), and the air condition detecting means (3) is composed of weather detecting means for detecting weather. Defroster.