JPS63135753A - Heat pump type refrigeration cycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a heat pump type refrigeration cycle provided with a heat storage tank within the cycle.

(Conventional technology) In a heat pump type air conditioner, a heat storage tank is installed in the refrigeration cycle, and the heat stored in the heat storage tank is used at night to obtain heat from the heat storage tank when heating starts, thereby increasing heating capacity. It is now possible to take it out.

FIG. 3 shows a conventional heat pump type refrigeration cycle, where 1 is a compressor and 2 is a four-way valve. This four-way valve 2 includes an outdoor heat exchanger 3, an expansion valve 4 as an expansion mechanism,
The four-way valve 2 is connected to the four-way valve 2 via the heat storage tank 5 and the indoor heat exchanger 6.
It is connected to a basic heat pump refrigeration cycle. Roughly speaking, a first electromagnetic valve 7 and a rising expansion valve 8 are provided in parallel between the heat storage tank 5 and the indoor heat exchanger 6. Further, the expansion valve 4 is provided with first and second bypass circuits 9,10, the first bypass circuit 9 is provided with a second solenoid valve 11 and a check valve 12, and the second bypass circuit 1o is provided with a second solenoid valve 11 and a check valve 12. A third solenoid valve 13 and a check valve 14 are provided.

In the refrigeration cycle configured in this way, the heat storage tank 5
When heating start-up operation is performed using the heat of That is, the first solenoid valve 7 is closed,
The second solenoid valve 11 opens, and only the fan (not shown) of the indoor heat exchanger 6 is turned on, so that the indoor heat exchanger 6 acts as a condenser, and the heat storage tank 5 acts as an evaporator. Pump up the heat of 5. If this operation continues, the temperature of the heat storage tank 5 will drop, but as long as the evaporation temperature is higher than the outside air temperature, high heating capacity can be achieved by absorbing heat from the outside air.

Further, when the temperature of the heat storage tank 5 decreases and a high heating capacity cannot be achieved, the heating heat storage operation shown in FIG. 5 is started. This is a cycle that stores heat for defrosting, and the indoor heat exchanger 6
Then, the fan (not shown) of the outdoor heat exchanger 3 is turned on, and the indoor heat exchanger 6 and heat storage tank 5 act as a condenser to perform heating and heat storage at the same time. The heat stored here is used to improve defrosting performance, such as shortening defrosting time, in a defrosting cycle as shown in FIG. In other words,
The four-way valve 2 switches to become a cooling cycle, only the fan (not shown) of the outdoor heat exchanger 3 is turned on, the outdoor heat exchanger 3 acts as a condenser and defrosts, and the heat storage tank 5 becomes an evaporator. The defrosting time is shortened by utilizing the heat of the heat storage tank 5.

(Problem to be solved by the invention) In this way, the temperature of the heat storage tank 5 is low immediately after the end of the high heating capacity operation at the time of starting the heating, and the ratio of the heating capacity to the heat storage capacity is larger for the heat storage capacity. The disadvantage is that the heating capacity is reduced. In this way, there is a drawback that the heating capacity decreases for a while after the start-up is finished. In this way, the ratio of heat storage capacity to heating capacity changes as the temperature of the heat storage tank changes.

There is a drawback that when the concentration of the heat storage tank is low, the heat storage capacity increases and the heating capacity decreases.

This drawback always occurs when heat is stored while heating in a refrigeration cycle that is connected in series with an indoor heat exchanger and a heat storage tank.

This invention was made with attention to the above-mentioned circumstances, and its purpose is to temporarily control the heating capacity by controlling the heat radiation capacity to the heat storage tank at a constant level regardless of the temperature change of the heat storage material in the heat storage tank. An object of the present invention is to provide a heat pump type refrigeration cycle that can prevent such a decrease in temperature.

[Structure of the invention]

(Means and effects for solving the problem) This invention has the following features:
An electric expansion valve is provided between the indoor heat exchanger and the heat storage tank, and a temperature sensor is provided to detect the temperature of the heat exchanger and the temperature of the heat storage material of the heat storage tank. The electric expansion valve is controlled to vary the opening degree, and the opening degree of the electric expansion valve is controlled so that the temperature difference between the temperature sensors becomes constant, thereby preventing a temporary decrease in the heating capacity immediately after the heating start-up operation. The purpose is to prevent it.

(Embodiment) Hereinafter, an embodiment of the present invention will be described based on FIG. 1, and the same components as the conventional one shown in FIG. 3 will be given the same reference numerals and the explanation will be omitted.

As shown in FIG. 1, an electric expansion valve 15 whose opening degree can be freely varied is provided between the indoor heat exchanger 6 and the heat storage tank 5. An expansion valve controller 17 is connected to the section 16, and the opening degree of the electric expansion valve 15 can be adjusted by this expansion valve controller 17. Furthermore, the heat storage tank 5 has a heat storage material 1
8 and a heat exchanger 19, and this heat storage tank 5
Temperature sensors 20 and 21 are provided at the inlet and outlet of the heat storage material 18, and a temperature sensor 22 that detects this temperature is provided inside the heat storage material 18.
is provided. And these temperature sensors 20.2
1 and 22 are detected by the expansion valve controller 17.
It is now sent to .

Next, the operation of the refrigeration cycle configured as described above will be explained. When storing heat while heating, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 is introduced into the indoor heat exchanger 6 via the four-way valve 2 to heat the room. The refrigerant exiting the indoor heat exchanger 6 is led to the expansion valve 4 via the electric expansion valve 15, the heat exchanger 19 of the heat storage tank 5, and then the four-way valve 2 via the medio-outside heat exchanger 3. It is sucked into the compressor 1. During this heating operation, temperature detection signals from temperature sensors 20, 21 and 22 are input to the expansion valve controller 17. Therefore, the expansion valve controller 17 controls the opening degree of the electric expansion valve 15 so that the temperature difference between the heat exchanger temperature of the heat storage tank 5 and the heat storage material temperature is constant. For example, when heating starts, the temperature of the heat storage material T
Assume that t is 10°C and the indoor temperature Ta is 20°C. At this time, if there is no throttling mechanism between the indoor heat exchanger 6 and the heat storage tank 5 as in the conventional case, when the condensation temperature Tc is balanced at 30'C, Tc - Tt - 20 deQ, which is the case in the heat storage tank 5 with a large temperature difference. It dissipates a lot of heat and does not have enough heating capacity. but,
According to the embodiment, when Tc-Tt-5deg is set, the electric expansion valve 15 is throttled. Therefore, the condensing temperature TCt of the indoor heat exchanger 6 becomes as high as 40°C, and the heat storage tank 5
The condensation temperature TC2 is as low as 15°C and Te3-Ta-2
0deg%TCt-"rt-5deg, the heat radiation of the heat storage tank 5 decreases, and the heating capacity increases. In this case, the heat storage capacity decreases to about 1/4, but the heat is stored until the next defrosting. Even this amount is enough to store heat.

If operation continues in this state, the heat storage material 18 in the heat storage tank 5
temperature Tt becomes high, but in this case, the electric expansion valve 15 gradually opens and Tc2 increases by the same amount as the rise in Tt.
also increases, keeping Te3-Tt constant. When this state is represented on a Mollier diagram, it becomes as shown in FIG. 2, and it is possible to control the heat radiation to the heat storage tank 5 and prevent a decrease in the heating capacity.

In addition, the electric expansion valve 15 at times other than the heating heat storage operation is operated so that the temperature difference between the inlet and the outlet of the heat exchanger 19 of the heat storage tank 5 is kept constant according to the detection signal from the temperature sensor 20.21 when the heating starts. That is, the opening degree is controlled so that the amount of super heat of the heat exchanger 19 is constant, and in all other operation modes, it is fully opened.

〔Effect of the invention〕

As explained above, according to the present invention, an electric expansion valve whose opening degree can be varied is provided between the indoor heat exchanger and the heat storage tank, and the temperature of the heat exchanger and the heat storage material of the heat storage tank is detected. Since the opening degree of the electric expansion valve is controlled by the detection signal from the temperature sensor, the heat storage capacity can be controlled at a constant level regardless of temperature changes in the heat storage material, and the heating capacity can be temporarily reduced immediately after the heating start-up operation. This has the effect of being able to prevent a decline in performance.

[Brief Description of the Drawings] Figures 1 and 2 show an embodiment of the present invention, in which Figure 1 is a configuration diagram of a refrigeration cycle, Figure 2 is a Mollier diagram during heat storage capacity control operation, Figure 3 is a configuration diagram of a conventional refrigeration cycle, Figure 4 is a diagram of a refrigeration cycle during a conventional heating start-up operation using heat storage, and the fifth factor is a diagram of a refrigeration cycle during a conventional heat storage operation while heating. is a refrigeration cycle diagram during conventional defrosting operation using heat storage. 1... Compressor, 3... Outdoor heat exchanger, 4...
... Expansion valve, 5... Heat storage tank, 6... Indoor heat exchanger, 15... Electric expansion valve, 17... Expansion valve controller, 18... Heat storage material, 19... Heat Exchanger, 20-2
1...Temperature sensor. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Tt: 4 Ways of Honor Figure 2 Tout Sacred Spirit Figure 3 Figure 4

Claims (1)

[Claims] (1) A compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger are connected in sequence, and a heat storage tank is provided downstream of the indoor heat exchanger during heating operation, and the heat is stored in the heat storage tank. In a heat pump type refrigeration cycle that makes it possible to utilize the heat generated in A temperature sensor to detect and a temperature detection signal of the temperature sensor control the electric expansion valve to vary the opening degree, and control the opening degree of the electric expansion valve so that the temperature difference between the temperature sensors is constant. A heat pump type refrigeration cycle characterized by being equipped with an expansion valve controller.