JP2009097770A - Circulation flow volume calculating method for heat pump type hot water heating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calculate a circulation flow volume of a secondary side circulation circuit more accurately without using a flow rate sensor in a heat pump type hot water heating apparatus. <P>SOLUTION: In the calculating method of the circulation flow volume of secondary side heating circulation water of the heat pump type hot water heating apparatus, primary side hot water heated by a heat pump type heating means 4 is circulated to a heating heat exchanger 9, and the secondary side heating circulation water circulated to a hot water heating terminal 8 is heated. It calculates an inlet/outlet temperature difference ΔThp of the heat pump type heating means 4 of the primary side hot water, a heat pump heating capacity W estimated from an input water temperature Thpi of the heat pump type heating means 4 of the primary side hot water and an outside air temperature Ta, an inlet/outlet temperature difference ΔT1 of the heating heat exchanger 9 of the primary side hot water, an inlet/outlet temperature difference ΔT2 of the heating heat exchanger 9 of the secondary side heating circulation water, and a circulation flow volume G2 of the secondary side heating circulation water from heat efficiency η of the heating heat exchanger 9. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat pump type hot water heating apparatus in which primary side hot water heated by a heat pump type heating means is circulated to a heat exchanger for heating, and secondary side heating circulating water circulated to the hot water heating terminal is heated. The present invention relates to a method for calculating the circulation flow rate of secondary side heating circulating water.

  Conventionally, in this type of heat pump type hot water heater, the primary side hot water heated by the heat pump type heating means is circulated directly to the heating heat exchanger without going through the hot water storage tank, and circulated to the hot water heating terminal. There was something to heat the secondary side heating circulation water. (See Patent Document 1)

  In addition, in the hot water heating system, the present applicant has filed an application that attempts to balance the heating load and the amount of heat released from the hot water heating terminal in order to perform efficient heating operation with less wasted heat dissipation. Yes. (See Patent Document 2)

JP 2006-46800 A (FIGS. 1 and 4) Japanese Patent Application No. 2007-173751

  However, in order to make the amount of heat radiation in the hot water heating terminal appropriate, it is necessary to know the circulation flow rate of the secondary side heating circulating water flowing into the hot water heating terminal. In order to obtain the circulation flow rate of the secondary side heating circulation water, there was no choice but to measure the circulation flow rate by installing a flow rate sensor in the secondary side circulation circuit or to calculate the circulation flow rate from the rotational speed of the secondary side circulation pump . When a flow sensor is provided in the secondary circulation circuit, the cost is increased by the flow sensor, and when the circulation flow is calculated from the rotation speed of the secondary circulation pump, the hot water heating terminal If the pressure loss of the secondary circulation circuit, which varies depending on the installation status of the hot water heater, such as the type and number, the piping status to the hot water heating terminal, etc., is not known, the inaccurate circulation flow rate will be calculated. The amount of heat radiation at the terminal could not be made appropriate.

  Therefore, an object of the present invention is to make it possible to calculate the circulation flow rate of the secondary side circulation circuit more accurately without using a flow rate sensor.

  In order to achieve the above object, the present invention circulates the primary side hot water heated by the heat pump heating means to the heating heat exchanger and heats the secondary side heating circulating water circulated to the hot water heating terminal. It is a calculation method of the circulation flow rate of the secondary side heating circulating water of the heat pump type hot water heating device, and the inlet / outlet temperature difference ΔThp of the heat pump type heating means of the primary side hot water and the inlet temperature of the heat pump type heating means of the primary side hot water Heat pump heating capacity W estimated from Thpi and outside air temperature Ta, inlet / outlet temperature difference ΔT1 of the heating heat exchanger for the primary side hot water, and inlet / outlet temperature difference of the heating heat exchanger for the secondary side heating circulating water The circulation flow rate G2 of the secondary side heating circulating water is calculated from ΔT2 and the heat exchange efficiency η of the heating heat exchanger.

  In addition, the heat pump heating capacity W is estimated using a matrix map of the heat pump heating capacity W according to the incoming water temperature Thpi and the outside air temperature Ta that are stored and set in advance.

  Further, when calculating the flow rate G2 of the secondary side heating circulating water, the average temperature T2av of the secondary side heating circulating water is calculated, and the secondary side heating circulating water average temperature T2av is preset and stored. The circulation flow rate G2 of the secondary side heating circulating water is calculated using the relationship of the characteristic value C2.

  According to the present invention, it is possible to more accurately calculate the flow rate of the secondary side heating circulating water without using a flow rate sensor.

Next, a heat pump hot water storage type hot water supply / room heating apparatus according to a first embodiment of the present invention will be described with reference to the drawings.
1 is a hot water storage tank for storing hot water, 2 is a hot water supply pipe connected to the bottom of the hot water storage tank 1, 3 is a hot water supply pipe connected to the upper part of the hot water storage tank 1, and 4 is a heat pump type heating that circulates and heats hot water in the hot water storage tank 1 Means 5 comprises an HP forward pipe 6 connecting the bottom of the hot water storage tank 1 and the water inlet side of the heat pump type heating means 4, and an HP return pipe 7 connecting the hot water side of the heat pump type heating means 4 and the upper part of the hot water storage tank 1. It is a heat-pump circuit.

  8 is a hot water heating terminal for heating by circulating hot water, and 9 is a secondary side for circulating the hot water heating terminal 8 by circulating hot water in the hot water storage tank 1 or hot water heated by the heat pump heating means 4. Heating heat exchanger 10 for heating the heating circulating water 10 is a secondary side circulation circuit for circulating the heating circulating water between the hot water heating terminal 8 and the heating heat exchanger 9, and 11 is a secondary side circulation circuit 10. It is the secondary side circulation pump provided in.

  Reference numeral 12 denotes a primary provided with a heat exchange pipe 13 for supplying hot water to the heating heat exchanger 9 and a heat exchange return pipe 14 for returning the hot water flowing out of the heating heat exchanger 9 to the lower part of the hot water storage tank 1. A side circulation circuit, 15 is a primary side circulation pump provided in the primary side circulation circuit, 16 is a distribution valve provided at a position connected to the HP return pipe 7 and the heat transfer pipe 11, and is heated by the heat pump heating means 4 The hot water is diverted to the heating heat exchanger 9 and the hot water storage tank 1 at an arbitrary ratio.

  Reference numeral 17 denotes a primary inlet temperature sensor which is provided on the primary inlet side of the heating heat exchanger 9 and detects a primary inlet temperature T1i. Reference numeral 18 is a primary side temperature sensor which is provided on the outlet side of the primary side and detects a primary outlet temperature T1o. Side outlet temperature sensor 19 is provided on the secondary inlet side and detects the secondary inlet temperature T2i, and 20 is provided on the secondary outlet side and the secondary outlet temperature T2o is detected. It is a secondary side outlet temperature sensor to detect.

  Next, the heat pump heating means 4 will be described in detail. 21 is a compressor that compresses the refrigerant to a high pressure, 22 is a refrigerant-water heat exchanger that exchanges heat between the refrigerant and water, and 23 is open. Decompressing means for depressurizing the refrigerant whose temperature has dropped, comprising an electronic expansion valve that can be adjusted, 24 is an air heat exchanger that evaporates by evaporating low-temperature and low-pressure refrigerant and air, and 25 is an air heat exchanger The blower is forcibly sent, and the heat pump cycle 26 is constituted by these.

  27 is a heat pump circulation pump provided in the middle of the heat pump circulation circuit 5, 28 is an outside air temperature sensor for detecting the outside air temperature Ta, and 29 is provided on the water inlet side of the refrigerant-water heat exchanger 22 to detect the incoming water temperature Thpi. A heat pump incoming water temperature sensor 30 is a heat pump hot water temperature sensor provided on the water outlet side of the refrigerant-water heat exchanger 22 for detecting the hot water temperature Thpo.

  A plurality of hot water storage sensors 31 are provided on the upper and lower sides of the hot water storage tank 1 to detect the hot water storage temperature in the hot water storage tank 1, and 32 is a control for inputting the detection value of each sensor and performing an operation to control the operation of each actuator. In the apparatus, various data determined by tests and the like are set and stored.

Next, the operation of the heat pump type hot water storage type hot water heater of the present invention will be described.
First, at midnight, the control device 32 operates the heat pump heating means 4 and the heat pump circulation pump 27 to heat the water taken out from the lower part of the hot water storage tank 1 and return it to the upper part of the hot water storage tank 1 to perform the hot water storage operation. I do. At this time, the distribution valve 16 fully opens the hot water storage tank 1 side so that all the hot water boiled up returns from the upper part of the hot water storage tank 1.

  When the faucet (not shown) is opened, city water flows from the water supply pipe 2 into the bottom of the hot water storage tank 1, hot water is supplied from the upper part of the hot water storage tank 1 through the hot water supply pipe 3, and a hot water supply operation is performed. .

  Next, the operation | movement at the time of performing heating operation is demonstrated. When there is a request for the heating operation, the control device 32 operates the heat pump type heating means 4, the heat pump circulation pump 27, and the primary side circulation pump 15 and also activates the secondary side circulation pump 11. At this time, the distribution valve 16 fully opens the heating heat exchanger 9 side. Thereby, on the primary side, the low-temperature water from the bottom of the hot water storage tank 1 is heated by the heat pump heating means 4, the heated high-temperature water flows to the heating heat exchanger 9, and the hot water whose temperature has decreased is stored in the hot water storage tank 1. While returning to the lower part, on the secondary side, the heated circulating water heated by exchanging heat in the heating heat exchanger 9 is circulated to the hot water heating terminal 8 for heating, and the heated circulating water whose temperature has decreased is heated again. It circulates to the heat exchanger 9 for use.

  When the heating capacity W of the heat pump heating means 4 is larger than the heating load, the control device 32 distributes the high-temperature water heated by the heat pump heating means 4 to the heating heat exchanger 9 side and the hot water storage tank 1 side. The amount of heat flowing into the heating heat exchanger 9 side is controlled by setting the distribution ratio to an appropriate ratio. Here, the value of the ratio of the primary-side hot water distributed to the heating heat exchanger 9 side is assumed to be dr.

  In this heating operation, in order to balance the heating load and the amount of heat released by the hot water heating terminal, it is necessary to know the circulation flow rate of the secondary side heating circulating water flowing into the hot water heating terminal, but the method described below Thus, the control device 32 calculates the circulation flow rate of the secondary side heating circulating water.

  First, in step 1 of FIG. 2, the outside air temperature Ta detected by the outside air temperature sensor 28, the incoming water temperature Thpi detected by the heat-pump incoming water temperature sensor 29, and the outdoor air temperature Ta and incoming water temperature Thpi previously stored in the control device 32. From the matrix map of the heat-pump heating capability W based on (see Table 1), the heat-pump heating capability W is determined.

  Next, in step 2, the secondary side heating temperature is detected from the secondary side inlet temperature T2i detected by the secondary side inlet temperature sensor 19 and the secondary side outlet temperature T2o detected by the secondary side outlet temperature sensor 20. An average temperature T2av is calculated.

  In step 3, the characteristic value C2 at the average temperature T2av is determined from the relationship between the temperature of the circulating circulating water and the characteristic value C2 stored in advance in the control device 32 (see FIG. 3). Here, the characteristic value C2 of the heating circulating water indicates a value based on the specific heat and density of the heating circulating water.

  Then, in steps 4 to 7, the circulation flow rate G2 of the secondary side heating circulation water is calculated by the heat exchange efficiency η of the heating heat exchanger 9 set and stored in advance and the following formula 1 set and stored in advance. To do.

ここで、ΔＴ１＝Ｔ１ｏ−Ｔ１ｉ
ΔＴ２＝Ｔ２ｏ−Ｔ２ｉ
ΔＴｈｐ＝Ｔｈｐｏ−Ｔｈｐｉ

Here, ΔT1 = T1o−T1i
ΔT2 = T2o−T2i
ΔThp = Thpo−Thpi

  As described above, according to the circulation flow rate calculation method for the heat pump type hot water heating apparatus of the present invention, the type and number of the hot water heating terminals, or the piping conditions to the hot water heating terminals, etc., differ depending on the installation situation of the hot water heating apparatus. Even if the pressure loss of the secondary circulation circuit is not known, the flow rate of the secondary heating circulation water can be calculated more accurately without using a flow rate sensor, and the amount of heat radiation at the heating terminal is made appropriate. Therefore, it is possible to realize efficient hot water heating with less temperature fluctuation and unnecessary heat dissipation.

  Further, the heating capacity W of the heat pump type heating means 4 is influenced by the outside air temperature Ta and the incoming water temperature Thpi, but the influence is obtained in advance by a test or the like, and is stored in the control device 32 as a matrix map. It is possible to accurately calculate the flow rate of the secondary side heating circulating water even in various situations such as the temperature Ta and the incoming water temperature Thpi changing with the passage of time.

  Furthermore, when the antifreeze is used as the secondary side heating circulation water, the specific heat and the density greatly change according to the temperature change, but the relationship of the characteristic value C2 that is the product of the specific heat and the density according to the temperature of the antifreeze used. Is stored in the control device 32, it is possible to calculate a more accurate flow rate of the secondary side heating circulation water in consideration of the temperature change of the antifreeze liquid.

  Here, means (not shown) for setting the concentration of the antifreeze actually used in the hot water heater is connected to the control device 32, and the control device 32 has a characteristic value according to the set concentration. C2 may be corrected. As a result, even if the concentration of the antifreeze is different, the flow rate of the secondary side heating circulating water can be calculated more accurately. Examples of the means for setting the concentration of the antifreeze liquid include a configuration in which a DIP switch is provided on the circuit board of the control device 32 or can be set by a specific operation with a remote controller.

1 is a system diagram of a hot water heater according to an embodiment of the present invention. The figure explaining the calculation method of this invention. The characteristic figure with respect to the temperature of secondary side heating circulation water.

Explanation of symbols

4 Heat pump type heating means 8 Hot water heating terminal 9 Heat exchanger for heating

Claims (3)

  The secondary side heating of the heat pump type hot water heating apparatus in which the primary side hot water heated by the heat pump type heating means is circulated to the heating heat exchanger and the secondary side heating circulating water circulated to the hot water heating terminal is heated. A method for calculating a circulating flow rate of circulating water, which is estimated from the inlet / outlet temperature difference ΔThp of the heat pump heating means of the primary side hot water, the inlet temperature Thpi of the heat pump heating means of the primary side hot water, and the outside air temperature Ta. Heat pump heating capacity W, primary side hot water entrance / exit temperature difference ΔT1 of the heating heat exchanger, secondary side heating circulating water entrance / exit temperature difference ΔT2, and the heating heat exchanger A circulation flow rate calculation method for a heat pump type hot water heating apparatus, wherein the circulation flow rate G2 of the secondary side heating circulation water is calculated from the heat exchange efficiency η.   2. The heat pump type heat pump according to claim 1, wherein the heat pump heating capacity W is estimated using a matrix map of the heat pump heating capacity W corresponding to the pre-stored water temperature Thpi and the outside air temperature Ta. Circulating flow rate calculation method for hot water heater.   When calculating the flow rate G2 of the secondary side heating circulating water, the average temperature T2av of the secondary side heating circulating water is calculated, and the characteristic value according to the preset average temperature T2av of the secondary side heating circulating water The method for calculating the circulation flow rate of the heat pump type hot water heating apparatus according to claim 1 or 2, wherein the circulation flow rate G2 of the secondary side heating circulation water is calculated using the relationship of C2.

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